Deliverable 7.5 Guidelines for site organization and...

DEVELOPING INNOVATIVE SYSTEMS FOR REINFORCED MASONRY WALLS

COOP-CT-2005 CONTRACT N. 018120

Construction and testing of prototypes D7.5 of 46

Deliverable 7.5

Guidelines for site organization and execution for end-users

Due date: January 2008 Submission date: January 2008

Issued by: CISEDIL

WORKPACKAGE 7: Construction and testing of prototypes (Leader: CISEDIL)

PROJECT N°: COOP-CT-2005-018120

ACRONYM: DISWall

TYTLE: Developing Innovative Systems for Reinforced Masonry Walls

COORDINATOR: Università di Padova (Italy)

START DATE: 16 January 2006 DURATION: 24 months

INSTRUMENT: Co-operative Research Project

THEMATIC PRIORITY: Horizontal Research activities involving SMEs

Tourist village in Puegnano del Garda

Sport centre in Reggio Emilia

Dissemination level: PU Rev: FINAL




INDEX

INDEX................................................................................................................................................................ 3 1. INTRODUCTION ....................................................................................................................................... 5

1.1 DESCRIPTION AND OBJECTIVES OF THE WORK PACKAGE.................................................... 5 1.2 OBJECTIVES AND STRUCTURE OF THE DELIVERABLE........................................................... 5

2. PROJECT PLANNING............................................................................................................................... 6 3. MATERIALS............................................................................................................................................... 7

3.1 GENERAL ........................................................................................................................................ 7 3.2 UNIT ................................................................................................................................................. 7

3.2.1 Perforated and Hollow Clay Unit.................................................................................................. 7 3.2.2 Concrete Unit ............................................................................................................................... 8

3.3 MORTAR.......................................................................................................................................... 8 3.3.1 General purpose mortar for perforated clay and concrete unit masonry..................................... 8

3.4 GROUT ............................................................................................................................................ 9 3.4.1 Grout for hollow clay unit masonry .............................................................................................. 9

3.5 REINFORCEMENT AND ACCESSORIES ...................................................................................... 9 4. SITE ORGANIZATION............................................................................................................................. 12

4.1 DELIVERY, STORAGE AND HANDLING OF MATERIALS.......................................................... 12 4.2 PREPARATION OF WORKS, MATERIALS AND COMPONENTS............................................... 13

5. EXECUTION OF REINFORCED MASONRY WALLS............................................................................. 15 5.1 MASONRY ERECTION.................................................................................................................. 15 5.2 REINFORCEMENT, TIE, AND ANCHOR INSTALLATION ........................................................... 16 5.3 GROUT PLACEMENT ................................................................................................................... 19 5.4 TEMPORARY BRACING ............................................................................................................... 19 5.5 TOLERANCES............................................................................................................................... 20 5.6 PROJECT CONDITIONS............................................................................................................... 21

5.6.1 Cold weather construction ......................................................................................................... 21 5.6.2 Hot weather construction ........................................................................................................... 22

6. QUALITY ASSURANCE MEASURES AND POST-CONSTRUCTION................................................... 24 6.1 INSPECTIONS............................................................................................................................... 24 6.2 TESTING........................................................................................................................................ 25 6.3 POST CONSTRUCTION AND MAINTENANCE ........................................................................... 26

7. DETAILING .............................................................................................................................................. 28 7.1 REINFORCED MASONRY WITH PERFORATED CLAY UNITS.................................................. 28

7.1.1 Reinforced masonry made with vertically perforated clay units................................................. 28 7.1.2 Reinforced masonry made with horizontally perforated clay units ............................................ 30




7.2 REINFORCED MASONRY WITH LARGE HOLLOW CLAY UNITS.............................................. 32 7.3 REINFORCED MASONRY WITH LARGE HOLLOW CONCRETE UNITS................................... 34

8. EXAMPLES.............................................................................................................................................. 36 8.1 REINFORCED MASONRY BUILDINGS WITH PERFORATED CLAY UNITS ............................. 36

8.1.1 Residential buildings .................................................................................................................. 36 8.1.2 Service, commercial and industrial buildings............................................................................. 38

8.2 REINFORCED MASONRY BUILDINGS WITH HOLLOW CONCRETE UNITS............................ 39 REFERENCES ................................................................................................................................................ 41 ANNEX: NETWORK OF EXPERTISE ON REINFORCED MASONRY.......................................................... 44




1. INTRODUCTION

1.1 DESCRIPTION AND OBJECTIVES OF THE WORK PACKAGE

The major aim of DISWall project is the proposal of innovative systems for reinforced masonry walls. The

validation of the feasibility of the systems as a whole, to be used as an industrialized solution, involves the

study of the technical, economical and mechanical performance. The outcomes of WP3, WP4, WP5 and

WP6 represent the answer to the main project goal. The workpackage 7 is the final demonstration about the

feasibility of the envisaged solutions in real site conditions. The construction of one or more than one case

study, where adopting the newly defined construction technologies, allows incorporating the constructor’s

viewpoint in the definition of the technology. It also allows assessing the specific problems connected with

this kind of structure, which are of a high degree of complexity, since they involve a real site, with a real

client having real needs. The non-destructive testing of the real case execution is of critical importance to

validate the workmanship and adequacy of the proposed solution and evaluate the on-site applicability of

NDT (D7.4). Output obtained from construction and testing can be used to make a proper assessment of the

construction technology itself, taking into account technical, security and economical aspects, which all

merge into the guidelines for end-users (D7.5).

1.2 OBJECTIVES AND STRUCTURE OF THE DELIVERABLE

These guidelines give general recommendations for the site organization, the execution and workmanship of

reinforced masonry structures. They cover the main aspects related to the construction of perforated clay

units, hollow clay units and concrete units reinforced masonry buildings, other than structural design, which

is covered by D6.2. They include advices on a range of practical issues and figures and drawings showing

masonry details. They are not intended to cover any other type of reinforced masonry besides those above

mentioned. The recommendations in these guidelines are based on literature research and on the

experience gained through construction and testing of masonry wall specimens and real walls in the

framework of the DISWall project. They are intended for everyone involved with reinforced masonry: clients,

designers, specifiers, constructors (house builders, specialist and general contractors, SME’s and Self

Builders) and Building Controllers, and is end-users focused.

The guidelines are structured into eight main sections. After the introduction, there is a short reference to the

project planning phase. Following, the materials specifications and the site organization are described. The

construction phase is subsequently described. Mention is made to the quality assurance procedures and to

the phase of post-construction. After that, there is a series of common constructive details for the different

reinforced masonry systems and a series of real reinforced masonry buildings examples. Finally, some

reference, publications, and relevant standards are listed. In the annex, a network of expertise on reinforced

masonry is created. This section lists a series of main associations, consortiums, etc., involved in masonry

matters and in reinforced masonry in particular. It serves as contact list, from which the end-users can find

the main contacts in their own country.




2. PROJECT PLANNING

The project client should involve the unit manufacturer and the reinforced masonry system dealer (if different

from the unit producer) in feasibility discussions, to enable the unit/system producer/dealer to use their

product knowledge to add value at the conceptual stage. The client’s aims, objectives, needs and

expectations should be made clear. It should be also clear from the beginning that the design phase will

involve more skills, as it will cover structural, thermal, acoustic, fire, durability and other aspects that have to

interact mutually.

Different levels of risk pertain at each phase of the construction process i.e. the earlier a risk is eliminated

the better. Risks should not be transferred down the supply chain e.g. design and other risks should not be

transferred to the construction phase but be resolved before work starts on site. The process should be

examined systematically to estimate the risks associated with each phase. Allowances should then be made

for these. The project planners should provide the unit/system producer/dealer with the following information

at an early stage in the planning process:

• Location and type of project

• Size of project

• Project programme

• Project partners

• Site information e.g. storage facilities, logistics, etc.

The unit/system producer/dealer should be consulted for advice on the best practice reinforced masonry

solutions to enable correct specifications to be drawn up. When the project objectives are made clear, the

unit/system producer/dealer should advise on all aspects of the supply chain, conceptual design and relevant

methods of construction. The early involvement of the manufacturer with their advice on best practice

solutions leads to lowering costs by working efficiently rather than by merely going for lowest cost first.

The quality of the construction will be ensured not only by good quality of the materials, but also by high level

workmanship, proper detailing, and by morphological and constructive regularity, which will guarantee the

adequate performance of the building under serviceability condition and under extreme actions.

From the beginning and throughout the project, feedback and communication between all participants should

be continuous to obtain maximum client satisfaction. The integrated team produces better contractual

relationships and oils the mechanism for a smoother delivery of the completed project. The project will as

such meets with the expected quality standards. Also the involvement of the manufacturer/dealer should not

end after the project planning stage and the sale of the system, but should continue during the construction

stage. In particular at the beginning of the construction, the producer/dealer technical consultant should carry

out site inspection to instruct the project contractors and check the workmanship. The unit/system

manufacturer/dealer are available, through their technical consultants, to give advice on the suitability and

availability of alternative reinforced masonry solutions when required by telephone, email, letter, and fax or in

the enquirer’s office, throughout the entire duration of the construction [Aircrete Product Association, 2002].




3. MATERIALS

3.1 GENERAL

This section sets out the requirements for materials for reinforced masonry construction. In general, the units

should comply with the EN 771 series, the masonry mortars should comply with the EN 998-2, whereas the

rendering and plastering mortars should comply with the EN 998-1. The concrete properties should comply

with the EN 206-1, the ordinary steel for the reinforcement of masonry should comply with the EN 10080 and

the prefabricated truss steel reinforcement should comply with the EN 845-3 and EN 846-3. Further

requirements are set out into the national and European codes. Furthermore, a complete list of requirements

for the materials, together with the respective testing standards or regulations, are given in the report about

the requirements for masonry units, reinforcement, mortar and concrete (D3.1).

3.2 UNIT

3.2.1 Perforated and Hollow Clay Unit

Perforated and hollow clay masonry units should comply with the EN 771-1 as concern the general

requirements. If special clay units for the construction of flues are used, they should comply with the EN

1086. The appearance of the clay unit is a matter of agreement between the specifier or user and the

manufacturer or supplier. In general, the units need to be reasonably free from deep or extensive cracks and

from damage to edges and corners, from pebbles and from expansive particles of lime. In fact, also in a high

quality production, some elements could presents defects not only due to the manufacturing phase, but also

to the transportation. During the block laying, the units that present defects such as cracks, in particular on

the external shells and for the construction of pillars, corners, masonry piers between windows and doors,

should be discarded [Zanarini, 1999].

The perforated clay units to be used for load bearing masonry generally should be of Group 1 or 2 according

to Table 3.1 in EN 1996-1-1 (2005). The percentage of holes, in these cases, is lower than 55%. If elements

of Group 4 are used (with horizontal holes), the percentage of holes should be anyway reduced with respect

to the maximum percentage allowed for this group of units (70%). The other geometrical requirements

regarding the thickness of webs and shells and the maximum dimensions of the holes can be found in the

EN 1996-1-1 (2005). According to EN 1998-1 (2004), in seismic area the units should have sufficient

robustness in order to avoid local brittle failure. They should have normalised compressive strength normal

to the bed face and parallel to the bed face in the plane of the wall not less than, respectively, 5 N/mm2 and 2

N/mm2. However, some national standards could call for tighter geometrical and mechanical requirements.

For example, the OPCM 3431 (2005) and the DM 14/09/2005 (2007) in Italy require for load bearing

masonry in seismic areas maximum percentage of holes equal to 45%, the requirement about the unit

robustness is converted into the fact that the webs parallel to the plane of the wall should be continuous and

rectilinear (apart for the presence of possible gripholes), the characteristic compressive strength normal to




the bed face and parallel to the bed face of the unit in the plane of the wall should not be less than,

respectively, 5 N/mm2 and 1,5 N/mm2.

3.2.2 Concrete Unit

Concrete masonry units should comply with the EN 771-3 concern the general requirements. In general, the

units need to be reasonably free from deep or extensive cracks and from damage to edges and corners,

from pebbles. In fact, also in a high quality production, some elements could present defects not only due to

the manufacturing phase, but also due to the transportation. During the block haying, the units that present

defects such as cracks should be discarded.

The concrete units to be used for load bearing masonry generally should be of Group 1 or 2 according to

Table 3.1 in EN 1996-1-1 (2005). The percentage of holes, in these cases, is lower than 60%. If elements of

Group 3 and 4 are used, the percentage of holes should be anyway reduced with respect to the maximum

percentage allowed for this group of units (70%). The other geometrical requirements regarding the

thickness of webs and shells and the maximum dimensions of the holes can be found in the EN 1996-1-1

(2005). According to EN 1998-1 (2004), in seismic area the units should have sufficient robustness in order

to avoid local brittle failure. They should have normalised compressive strength normal to the bed face and

parallel to the bed face in the plane of the wall not less than, respectively, 5 N/mm2 and 2 N/mm2.

3.3 MORTAR

3.3.1 General purpose mortar for perforated clay and concrete unit masonry

General purpose masonry mortars for perforated clay unit reinforced masonry walls should comply with the

EN 998-2. Pre-mixed and ready-to-use mortars provide consistent properties and can be used with

advantage, particularly on large projects. Where mortars are mixed on site the specified proportions should

be adhered to. The cement and lime suitable for use in mortars should comply to EN 197-1 and EN 459-1.

Sand should be well graded and comply with EN 13139. Additives for masonry mortar should comply with

EN 934. The mixing water should be clean. The mortar should be specified as either “designed” or

“prescribed”. A designed mortar is referred to by the compressive strength class of the hardened mortar

(e.g., M4 that means average compressive strength equal to or higher than 4 N/mm2). A prescribed mortar is

referred to by its constituents and their specific proportions in the mix (e.g. cement:lime:sand 1:1:6).

When mortar is gauged by volume use a gauge box, bucket or similar standard container for each material.

Use containers of a size to be completely filled to proportion each batch. When cement is supplied in bags it

is preferable to use whole bags of cement for any mix. Do not use additives except where specified by the

designer. To prepare the mortar, mix cementicious materials and aggregates in a mechanical batch mixer

with a sufficient amount of water to produce a workable consistency. Do not load a mixer to more than its

rated capacity. If pre-mixed mortar is used, use preferably the water ratio suggested by the manufacturer.

Unless acceptable, do not hand mix mortar. When doing so, use a clean watertight platform. When mixing by




machine, continue mixing long enough to obtain a uniform consistency and colour from the ingredients. In

general, a machine mixing time of 3 to 5 minutes, after all the constituents have been added, should be

sufficient. Wide variation in the mixing time of different batches should be avoided [Beall, 2004].

Mortars should be ready for use when they are discharged from the mixer, and no subsequent additions of

binders, aggregates, admixtures, or water should be made. Workability of site-made mortar could be

maintained by retempering by a small amount of water. Avoid excessive water addition, which decrease

significantly the mortar mechanical properties. Do not retemper mortar after initial set and discard mortar

which has begun to stiffen or is not used within about 2 hours after initial mixing (for cement based mortars).

This time may be shortened in hot weather (see also section 5.6.2).

According to the EN 1996-1-1, the reinforced masonry should be laid in mortar M4 or stronger, and the bed

joint reinforced masonry should be laid in mortar M2 or stronger. For reinforced masonry that is designed to

withstand seismic actions, the EN 1998-1 recommends the use of mortar M10 or stronger.

3.4 GROUT

3.4.1 Grout for hollow clay unit masonry

The Self-Compacting Concrete should feature a compressive strength according to the compressive strength

class C20/25 of EN 206-1. To ensure the self compacting properties and filling ability without additional

vibration the SCC should feature a slump flow between 700 and 750 mm. A further main factor for the

workability of the Self-Compacting Concrete is its viscosity. If the mixture’s viscosity is too high the concrete

will not de-air completely. If it is too low the coarse aggregate tends to a sedimention. The viscosity is

determined using an indirect methods with the concrete-V-funnel. The V-funnel-time should be amount to 10

to 15 seconds. The water retention of the Self-Compacting Concrete should be improved using a special

viscosity modifying admixture.

3.5 REINFORCEMENT AND ACCESSORIES

Ordinary steel for the reinforcement of masonry should comply with the EN 10080 and the prefabricated

truss type steel reinforcement should comply with the EN 845-3. The metal accessories for masonry should

comply with the EN 845-1 and the lintels with the specifications given in EN 845-2.

Reinforcing steel shall be sufficiently durable, either by being corrosion resistant or adequately protected.

According to the EN 1996-2, the possible exposure classes are defined as following: MX1 - dry environment;

MX2 - exposed to moisture or wetting; MX3 - exposed to moisture or wetting plus freeze/thaw cycling; MX4 -

exposed to saturated salt air or seawater; MX5 - aggressive chemical environment. The type of reinforcing

steel, and the minimum level of protection for the reinforcing steel, should be chosen with regard to the

relevant exposure class of the place of use as described in Tab. 1, where the minimum mortar cover for bed

joint reinforcement is given by Fig. 1, whereas the minimum concrete cover for unprotected carbon




reinforcing steel is given by Tab. 2. Where galvanising is used to provide protection, the reinforcing steel

should be galvanised after it has been bent to shape.

Tab. 1: Selection of reinforcement for durability (after EN 1996-1-1)

Fig. 1: Cover to reinforcement in bed joints made of general purpose and lightweight mortars (after EN 1996-1-1)




Tab. 2: Recommended values for the minimum concrete cover cnom for carbon reinforced steel (after EN 1996-1-1)

Some national codes could call for further reinforcing steel requirements. For example, the OPCM 3431

(2005) and the DM 14/09/2005 (2007) in Italy require for load bearing reinforced masonry in seismic areas

the use of ribbed (improved bond) reinforcing steel, when bars are used. Maximum recommended values of

diameter for the steel bars in reinforced masonry are given in the following section 5.2.




4. SITE ORGANIZATION

4.1 DELIVERY, STORAGE AND HANDLING OF MATERIALS

The system manufacturer/dealer should be selected in good time and provided with full information and

accurate specification on the materials and the system, whether the materials forming the system are

required on pallets, required delivery dates and quantities in square metres of walling or weight. When taking

deliveries direct from the manufacturer, the materials should be ordered in full loads to achieve maximum

economy. Particular care should be taken when unit, mortars or reinforcement of different specifications are

being used on the same site. Each different specification should be identified, stored and used in ways which

prevent the misplacing in the works. The materials forming the system should be unloaded using forklift

trucks or the self unloading crane on the delivery vehicle on to a dry stable level surface where they can be

stored until required [Aircrete Product Association, 2002].

It is necessary to arrange, inside the construction site, a storage area, placed so that further temporary

shifting of the materials before their use is not necessary and it does not disturb the works. Packs of units

and other heavy materials should be stacked so they remain stable and safe at all times. For that aim, the

storage area should be flat. All the packaged materials should be stored off the ground and covered to

prevent staining from contact with the soil, moisture, soluble salt and other contaminant penetration, which

may result in efflorescence, defects and lack of bond in the finished work, excessive steel corrosion. It is a

good practice to protect, particularly during the winter season, all the packages from rain, snow, ice, and

blowing dust and debris. In particular the bags of cement, hydrated lime, prepacked mortar mixes, etc., for

later used, should be stored in a dry, frost-free, enclosed shed or building, with different materials in separate

stacks, with bags stacked away from walls. The reinforcement, ties and metal accessories should be

protected from permanent distortions and should be placed in a way that they are not permanently bent.

They should be also stored off the ground and protected from contaminant (oil, dirt, ice) that could prevent

good bond with mortar or grout [Beall, 2004].

The materials should be stored in an arrangement so that consignments can be used in the order of delivery.

The shifting of the materials from the place of storage to the place of their installation should be carried out

using forklift trucks or cranes and should be carried out with particular care in order to avoid damage or loss

of material and to ensure the safety of the men at work. During the construction work, in particular the

handling of heavy building blocks can result in a wide range of injuries. The risk of injury is largely

determined by the weight of the block – the heavier the block, the higher the risk of injury. There is a high

risk of injury from single handed repetitive manual handling of blocks heavier than 20kg. Most units for

reinforced masonry construction are less than 20kg. The manufacturer should give advice about safe

techniques for lifting and laying heavier units, and should provide the contractors with on-purpose hand holds

(Fig. 2), suitable also for lighter units [Aircrete Product Association, 2002].

To eliminate any risk of an incorrect product being placed in the works, everyone involved should become

familiar with the particular product identification details provided by the unit, mortar and concrete and

reinforcement manufacturer, to enable suitable site identification procedures to be adopted.




Fig. 2: Model of hand holds for units

4.2 PREPARATION OF WORKS, MATERIALS AND COMPONENTS

The site should be kept clean and tidy in order to ensure that checking, handling and storage of materials

and components can be carried out speedily and effectively and that the construction operations can

proceed safely. When the materials and components are distributed to the work position, neither the

structure nor the access scaffolding should be overloaded. Furthermore, the materials and components

should be protected to prevent damage or deterioration before use [BS 5628-3, 2005].

The general layout of the building should be checked before casting the foundations. When the vertical

reinforcement restarts from foundations (Fig. 3), its exact positioning should be checked before casting the

concrete and positioners should be placed in order to hold the reinforcing bars in the correct place and in

vertical alignment. Before starting the construction of masonry, it should be checked that the foundations are

built with tolerances that complies with the design specification and that the reinforcement is positioned in

accordance to the project drawings. Furthermore, loose aggregates and anything else that would prevent

mortar from bonding to the foundation should be removed.

Masonry should be set out relative to securely marked or pegged reference lines and datum levels using

appropriate serviceable equipment (Fig. 13). Squareness should be checked with diagonal measurements or

a builder’s square. The datum and profile marks should be securely fixed. The datum level points should be

left in position so that a gauge rod can be used for coursing other heights such as openings, storeys and

string courses. The position of openings, etc., should be anticipated in the starting course prior to carrying

out work in order to avoid unnecessary cutting and adjustment of masonry units at a later stage, which can

lead to uneven bonding, or the incorrect positioning of reinforcement [BS 5628-3, 2005]. The masonry should

be built as described in the following section 5, with the permissible deviations and tolerances as referred to

in section 5.5. If the reinforcement is placed after the construction of the slabs, by means of fasteners or by

fixing it into drilled holes, the first course of units should be dry-laid to individuate the exact positions of the

unit holes in order to precisely fix the position of the reinforcement (Fig. 4) [AA.VV., 1999].




Fig. 3: Reinforcement restarting from

foundations Fig. 4: Dry-laying of the first course for the positioning of the vertical reinforcement

Clay units should be moistened before laying, in order to avoid excessive suction of water from the mortar,

however excessive wetting should be avoided, as the presence of a film water on the clay unit surface hinder

the creation of a good bond with the mortar joint. Conversely, concrete units should never be moistened

before or during placement because they will shrink as they dry out, and this could even cause cracking

[Beall, 2004]. The reinforcement, ties and metal accessories should be cleaned from eventual contaminant

(oil, dirt, ice) that could prevent good bond with mortar or grout. They should be also bent to the design

configuration and linked at the overlapping or at the edges of stirrups, etc., by means of binding wire, before

placing the mortar or grouting. The mortar and grout should be prepared as described in the previous

sections 3.3 and 3.4. The positioning of the reinforcement and the grouting operations are described in the

following sections 5.2 and 5.3. Fig. 5 and Fig. 6 show the general views of two construction sites where

perforated clay units reinforced masonry has been employed as structural system.

Fig. 5: General view of a construction site. Fig. 6: General view of a construction site.




5. EXECUTION OF REINFORCED MASONRY WALLS

5.1 MASONRY ERECTION

Build walls in stretchers unless otherwise specified. A regular bond pattern should be maintained and the

minimum bonding overlap should be a half block length for perforated clay units. In case of concrete

masonry units, reinforced continuous vertical joints are also foreseen. From experimental results this

masonry bond appears to be effective and no significant differences should be found in pratice concerning

the mechanical behaviour. Overhand laying should not be generally used, not even in correspondence of

vertically reinforced cavities. The units may be cut to aid bonding at openings and to provide neat slopes at

the top of gable walls. However, special size coursing blocks are generally provided and should be used to

close cavities at reveals, around the vertical reinforcement and at the tops of walls. Clay unit masonry should

be protected from adverse weather during and for a period after laying; excessive drying out and excessive

wetting; frost during and after laying until the mortar has gained strength [Tubi, 1980]. The same is also valid

to concrete masonry units. Special care should be taken for construction in severe environmental conditions,

as reported in § 5.6.

Units to be laid in general purpose mortar should be laid on a full bed of mortar and the perpend joints

substantially filled, unless the design states otherwise. In certain cases, it could be considered to use shell

bedded joints. In these cases, the proper bedding of the reinforcement into the mortar should be verified.

The use of reinforced masonry with unfilled head joints is not recommended [Zanarini, 2000]. When laying

thin-joint masonry, it is most important that the first course is laid strictly to line, level and perpendicular. The

necessary accuracy of the first course should be achieved by laying the units on a bed of general purpose

mortar to eliminate any inaccuracies from below. The general purpose mortar bed joint should be allowed to

harden sufficiently before the remainder of the wall is built. Thin-layer mortar joints should be formed

between 0.5 mm and 3 mm thick using the proper tools available from the manufacturer. When being laid on

to thin bed joints, any adjustment of the unit position should be completed in few minutes.

The bearings of support beams, lintels and joist hangers when used, should be detailed to avoid transferring

concentrated loads on or immediately adjacent to head joints. The minimum length of lintel bearing should

be in accordance with the design and be installed level and on a full bed of mortar. Avoid the use of off-cuts

of units as they can permit local movements, but use full masonry units immediately below lintel ends [Beall,

2004]. Deep chases and recesses for chimney flues or for the installation of other systems, conduits and

pipes should not be made after the masonry erection, as they constitute discontinuities into the load bearing

masonry. They should be foreseen in the design phase and built and detailed properly, by placing proper

reinforcement at each side of the discontinuity and, eventually, across it [Zanarini, 2000].

Provision should be made, where necessary, for the normal movements which occur in masonry from

shrinkage of concrete products and expansion of clay products. Thermal expansion and contraction

movements may also occur. Attempts to calculate the expected movements have to be considered with

particular care, as the calculations are very complex and, generally, unreliable. In unreinforced masonry,

vertical movement joints can be incorporated in the walls to minimise cracking. The alternative solution is to




reinforce walls with bed joint reinforcement, and to consider bed joint reinforcement also under and over the

openings. Reinforced masonry, where the reinforcement is intended to improve the structural performance of

the walls, will perform better with respect also to the normal movements, without the use of any additional

reinforcement. Adverse effects of movement will be minimised also by protection from extremes of moisture

in storage of the units and before, during and after construction of the walls. In addition, the weakest

recommended mortar and concrete mix, consistent with the structural and durability requirements, should

also be used for this purpose [Beall, 2004; Gambi et al. 1999].

The types of reinforced masonry covered by these guidelines are generally intended to be plastered or

rendered. When plastering the walls using general purpose mortar, conventional thicknesses should be

used. Normally the render should be applied in two-coats with the second coat being slightly weaker than the

first. Strong render mixes should be avoided. The suction of dry surfaces should be adjusted with water or a

bonding agent may be used. When plastering or rendering on walls built using general purpose mortar, the

mortar joints should be raked back or pointed to provide an additional key for the plaster or render. When the

masonry has been laid in thin-layer mortar, if it is provided with smooth or lightly textured surface, sprayed

thin layer renders and plasters which reduce completion times may be used [Beall, 2004].

The height of masonry to be built in one day should be limited so as to avoid instability and overstressing of

the fresh mortar. The wall thickness, the type of mortar, the shape and density of the units and the degree of

exposure to the wind should be taken into account in determining an appropriate limit. Units, mortar, grout

and reinforcement should be strictly in accordance with the corresponding specifications [Lawrence, 2001].

5.2 REINFORCEMENT, TIE, AND ANCHOR INSTALLATION

The bed joint reinforcement, the vertical reinforcement and any tie and anchor should be built in as work

proceeds in accordance with the drawings, specification and requirements of the design. Reinforcement and

other metal elements should be protected by a minimum 15 mm mortar cover at exterior joint faces. This

value changes and increases with environmental exposure classes, cement content, water/cement ratio and

size of aggregates in mortar and grout according to the minimum recommended covers given in EN 1996-1-

1. When using unprotected steel a minimum distance from the external face of the wall of about 50 mm

should be considered, taking into account also the plaster and rendering layers. To take into account the

durability issues, the use of corrosion resistant elements could be considered or should be preferred. The

distance from the face of the walls is also needed to protect the metal from fire exposure. The reinforcement

should be properly spaced and placed into the mortar or grout, and should have a certain minimum

clearances with the units, to ensure that complete embedment and good bond are obtained. For horizontal

bed joint reinforcement in general purpose and lightweight mortars, the EN 1996-1-1 recommends a mortar

cover to the face of masonry of at least 15 mm and a mortar cover below and above the reinforcement at

least 5 mm greater than the diameter of the reinforcing steel, in order to achieve bond strength to develop

(Fig. 1). For vertical reinforcement, an adequate dimension of the vertical cavity where the reinforcement is

placed, in order to ensure that mortar or grout can easily flow around, should be provided. In general, when

the holes have common dimensions (they are not large hollows), it is also recommended to avoid excessive




reinforcement diameter, more than 20 mm wide. According to EN 1996-1-1, the minimum dimension all

around a single bar should be 20 mm or the diameter of the bar, whichever is greater. For prefabricated

reinforcement, adequate solutions should be provided by the manufacturer.

Vertical reinforcement should restart from foundations (Fig. 3) or tie-beams (Fig. 7) at different floor levels.

Placing the vertical reinforcement into holes drilled into the concrete slabs (Fig. 8) and using special resins

to fix the reinforcement to the horizontal structures avoid possible mistakes in the positioning of the

reinforcement, but does not assure that the strength of the connection allows reaching the yield strength of

steel during extreme events such as earthquakes. This solution should be therefore avoided or adequately

tested before its use, considering the use of deep holes, cleaned with compressed air to remove dust, and

using high strength, expansive resins [Canal, 2006]. Specific recommendations provided by the resins

producer should be followed for what concern not only the depth of the holes, but also their diameter

compared to the reinforcement diameter, the distance between centres of close reinforcement and the

distance to the concrete element edge. Alternative solutions are based on the use of special fasteners such

as metal plates that should be fasten to the concrete slabs through screw or bolts and from which the vertical

reinforcements can be positioned. In case of truss type reinforcements the connection (thread) with the metal

plates ( ) may be made only at the longitudinal bars.

Fig. 7: Reinforcement restarting from the 1st

floor tie-beam

Fig. 8: Drilling the holes for the vertical

reinforcement

The vertical reinforcement should be placed before pouring the mortar or grouting. When the vertical

reinforcement is placed, the construction of the wall can be based on units with large or small holes, which

are threaded over the top of the bar, open-end units so that the unit is placed around the vertical steel, or

units with special recesses in the head joints for the construction of masonry around the reinforcement. In

the first case, the installation of the units around the vertical reinforcement traditionally requires that the

vertical reinforcement does not have a particular length (height should be not greater that the masons’

height), and require the mason to lift the units up to the reinforcement height and subsequently lower it to the

level of the last course of units built (Fig. 9). One or several reinforcement overlapping should be used,




according to the wall height. The overlapping of the reinforcement should be calculated according to the EN

1996-1-1, and can be generally equal to 60 diameters (Fig. 10) [DM 14/01/08]. This solution raises some

issues on the safety of the construction site operations, because of the need to raise the units, and on the

effectiveness of the reinforcement, due to possible inaccuracies in the overlapping. The use of open-end

units makes the construction easier, more precise and makes it possible to use storey-height reinforcement

in the construction (Fig. 11). In both cases, the vertical cavities should be filled with mortar as soon as the

work proceeds, that means course by course and, in any case, after the erection of no more than three

courses, in order to provide sufficient compaction of the mortar around the steel and in the voids [Canal,

2000; Gambi et al., 2003]. In case of concrete units the vertical reinforcements can be placed into a

continuous vertical joint when two cell units are sued or in case of three cell units in special recesses at the

end of the units, see Fig. 12. In both cases, the filling of the vertical joint with mortar should be carried out at

each course. When the construction foresees the incorporation of damp proof course membranes, the

vertical reinforcement should not be interrupted at the level of the membranes. Bar positioners can be

required at periodic intervals to hold the reinforcing bars in vertical alignment.

Fig. 9: Installation of the units from the top of the reinforcement

Fig. 10: Overlapping of the vertical reinforcement

Fig. 11: Installation of the units around the vertical

reinforcement

Fig. 12: Use of units with special recesses in

the head joints

The horizontal reinforcement should be completely embedded in mortar. The horizontal reinforcement that

acts as shear reinforcing steel should be anchored around the vertical members, and works as a stirrup, in

order to obtain the proper structural behaviour for which the shear walls are designed. The distance from the

faces of the walls, in the case of the horizontal reinforcement, is needed not only for durability issues, but

also, with respect to the indoor environment of the building, to allow some clearances for the creation of

small chases [AA.VV., 1996]. For masonry laid with general purpose mortar, the horizontal reinforcement

should be fully embedded into the mortar. Start with laying a first bed of mortar, place and print the

reinforcement in the mortar bed. Continue with the placing of the second layer of bricks on this mortar bed.

Bar positioners or simpler drops of mortar can be required to hold the horizontal reinforcement slightly lifted

from the unit, in order to achieve the embedment of the horizontal reinforcement once the bed joint is laid.




Otherwise it is possible to lay the bed joint and then, with a light pressure of the fingers, the horizontal

reinforcement is pushed into the bed joint itself. When using thin layer mortar, two layers of mortar (under

and above the bed joint reinforcement) will be needed to ensure a full embedment of the reinforcement

In general, the horizontal bed joint reinforcement should cover the length of the masonry wall. When this is

not possible, proper overlapping should be provided in order to avoid discontinuity. Specially designed units

that can accommodate the horizontal reinforcement, without the need of spacers and without paying

particular attention to the distance from the face of the wall, can be used. According to the EN 1996-1-1, the

bed joint reinforcement should be of small diameter (around 5 mm), in order to fit into the bed joints and,

moreover, to allow for easy bending of the reinforcement at the edges, corners, or around the vertical

reinforcement. In general, the bed joint reinforcement is not placed at each bed joint, but very often it is

placed any other joint. Therefore, it could be convenient, in case of convergent walls (corners or

intersections), to place the horizontal reinforcement into the first bed joint along all the walls, and then into

the even courses of one wall, and into the odd courses of the other wall, in order to avoid the overlapping of

the reinforcement at the corners or intersections [Zanarini, 2000].

Fig. 13: Horizontal reinforcement around the

vertical reinforcement, lifted from the units by means of mortar drops, and reference lines.

Fig. 14: Horizontal reinforcement below an opening.

5.3 GROUT PLACEMENT

The casting of the Self-Compacting Concrete should be carried out like with a conventional concrete using a

bucket or a concrete pump. The maximum head for a free fall of the concrete is 2,0 m. If the head is more

than 2,0 m a hose must be used. The wall should be filled with a constant filling height in each channel.

Because of the concrete pressure the maximum height of the wall must be considered.

5.4 TEMPORARY BRACING

Reinforced masonry under construction must be braced or otherwise stabilised as necessary to resist wind

and other lateral forces or possible loads arising either accidentally or from construction activities, without




impairing the structural integrity. It is left to the builder or designer to determine how this should be done in

each particular case. Bracing should be provided until the mortar has cured and the wall has been integrally

tied to the structural frame of the building. Once mortar joints have hardened, masonry develops a certain

level of bond strength quite quickly. It is probably reasonable (and conservative) to assume that masonry has

no bond strength for the first three days, then 50 per cent of its full strength up to an age of seven days. On

this basis it is possible to calculate safe working heights for unbraced masonry, taking into account wind

loading for the height of building, region, topography, etc [Lawrence, 2001].

5.5 TOLERANCES

Tolerances are necessary to allow for inevitable variations in the size of masonry products and inaccuracies

in construction techniques. For any masonry construction, location of elements in plan and elevation,

dimensions, deviation from plumb and from horizontal, planeness, thickness of bed and head joints, width of

cavities, location of reinforcing bar, should be checked as the work proceeds [Lawrence, 2001]. Deviations of

the built masonry should not exceed the values given in the EN 1996-2, and the values eventually given in

the design specifications. The EN 1996-2 recommends maximum vertical deviations of 20 mm in any one

storey, of 50 mm in the total height of a building of three storeys or more and maximum deviation of 20 mm

in the vertical alignment. The recommended straightness deviation is 10 mm in any one meter and 50 mm in

10 meter of wall. The first course of masonry should not overhang the edge of a floor or foundation by more

than 15 mm, even if this requirement is tighter for reinforced masonry where also the alignment of the vertical

reinforcement has to be taken into account. Fig. 15 explains the meaning of the vertical deviations.

Fig. 15: Maximum vertical deviations (after EN 1996-2)

Unit masonry size tolerances are accommodated by varying the thickness of the mortar joints. Common units

to be laid in general purpose mortar foresees the use of joint from 5 mm up to 15 mm thick, whereas units

with small dimensional tolerance in height are to be laid with thin layer joints, having thickness between 0,5

mm and 3 mm. For reinforced masonry made with hollow units, the Masonry Standards Joint Committee




(2005) specifications allow, for the placement of the vertical steel reinforcement, the maximum tolerances of

about 12.5 mm when the distance from the centreline of steel to the opposite face of masonry is equal or

lower than 203 mm, of about 25 mm when the distance is between 203 mm and 610 mm, and the maximum

tolerances of about 32 mm when the distance is greater than 610 mm. Most practical cases are contained in

the first two limitations. In the case of reinforced masonry made with perforated units, which contain relatively

small holes and where the minimum dimension all around a single bar should be 20 mm (or the bar

diameter, whichever is greater), the tolerances for the placement of the vertical steel reinforcement are not

given, but it is obvious that they are significantly lower than in the previous case, and reasonably contained

in few millimetres. For the horizontal bed joint reinforcement, the use of prefabricated reinforcement

facilitates its correct positioning in the bed joint. Tolerances are allowed for the placement of the horizontal

steel reinforcement made of two separate rebars, provided that the two rebars are placed at a distance of at

least one half of the wall thickness, and provided that they are at least 15 mm or more far from the unit

surface (and more from the finished wall face) in order to protect the reinforcement from corrosion (see §3.5).

It is very important to ensure complete embedment of the steel within the grout or mortar, so that full strength

is developed and durability is improved. It is also very important to provide adequate reinforcement

overlapping. To assure that the reinforcement is not displaced during the filling with mortar or grouting

operation, specific reinforcing bar spacers or special units that hold the steel in place can be used.

5.6 PROJECT CONDITIONS

During the works, construction loads that exceed the safe superimposed load-carrying capacity of the

masonry and shores, if used, should be avoided. Particular care should be paid to the masonry, as it will not

develop its full load bearing capacity until the mortar has cured, the wall has been connected to intersecting

walls and the top support (roof or floors) has been installed (see §5.4). The masonry should not be subjected

to any load until it has gained sufficient strength to carry this load safely [Lawrence, 2001].

Throughout the construction period, masonry and built-in elements should be protected to avoid damage and

surface contamination. During wet weather the top of unfinished masonry work should be covered to prevent

rainwater entering the units, which could lead to damage, excessive shrinkage and efflorescence. Cover can

be constituted by water repellent tarps or heavy plastic sheets, extending at least three masonry courses or

about half meter each side of the wall and held securely in place. Extreme wheater conditions such as cold,

hot and dry, freeze should be avoided during the execution of the work [Beall, 2004].

5.6.1 Cold weather construction

Cold weather causes problems in masonry construction. Construction may continue during cold weather,

however, if the mortar and grout ingredients, water sand and aggregates are heated (but not above 60°C)

and the masonry units and structure are protected during the initial hours after placement.

Even though sufficient water may be present, cement hydration and strength development in mortar and

grout will stop at temperature around 0°C. Mortar and grout mixed using cold but unfrozen ingredients have




different plastic properties, longer setting and hardening times, higher air content and lower early strength.

During cold weather construction, it may be desirable to use high-early-strength cement. During freezing

weather, low moisture contents are desirable, but mortar and grout consistency must maintain good

workability and flow. The use of additives has to be carefully evaluated. Antifreeze additives, if used in great

quantities, will also decrease the compressive and bond strength. Accelerators can contain calcium chloride

that has a highly corrosive effect on metal reinforcement and accessories. Their salt content may also

contribute to efflorescence and cause spalling of the units.

Cold masonry units exhibit the same performance characteristics of heated units except that the volume is

smaller and the potential for thermal expansion within the wall is greater. Attention should be paid to dry,

cold units that will withdraw water and heat from the mortar, decreasing in the first case, and increasing in

the second case, the rate of freezing. Units having either a temperature below 0°C or containing frozen

moisture, visible ice or snow on their surface should not be laid or should be heated and thawed without

overheating and using methods that do not result in damage. The same care should be taken with existing

foundations or masonry prior to receiving new construction or prior to grouting.

The rapidity with which masonry freezes is influenced by the severity of ambient temperature and wind, the

temperature and absorption characteristics of the units, the temperature of reinforcing steel and metal

accessories, and the temperature of the mix itself at the time of placement. During the construction, wind

breaks or enclosure and heating systems may be used. During the initial hours after placement the newly

constructed masonry should be protected, covered and in certain cases also heated to allow for proper

mortar and grout hardening and masonry curing. The degree of protection against severe weather which is

provided for the work area is an economic balance between mason productivity and cost of the protection.

Each protective measure should be evaluated individually to determine needs and cost benefits [Beall,

2004]. A detailed list of protective measures to be taken according to the temperature is contained in the

Masonry Standards Joint Committee (2005) specifications for masonry structures.

5.6.2 Hot weather construction

High temperatures, low humidity and wind can also adversely affect performance of the masonry, as the

rapid evaporation and the high suction of hot, dry units can reduce the water content of mortar and grout

mixes so that cement hydration actually stops. When the temperature condition raise above 30°÷40°C, and

particularly in the case of windy weather, protective measure should be taken to assure continue hydration,

strength development and maximum bond. Materials should be stored in a shaded location, and if mortar is

not premixed, sand and aggregates should be covered with black plastic sheets to retard moisture

evaporation. High-suction units should be wetted to reduce initial absorption and reinforcing steel and metal

accessories can be kept cool by spraying with water. Additional mixing water may be needed in mortar and

grout, but this changes the mechanical properties of the resulting admixture. Additional lime content will

increase water retentivity, whereas increased cement content accelerates early strength gain and maximizes

hydration before evaporative water loss, even if it will increase the temperature. Set retarding or water-

reducing additives may be also used.




During the construction, sun shades and wind screens can modify the effects of hot, dry weather, but

consideration should be also given to scheduling work during the cooler parts of the day. During the first

three days after placement, the newly constructed masonry should be fog sprayed until damp, at least three

times a day. Covering the walls with plastic sheets will also retard evaporation and aid the moist curing of the

masonry [Beall, 2004]. A detailed list of protective measures to be taken according to the temperature is

contained in the Masonry Standards Joint Committee (2005) specifications for masonry structures.




6. QUALITY ASSURANCE MEASURES AND POST-CONSTRUCTION

Not all masonry projects will involve testing or inspection. However, site control and inspections shall be

carried out to ensure that the construction complies with the provisions set out in the design. Where doubt

exists that the required properties are being achieved, specimens representative of the masonry should be

made up and assessed for compliance with requirements of the design, and appropriate action shall be

taken. An established quality assurance program typically includes inspection of the work by an owner's

representative and the periodic sampling and testing of masonry materials, to provide assurance that

materials and workmanship are in accordance with the design specifications. The quality objectives are met

when the building is properly designed, completed using materials complying with product specifications

using adequate construction practices, and is adequately maintained after the construction. Inspections and

testing are important components of the quality assurance program, which is used to meet the objective of

quality in construction [ACI 530-05/ASCE 5-05/TMS 402-05, 2005].

6.1 INSPECTIONS

The masonry inspector's job is to obtain good quality masonry construction and workmanship according to

plans and specifications. Inspections consist in the observing of the construction process to confirm that it

complies with the design plans and the specifications. The inspector should be able to explain the reasons

for the specified procedures and know the important aspects of quality workmanship that will produce

reinforced masonry elements with the properties assumed in the structural design [Schneider and Dickey,

1980].

Job should not start unless all the materials have been supplied and everything is on hand. Foundations,

beams, floors, and other structural elements that will support the masonry should be checked for completion

to proper line and grade before the works begins. Overall dimensions and layout must be verified against the

drawings and field adjustments made to correct discrepancies [Beall, 2004].

During the reinforced masonry construction, the type and positioning of wall ties, bar positioners, joint

reinforcement, vertical reinforcement and the presence of clean spaces around the reinforcement should be

verified against the project drawings and specifications, also in relation to the problems of cover for durability

and full embedment in mortar or grout for the development of bond strength. The length and proper

execution of overlapping, anchorages and other reinforcement details should be checked.

During the grouting process, the inspector should verify that the grout is proportioned properly, the proper

grouting technique is used, and all grout spaces are completely filled with grout. During the laying of mortar

joints, the inspector should verify that the mortar is proportioned properly, the reinforcement is fully

embedded with mortar and the joints are properly covered and made with the correct thickness. The

inspector should verify that the masonry walls are built within the allowed tolerances (see §5.5). Other

details, such as proper execution of wall corners and intersections, correct positioning of lintels and other

ancillary components, correct connection between walls and floors should be also checked.




Bracing and shoring should be inspected for proper installation, also to ensure the minimum requirement for

the safety of the site job (see §5.4). Protection measures such as covering the tops of uncompleted work,

heated enclosures, and insulation blankets should be verified. If the construction is made during extreme

(cold or hot) wheater conditions, the inspector should verify that all the necessary measures are taken to

avoid alteration of the cement hydration procedure, etc [Beall, 2004].

A written report should be made and provided to the designers for each day that an inspection is made. Any

deficiencies that are uncovered should be reported to the builders and designers. Corrections to any

deficiencies should be noted in subsequent reporting. At the completion of the project the inspector and

contractor should make a final report certifying compliance.

For residential buildings, inspections could be carried out at times. For industrial and commercial buildings, a

program of periodic inspections may be acceptable, while for institutional buildings continuous inspection is

probably more appropriate, regardless of code requirements [Sebastian, 1998].

6.2 TESTING

On some reinforced masonry projects, but not in all, it may be necessary to conduct various quality control

tests, both in laboratory and on-site, to ensure that the masonry has been constructed properly. The

frequency of testing should be stated in the project specifications, if it is not required by design standards.

Testing may be conducted prior to or during construction on the individual materials, e.g. units, mortar,

reinforcement and grout. This is the most common form of quality control testing, even if most of these

products now require the EC marking to be sold, and therefore their properties should be stated by the

producer. Units are typically tested for compressive strength. Mortar may be tested in compression prior to

construction in order to establish proportions of ingredients to be measured at the jobsite or after

construction on samples taken during the construction. The same is true for grout. Mortar could be also

tested to verify the consistence, in particular in those projects where mortar is used also to fill the vertical

cavities, and grout should also be tested to verify the slump. The materials and the test methods for

evaluating them are described into the relevant standards and specifications that are listed in section 3.

Also assemblage quality control tests may be required for masonry elements. The main mechanical

properties of masonry are obtained by means of testing as required by the EN 1996-1-1 and as described in

the EN 1052 test series. Some special tests may not be covered by the EN 1052 test series, a list of the

main cyclic in-plane and out-of-plane testing methods and their recent developments in contained in the

deliverable D5.1. Masonry is generally tested to check the compressive strength and the modulus of

elasticity in compression. Other typical tests concern the evaluation of the shear strength and the bond

strength of the unit mortar interface or, in certain cases, the shear and flexural strength of masonry.

Finally, tests of samples extracted from the constructed masonry may be necessary to verify the strength of

elements when this is in question, only in very particular cases and when the structure is heavily damaged. A

prism cut out of a masonry element to be used for compression testing is an example of such a test.

Nowadays, quality control tests after the construction of the building, in order to verify the presence of defect

or the conformity of the construction to the design specifications can be carried out also by means of non-




destructive testing methods. These methods allow checking the structure without extracting any sample or

provoking any damage to the masonry elements.

Typical testing problems that may be solved by means of non destructive methods concerns the detection of

defects such as insufficient filling of vertical joints and block cells and of bed joints, delaminations and

detachments of the covering mortar layer, the detection and assessment of horizontal and vertical

reinforcement, the evaluation of the overlapping length. The testing techniques that were proposed to solve

these problems are generally based on the propagation of different types of waves in masonry, such as grout

penetrating radar, ultrasonic pulse velocity and sonic pulse velocity tests, impact echo methods.

Furthermore, the use of electromagnetic covermeters and of infrared thermography was also proposed.

However, each of these techniques present advantages and limitations and it should be noticed that

although several techniques are currently used, there is no a single technique that solves all problems. A

review of available non destructive techniques that could be used on reinforced masonry, their features,

method of application and available standards, is contained into the deliverable D5.2 and a review of their

actual performances as obtained from the application on real masonry walls and constructions is given by

the deliverables D5.6 and D7.4.

Quality control tests can seem an onerous and unwanted expense, but they are provided for some very

important reasons. First and foremost, tests can indicate consistency during construction. Dramatic changes

in strength properties of elements as the work progresses can indicate a problem and should be explained.

The second reason for testing is to monitor the strength gain of the masonry elements upon curing. The

strength gain is monitored to indicate when shores or bracing can be removed, when loads can be applied to

an element, and to verify that the strength assumed in the design has been achieved by the constructed

masonry. Finally, non destructive testing allow to gain important information on the existing constructions,

check their conformity with the original design specifications to enhance the confidence level and solve

eventual disputes, without causing damage to the constructions.

Regarding the products contained also in section §3, the CE marking provides the contractor and client with

the test methods and the minimum quality requirements.

6.3 POST CONSTRUCTION AND MAINTENANCE

Completed buildings should be allowed to dry out gradually. Heating regimes should be applied gradually

and through ventilation maintained. Handover Documents should be passed to the client at the formal

handover. Ordinary maintenance practices should be kept in order to avoid untimely deterioration of the

construction [Aircrete Product Association, 2002].

When there is a problem, first, the problem should be identified and the cause of the problem should be

recognized. A masonry wall showing efflorescence, spalling, cracking or bulging usually indicates a concern

that must be addressed or at least acknowledged. The damage should not be repaired or the dirty cleaned

without locating the cause of the problem, or the same problem will be likely faced again, only more

accentuated or damaging. The cause of damage can be located by means of inspections and testing, in

order to check if the reinforced masonry walls were built as designed, the design was functional and the




cause of the damage is limited and can be localized or is diffused throughout the entire building. Also an

analysis of the source of the problem and its relationship to typical masonry criticalities should be made.

Some of these are, for example, movements (away from structure tied into the masonry wall, from lack of

deflection spaces, expansion or control joints, because of temperature/weather variations, etc.), moisture

(retention within the wall, impaired drainage, etc.), etc. Only after the proper identification of the damage and

its cause, the necessary adjustments, and/or corrections should be made [Sebastian, 1998].

It has to be highlighted that correct design and execution, according to standardized regulations and to

design and construction guidelines such as those given by the deliverable D6.2 and by the present

deliverable, ensure better behaviour and absence of defects and damage.

In case of any demolition, only properly supervised skilled and experienced operatives should carry out the

work. Demolition methods should not produce health hazards over and above the care needed to ensure the

stability of all parts of the building and the safety of all personnel in the vicinity of the demolition. Demolished

materials should be recycled wherever possible [Aircrete Product Association, 2002].




7. DETAILING

In the present section, a series of typical details for the construction of reinforced masonry walls made with

perforated clay units, large hollow clay units and large hollow concrete units is given. The list presented

hereinafter is not considered to cover all the possible solutions, but only to give a general overview of

standard, common solutions that can be used in practice.

7.1 REINFORCED MASONRY WITH PERFORATED CLAY UNITS

7.1.1 Reinforced masonry made with vertically perforated clay units

Fig. 16: Example of units. Left: horizontal cross section of typical H shape unit; center: horizontal cross section of new developed C shape unit; right: horizontal cross section of typical half unit.

Fig. 17: Details at wall intersection (two courses).




Fig. 18: Details at wall corner (two courses).

Fig. 19: Details at the openings (three courses).




7.1.2 Reinforced masonry made with horizontally perforated clay units

Fig. 20: Example of units. Left and centre: horizontal cross section of the special units for the vertical

confining columns; right: plan view and vertical cross section of the horizontally perforated unit.






Fig. 23: Details at the openings (three courses).




7.2 REINFORCED MASONRY WITH LARGE HOLLOW CLAY UNITS

Fig. 24: Reinforcement system with overlapping in vertical and horizontal direction

Fig. 25: Detail of the vertical reinforcement and horizontal cross section of masonry




Fig. 26: Erection of the masonry walls (no reinforcement shown) with thin layer mortar using roller for the mortar application - connection with transversal wall using additional perforated steel plates

Fig. 27: Detail of the reinforcement placed into the units in each layer

Fig. 28: Additional horizontal reinforcement bars in the crossing area of longitudinal and transversal wall




7.3 REINFORCED MASONRY WITH LARGE HOLLOW CONCRETE UNITS

(a)

(b)

Fig. 29: Geometry of the three cell concrete units (real scale geometry); (a) block and ½ half block; (b) lintel block




8. EXAMPLES

In the present section, some examples of real buildings made with reinforced masonry walls made with

perforated clay units, large hollow clay units and large hollow concrete units is given. The list presented

hereinafter is not considered to cover all the possible building typologies, but only to give a general overview

of the possibilities of the studied systems.

8.1 REINFORCED MASONRY BUILDINGS WITH PERFORATED CLAY UNITS

8.1.1 Residential buildings

Fig. 32: One-family house in San Gregorio

nelle Alpi (BL, Italy). Fig. 33: Two-family house in Peron di Sedico

(BL, Italy).

Fig. 34: Multi-family house in San Mauro a

Signa (FI, Italy). Fig. 35: Eight row houses in Alberi di Vigatto

(PR, Italy).




Fig. 36: Multi-family house in Villa Canali di Albinea (RE, Italy).

Fig. 37: 58 flats for public housing in Colle

Aperto (MN, Italy). Fig. 38: Tourist village in Puegnano del

Garda (BS, Italy).

Fig. 39: Residential complex in Colle Aperto

(MN, Italy). Fig. 40: Residential complex (11 buildings) in

Lunetta - Frassino (MN, Italy).




8.1.2 Service, commercial and industrial buildings

Fig. 41: Nursery school in Parma (Italy). Fig. 42: Sport centre in Reggio Emilia (Italy).

Fig. 43: Hotel in Castelvetro (MO, Italy). Fig. 44: Wine growsers’ cooperative in Pratissolo di Scandiano (RE, Italy).

Fig. 45: Cheese factory for the Production of Parmigiano Reggiano in Ramiseto (RE, Italy).




8.2 REINFORCED MASONRY BUILDINGS WITH HOLLOW CONCRETE UNITS

Fig. 46: Example of a typical building with reinforced concrete masonry

Fig. 47: Example of a structural concrete masonry residential house in Lisbon

Fig. 48: Example of reinforced concrete walls at bed joints (Sporting Stadium, Lisbon)




Fig. 49: Example of reinforced concrete walls at bed joints (SLBenfica Stadium, Lisbon)




REFERENCES

ACI 530-05/ASCE 5-05/TMS 402-05 (2005). “Building code requirements for masonry structures” Masonry

Standards Joint Committee

AIRCRETE PRODUCT ASSOCIATION (2002) “Code of best practice for the use of aircrete products”,

downloadable from http://www.aircrete.co.uk/pdfs/guide_bestpractice.pdf

AMRHEIN J.E. (1998). “Reinforced masonry engineering handbook”, Masonry Institute of America & CRC

Press, Boca Raton, New York

AA.VV. (1992) “Masonry Structural Design for Buildings”, Publication Number: TM 5-809-3; Departments of

the Army (Corps of Engineers)

AA.VV. (1996) “Ricerca all'I.T.E.A. e progetto "BRITE" ”, Murature Oggi, n. 53, 31/12/1996, (In Italian)

AA.VV. (1999) “La muratura armata in zona non sismica”, Murature Oggi, n. 62, 31/03/1999, pp.25-29 (In

Italian)

BARI L., ZANARINI G. (2006) “La muratura armata”. Costruire in laterizio, Faeza Editrice, n. 110,

Marzo/Aprile 2006, pp. 56-59 (In Italian)

BEALL C. (2004). “Masonry design and detailing: for architects and contractors”, McGraw-Hill, New York.

Jaffe R. C. (2004). “Masonry instant answers”, McGraw-Hill, New York.

BS 5628-1 (2005). Code of practice for the use of masonry – Part 1: Structural Use of unreinforced masonry

BS 5628-2 (2005). Code of practice for the use of masonry – Part 2: Structural Use of reinforced and

prestressed masonry

BS 5628-3 (2005). Code of practice for the use of masonry – Part 3: Materials and components, design and

workmanship

CANAL N. (2000) “Realizzazione di un fabbricato ad uso civile abitazione in Muratura Armata”, Murature

Oggi, n. 67, 30/06/2000, pp.42-48 (In Italian)

CANAL N. (2006) “Costruzione di un fabbricato plurifamiliare in muratura armata”, Murature Oggi, n. 90,

31/03/2006, pp.29-42 (In Italian)

DELIVERABLE D3.1 (2006) “Report about the requirements for masonry units, reinforcement, mortar and

concrete“. Issued by RWTH. DISWall, COOP-CT-2005-018120

DELIVERABLE D5.1 (2006) “Report about the existing methods for cyclic in-plane and out-of-plane testing

and their development for the project aims”. Issued by UMINHO. DISWall, COOP-CT-2005-018120

DELIVERABLE D5.2 (2006) “Review on the NDTs for inspecting masonry walls” Issued by UMINHO.

DISWall, COOP-CT-2005-018120

DELIVERABLE D5.6 (2007) “Technical report with the experimental results of NDE methods applied to

masonry walls“. Issued by UMINHO. DISWall, COOP-CT-2005-018120

DELIVERABLE D6.2 (2007) “Guidelines on the design for end-users“. Issued by TUM. DISWall, COOP-CT-

2005-018120

DELIVERABLE D7.4 (2007) “Report on in situ testing, with definition of NDE methods for quality control and

on adequacy of the execution technology”. Issued by CISEDIL. DISWall, COOP-CT-2005-018120




DM 14/09/2005 (2007). Technical Standards for Constructions. (and subsequent updating, 27/07/2007; in

Italian)

EN 197-1 (2007). “Cement - Part 1: Composition, specifications and conformity criteria for common cements”

EN 206- 1 (2005). “Concrete - Part 1: Specification, performance, production and conformity”

EN 459-1 (2002). “Building lime - Definitions, specifications and conformity criteria”

EN 771-1 (2005). “Specification for masonry units - Part 1: Clay masonry units”

EN 771-3 (2005). ”Specification for masonry units - Part 3: Aggregate concrete masonry units (Dense and

light-weight aggregates)”

EN 845-1 (2003) “Specification for ancillary components for masonry - Ties, tension straps, hangers and

brackets”

EN 845-2 (2003) “Specification for ancillary components for masonry – Lintels”

EN 845-3 (2003) “Specification for ancillary components for masonry - Bed joint reinforcement of steel

meshwork”

EN 934-3 (2003). “Admixtures for concrete, mortar and grout - Admixtures for masonry mortar - Part 3:

Definitions, requirements, conformity, marking and labelling”

EN 1052 series (various years) “Methods of test for masonry”

EN 1086 (2006). “Chimneys - Clay/ceramic flue blocks for single wall chimneys - Requirements and test

methods”

EN 1992-1-1 (2004). “Eurocode 2 - Design of concrete structures - Part 1-1: General rules and rules for

buildings”

EN 1996-1-1 (2005). “Eurocode 6 - Design of masonry structures - Part 1-1: General rules for reinforced and

unreinforced masonry structures”

EN 1996-2 (2006). “Eurocode 6 - Design of masonry structures - Part 2: Design considerations, selection of

materials and execution of masonry”

EN 1998-1 (2004). “Eurocode 8 - Design of structures for earthquake resistance - Part 1: General rules,

seismic actions and rules for buildings”

EN 10080 (2005). “Steel for the reinforcement of concrete - Weldable reinforcing steel – General”

EN 13139 (2004). “Aggregates for mortar”

GAMBI A., LENZI M., OLIVUCCI G. (1999) “Realizzazioni di murature armate in zone non sismiche”,

Costruire in laterizio, Faeza Editrice, n. 72, Novembre/Dicembre 1999, pp. 60-64 (In Italian)

GAMBI A., LENZI M., OLIVUCCI G. (2003) “L’impiego delle murature armate”, Murature Oggi, n. 81,

31/12/2003, pp.30-36 (In Italian)

LAWRENCE S. (2001). “Construction Guidelines for Clay Masonry”, Clay Brick and Paver Institute,

Baulkham Hills, Australia, downloadable from http://www.thinkbrick.com.au/index.cfm?66F69F44-EE34-

C88B-8B8F-141E78E86E7A&search_option=technical_manuals

OPCM 3431 (2005). Technical Standards for the seismic design, evaluation and upgrading of buildings. (in

Italian)

SCHNEIDER R.R., DICKEY W.L. (1980). “Reinforced masonry design”, Prentice-Hall Inc., Englewood Cliffs,

New Jersey




SEBASTIAN A. (1998) “Building pathology & construction technology, architecture, civil, structural, forensic,

mechanical, pavement and materials engineering with elements of testing and quality science technical

glossary” downloadable from http://www.angelfire.com/biz/BuildingPathology/BldngPathGlsry.html

TUBI N. (1981). “La realizzazione di murature in laterizio”, Edizioni Laterconsult, Roma (in Italian)

ZANARINI G. (1999) “Guida: costruire in muratura armata”, downloadable from

http://www.muraturaarmata.it/articoli.htm , (In Italian)

ZANARINI G. (2000) “La muratura armata”, Costruire in laterizio, Faeza Editrice, n. 76, Luglio/Agosto 2000,

pp. 65-71 (In Italian)




ANNEX: NETWORK OF EXPERTISE ON REINFORCED MASONRY

N. Country Name Field of expertise Contact e-mail / website

Australia

Australian Clay Brick and Paver manufacturers -

Think Brick

Clay unit masonry

PO Box 6567, Baulkham Hills; BC NSW 2153; Tel. + 61 2 9629 4922

Fax + 61 2 9629 7022

[email protected] www.thinkbrick.com.au

Austria Verband

Österreichischer Ziegelwerke

Clay unit masonry

Wienerberg City Wienerbergstrasee 11; A-1100 Vienna Tel.:(43-1) 587 33 46 0 Fax:(43-1)

587 33 46 11

[email protected] www.ziegel.at

Belgium WTCB-CSTC

Federation belge de la brique

Clay unit masonry

Rue des Chartreux 19, Bte 19; B-1000 Bruxelles

Tel.:(32-2) 511 25 8 Fax:(32-2) 513 26 40

[email protected] www.brique.be

Bulgary Bulgarian Ceramists Union

Clay unit masonry

Alabin Street 36; BG-1000 SOFIA

Tel: (359-2) 980 60 22Fax:(359-2) 980 60 15

//

Canada Canada Masonry Centre

All types of masonry

360 Superior Blvd. Mississauga ON Canada L5T 2N7

Tel: (905) 564-6622 Fax: (905) 564-5744

www.canadamasonrycentre.com

Canada

The Brick Industry

Association (BIA)

Clay unit masonry

1850 Centennial Park Drive, Suite 301, Reston,

VA 20191 Tel: 703.620.0010 Fax:

703.620.3928

[email protected] www.brickinfo.org/

Canada

National Concrete Masonry

Association (NCMA)

Concrete unit

masonry

13750 Sunrise Valley Drive Herndon, VA

20171-4662 Tel: 703.713.1900 Fax:

703.713.1910

[email protected] www.ncma.org

Czeck Republic

Cihlarsky Svaz Cech Moravy

Clay unit masonry

Nové Homole 61; CZ-370 01 Ceské Budejovice

Tel (420-38) 725 06 09 Fax:(420-38) 725 06 09

//

EU

European Autoclaved

Aerated Concrete

Association

AAC masonry

Entenfangweg 15 30419 Hannover

Tel. +49 511 39 08 97-7 Fax +49 511 39 08 97-90

[email protected] http://www.eaaca.org

Finland Finnish Brick

Industry Association

Clay unit masonry

c/o Finnish Ass. of Construction Product Ind.,

P.O. Box 381; 00131 Helsiniki

Tel:(358-9) 17 28 44 31 Fax:(358-9) 17 28 44 44

//

France

CSTB Federation

Francaise Des Tuiles Et Briques

Clay unit masonry

17, rue Letellier; F-75015 Paris Tel.:(33-1) 44 37 07

10 Fax:(33-1) 44 37 07 20

[email protected] www.fftb.org

Germany

Bundesverband Der Deutschen

Clay unit masonry

Schaumburg-Lippe-Strasse 4; D-53113

[email protected] http://www.ziegel.de




Ziegelindustrie e.V.

BONN Tel (49-228) 914 930Fax:(49-228) 914 93 28

Greece Association

Greek Heavy Clay Industries

Clay unit masonry

Tavaki 4 A; GR-57001 Thermi Thessaloniki –

Greece Tel: +30 23 10 48 95 75 Fax: +30 23 10 48 95 75

[email protected] www.sevk.gr

Italy Consorzio Alveolater

Perforated clay unit

reinforced masonry

viale Aldo Moro, 16; 40127 Bologna Tel. 051 509873 Fax 051 509816

[email protected] www.muraturaarmata.it/

Italy Consorzio

POROTON® Italia

Perforated clay unit

reinforced masonry

Via Gobetti, 9; 37138 VERONA

Tel. 045/572697 Fax 045/572430

[email protected] www.poroton.it

Italy ANDIL Assolaterizi

Clay unit masonry

Via A. Torlonia 15; 00161 ROMA

06 44236926 06 44237930

[email protected] www.laterizio.it/

Italy

Associazione Nazionale

Produttori Argille Espanse

A.N.P.A.E.

Expanded clay unit masonry

Via Correggio, 3 - 20149 – Milano

Tel. 02.48011962 - Fax. 02.48012242

[email protected] www.anpae.it/

The

Netherlands

Stichting stapelbouw

Knb - Koninklijk Verbond Van Nederlandse

Bak-Steenfabrikanten

Clay unit masonry

TU Eindhoven Postbus 153; NL-6880 Ad

Velp (Gld.) Tel.:(31-26) 384 56 30Fax:(31-26) 384 56 31

[email protected] www.knb-baksteen.nl

New Zealand

New Zealand Concrete Masonry

Association (NZCMA)

Concrete unit

masonry // http://www.nzcma.org.nz/

Poland

Zwiazek Pracownikow

Ceramiki, Budowlanej I

Silikotow

Clay unit masonry

Ul. Mazowiecka 12; PL-00-926 Warszawa

Tel.: (48-22) 826 68 88 55 Fax:(48-22) 826 31 01

//

Portugal

APICER Associaçao

Portuguesa da Industria de Cerâmica

Clay unit masonry

Rua Coronel Veiga Simaö, Edificio C; P-

3020-053 COIMBRA Tel: (351-2) 39 497 600

Fax:(351-2) 39 497 601

[email protected] www.apicer.pt

Spain

HYSPALIT Asociacion

Española de Fabricantes de

Ladrillos y Tejas de Arcilla Cocida

Clay unit masonry

Orense 10 2; E-28020 Madrid

Tel.:(34-91) 770 94 80 Fax:(34-91) 770 94 81

[email protected] www.hispalyt.es

Switzerland

Verband Schweizerische Ziegelindustrie -

Vsz

Clay unit masonry

Elfenstrasse 19, Postfach; CH-3000 Bern 6 Tel.: (41-31) 352 11 88 Fax:(41-31) 353 11 85

[email protected]

www.domoterra.ch




UK Brick

Development Association

Clay unit masonry

Woodside House, Winkfield, Windsor, Berkshire, SL4 2DX.

Tel.: +44 1344 885 651 Fax: +44 1344 890 129

e-mail: [email protected] http://www.brick.org.uk

UK The British

Masonry Society (BMS)


Shermanbury 6 Church Road Whyteleafe Surrey

CR3 0AR Tel: +44 208 660 3633 Fax: +44 208 668 6983

http://www.masonry.org.uk/

US Masonry Institute of America (MIA)


22815 Frampton Ave. Torrance, CA 90501-5034 Tel: 1-800-221-4000

http://www.masonryinstitut

e.org/

US The Masonry Society (TMS)


3970 Broadway, Suite 201-D

Boulder, CO USA 80304-1135

[email protected] http://www.masonrysociety.

org

US International

Masonry Institute (IMI)


The James Brice House 42 East Street, Annapolis,

MD 21401 Tel.: (410) 280-1305 fax:

(301) -261-2855

[email protected]

www.imiweb.org

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