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A Trainer Resource Package forSpecialist Concrete Operations

Diamond drilling, sawing and related techniques

CTP 143/D

Johns drilling & sawing: drilling & sawing 22/11/07 14:47 Page I

Published by ConstructionSkillsBircham Newton, King’s Lynn, Norfolk PE31 6RH

First published 2007

© Construction Industry Training Board 2007

The Construction Industry Training Board otherwiseknown as CITB-ConstructionSkills and ConstructionSkills

is a registered charity (Charity Number: 264289)

Acknowledgements

ConstructionSkills would like to thank the Drilling andSawing Association and the following companies

for their contribution in producing this resource material

Technical input

Hilti (Great Britain) Ltd

Husqvarna Construction Products

Tyrolit Ltd

Nimbus Diamond Products

ICS-Blount

Xcalibre Equipment Ltd

Author

Joel Vinsant(Training & Assessment Consultants Ltd)

Layout/Illustrative work

Marketing For Growth Limited

ConstructionSkills has made every effort to ensure thatthe information contained within this publication is accurate.Its content should be used as guidance material and not asa replacement for current regulations or existing standards.

Printed in the UK

CITB-ConstructionSkills, CIC and CITB (Northern Ireland) are working as ConstructionSkills, the Sector Skills Council for Construction.

Skills for Business is an employer-led network consisting of 25 Sector Skills Councils and the Sector Skills Development Agency. Throughlabour market intelligence, the identification of skills needs at all levels and its influence on the UK’s education and learning infrastructure,the network aims to increase productivity in business and public services.

Johns drilling & sawing: drilling & sawing 22/11/07 14:47 Page II

Guide to sections guide

1Specialist concrete operations© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D

Notes to trainers 2

1 Introduction 14

2 Tools and equipment 22

3 Materials and components 44

4 Hand sawing 54

5 Diamond drilling 83

6 Floor sawing 93

7 Track/wall sawing 101

8 Bursting 117

9 Crushing 129

10 Wire sawing 139

11 Standards, regulations and guidance documents 167

12 Glossary of terms 172

Johns drilling & sawing: drilling & sawing 22/11/07 14:47 Page 1

Introduction

This trainer resource package provides support materials for the Construction SkillsTraining Programme, specific to the diamond drilling and sawing industry, encompassing,the drilling, sawing and ‘controlled demolition’ (crushing and bursting) of concrete andmasonry structures, for the purpose of modification, repair or dismantling.

The package consists of sections tailored to deliver the basic underpinning knowledgerequired by an NVQ/SVQ at level 2. It also lists the training objectives for each part ofthe programme and has been approved by the working group responsible for thedevelopment of the Occupational Standards.

Some sections contain more technical information than is strictly necessary for thetraining of operatives. However, this will broaden the knowledge of trainees, provide areference source and enable trainees to better understand the technology involved.

Use

The material is designed to allow maximum flexibility in its use and is not dependent onany particular training method. The package consists of a number of sections which canbe delivered progressively or on a modular basis. Each section is subdivided into anumber of ‘subject areas’, each with its own introduction. The sections are thereforeideal for copying and handing out to trainees. Trainers are free to deliver the completeprogramme or to choose the sections relevant to their needs.

Health, safety and welfare

Attention is drawn throughout these training materials to the hazards and risks to healthand safety associated with occupations that undertake drilling and sawing operationsinto concrete/masonry structures. Training providers should aim to get trainees into thehabit of evaluating the health and safety requirements of a particular task, assessing therisks for themselves, deciding what control measures are needed and how they shouldbe applied, and in selecting and using the appropriate personal protective equipmentwhen the risks cannot be controlled by other means.

Trainees should have a full understanding of what their responsibilities are for health andsafety, and which are employers’ responsibilities. If that is achieved, trainees will be in abetter position when they are on site to ask questions about risk assessments, methodstatements, safe places and systems of work, and perhaps to refuse to work unsafely.If we can encourage this approach within the workforce then, hopefully, levels of healthand safety on site will improve. Trainees should also be made aware of their employer’sresponsibility to ensure that adequate welfare facilities are provided and the possibleneed to question the situation when they are not provided.

It must be emphasised that the drilling and sawing of concrete and masonry structureshas the potential to cause serious health problems if the risks are not adequatelycontrolled. The way to determine the particular hazards associated with individualactivities, and the required level of risk control, is through carrying out appropriate andsufficient risk assessments

Notes to trainers notes



Risk assessments

The Management of Health and Safety at Work Regulations require that a risk assessmentis carried out for every work task to be undertaken. This assessment is intended toidentify any risks to health and safety which may be inherent in the task, and to detailany control measures which must be put in place to reduce the risks to an acceptablelevel. Risk assessments must be carried out by someone competent in the work activitybeing assessed to enable all the threats to health and/or safety to be identified.

Risk assessments must be suitable and sufficient, which takes into account such factorsas the complexity of the task and the competency of the person(s) undertaking the work.The findings of the assessment should be written down so that any person with aninterest in its content (for example an HSE Inspector or a main contractor) can checkthat statutory requirements have been met and potential problems identified. Written riskassessments may be stored in an electronic format providing copies can be retrievedand printed if requested.

Ideally, the risk assessment process would identify methods of working which would notput anyone’s health or safety at risk. It is obvious, however, that in practice this is oftennot possible, although the work techniques available to those involved in diamonddrilling, sawing and related techniques, can significantly reduce the risks.

The following list, which is not exhaustive, highlights areas that should be consideredwhen carrying out a risk assessment:

• The competence and experience of the person(s) who will carry out and/orsupervise the work

• The adoption of safe and healthy work procedures and practices – means ofaccess and egress, availability of manufacturers' information, training that hasbeen undertaken or is required

• The physical environment in which the work is to be carried out

• Fire precautions and procedures – availability of fire extinguishers, means ofescape, alarms, etc.

• The possible need for health surveillance

• Manual handling – avoidance of potentially harmful manual handling but, wheremanual handling is necessary, the use of correct lifting procedures

• The control and suppression of silica and other harmful dusts by such techniquesas wet-cutting or vacuum extraction

• The adoption of other control measures in preference to using personal protectiveequipment (PPE)




• The need for PPE where the risks cannot be controlled by other means –availability, proper fit and adequate maintenance of the correct type, and suitablefor the task, for example:

– safety helmets, to protect the head from falling objects and knocksNote: The wearing of safety helmets in most situations is required by law

– waterproof gloves, to protect against cuts, abrasions, chemicals, contaminants, etc.

– eye protection, for use in the proximity of dust, hazardous substances, flyingparticles, etc.

– respirator or filtering face masks, to prevent the inhalation of dust, toxic particles,etc., or contact with substances harmful to the skin

– hearing protection, to protect against noise

– overalls, to prevent contact with dust, chemicals, etc. and to cover any looseclothing

– safety footwear, to protect the feet from falling objects and injuries caused bycrushing, and to reduce the risk of foot or ankle injuries

– rubber boots with steel toe caps, for use in wet/muddy conditions.

Health risks which are particularly associated with diamond drilling, sawing and relatedtechniques are:

• manual handling – sawing machines and associated equipment often requirehandling/operation by two operatives. This may also apply to the removal ofstructural material which has been detached by drilling or sawing (See Note overleaf)

• respiratory problems – the potential for contracting serious respiratory diseases,such as occupational asthma, resulting from the inhalation of silica and otherharmful substances

• vibration white finger – resulting from the prolonged use of percussive or cuttingequipment

• noise induced hearing loss – caused by failing to protect the hearing whenworking in noisy environments

• dermatitis and other skin complaints – resulting from the failure to protectexposed skin from contact with harmful dusts, slurry etc., or persistently workingwith wet hands

Safety risks which are particularly associated with diamond drilling, sawing and relatedtechniques are:

• structural integrity – operations must be undertaken with an understanding of thestructural implications of the work being carried out (this applies to the structureitself and also to any adjoining structural elements)

• use of cutting equipment – diamond drilling, sawing and related techniques carrya potential hazard because of the nature of the cutting equipment




• unsupervised work – operators are often required to work in small teams(typically in pairs) without direct supervision.

Note: Trainers should stress to trainees that poor manual handling is the most commoncause of lost time due to accidents. However, the good training they shouldreceive and the proper following of company and site rules, along with otherhealth and safety procedures they have been shown, will enable them to worksafely and without risk to their health, or to the health and safety of others whomay be affected by what they do.

Other health and safety regulations specify the way in which associated work activitiesmust be carried out and the duties placed on employers and employees to ensure theyare. A summary of the regulations relevant to drilling, sawing and related activities areincluded under the heading Summary of relevant health and safety legislation, whichfollows later.

As mentioned previously, trainees will be better placed when they start work if they havea clear understanding of their personal duties and responsibilities as regards their ownhealth and safety, and the health and safety of others who may be affected by what theyare doing. The main employee health and safety responsibilities and duties are listed below.

Employee health and safety responsibilities

1. Co-operate with the employer and follow any information, instructions and trainingthat is given.

2. Do not interfere with, or misuse anything, that the employer has provided in theinterests of health, safety or welfare.

3. Take care at all times and make sure that you do not endanger yourself or anyother person.

4. Use all tools and equipment safely and in accordance with instructions given ortraining received.

5. Do not use any items of plant, tools or equipment unless you are authorised to do soand are competent to use them.

6. Report any defects in equipment or potential hazards to a supervisor as soonas possible.

7. Do not remove any safety guards or render inoperative any safety device fitted toany equipment.

8. Use personal protective equipment supplied by the employer correctly, take care of itand report any loss or defects.

9. Report to a supervisor any work situation that might present a danger.

10. Follow all company and site health and safety rules.




11. Recognise the importance of personal cleanliness, especially when working withsubstances harmful to the skin or hazardous to health.

12. Wear hearing protectors in designated areas where signs are displayed.

13. Understand and comply with all signs and notices that are displayed.

14. Report to a supervisor all accidents that cause an injury.

Training objectives

Training objectives are listed at the start of each section. They are included to helptrainers direct the use of material within the training programme.

Standards, regulations and guidance documents

Industry standards, regulations and guidance sources are listed in Section 11. The list isnot exhaustive and, because these sources are subject to periodic updates and revisions,trainers will need to ensure that current information is available.

An appreciation of the relevant standards and guidance documents will help to ensurethat a good standard of work is achieved and that client expectations are achieved.

Copyright

This material has been prepared as a photocopiable resource. It may be freely copied fortraining purposes without further permission from ConstructionSkills on the conditionthat it is used solely within the purchasing organisation and is not used for profit or gain.

Summary of relevant health and safety legislation

1. The Health and Safety at Work etc. Act 1974

This is the main piece of health and safety legislation. It requires employers to providesafe places of work and safe systems of work. Provided for the establishment of theHealth and Safety Commission (HSC) and Executive (HSE) and their powers, it alsocovers the penalties which can be imposed by courts if an offence is committed.

2. The Management of Health and Safety at Work Regulations 1999

These regulations, amongst other things, place a legal requirement on employers toassess the risks to health and safety which arise out of their work activities and tointroduce measures which control the risks to an acceptable level. Schedule 1 to theregulations indicates the General Principles of Prevention which must be adhered towhen deciding upon risk control measures. Some of the general principles lendthemselves to being applied to diamond drilling, sawing and related activities, such as;

• Avoiding the risk – for example, using floor-standing or rail-mounted rigs ratherthan hand-held equipment to totally avoid hand/arm vibration




• Combating risks at source – for example, suppressing dust by wet cutting ratherthan relying solely on PPE

• Replacing the dangerous with the non-dangerous or less dangerous – for example,using bursting or crushing equipment, rather than sawing, to eliminate or reducenoise and vibration

• Adapting to technical progress – for example, buying new work equipment whichis designed to vibrate less than older type equipment. Keeping equipment wellmaintained will also reduce vibration.

The regulations also put legal duties on employers with regard to:

• providing employees with comprehensive information of the risks identified by theassessment and the measures implemented to control those risks

• ensuring that employees are capable (in all respects) of carrying out the work thatthey are required to do in a safe manner and without risks to health

• co-operate with other employers (where the employees of more than oneemployer share a workplace), in the interests of health and safety

3. The Construction (Design and Management) Regulations 2007

These regulations, often referred to as CDM, replace the the CDM Regulations 1994(as amended) and the Construction (Health, Safety and Welfare) Regulations 1996, andamend the Workplace (Health, Safety and Welfare) Regulations 1992 (as amended) withthe effect that some of these regulations now apply to construction sites.

These regulations place a clear emphasis on the need for everyone on site to becompetent, for co-operation between all parties on site, and for the co-ordination ofwork activities so as to avoid, or reduce, health and safety risks. The main contractor(or principal contractor if the project is notifiable) must ensure that these requirementsare complied with.

Projects which are expected to last over 30 days, or 500 person days, must be notifiedto the HSE. On these projects:

• the client must appoint a principal contractor and a CDM co-ordinator

• the principal contractor must have a health and safety plan which contains the riskassessments for all of the work which will be taking place

• the site must have clear health and safety rules, and employees on site must havethe opportunity to express their opinion, as regards safety provisions

The CDM Regulations 2007 are supported by an Approved Code of Practice andGuidance Notes.




4. The Control of Substances Hazardous to Health Regulations

These regulations, often referred to as COSHH, include the following requirements:

• know the product or substance you are to work with, e.g. concrete

• assess the health hazards, e.g. inhalation of dust, dermatitis, burns

• eliminate or control the hazard, e.g. prevent or reduce exposure, use effectivecontrol measures, use personal protective equipment (PPE) as a last resort

• provide information, instruction, training and supervision, e.g. the risk ofdermatitis, controls, use of PPE

• provide appropriate health surveillance, e.g. hearing tests, lung function tests,skin checks

• monitor the effectiveness of controls, e.g. increase in skin conditions when glovesare not worn

• keep records of monitoring and health surveillance

• prepare accident, incident and emergency plans, e.g. first aid, fire procedures,contact with emergency services.

5. The Provision and Use of Work Equipment Regulations

These regulations, often referred to as PUWER, require that:

• equipment is designed for its intended purpose

• consideration is given to the working conditions and the health and safety of theperson(s) where the equipment is to be used

• equipment is used only for operations and under conditions where it is suitable

• equipments is maintained and inspected as is appropriate.

Employers must always consider:

• the nature and condition of the equipment

• the place where it is to be used

• the purpose for which it is to be used

• its suitability for the job in hand.

Information, instruction, training and supervision must include:

• conditions and methods in which the equipment will be used

• any foreseeable abnormal conditions and appropriate action

• any conclusions drawn from experience with using the equipment




• safe working methods

• possible risks that may be found and precautions to be taken.

With particular regard to sawing, due attention must be paid to the requirement forcompetence in those workers who mount (fit) and/or use abrasive wheels due to theinherent risk of the wheels breaking up when rotating at high speed if these activities arenot carried out safely. The HSE publication ‘Safety in the use of abrasive wheels’(HSG17) provides further details.

6. The Manual Handling Operations Regulations

These regulations place legal duties on both the employer and the employee.

The employer must attempt to avoid the need for manual handling, which involves a riskof injury, by identifying other suitable ways of moving loads. Where this is not possible,the employer should assess all tasks that involve a risk of injury by:

• undertaking a risk assessment of each task

• implementing control measures to reduce the risks

• providing suitable training and information to employees

• reviewing risk assessments when necessary, e.g. when there is a change in task.

The employee must co-operate with the employer by:

• using appropriate equipment as they have been instructed

• working according to the method statement or work instructions.

When lifting, consider – TASK, INDIVIDUAL, LOAD, ENVIRONMENT.

7. The Control of Noise at Work Regulations 2005

These regulations require that employers assess the noise levels which employees areexposed to while they are working, and then to prevent or reduce the risk to health fromthe exposure to noise by reducing the level of the noise. The main hazard to health isdeafness which can be caused by very high noise levels over a short period of time, orlower noise levels over a longer period of time.

If the noise level exceeds certain figures, employers must provide employees withinformation on the levels. A noise level is too high if you have to raise your voice to havea conversation with someone who is about 2 metres away.

When employers have done everything that they can to reduce the noise, yet it is stillabove certain levels, they must provide hearing protection for employees. This may beear plugs or ear muffs, and employees must be trained in how to use, and look afterthem, properly.

At higher noise levels, employers must create ‘hearing protection zones’, identify themby signs, and ensure that everyone entering the zones wears hearing protection.




8. The Electricity at Work Regulations

These regulations mainly deal with the safety of fixed electrical installations, but they dorequire that persons are competent, and that safe systems of work are implemented, ifan electrical hazard exists.

All necessary information, instruction, training and supervision must be given, andwritten safe systems of work should form part of the ‘permit to work’ procedure.

9. The Control of Vibration at Work Regulations 2005

The use of hand held tools which cause vibration will expose the user to a risk ofhand-arm or whole body vibration. This vibration damages the nerves and blood supplyand can cause vibration white finger. This shows up as a loss of feeling in the fingers,pins and needles, numbness and blanching (going white) at the ends of fingers. It isusually worse in cold weather.

Employers have a duty to risk assess the use of vibrating tools, and then to eithereliminate any risk they pose or to limit the use of vibrating tools so that limits set out inthe regulations are not exceeded. One way of doing this is work sharing or job rotationon the tools.

Newer tools have been designed to produce a lot less vibration. ‘Anti-vibration’ glovesdo not have much effect in reducing the harmful effects of vibration, although they mayhelp a little by keeping the hands warm.

10. The Work at Height Regulations 2005

Above ground, there is no safe working height!

A high percentage of fatalities and serious injuries in the construction industry arecaused by falling from height. The main hazards include falls from the edges of flat orsloping roofs, falls through fragile roof materials, and falls from ladders and scaffolds.‘Work at height’ means working in any place from which a fall from that height would belikely to result in personal injury.

Before work commences, the Work at Height Regulations require that employers assessthe work, eliminate the need to work at height or, if that is not possible, to prepare riskassessments and method statements. These must show the hazards that have beenidentified and the control measures to be implemented to produce a safe system ofworking at height. Another requirement of the regulations is that everyone who works atheight, or plans/supervises such work, must be competent or under the supervision of acompetent person.

A safe means of escape must exist for all roof work.




When preparing the method statement, first ask the question:

• is working at height the only option?

If the answer is ‘yes’, prioritise the following safety provisions as follows:

• edge protection in the form of guard rails and toe boards

• fall arrest equipment for all – e.g. safety nets

• fall arrest equipment for the individual – a harness.

11. The Confined Spaces Regulations

Work in confined spaces is always potentially hazardous!

A confined space is one which is substantially, though not always entirely, enclosed.It is a place where there is a reasonably foreseeable risk of serious injury resulting fromexposure to hazardous substances or other conditions, e.g. a cellar or an inadequatelyventilated basement room, manhole, ceiling void or duct.

The three main dangers to operatives are:

• suffocation from lack of oxygen

• inhalation of a toxic atmosphere

• injury from combustion of a flammable atmosphere.

There may be other dangers associated with the unexpected start-up of machinery orexposed electrical conductors, etc.

For working in confined spaces, employers must ensure a safe system of work. This willinclude proper procedures that are reviewed and updated regularly, risk assessments,method statements, a permit to work system, and details of adequate rescue facilities.

12. Work in excavations

Most deaths occur in trenches of less than 2.0 metres in depth. The main regulationscovering work in excavations are CDM, the Management of Health and Safety at WorkRegulations, PUWER and the Confined Spaces Regulations.

A competent person must always be responsible for an excavation and its support work.

For a safe system of work in excavations, items to be considered should include:

• inspection of the excavation as detailed in the regulations

• safe access and egress

• suitable lighting and guarding – consider trespassers




• use of suitable PPE – helmet, gloves, respiratory protection

• edge protection from plant and equipment

• risk assessments and method statements

• permit to work system in place

• buried services, e.g. electricity, cables and pipes.

For buried services: PLAN the work to be done, LOCATE AND RECORD the servicesbefore digging, and DIG using a safe method of work.

13. Personal Protective Equipment at Work Regulations

Employers must provide, free of charge, any personal protective equipment or clothing(PPE), or any respiratory protective equipment (RPE) which the employer’s risk assess-ment has identified as being necessary for employees to carry out their work safely andwithout risks to their health.

The use of PPE and RPE must only be resorted to when there are no other reasonablypracticable ways of controlling the risks. PPE and RPE will protect the wearer, but only ifit is the correct PPE or RPE for the job, in good condition and used properly. Where RPEis used, ‘face-fit’ testing should be carried out by a competent person to ensure that itforms a good seal around the face.

Important factors that must be considered in connection with diamond drilling, sawingand related techniques are:

• eye protection must be selected so that it is appropriate for the specific hazard,e.g. high speed impact of flying particles, fine dusts or a slurry spray

• with regard to respiratory protection, a filtering face mask (or an appropriaterespirator) must be selected by a competent person. ‘Nuisance dust masks’, asare available through DIY supermarkets and other retail outlets, are notmanufactured to the required standards and should not be regarded as RPE.

Other regulations

There are numerous other sets of regulations, each dealing with the health and safetyaspects of a particular issue. There are too many to list in full but a selection of topicareas covered is given below.

• Accident reporting

• Asbestos

• Compressed gases (LPG)

• Consultation with employees

• Electricity

• Environmental protection




• Fire

• First-aid

• Lead

• Lifting equipment

• Safety signs and signals.

Health and safety guidance

The Health and Safety Executive and Commission publish a wide variety of guidancematerials in connection with the way in which employers should implement theregulations. These include the following.

• Noise at work: Guidance for employersPublication number INDG 362.

• Dust control on concrete cutting saws used in the construction industryPublication number CIS 54.

• Protecting the public: Your next movePublication number HSG 151.

Other relevant safety publications including the Drilling and Sawing Association Code ofPractice are listed in Section 11.2 Safety Publications. A catalogue of publications canbe obtained, and orders placed with, HSE Books. Telephone: 01787 881165;website www.hsebooks.co.uk

Environmental considerations

The cooling water and slurry produced by some sawing and drilling operations could bedamaging to the environment if it is allowed to enter drains or water courses. All suchpollution incidents are in contravention of the Environmental Protection Act.The Environment Agency, who enforce all environmental legislation, have similar powersof enforcement as the HSE and can stop a job if they think that pollution is being (or willbe) created. The employer might find it useful to seek the advice of the EnvironmentAgency so that the workers carrying out sawing and drilling can be given clear instructionupon how to deal with any slurry or contaminated water produced. Alternatively, theclient may specify that all cutting fluids are removed from site by the cutting contractor,in which case an authorised and legal method of disposal will have to be developed.

Health and safety icons

At various places throughout the text of this Trainer ResourcePack, the ‘Health and safety icon’ is displayed. This is to drawthe trainees attention to particular health and safety issueswhich are relevant to the passage of text. Trainees may find ituseful, or necessary, to refer back to the relevant text in thisSection to remind themselves of the full details.




Section 1 Introduction 1.0

14Section 1 Introduction© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D

OTHER SECTIONS IN THIS PACK

Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139



1.0 Training objectives 15

1.1 General 16

1.2 Overview of drilling, sawing and related techniques 17

1.3 Contract documentation 18


1.1 Understand the scope of this manual.

1.2 List the main types of equipment used.

Explain why the overall process, comprising the various diamond drilling,sawing, cutting, bursting and crushing tasks, is sometimes referred to as'controlled demolition'.

Explain why it is important that only skilled, fully trained operatives areemployed to carry out the work.

1.3 Explain why it is important to complete the relevant contract documentation.

Explain the purpose of a contract Record Sheet.

Explain the purpose of a Method Statement.

Training objectives 1.0



Scope

This resource package sets out to provide a structured programme of formal training foroperators across the full range of current techniques. Not all firms, however, will employall of the techniques described. The training must be supported by practical tasks, withtrainees carrying out appropriate work under the supervision of an experiencedoperator/trainer. It is the responsibility of the trainers to demonstrate the various types ofmachines and equipment used to undertake drilling, sawing and related techniques.

The training notes should be used in a flexible manner, and augmented if necessary inorder to reflect the types and models of equipment (and their respective operatingprocedures) used in the company. However, whilst the various makes and models oftools and equipment will vary in their design and appearance, the same basic principleswill apply.

Completion of a structured training programme using this resource package, togetherwith verification and assessment of practical experience elements for the various activities,should provide sufficient evidence to enable an operative to achieve an NVQ Level 2in Drilling and Sawing. This, in turn, should lead on to the issue of a CSCS Card forthis trade.

General 1.1



Introduction

Diamond drilling and sawing is a construction industry trade which is undertaken byspecialist sub-contractors. Work is typically carried out on existing concrete andmasonry structures that require conversion, repair or refurbishment. The range oftechniques employed falls into three main categories.

• Diamond drilling using core drill bits and drilling machines to form holes.

• Diamond sawing using circular, chain and wire cutting equipment to operate handtools, pulley driven tools, track mounted and self-propelled floor saws.

• Associated tasks such as bursting, crushing and thermal lancing.

The activity as a whole is often referred to as 'controlled demolition', i.e. part or completestructures are demolished and removed in a safe and structured manner. The differenttechniques are used either singly or in combination. Typical tasks undertaken includethe following.

• Drilling holes for service ducts.

• Removal of sections from walls and floors.

• Conversion work or modifications to concrete and masonry structures,e.g. power stations, jetties and bridges.

• Sawing and drilling in civil engineering contracts, e.g. building roads, motorwaysand airport runways.

Work is carried out strictly to the client's specification. The main (or principal) contractorthen defines the scope of the work which is to be undertaken by the specialistsub-contractor. It is essential that skilled, experienced operators are employed by thesub-contractor for the reasons which follow.

• Complex machines are used which cost a great deal of money.

• The operations carry a potential hazard because of the nature of theequipment used.

• There must be an awareness of the effect that the work being carried out will haveon the structure and any implications for surrounding areas/adjoining structures.

• Operators are often required to work in small teams, typically in pairs, withoutdirect supervision.

It is vital that safe working procedures are followed at all times,and that these are underpinned by full contract documentation.

Overview of drilling, sawing and related techniques 1.2


Competence


Introduction

Both the contractor and the client will benefit if all details of the work undertaken areagreed well before the due starting date and put down in writing on a Record Sheet.Some contractors fill out simple quotation forms that are signed by the client andeffectively determine the basis of the job. However, formal Record Sheets are morerigorous and will remove any doubts should problems be encountered during thecontract or after it is completed. A Method Statement(s) will also need to be issued.Method Statements are closely linked with risk assessments (refer to Notes to trainers,Risk assessments at the front of this resource package). An example of a Record Sheetand a Method Statement are given in this section.

Record Sheet

It is advisable to have all the possible options listed on the Record Sheet. This will serveto prevent any oversights, clarify what is to be done for the benefit of both parties and,ultimately, speed up completion of the job. The Record Sheet can be used in legaldisputes as it provides evidence of the work specification that has been agreed by allparties. It is therefore important that all information on the sheet is completed fully andaccurately.

Two items that are not always found on Record Sheets are a section detailing anychanges agreed during the work and a place for signatures acknowledging andauthorising the changes. It is necessary to have two identical copies of the sheet – onekept by the client and the other by the contractor carrying out the work. Both copiesshould be available on site.

The Record Sheet typically includes:

• date

• site address

• description of work

• location, i.e. where on the site the work is to be carried out

• client and contractor contact details

• other relevant information, e.g. standing time, extras, agreed changes/variations

• signature of client and contractor representatives.

A sample Record Sheet is shown on the following page.

Contract documentation 1.3





C O M P A N YL O G O

Company telephone number(s)

Customer/Client

Site address

Site induction received Yes No Number of hours 1 2 3 4 5

Site contract Contract no.

Description of work Area of work

Standing time and reason

Extra information Extra plant on site

We certify that times and measurements contained in this document are correct and thatthe work has been carried out to our satisfaction.

For the company For the client

Contract Record Sheet

Date

Driller

Van reg


Method Statement(s)

Introduction

A Method Statement details exactly how the work is to be carried out. The objective isto ensure that contract works are conducted safely and without risk to health. They formpart of management procedures in respect of the project and provide importantinformation for contractors and operatives who will carry out the work. Two copies arenormally provided; one for the client and one for the contractor.

Method Statements typically include the following information:

• date

• client and contractor contact details

• who will supervise the work

• the qualifications of the operatives who will carry out the work

• method of work

• plant and equipment to be used

• location where the work will be carried out

• description of the work

• sequence of works

• safe systems of work

• method of communicating the method statement to operatives

• signature of supervisor.

A sample Method Statement is shown on the following page.



Co-operationand co-odination




1. Description of work

2. Supervisor responsible for work

3. Equipment to be used

Provision of suitable equipment including:

– diamond coring rig

– appropriate size and type of core drill bit

– temporary power and water source (where necessary)

– power tools, e.g. for fixing

– dust control equipment

– water control equipment

– other (specify in 8.)

4. Work area

Check with client in respect of:

– marking out of work

– location of live services

– safety of working area and control of access

– interface with other contractors

– compliance with Health & Safety procedures/plan

Arrange where appropriate:

– sequence of work (specify in 9.)

– support of cut sections

– cordoning and signage in the work area

– removal of debris

5. Installation/operation

– Position drill rig and fix securely

– Fit drill bit

– Connect power and water

– Drill to required depth

– Remove cores from work area

Method statement Diamond core drilling operations

Project: Document no:

Contractor: Assessor:

Client: Date:

6. Operative(s) qualifications

7. Arrangements for instructionof operatives

8. Details of additional equipmentrequired

9. Detailed sequence of work

All drilling to be carried out in accordance with the standards definedin the Drilling and Sawing Association’s code of safe working practice.

Supervisor Date


Section 2 Tools and equipment 2.0

22Section 2 Tools and equipment© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




2.1 Safety and general 24

2.2 Hand tools 26

2.3 Specialist tools and accessories 28

2.4 Power supply and power tools 33

2.5 Equipment and plant 35

2.6 Access equipment, barriers and signage 37

2.7 Maintenance of tools and equipment 39

2.8 Power sources for portable power tools 41


2.1 Explain why it is important to keep checklists of tools required for each job.

Explain why it is important to select the correct tool for the job.

List the items of personal protective equipment which may be required whenworking on site.

List other items that may be required in order to satisfy site safety procedures.

2.2 List the hand tools required for diamond drilling, sawing, and related techniques.

2.3 List the specialist tools and accessories required for diamond drilling, sawing,and related techniques.

2.4 List the power supply items and power tools required for diamond drilling, sawing,and related techniques.

2.5 List the equipment and plant required for diamond drilling, sawing, and relatedtechniques.

2.6 List the access equipment required for carrying out diamond drilling, sawing, andrelated work safely.

List the typical types of barriers required for carrying out diamond drilling, sawing,and related work safely.

Give examples of safety signs that may be required.

2.7 Explain how tools and equipment for diamond drilling, sawing, and related work aremaintained and stored.

Refer to manufacturer's/supplier's literature for details of tools and equipment.

List the safety checks required when using portable air- or power-driven tools.

2.8 Explain the alternative power sources used for power tools.

State the voltage rating for electrical power tools used on site.




Introduction

The items of tools, plant and equipment described in this section will differ depending oneach manufacturer's design(s). Their purpose and use, however, remain the same.The listing is not exhaustive – new tools appear periodically and contractors will havepreferences to suit particular applications.

The selection of the right tools for the job, together with proper use and maintenance,are essential for safe and efficient production of good quality work.

It is good practice to have a list of the tools needed for the particular type of work. It isuseful to keep a copy of the list in the van (or toolbox) so that a check can be madebefore leaving for site. If a tool is removed from the van, this can be noted on the list sothat it can be replaced or retrieved before attending site.

Operatives should ensure that, in situations where risks to health and safety cannot beadequately controlled by other means, they wear appropriate personal protectiveequipment (PPE) on site and when carrying out diamond drilling, sawing, and relatedwork. Appropriate PPE is mandatory and is designed to reduce risks and hazards to theoperator. It is required to be worn on all construction sites. Daily checks should becarried out on PPE before work commences and items replaced if necessary. Thefollowing list gives the PPE that is likely to be needed. All items may not be used on anyone job, but they should all be available as the need arises:

• overalls – worn to protect against dirt, abrasions and contaminants

• waterproof rain suit – worn to protect the body from the elements and also fromdirt, abrasions and contaminants, such as concrete slurry and oils, which couldcause skin irritation

• high visibility waistcoat/jacket with built in reflective strips – worn to makeoperatives more visible, particularly in conditions of poor light

• waterproof gloves – worn to protect hands from cuts, abrasions and contaminants,such as concrete slurry and oils which could cause dermatitis

• face dust mask – worn to reduce inhalation of dust and toxic particles

• goggles/safety glasses – worn to prevent eye injury and suitable for the particularhazard, e.g. they must be impact-resistant where there is a risk of flying debris.They are compulsory when operating certain types of machinery

• hearing protectors/defenders – used to reduce noise levels when working withmachinery which generates high sound levels

• rubber boots with steel toe caps – worn in wet/muddy conditions to protect toesand feet

• site boots with steel toe caps – worn to reduce the risk of foot or ankle injuries

• safety helmet – used to reduce the likelihood of head injuries from falling objects.

Safety and general 2.1



In addition, a number of items may be required in respect of site safety procedures.These include:

• Health & Safety Executive approved first aid kit for each van

• accident book

• demarcation barriers

• demarcation tape

• traffic cones

• a serviceable dry powder fire extinguisher.

Safety and general 2.1


Riskassessment


Introduction

The following range of hand tools is widely used in the drilling and sawing industry.In practice, the design of individual tools will differ slightly depending on themanufacturer and model. In addition to the tools specifically required for drilling andsawing, various general tools will be required for carrying out particular tasks.

Hand tools 2.2


Spirit levelUsed to check levels andverticals when setting upequipment. Normally made fromaluminium or glass reinforcedplastic (GRP). Available in avariety of sizes although thestandard 300mm length level isgenerally most useful.

Measuring tapeUsed for measuring distances.Length 3 metres and upwards.Normally incorporates a beltclip and tape lock.

Wire brushUsed for cleaning equipment.Brush has a wood handleand steel bristles.

Rubber or copper malletUsed for hammering sensitiveobjects that may be damagedwith the use of a metal hammer.Wooden shaft with a rubber orcopper head.

Lump hammerUsed for striking objects whereconsiderable force is required.The hammer has a metalhead and wooden orGRP shaft.

PliersUsed for cutting and crimpingmaterials, e.g. wire. Metal bodywith anti-slip handles.


Hand tools 2.2


SpannersUsed for tightening/undoingnuts and bolts.

Stilsons/Adjustable spannerMainly used on pipe work fortightening and looseningconnectors.

Allen keysUsed for tightening and undoingAllen bolts.

ScrewdriverUsed for tightening/undoingscrews. Normally supplied witha plastic handle and steel shaft.Available with a Phillips orPozidriv tip for cross headscrews, or parallel tip for slottedscrews.

HacksawHand held saw used for cuttingmetal, plastics or wood.

Cutting knifeUsed for cutting thin materialssuch as plastics, polystyreneand polythene. Metal or plasticconstruction and normally fittedwith a retractable, replaceableblade.


Specialist tools and accessories 2.3


Introduction

The following range of specialist tools and accessories is widely used in the diamonddrilling and sawing industry. A wide variety of diamond impregnated, segmented tools arerequired to carry out the cutting process. These are manufactured by mixing either naturalor synthetic diamonds with metals, followed by heating and pressing to form the segment.The segments are bonded to the cutting tool body by means of brazing or laser welding.

Floor sawUsed to form saw cuts in asphaltand concrete.

Track/wall sawUsed to form saw cuts inmasonry and concrete.

Specialist tools

Hand held sawUsed to form saw cuts inmasonry and concrete.

Diamond drillUsed to formholes inmasonryand concrete.




Concrete bursterUsed in conjunction with drilledholes to burst/fracture concrete.

Wire sawUsed to make saw cuts inmasonry and concrete structures.

Concrete crusherUsed to remove concrete bycrushing into manageable pieces.

Work EquipmentRegulations


Accessories

Diamond bladesUsed for the sawing, grooving orgrinding of masonry, stone,concrete and similar materials.The blade is essentially a circularsteel disc with diamondimpregnated metal rim.The material is compressed(deformed) by applying pressureby rollers to the inner and outerareas of the blade disc. Tensionis achieved by increasing thepressure applied by the rollers.

Care must be taken to ensurecorrect direction of rotationwhen fitting the blade. If a bladeis fitted the wrong way round it

Blades typically have asandwich construction whichoffers a number of advantages.

• The full segment height canbe used.

• The width of the segmentremains almost constant.

• The slight concavity helpsto guide the blade.



The saw blade dimensions areas follows:

Key

D = diameter

T = segment width

X = segment height

H = mounting hole

DT = pitch circle/drivehole

will not be irreparably damagedbut initial cutting will beimpaired and the blade will wearmore quickly.

Sandwich Non-sandwichconstruction construction

Manual handling


Diamond core bitUsed when drilling concreteproducts. Diamond segmentsare fitted onto the core barrel.

Diamond wireUsed when sawing into concreteproducts. Diamond segmentsare fitted onto the steel wire.

Diamond chainUsed for sawing concreteproducts. Diamond segmentsare fitted onto the chain sawblade.

Extension barThe bars are fitted between themotor shaft and the core barrelin order to extend the cuttinglength.

Abrasive productsBlocks used to sharpen diamondsegments; discs/blades forcutting steel reinforcement.

Diamond tipped bladeUsed for cutting masonry andconcrete products.






Vacuum pumpUsed for anchoring drill rigs onto solid surfaces, when drillingsmall diameter cores. This isachieved by using a rubbersealed pad, to which the volumeof air is removed in order toprovide suction, thus securingthe pad to the surface. The rigbase can then be attached tothe pad. Certain models of drillrigs have in-built vacuum pads.

AdaptorsUsed for connecting core bits,with different thread types, todrill motor shafts.

Steel wedgesShallow tapered steel sectionused to temporarily secureconcrete sections.

Crimping toolUsed as an aid to fix twosections of wire saw together.


Power supply and power tools 2.4


Introduction

Appropriate power supply equipment is required on site to enable power tools to beused safely and effectively. Power units are a vital piece of plant which provide thenecessary power to ancillary tools and equipment, such as wall saw heads, burster headand crusher jaws. These power units are specially designed to pump hydraulic fluid orprovide electricity to plant heads. Listed below are the items ofsupply equipment, power units and the common range of powertools used on site.

Power supply equipment

GeneratorUsed to generate electricalpower on site where no mainselectricity is available, to avoidlong runs of electricity supplycable or just for greaterconvenience. Normally petrol ordiesel driven, 16 or 32 amp andwith a 110V or 240V output.Rating varies from 2.4kVa up to7kVa.

Portable transformerUsed to reduce the mainssupply from 240V downto 110V in order to power110V power tools.Typically 3 – 10kVa(10kVa transformers aregenerally used onconstruction sites)and fitted with 16 and32 amp outputs.

Electrical safety

Extension lead and junctionboxesUsed to supply power fromtransformers to machinery.Available for 16 and 32 amp use.

Three-phase power unit orpetrol engineThree-phase power unit ispowered by electricity, generally415 volts, and rated 16, 32 or 63amps to suit tool requirements.

Petrol engine


Hydraulic power unitProduces a flow of hydraulic oilin order operate hydraulicpower tools.

Hydraulic hoses and couplingsReinforced rubber hoses thatcarry fluids at high pressure.Couplings seal and connect thefluid to operating parts of themachinery.

Power supply and power tools 2.4


Power toolsRotary percussive drill and bit.Used for drilling or breaking.The hole diameter for drilling isnormally up to 35mm. Pointsand chisels are available toassist with breaking.

Angle grinderUsed for cutting and grinding ofmetal, concrete and masonry.Can be fitted with an abrasivewheel or diamond blade.Generally used for cuttingreinforcement bars and theshallow cutting of masonrymaterials.

Note: Refer to Notes to trainers,5. Provision and Use of WorkEquipment Regulations,regarding competencerequirements for mounting andusing abrasive wheels.


Drip trayMetal or plastic tray, placedunderneath petrol/dieselpowered machines, to containleaks or spillages.

Water pumpUsed to clear water, ranging inextent from small spillages toflooding. Generally employed inthe drilling and sawing industryto remove excess water andslurries. Also used to pump waterto drilling and sawing equipmentthat requires water either as acoolant or for dust suppression.

Equipment and plant 2.5


Introduction

Equipment and plant, when used correctly, enables work to be carried out with greaterefficiency. Listed below is the common range of site equipment and plant used by adiamond drilling or saw cutting operative.

Wet and dry vacuum cleanerUsed for both dry and wetapplications. Dry use for theremoval of dust and wasteparticles; wet use for the removalof slurries or surplus water.

Tru-meterUsed for measuringdistances, mainly infloor sawing contracts.


Pressurised water tankUsed to provide water for drillcores. Supplied as anattachment for drills when usinga diamond core bit.

Equipment and plant 2.5


Ratchet strapUsed for securing loads, e.g. tovehicles. Also used for securinga drill stand to a suitablesupport. Comprises webbing,hooks and ratchet.

TrailerUsed for transportingmaterials, plant andequipment. Available insizes to suit the loadcarrying capacityrequired and designedto be towed behind avehicle.


Access equipment

Telescopic propsMetal props used to supportstructures and to stopcores/debris from falling.Available in lengths to suit.

Scaffold support systemScaffold system with flooringarea, used to provide totalsupport for the section of concreteto be removed. Normally used forthe removal of large floor areas.

Access equipment, barriers and signage 2.6


Introduction

The contractor must ensure that suitable access equipment is provided when working atheight. Barriers, protective sheeting and supports must be put in place to restrict entry inorder to protect site personnel and the general public. Appropriate signage must beused to convey safety notices and access information.

Mobile towerUsed as a temporary flooringsystem to allow safe working atheight. Be aware that thelightweight nature of aluminiumtower scaffolds may restrict theirusefulness in that:

• the maximum design load mayprohibit the positioning ofheavier items of equipment onthe working platform

• the lateral forces imposed atthe top of the tower by someactivities may make it anunsuitable means of accessfor the job, or require thatoutriggers are fitted.

Safe workingat height


Mobile Elevating WorkPlatform (MEWP)Commonly referred to as ascissor lift. Used when workingat variable heights.

Barriers

Temporary barrierUsed for demarcation purposesto keep non-authorisedpersonnel away from unsafeareas on site. Variousdesigns/systems are available.Often used in conjunction withcones and plastic tape.

Signage

Site safety signsExamples include signs informingthat noise generated by drillingand sawing equipment may

Access equipment, barriers and signage 2.6


Polythene screens ('Zipwall')Used to contain debris anddust. Zipwall system uses twocomponents: polythene, tokeep the area enclosed; andsupporting poles to securelyhold the polythene in place.

require ear protection to beworn, and signs warning of thedangers of overhead working.


Introduction

Good work practice, such as proper usage and maintaining tools and equipment in goodcondition, is an essential part of an operative's life. It helps to provide safe working forthe user and others.

Hand tools

Good quality hand tools are expensive to buy and unless properly maintained will needto be replaced frequently, resulting in extra cost to the operative.

It is difficult to achieve a good standard of work using dirty or blunt tools.

Hand tools stored with a protective film of oil should be cleaned with a dry cloth before use.

Care and maintenance

Only use hand tools for the purpose for which they are designed. Hand tools aremanufactured for specific applications. Using them for other purposes may shorten theirlife and result in damage or unsafe conditions.

Hand tools should be:

• handled with respect and not misused • kept in good order

• kept clean while being used • periodically inspected for defects.

• thoroughly cleaned after use

Remember: Tools should have their cutting edges inspected for damage at regularintervals; worn cutting edges/teeth should be sharpened or the tools replaced; damagedcutting tools blades should be replaced; saw blades should be replaced when teeth areworn; spirit and laser levels should be handled carefully and regularly checked for accuracy.

Storage

Always ensure that:

• hand tools are stored in tool bags/boxes for protection, safety and security

• hand tools are oiled to protect from rust (if not in continuous use)

• cutting knives are wrapped in a protective cloth (if blades are not retractable)

• saw teeth are protected by a plastic or timber saw guard

• sharp edges of tools, e.g. chisel tips, are protected by a plastic cap.

Diamond drills, saws and related equipmentRequire regular maintenance (and servicing) to ensure:

• safe working – poor maintenance can result in serious accidents

• maximum efficiency in use – good results without breakdown are only achievedwhen equipment is properly maintained and serviced

• PAT tests are up to date (test at least every three months and more frequently ifsubjected to harsh conditions or handling).

Maintenance of tool sand equipment 2.7



Diamond drills, saws and related equipment is very expensive and poor maintenance willresult in extra cost being incurred. Equipment must always be used within its capabilitiesand in accordance with the manufacturer's instructions. It must be handled and movedwith care.

Care and maintenance

• Clean after each job using water and detergent.

• Lubricate working parts according to the manufacturer's recommendations.

• Check oil, fuel and water levels (as appropriate) before use.

• Keep ventilation grilles clear.

• Regularly check the condition of cables, leads and connections, and replaceimmediately where necessary, referring to the manufacturer's list of power tool suppliers.

• Keep batteries fully charged.

• Replace batteries according to the manufacturer's guidelines.

• Always check the voltage of mains powered equipment before use. Use 110 volttransformers or, if equipment is 240 volt (e.g. a charging unit), a residual currentcircuit device (RCCD) should be included.

• Regularly check bolts and moving parts, e.g. sliding blocks.

• Regularly check saw blades – it is essential that saws cut true and that the bladeis sharp (replace parts once they become worn or damaged).

• In winter, ensure any water pipes and hoses are clear of surplus water to preventfreezing.

• Periodically check the tension of belts and adjust if required.

• Protect guide rails when not in use.

• Clean piston surfaces by extending pistons and wiping with an oily cloth.

Note: Ensure that guards are in place and fully functioning before operating power tools,and that dust or slurry collection is fitted (where supplied). Always disconnectequipment from the power source before changing accessories, servicing orperforming maintenance procedures. Checks, maintenance and servicing shouldbe carried out at the frequency (intervals) recommended by the manufacturer.

Storage

Portable power tools should be stored safely after use in the cases provided or insuitable containers or cupboards..

Personal protection

Use the appropriate personal protective equipment, e.g. goggles, masks, gloves, safetyboots, safety helmet, high visibility vest and ear defenders. Check regularly to ensureequipment is in good condition. Refer to Notes to trainers, 5. Provision and Use ofWork Equipment Regulations, with regard to the selection and limitations of PPE and RPE.

Maintenance of tools and equipment 2.7



Introduction

When used correctly, portable power tools enable the work to be carried out:

• with less effort

• more quickly

• with greater accuracy.

Power is from either:

• mains electricity – the principal source for many years, or

• rechargeable battery – now increasingly being used.

There are advantages and disadvantages with each type of power tool.

Mains supply versus battery operated tools

Reduced voltage supply using a transformer

110 volt portable power tools should be used on site for safety reasons. The use of thislower voltage supply reduces the effects of an electric shock. A work station is requiredwhen using such an electricity supply.

Power sources for portable power tools 2.8


Mains supply

Advantages Mains electricity provides constant supplyMore powerful

Disadvantages Requires mains power sourceRequires transformer if using 110V toolsTrailing cables/leads create a safety hazardPotential for serious or fatal electric shockRequires the availability of a residual currentcircuit device (RCCD)

Battery operated (cordless)

Advantages No trailing cables/leads to restrict movementCan be used instantly without setting up supplySafer to use because of the lower voltage atwhich they operate

Disadvantages Battery requires recharging and checks carriedout to ensure batteries are at full working power

Electricalsafety


Mains powered 110 volt work station

Where mains operated (240 volt) toolsare in use on site, all possibleprecautions must be taken to avoid therisk of injury due to electric shock. Aportable residual current circuit device(RCCD) such as a ‘Powerbreaker’ mustbe used. Its operation should be testeddaily, using the ‘test’ button.

110 volt tools must be used, and a workstation set up, using a transformer asshown in the illustration. The transformerreduces the mains power from 240 voltsto 110 volts.

Note: Any voltage above 110 volts ismore likely to cause injury in theevent of an electric shock.Tools working on 110 volts areconsidered to be relatively safeprovided they are correctlymaintained and are only operatedby operatives who have beenproperly trained in their use.

Power supply

Plugs for use with 110 volt supply

These must comply with British Standard BS EN 60309-2:1992.This standard is designed to prevent 110 volt tools being plugged into a240 volt supply, or vice versa. The plug and cable are identified by colourand the plug shaped so that it will fit only a socket designed for the samevoltage. Equipment for use on a 110 volt supply will have a yellow plugand usually the casing or supply cable will also be yellow.

Electric power tools

These must comply with British Standard BS EN 50144-2-1.

Battery operated (cordless) tools

These are referred to as cordless portable power tools because there is no trailing cableor lead. Two batteries are normally required:

• one in use on the power tool

• the other on charge.



110V plug yellow

Angle grinder

Cable 110V yellow

Plug withrecessed pins

Socket

Cable 240V blue

Three-pin plug formains socket


The charging unit is powered by mains electricity (240 volts) and should include anRCCD (residual current circuit device) in the power supply.

Note:Batteries are available to supply various voltages and power life (capacity).Details are printed on the battery and the manufacturer's instructions must befollowed. It is the responsibility of the user to ensure that the batteries are fullycharged and operational.




Section 3 Materials and components 3.0

44Section 3 Materials and components© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




3.1 Diamond blades 46

3.2 Other diamond products 50

3.3 Materials that are cut by diamond tools 51


3.1. List the four main components of a diamond blade.

Explain why it is important to make the right choice of diamond blade.

List the main factors that influence the choice of diamond blade.

Briefly describe a diamond chain, diamond wire and diamond core.

3.2 List the main types of diamond segmented tool.

List the typical materials which are cut using diamond tools.

State why hardness of the material to be cut is important.

State the name given to the scale which is normally used to measure hardness.

Explain why concrete containing steel reinforcement is more expensive to cut.

3.3 List the typical range of construction materials that are cut using diamond tools.




Introduction

A diamond blade comprises diamond crystals (also known as diamond grit or 'diamonds'),a bonding system/matrix, segments and a steel core. Each component has an importantfunction in the cutting process.

Diamond crystals

Diamonds are incredibly hard materials – it is the diamond crystals that achieve the cut.Diamonds used in the blades of diamond segmented tools conform to various grit sizesand grades. The size and grade used will depend on the application.

Bonding system/matrix

A metal bonding matrix holds the diamond crystals in place. Metal powders such ascobalt, iron, nickel, tungsten and bronze are used in combination. The bonding matrixplays a number of vital roles:

• disperses and supports the diamonds

• provides controlled wear while allowing diamond protrusion

• prevents diamond pull-out

• acts as a heat sink

• distributes impact and load as the diamond crystals grind the cutting surface.

In the cutting process, it is the diamonds in the metal bond that grind the material.This grinding process produces the cut and, at the same time, the material wears themetal bond, which exposes diamonds to the surface, refreshing the blade and extendingits useful life.

Segments

The mixture of diamond crystals and bonding metal powders is hot pressed intosegments. These segments are wider than the core to provide clearance during cutting.Segments are specifically designed to wear at a rate appropriate to the aggregate beingcut. Diamond concentration in the segment can vary from low to very high, dependingon specific requirements, e.g. lower power saws generally require low concentrationblades for best overall performance; high power saws generally require high concentrationblades for best overall performance.

Steel core

The segments are attached to a premium steel alloy core. This core is a precision madesteel disc which incorporates slots. The slots, often referred to as 'gullets', provide fastercooling by allowing water or air to flow between the segments.

Diamond blades 3.1



Most blade cores are factory tensioned to ensure that the bladeruns straight at cutting speed. Sufficient tension allows theblade to remain flexible enough to bend slightly under cuttingpressure and snap back into position. An arbor hole is preciselybored in the centre.

How do diamond blades work?

Diamond blades do not cut in the same way as a knife. They work by grinding into thematerial. During the manufacturing process, individual diamond crystals are exposed onthe outside edge and sides of the diamond segments (or rim). It is these exposeddiamonds that do the actual grinding.

It is the metal bond which locks each diamond in place. Trailing behind each exposeddiamond is a 'bond tail' which helps support the diamond.

As the blade rotates on the arbor shaft of the saw, the operator pushes the blade intothe material. The blade begins to grind through the material, and at the same time thematerial starts wearing away the blade. Exposed surface diamonds score the material,grinding it into a fine powder. The embedded diamonds remain beneath the surface.Exposed diamonds crack or fracture as they cut, breaking down into even smallerpieces. Hard, dense materials cause the diamonds to fracture even faster.

The metal bond also begins to wear, allowing new layers of diamond to be exposed toallow cutting to continue. This process continues until the blade is worn out, althoughsometimes a small, unusable part of the segments or rim may remain.

It is important to understand that the diamond blade and the material to be cut mustwork together for the blade to work effectively. Also, the diamond type, quality, grit size,and the metal matrix used, must be suited to the saw and the material to be cut.

Choosing the right diamond blade

Diamond blades are available to fit all saw types, e.g. masonry saw, floor saw, highspeed saw, angle grinder, floor grinder. The choice of blade depends on a number offactors. These include:

• the power rating of the saw and maximum safe speed

• the material to be cut

• whether the cutting will be wet or dry

1. The power rating of the saw

Manufacturers of diamond blades design products to run at specific speeds.

The table overleaf gives typical operating speeds for best performance and the maximumsafe speed.

Diamond blades 3.1


Effective guardingof blades


Note: The diamond blade cutting depths listed in the table are approximate. The actualcutting depth will vary with the exact blade diameter or saw type/model, and theexact diameter of the blade collar (flanges). The cutting depth will be reduced ifsaw components – e.g. motor housing, blade guard – extend below the blade collar.

2. The material to be cut

Correctly identifying the nature of the material to be cut is the most important factor inchoosing a blade. The choice directly affects the cutting speed and the life of the blade.

Materials will generally be hard, e.g. granite or a Class A engineering brick, or medium/hard,e.g. a concrete-based building material. Materials can also be abrasive (or extremelyabrasive) depending on the nature and the presence of any aggregate or additives.

When cutting hard materials, choose a blade with a softer bond. This type of blade willrelease diamond grit at the point of maximum utilisation, without the danger of the bondholding the grit too long so that the blade overheats at the cutting point. If this happens,segments will overheat and glaze over. The glazed surface will curtail the grindingprocess because there will be no new diamonds being exposed at the cutting edge.The diamond blade will have to be re-dressed (sharpened) before further use.

If soft materials are to be cut, select a harder bond that will hold the diamond grit longerand make it more productive. If you use a soft bond to cut soft material, the bond willrelease the diamonds before they have reached maximum utilisation and good diamondswill be lost prematurely. The blade will still cut adequately but productivity will be poor.

Most diamond blades cut a range of materials. However, the material should be matchedto the blade as closely as possible. As a general rule, determine the material that will be

Diamond blades 3.1


Diameter Cutting depth Recommended Maximumoperating speed safe speed

Inches mm mm RPM RPM

4 100 25 9075 150004.5 115 30 8065 133005 125 40 7250 120007 178 65 5175 87258 200 75 5180 87309 230 83 4540 764012 300 100 3024 630014 350 117 2592 436516 400 143 2268 382018 450 168 2016 336520 500 194 1814 305524 600 244 1512 250026 660 270 1396 235030 760 300 1120 204036 910 375 1008 1700


most frequently cut (or the material for which blade performance is most important) andthen select the most appropriate blade type.

3. Wet or dry cutting (refer to Section 4, Hand sawing)

The choice of wet or dry cutting can be down to the job requirement but is often a matterof user preference.

When using a hand power tool, such as an angle grinder, it is not safe to use waterbecause of the electrical power source. With floor saws, wet cutting is normallypreferred because a deeper cut can be achieved when using water as the coolant.For tile and masonry saws, either wet or dry cutting can be used. For hand held petrolsaws, dry blades are more popular, but they are often used wet to facilitate dust control.

Wet blades MUST be used with water. Dry blades may be used either dry or wet as thejob or equipment allows.

4. Other factors that can affect performance

Many other factors affect the blade's performance and life. These include the diamondsize, concentration and quality; the hardness of the bond; and how well the bladespecification is matched to the material being cut. The table below gives some generalguidance.

Diamond blades 3.1


Variables Condition Cutting speed Blade life

Bond hardness Harder Slower LongerSofter Faster Shorter

Diamond quality Lower Slower ShorterHigher Faster Longer

Diamond grit size Coarser Faster LongerFiner Slower Shorter

Diamond concentration Lower Faster ShorterHigher Slower Longer

Horsepower Lower Slower LongerHigher Faster Shorter

Blade RPM Lower Faster ShorterHigher Slower Longer

Water flow Lower Faster ShorterHigher Slower Longer

Cutting depth Shallow Faster LongerDeep Slower Shorter

Material hardness Harder Slower LongerSofter Faster Shorter

Aggregate size Larger Slower ShorterSmaller Faster Longer

Steel reinforcement Less Faster LongerMore Slower Shorter


Diamond chain

The chain is made up of links. The cutting link has a diamond tipped segment that islaser welded to the link.

Diamond wire

This is high breaking strength steel wire which acts as a carrier for the diamond crystals.These are sintered or electroplated, much like segments on saw or drill bits. They arefitted onto the wire and are generally spaced, using spring spacers, to reduce the risk ofdamage to the diamonds (disarrangement). The wire is also sleeved with plastic or rubberto prevent corrosion. The wire length will depend on cutting requirements. The wire endsare linked by joint connectors and crimped together using a hydraulic hand press.

Diamond core bit

Diamond core drilling of reinforced concrete is both an art and a discipline. It requirespatience, structural appreciation, a mechanical aptitude and considerable fitness.

The basics for successful core drilling are having a rigidly set up drill rig, diamond corebits with adequate clearances on the outside and inside diameters, a constant waterflow, and the right speed range and power for the bit.

The core drill bit consists of a steel tube/barrel with diamond segments brazed orlaser-welded onto one end and a fixing thread on the other end which is connected tothe rotating shaft of a drill motor. The segment is produced in a similar way to thesegment of a blade.

Core drills are available in a number of diameters and lengths to suit. They are used to cutconcrete and masonry products in a variety of applications. In some applications the coredrills can be used dry whilst in others water is required as a coolant for the segments.

Other diamond products 3.2



A range of materials can be cut successfully by diamond tools, including concrete,aggregates, steel reinforcement, asphalt, masonry, brick and block, stone and ceramic tiles.

Concrete – general

When cutting concrete, several factors will influence the choice of diamond blade.These include the following:

• compressive strength

• steel reinforcing bar

• hardness of the aggregate

• whether the concrete is cured or 'green'

• size of aggregate

• abrasiveness of the aggregate

• type of sand.

The length of curing time after concrete is poured greatly affects the way the diamondblade will interact with it during cutting. Curing can be affected by weather(temperature, moisture and wind) and the composition (admixtures, aggregate and sand).

Green concrete

Concrete is typically in its green state for 6 to 48 hours after pouring. In this early state,the sand is not completely bonded with the mortar and the concrete has not reached itsfull hardness. When cutting green concrete, the sand loosens more readily and flowsmore freely in the slurry. This results in much greater abrasion on the diamond blade.

Undercut protection is critical when cutting green concrete to prevent excessive wear onthe steel core at the segment weld. Sawing green concrete is common when working onnew construction projects such as motorways, runways, driveways and industrial flooring.

Cured concrete

Cured concrete slabs will vary in compressive strength depending on factors such as thegrade of cement used, the grade/type of aggregate and the conditions during which curingtook place. The table below gives typical compressive strength values for concrete.

Materials that are cut by diamond tools 3.3


Concrete hardness Compressive strength (PSI) Typical application

Very hard 8,000 or more Nuclear plantsHard 6,000 – 8,000 Bridges, piersMedium 4,000 – 6,000 RoadsSoft 3,000 or less Pavements, patios

Eye and hearingprotection


Aggregates

Aggregates are the granular fillers in cement. They can occupy 60 – 75% of the totalvolume and can influence the way both green and cured concrete performs. Aggregatescan be naturally occurring minerals, e.g. sand and gravel, crushed stone or manufacturedsand. The most desirable aggregates for use in concrete are hard, dense and well-graded,triangular or square in shape, and with good durability. The average size and compositionof aggregates greatly influence the cutting characteristics and selection of the diamondblade.

Large aggregates tend to cause blades to cut slower whilst smaller aggregates allow theblade to cut faster.

Aggregate hardness is a very important factor when cutting concrete. Hard aggregatewill dull the diamond grit more quickly, therefore segment bonds generally need to besofter when cutting hard aggregate. This allows the segment to wear normally and bringnew sharp diamond grit to the surface. Softer aggregate will not fracture diamond grit asquickly, so harder segment bonds are needed to hold the diamond in place long enoughto utilise their full potential.

Most aggregates fall within the 2 to 9 range on the Mohs' hardness scale. Values ofhardness are assigned from 1 to 10. A substance with a higher Mohs' number willphysically scratch a substance with a lower Mohs' number. The higher the number, theharder the material. The scale below gives the Mohs' number for some common minerals.

Type of sand

Sand is part of the aggregate mix and determines the abrasiveness of concrete. It caneither be sharp (abrasive) or round (non-abrasive). To determine the sharpness of sand,its source needs to be known. Crushed and bank sand is usually sharp (abrasive); riversand is usually round (non-abrasive).

Steel reinforcement

Reinforcement is included in concrete to improve its strength and structural integrity.Types of reinforcement include steel bars ('Rebar'), steel wire strand or wire meshing.It costs more to cut concrete that contains reinforcing steel because cutting rates areslower and the blade life is reduced. If the cross-sectional area of concrete is 1% steel,



Mohs' range Description Aggregate

8–9 Very hard Flint, sea gravel, river gravel6–7 Hard Hard granite, quartz4–5 Medium/hard Medium hard granite3–4 Medium Dense limestone, sandstone, marble2–3 Medium/soft Soft limestone


the blade life will be about 25% shorter than if no steel were present. Concrete with 3%steel included can reduce blade life by as much as 75%.

Asphalt

Hot mix asphalt (HMA) is a mixture of asphalt concrete (a petroleum based 'glue' thatcomprises less than 8% by weight of the total pavement mixture), aggregates of varioussizes and sand. Asphalt does not cure as concrete does, and once spread and rolled, itcan be cut or drilled almost immediately. Unlike cured concrete, sand in asphalt neverbonds as firmly and the slurry created when sawing will be extremely abrasive.

A metal bond, similar to that required when cutting green concrete, together withundercut protection for the steel core, are important considerations when undertakingasphalt cutting operations.

It is common for many operators to cut through the asphalt layer into the sub-base.However, this should be discouraged as generally the sub-base contains high levels ofvery abrasive materials such as sand and dirt. Cutting the sub-base would thereforeresult in rapid wear of the diamond blade.

Brick and block

Generally concrete building blocks tend to be relatively soft and abrasive, whilst bricks tendto be harder and less abrasive. There is a large number of brick types on the market, eachdesigned and manufactured to provide specific characteristics. The degree or hardnessis largely determined by the clay mixture, method of manufacture and the firing temperature.

Stone

Natural stone can be hard or soft as the table below demonstrates.

Ceramic tile

Ceramic tile is typically on the higher range of the hardness scale although there aredifferences depending on the clay mixture, manufacturing process and firing temperature.A common concern when cutting tiles is chipping. For this reason, diamond blades withcontinuous rims, closely spaced segments or turbo segments are often popular choices.



Hard FlintGraniteSlateMarbleFlagstoneSandstone

Soft Limestone



Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




4.1 General 56

4.2 Ring sawing 58

4.3 Chain sawing 70

4.4 Angle grinding 74

4.5 Twin blade chasing 78

4.6 Do's and don'ts for the safe use of hand heldpower saws 81

Section 4 Hand sawing 4.0

54Section 4 Hand sawing© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


4.1 List the main types of hand held power saw used for cutting concrete and masonry.

4.2 List the typical applications for a ring saw.

Give a brief description of the ring saw.

List the periodic checks which should be made.

Explain the procedure for installing a new blade.

Explain the procedure for adjusting the roller.

Explain the procedure for making a saw cut.

4.3 List the typical applications for a chain saw.

Give a brief description of the chain saw.

Explain the procedure for adjusting the tension.

Explain the procedure for making a saw cut.

4.4 List the typical applications for an angle grinder.

Give a brief description of the angle grinder.

Explain the procedure for assembly.

Explain how to adjust the guard and grip.

Explain the procedure for cutting/grinding.

4.5 List the typical applications for a twin blade chaser.

Give a brief description of the twin blade chaser.

4.6 List some of do's and don'ts for safe operation of hand held power saws.




Introduction

A variety of hand held power saws are used by the drilling and sawing industry.Hand held power saws used in sawing contracts have a number of benefits overstandard track saws or drill rigs:

• better suited to the type of sawing work undertaken

• less time required for setting up.

Note: Using a hand held power saw introduces the likelihoodof the user being subjected to hand/arm vibration plushigh levels of noise and airborne dust due to the closeproximity of the user to the cutting disc.

The choice of hand held saw depends on the type and size ofcontract. The four machines identified in this section are thering saw, chain saw, angle grinder (also referred to a disccutter or 'chaser') and twin-blade chaser.

Ring saw

A hydraulic or petrol powered hand held unit which gives a cutting depth of 260mm froma 350mm diameter blade. This is achieved by a unique design where the blade is drivenfrom the periphery instead of the centre. It is generally used hand held but can also berail mounted. Pre-cuts can be made using an angle grinder or disc cutter, helping toensure cost-effective production and easier, safer results. Ring saws are fairly compactand do not take long to set up. For these reasons they are frequently used in contractswhere space is restricted and where the amount of cutting required is relatively low.

Chain saw

A development of the wood chain saw which can be either hydraulic or petrol powered.This type of saw uses a chain fitted with diamond segments. Chain saws are often usedfor cutting window/doorway openings in brick and blockwork. This is because straightlines can be cut with right-angled corners, eliminating the risk of over cutting. The sawscan be hand-held or mounted on a rail. Chain saws can be used to make cuts up to600mm deep.

Angle grinder

Angle grinders can be hydraulic, electric or air-driven. They are fitted with diamondtipped laser-welded blades. They normally run dry and can be fitted with an abrasivecutting/grinding disc for sawing stone or metal. They can also be used to cutreinforcement when crushing or bursting. Cutting is restricted to a depth of approximately150mm. Angle grinding is a very basic method of intermittent cutting to form ashallow cut into brick or concrete. It is effective in producing saw cuts in brick andnon-reinforced concrete, but will also cut through reinforced concrete.

General 4.1


Noise, vibrationand manualhandling

Protection ofthe airway, eyes

and skin


Twin-blade chaserThis is a purpose-built angle grinder. Two blades can be fitted to the shaft which makesit very effective when used to form chases in masonry for conduits and pipes.Application and cutting is the same as for the angle grinder.

General 4.1



Sawing applications

The ring saw is used for wet-cut applications. It is the ideal machine for cutting aperturesin walls and wherever there is a need for deep cuts in concrete, stone and cast iron withthe minimum preparation. Ring saws are used for cutting doors/window apertures andfor cutting apertures in cast floors and roof structures. They are also used for trimmingpre-fabricated concrete elements.

Description of the saw

The diamond blade in the ring saw is driven from the edge. This means that the bladecan cut almost as deep as its own diameter (the 350mm blade will allow a 260mm cut tobe made). Blades are generally supplied in four different grades.

The saw blade runs on, and is held in place, by four lateral rollers. Two of these, theguide rollers, engage in a groove on the side of the blade, pressing it forwards undertension and into the drive wheel. The drive wheel is powered by the hydraulic motor andhas a V-shaped groove which engages with theblade, driving it rather like a pulley drives aV-belt. The other two rollers, which arecalled backing rollers, hold the blade inplace from the other side. The saw canbe used with a rail attachment to assistthe operative.

The saw is connected to a suitable powerunit – either a 2-stoke motor or hydraulic unit.Typical specifications are as follows:

Ring sawing 4.2


Typical ring saw

2-stroke power source

Displacement: 93.6 cc

Power: 4.5/6.12 kW/Hp

Weight empty1: 13.1kg

Max off-load speed: 9,800 ± 300 rpm

Fuel tank capacity: 0.5 litres (approx)

Noise level: 103.5 dB(A)

Vibration level: m/s2

Front/rear (idle): 7.7/11.8

Front/rear (max speed): 2.8/7.5

Ring speed (max off-load): 55 m/s

Cutting depth: 260/10 mm/inch

Noise emission: 117 dB(A)1 Minus cutting ring


Components

The following items are the basic components to the ring saw.

Ring sawing 4.2


Hydraulic power source (in conjunction with power pack)

Hydraulic pressure (Max) 150 bar (2200 psi)

Oil flow (minimum-maximum) 35–42 litres/min

Weight (excluding blade) 7.9kg

Weight of cutting blade 0.8kg

Water requirements 4 litres/min

Stop-pinWhen changing the drivedisc, compress thestop-pin to lock the driveshaft.

Location of stop pin

Poly-V beltThe eight-ribbed beltprovides powertransmission anddurability (refer to themanufacturer'smaintenance instructionsfor re-tensioningguidelines).

V belt drive

Support roller armsThe roller arms areencased in hardened steelsleeves with O-ring sealsthat support the blade(refer to the manufacturer'smaintenance instructionsfor adjustmentguidelines).

Location of support roller arms


Guide/support rollers,engagement rollers anddrive discThe two roller shafts areshort and sturdy.Pressed-in, hard-chromedsleeves allow the rollershaft to move smoothlyin a well sealed area.

Each shaft has dual,sealed ball bearings toprovide the correct anglefor the guide ridge onthe roller to engage intothe groove of the blade.

The engagement rollersprings force the rollerout, pushing theV-shaped edge of theblades inner diameteragainst the V-shapedgroove of the drive disc.

The drive is mounteddirectly to the hydraulicmotor. The drive discrotates the ring bladefrom the inner edge ofthe blade (not from thecentre where the axlewould limit the cuttingdepth).

HandleThe front handle isadjustable to ensure thebest possible workingposition.

The rearmost position isa service position, foruse when removing thesupport roller casing.

Adjustable handle position

Ring sawing 4.2


Position of the guide rollers and drive disc

BladeSupport rollers

Drive Engagementdisc rollers

V-shaped wedge

Contact of rollers and drive disc with the blade


Ring sawing 4.2


Throttle/water controlThe throttle can be locked in placeby depressing the lockout trigger.A water on/off switch is built intothe trigger. The water flow can beadjusted during operation usingthe water adjustment valve whichis located above the lockout trigger.

Power unit and hydraulic hosesTypically 40, 30 and 20 litres/minflow rate; 12kW petrol engine and140 bar pressure. The weightincluding 9m hoses is around 88kg.

Flow meterTypically 40, 30 and 20 litres/minflow rate and operates at 140 barpressure. The weight is around4.2kg. Flow meters are used withan excavator or truck hydraulicsystem to control hydraulic flow tothe saw.

Periodic checks

Checking the blade and roller adjustment

As the saw blade is used, the blade inner diameter, as well as the groove in the drivedisc, will wear. The saw will continue to operate well if:

• the drive disc is not overly worn

• the engagement rollers are not overly worn

• the adjustment between the rollers and the blade is correct.


During the life of the blade, the roller adjustment needs to be checked twice: once afterblade installation and once when the blade has worn by 50%. Never try to re-tip a usedring blade. A used blade may not have the proper strength. A re-tipped blade may crackor break and cause severe personal injury to the operator or others.

Note: Always disconnect the ring saw from the hydraulic power source when makingperiodic checks or servicing. Unexpected blade rotation could cause severe injury.

Procedure for installing the blade

Fitting the blade

Ring sawing 4.2


Condition of drive disc Condition of engagement roller

Worn New

WornMin 1.5mm

New3mm

1. Wipe off any dirt from the surface ofthe blade.

2. Loosen the locking nuts on thesupport roller cover.

Competence


Ring sawing 4.2


5. Pull out the lock for the front handleand move the handle into theservice position.

6. Remove the three screws holdingthe support roller guard (depicted byarrows in the illustration) using a6mm hex key and lift off the cover.

3. Unscrew the adjuster screws a fewturns.

4. Loosen each knob to release thetension in the springs.


8. Press in the guide roller (if necessary)so that it climbs into the grove of theblade.

Ring sawing 4.2


7. Fit the blade (the blade has twogrooves on one side, depicted by theshort arrows in the illustration, that actas guide grooves for the guide rollers).Ensure that the V-shaped edge of theblade enters the drive wheel and thatthe blade's guide groove fits in theguide rollers.

9. Fit the support roller guard, ensuringthat the flanges on the guide rollersstill enter the blade grooves correctly,and fully tighten the three screws.

10. Rotate the blade, making sure thatthe support rollers are not clampedagainst it.


Ring sawing 4.2


Adjusting the support rollers

1. Turn the adjuster screws so that thesupport rollers make contact withthe blade.

2. Check that the support rollers canbe easily stopped using thumbpressure when the blade is rotated.The support rollers should onlyfollow the blade occasionally.Adjust if required.

3. Tighten the locking nuts on thesupport roller guard.

4. Rotate the blade, making sure that itis still possible to hold the rollerswith thumb pressure when the bladeis rotated. It is important that themachine is upright when makingchecks and adjustments. If themachine is on its side, the weight ofthe blade will make it difficult tomake a correct adjustment.


Ring sawing 4.2


5. Tighten the knobs fully. The machineis now ready to use.

Note: It is important that the adjustmentbetween the rollers and the bladeis correct. Too tight a setting willquickly damage the blade. Tooloose an adjustment may causethe blade to jump off theengagement rollers. The supportrollers do not drive the bladeand improper adjustment canlead to blade damage.If the blade turns slowly or stops,refer to the troubleshootingguidance in the manufacturer'sinstructions.


Connecting the hydraulic hoses

Never connect to hydraulics where the pressure generated is more than 150 bar (3000 psi)as serious injury can result. The following checks should be made before connectingthe hydraulics:

• make sure that the couplers are clean, both on the machine and on the hose set

• connect the first pressure hose (which exits the power pack), to the femalecoupler on the left-hand side of the ring saw

• connect the second hydraulic hose to the male coupler on the right-hand side ofthe ring saw. This hose is the oil return line to the reservoir

Note: Two sets of hoses may be connected to extend the distance between the powerpack and the saw. Do not connect more than two sets as a reduction in pressuremay result (power may be lost through the couplers). Refer to the manufacturer'sinstructions for guidance.

Always twist the safety locks into position on the couplers before operating the ring sawto prevent accidental disconnection.

Note: When the ring saw is in operation, the hoses will beunder extreme pressure. Do not attempt to connect ordisconnect hoses with the hydraulic power sourceoperating. To do so may cause serious injury.

Connecting the water hose

Connect the water hose to the water supply. Water flow is activated by the throttletrigger lockout. The minimum water requirement is 4 litres/minute (1 gallon/minute).

Procedure for cutting

Preparatory

1. Assess the suitability of the working area.

2. Set up the water and power requirements.

3. Work out the sequence of cuts.

4. Check the blade and fit new if worn or damaged.

5. Have cutting templates available (templates help in following the required cutting line).

Making the cut

1. Support the workpiece in such a way that the cut remains open during the cuttingoperation, thus avoiding 'pinching' (if the cut is pressed together, this can lead to theblade jamming in the cut, which will cause the machine to be pulled down suddenlywith a very powerful jerk).

Ring sawing 4.2


Competence


2. Before starting the machine, check that the blade is not in contact with anything.

3. Turn on the water supply.

4. Grip the machine firmly with both hands and start the saw.

5. Position the saw to the line of cut.

6. Start cutting smoothly, allowing the machine to work without forcing the blade.

7. Cut at maximum speed with the blade at a 90º angle.

8. Move the blade slowly backwards and forwards to give a small contact surfacebetween the blade and material to be cut. This will prevent the blade overheatingwith a resultant reduction in the cutting efficiency.

9. Working from the lowest point of the cut, sink the blade in 25–30mm approx. andfollow the line to the end. The depth of each pass will vary depending on thestrength of the material being cut.

10. At the end of the cut, apply pressure, take the blade another 30–50mm in, and followthe cut using the step method until achieving the depth required.

11. Turn off the power.

12. Remove the machine from the cut section.

13. Turn off the water and power.

Troubleshooting

Blade will not rotate

1. Roller handles not locked into position.

2. Blade not installed correctly (not engaging on to the guide rollers).

3. Faulty bearing on rollers.

4. Rollers adjusted too tightly.

5. Incorrect hose connection to power pack (or other hydraulic problem).

Blade turning too slowly

1. Roller handles not locked into position.

2. Drive disc worn.

3. Inner edge of blade worn.

4. Springs on engagement rollers weakened.

5. Dirty pressure relief valve in power pack.

6. Valve lever on hydraulic motor not travelling the full distance.

7. Faulty roller bearings.

8. Insufficient oil flow (check hydraulic oil flow).

Ring sawing 4.2



Blade jumping

1. Roller adjustment too loose.

2. Worn engagement rollers.

3. Blade not installed correctly (not engaging on to the guide rollers).

4. Damaged blade.

Blade warping in use

1. Rollers adjusted too tightly.

2. Blade overheating.

Segment loss

1. Blade bent, twisted, or mishandled.

2. Poor weld (continue to use the blade if only one segment is lost; have it re-tipped ifthe blade is worn by less than 50%).

Motor seal blown

1. Saw running backwards (check the hydraulic hose connections on non-partnerpower pack. Check position of control valve on non-partner power pack).

2. Excessive hydraulic flow or pressure.

3. Faulty seal.

Blade cutting too slowly

1. Wrong blade for the material being cut.

2. Inadequate water supply (check supply to the blade).

Blade slipping

1. Engagement roller not moving freely in and out (a stuck roller cannot push the bladehard enough against the drive disc).

2. Drive disc worn (abrasive materials and poor flushing will wear the disc more quickly)

3. Shoulder of the guide roller is more than 50% worn.

4. Blade tracking groove and inner edge worn (caused by poor flushing of the abrasivematerial and/or a worn drive disc).

Ring sawing 4.2



Sawing applications

Chain sawing is an alternative to track sawing. The chain saw is a versatile tool which isideal in situations where an extreme cutting depth is required. It can be used for cuttingsquare corners, irregular shapes, and openings down to 110mm square.

Description of the saw

The saw is powered either byhydraulics or by a petrol engine.The depth of cut is determined bythe position of the bar, with themaximum depth being 600mm(it can cut 560mm without overcutting). The maximum cut heightis 110mm. Hydraulic poweredsaws are attached to a separatepower unit that can be diesel,petrol or electric. An optional railattachment can be used to assistcutting. Chain saws are used forwet cutting only.

Typical specification for the petrolengine is shown below.

Chain sawing 4.3


2-stroke power source

Displacement: 93.6 cc

Power: 4.5/6.12 kW/Hp

Weight empty1: 9.4 kg

Max off-load speed: 9,800 ± 300 rpm

Fuel tank capacity: 0.5 litres (approx)

Noise emission: 116 dB(A)

Noise level: 103 dB(A)

Vibration level: m/s2

Front/rear (idle): 10.8/12.1

Front/rear (max speed): 2.2/8.7

Chain speed (max off-load): 28 m/s

Cutting depth: 390/15 mm/inch1 Minus cutting bar and chain


Components

The following items are the basic components of the chain saw.

Diamond chain

The chain design is made up of links. Each cuttinglink has a diamond tipped segment that is laserwelded from two directions for durability.A 350mm (14 inch) bar chain has 32 diamondtipped segments. The segments are 7mm wide, asopposed to a conventional segment dimension fora cutter blade of 4.5mm. A link with the guard infront of the diamond segment serves as a depthlimiter and thus protects the segment fromoverloading and also from impact. Impact protectionis important when the saw is working at the tip ofthe bar, when only a few diamond segments are incontact with the material at any one time.

The chain width is normally 0.225 – 0.227mmalthough wider chains can be used, e.g. 0.230mmor greater, to avoid the risk of the chain ‘pinching’when other machines are being used.

When fitting a new chain, place it around thesprocket and blade sword, in accordance with themanufacturer's instructions.

The chain has drive links which fit in the drivesprocket. Their purpose is to power the saw andcontrol the position of the chain on the bar.

Chain sawing 4.3


Chain saw links

Chain fitting

Position of drive links


5. Push the lever forward. Thistightens the bar nut to keep the chaintensioned.

Pushing the lever forwards to maintainthe tension

6. Tighten the holding screw to 'lock'the chain tension.

Tightening the holding screw

7. Close the cover over the holdingscrew. The cover keeps dirt outand also secures the holding screw.

Cover closed

Chain sawing 4.3


Tensioning lever

This allows the chain tension to be adjusted. To adjust the tension, follow theprocedure below.

1. Open the rubber retainer over theholding screw.

2. Unfold the handle on the tensionlever.

Adjusting the tension

3. Push the lever back and down.This loosens the bar nut and tensionsthe chain.

Pushing the lever back and down

4. Lift the bar at the tip.

Lifting the bar

Note: Unlike other hand held saws, the chain saw has no 'gyro' effect.


Counter hold/wear protector

By pressing the rubber support against the object, the operator can create a lever effectwhich increases the feed pressure.

Other components

Additional components include the following:

• bar

• counter hold screw

• hand guard

• splash guard

• water connection and quick release coupling

• water valve.

Procedure for cutting

The basic technique is to move the machine backwards and forwards along the cutwhilst maintaining an even application pressure.

1. Make an incision to the full cutting depth.

Note: When applying the tip of the bar to the object being cut, the lower section of thechain nose should be used. If the upper part is used there is a risk of throw-back.That is to say, the chain 'climbs' up the object and the bar is thrown up andbackwards towards the operator.

2. Allow the machine to perform a slow swinging (pendulum) motion while cutting.If the contact surface between the chain and the object is kept 'short', the work willproceed more quickly.

3. When using the chain saw in combination with a cutting tool that produces anarrower slit, use the chain saw first.

Note: An incision made with a chain saw in a previously made narrower cut willresult in the chain getting stuck and a risk of throw-back. The chain will beover-loaded and broken diamond segments or chain breakage will result.

Chain sawing 4.3



Cutting/grinding applications

Angle grinders are used for shallow cutting or grinding. Cuts can range from 75mmto 400mm.

Description of the grinder

The abrasive disc can be fitment or diamondimpregnated. Angle grinders are electrical,hydraulic or pneumatic-powered. A safety switchis incorporated which prevents the grinder fromstarting should the on/off switch be pressed inerror. Angle grinders are single bladed withone exception. The chasing machine is twinbladed which facilitates the removal of widersections of material, e.g. when 'chasing' incable runs and pipe work. Angle grinders aregenerally used for dry cutting.

Components

The following items are the basic components of the angle grinder:

• motor body

• blade guard

• body handle

• blade flanges

• power lead.

Assembly and adjustment

Fitting the blade and guard.

1. Place the guard over the central spindle so thatit seats onto the plastic flange.

2. Place the clamping washer over the spindleand align the holes (three small and one large)with the screw holes in the grinder head.

3. Insert the three screws through the small clampwasher holes, and tighten.

4. Place the washer over the bolt and screw intothe large clamping washer hole, using aspanner, but DO NOT tighten.

Removing the guard

Angle grinding 4.4


Typical angle grinder


Fitting the grinding disc

1. Lay the grinder on its back and place the disc flange on the centre spindle, ensuringthe joint ring is facing upwards.

2. Bed the disc flange onto the spindle housing.

3. Position the grinding disc on the spindle.

Disc, spindle and housing

4. Screw the disc securing ring with the flange facing in (if the disc is more than 5mmthick) or facing out (if the disc is less than 5mm thick).

Alternative orientations for the disc locking (securing) ring

5. Stop the spindle from turning by pushing in and holding the stop button.

6. Lock the grinding disc into place by tightening the disc securing ring using apin wrench.

7. When complete, release the locking button and check that it has sprung back to itsinitial position.

Note: Disc fitting should only be performed by a person holding a grindingwheels certificate.

Angle grinding 4.4


Greaterthan 5mm

Disc lock ring flange inward Disc lock ring flange outward

Lessthan 5mm


Adjusting the guard and grip

1. Position the guard to allow maximum working performance whilst providing maximumpersonal protection for the operator.

2. Lock the guard in place by tightening the locking nut using a spanner.

Locking the guard

3. The hand grip gives better control and safety. Fit by screwing into the left, right ortop body head, as appropriate.

Position of hand grip

Procedure for cutting/grinding

1. Ensure that the disc safety guard is in place and that appropriate PPE is being worn.

2. Connect the grinder to the power supply (and to the dry vacuum if appropriate).

3. Ensure that the correct blade/disc is fitted for the material to be cut.

Angle grinding 4.4



4. Ensure that the material to be cut will be stable when cutting.

5. Start the grinder by depressing the safety switch and depressing the on/offswitch (trigger).

Note: When the grinder first starts it will kick to the right. Operatives must ensure,therefore, that the tool is securely gripped in both hands to maintain stability.

6. For continuous running, press the safety switch and trigger. Let go of the triggerwhilst continuing to hold down the safety switch, then release the safety switch.The grinder will continue to operate until the on/off trigger is pressed again.

7. Allow the disc to reach its full operating speed.

8. Gently make contact with the surface of the material to be cut.

9. Apply the step method of shallow passes to achieve the required depth.

10. Switch off the grinder by releasing the on/off trigger. The machine will stop and thesafety switch will reset itself.

Note: Laser welded blades are for shallow intermittent cutting in a forward motion only.Abrasive discs can cut in both a forward and reverse direction.

Angle grinding 4.4


Hazardous dust,noise andvibration


Cutting/grinding applications

Twin blade chasers are used for shallow cutting or grinding. The twin blades make it veryeffective when cutting chases in masonry for conduits and pipes.

Description of the chaser

The twin blade chaser is essentially a purpose built,twin blade angle grinder. Application and cutting is asfor the angle grinder. The typical rating is 1700 watts(16 amps; 110V). Idle speed is around 7500rpm;weight around 5.6kg. The chaser includes an overloadcurrent limiter, built-in starting current limiter, andprotective thermal motor cut-out. The base plate of thechaser is quick release to allow easy access for bladefitting and cleaning.

The drawings below show the main features.

Twin blade chasing 4.5


Typical 110V twin blade chaser

Key

1 on/off switch

2 slitting controlswitch

3 spindle lockbutton

4 side guard

5 clamping nut

6 spacer

7 clamping flange

8 spindle

9 guide carriage

10 guide point

11 position of innerdisc

12 depth adjustmentpush buttons

13 depth scale

14 slitting directionarrow

15 direction ofrotationarrow (disc)

16 dust removalconnection

17 pin wrench

18 carriage lockbutton

19 diamond discs

1 16 3 2

9

13

11

14

19

18

19

6

1210

4 15

7

5

6

19

6

19

7

8

3mm

6mm

13mm

21mm


Components/acessories

The following items are the basic components of the twin blade chaser:

• diamond blades – typically 2 x 125mm

Chaser with twin blades in view 125mm blade fitment

• blade shaft (spindle) – onto which the blade is mounted

• spacers – fitted onto the shaft (spindle) to accommodate different blade widths

Spacer fitted

• pin spanner – to mount the blades

• depth gauge adjuster – enables the depth to be set to suit the application.The adjuster unclips for ease of access

Depth adjuster




• on/off switch – turns the power on or off

• handles – typically twin handles onto which are fitted the control switches.The soft grip helps to reduce the risk of vibration white finger and gives the user abetter hold

Handle with built-in switch

• dust extraction – an attachment is provided to enable connection to dustextraction equipment

Dust extraction attachment

• carrying case.




The first rule!

Never work with a power saw/cutter that is damaged or incorrectly adjusted, and alwayscheck that the blade stops rotating when the throttle is released.

Maintenance

Always follow the manufacturer’s recommendations. General guidance is given inSection 2.7 Maintenance of tools and equipment, pages 39 and 40.

Basic do's for safe operation

• Look around you to ensure that there are no distractions which could affect yourconcentration, and thus your control of the machine. (Look out, in particular, foranything which could give rise to unexpected movement, e.g. a dumper truck,which could cause you to become temporarily distracted.)

• Make sure that other operatives are a safe distance away before you start themachine (the safety distance is 15 metres).

• Ensure that no material can become loose and fall, causing operating injury.

• Take great care when working on sloping ground.

• Always lower the guard when the machine is running.

• Ensure that the working area is clean, tidy and sufficiently lit.

• Ensure that you have a safe, stable working position, without having to over-reach.

• Always hold the machine in a firm grip with both hands. Hold it so that the thumbsand fingers grip round the handles.

• Secure workpieces using a clamp, vice or other suitable device.

• Make sure that no pipes or electrical cables are routed in the area where youare cutting.

• Start cutting with the machine running at maximum speed.

• Ensure discs, blades, etc. are properly attached (sufficiently tight but notover-tightened).

• Always wear appropriate PPE. In addition to the usual safety helmet, safety bootsand high-visibility clothing, the following items will be required – impact resistantgoggles, hearing protection and suitable gloves.

• Switch off when not in use, remove the plug from thepower supply and store the tool in a safe place.

Basic don'ts for safe operation

• Do not use machinery if any parts are missing or damaged.

• Do not use power tools in the location of flammable liquidsor vapours.

Do’s and don’ts for the safe use of hand held power saws 4.6


Adequate riskassessment,training

and supervision


• Do not use the machine in bad weather, e.g. fog, rain, strong winds or intensecold (working in bad weather is tiring and can lead to a loss of concentrationand/or give rise to dangerous conditions, e.g. a slippery surface).

• Never start to work with the power cutter before the working area is clear of anyobstructions, and ensure that you have a firm foothold.

• Make sure that no clothing, or parts of the body, come in contact with the cuttingequipment when the blade is rotating (any ill-fitting clothing should be removedtogether with tie, watch and other loose jewelry; long hair should be suitablycontained).

• Do not move the machine when the blade is rotating.

• Never use the side or upper surface of the disc for cutting.

• Do not use a power cutter in a situation where you cannot call for help in caseof emergency.

• Do not touch the workpiece immediately after cutting or grinding as it will bevery hot.

• Do not use the cutter or grinder as a fixed tool.

• Do not try to cool the grinding discs with water or other lubricants.

• Do not hold unsecured work in your hand.

• Never leave the cutter or grinder running whilst unattended and never put the tooldown whilst running.

• Do not operate tools when you are tired, or under the influence of alcohol, drugsor intoxicating medication.

Note: Overexposure to vibration can lead to circulatory damage or nerve damage. In thefirst instance, report to your supervisor immediately if you experience symptomsresulting from overexposure to vibration. Such symptoms include numbness/lossof feeling, tingling, pricking, pain, loss of strength, changes in skin colour orcondition. These symptoms normally appear in the fingers, hands or wrists.The risk increases at low temperatures. If the symptoms persist, you may need tovisit your doctor. Where possible, and it is accepted that it may not be very often,hand held tools should not be used if it is practical to use a ‘mechanicallymounted’ machine.

A ‘points’ system has been developed by the HSE which allows for quick estimatesof the hand/arm vibration exposure for a worker. Each process is assigned anumber of points per hour. Adding the points from each process carried out(calculated by multiplying the points per hour by the number of hours use)provides an estimate of the total exposure.Visit www.hse.gov.uk/vibration/hav/readyreckoner to find out more.

Do’s and don’ts for the safe use of hand held power saws 4.6




Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




5.1 General 85

5.2 Selecting the right equipment 86

5.3 Attaching the motor to the stand 88

5.4 Attaching the rig stand to the structure 89

5.5 Drilling operations 91

Section 5 Diamond drilling 5.0

83Section 5 Diamond drilling© Construction Industry Training Board 2007Decorative Concreting CTP 143/C


5.1 List the typical applications for which diamond core drills are used.

List the basic components of a drill rig.

5.2 List some of the factors which influence selection of the appropriate drill rig.

5.3 Briefly describe the three different types of attachment used for connecting a motorto a drill stand carriage.

5.4 List the alternative methods of attaching a rig stand to the structure or other support.

Explain why it is important to use a strut, chain or rope in combination with avacuum attachment.

5.5 State the preparatory checks which should be made prior to starting drillingoperations.

List the key stages (steps) in setting up the drilling rig.


84Section 5 Diamond drilling© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


Introduction

Diamond core drills are used to bore holes into structuralmaterials. The drill bit consists of a steel tube with diamondsegments brazed or laser-welded onto the drilling end.The bit is mounted on a shaft. Core drill machines can beoperated in either a vertical or horizontal direction and can beelectric, hydraulic or air-powered.

The purpose of drilling is to form precise circular cuts to createopenings for building elements, e.g. doorways, windows andlift shafts; and for service penetrations, e.g. ductwork, pipesand cable trays. Diamond core drilling is also commonly usedto create holes for placing anchor bolts, installing load carryingdevices or for taking concrete samples (for analysis).

Drilling rigs

Rigs vary in design but the basic principal is the same. The base plate of the drill standis generally secured to the structure to be drilled using suitable means, e.g. metalanchors, 'acrow' props or vacuum pads.

The power unit (drill motor) is electric, hydraulic (operated by the pressure of fluids) orpneumatic (operated by air pressure). Drilling bits range in diameter from 6mm throughto l500mm or even larger. The smaller the drill diameter, the greater the speed ofrotation. Drilling depths are virtually unlimited if barrel or rod extensions are used.

Diamond drills generally have a water feed through the drive shaft to cool the diamonds,keep the cutting face free of grit, and to maintain an effective cutting operation.The water flow eliminates dust but causes residual slurry to form. This can be removedusing an industrial vacuum cleaner.

Before commencing drilling operations, the contractor must select a drilling machine thathas sufficient capacity to drill the hole sizes required. The power unit selected mustmatch with the available power supply on site, i.e. air, electric or hydraulic. The drill maybe hand held, which is suitable for smaller diameter holes, although general drilling workwill normally be carried out using a purpose built drilling rig fitted with a motor. Most drillsare suitable for drilling into floors and walls but certain models may not be designed fordrilling into ceilings or at an angle and upwards into walls, particularly if the motor is notprotected from water spray. In this situation a hydraulic motor may be more suitable.Also, the manufacturers of drilling equipment may have ancillary tools that can be usedfor drilling to suit specific situations.

General 5.1


Competence



and skin


The drill rig

Rig selection will depend on a number of factors. The following tables will assist in theselection process.

Note: A flow meter is required for checking the flow rate. However, as a guide, if coolantcan be seen escaping from the side of the core barrel then the flow rate isprobably acceptable.

Selecting the right equipment 5.2


Bitdiameter(mm)

20

41

52

82

102

127

152

162

178

210

225

250

250

350

400-650

Maxspeed(rpm)

3000

1700

1100

750

650

550

475

400

325

300

275

260

200

185

Minspeed(rpm)

2000

1100

600

500

450

375

300

275

250

225

200

190

150

125

Optimumspeed(rpm)

2500

1400

900

650

500

475

375

375

285

250

225

215

175

150

Waterflow

(litres/min)

3

3

3

4-5

5-6

6

7

7-8

8

9

9

10

11

12

12>

Equipmentcode

A/B

A/B

A/B

A/B

B/C

C/D

D/F

D/F

D/F

D/F

D/E/F

D/E/F

D/E/F

E/F

E/F

Equipment selector table

Electric or high speed hydraulic handheld motor.

Hand held with lightweight drill stand.

1.8KW 110V motor mounted tomedium weight drill stand.

2.2KW 110V motor with heavy dutydrill stand.

3.0KW 3-phase motor with heavyduty drill stand.

Variable speed hydraulic motor withheavy duty drill stand.

n/a

Vacuum/anchor

Vacuum/anchor

Anchor/'Acrow'(telescopic stand)



A

B

C

D

E

F

Code Equipment Attachment

Key


Drills and stands

The following hand held drills and stands are typical examples of the types ofequipment used.

Electric drill Hydraulic powered drill

Electric drill mounted on a Hydraulic powered drill mountedlightweight stand on a heavyweight stand




General

A suitable attachment is required in order to fit a motor to thedrill stand carriage. The exception is rig models whichincorporate the mounting into the carriage. Attachments areconnected in one of three ways depending on the type used.

Note: Other purpose designed motor attachments are available. One example is theclapper mounting attachment which consists of two hinged plates. These allowthe motor to swing to the side for access and thus assist in removal of the core.This type of attachment is often used for deep hole drilling.

Attaching the motor to the stand 5.3


Motor clamped to a mountingbracket which is bolted to the stand

Motor bolted to the mounting platewhich is secured to the stand. A

keyway assists location and alignment,and also provides extra security

The mounting is in two sections: the carriage block,which is secured to the carriage; and the motor block,which is secured to the drill motor. The two blocksdovetail together and are locked into place by meansof a side bolt. This type of mounting is normally usedfor large capacity motors as it allows the motor to beseparated from the carriage for ease of handling.

Manualhandling


Types of attachment

The drill rig can be attached to the structure in one of four ways:

• anchor (dowel)

• vacuum

• brace (‘Acrow’ system)

• ratchet strap.

Anchor (dowel) attachment

A rotary percussive hammer drill and bit is used for drilling the holes in order to acceptthe fixing anchor specified. Before considering anchor attachment, ascertain whether thebuilding structure is suitable. M12 anchors should be used for cores up to 250mm; M16anchors for cores of 250mm diameter or greater. The anchors should never be placedcloser than 20cm to the edge of the structure.

The distance between the centre of the core and the drill stand base anchoring slot willvary according to the model being used and the application. Check the manufacturer’sinstructions.

Vacuum attachment

The drill rig is attached to the structure by generating a vacuum between the two. This isachieved by a vacuum pump and base connected to a suitable power source.

When drilling into walls, a strut, chain or rope must be used to anchor the rig fromabove. This will take the weight of the rig in the event of a loss of vacuum, resulting fromequipment or power failure. The following points provide general guidance on setting upand use.

1. Do not start drilling until a vacuum of 0.7 bar has been reached.

2. To secure the rig, hold the drill stand tight with both hands, adjust the alignment asrequired, and then release the vacuum valve. Operations can commence once thespecified vacuum has been reached.

3. Only use vacuum attachment when drilling holes of 127mm maximum diameter.

4. Ensure that the wall covering is adequately and solidly attached to the wall(plaster has been known to come away with the vacuum suction).

5. Ensure that the surface quality is adequate for rubber sealing (minimum vacuum0.7 bar).

Attaching the rig stand to the structure 5.4



Attaching the rig stand to the structure 5.4


Some rigs have purpose built base plates.

Vacuum pump and separate base plate

The setup procedure is as follows.

1. Connect vacuum pump to power supply.

2. Connect the hoses.

3. Position the vacuum base firmly against the surface.

4. Turn on the pump.

5. Wait for the pressure to build to 0.7 bar.

6. Fit the rig base to the vacuum base.

Brace attachment (‘Acrow’ system)

Some drill stands use a telescopic system thatallows the length to be extended.The stand can then be extended to bracebetween structural supports, e.g. from floor toceiling. Height adjustment is achieved byraising the column and locking into position byinserting a steel pin. The threaded shaftenables final height adjustment to be made sothat the stand firmly braces between supports.

Ratchet strap attachment

This is typically used to secure the drill stand toa suitable support, e.g. a concrete pipe.The canvas strap is wrapped around the pipediameter and rig base, and secured byconnecting the two hooks. The strap istightened using the ratchet by pulling forwardsand back. This action reduces the strap lengthuntil the strap is taught.


Preparatory checks

Before starting drilling operations it is important to carry out a number of site checks.These will assist in the right choice of equipment and its safe use.

1. Ascertain the nature of the material to be drilled and determine the best methodof attachment.

2. Determine the position of services (water, gas and electricity supplies near to thework area should be turned off prior commencing drilling operations).

3. Determine the position of reinforcement (never cut through steel reinforcement orstructural steelwork without the client's permission).

4. Check the reverse side of any wall areas to be drilled, noting the position of anyelectrical or other installations.

5. Check underneath any floor areas to be drilled (cores can drop from the bit whendrilling, therefore warning signs need to be in place and physical protection providedwhere appropriate).

Setting up the rig

The setting up procedure involves five stages. Before starting, check the manufacturer’sspecified measurement from the anchor to the centre of the hole/aperture to be drilled.

Stage 1 – Anchoring the rig

1. Using a rotary percussive drill with a 16mm drill bit, drill into the structure to a depthof 65mm.

2. Clean out the hole using a bellow tool.

3. Insert the anchor into the hole to its full depth.

4. Insert the setting tool into the anchor and hammer the nugget to expand theanchor diameter.

Note: If the seating punch does not turn, the anchor is set.

5. Insert and tighten the clamping bolt.

Stage 2 – Fixing and leveling the rig

1. Place the rig base over the clamping bolt and tighten the spindle clamp until the rigis secure.

2. Check the levels, using the spirit level on the rig column, and adjust by turning theadjustment bolts on the base.

Stage 3 – Mounting the motor and bit

1. Mount the motor to the carriage using the purpose designed mounting plates.

Drilling operations 5.5



2. Fit the core drill bit to the motor spindle and tighten using the appropriate spanner(varying thread connections and adaptors are in common use).

3. Make any final adjustments in position relative to the centre of the intended hole.

Note: Ensure that the final set up is accurate (within the specified tolerance) to thecentre of the hole. Horizontal and vertical levels should be checked using aspirit level.

Stage 4 – Drilling

1. Connect the water supply to the drill motor.

2. Select the appropriate motor gear (refer to manufacturer's literature for drill speed).

3. Connect the 110V electricity supply, ensuring drill motor is in the OFF position.

4. Lower the drill bit to within a few millimetres of the surface, turn on the motor andslowly connect the core barrel to the surface, remembering to maintain a firm hold onthe handle throughout the drilling process.

5. Start drilling, forming a shallow groove, then turn on the water supply (ensuring acontinuous clean supply).

6. Apply steady pressure using the carriage handle, allowing thecore to turn at optimum speed, remembering to observe therig base (if too much pressure is applied the base will movefrom its position). Too much pressure can also damage thedrill motor armature and the diamond core bit.

7. Drill to the required depth. If the required depth is greaterthan the length of the core bit, extract the drilled material, refitthe core bit with an extension bar attached, and continue drilling.

Stage 5 – Removal

1. Extract the core bit from the hole by reversing the carriage. Approximately 25mmbefore extraction, turn off the motor and the water supply.

Note: Leaving the core barrel approximately 25mm inside the hole will steady theseparation process.

2. Unscrew the core from the motor using the appropriate spanner(s), remembering toallow for the extra weight of the drill core.

Note: The core can become jammed. In this instance, light tapping with the flat sideof a spanner can assist in un-jamming. Other purpose-made tools can alsoassist, such as a chisel to break the core or a brazing rod bent at a 900 angle,5mm up, to act as a ‘catcher’. Take care not to damage the core barrel as thiswill prevent the core being extracted.

Maintenance


Drilling operations 5.5


Hearingprotection



Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




6.1 General 95


6.3 Understanding the machine controls 97

6.4 Sawing operations 99

Section 6 Floor sawing 6.0

93Section 6 Floor sawing© Construction Industry Training Board 2007Decorative Concreting CTP 143/C


6.1 List the typical applications for which floor saws are used.

List the basic components of a floor saw.

6.2 List some of the factors which will influence selection of the appropriate saw.

6.3 List the main floor saw controls and briefly describe their main purpose.

6.4 Explain the procedure for moving a floor saw up or down a ramp (or incline).

Describe the procedure for fitting a new blade.

State why a floor saw requires a water supply.

Describe the procedure which should be followed in order to make a saw cut.


94Section 6 Floor sawing© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


Introduction

Floor saws are specially designed for cutting concrete, asphalt and various stonematerials. They use diamond tipped blades which are supplied in a variety of sizes.The saw can be manually handled but is more generally used as a self propelled unit.The machine has a movable frame, onto which the various components are mounted.Floor saws are fitted with a petrol engine, diesel engine or electric motor. Adjustmentsare included for depth and speed. Different models will vary in their design and thelocation of controls but the basic function remains the same.

Floor saws are used extensively on roads and motorways to cut asphalt and concrete.They produce a clean, quick saw cut which enables efficient repairs and alterations to becarried out. Floor saws offer a number of advantages over alternative cutting techniques:

• minimal setting up

• built in power unit

• very rapid cutting.

General 6.1




and skin


Selector chart

The maximum cutting depth, operating speed and maximum safe speed will depend onthe drill diameter, as the following table demonstrates.

Saw selection/peripheral speed chart

Notes: * Based on 9,500 SFPM (surface feet/minute) which equates to 48 metres/second.The general optimum performance range for cutting concrete and masonryproducts is ± 10%. For hard, dense materials such as stone and tile, the optimumperformance speed is 10-25% less than the speed shown in the table. Bladeshaft speeds (rpm at no load) for most tools will be higher than the recommendedoperating speeds shown. Under normal sawing conditions, the actual blade shaftspeed of the tool will slow down under load, and should fall within the optimumspeed range.

** The speed (rpm) represents the maximum safe speed at which each blade canbe used. Before using any blade, make sure the blade shaft (arbor) speed of thetool is within the maximum safe limit of that blade. The abbreviation HS refers toa High Speed diamond blade.



Operating speeds Max cutting depth

Diameter Operating speed* Max safe speed**inches mm rpm rpm mm

14 356 2,592 4,400 127

16 406 2,268 3,800 143

18 457 2,016 3,400 168

20 508 1,814 3,000 203

22 558 1,649 2,800 216

24 610 1,512 2,500 241

26 660 1,396 2,300 270

28 711 1,296 2,300 279

30 762 1,210 2,000 292

32 813 1,134 1,900 321

36 914 1,008 1,800 368

42 1067 864 1,500 450

48 1219 756 1,200 527

Competence


The following dials and controls will need to be understood in order for operatives to usethe saw safely. The parts illustrated are typical examples. In practice, the layout anddesign of individual switches will vary according to the machine model/manufacturer.Always consult the manufacturer's operating manual for the specific saw being used.

Main control panel

Understanding the machine controls 6.3


Key

1 Oil pressure gauge

2 Voltmeter

3 Water pump switch

4 Switch for lights

5 Ignition switch

6 Tachometer

7 Depth indicator

8 Throttle cable

9 Choke cable

1

2

5 6 7 8 9

3 4

On/off(diesel engine switch

illustrated)

Voltmeter

Tachometer dial whichindicates the engine revsand also houses the engine

running hours

Fuel tank cap with built infuel level indicator

Oil pressure guage

Water safety, blade raise orlower on/off, and drive shaftswitches. The water safetyswitch cuts the engine if thewater supply is interrupted ornot present. The blade raise orlower on/off switch activatesthe raise/lower control.

The drive switch activates theblade rotation

Note: Petrol engines include a choke switch which increases the flow of fuel to thepistons when starting the engine from cold.


Understanding the machine controls 6.3


Blade raise/lower lever and speed control lever.The blade raise/lower lever raises or lowers the blade.The speed control lever controls forward and reverse

directions, stop and speed of the saw. It allows transmissionto be shifted through low/neutral/ high

Position depth stop andindicator which allows thecutting depth to be adjusted.The maximum cutting depth islimited by a stop on the spindle

Governor lever which limits the engine speed.The lever is set to suit the maximum recommended speed for

the diameter of blade being used (petrol engines only)

Pointer. The metal section,which is connected to the sawframe, with a guider at the

end. It assists the operative infollowing line markings

Air filter which collects particles from the incoming air,i.e. airborne dust, thus preventing damage to internal engine

parts. The filter is located on the air manifoldOn/off tap to control water

feed to the blade


Preparatory

Floor saws are bulky and heavy and care needs to be exercised when unloading andhandling. Remember to remove the blade when moving the saw up or down a ramp.To go down a ramp, reverse the machine slowly using engine power, or a winch with thetransmission in neutral. To go up a ramp, drive the machine slowly, lifting the frontsection up so as not to hit the top surface of the ramp. Alternatively, use the winch topull the saw up. Once in place, lower the saw to the ground (floor) and strap it usingratchet straps (or similar).

Note: If using the machine's own drive for manoeuvring, ALWAYS remove the blade firstto avoid injury.

Setting up the saw

Stage 1 – Fitting the blade

1. Set the engine start switch to theOFF position.

2. Loosen the bolt on the blade guard latch (if fitted).

3. Unscrew the bolt on the blade shaft and remove the outer flange.

4. Raise the machine to the required height using the depth/raise lever.

5. Raise the front half of the blade guard.

6. Fit the diamond blade to the inner flange plate, ensuring that the direction arrows arepointing in the direction of cutting. There is a corresponding cutting direction arrowon the blade guard and it is important that these arrows point in the same direction.Make sure that the surfaces on the blade and the inner and outer flange plate areclean and in contact with each other.

7. Install the outer flange anchor into the blade shaft, making sure that the locking pinpasses through the diamond blade and into the inner flange.

8. Install and tighten the blade shaft bolt using the shaft wrench. When tightening, keepa firm hold on the diamond blade.

9. Rotate the outer flange and diamond blade, in the opposite direction to bladerotation, in order to remove the backlash (kickback).

10. Lower the front half of the blade guard and tighten the bolt on the blade guard latch(if fitted).

Stage 2 – Checking and adjusting the water supply

Water is required as a coolant and also for flushing out debris from the cut. Too muchwater may cause the blade to polish the segments; too little may cause overheating ofthe segments, leading to segment loss and undercutting of the steel blank. Somemachines have in-built pumps to assist the flow of water to the blade. The followingchecks and operations should be carried out.

Sawing operations 6.4


Manualhandling

Certification forfitting blades


1. Ascertain the type of water supply. This can vary from mains pressure taps throughto 'bowsers' and purpose built water tanks.

2. Check the water pressure. It should be sufficient to supply a minimum of 9–14 litres(2–3 gallons) per minute to the blade.

3. Check and align the pointers (some machines have a depth gauge indicator and stop).

4. Connect the water supply to the saw.

5. Pull out the handle bars to the desired length and tightenthe securing knobs.

Stage 3 – Sawing to the required depth (step method)

1. Lift the blade from the surface using the depth/height lever.

2. Start the floor saw by turning the engine start switch to RUN.

3. With the clutch in neutral, let the engine warm up for several minutes with the enginespeed switch set to idle.

4. Engage the clutch.

5. Manoeuvre the saw to the pre-marked cut line.

6. Align the blade and pointer to the cut.

7. Bring the power to full revs by pulling the motor speed lever outwards.

8. Turn on the water supply and set the speed control lever to its central position.

9. Slowly lower the blade approx 30mm into the cut by pushing forward the bladeraise/lower hydraulic control lever.

10. Slowly move forward, turning the forward control lever to a speed setting that allowsthe blade to cut within its operating speed.

11. Saw to the end of the cut line.

12. To achieve further depth, lift the blade out of the cut, take the saw back to theprevious starting position and align the blade and machine to the cut line.

13. Lower the blade into the cut to the depth required (or to the blade's maximumdepth capability). This process may take several passes to achieve the depthrequired depending on the material being cut.

14. Repeat the process until the required depth is achieved.

Note: Do not force the machinery as the blade will lift out of the cut.

Maintenance


In addition:

• Grease points after 8 hours of use

• Check the tension of shaft belts daily and adjust if necessary.



PPE for dustand noise


Section 7 Track/wall sawing 7.0

101Section 7 Track/wall sawing© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




7.1 General 103


7.3 Understanding the machine's components and controls

105


7.1 List the typical applications for a track/wall saw.

Explain what is meant by the pass method of cutting.

State the typical range of saw blade diameters in common usage.

7.2 List some of the factors which will influence selection of the appropriate saw blade.

Explain why pre-cutting is recommended when using larger diameter blades.

Explain why pre-cutting is essential when using blades of 1m diameter or greater.

7.3 List the main machine components and explain their function.

Explain the purpose of the remote control unit and list the main control functions.

7.4 Explain the sequence of preparatory steps that are required prior to commencingcutting operations.

Describe the procedure for fixing the rail onto the concrete/masonry.

Describe the procedure for mounting the saw head onto the rail.

Explain the supply connections which need to be made.

Describe the procedure for mounting the saw blade and guard.

Describe the procedure for making cuts.




Introduction

Track/wall saws are used to cut door and window openings in reinforced concrete andmasonry. They are also used to cut into floors to form lift and stairwell openings,particularly in situations where the use of a floor saw would be neither practical nor safe.

The saw consists of an aluminum rail which has a set of supporting feet/mountingbrackets. These are secured to the material to be cut by means of fixing anchors.The rail has a toothed rack that engages the rack and pinion gear onto the saw head toenable it to travel on the rail. The head also houses the motor which is poweredhydraulically, pneumatically or via an electrical supply.

Blade sizes typically range in diameter from 450mm to 2000mm. The blade can beoperated by remote control, away from the surface of the cut, or manually via a socketconnected to the gearing worm. Cutting is carried out by making a series of passesalong the length of the cut (known as the 'pass method' of cutting). The depth of eachpass depends on the nature of the material being cut, the blade used and theskill/preference of the operator. Generally, a starter blade of 450–600mm diameter isused with a width greater than the subsequent blade to be used. This will facilitate bladeinsertion into the cut.

Typical trackwall saws

General 7.1




and skin

Refer tooperators manual

for the saw


Choosing the saw blade

Most saw blades have a 60mm arbor mounting hole althoughthis can vary depending on the manufacturer. For flush cutting,the saw blade is mounted on a specially designed flange plateand fitted with six Allen-head counter sunk screws. Saw bladesmust be rotated at the correct speed and in the right direction.Refer to the manufacturer's instructions.

The following table gives the maximum cutting (and pre-cutting) depths for differentblade diameters.

Note: Small diameter saw blades generally give a longer life. Pre-cutting, using a smalldiameter saw blade, is recommended for saw blades larger than 700mm. The useof pre-cut blades is essential prior to cutting with a 1000mm (or greater) diameterblade, as these larger blades will not fit on the machine due to the limitations ofworking height.



Blade diameter Maximum cutting depth Recommended pre-cutting depth(mm) (mm) (mm)

450 150 –

500 175 –

520 185 –

600 220 –

650 245 –

700 270 500/600

750 295 500/600

800 320 500/600

900 370 500/600

1000 420 500/600

1200 520 500/600

1500 670 500/600

Competence


Machine components

Saw head

The saw head is the most important part of the machine. The saw motor, diamond sawblade and blade guards are all mounted on the saw head. Also, the mechanical andelectrical components for saw blade traction, drive and penetration are integrated into it.The saw head is fixed to the rail by slide blocks that provide stability and clearanceabove the rail.

Saw head

Blade guard

The guard provides protection and also reduces the amount of cooling water over-spray.There is a choice of a standard or flush cutting guard. The front and rear of the standardblade guard can be disconnected very easily to facilitate sawing in corner positions.Blade guards are supplied in sizes from 600mm up to 1500mm. Flush cut guards mustalways be used when flush cutting.

Blade guards

Understanding the machine’s components and controls 7.3



Power unit

Power packs are generally either hydraulic or operate using high frequency electricalcurrent.

The hydraulic pump draws hydraulic oil from the oil tank. It then pumps the oil into thepressure hose and through the remote control unit. Here it is divided into two flows, onefor the blade drive motor and the other for the feed system. These flows can beseparately adjusted using volume control valves. The two way control valve allows theoperator to change the direction of the feed. The oil flows from the remote control unitthrough the hoses to the blade drive motor and feed motor, and then back via the oilcooler and return filter to the oil tank. The feed motor is powered via a three-phaseelectricity supply or is engine driven.

The high frequency electric motor is powered by a 'powerbox'.Cables have to be connected between the motors and thepowerbox and the remote control unit must be attached.Poweris provided from a three-phase electricity supply.

Typical hydraulic power unit

Rail

The rail guides the saw head and determines the position of the cut. The rail is madefrom steel or aluminum box section and includes a tooth-rack system for the motor headto drive along. The rail is wall mounted by means of brackets.

Typical guide rail



Electrical hazard


Mounting brackets

These connect the rail to the material to be cut and are available in various designs andsizes. The saw can only be used safely and efficiently when the mounting brackets arefirmly anchored to the base material. Always ensure that the brackets are tightened tothe recommended torque to avoid the risk of loosening and subsequent pull-out.

Typical mounting bracket

Stop ends

These are attached at either end of the rail to prevent the motor from running off therail ends.

Typical stop end






!

Machine controls

Remote control unit

There are two types of remote control unit, one that is integrated into the power unit andone that is portable. Both have the general function of operating the wall saw and housethe drive and depth speed controls, including forward and reverse. Some units havepressure gauges to assist the operator in the cutting process. Electrically operatedremote control units incorporate an emergency stop button, phase indicators, bladerotation guide and variable speed controls.

Key

1 Saw blade drive motor ON/OFF Turn to start (switch returns to position II when released)Position II = saw blade drive ON (running)Position I = saw blade drive OFF

2 Saw blade speed Infinite (without steps) speed regulation

3 Direction of advance switch Selects the direction of advance of the saw on the rail

4 Direction of plunge movement switch Selects the direction of saw blade plunge movement

5 Speed regulation for controls Manual and/or automatic advance or plunge movement(3) and (4)

6 Rapid movement for control (5) For rapid advance and plunge movement when the saw bladedrive is switched OFF

7 Cooling water ON/OFF switch Controls the cooling water supply to the saw blade.Water flows when the saw is not under power

8 Emergency OFF switch Press in an emergency! Leave pressed in when setting up orchanging blades.Turn knob in direction of arrow to release

4 3 18 20 8 17 2

19 7 9 10 11 12 13 14 15 16 1 5 6

Key continued overleaf


Note: Some models have a cutting depth indicator located on the saw head or theblade guard.



9 Overheating cut-out Lights when the machine has switched itself OFF due tooverheating

10 Temperature warning Lights when the cooling is inadequate

11 Zero position error Lights when one or more knobs are not in the zero or neutralposition when switching ON

12 Emergency off indicator Lights when the emergency OFF button is pressed or whennot reset

13 Fault in electric supply Lights when a phase is missing, voltage is too low or toohigh or out of synchronisation

14 Service indicator Lights when a service is due (servicing should be carried outby the manufacturer or approved agent)

15 Theft protection Not active

16 Emergency off indicator Lights when the emergency OFF has not been reset

17 Operating hours counter After switching on, the total number of hours that the sawhead has been in operation is displayed

Power indicator The actual power input is displayed during operation ofthe saw (in %)

Supply voltage During operation, turn starting switch (1) to the 'start'position (voltage is displayed)

Fault indicator The code displayed can help to localise a possible fault,e.g. Er01

18 Speed indicator Can be adjusted by knob (2)

19 Warning Operation of the saw without blade guard and endstops fitted is not permissible!

20 Recommended speed range Shows the permitted speed range


Preparation

1. Establish if over cutting is allowed.

2. Determine the sequence of cuts to be made. For a door opening, first make thebottom cut; the other cuts can be made in any order as long as the track is notanchored onto the section being removed.

Note: The amount of anchor points that are required can be kept to a minimum bypositioning the holes to suit the position of cutting lines.An example of a cutting sequence is shown below.

Example of a sequence for making the cut lines

3. Ensure that the section to be cut is clearly marked, e.g. by the client.

4. Make dividing cuts in order to adjust the size and weight of concrete blocks so as tosuit the site conditions, e.g. work order, means of handling the blocks, availability oflifting equipment, the maximum floor loading capacity and ease of egress.

5. Use steel wedges and supports (as necessary) to secure the section of concretewhile sawing.

Note: When the opening is being cut, wide shallow wedges must be installed at bothsides of the wall to restrain the slab. If this is not possible, e.g. when multiplesections are to be cut, each slab must be tied into the supporting wall by crossbars or anchors. The saw should be mounted onto the surrounding wall when thefinal cut is being made. If one or all of the track brackets are mounted on thesection to be removed, then the section must be restrained using cross bars andanchors. When removing the restraining bars or wedges, a 150mm thick slab willtilt out of the opening without interfering with the surrounding wall; a 225mm thickslab will cause a slight interference and may lodge in the opening or tilt right out;a 300mm thick slab must be moved horizontally before it is tilted out, in order toclear the opening.

6. Determine the length of rails which are required.

7. Check, if possible, the concrete quality together with theamount and position of steel reinforcement.

8. Check which anchor system is required for mounting the brackets onto the concrete.

Note: Ensure that all health and safety measures are in place and being followed. It isparticularly important to provide support, as detailed in the Method Statement, forthe piece of concrete being cut out, especially when cutting into roofs or ceilings(a 1m2 section of concrete weighs about 2600kg!).



Risk assessment

Mechanicallifting aids e.g.overhead crane,

hoist andpulley systems


Fixing the rail onto the concrete

1. Mark the anchor positions. The distance from the anchor position to the line cut mayvary depending on the type/model of track used. Generally, the distance will rangefrom 140mm to 285mm. Always check the manufacturer's instructions.

2. Drill holes for the anchors. A minimum M12 anchor is required for a hole diameterof 15mm.

Note: On masonry, resin anchors or through rods may be used. Observe the installationinstructions given by the anchor manufacturer for setting the anchors.

3. Position the rails brackets. When using one rail, fix brackets at both ends.When using more than one section of rail, fix brackets at 1m maximum centres.

4. Mount the fixing anchors in the concrete (only use approved/certified anchors).

5. Secure the brackets to the concrete.

6. Mount the rail onto the brackets.

7. Align the rail, making sure that all the levelling bolts are in contact with the concreteand that the rail is not under torque.

Note: On extremely uneven surfaces, suitable shims or packing pieces must bepositioned (as required) beneath the rail supports. Alternatively, if rail supportadjustment screws are provided they can be adjusted accordingly. Use a rubbermallet when hammering directly on to the mounting bracket or rail.

8. Mount end stops on the rail to prevent the saw head from coming off the rail.

Mounting the saw head on the rail

The saw head is mounted by the action of cam-rollers being opened and closed or bymeans of a lever system that clamps the head rollers onto the rail.

A variety of saw heads is in common usage. They employ different systems for securingthe head to the rail. Always refer to manufacturer's use instructions. The followingprocedure is offered for guidance and should be read in conjunction with the illustrationand key which follow.




1. Move handle 1 into the lowerposition and handle 2 into theupper position.

2. Lift the saw head using grip 3and handle 2.

3. Mount the saw head on the rail.For flush fitting allow +2cmbetween blade and wall fortilting the saw head.

4. Press the trigger grip, which isintegrated into handle 2, andpush the handle downwards tolocate the saw head on the rail.

5. Move handle 1 into the upperposition to fix the saw head inposition.

6. Check that there is adequateclearance between the slideblocks and the guiding bars(located in the side of the rail).

Making the connections

1. Connect the power cables from the power box to the saw head.

2. Connect all hydraulic pipes (if applicable) from the power unit to the saw head.

3. Connect the remote to the power box.

4. Connect the three-phase supply to the power box.

5. Connect the water supply to the power unit and then to the saw. The connection pointmay be direct onto the saw head or blade guard.

Note: Cool, clean water must be used. A flow rate of 4 to 7 litres per minute is required.Some machines have a sensor that will cut off the power if the water pressurefalls below a predetermined level.

6. Connect the outlet on the power unit directly to the motor.

Note: On certain models there may be a T-junction on the motor outlet, which divertsand controls the water flow to the blade.



1 2

3

Saw head mounted on its rail

Key 1 Handle2 Handle3 Grip


Mounting the saw blade

1. Mount the saw blade with the flange and bolt engaged intothe rotating saw arm. For flush cutting, mount the saw bladeusing six Allen screws which locate into the special holepattern provided.

Note: A variety of systems are used to connect the blade to thesaw head. Always follow the manufacturer's use instructions.

Mounting the saw blade

2. Check the angle between the saw blade and the concrete. The angle must be 90˚,otherwise serious injury could result. If the angle is not 90˚, adjust the rail using thelevelling screws on the mounting bracket.

Mounting the blade guard

Blade guards are used to divert the used water flow in a controlled manner and also tosafeguard the operator from injury. The blade guard securing system will vary accordingto the make/model of machine. Always follow the manufacturer's use instructions.

1. Connect the guard centre section to the motor head swing arm mounting post.

2. Connect the end section(s).

Note: When cutting in corner positions, the end section of the guard can be removed toenable the cut to be completed.

Before cutting, check the following:

1. Segments of the saw blade are open.

2. The saw blade is mounted in accordance with the turning direction of the saw shaft.

3. Cables are clear of the area of sawing (to avoid jamming or damage).

4. Brackets and rails are properly fixed.

5. End-stops are secured.



Certification formounting abrasive

wheels


6. Cooling water is clean and the flow is sufficient to cool the saw motor and blade.

7. The RCCD switch in the switchbox is in the ON position.

8. The emergency control switch is disengaged.

9. The power supply is turned on.

10. The water supply is turned on..

Making cuts

The whole cutting process can be controlled using the remote control unit.

1. Use the plunge and advance controls, together with the speed regulation control,to move the saw head along the rail to the starting position.

2. Return all switches to the neutral (or zero) position.

3. For rapid movement, turn the speed regulation control to the right, beyond thepressure point and as far as it will go.

4. Switch on the cooling water.

5. Switch on the saw blade drive.

6. Use the speed control to set the desired speed and pause to allow the blade to'run up' to speed.

7. Select the direction of plunge movement and the advance speed.

8. Bring the blade slowly to the desired cutting depth.

9. Set the plunge movement and speed regulator back to the neutral (or zero) positionwhen the desired depth has been reached.

Note: The first cut should be shallow toapproximately 30mm depth andshould always be made with the sawin a trailing position.

10. Select the direction of longitudinaladvance and the desired speed.

11. Make the initial cut at reduced power(60%).

12. At the end of the cut, turn the speedcontrol to the neutral position andswitch off the longitudinal advance.

13. Repeat steps 7–12 until the desired cutdepth has been achieved. Use differentdiameter blades (1200mm maximumdiameter), as is required in order toreach the required cutting depth. Pass cutting to achieve the required cut depth



25mm

Noise and dust

End view

Front elevation


14. Once the cut has been completed, or the maximum depth reached, use the plungemovement directional control to lift the saw blade out of the cut. Do this while theblade is still rotating, bringing the saw and the saw arm to the 90º position.

15. Turn all switches, i.e. advance direction, advance speed, blade speed, water supplyand starting switch, back to the neutral position and then press the OFF button.

Note: Never disconnect hoses/cables or remove the blade guard when the machine isswitched on and running.

Trouble shooting

Saw cuts out during cutting

Check the load indicator lights for the electric saw motor. The lights have differentcolours and indicate the temperature of the saw motor as follows.

RED = Failure. The machine is stopped, so you need to check for electricalfaults/interruption to the supply. Also check the water supply. The system can be resetafter making the necessary checks and rectifying any faults in the supply.

YELLOW = Attention! The motor is being driven on full capacity and will overheat. In thiscase the RED light will come on and the saw will automatically cut out. For optimal useduring sawing operations, aim to keep the LED flickering between ON and OFF.

GREEN = The power is on, current is flowing and the temperature of the saw motor iswithin its permitted operating range.

Note: If the automatic cut-out operates, and also in situations when the machine isstopped for resetting the rail and brackets, the saw motor must be cooled bycirculating sufficient cooling water through the motor jacket before resetting orrestarting. In extreme cases, this can take up to an hour.

The saw can only be started again when the green load indicator light is on. It isgood practice to check the load indicator light during and after the cuttingprocess in order to minimise down-time. The saw motor should be cooled at theend of cutting operations for a minimum of 10 minutes. Insufficient cooling cancause the motor to overheat even when it is not in operation.

Jamming of the saw blade

When sawing lengthwise into steel reinforcement, makesure that the bar is cut through in one pass. When cutting inmultiple passes, problems can occur due to the sawblade jamming.

Note: Do not use full power when sawing steel reinforcement as this will result in thediamond segments becoming polished.



Competence


Disconnecting and cleaning

1. Remove the blade guard.

2. Remove the saw blade and store the tools in a safe place (or screw them back intotheir retaining holes).

3. Position the saw arm in its lowest position.

4. Disconnect the power supply cable from the switch box.

5. Locate the protective covers onto cables and plugs.

6. Clean the equipment with water. Avoid contact of water with the switch box whichshould be cleaned using a cloth. Do not use a pressure cleaner on electric components.

7. Disconnect the saw motor from the saw head and store the motor, together with cables,remote control and switch box, in a safe place, e.g. in the wooden transport box.

8. Remove the rails and brackets.

Maintenance


In addition:

• Protect guide rails when not in use

• Every 6 months, check the belt tension (saw arm) and adjust if required.




Section 8 Bursting 8.0


Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




8.1 General 119


8.3 Bursting operations 124

117Section 8 Bursting© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


8.1 State the purpose of a concrete burster.

Explain briefly how the burster is able to split concrete.

8.2 List the main factors to consider when selecting the most appropriate burster head(s).

List the main components of the burster head.

State how a wedge is used.

8.3 State the two alternative grid patterns used when drilling holes into the concrete atthe start of bursting operations.

State why it is important to align the burster head correctly when inserting into thepre-drilled holes.

Explain why different sizes of drill hole are required.

Explain why it is important to insert the head centrally into the slab.

Explain why additional wedges are sometimes inserted to further expand thefracture lines.




Introduction

Concrete bursters (sometimes referred to as ‘splitters’), are incommon use in the drilling and sawing industry. They arepreferable to sawing as a means of demolishing concretestructures as they are a more effective at controlling dust,hand/arm vibration and noise.

The burster has a circular metal housing that accommodatesthe pistons. These extend outwards under hydraulic pressure tocrush the material and induce fractures (cracks). The burster isconnected to a hydraulic power unit and can be powered froman electrical supply, diesel or petrol engine. It is operated fromthe remote control unit.

Before using the burster, holes need to be drilled into theconcrete, using a diamond drill bit, for the burster head to fitinto. These holes are drilled in either a straight line or adiamond grid configuration. The distance required betweenholes varies from 450mm to 1m depending upon the type andstrength of the concrete.

Pressure is applied from the hydraulic power pack via thehydraulic hoses. Provided that the burster head is correctlypositioned, the resultant cracking will follow the plane ofweakness to the adjacent hole. This process is repeated untilthe whole area is fractured and ready for removal.

Typical concrete burster heads

General 8.1


Effective controlof risk



and skin


GeneralIt is essential to select the correct type and specification of equipment for a particularcontract. The hydraulic power unit should be sufficiently powerful to run the number ofburster heads being used. Burster heads are available in sizes to suit the job. Whilst thedifferent makes/models of concrete burster will vary in their design, the function remainsthe same.

Hydraulic power unit

Refer to the illustration and key which follows. The power pack is mounted into achassis (15) which consists of a robust tubular steel frame. The chassis houses thepower unit, the oil reservoir (10), the hydraulic control unit, the hydraulic booster (6),and the four hydraulic cocks (8). The pressure gauges (4) and (13), the control valve (18),the manual starter device (14) and the hydraulic connections (8) and (11), are located inthe outer part of the chassis for ease of access.

Selecting of the right equipment 8.2


1 2 3 4 5 6

18

17

161514

13

12

7

8

9

11 10

Key Hydraulic power unit

1 Handle 10 Oil reservoir2 Sound absorber 11 Low pressure connections3 Cover plate 12 Engine4 Pressure gauge (2500 bar) 13 Pressure gauge (250 bar)5 Oil filter neck 14 Starter6 Hydraulic booster 15 Chassis7 Radial piston pump 16 Fuel tank8 High pressure cocks 17 Air filter9 Oil drain plug 18 Control valve

Risk assessment


The drive unit is mounted in a transverse position onto the chassis. It consists of theengine (12) and the radial piston pump (7). The pump is connected to the engine via acoupling. The engine is equipped with a sound absorber (2) and a manual start device.

The oil reservoir contains the pressure control valves and the directional control valve forthe booster circuit and the return filter. The oil filter neck (5) is located on top of thecover plate (3).

The hydraulic booster (6) is a pressure intensifier. It increases the working pressure of thebooster circuit at a rate of 1:25. This enables the pressure in the booster circuit toincrease to 2000 bar within the high pressure circuit. The unit therefore incorporates bothlow and high pressure hoses.

Each hydraulic cock is fitted with a hydraulic connection, a pressure controller (blue) anda shut-off valve (red).

Burster head

This is available in three sizes; 110, 140 and 200 mm diameter. When running, thehydraulic load extends the pistons, which exerts a force on the surrounding area.This will result in fractures. It is possible to run two to five burster heads from a singlehydraulic power unit.

200mm burster head

For detail, refer to the illustration and key which follows overleaf. The main componentsare the casing (3), the piston (4), and the two connection lines (1) and (2) for the high andlow pressure circuits respectively.



1020

265

130

200

430

135

130

200




1 2 3 4 10 5 11

9 8 7 6

Key Burster head

1 High pressure line 7 Piston sealing2 Low pressure line 8 O-ring3 Casing 9 O-ring4 Piston 10 Allen head screw5 Head 11 Oil wiper ring6 Sleeve

Wedge

This is made from hardened metal and is placed between the pistons and the outside ofthe hole in order to spread the load.

Wedge


Hydraulic hoses

For detail, refer to the illustration and key which follows. The high pressure hose has adouble shell. In the case of leakages, or even rupture of the inner shell (2), the hydraulicoil is retained by the outer shell (1). At the unit's connection side, the hydraulic hose isfitted with a screw-type hydraulic fitting (3). At the burster element's connection side, aplug-type hydraulic fitting (1) is located. These fittings need special care when in use.The plug-type fitting can be replaced by a screw-type fitting.

The fittings can be in-line or at 90˚.



1 2 3

Key Hose construction and fittings

1 Outer shell with plug-type fitting2 Double (inner) shell hose3 Screw-type fitting

In–line hose fitting 90˚ hose fitting


Drilling and installation

Holes are drilled into the structure, using a diamond drill bit, in a straight line or diamondgrid to achieve the desired bursting pattern. The holes are normally staggered, and setat intervals such that the concrete will fracture into manageable pieces. The holediameter required depends on the size of the burster head, which is generally either110mm or 200mm diameter. Where sections of concrete are to be removed there maybe parts of the structure that need to be left undisturbed. The preferred method ofdrilling, therefore, is to create a separation line using the appropriate diamond tools.

Note: The burster head must be installed into each hole in sequence. Care must betaken when inserting the head to ensure that the plane of movement of the pistonswill correspond with the intended rupture line.

Bursting operations 8.3


LL2L

6

min. L16

1 2 3

5 4

Key Example of a drilling pattern in a concrete structure

1 Steel reinforcement 4 Holes for burster head2 Separation line 5 Ideal rupture line3 Steel reinforcement L = Distance and depth of the separating line incisions

CORRECTWRONG

Ideal rupture line

Correct and incorrect burster head insertion

90˚

90o

Competence


The bursting process

Setting the valves

1. Set the control valve into position 0.

2. Ensure that the pressure controller is open.

3. Ensure that the shut-off valves for the connected high pressure circuits are open.

4. Ensure that the shut-off valves for the disconnected high pressure circuits are closed.

Starting the engine (petrol type)

1. Set the starter to ON.

2. Set the petrol shut-off valve to ON.

3. Actuate the choke (if necessary).

4. Set the throttle lever to the 1/2 position.

5. Activate the manual starter.

6. Gradually pull the starter handle until some resistance is felt, then pull it more strongly.

7. Gently release the starter handle, taking care that it does not bounce.

8. Adjust the throttle lever and, if necessary, switch off the choke.

9. Position the throttle lever to full acceleration.

Connecting the 3-phase supply unit

1. Connect the cable to the power supply.

2. Press the motor start button (located on the switch box).

3. Ensure that the fan rotation is correct.

4. Connect the hydraulic hoses to the burster head.



1

2

3

Hydraulic connectionsat the burster head

Key1 Tightening nut and washer2 Hydraulic supply3 Burster head connection

Noise and fumes


5. Connect the hydraulic hoses to the power pack.

Hydraulic connection to the power pack

6. Insert the burster head into each hole in sequence. Insert a metal wedge to retain thehead. The first 'burst' should be nearest to a free edge.

Inserting and wedging the burster head

7. Ensure all holes are of sufficient depth, and that the piston is located in the centreposition within the slab. This will ensure that the rupture lines are transverse to theline of the head and follow the 'ideal' line.

CORRECT WRONG

Correct and incorrect location of the burster head




8. Position the power pack, connect to the electrical supply and switch on. Ensure thatthe fan is running in the correct direction. If motor driven, position and operate inaccordance with safe working practices.

Switching on the power unit

9. Turn the pressure valves clockwise to build pressure to the head.

10. Set the pressure control valve to position 1 (BURST).

11. Slowly close the pressure controller.

12. Check the burster head piston-extend pressure gauge. The maximum permissiblepressure is 2000 bar.

Burster head piston-extend pressure gauge

13. Visually check the bursting process. As the pressure builds, the pistons extendoutwards and will induce cracking.

Pistons extending outwards as the hydraulic pressure increases




14. When the pistons are fully extended and the 'burst' has been achieved, switch thecontrol valve into position 0, and open the pressure controller in order to reducepressure to the burster head to zero.

Pistons are fully extended and the desired fracture achieved

15. Set the control valve to position II to retract the pistons.

16. Check the position indication at the pressure gauge. The maximum permissiblepressure is 150 bar.

17. Switch the control valve into position 0.

18. Insert additional wedges, if required, to further expand the concrete fracture,e.g. to facilitate the cutting of steel reinforcement using bolt croppers, angle grinderor oxyacetylene cutting equipment.

19. Remove the section of burst concrete to allow work on other areas to proceed.

Maintenance





Section 9 Crushing 9.0

129Section 9 Crushing© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




9.1 General 131


9.3 Crushing operations 136


9.1 State the purpose of a concrete crusher.

Explain briefly how the crusher unit is able to break concrete.

9.2 List some of the factors which influence selection of the appropriate crusher unit.

List the main component parts of the crusher unit.

State why the crusher body should not be modified in any way.

9.3 Explain how the distance between crusher points can be adjusted.

List the checks that should be made prior to operating the crusher.

List the key steps in operating the crusher.

Explain why the crusher is normally only operated by two operatives.




Introduction

Concrete crushers are used for low noise, vibration-freedemolition of concrete structures. A selection of machines isavailable, ranging from lightweight, single operator units tolarge, remotely controlled machine-mounted units.

Crushing differs from bursting in that it does not require diamondholes to be pre-drilled and the resulting rubble is of much smallerdimensions. Crushing machines have 'C' shaped jaws whichresemble a crab's claw. These are fitted over the concrete to beremoved. The crusher jaws are forced together under hydraulicpressure which causes the concrete to be crushed. The processis repeated over the whole area of concrete that is to beremoved. Pincers are used for spreading or cutting reinforcement.

In order to use a crusher, a clear edge must be available forthe jaws to engage onto. If there is no clear edge, this must becreated by sawing or drilling a separation line in the concrete.

Hydraulic power packs are used in conjunction with thecrusher unit. These can be electric, diesel or petrol powered.

Typical hand held crusher unit Typical machine mounted crusher unit

Typical hand held pincer

General 9.1


Full face shield



and skin


General

It is essential to select the correct type and specification ofequipment for a particular contract. Crusher units are availablehand held or machine mounted and the jaws can be of theclaw type or pincers. Selection will depend on the extent andnature of the crushing operations being undertaken. Whilst the different makes/modelsof concrete crusher will vary in their design, their function remains the same.

The body of the crusher is normally made from high-performance aluminum. Thisreduces the weight of the unit and makes it easier to handle. Typical specifications areshown below.

Hydraulic power pack

Hydraulic hoses carry hydraulic fluid to and from the machine pump to the operating tool.

Make connections to the crusher unit using the procedure on the next page.



Pincer – typical specification

Working pressure 700 bar

Pushing power of the piston 22.5 tonnes

Maximum power 5 tonnes

Maximum power at centre of handle 9 tonnes

Maximum cutting power in the centre 15 tonnes

Maximum cutting power at the notch 25 tonnes

Dimensions 770 x 210 x 170mm

Net weight 16.5kg

Maximum opening on front of lever 70mm

Maximum opening on front of cutting blades 270mm

Length of the cutting blades 130mm

Crusher (claw type) – typical specification

Maximum opening 315mm

Hydraulic power 30 tonnes

Power at the tip 13.6 tonnes

Working pressure 700 bar

Working time 10 seconds

Returning time 8 seconds

Dimensions 740 x 860 x 180mm

Net weight 52kg

Competence


1. Push together the two parts of the hose coupling so that they audibly lock into place.

2. Secure the connection by turning the locking ring on the coupling.

Note: Do not attempt to couple hoses when the unit is running or the hose isunder pressure.

3. Make the connection to the power pack by activating the pressure relief valve.

4. Set the pressure reducer on the coupling of the low pressure hose by screwing it inuntil the required pressure is achieved.

The power pack is petrol driven or is powered from a three-phase electricity supply.

Example of a portable power pack powered from a petrol engine



7

6

5

1

2

3

4

1 Petrol engine2 Relief valve3 Oil reservoir4 Oil cooler

5 Radial piston pump6 Fuel tank7 Trolley frame

Key


Example of a portable power pack fed from a three-phase electricity supply

Water supply

A water supply is required for cooling purposes. The water pressure should not exceed10 bar. If the supply pressure is greater than 10 bar, a pressure control valve will need tobe included in the line. Adjust the water flow at the supply tap. Do not shut off the watersupply tap during crusher operation, and never disconnect the supply when the unit isrunning or under pressure.



10

1

5

2

3

4

7

8

9

6

1 Electric motor2 Relief valve3 Oil reservoir4 Oil cooler5 Cooling water hose

6 Radial piston pump7 Trolley frame8 Secondary socket9 Power supply socket10 Control unit

Key


Crusher unit

An example of a crusher unit is shown below.

Example of a crusher unit

The crusher cylinder (1) houses the pistons which bear down on the crusher point (2).The fixed crusher point (4), which is mounted on the opposite side of the crusher body,can be adjusted using the separators/spacers (5). The crusher points incorporate a steeltip (3) which is pressed-in. The carrying device (8) is fixed to each side of the crusher body.

Note: The body of the crusher has been designed, built and tested to the highestengineering standards. Modifications, such as the fitting of additional handles,drilling holes in the body or engraving company names/numbers, must not becarried out as they may result in a reduction in strength.



9

8

7

6

1

2

3

4

5

Key1 Crusher cylinder2 Crusher point (hydraulically operated)3 Steel tip4 Crusher point (fixed)

5 Separators (spacers)6 Hoses7 Crusher body8 Carrying device9 Spool valve


Considerations prior to use

1. The crusher can weigh up to 45kg. Never lift or drag the unit by its hydraulic hoses.Always use the frame or carrying handles.

2. The power pack may require a flow of cooling water. If thisis the case, it must never be operated without it.

3. Reinforcing bar should be cut using an abrasive wheel orcutting torch, and may require a further operator.

4. Crushing equipment is normally designed for 24 hour operation. Site facilities andoperator levels need to match up to this requirement.

5. The crusher manufacturer's instructions should always be followed.

Setting the distance between crusher points (piston type)

Adjust the distance between crusher points to suit the concrete thickness. The tablebelow can be used as a guide. As an example, a wall of 225mm thickness requires75mm thickness of spacers (achieved by using a 50mm separator together with a25mm separator).

Crusher points adjustment table

E.g. for a 225mm concrete wall:

B = 105mm (distance between points with pistons extended)

A = 245mm (distance between points with pistons retracted)

Note: Select the intermediate ring on the right-hand side(for improved handling).

Crusher points retracted and extended

Crushing operations 9.3


Wall thickness Point thickness Requiredin mm in mm separations

Apistonretracted

320295270245

220205

Bpistonextended

180155130105

8065

300275250225

200120–175

No.

–1111221

Lengthin mm

–25505025505025

B

A

PPE




Inserting the spacers into the fixed crusher point

Refer to the illustration and key which follows.

1. Loosen the clamping screws (2).2. Withdraw the crusher point (1).3. Slide on the required number of spacers (3) and (4).4. Relocate the crusher point and tighten the clamping screws.

Checks required prior to operating the crusher unit

1. Inspect crusher points for damage.2. Examine the crusher body for distortion or cracks.3. Check the carrying device/handle for firm mounting and any damage.4. Check the spool valve and crusher cylinder for leakage.5. Inspect hydraulic connections/hoses and check that all connections are properly seated.6. Check the operation of the spool valve.7. Check that the relief valve is shut.8. Check and adjust water flow at the external water tap.

1 3 4 5

2

1 Crusher point2 Clamping screws3 Spacer (50mm)

4 Spacer (25mm)5 Shield

Key Spacer insertion


Operating the crusher

1. Two operatives must be available to work thecrusher at any one time. The only exception iswhen the unit is suspended by a crane (or otherapproved device).

2. Set the ON/OFF switch on the electric motorto position ON.

3. Position the crusher squarely, and at right angles,to the concrete. The crusher must never beoperated at an angle either diagonally or axially.

4. Ensure that there is a 40mm minimum gapbetween the concrete and the crusher bottom rim.

5. Set the spool valve to the 'Crushing' setting(upper position). This extends the crushercylinder.

6. Advance the crushing piston to the point whereit touches the concrete.

7. Stop the piston and check that the positionof the crusher is correct and that further pistonmovement will be safe.

8. Ensure that hands are away from the piston area.

9. Resume crushing, allowing the piston stroketo continue, taking care to check that thereis nothing trapped between the cylinder andthe crusher arms.

10. Set the spool valve to the 'Retract' setting(lower position). This retracts the crushercylinder.

11. Move the crusher along to the next positionand make another crushing operation followingthe steps above.

Note: The crusher can be forced off the concreteduring use ('kickback'), which can result inserious injury to the operator and damage tothe machine. The risk of kickback can beeliminated by following the steps above andalways using the crusher unit in strict accordance with the manufacturer's instructions.

Maintenance

Always follow the manufacturer’srecommendations. General guidance is given inSection 2.7 Maintenance of tools andequipment, pages 39 and 40.



1

3

4 40mm (minimum)

Effective riskcontrol



Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




10.1 General 141


10.3 Making joins in the wire using connectors 150

10.4 Sawing operations 158

Section 10 Wire sawing 10.0

139Section 10 Wire sawing© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


10.1 State the purpose of a diamond wire saw.

Explain briefly how the saw is able to cut concrete.

10.2 List some of the factors which influence selection of the appropriate wire saw.

List the main component parts of a diamond wire saw.

10.3 List the main types of connection which are used to join lengths of wire.

Understand the procedure for fitting each type of connector.

10.4 State the various preparatory checks that should be made prior to commencingsawing operations.

Explain the procedure for mounting the saw and rolls.

Explain why the direction of travel of the wire is important.

Explain what is meant by the 'grinding-in' process.

List the key steps in making a saw cut.

Explain how sawn concrete blocks can be safely removed.

10.5 List some common faults that can occur during sawing operations and thepossible solutions.




Introduction

A wire saw is essentially a diamond impregnated wire which isfed through a series of pulleys to produce a cut. The techniquewas originally developed to saw quarry stone but is ideal forcutting structural concrete. It can be used to cut structures ofany depth and shape. Because of this versatility, wire saws areoften used where other cutting methods are not practical.

A number of different designs of saw are in common usage butthere are two main types used in the drilling and sawingindustry. One type is mounted onto the surface of the concrete;the other is a self-contained design in which the drive rollers areincluded within the unit. The saw includes a feed motor, formoving the diamond wire storage rolls forwards or backwards,and a drive motor powering the diamond wire in order toproduce the cut. The motors can be hydraulically driven orpowered from an electrical supply.

The wire used is made from steel and is comprised of multiple strands. The length istypically around 6 metres. Diamond beads of 10mm diameter are spaced along thelength of the wire, set approximately 30mm apart. The beads are separated by smallsprings. These are made from plastic or rubber, depending on the type of wire and itsmanufacturer. The wire is positioned over the pulleys and fed through pre-drilled holes inthe concrete and then back over the drive pulley. It is joined using special crimps.

Sawing is carried out at a constant speed. Pressure is applied on the wire by steadilyexerting a gentle backward movement which extends the pulleys.

Typical wire saw

General 10.1




and skin


General

It is essential to select the correct type and specification ofequipment for a particular contract. Storage type wire saws areavailable which operate from separate or built-in power unitsand can have a single or multiple roll device. Special saws areavailable for making circular cuts or pipe cuts. Selection will depend on the extent andnature of diamond sawing operations being undertaken. Whilst the different makes/modelsof wire saw will vary in their design, their function remains the same.

Diamond wire saws

Storage wire saw (for direct mounting)

This is used on smaller contracts. Because it is direct-mounted, potentially hazardous,free-running lengths of diamond wire are avoided. The saw is used in conjunction with ahydraulic or three-phase electric power pack.



4

3

5

2

1

6 7

9

8

Key1 Chassis2 Diamond wire guard3 Drive roller assembly4 Clamping roll5 Diverter roll6 Swivel roll7 Diamond wire8 Saw mounted onto the concrete9 Free-wire protection device

Competence


Storage wire saw (with multiple roll device)

This is used for difficult cutting angles and geometries. With this type of saw the powerunit is built into the chassis. The power source can be hydraulic or a high frequencyelectrical supply.

Large storage wire saw

This is mainly used in civil undergroundengineering work. The high cuttingpower and large diamond wire storage(up to 60m) make the machine ideal forlarge scale operations.



2

3

8

7

6

5

3 4

9

10

11

14

13

12

Key1 Protective hood2 Drive motor3 Diverter roll4 Swivel roll

5 Clamp6 Diverter roll assembly7 Drive roll assembly8 Chassis and handle

9 Crane hook10 Rocker11 Guide roll

(for wire storage)

12 Wheel13 Storage compartment

(for clamping elements)14 Folding work bench

1


Circular wire saw

This is used for making circularand curved cuts. The cuttingradius is adjustable.

Key

1 Diamond wire2 Drive motor3 Feed motor4 Worm gear5 Drive roll with wire guard6 Diverter roll7 Clamping roll8 Extension arm9 Central tube10 Swivel support11 Wire tensioner12 Water feed line13 Wire guard14 Curved cut



2

5

1311

10

9

78

16

12 3

4

14


Pipe cutting diamond wire saw

This is used for making straight and angled cuts into concrete pipes.

Main components

Diverter rollers

These function as guides for the diamond wire.



2 6 5

15

2 1 10

7 17

12

14

9

8

162

13

2 11 3 4

Key1 Drive roll2 Diverter roll3 Rotating chassis4 Swivel support5 Central yoke

6 Yoke centre piece7 Swivel yoke8 Control box9 Hydraulic unit10 Swivel pipe11 Laser pin

12 Wire tensioner13 Diamond wire14 Water nozzle15 Swivel yoke angle stop16 Cylinder17 Concrete pipe


Supports

These support the wire rollers and wire roll combinations.

Diamond wire guard

This prevents accidental contact with thecutting tool and will intercept any loose orbroken equipment parts. It also functionsas a spray guard.

Water lances

These are required to convey water tothe cut.

Motors

The drive and feed motors can be hydraulicor powered from an electrical supply.Hydraulically powered motors produce ahigher output.

Power pack

This is required when using a mountedwire saw.



1 2 3

Key 1 Support with clamping spindle securing2 Support with support roll pair3 Support with distancing diverter roll

Wire guard

Water lance


The diamond wire

Types

There are two types of diamond wire:

• sintered diamond wire (11mm diameter)

• galvanic diamond wire (10mm diameter).

Sintered diamond wire

On this type of wire the diamonds are sintered onto the wire during manufacture.

On first using, the length of diamond wire must be given approximately one turnanticlockwise per metre length. Refer to the following table. The precise turningrequirements, however, may vary depending on the manufacturer. Always check the wiremanufacturer's use instructions.

The turns should be changed after each cut. In order to ensure even wear on thediamond beads, vary the number of turns each time (±30%). However, the number ofturns must not be less than one per metre.

If the diamond wire begins to run in too smooth a line, then the frequency of turning willneed to be significantly increased, e.g. by a factor of 2 or 4, in order to achieve therequired cutting efficiency.



1 2 3 4 5 6 Key1 Plastic sheathing2 Steel core3 Diamond grains (multi-layer)4 Sintered bonding5 Steel spring (flat)6 Steel wire(braking load 19000N approx.)

Length of diamond wire (m) Total number of turns required

5.0 5 – 67.5 8 – 1010.0 11 – 1315.0 16 – 18


Example of turning frequency for a 10m sintered wire:

Galvanic diamond wire

On this type of wire the diamonds are attached to the wire by galvanic action.

On first using, the wire must be given a half-turn anticlockwise (approximately) per metrelength. Refer to the following table. The precise turning requirements, however, may varydepending on the manufacturer. Always check the wire manufacturer's use instructions.

The turns should be changed after each cut. In order to ensure even wear on thediamond beads, vary the number of turns each time (±30%). However, the number ofturns must not be less than 0.5, or more than 1.5, per metre of diamond wire.

If the diamond wire begins to run in too smooth a line, then the frequency of turning willneed to be significantly increased, e.g. by a factor of 2 or 4, in order to achieve therequired cutting efficiency.



Following the 1st cut Additional 3 turns

Following the 2nd cut Additional 3 turns

Following the 3rd cut Additional 3 turns then release

Following the 4th cut Additional 3 turns

Following the 5th cut Additional 3 turns then release, etc.

1 2 3 4 5 6 Key1 Plastic sheathing2 Steel core3 Diamond grains (single-layer)4 Galvanic bonding5 Round steel spring6 Steel wire(braking load 19000N approx.)

Length of diamond wire (m) Total number of turns required

5.0 2.57.5 410.0 515.0 8


Example of turning frequency for a 10m galvanic wire:



Following the 1st cut Additional 2 turns

Following the 2nd cut Additional 2 turns

Following the 3rd cut Additional 2 turns then release

Following the 4th cut Additional 2 turns

Following the 5th cut Additional 2 turns then release, etc.


Introduction

Sintered diamond wire reduces in diameter as it wears whereas galvanic diamond wiredoes not. Therefore, it is only when joining lengths of sintered diamond wire that the wirediameter needs to be taken into account.

Both types of wire can be joined (or repaired) using a hinged connector, screwconnector, or repair sleeve. The latter two methods, however, should only be used withlarge diameter wire (300mm minimum).

Note: Do not join lengths of worn diamond wire where the respective diameters differ bymore than 0.2mm.

Connector installation tools

Various tools will be required. These include:

• universal pliers

• cutter

• pipe wrench (for the screw connector)

• angle grinder.

Cutting the diamond wire

The diamond wire will need to be cut before any connections can be made.The procedure is as follows.

1. Make a clean and straight cut in the diamond wire using a cutting-off wheel.

2. Remove the steel spring using a pair of universal pliers.

3. Separate the steel wire from the plastic sheathing using a suitable cutter.

Making joins in the wire using connectors 10.3


Work equipmentconsiderations


Using hinged connectors

This type of connector employs a hinge mechanism.

Hinged connector

Connections are made using the following procedure.

1. Cut the diamond wire so that the hinged connector comes to rest directly at thebeads (both to the left and the right).



1 3 1

5

4 2 4

Key1 Connector fork

4 Pressing tool stop5 Mounted hinged connector

2 Articulation3 Hinge pins

12mm 10mm

9mm 9mm

Correct cutting of the diamond wire


2. Insert the connector fork (3), with groves in the direction of the pressing (1), into thepress insert (2) as far as the stop (4). Gently clamp with the press tongs.

Inserting and clamping

3. Insert the end of bare wire into the hole.

Inserting the wire

4. Ensure that a small gap of between 0.5 and 1mm is visible. This gap will allow theconnector to expand during the pressing process.

5. Press the wire into connector fork. The pressed dimension at the connector pieceshould not exceed 7.8mm.

Expansion gap and maximum pressed dimension



2

1

3

3

4

Key1 Pressing direction2 Press insert

3 Connector fork4 Stop for pressing tool

0.5 – 1mm

Max.7.8mm


6. Press the second connector fork (with pre-fitted articulation) into place in the sameway as for the first connector piece.

Open and close the hinged connector using the following procedures, making referenceto the illustration below.

Opening and closing the connector

To close:

1. Turn the wire in an anticlockwise direction.

2. Join the two connector pieces using the pin (flat side forward).

3. Drive the pin fully into the hole using the mounting device.

To open:

1. Place the connector in the rest below the ejector spindle of the mounting device.Align it in such a way that the pin can be pushed into the groove behind the rest.

2. Eject the pin by turning the spindle.

3. Re-connect the diamond wire using the same connector and a replacement pin.



3

2 3

1

Key1 Connector support2 Hinged connector3 Spindle


Using repair connectors

This type of connector is used when the diamond wire breaks.

Repair connector

Before fitting the repair connector, a rubber sealing ring must be located to maintainflexibility around the cutting point.

Locating the sealing ring



2 1

32

Key1 Repair sleeve2 Stop for pressing tool3 Fitted repair sleeve

13mm 12mm

10mm 10mm

Rubber sealing ring



1. Insert the repair sleeve (3) onto the press insert (2) as far as the stop (4). Gently clampwith the press tongs.


2. Insert the end of bare wire, together with the pre-fitted rubber ring, into the hole.

Inserting the wire

3. Press the wire into the connector fork. The pressed dimension at the connector pieceshould not exceed 7.8mm.

Minimum pressed dimension

4. Press in the other side of the repair sleeve in the same way as the first.



2

1

3

3 4

Max.7.8mm

Key1 Pressing direction2 Press insert

3 Repair sleeve4 Stop for pressing tool


Using the screw connector

This type of connector has male and female components that connect together bymeans of a threaded stem.

Screw connector

Before fitting the screw connector, a rubber sealing ring must be located to maintainflexibility around the cutting point.

Locating the sealing ring



1 2

43

1 Male connector2 Female connector3 Threaded stem4 Mounted screw connector

13mm 12mm

10mm 10mm

Rubber sealing ring



1. Insert the male connector (3) into the press insert (2) so that the projection is 1mm.Gently clamp with the press tongs. The pressing contact area is indicated on theconnector pieces by a recess (4).


2. Insert the end of bare wire, together with pre-fitted rubber ring, in the hole.

Note: The threaded stem must always point in the direction of travel of the diamondwire, as depicted by the direction arrow on the wire (5).

Inserting the wire

3. Press the wire into the connector fork. The pressed dimension at the connector pieceshould not exceed 7.8mm.

Minimum pressed dimension

4. Press the female part of the connector in the same way as the male connector.



Key1 Pressing direction

2 Press insert

3 Threaded connectormale part

4 Recess

2

1

3

3

41mm

5

Max.7.8mm


Checking the sawing equipment

The saw should be checked prior to use to ensure that it isfree of defects. Always follow the guidance given in themanufacturer's instructions.

Preparatory

Before starting work, all danger areas must be secured andappropriate barriers and signs erected.

The parts of the structure to be sawn are normally marked outby the customer. It is necessary to determine the maximumweight of concrete structure that can be sawn, bearing in mindthe conditions on site and the services available, e.g. thecrane/lifting device must be adequate for the loads to be lifted.The weight of the structure to be cut out should not exceed themaximum permitted floor loading (1m3 of concrete weighs2,400 – 2,700kg). The structure must be correctly secured froma structural engineering perspective, i.e. the cut structuralblocks must not be liable to displacement by over-turning orfalling out/down.

The various anchoring holes need to be marked, e.g. for mounting the diverter rollsupports and for securing the load hooks (for removal of the structural blocks after cutting).

The order of cuts is important to ensure that the tool does not jam during sawingoperations and that the structural blocks can be subsequently removed without problems.When deciding on the sequence of cuts, full account must be taken of personal safetyissues. The normal sequence for cutting an opening in a wall is to cut out the bottomfirst, followed by the side and lastly the top.

If slightly conical cuts are made, the direction of removal must be taken into accountprior to sawing.

Taking account of the direction of removal



Work equipmentconsiderations

Danger topassers-by

Protection zonearound work area


It is necessary to round off sharp edges and corners using suitable means i.e. rotary drillfitted with a chisel attachment, or a hammer and chisel. This will minimise the risk ofresultant wire breaks.

Rounding off sharp corners

Mounting the saw and rolls

1. Position the saw so as to minimise the free lengths of diamond wire.

2. Secure the saw to the surface, ensuring that it is completely stable.

Note: When securing the saw and the roll supports, anchoring elements that areappropriate for the sub-surface must be used. When positioning the dowels,the dowel manufacturer's installation instructions must be followed.

3. Ensure that the diverter rolls are aligned in the precise direction of the cut. It isimportant to select the largest possible diameter diverter rolls (200mm minimum).Smaller diameter rolls will result in an increase in wire breaks in the vicinity ofconnections.

4. It is essential to position diverter rolls at the inlet and outlet points in order to gatherthe diamond wire at the end of cutting.

5. Select the angle of arc (of the wire) to be as high as possible in the drive wheel. Thiswill avoid the risk of the wire slipping through. The minimum arc should be 50% of thewheel circumference. Also, if the contact arc of the wire is insufficient, this will result inan increase in the number of wire breaks and increased wear.

Positioning the wire

1. Note the direction of travel (the direction arrow is located behind the beads).

2. When using wires with a small diameter, mount the conically worn beads towardsthe front.

3. The direction of travel of the wire should not be changed, as this wil result insignificantly increased wear.




4. Determine the diamond wire length, taking into account the machine specification.

5. Turn the diamond wire the required number of twists.

6. Connect the diamond wire as specified in the wire saw operating instructions.

Making the connections

1. Connect the drive unit to the diamond wire saw. If a hydraulic motor is being used,ensure that the correct connections are made for that specification of motor and thatforward and reverse connections are created.

2. Connect the drive assemblies to the power connection.

3. Install the cooling water supply to the cutting tool.

Note: In order to ensure adequate cooling and flushing of the diamond wire, the driverolls, as well as the entry points of the diamond wire in the cut, must be sprayedcontinuously with water during cutting operations. Adequate flushing with waterwill significantly extend the lifetime of the saw.

4. Ensure that the water pressure is in the range 1 – 6 bar, and the water temperature isnot higher than 25ºC.

Note: All necessary precautions should be taken to avoid risks of the water freezing incold weather, e.g. ensure that there is sufficient anti-freeze included.

5. Position the water lances so as to give an effective spray at the point of cutting.

Grinding-in (pulling) the wire over the structure

1. During grinding-in, ensure that there are no hoses or cables in the vicinity of the wireor which might come to rest near the wire during sawing operations.

Note: If the diamond wire cannot be manually pulled over the building structure, it willnot start to run under machine power either.

Sawing

1. Start the saw at low wire tension to avoid jamming.

2. Adjust the wire (cutting) speed to fall in the range 20 – 25 metres/second. If there is asignificant amount of reinforcement in the concrete, the speed should be reduced to18 metres/second.

3. Maintain the feed pressure during cutting at 80 – 160 bar.

Note: The optimum pressure level will depend on the contact length of the wire.Excessive pressure will lead to increased, or unilateral, wear on the diamond beads.




4. Reduce the pressure when sawing concrete of 80mm thicknesses or less, and alsowhen making circular cuts.

5. When cutting operations are paused or interrupted, leave the diamond wire in the cutfor a few moments without feeding. This will make subsequent start-up easier.

6. Switch-off the saw when cutting work is complete and secure the controls againstunintentional start-up.

7. Shut-off the water feed.

8. Disconnect the various supply lines and dismantle the saw.

Removing the sawn structural blocks

1. Select a suspension device which is appropriate for the size and weight of concreteblocks to be removed.

Note: The removal of structural blocks is a potentially dangerous operation andparticular care must be exercised and appropriate precautions taken,e.g. no personnel in the danger areas, cranes adequate for the load to be held/lifted.

Example of a suspension device Suspension connections



1 2

Key1 25 tonne suspension device2 4.0 tonne suspension device

570mm


2. Once the structural blocks have been removed, cover and structurally secure anylarge floor/ceiling cut openings by installing props and supports.

Structurally securing large cut openings

3. Install barriers around any exposed floor/ceiling openings.

Installing safety barrier

Disposing of sawing sludge

1. Dispose of sludge in accordance with local environmentalregulations. The sludge contains fragments of the variousmaterials that have been sawn together with residue fromthe diamond wire tool.

2. Create a water barrier to collect and recycle the water.Use an approved system such as that based on a unitarycomponent, polyurethane filling and assembly foam.

3. Draw-off the water using a suitable extractor and filter. Then pump it back into thewater circuit for recycling.



Protect theenvironment


Troubleshooting

The following table gives guidance on common faults that occur during sawing operations,their likely cause and possible solutions.

Troubleshooting and maintenance 10.5


Fault Possible cause Solution

Saw cuts very slowly or not Very hard aggregate Sharpen diamond wire and/orat all reduce the wire speed

Excessive contact length Reduce contact length andreposition the diverter rolls

Wire speed too high Reduce the speed

Wire cuts on all sides of the Take account of taut and slackmaterial to be cut sides during mounting

Unilateral diamond wire wear Wire inadequately turned Turn wire tighter

Insufficient water Increase water feed

Excessive pull on the wire Reduce feed pressure

Insufficient clearance between drive Increase clearancewheel and the material to be cut

Diverter rolls sit at an angle and Correct the alignment of thediamond wire is prevented from diverter rolls with the wireturning by the roll edges (or alignment line)

Diamond wire breaks at the Excessive pull on the diamond wire Reduce feed pressureconnector

Excessively sharp edges Break edges and positiondiverter rolls

Excessive wear at connector Increase cooling water feed

Excessively tight arc (radius) Position diverter rolls

Diamond wire vibrates heavily Ensure short, free wire lengths

Heavy wear at connector and/or Mount connector as specifiedincorrect mounting

Diamond wire breaks behind Excessive pull on the diamond wire Reduce feed pressurethe connector

Excessively sharp edges Break edges and position diverterrolls

Excessively tight arc (radius) Mount diverter rolls

Traction wire vibrates heavily Check wire for even diameter andreduce speed

Connector incorrectly pressed Press connector as specified

Diamond wire motor does Excessive pull on the wire Reduce feed pressurenot run

Sharp edges Break edges, set diverter rollsand manually grind-in the wire

Diamond wire has varying thickness Check wire for even diameter(tolerance +/- 0.2mm)

Wire connector pieces too tight Check diamond wire connector fitting

New wire in an old, narrower cut Use worn diamond wire with asmaller diameter

Excessively long arcs in the material Mount more diverter rollsto be cut




Wire frequently jumps from Inadequate wire tensioning Increase feed pressuredrive rolls

Rolls are not in the line with the Correct the alignment of thediamond wire diverter rolls with the wire

(or alignment line)

Kinks present in the wire Align and straighten the wire(be careful as the wire may bedamaged)

Angle of arc too tight Increase the angle of arc usingfurther diverter rolls

Diamond wire cuts on all sides of Take account of taut and slackthe material to be cut sides during mounting

Wire frequently jumps from Inadequate wire tensioning Increase the feed pressurediverter rolls

Rolls are not in alignment with the Correct the alignment of thewire diverter rolls with the wire

(or alignment line)

Kinks present in the diamond wire Align and straighten the wire

Vibrations due to excessive Mount diverter rollsclearance between drive wheel andthe material to be cut

Angle of arc too tight Increase the angle of arc

Rapid and strong wire vibration Excessive diamond wire tensioning Reduce feed pressure

Excessively long arc sections Mount more diverter rolls

Sharp edges or reinforcement Break edges and position diverterrolls

Excessive speed Reduce speed of the drive wheel

Wire continues to 'hang' Connectors too thick and/or varying Check wire and connectors forin the cut wire thickness uniform diameter

Material to be cut is not in wedges Wedge the material to be cut

Insufficient water Increase the water feed

Plastic heats up and 'telescopes' Increase water quantity andtogether pressure, and check the water feed

Diamond beads and plastic Increase water quantity and'telescope' together pressure

Diamond wire slips on the Inadequate wire tensioning Reduce the feed pressuredrive wheel

Excessively long arc in material Mount more diverter rollsto be cut

Bandage of drive wheel is worn Replace rubber bandage

Edges on the building structures Grind-in the wire

Inadequate arc at drive wheel Increase angle of arc by increasingsize of diverter rolls

Wire cuts on all sides of the material Take account of taut and slackto be cut sides during mounting


The rolls jam Check rolls and bearings

Loose drive connections Check drive

Wire cuts on all sides of the material Take account of taut and slackto be cut sides during mounting

Diamond wire motor doesnot run (cont.)





Cutting untrue Insufficient diverter rolls Mount more diverter rolls using(cut not straight) alignment wire and bubble level

Inadequate wire tensioning Increase feed pressure

Diverter rolls not fixed or not in Modify and ensure accuratealignment during the cutting process alignment and the secure fixing

of diverter rolls

Wire beads 'telescope' Plastic heating up due to Introduce more cooling watertogether insufficient water into the cut

Excessive pull on the wire Reduce feed pressure

Heating due to the wire slipping on Increase the wire tensioningdrive wheel

Whiplash effect when the wire Prevent whiplash effects by usingbreaks rolls or interception devices, e.g.

boards and sheet metal

Sudden jamming in the cut Wedge material to be cut

Reinforcements are loose Remove the loose reinforcements

Wire is pulled out of its press Tongs incorrectly adjusted and/or Check the pressing and theconnection inadequate pressing force tongs setting

Wire section through the connector Refer to the connector mountingtoo short instructions

Excessive wire tensioning and/or Reduce the feed pressureexcessive vibration

Thread of screw connector Thread crushed during pressing Press threaded connector asdoes not fit specified in the mounting

instructions

Dirty thread Remove dirt/cutting sludge

Diverter rolls becoming Mounted with excessively long lever Ensure short lever travel whendistorted mounting diverter

Supports not screwed tight Mount supports securely

Excessive wire tensioning Reduce feed pressure

Kinks in the diamond wire Whiplash effect when the wire Use rolls or interception devices,breaks e.g. boards and sheet metal

Small kinks caused when turning Avoid tight turnsthe wire

Wire loops not removed Do not pull the wire loops –(only tightened) remove them by turning

Wire runs slowly and remains Excessive diamond wire tensioning Reduce feed pressurein the same place

Excessively long arc sections Mount more diverter rolls

Very soft material to be cut Increase angle of the arc byincreasing the size of diverter rolls


Maintenance

The wire saw is a specialist cutting machine and must bemaintained strictly in accordance with the manufacturer'sinstructions. The following table is for guidance only and givesa broad outline of the schedule required.



Overall system Visual check X X X

Clean X

Hydraulic system Hydraulic hose inspection(tightness/cleanliness) X X X X

Note: for driver units refer to the Coupling inspectionspecific operating instructions (tightness/cleanliness) X X X X

Water economy Water line (tightness/cleanliness) X X X X

Blow out water (frost hazard) X

Water nozzles and feed hoses/cable Clean X

Note: for control unit refer to the Inspection Xspecific operating instructions

Cutting tool (diamond wire) Inspection X X

Change X

Accessible nuts and bolts Retighten X

Flange Clean X

Change X

Toothed belt/toothed wheels (oil) Inspection X X X X

Change X X

Major service X

Beforeeachstart-up

Uponcompletionofwork

Weekly

Annually

Intheeventofmalfunction

Intheeventofdamage

Competence

General guidance is on maintenance is given in Section 2.7 Maintenance of tools andequipment, pages 39 and 40.



11.1 Standards – general workmanship 169

11.2 Safety 170

11.3 Industry guidance 171

Section 11 Standards, regulations & guidance docu- 11.0

167Section 11 Standards, regulations and guidance documents© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139




11.1 List the main European/UK Standards which relate to working on concretestructures using diamond drilling, sawing, cutting, splitting and crushing equipment.

11.2 Have a knowledge of the safety documentation relating to working with concretestructures and an appreciation of where to find specific safety guidance.

11.3 List the main sources of industry guidance.




Standards – general workmanship 11.1


European/UK Standards

• BS 4019 – Rotary core drilling equipment. Specification for wireline diamonddrilling equipment.

• BS 673 – Specification for shanks for pneumatic tools and fitting dimensions ofchuck bushings.

• BS 4656 – Accuracy of machine tools and methods of test. Drilling machines.

• BS EN ISO 6807 – Rubber hoses and hose assemblies for rotary drilling andvibration applications. Specifications.

• BS EN 28662-5 – Hand-held portable power tools. Measurement of vibrations atthe handle. Pavement breakers and hammers for construction work.

• BS 5228-1 – Noise and vibration control on construction and open sites. Code ofpractice for basic information and procedures for noise and vibration control.

• BS 8000 – Workmanship on building sites. Code of practice for concrete work.Sitework with in situ and precast concrete.

• BS EN 60745 – Hand-held motor-operated electric tools. Safety. Particularrequirements for concrete vibrators.

• BS 6916 – Chain saws.

• BS EN 381 – Protective clothing for users of hand-held chain saws.

• BS ISO 6104 – Superabrasive products. Rotating grinding tools with diamond orcubic boron nitride. General survey, designation and multilingual nomenclature.

• BS ISO 22917 – Superabrasives. Limit deviations and run out tolerances forgrinding wheels with diamond or cubic boron nitride.

• BS ISO 3070 – Test conditions for boring and milling machines with horizontalspindle. Testing of the accuracy.

• BS ISO 3686 – Test conditions for high accuracy turret and single spindlecoordinate drilling and boring machines with table of fixed height with verticalspindle. Testing of the accuracy.

• BS EN 10244 – Steel wire and wire products.

• BS EN 13236 – Safety Requirements for Superabrasives


Publications

• A code of safe working practice for drilling and sawing operations– Published by the Drilling and Sawing Association (contact details overleaf).

• Noise At Work: Guidance For Employers – Publication Number INDG 362

• Dust Control On Concrete Cutting Saws Used In The Construction Industry– Publication Number CIS 54

• Protecting The Public: Your Next Move – Publication Number HSG 151

• Keep Your Mask On – Publication Number INDG 255

• Construction Silica – Publication Number CN2

• COSHH Essentials In Construction – Publication Number Silica CN3

• HAV – Publication Number INDG 175

• Short Guide To The Personal Protective Equipment At Work Regulations 1992– Publication Number INDG 174

• Working At Height – Publication Number INDG 401

• Getting To Grips With Manual Handling – Publication Number INDG 143

• COSHH – Publication Number INDG 136

• Stone Dust And You – Publication Number INDG 315

• Selection, Use And Maintenance Of Respiratory Protective Equipment– Publication Number HSG 53

• Dust Control On Concrete Cutting Saws HSE – Construction InformationSheet No.54

• Tower Scaffolds – Construction Information Sheet No.10

• Cement – Construction Information Sheet No.26

• Lone Workers – Publication Number INDG 73

• Guide To Power – Publication Number INDG 291

• Using Work Equipment Safely – Publication Number INDG 229

• Noise – Publication Number INDG 363

• Safety In The Use Of Abrasive Wheels – Publication Number HSG17

• Safe Work In Confined Spaces – Publication Number INDG 258

Safety 11.2



Associations

The Drilling and Sawing AssociationNorth Mill, Bridgefoot, Belper, Derbyshire DE56 1YD

Tel: 01773 820000

Email: [email protected]

Web: www.drillandsaw.org.uk

British Abrasives Federation (BAF)

Tel: 08456 121380

Email: [email protected]

Web: www.thebaf.org.uk

Publications

BSi Publications

Tel: 0845 0809000 (Helpline)

Web: www.bsonline.bsi-global.com

Health & Safety Executive (HSE) Books

Tel: 01787 881165 (Order line)

Web: www.hsebooks.com

Construction Industry Publications

Tel: 0870 0784400

Web: www.cip-books.com

Sources of industry guidance 11.3



12.0 Glossary of terms 173


Notes to trainers 2

1 Introduction 14



4 Hand sawing 54


6 Floor sawing 93


8 Bursting 117

9 Crushing 129

10 Wire sawing 139



Section 12 Glossary of terms 12.0

172Section 12 Glossary of terms© Construction Industry Training Board 2007Specialist Concrete Operations CTP 143/D


Glossary of terms 12.0


Aggregate Stone, rock, etc. used in the mix for producing concrete.

Arbor Centre section (hole) in blade into which the motor shaft fits.

Bowser Container, generally transported on wheels, containingliquid/water for use in the cutting process.

Braze (brazing) Soldering of a segment to a core/blade.

Bursting (bursters) Pressure applied by a cylinder to expand concrete so as toform fractures.

Carborundum disc Abrasive wheel, made of compressed particles, which is usedto cut or grind.

Concrete (fresh/green) Concrete in the process of curing.

Controlled demolition Breaking of concrete structures using diamond drilling, sawing,crushing or bursting equipment.

Crimp (crimping) Connection of two wires.

Crushing Force applied to concrete structure to reduce its size by acompressing effect in order to form fractures.

Diverter (roll) Guide rolls for the diamond wire.

Electroplate Coat with a layer of metal by means of electrolysis.

Galvanic wire Wire that has been galvanised.

Galvanise Coating with zinc to prevent rust.

Gearing worm Mechanism to rotate in a forward or reverse motion.

Grinding-in Hand pulling the wire to produce a groove to assist in keeping(the diamond wire) the wire in position.

Gullets Slots located between the blade blank and segment – used toassist the operation of the cutting blade.

Gyro effect Where the force of rotation affects the movement of theoperator/machine.

Hydraulic system A system powered by hydraulic oil.

Kickback When a blade snags in a cut, the blade is forced in thedirection of rotation.


Glossary of terms 12.0


Laser welding Method of fixing segments to a blade by laser using hightemperatures.

LED Light Emitting Diode.

Manual handling Lifting and moving materials using human effort rather thanmechanical means.

Masonry Cement-based building material.

Method statement Designed method of working.

m Metre(s).

m2 Metre squared – square metre(s).

m3 Metre cubed – cubic metre(s).(Concrete is ordered by the cubic metre and 1m3 = 1,000 litres.)

mm Millimetre(s).

PAT testing Portable Appliance Testing required in order to comply withThe Electricity of Work Regulations.

Permit to work Document giving permission to work in a sensitive/restricted area.

Pinching Action of clamping the blade between the sides of the cutmaterial.

Pneumatic system A system powered by air.

Power box Unit used to produce power/torque to other items ofplant/equipment.

Record sheet Document detailing work-related evidence.

Sinter(ed) Technique is used for fixing segments by applying heatand pressure.

Slurry (sludge) Residue produced by the cutting/grinding of materials.

Thermal lancing Used to cut construction materials using a process whereoxygen is forced through a metal tube filled with iron rods,generating high temperatures and melting the material it makescontact with.

Torque Movement causing rotation.

Undercut (protection) Blade includes additional segments to reduce wear on thesteel centre.


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