Demolition handbook EN - Inicio - · PDF filemethod is usually used for small demolition...

D E M O L I T I O N W I T H B R O K K

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Demolitionwith

Brokk

A H A N D B O O K


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Contents

Introduction .............................................................................................................................. 5

1. Demolition volumes ........................................................................................................ 6

2. General factors influencing method selection .................................................... 7

3. Preparing for demolition ......................................................................................... 8-9

4. Demolition methods and equipment ............................................................ 10-13

5. Capacities and costs ............................................................................................ 14-19

6. Partial demolition and reconstruction demolition ................................. 20-21

7. Demolition with Brokk ....................................................................................... 22-27

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The following companies have contributed to“Demolition with Brokk”:

Pauli Hietala, Borrkompaniet AB

Kjell Larsson, Kellek Konsult

Håkan Karlsson, Riviära AB

Mikael Hedlund, Rivteknik Industri RI ABLasse Eriksson, Södertälje Borrteknik AB

*

ton = metric ton

1 kg = 2,205 lb

1 m = 3,28 ft

1 m2 = 10,764 ft2

1 m3 = 35,315 ft3

Measurement conversion

Measures


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Demolishing a building or parts of it, is very oftenmuch more complicated and considerably moreexpensive than erecting it in the first place.

Everybody working in the demolition businesstoday is aware of this and the endeavour to findnew working methods, tools and machines to fa-cilitate the work of demolition is a constantlyongoing process. This handbook starts off by de-scribing demolition in general terms but it ismainly about demolition using Brokk - the remotecontrolled, electrically powered demolition ma-chine that gives contractors new opportunities todemolish profitably. The book is meant to be an in-spiration for present and future Brokk users. It isalso intended as specialized reading for majorcustomers who procure demolition contracts.

Since the 1970s Brokk AB has been developing,manufacturing and marketing Brokk machines.This is the company’s sole product line, one thathas of course been developed over the years andnow comprises a complete model programmewith a large range of attachments.

Attention is being increasingly focused on theenvironmental aspects of demolition work andnew demands are consequently being made ofdemolition contractors. Opting for the Brokkmethod of demolition not only greatly improvesthe chances of meeting the requirements that ap-ply to the individual operator’s work situation andthe general environment of the work place, it also

makes it possible to satisfy requirements for noisereduction, recycling etc.

In a nutshell - Brokk is a machine that enablescontractors to demolish cost effectively in accord-ance with their customers’ requirements and forthe successful development of their own compa-nies.

»Demolition with Brokk« is based on a previouspublication, »Demolition Handbook«, publishedby Atlas Copco in the mid 1980s. A work group atBrokk AB has been responsible for this and anumber of customers have contributed their expe-rience and opinions.*

We would naturally like to extend our warmestthanks to all those who have participated. Therapid development of demolition methods and ourproducts would be impossible without the closecooperation of our customers, the Brokk users.

Martin Johansson, Managing Directorof Brokk ABSkellefteå, March 2000

Introduction


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Demolition volumesReasons for the substantial increases in demolitionvolumes are:

• existing land within built-up areas must beutilized;

• demands for modernization and improvedcomfort;

• redevelopment of inner city areas;• rapid technological changes within industry

require ever more efficient plantpremises and this necessitates at least partialdemolition;

• technological equipment is being renewedeven more rapidly to maintain highly com-petitive levels and premises must be adapted.

The consequences of the above will be increaseddemands for the further technological develop-ment of demolition methods and equipment andtheir levels of efficiency.

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General factors influencingmethod selection

A range of different factors influence the choice ofdemolition method or combination of methods:• the location of the premises to be demolished• the surrounding area• the foundations or ground conditions• the amount of work space available• the existence of local statutes and restrictions• existing environmental requirements

Description of the premises• structural characteristics of the building -

special stress factors• construction materials used• condition of the building - age, wear and

tear, etc.• specific accident risks

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Demolition volume• What type of equipment will result in the

lowest total cost?• What is the time allocated for completion?

1) High capacity equipment - high hourlycost

2) Lower capacity equipment - lower hourlycost

If the conditions of contract for demolition areclearly specified, this often results in certain re-strictions in the selection of methods.

In the case of less specified demolition work,where various methods are allowed, it is moredifficult to carry out cost comparisons.


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3GeneralThoroughly inspect the premises, site, surround-ings, structural characteristics and neighbouringbuildings that could be affected by the intendeddemolition work. Investigate the environmentalrequirements/restrictions that apply and whetherthere is any potential risk to life and property.

Roofed and framed structuresCheck the stability of roofs and framed structures.Load bearing sections must be identified for rea-sons of safety.

WallsCheck the thickness of all walls and identify thosethat are load bearing.

Balconies etc.Check their system of support.

Concrete structuresCheck the type of concrete that has been used, itsquality and the extent of any damage.

Pre-stressed concrete and pre-caststructuresThese must be inspected with great care and atten-tion. You will require:• the necessary data from the manufacturer,• the necessary data from the building contractor,• the necessary data from the Local Authority• inspection by a Chartered Engineer• identification of the type of pre-stressing to be

used

Preparing for demolition

Cellars, wells, etcInspect these thoroughly and pay particular atten-tion to the possible presence of chemical fluids orgases.

Building materialsIf asbestos has been used special measures mustbe taken.Mains and services to be cut off:• electricity lines• gas pipes• telephone cables• fuel lines• water mains• heating lines

The demolition contractor shall always use sepa-rate service lines. When carrying out demolitionwork with Brokk check that the electricity supplyhas sufficient amperage.

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WasteIf residual waste on the site incurs a risk of infec-tion contact the appropriate Local Authority de-partment.

Previous function of condemnedpremisesIf you suspect the presence of dangerous gases orchemicals contact the Local Authority. This ap-plies particularly to radioactive waste.

Materials and equipmentCheck all materials and equipment to be used.

Scaffolding and shoresComply with all existing regulations. Scaffoldingshould be dismantled as demolition progressesand should not be allowed to reach above theworking level. All scaffolding shall be inspected.

Prohibited or restricted accessThis is the responsibility of the Local Authority.

Administrative aspectsA demolition project involves a large number oflocal and central government authorities (laws andstatutes, etc).

Safety rules and precautionsSince all demolition work incurs a certain elementof risk, a large number of regulations apply con-cerning:• the work site itself,• the equipment in use,• work site personnel,• safeguards against uncontrolled collapse,• safeguards against fire, explosion and flooding

etc.

Third party protection• right of access - cordoned-off areas,• local statutes and restrictions

Protection of private propertyVibration disturbance to neighbouring buildings.

Insurance liabilityAll the necessary insurance coverage must be ar-ranged.

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Demolition methods andequipment

Demolition using hand-held toolsDemolition is usually carried out by chipping andtearing down layers horizontally as well as verti-cally. A building is usually demolished in the re-verse order to that in which it was built. Thismethod is usually used for small demolition vol-umes and often as preparatory work for otherdemolition methods. It is highly labour intensive,slow and expensive. Great care must be shown asregards falling rubble.

If the distance to the nearest street or buildingetc. is less than that prescribed, then free fall of thematerial demolished is forbidden and a suitablebuilding hoist, chute or the like must be used.

When sections of a building are demolished, re-maining sections must be checked to ensure thatthey are sufficiently stable. If this is not the casethey must be reinforced or shored. The hand-held

GeneralThe advances in technology within the area ofdemolition have increased the need for more so-phisticated tools and equipment.

The use of such equipment and tools and thelevel of safety for those using them is highly de-pendent on effective cooperation between manu-facturers, contractors and operators. Incorrect useof a tool or equipment is potentially dangerous.Manufacturers cannot be held responsible whenthe tool or equipment is used for a purpose it wasnot designed or intended for.

The contractor is responsible forensuring that:• the tool or equipment is solely used for the type

of work it was designed for,• the tool or equipment is maintained in compli-

ance with the manufacturer’s stipulations andrecommendations

• the operator is properly trained in the use of theparticular tool or equipment,

• the tool or equipment is inspected and tested atregular intervals by qualified personnel.

Demolition methodsA. Demolition using hand-held toolsB. Demolition using rig-mounted breakersC. Demolition using rig-mounted crushersD. Demolition by blastingE. Demolition by splittingF. Demolition by sawing and drilling

Mechanical demolition is the process of creatingtorque or shearing stress through static or dynamicloads on the demolition material.Concrete can withstand high compressive stress

whereas its resistance to tensile stress is low (lessthan 10% of its compressive strength). Concreteshould therefore be demolished by exploiting thischaracteristic. This is not the case when chippingor sawing but it is the case when blasting and split-ting.

Reinforcement bars are embedded in concretestructures where tensile force occurs in order toincrease the strength of the concrete. By subject-ing structures to bending forces through the use ofgrabs, for example, the low resistance to tensilestress can be exploited.

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breakers can either be compressed air, electricallyor hydraulically powered. Different kinds of chis-els are used depending on the material they are tobe used on. The result of the work and the servicelife of chisels depends on such factors as the work-ing pressure, the weight of the breaker, the cuttingedge of the chisel and the bending stress the chiselis subjected to. Chisel edges should be regrindedin good time in order to achieve best results.

The most common type of hand-held equipmentused is usually compressed air powered. The rea-sons for this are their robust design, their reliabil-ity and their easy handling. Also, compressors areto be found at most building sites. For minor jobsor short-term work, electrically powered tools arecommonly used.

Demolition using hand-held tools is expensivebecause of the high labour costs involved. Theproblems that the use of hand-held tools gives riseto in the work environment have also been thefocus of a great deal of attention. These mainlyoccur in the form of musculo-skeletal damage(“white fingers”) and neurological disorders suchas loss of feeling and numbness.

Due to the complexity of the problem there areno prescribed norms and regulations specifyingthe maximum extent to which the method is safeto use. However it is not at all unusual for indi-vidual contractors themselves to draw up their

own rules and regulations to safeguard their em-ployees. As a rule therefore, hand-held tools areonly used when alternative methods have provedthemselves unsuitable, or when there is insuffi-cient space on site for rig-mounted equipment orwhen the coverage area of the latter is inadequate.

Nowadays rig-mounted equipment is availablethat is specially designed, compact and easy tooperate and ideal for use in cramped narrowspaces (See Brokk 40 further on).

Demolition using rig-mountedbreakersThe use of hand-held equipment for demolishinglarge volumes of concrete is simply uneconomic.Hydraulic breakers from 30-600 kg are availablefor mounting on different types of carriers. Whencompared to hand-held alternatives, these unitshave the great advantage of delivering much morepowerful impact and feed forces and they are alsomuch more effective. It is common to make use ofthe carrier’s hydraulic system and it is oftennecessary to carry out a swift change of tools be-tween the breaker and other attachments (e.g.bucket).

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This is facilitated through the use of a quick-hitchand hydraulic quick couplings.

Hydraulic breakers demand the use of carrierswith sufficient stability (weight ratio). The crucialfactor here is that the surface the carrier is beingused on is capable of bearing the load. If themethod is used for sideways demolition of highvertical walls or columns, then great care shouldbe taken to avoid collapse on the carrier or opera-tor.

Demolition using rig-mountedcrushers.The use of rig-mounted crushers for demolitionhas become an extremely interesting alternativewhen requirements stipulate low noise levelswhilst demolition work is being carried out. Thecrushers grip the demolition material and crush itand the only sound to be heard is that of the ma-terial being crushed and of rubble falling. Com-pared with using a rig-mounted breaker thismethod often makes it possible to have muchlonger working shifts per day when conditionsand restrictions limit the length of time a breakercan be used.

Demolition by blastingBlasting is sometimes an extremely effectivedemolition method for which Brokk can be anexcellent complement. By weakening the struc-ture of the building at different points it is possi-ble to blast different sections in a controlled man-ner. This can be achieved by using the Brokkdemolition machine to create a number of “weak-ened points” in accordance with the calculationsof blasting experts. Brokk can also be used after-wards to chip or cut down any sections, parts ofwalls, floors etc. not completely demolished bythe blasting.

IMPORTANT! All blasting requires an extremelyhigh level of professional expertise. A thoroughblasting programme must be drawn up first andapproved by the respective authority (Local Build-ing Committee).The police should also be informed so that theycan cordon off the area in question.

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Demolition by splittingWhen large sections of concrete must be demol-ished or when large openings are to be made, andwhere the use of explosives is impossible, suitablesplitting equipment can be used. This method hasa negligible effect on the surrounding environ-ment, does not create shock waves and generateshardly any dust, noise or flying fragments. The useof splitting equipment requires the predrilling ofholes for insertion of the splitting cylinder orwedge. Even in the case of demolition by splitting,Brokk can be used to advantage in combinationwith other equipment in the preparatory and fin-ishing stages of the work. With the bucket at-tached, Brokk can also be used for removingdemolition materials.

Demolition by sawing and drillingThese methods are used either for total removal ofsections or as a preparatory measure for clearingan area for demolition and often occur in combi-nation with other demolition methods. Sawingproduces accurate cuts and smooth edges and re-quires less secondary work than chipping. Circu-lar saws cut through concrete both vertically andhorizontally to a depth of 40 cm.

An ever increasing number of contractors usingthese methods now use Brokk as a complement sothat they can select the best possible demolitionmethod for each individual object to be demol-ished.

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The previous chapter dealt with the manner inwhich different technical circumstances affect theselection of method. Other important factors arethe costs and the time required for each of thevarious methods. These must be compared in or-der to calculate and submit a tender for a demoli-tion project. Tenders within the demolition busi-ness often vary substantially.

The more highly specified and detailed prelimi-nary enquiries and specifications are, the moreconfidently the contractor can submit a tender. Ofequal importance is a thorough inspection of theobject to be demolished. Factors that often under-lie large variations in tenders are:

• lack of cost assessment experience• inaccurate analogical conclusions• incorrect assessment of the degree of

reinforcement• unforeseen mechanical adjustments• change of method• unforeseen breakdowns• sorting of demolition materials, transport to

environmental station etc

Some rules of thumb concerning costs may be ofinterest here:• demolishing a concrete building is at least

twice as expensive as demolishing an olderbrick building of the same size;

• for reconstruction purposes it is 5-10 timesmore expensive to demolish concrete than tocast it calculated per m3.

Capacities and costs

CostsIn the following cost analysis, the figures quotedshould be regarded as guidelines as they are de-pendent on a number of factors that can vary con-siderably.

The figures referring to demolition relate to thecost per solid m3 and those sawing per m2 of sawnarea. Regarding capacity, the figures quoted referto an average capacity (fm3/h) during an 8 hourshift. This is estimated to be 50-60% of the maxi-mum hourly capacity. The costs specified arebased on the cost level for 1999.

When demolishing reinforced concrete withhand-held tools a capacity of ca 0,1-0,3 fm3/h is at-tained at a cost of 5600-1440 SEK m3. Equivalentcosts using a 250kg rig-mounted breaker are ca800-400 SEK fm3. This clearly shows the eco-nomic advantages of using rig- mounted breakers,space permitting, instead of hand-held ones.

Apart from the lower cost aspects of rig-mounted breakers, substantial time-saving is im-portant too. This decreases total demolition timeand allows other kinds of work to be started ear-lier, thereby achieving capital rationalization.

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Masonry 480-1300 SEK/fm3

Non-reinforced concrete 720-1450 SEK/fm3

Lightly reinforced concrete 1150-2000 SEK/fm3

Heavily reinforced concrete 1600-6400 SEK/fm3

(The figures above refer to machines up to the 10ton class).

The costs distribution for hand-held equipment isas follows:Approx. 75% for labour costsApprox. 15% for wear and serviceApprox. 10% for equipment depreciation

For rig-mounted breakers the corresponding fig-ures are:Approx. 55% for labour costsApprox. 30% for equipment depreciationApprox. 15% for wear and service

Demolition using rig-mountedbreakersThe diagram below shows the capacity and costsfor different size breakers and carriers. The trendis to avoid the use of excessively heavy breakersbecause the costs incurred by the large excavatorsrequired for their use are very high.

The values in the diagram are intended as com-parison between different size breakers and differ-ent types of demolition materials. The valuesshould be regarded as a guideline since they areaffected by a range of different factors such as thethickness of the concrete, its location, etc.

From the diagram we can see that when work isbeing carried out in heavily reinforced concreteusing a 400 kg hammer, a capacity of about 1,5-2,5 fm3/ h can be reached at a demolition cost ofabout 640-400 SEK/fm3. This applies to horizon-tal demolition.

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Breaker 1200 kg

800SEK/fm3

640 500 320

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160

Breaker 250 kg

Breaker 400 kg

Breaker 600 kg

Breaker 900 kg

Breaker 1200 kg

Breaker 900 kg

Breaker 600 kg

Breaker 400 and 250 kg

Heavily reinforced concrete

Non-reinforcedconcrete

Lightly reinforced concrete

Masonry

Demolition volumes and costs decrease in relation to the weight of the breaker used. The diagram above showsthe differences between different qualities of concrete. The harder the material, the heavier the hammer requiredfor efficient demolition.


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Demolition with Brokk usingbreaker or crusher

Capacity

BlastingThe following factors affectcapacity and cost:• the dimensions of the building’s structures,• the type of construction material,• the type of explosives to be used,• the amount of blasting to be carried out etc.

The holes drilled are usually spaced at a distancesimilar to the thickness of the material, and witha hole depth 2/3rds of its thickness. This will re-sult in suitable fragmentation of the material andeliminate the need to subsequently break it up forloading or transportation. Consequently, the lessthick the material the greater the number of drillmetres necessary per solid fm3 material. See dia-gram.

The arcs in the diagram clearly show that withconcrete of a specific thickness, it will be substan-tially cheaper to blast than chip with breakers. Thethicker the concrete the greater the difference. Inthe case of heavily reinforced concrete, the break-ing point lies somewhere between concrete 1 and1.5m thick. For non-reinforced concrete the cor-responding limit is 1.5 metres and upwards. For

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total demolition of high-rise buildings blasting isalways a better alternative from the cost aspectthan the use of other methods, irrespective of thestrength of the material to be demolished. On theother hand, blasting is not always appropriate. Thecost relationship between blasting and chipping isillustrated below.

Cost

Blasting

Thickness of concrete

Chipping

Capacity/hLength of wall

(2200 mm high, 150 mm thick)

Length of wall(2200 mm high, 300 mm thick)

Length of wall(2200 mm high, 500 mm thick)

Brokk 40 0,5 - 1,5 - -

Floor 150 mm/increased capacity

in %

Double reinforced reduced capacity

in %

+ 20 - 50

Foundation 2x2x1 mtime required

With crushersreduced capacity

in %

Brokk 110 1,5 - 2,0 1,0 - 1,5 - + 30 - 30

Brokk 150 2,5 - 3,5 1,5 - 2,5 - + 20 - 20

Brokk 250 4,0 - 6,0 3,0 - 4,0 0,5 - 1,5 + 30 - 15

Brokk 330 8,0 - 11,0 4,0 - 5,0 2,0 + 30 - 5

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20 h

14 h

8 h

4 h

- 10-50

- 10-50

- 10-50

- 10-50

- 10-50

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The table above shows the average capacity figures for demolition of concrete structures using Brokk.

The diagram shows the cost relationship between blastingand chipping. Chipping is the most economicalalternative for concrete structures of thin or normalthickness.


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SawingThe capacity obtained when sawing depends onthe depth of the cut and the feed rate which in turnis dependent on the strength of the material and thepositioning of the reinforcement bars. Capacity isalso affected by:• the manner in which the guide rails and attach-

ment devices are arranged;• resetting of sawing positions• water flushing

Average cutting capacity (m2/h) using diamond-edged saw blades and a sawing depth of up to0.4m in floors are presented in the adjacent dia-gram.

For wall sawing the capacity will be substan-tially lower; only 40-50% of the floor cutting ca-pacity. Costs are greatly influenced by the qualityof the blades, the stability of the unit and the set-up arrangement of the saw. Blade service life andcosts are influenced by the strength of the materialbeing cut, the feed rate, peripheral speed and feed

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1000SEK/fm3

Operating capacity m3/h

800 600

Masonry Lowquality

concrete

Highquality

concrete

Lightlyreinforcedconcrete

Heavilyreinforcedconcrete

400

1,5

1,0

0,5

200

m2/h

Cuttingcapacity

Operatingcapacity(for an 8 hour shift)

Masonry Non-reinforcedconcrete

Reinforcedconcrete

2,0

1,0

0

force applied. The feed rate ≈will lie within the re-gion of 0.5-1.2m/min with a feed force of 2-3 kNand a peripheral speed of 30-60 m/s.

There are different kinds of blades for differentkinds of material.When cutting through standard reinforced con-crete floors, the total cost lies between 960-1150SEK/m2 cut. When sawing walls this figure canincrease up to 2700 SEK/m2 cut.

The diagram above shows the cutting and operatingcapacity for floor sawing.

This diagram will serve as a guide when assessingcapacity and cost for sawing.


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fCore drillingCapacity in this case depends on the qualities ofthe material being core drilled, the rotation speed,feed force and cooling efficiency. The relationshipbetween the rotation speed and the feed forceapplied is particularly important for obtainingminimal wear of the core bit.

A sufficient supply of water must be availablefor the cooling of the core drill and flushing awaydrill cuttings. Core bit diameters of up to 600 mmare used and the peripheral speed of the bit variesbetween 2-5 m/s. A bit with a diameter of 200 mmrequires a feed force of about 10kN and a powersource of about 10 kW. The following operatingcapacities apply:

Core drilling is the method usually used to drill theholes for insertion of splitting cylinders.This therefore is a combination-method for split-ting a series of holes drilled along the contour ofan opening and subsequently splitting between theholes. The openings along the contour will berather uneven so secondary work will be neces-sary.

The method does not impact negatively on theenvironment. Core drills are also used for smallerholes for service lines or cable penetrations.

Heavily reinforced concrete 2,0

Lightly reinforced concrete 3,0

Non-reinforced concrete 4,0

Masonry 4,0

1,0

1,5

2,0

2,0-3,0

Metres drilled/hMaterial

35 mmDiameter of bit 400 mm


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Partial demolition anddemolition forreconstruction.

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During the 1960s there was a substantial boom innew construction. This large volume is now inneed of repair, reconstruction and development.Therefore, demand in this sector is likely to behigh for some time to come. Even the re-use ofbuildings of historical and cultural value demandscareful partial demolition, thereby safeguardingtheir internal and external features and increasingtheir value. Renovations of this type are often veryexpensive and involve environmental problemsfor the work crew, neighbours and surroundings.

As a rule, changes in the concrete structures ofa building have to be carried out by creating open-ings etc. A large number of factors influence thechoice of method for concrete demolition and theone that is best varies from case to case. The mostcommon methods for partial demolition and open-ing up holes are:

• chipping with hand-held equipment• rig-mounted hydraulic breakers• diamond sawing• core drilling• splitting• cautious blasting

The principles for the above-mentioned methodshave already been dealt with. However, in recon-struction work it is particularly important to takeprecautions to minimize disturbance to the sur-roundings, and limit damage to other sections ofthe building. Work in the vicinity of the site mustalso be allowed to continue. Reconstructiondemolition primarily involves the removal ofwalls and the creation of holes. The latter can varysubstantially in size, ranging from large holesdown to holes for service lines or cablepenetrations.

Using the different methodsThe choice of method often depends on the avail-able transport facilities for the equipment and thetransport equipment that is available for removalof the demolished material. When demolishingwith rig-mounted breakers care must be taken toprevent cracks forming in remaining structures.

In many cases the formation of dust on site mayrequire control through water flushing and then itis imperative that the water is removed. Whencreating holes the contour edges will be jaggedand uneven, which in turn necessitates secondarywork.

Traditional rig-mounted breakers require con-siderable space. Brokk demolition machines canwork in confined spaces and can be transportedthrough areas of a building or demolition site thatare cramped. They are also very environmentallyfriendly for the operator to use. Using Brokkmeans that operators are no longer subjected tothe hazards involved in manual demolition.

Mechanisation of this type of work can make itmore economically viable to repair and renovateold buildings rather than to simply demolish themtotally and build new ones. The great risks some-times involved in manual demolition due to un-known factors relating to the building and theconstruction materials, are reduced thanks toBrokk.

Cutting methods (sawing and core drilling) re-quire water cooling and devices for removing usedflushing water. Sawing entails cutting through thereinforcement bars so that the existing reinforce-ment cannot be re-used. Sawing offers low capac-ity but high precision. The risks of damage toexisting structures are minimal and vibration is


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slight. As the sawn surfaces will be even and cutwith precision, the amount of secondary workrequired will be minimal.

Core drilling is used for smaller holes intendedfor cable penetrations etc. and for holes in con-junction with splitting.

The combination of core drilling/splitting isused for opening up larger diameters and whereholes are predrilled along the contours of a struc-ture prior to splitting. This is a relatively quietmethod which does not impact negatively on theimmediate environment. Care must be taken how-ever, to ensure that the powerful forces transmit-ted from the splitting equipment do not damageneighbouring structures.

Splitting involves poor control of the size of theopening and results in rough surface edges, whichin turn necessitates secondary work. When con-sidering controlled blasting for partial demolition,licensed personell must be contacted. (For furtherinformation about this method, please see Chap-ter 4).

Costs and capacities for partialdemolitionGuidelines have already been given relating tocosts and capacities for the different methods pre-sented. For partial demolition these values arefurther affected by other factors such as the

number of holes to be opened, the size of the holes,the thickness of the structure, whether it’s a caseof vertical or horizontal demolition, and last butnot least the space available.

For those methods that require secondary work,this cost also should be taken into account andincluded in the final cost assessment. The cost ofsecondary work varies considerably, dependingon the skill of the operator and whether the workis to be done horizontally or vertically. This costafter sawing is, however, negligible.


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Below is a list of the current Brokk models and thetype of demolition work they are generally usedfor.

Method and machine selection can vary fromcase to case depending on machine availability, op-erator skills and the requirements/regulations thatapply to each individual demolition assignment.Please make a special note of the following points:• the thickness of the material• the hardness of the material (e.g. special reinforced concrete)• the total volume of the demolition• the bearing capacity of the surface (floor struc-

ture etc.)

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Model Characteristics General Materials Special areas of use

Brokk 40 Small and handy.Can pass throughnarrow openings easily. Ideal for sensitive surfaces

For small scale work indoors instead of using hand-held equipment. Ideal for use in confined spaces.

Concrete, tiles, clinker Flats, bathrooms, thin walls and floors, (max.200mm), balconies (from scaffolding), changing pipes, roof and chimney work, demolition of stairs, minor digging, in connection with sensitive bridge work, variety of service work

Brokk 110 Compact machine, light in relation to its capacity

For general demolition work

Concrete, brickwork For general demolition on normal floor structures, pile driving, demolition of piping, lightwells, staircases, cement roofs

Brokk 150 Compact machine with a slightly higher capacity than the Brokk 110.

For general demolition work that is somewhat heavier.

Concrete, brickwork For complete demolition or heavier demolition work, brick lining in ovens, demolition atindustrial buildings, bridges and multi-storey car parks

Brokk 330 Compact machine with extra reach and power for the heaviest of demolition assignments

Heavy demolition Concrete etc. Heavy structures, heavily reinforced objects (e.g. bank vaults), demolition of balconies demolition of beams, scaling, demolition of shafts

Brokk 250 Compact machine with reach and capacity

Heavier demolition work

Concrete etc. Foundations, beams, pillars, walls, floor structures up to 500mm thick, demolition of cellars, digging, renovating tunnels, where the actual work may require the capacity of a Brokk 330 but the floor is too sensitive for it(e.g. marble floors)

Demolition with Brokk• the possibility of transporting the machine at the

demolition site (capacity of lifts etc).• requirements regarding removal, environmental

source-sorting and recycling of materials


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over a larger area. That is why it is possible totransport Brokk machines across sensitive sur-faces without any risk of damage to the surfacesthemselves.

During demolition, when the supporting legshave been opened out, weight distributing diskscan be used if necessary.

ReachIts trisected arm has an extremely long reach(please see model descriptions for exact dimen-sions). See adjacent diagram.

Remote controlRemote control of Brokk machines via cable/radiois one of the advantages that are the main featuresof the Brokk concept. Remote control of the ma-chines impacts extremely positively on the workenvironment (please see section on environment).Conversely, it is possible for the operator to standvery close and have an excellent view of any workrequiring great precision.

Creative demolitionNo matter how strange it may sound, the demo-lition business is actually extremely creative. Byinvesting in Brokk demolition machines each in-dividual contractor gains great freedom of choiceas regards demolition methods and innovativesolutions for increasing efficiency and profitabil-ity. The machines can also be used with each otherand with other demolition methods in a variety ofcombinations.

One example comes from balcony demolition.For work of this nature, a Brokk 40 that has beenlifted by crane or is on a scaffolding can be ex-tremely effective. Another alternative is to allowa Brokk 330, fitted with crusher, exploit the entirelength of its reach to demolish balconies from itssecure position on the ground below.

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Brokk 330

(m) Reach - Brokk 330 vs Brokk 40

Brokk 40

Compact capacityExternal dimensionsAs has been previously stated, Brokk is a demo-lition machine with great capacity. Its capacityshould be seen in direct relation to the smallnessof its dimensions and the lightness of its weight.The advantage of its smallness becomes particu-larly apparent when the demolition area iscramped and confined.

For example, the Brokk 40 can pass throughopenings as narrow as 60 cm. Its low height canbe useful when demolition areas are restricted ver-tically.

WeightIn relation to their demolition capacity, Brokkmachines are light weight. That is why it is pos-sible to use the smaller models on normal floorstructures without the need for any special meas-ures.

When transported at the demolition site theirweight is distributed on rubber caterpillar tracks(this does not apply to machines fitted with steelcaterpillar tracks) which distribute the pressure

The diagram shows the reach of Brokk 40, the smallestmodel compared with Brokk 330, the largest.


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Transport/accessibilityBetween work sitesDue to its light weight Brokk can be transportedbetween work sites easily. A Brokk 40 can betransported in a normal trailer. The larger modelsare transported either on trailer, by lorry or usinga hired vehicle (e.g. a carrier) . The machines areloaded onto these by means of ramps and are sim-ply driven on. Other alternatives are to lift themachines using a truck or something similar.

At the work siteUsually Brokk machines are transported withinthe work site ”under their own steam”. Pleaseensure that the electricity supply has sufficientamperage (depending on the model) and that theelectric cables are long enough.

StaircasesBrokk 40, the smallest model, can be moved innormal staircases. Depending on the staircasedesign (length, steepness and material) blocks canbe laid out and the larger Brokk models can bemanoevered up or down them.

LiftsBrokk 40 can be transported in an ordinary lift(provided that the prescribed weight restrictionsare complied with). Larger models require a hoistwith sufficient capacity.

Cranes

Cranes can naturally be used to lift machines at theactual work site itself. Certain demolition taskscan be performed by simply lifting the Brokk witha crane and carrying out the work with it sus-pended.

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Costs for demolition withBrokkThe following table provides a rough indication ofthe cost ratio incurred when using Brokk fordemolition. The cost is linked to the respectivemodel and the capacity of each machine.

attachments increases the range of application forBrokk and creates more opportunities for profit-able working methods. In the case of large scaledemolition work for which a particular attachmentis ideal, the investment involved can sometimespay for itself after just one single assignment.

The design makes it possible to quickly changebetween different attachments. Below is a descrip-tion of the various attachments that can be used.This area is developing very rapidly indeed andnew tools are being developed all the time.

BreakersHydraulic breakers from all leading suppliers canbe attached to Brokk.

CrushersCrushers have become an exciting alternative tochipping breakers especially in places where ”si-lent demolition” is required e.g. built-up areas orreconstruction-demolitions where regular dailyactivities are in progress at the same time as the

Brokk 40

Brokk110

Brokk 150

Brokk 250

Brokk 330

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The hourly cost for Brokk 330 is ca 70 percentabove the hourly cost for Brokk 40. If the hourlycost for Brokk 40 (including operator) is 500 SEKthen the cost for Brokk 330 is 850 SEK.

As far as tenders are concerned, estimating thescope of an assignment and the number of work-ing hours required plays a vital role in deciding atotal price.

Operator expertiseThe operator’s experience and expertise is abso-lutely crucial as regards capacity and efficiency.An experienced skilful operator can demolishtwice as much as one that is inexperienced. Know-how and previous experience gained from similardemolition projects are needed to handle thesemachines. Brokk AB and various associates offercontinuous operator training.

ToolsBrokk is usually fitted with a chipping breakerwhich makes it an effective and all-round demo-lition machine.

Today there are several other ways of utilizingthe total capacity of the Brokk machine. Use of the

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demolition. There are several examples of this e.g.the reconstruction of department stores and indoorshopping malls where, as far as noise is con-cerned, crushers make it possible to carry outdemolition work for longer periods per day.

Capacity-wise the use of crushers results in asomewhat reduced volume of demolition (com-pared with chipping breakers). However, if cir-

The larger themodel, the higherthe cost per hourworked.


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cumstances are as described above, their use re-sults in a higher daily volume of demolition.

Crushers crush the demolition material bymeans of hydraulic pressure. What is of crucialimportance as regards the use of crushers is thehardness of the material, the speed of the crushersand the thickness of the material (which must notexceed the cutting width of the crushers). Rein-forcement bars can be cut using a special pinch-function integrated in the crushers (does not applyto Brokk CC260).

GrapplesGrapples are used in special circumstances whereit is necessary to grab hold of materials such as ca-ble racks , ventilation drums, pipes etc. to tear, pullor lift them.

BucketsBrokk can be fitted with a bucket to enhance flex-ibility and extend its range of use. This is idealwhen the space where the demolition is to be car-ried out is confined. Brokk also facilitates the re-moval of materials because, thanks to its compactsize, it can be used for this purpose too.

There are also times when Brokk is used solelyfor digging, e. g. when restrictions require onlyelectrically powered machines.

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ScabblersScabblers are used when a surface layer needs re-moving e.g. in renovation work when the body orframe of the object is intact but the area of wearis damaged. There are different scabbler modelsfor different kinds of use, depending on the mate-rial that is to be removed.

Brokk and theenvironmentThe environmental aspects of demolition work arecoming under the spotlight to an ever increasingdegree. Brokk AB work continuously on theseissues in a serious manner. This applies not onlyto the production at Brokk AB but also to how thewhole concept of demolition machines impacts onthe environment at the general and individuallevel.

Work environment, operatorThe general ergonomic work situation of the indi-vidual operator has become the focus of interest.When hand-held tools are used there is a great riskof repetitive strain injuries occurring due to thevibration e.g. so-called ”white fingers”. The op-erator is also exposed to a range of dangers whencarrying out demolition work at the site: suddencollapses, falling rubble etc. To these can be addedthe risks of dust and exhaust fumes.

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Using the remote-controlled electrically poweredBrokk eliminates these risks or reduces them sig-nificantly. This means that the drawbacks of work-ing with hand-held tools do not apply to Brokk.

Work environment, generalIt is in this area that special attention can be fo-cused on the fact that Brokk is electrically pow-ered. This means the elimination of exhaust fumes- a demand that is being made by an increasingnumber of clients both in industry and in thedemolition business. A further advantage is thatBrokk produces a very low level of noise.

Sorting at source, recyclingSorting at source for the purpose of recyclingbuilding materials is to an ever increasing degreebecoming part of the demolition contractor’s as-signment. Experience gained from carrying outdemolitions with Brokk has been very positiveindeed in this respect. In particular as regardswork where concrete crushers are used, since thematerial can be separated and cut into suitablysized lumps for quick efficient sorting.

Concrete crushers can also be used for pullingwindow and door frames loose so as to separatematerial of this kind from e.g. concrete.

Brokk ABP.O. Box 730SE-931 27 Skellefteå, SwedenTel +46 910 711 800Fax +46 910 711 811E-mail: [email protected], www.brokk.com

For further information,please call us at

+46 910 711 800

)

Demolition handbook EN - Inicio - · PDF filemethod is usually used for small demolition...

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