Precast and Tilt-up Concrete for Buildings · Precast concrete construction is a method of prefabricating concrete in discrete elements and erecting and incorporating them by crane

Industry Standard

Precast and Tilt-up Concrete for Buildings

Developing the standard in partnership

Foundations for Safety is Victoria’s primary forum for dealing with occupational health and safety issues in the construction industry.

Foundations for Safety has brought together State Government regulatory agencies, accidentresearch expertise, construction industry trade unions and employer associations representingprincipal contractors and construction sub-contractors. It meets in full session every three monthsand establishes working parties to progress various health and safety initiatives.

At the time of printing, the organisations represented on Foundations for Safety are:

• Australian Industry Group

• Australian Manufacturing Workers Union

• Air Conditioning and Mechanical Contractors Association

• Civil Contractors Federation

• CEPU Electrical Trades Union

• CEPU Plumbing Division

• CFMEU Construction and General Division

• CFMEU FEDFA Division

• Finishing Trades Association of Australia

• Housing Industry Association

• Master Builders Association of Victoria

• Master Plumbers & Mechanical Services Association of Australia

• Monash University Accident Research Centre

• National Electrical and Communications Association

• Office of the Chief Electrical Inspector

• Victorian Employers Chamber of Commerce and Industry

• Victorian Trades Hall Council

• Victorian WorkCover Authority

You can help improve health and safety in the construction industry by providing yourfeedback on this Industry Standard or on other health and safety issues to any of theFoundations for Safety member organisations.

WorkSafe Victoria Contacts

Head office24th Floor222 Exhibition StreetMelbourne VIC 3000

GPO Box 4306Melbourne VIC 3001Phone 9641 1555Fax 9641 1222Toll-free 1800 136 089

[email protected]

Websitewww.workcover.vic.gov.au/construction

Local officesBallarat 5337 1400Bendigo 5443 8866Dandenong 8792 9000Geelong 5226 1200Melbourne 9941 0500(628 Bourke Street)Mildura 5021 4001Mulgrave 9565 9444Preston 9485 4555Shepparton 5831 8260Traralgon 5174 8900Wangaratta 5721 8588Warrnambool 5562 5600

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Contents

Introduction

Part 1: General ......................................................... 11.1 Purpose......................................................................................... 11.2 Scope ........................................................................................... 11.3 Special provisions ............................................................................ 11.4 Exclusions ..................................................................................... 11.5 Relationship to Australian Standards ...................................................... 11.6 Referenced documents and further reading ............................................... 21.7 Definitions ..................................................................................... 21.8 Pre-planning and coordination .............................................................. 2

Part 2: Training and hazard management ............................. 32.1 General ......................................................................................... 32.2 Training ........................................................................................ 32.3 Health and safety ............................................................................. 42.4 Hazard management ......................................................................... 52.5 Incident notification .......................................................................... 6

Part 3: General design provisions...................................... 73.1 General ......................................................................................... 73.2 Building stability .............................................................................. 73.3 Specification of concrete ................................... ................................. 73.4 Structural design ............................................................................. 83.5 Loads .......................................................... ................................. 83.6 Element size and reinforcement ............................................................ 93.7 Joints .......................................................... ................................. 93.8 Composite construction .................................................................... 103.9 Connections .................................................................................. 103.10 Lateral restraint .............................................................................. 123.11 Tolerances .................................................................................... 133.12 Structural drawings .......................................... ............................... 143.13 Shop drawings ............................................................................... 143.14 Casting and erection sequences ........................................................... 14

Contents cont.

Part 4: Design for erection ............................................ 154.1 General ....................................................................................... 154.2 Planning ...................................................................................... 154.3 Shop drawings ............................................................................... 154.4 Loading ....................................................................................... 174.5 Composite construction ............................... ..................................... 184.6 Additional reinforcement .............................. ..................................... 184.7 Design for lifting ............................................................................. 194.8 Lifting inserts ................................................................................ 224.9 Strongbacks ................................................................................. 244.10 Slenderness effects ......................................................................... 244.11 Bracing and propping ....................................................................... 254.12 Bracing inserts .......................................... ..................................... 274.13 Brace footings .......................................... ..................................... 284.14 Special provisions ...................................... ..................................... 294.15 Erection design engineer’s certificate of compliance ................................... 30

Part 5: Manufacture................................................... 315.1 Pre-planning ................................................................................. 315.2 Shop drawings ............................................................................... 315.3 Casting and erection sequences ........................................................... 315.4 Formwork .................................................................................... 335.5 Tolerances .................................................................................... 335.6 Reinforcement................................................................................ 345.7 Lifting inserts............................................ ..................................... 345.8 Strongbacks ............................................. ..................................... 355.9 Concrete placement ......................................................................... 355.10 Minimum strength for lifting .......................... ..................................... 365.11 Curing and release ........................................................................... 365.12 Special provisions for on-site casting..................................................... 365.13 Release agents ............................................................................... 375.14 Stripping and repair ......................................................................... 375.15 Modification .................................................................................. 375.16 Element identification ....................................................................... 375.17 Manufacturer’s certificate of compliance ................................................. 37

Contents cont.

Part 6: Handling and storage ......................................... 386.1 General ........................................................................................ 386.2 Handling ...................................................................................... 386.3 Concrete strength for handling ............................................................ 396.4 Storage ......................................................... ............................... 396.5 Storage systems ............................................................................. 406.6 Site storage ................................................................................... 416.7 Impact protection ............................................................................ 41

Part 7: Transport ...................................................... 427.1 General ........................................................................................ 427.2 Basic principles .............................................................................. 427.3 Support frames .............................................................................. 437.4 Element protection........................................................................... 447.5 Delivery ....................................................................................... 44

Part 8: Erection ....................................................... 468.1 General ........................................................................................ 468.2 Planning the construction and erection sequence....................................... 468.3 Planning cranage requirements............................................................ 468.4 Operating near overhead power lines ...................... ............................... 478.5 Erection preparation......................................................................... 518.6 Crane capacity and operating radius ...................................................... 518.7 Erection crew................................................................................. 528.8 Erection platform ............................................................................ 538.9 Rigging ........................................................................................ 538.10 Strongbacks .................................................................................. 558.11 Erection sequence ........................................................................... 558.12 Erection of tilt-up panels .................................................................... 558.13 Erection of other precast elements ........................................................ 578.14 Levelling shims .............................................................................. 578.15 Fixing inserts ................................................................................. 598.16 Missing or unusable lifting inserts ........................................................ 598.17 Temporary bracing........................................................................... 59

Contents cont.

8.18 Temporary propping......................................................................... 618.19 Modifications ............................................ ..................................... 648.20 Compliance requirements .................................................................. 64

Part 9: Proprietary elements.......................................... 659.1 Application.................................................................................... 659.2 General design provisions .................................................................. 659.3 Design for erection .......................................................................... 659.4 Manufacture ............................................. ..................................... 659.5 Storage ........................................................................................ 669.6 Transport...................................................................................... 669.7 Erection ....................................................................................... 67

AppendicesA: Referenced documents and further reading.............................................. 69B: Definitions of terms used in this Industry Standard .................................... 72C: Erection design engineer’s certificate of compliance.................................... 76D: Manufacturer’s certificate of compliance ................................................. 77

Illustrations3.1 Threaded inserts ............................................................................. 113.2 Grout tube ............................................... ..................................... 134.1 Wall panel rigging............................................................................ 204.2 Shear loads and tension loads in edge-lifted panels .................................... 234.3 Panel rotation............................................ ..................................... 244.4 Panel bracing ............................................ ..................................... 275.1 Crane lifting radius........................................................................... 328.1 Clearance for cranes from overhead power lines........................................ 488.2 High voltage contact......................................................................... 508.3 Tailing lifters .................................................................................. 548.4 Levelling shims .............................................................................. 588.5 Uneven erection loading .................................................................... 62

Introduction

Precast concrete construction is a methodof prefabricating concrete in discreteelements and erecting and incorporatingthem by crane into their final position inthe building structure.

This document sets out industry-wideguidelines for establishing and maintaininga safe working environment whereverprecast and tilt-up concrete constructionis used.

The precast and tilt-up concrete industryshould be aware of the obligations toprotect employees and members of thepublic under the various Victorian acts,regulations and codes of practice madeunder legislation relating to health andsafety.

This industry standard provides practicaladvice about the safe design, manufacture,transportation and erection of precastconcrete and tilt-up concrete elements.The emphasis is on ensuring a safeworking environment whenever theseelements are used. It is not intended to bean all-encompassing design, manufactureand erection manual.

Advice on the general design, manufactureand erection of precast and tilt-up concreteelements can be found in the referenceddocuments.

This Industry Standard is based on currentknowledge and construction methodswithin the industry and is not intended toexclude other methods or processes thatcan be shown to meet the requirements ofproviding a safe workplace.

The August 2000 draft of this Standardwas prepared by a committee comprisingrepresentatives from the building industry,industrial unions and WorkCover.

The committee comprised:

Chair Pat PrestonConstruction, Forestry,Mining & Energy Union

Convenor Barry CrispCrisp Consultants Pty Ltd

Committee Allan EvansAustralian Precast Pty Ltd

Scott MatthewsCement & ConcreteAssociation

Hugh MorrisConmor Cranes Pty Ltd

Jim StoneConstruction, Forestry,Mining & Energy Union

Colin StylesVictorian WorkCoverAuthority

Introduction cont.

Consultation with the Victorian WorkCoverAuthority ensured overall compatibilitywith WorkCover legislation and technicalalignment with the revision of AS 3850,Tilt-up Concrete Construction.

The Foundations for Safety full committeeendorsed this document as an IndustryStandard in December 2000. Foundationsfor Safety is a forum comprisingrepresentatives of Victoria’s keyconstruction industry stakeholderorganisations.

The Victorian WorkCover Authoritypublishes this Industry Standard on behalfof Foundations for Safety.

It supersedes WorkCover’s 1987 Code ofPractice for Tilt-up Construction, whichhas now been revoked.

Part 1:General

1

1.1 Purpose

This Industry Standard provides practicalguidance for the design, manufacture,transportation and erection of precast andtilt-up concrete elements to ensure, as faras is practicable, a safe workingenvironment for those in the industry.

1.2 Scope

This Industry Standard providesrecommendations to assist in the safeconstruction of:

• precast concrete elements made off sitefor use in the building and constructionindustry

• tilt-up concrete elements, whether caston or off site, for use in the building andconstruction industry

• reuse of precast and tilt-up concreteelements already erected within abuilding structure

1.3 Special provisions

Some types of precast elements requirespecific manufacturing and erectionprocesses. These are dealt with in parts 5and 9. The use of such elements ispermitted, provided they comply with thegeneral intent of this Industry Standard.

1.4 Exclusions

This Industry Standard does not cover civilengineering elements such as bridgebeams and culverts or small concreteelements such as pavers, kerbs, drainpipes and pits, house stumps or otherelements weighing less than 400 kg.

1.5 Relationship to AustralianStandards

Precast and tilt-up concrete elementsshould be designed and constructed inaccordance with the Building Code ofAustralia and the relevant AustralianStandards.

This Industry Standard is intended tocomplement the key Australian Standardsdealing with precast and tilt-up concreteconstruction, AS 3600 and AS 3850.

Where any technical conflict arisesbetween a provision of either of theseAustralian Standards and a provision ofthis Industry Standard, the technicalprovision of the Australian Standard (asamended and reissued from time to time)must prevail.

Part 1: General cont.

2

1.6 Referenced documents andfurther reading

Documents referenced in this IndustryStandard are listed in appendix A. Thisappendix also provides a list of suggesteddocuments for further reading.

1.7 Definitions

The definitions of terms used in thisIndustry Standard are given in appendix B.

1.8 Pre-planning andcoordination

Pre-planning and coordination betweenthe relevant parties is essential tomaximise the benefits of precast and tilt-up methods of construction.

It is the responsibility of the project designengineer to ensure that the building isdesigned and detailed so that it can beconstructed as intended.

Prior to manufacturing the concreteelements, the builder, in association withthe precaster and the erector, should haveplanned the complete construction anderection sequences.

Close collaboration between the projectdesign engineer, the builder, the precasterand the erector is necessary to ensuresafety in construction.

Part 2:Training and hazard management

3

2.1 General

A principal objective of Victoria’sOccupational Health and Safety Act 1985 isto provide a safe working environment andto prevent harm to employees at work. Todo this, it imposes duties of care onemployers, employees, and others, andrequires employers and employees tocooperate in ensuring that workplaces andwork practices are safe and without risksto health.

One of the employer’s primary obligationsunder the Act is to provide:“such information, instruction, trainingand supervision to employees as arenecessary to enable the employees toperform their work in a manner that is safeand without risks to health.” [section 21 (2) (e)]

Employers owe this same duty of care toindependent contractors and theiremployees working at the workplace.

In fulfilling this obligation, the precastconcrete industry should maintain astructured system of education andtraining to enable both employers andemployees to:

• identify and manage the risks involved inthe manufacture, transportation anderection of precast concrete and tilt-upconcrete elements

• keep abreast of the current state ofknowledge within the industry on themeans of eliminating hazards andcontrolling risks to health and safety.

2.2 Training

Employees need to work safely. They mustbe trained and instructed in safe systemsof work and safe work practices.

Employers must ensure an appropriatelyexperienced person maintains closesupervision of employees who are not yetsufficiently skilled and experienced tocarry out their work safely.

Training programs should emphasiseoccupational health and safety and shouldprovide opportunities for individuals tohave their existing skills recognised and todevelop new knowledge and skills.Education and training programs shouldbe structured to lead to nationallyrecognised qualifications and should bedelivered by a registered trainingorganisation. Such training should be inaddition to and not replace therequirement for site-specific induction.

Part 2: Training and hazard management cont.

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Training and instruction programs shouldinclude:

• induction on this Industry Standard

• occupational health and safety (OHS)training to the industry competencystandard as defined by the NationalBuilding and Construction IndustryTraining Board, Construction TrainingAustralia

• first aid training to the minimumrequirements of WorkCover’s Code ofPractice for First Aid in the Workplace

• supervised practical experienceprograms specific to the tasks beingperformed by the employee. Suchtraining should be complementary to, orpart of, a program leading to a nationalqualification

• identification of hazards associated withthe use of plant and equipment

• the selection, care and use of protectiveclothing and equipment

2.3 Health and safety

Employers should ensure that allemployees have the opportunity to be fullyinvolved in the development of proceduresincluding hazard identification,assessment of risk and control of riskmethodology.

Employers have a general duty to ensurethe health and safety of employees while atwork. In particular they must take allpracticable steps to:

• provide and maintain a safe workingenvironment

• provide and maintain facilities for thesafety, health and welfare of employees

• ensure that machinery and equipment isdesigned, made, set up, and maintainedto be safe for employees

• ensure that employees are protectedfrom hazards in the course of their work

• provide procedures to deal withemergencies that may arise whileemployees are at work

Before commencing work on a project,employees must be informed by theiremployer of:

• emergency procedures

• hazards they may be exposed to while atwork

• hazards they may create while at workthat could harm other people

• how to minimise the likelihood ofhazards becoming a source of harm tothemselves and others

• the location and correct use of safetyequipment


5

Employers must inform employees of theresults of any health and safetymonitoring.

Employers are also responsible for thehealth and safety of people who are notemployees. Employers must take allpracticable steps to ensure that employeesdo not harm any other person while atwork, including members of the public orvisitors to the workplace.

Employees are responsible for their ownsafety and health while at work and mustalso ensure that their actions do not harmor place others at risk. They mustcooperate with their employer on healthand safety matters and must not interferewith or misuse anything provided by theiremployer to protect health and safety.

2.4 Hazard management

Employers must have in place an effectivemethod to identify hazards and todetermine whether there are significanthazards that require further action. Ahazard is an existing, new or potentialsituation or event that could jeopardise thesafe and healthy working environment.

In the precast and tilt-up concreteindustry, risk is always present whenhandling, transporting and erectingelements. Under no circumstances

should personnel stand below or work onan element that is leaning towards them.

Although component failure is rare theconsequences are always significant.

To ensure appropriate hazardmanagement, an assessment of the risksmust be carried out by the builder inconjunction with the health and safetyrepresentatives of the contractors andworkers involved in the work.

A job safety analysis that lists the hazardsand suggests safety procedures shouldalso be prepared. The minimumrequirements for this job safety analysisinclude:

• an identification of the hazards

• an assessment of the risks from thehazards identified

• control measures required to eliminateor minimise the risks from the hazards

• identification of the person responsiblefor implementing and monitoring thecontrol measures

Where possible, the hazard should beeliminated or the risk reduced by changingor modifying the proposed work method,construction method, or by use ofalternative equipment.


6

Where the hazard cannot be eliminated,control measures must be implemented toisolate the hazard and to minimise risk toemployees. In these circumstances,measures such as barricading areas ofdanger, provision of specific safety trainingand work instructions, use of protectiveequipment, and posting of warning signsshould be implemented. Such measuresshould be discussed with employees andevaluated to ensure that they are effectiveand do not create additional hazards.

The accepted means of planning toprevent injury is to identify, assess andthen control the risk. At the control stagethere is a recognised hierarchy of hazardcontrol measures that should be applied.These processes for managing risk areincluded in various occupational healthand safety (OHS) regulations, and shouldbe followed as part of the hazardmanagement process.

2.5 Incident notification

Under OHS regulations, WorkCover mustbe immediately notified in the event of aworkplace fatality, an injury requiringmedical treatment, or a dangerousoccurrence. This includes the failure of aload during lifting, the collapse of a craneor the collapse of a panel or any other partof a building.

Further information is given in theWorkCover booklet, WorkCover IncidentNotification.

Part 3:General design provisions

7

3.1 General

In precast concrete construction, there aretwo separate phases of design.

The first, the structural design, is for thein-service condition and is usually carriedout by the project design engineer as partof the design of the complete structure.

The second, the design for erection, is forthe handling, transportation and erectionof the individual elements and structureduring the erection process. It may becarried out independently of the structuraldesign by the project design engineer orby the erection design engineer.

The structural design should be carried outby a designer experienced in the field ofprecast concrete construction and who is aregistered building practitioner inaccordance with the requirements of theBuilding Act 1993.

The structural design should take intoaccount the particular requirements ofprecast concrete structures to ensure thatthe elements can be erected.

3.2 Building stability

The stability of the whole building shouldbe checked by the project design engineeror the erection design engineer at eachstage during erection and under in-serviceload conditions.

Special care should be taken in design andduring construction to guard againstprogressive collapse.

Progressive collapse means a continuoussequence of failures initiated by the localfailure of one part of the structure. Precastconcrete structures are susceptible to thistype of failure.

Progressive collapse may be prevented byproviding either:

• adequate structural strength andcontinuity of the structure and its parts

• alternative load paths that cause appliedforces to be safely transmitted throughthe structure

The failure of a single member should notlead to the complete collapse of thestructure. This is particularly importantwhere structural stability is provided bysteel roof-bracing systems.

3.3 Specification of concrete

The concrete specification should beclearly shown on the drawings and includeany special requirements, for example,colour, cement content and water-cementratio.

Part 3: General design provisions cont.

8

The specification of the strength ofconcrete should take into account thestrength required at lifting as well as therequirements for in-service loading,durability and ease of construction. Someguidance on the early-age strength ofnormal-class concrete is given in AS 1379.

The concrete strength required at liftingshould be in accordance with the liftinginsert manufacturer’s specifications. Toobtain adequate concrete strength for earlylifting, it may be necessary to specify28-day concrete strengths of 32 MPa orhigher.

Advice on the specification of concrete forbrace footings is given in section 4.13.

3.4 Structural design

The structural design of the concreteelements should be carried out inaccordance with the requirements ofAS 3850 and AS 3600, as appropriate, andthe provisions of this Industry Standard.

Slenderness and stability are majorconsiderations in the design of precast andtilt-up concrete elements. Precast concreteconstruction may lack the continuityinherent in cast insitu concrete structures.The designer should address these issues.

Structural members supporting precast ortilt-up elements should be designed toallow for the situation where the elementmay bear on only two discrete pointsduring erection.

Detailed information on the design oflightly loaded wall panels is available inRecommended Practice, Design of Tilt-upConcrete Wall Panels, published by theConcrete Institute of Australia and in thereferences given in appendix A.

3.5 Loads

Precast and tilt-up concrete elementsshould be designed for the loads andconditions likely to be experienced duringthe manufacturing, lifting, transportation,erection, braced and in-service phases.

In addition to the normal designconsiderations, special considerationshould be given to:

• construction loads

• handling and transport loads

• erection loads

• wind load on the braced elements priorto incorporation into the structure

• seismic (earthquake) loads


9

Erection-load design should considervariations to the precast element load-distribution during lifting, rotation andimpact during placement.

3.6 Element size andreinforcement

In determining the size and shape ofprecast and tilt-up concrete elements,consideration should be given to factorsincluding:

• whether elements are to be cast on siteor off site

• size, capacity and configuration ofcrane(s) available to undertake erection

• access to and around the site

• bracing and propping requirements

• transport restrictions

Where precast elements are to be cast offsite, consideration should be given tolimiting one dimension so that the elementcan be transported by conventional meanswithout the need for a pilot or specialpermit.

For concrete wall panels, the thicknessshould be determined by limiting theextreme fibre tensile stresses so that thesection remains “uncracked”. Appropriatereinforcement should then be determinedby using a cracked-section analysis.

Extra reinforcement may be required atopenings and at temporary support pointsto control cracking in precast and tilt-upconcrete elements.

In determining reinforcement for precastconcrete elements, consideration shouldbe given to the possibility of load reversaldue to mishandling during transport orerection. This is particularly relevant toprestressed concrete elements.

3.7 Joints

Joint widths (gaps) between adjacentprecast and tilt-up concrete elementsshould be sufficient to maintain designedposition and alignment during erection andaccommodate tolerances and expectedmovements.

Unless otherwise specified, joint widthsbetween adjacent elements should not beless than:

• 15 mm for joints with flexible sealant

• 20 mm for mortar or grouted joints

• 150 mm for insitu concrete infills

When selecting joint filling materials,consideration should be given to:

• thermal and shrinkage movement of theelement

• fire resistance level


10

• weather resistance

• structural movements to beaccommodated

3.8 Composite construction

Composite concrete elements formed byadding insitu concrete to a precastconcrete or steel section should bedesigned by the project design engineer toaccommodate the progressive loading andstrength at each stage of the construction.

Loading cases can include uneven loadingof the precast element during erection andwhile pouring the insitu concrete.

Where the design of the compositeelement is based on a specific erection andinsitu pouring sequence, this should beclearly specified on the drawings.

Where steel beams are used to supportprecast concrete elements, care should betaken in assessing the stability of the beamduring construction. Friction forcesbetween steel and concrete should not beconsidered as providing stability to thebeam.

Where specific roughness is required onthe surface of the precast element toprovide a key for the insitu concrete, thisshould be clearly specified on thedrawings.

Where temporary propping is requiredduring erection or for supporting the insituconcrete, these requirements should beclearly shown on the drawings. Thisshould include prop capacities andconfigurations, taking into account thepouring sequence for the insitu concrete.

3.9 Connections

Connections between precast or tilt-upconcrete elements, or connections to otherstructural members, must be designed toresist the forces imposed on theconnections in accordance with therequirements of AS 3600 and AS 3850, asappropriate.

The design of the connections must takeinto account the capacity of both the fixingand the concrete.

Fixings must be designed to fail in a ductilemanner.

For cast-in fixings or undercut drilled-inanchors, the ultimate capacity should bethe lesser of fixing failure in tension and/orshear, or concrete cone failure.

For all drilled-in expansion anchors theultimate capacity should be determined inaccordance with AS 3850.


11

Deformation controlled expansionanchors, drop-in anchors, spring-set boltsand self-drilling anchors are unreliable andmust not be used in lifting or bracingconnections.

Impact driven fixings including explosivecharge driven fixings are not appropriateas fixings in structural connectionsbetween precast or tilt-up elements andmust not be used.

Further information is given inWorkCover’s Guidance Note, Use ofAnchors as Bracing Inserts in PrecastConcrete Panels.

Where possible, cast-in fixings such asfully anchored threaded inserts, weldplates or brackets should be used.

Threaded inserts, cast-in weld plates andbrackets must be fully anchored to transferthe loads into the concrete. Anchorage andload transfer is achieved for threadedinserts by an enlarged “foot” on theembedded end or by the use of a crossbarfitted through a cross-hole (see figure3.1). Note that connections must bedesigned to fail in a ductile manner andthat this may require fixings to haveanchor bars of sufficient length to developtheir full capacity.

Desig

n de

pth

for c

one f

ailur

e

May have enlargedbase in lieu ofanchor bars

Anchor bar minimum12mm dia x 350mm long

Corrosion resistantcross-holed ferrule,20mm minimum diameter

Fig 3.1: Threaded inserts


12

Weld plates and brackets must beanchored with anchor bars of a diameterand embedment depth capable of inducinga full shear cone.

In shallow embedments, where theconcrete strength is insufficient to developthe required design load, considerationshould be given to increasing anchorageby using fully developed reinforcing bar(s)of sufficient capacity to anchor the fixing.

Fixing capacities are reduced when fixingsare placed in near proximity to each otheror near edges and openings. Dueconsideration must be given to the effectsof interference with other fixtures, fittings,reinforcing and proximity of openings andedges. In these cases, considerationshould be given to providing additionalreinforcement or other means to preventfailure.

Where fixings are to be exposed to theweather after construction, they should bemanufactured from corrosion-resistantmaterials or protected by suitable coatingsystems.

3.10 Lateral restraint

All precast concrete and tilt-up concreteelements should be incorporated into thestructure in such a manner that the risk ofprogressive collapse is minimised.

In assessing the requirements forconnections between elements,consideration should be given to theeffects of abnormal loads on the building,such as gas explosions or vehicle impacts.For detailed information andrecommendations on these issues, refer tothe Planning and Design Handbook onPrecast Building Structures listed inappendix A.

Positive connections between elementsand other parts of the structure should bespecified and detailed. Such connectionsmust be designed to resist imposed lateraland vertical forces and should ensure thatbrittle failure cannot occur. See alsosection 4.11.

Frictional forces cannot be consideredsufficient to provide horizontal restraintbetween elements.


13

3.11 Tolerances

Recommended tolerances are given in part5 and should be taken into consideration inthe design.

Because precast and tilt-up concreteelements cannot be manufactured to exactdimensions, provision should be made inthe design for dimensional variation.

Where required tolerances are less thanthe recommended values given in part 5,the specific requirements should be clearlystated on the drawings.

Bottom ofwall panel

Grout tube

Reinforcement cutaround grout tubeas necessary

Additional reinforcementeach side of grout tube

Fig 3.2: Grout tube

Grout tubes, particularly in the edges ofthin panels, should be provided withrestraining reinforcement on each side ofthe tube (see figure 3.2).


14

3.12 Structural drawings

Drawings and details must providesufficient information for the shop detailerto prepare detailed shop drawings.

The information provided on structuraldrawings should include:

• date and issue number of the drawing

• plans and elevations clearly indicatingthe structural framing and precastelement layout

• structurally critical dimensions

• reinforcement required for in-serviceloads and conditions

• framing connection locations andrequired type (e.g. cast-in) and thecapacity of the fixing inserts

• levelling pad details

• structural design criteria affectingconstruction

• the concrete specification including allspecial requirements to meet in-serviceloadings and conditions and a note thatall concrete must meet the strengthrequirements at the time of liftingnominated on the shop detail drawings

• base connection details, for example,grouting sequence of dowel connections

3.13 Shop drawings

The project design engineer should ensurethat the shop drawings comply with thestructural design. The builder shouldcheck the shop drawings for compliancewith dimensions. The shop drawingsshould include all the information outlinedin part 4.

3.14 Casting and erectionsequences

The casting and erection sequences of theprecast and tilt-up concrete elementsshould be agreed as outlined in part 4.

Part 4:Design for erection

15

4.1 General

This section provides specifications for thedesign of the precast elements to ensurethat they resist the forces to which theywill be subjected during handling,transportation and erection.

Shop drawings should be prepared foreach element and should incorporate all ofthe details and requirements for thehandling, transportation and erectionrequirements.

Shop drawings are normally theresponsibility of the precaster.

As part of the structural design process,the project design engineer must providesufficient details to allow the shop detailerto prepare shop drawings and the erectiondesign engineer to prepare the erectiondesign.

The shop drawings and erection designshould be submitted to the project designengineer for review to ensure that theycomply with the requirements of thestructural design.

4.2 Planning

Prior to preparation of the shop drawings,the parties involved in the design,manufacture, transport and erectionprocess should liaise to plan the completeconstruction and erection sequences.Consideration should be given to detailssuch as site limitations, local streetaccess, delivery sequence, transportrequirements, and overhead obstructions.These aspects can have a significant effecton the size of precast elements and on theerection process.

4.3 Shop drawings

Where possible, the orientation of theelements on the shop drawings should bethe same as the proposed castingorientation, i.e. the shop drawing shouldview the element as set out on the castingbed.

Shop drawings must include the following:

• date and issue number of the drawing

• project location

• element number

• the mass of each element

Part 4: Design for erection cont.

16

• element dimensions and centre ofgravity

• structural reinforcement

• the location, orientation and depth of allinserts and the configuration and coverof any component reinforcement that isrequired*

• where applicable, the type, make,capacity and technical specifications of:

– element braces

– lifting inserts

– bracing inserts and fixings

– fixing inserts and, if required,

– strongbacks, strongback fixing insertsand locations

• the size, configuration and cover of anyadditional reinforcement required for thetransport and lifting of the element

• levelling pad details

• the class and strength grade designationof the concrete as defined in AS 3600

• the required concrete compressivestrength of the element and bracingfootings as applicable at the time oflifting and erecting**

• the surface finish of each element

• where appropriate, the tolerance limitson the element

• the orientation of the elements

• rigging details

In addition, the shop drawings mustinclude a layout drawing (marking plan)showing the following:

• location of each element

• where applicable, rigging diagramsdetailing the required configurationswith sling lengths, spreader/lifting beamrequirements and arrangement ofsheaves

• configuration of erection braces, andwhere applicable, knee braces and lateralrestraints

• required capacities of erection braces

• requirements for erection bracefootings, brace fixings and concretestrength of footing at time of erection

The shop drawings should be signed anddated.

Notes: *All edge lift inserts and someother inserts require componentreinforcement and details should beobtained from the suppliers of these items.

**Concrete strength grades higher thanthat specified on the structural drawingsmay be necessary to achieve the concretestrengths required at the time of lifting.


17

4.4 Loading

As well as the in-service design, precastand tilt-up concrete elements must bedesigned for the loads and conditionslikely to be experienced during themanufacturing, lifting, transportation anderection phases.

Special consideration should be given tothe following:


• handling and transport loads

• erection loads

• wind load on the braced elements

Erection-load design should considervariations to the precast element load-distribution during lifting, rotation andimpact during placement.

The effect of suction and adhesion atseparation from the form or casting bed(lift-off) and dynamic and impact loadingduring transportation, erection andbracing should be considered.

Suction loads may vary according to thefinish of the panel and the type of form orcasting bed. Recommended minimumvalues are:

• for concrete cast onto a steel bed, a 20%increase should be applied to the deadload

• when casting concrete onto concretecasting beds, a 40% increase should beapplied to the dead load

• where the casting bed has a profiled ortextured surface the “suction” load mayexceed 100% of the dead load.Consideration should be given to thecasting bed profile to ensure thatadequate draw (slope) is provided to thefixed edges of the form not struck priorto lifting. A minimum draw of 1:12 isrecommended

Impact loads generated during handlingand transport can be significant andshould be considered in the design of thelifting inserts and rigging system. Theseincreases may range from 20% duringhandling by crane to up to 100% duringtransportation.

Impact loading should only be consideredafter release (lift-off) of the element fromthe casting bed. The increase in designloads due to suction and impact are notcumulative.


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4.5 Composite construction

The structural design of compositeconcrete elements formed by adding insituconcrete to a precast concrete or steelsection must take into account theprogressive loading and strength of theelement at each stage of the construction.

The design for erection of such elementsalso requires the progressive loading andstrength of the structure to be assessed ateach stage of construction. This can be acomplex process and may require detailedanalysis and design. Such analysis anddesign must comply with the requirementsof section 4.14.

The following are some of the issues thatshould be addressed here:

• where the design of the compositeelement is based on a specific erectionand insitu pouring sequence, this shouldbe clearly specified on the shopdrawings

• where specific roughness is required onthe surface of the precast concreteelements to provide a key for the insituconcrete, this should be clearly specifiedon the drawings

• where steel beams are used to supportprecast concrete elements, care shouldbe taken to ensure the stability of thebeam during construction. Frictionforces between steel and concreteshould not be considered as providingstability to the beam

• the requirements for temporarypropping during erection or forsupporting the insitu concrete should beclearly specified on the shop drawings.These requirements should include propcapacities and configurations. Thepouring sequence for the insitu concreteshould be clearly specified on the shopdrawings

4.6 Additional reinforcement

Additional reinforcement may be requiredin the precast elements to accommodateforces during handling, transportation anderection.

For elements that are intended asuncracked sections, additionalreinforcement or strongbacks should beprovided where the maximum flexuraltensile stress in the element exceeds thelimits recommended in AS 3850.


19

For wall panels:

• additional reinforcement may berequired along the bottom of the panel toresist stresses arising from thermal andshrinkage movements while the panel issupported only on the levelling pads

• additional reinforcement may berequired at edges and around openingsto resist thermal and shrinkage stressesand to prevent cracking due to panelmishandling

Additional reinforcement may be requiredin prestressed concrete elements wherethere is a possibility of load reversal duringtransport or erection.

4.7 Design for lifting

The number of lifting inserts requireddepends on several factors including theelement size and shape, insert capacityand insert location. The location of liftinginserts is interrelated with thereinforcement design and the proposederection procedures.

When locating lifting inserts, considerationshould be given to the need forstrongbacks if the precast element haslarge or awkwardly located openings.


20

Multiples of three rows or columns oflifting points where equal loading isrequired should be avoided because of thecomplex rigging configurations required.

For example, the lifting of systemscomprising 3, 6, 9 or 12 lifting pointsshould be avoided. Preferred lifting insertconfigurations for tilt-up wall panels areshown in figure 4.1.

MinimumC + 300mm

Minimum 2D

2 x 1

C

D

2 x 2

Minimum 4.5D or 4.5Ewhichever is the greater

Minimum 2D

Minimum 3D

E

D

2 x 44 x 2

Minimum3C + D

8

C

D

4 x 1

Edge lift

D

Note that dimensions on slings are total length through sheaves

*The lifting insert supplier may specify a maximum value for this angle

*

Fig 4.1: Wall panel rigging


21

In general, the rigging system should bedesigned to distribute equal loads to alllifting points. In some circumstances thedesign may require unequal loading onlifting points. Where this is the case, suchrequirements should be clearly specified inthe shop drawings.

Where fixed length multi-legged slings areto be used to lift an element, the liftinginserts must be designed to carry the fullmass of the element on any two liftinginserts.

To prevent the element slewing sidewaysduring erection, lifting inserts should belocated symmetrically about the centre ofgravity across the width of the element. Indetermining the centre of gravity, the effectof any additional equipment, such asstrongbacks, needs to be taken intoaccount. When the element is lifted, thebottom edge should be horizontal.

Lifting inserts may be positioned in theface or edges of a precast or tilt-upconcrete element. The actual locations ofthe lifting inserts are determined accordingto the:

• method of lifting (face or edge)

• mass of the element

• size of the element

• shape of the element and presence ofopenings and cut-outs

• structural capacity of the element

• concrete strength at the time of lifting

• capacity of the lifting inserts, includingedge effects and embedment depth

When it is intended that wall panels betilted about an edge using anchors placedin the panel face, the geometric centre ofthe face-lift inserts must be above thepanel’s centre of gravity.

Face-lifted panels should be designed tohang no more than approximately 10degrees from the vertical. If this is notpossible, consideration should be given tousing edge-lifting or a combination offace-lifting and edge-lifting.

For multi-storey construction, precastwalls elevated above the ground must beedge-lifted unless there is a workingplatform on each side of the final locationof the element.


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4.8 Lifting inserts

Proprietary cast-in lifting inserts should bespecified. The inserts should have testcertificates available, issued by a NATA oran equivalent testing authority.

Lifting inserts must comply with therequirements of AS 3850.

Lifting inserts should be positioned toensure that after casting, the followinginformation is still visible:

• the insert manufacturer’s symbol orname

• the lifting capacity of the insert

• the insert length

Lifting inserts must be designed,manufactured and installed to provide aworking load limit (WLL) with a designfactor of at least 2.5 against concretefailure. In determining this, the appliedload should include the mass of theelement as well as suction and impact loaddue to lifting.

Lifting inserts should be installed inaccordance with the manufacturer’sinstructions. Particular care must beexercised when inserts require tying toreinforcement, or where componentreinforcement or special reinforcingelements are required for the properinstallation of lifting inserts.

The load capacity of the inserts dependson several factors (see figure 4.2),including:

• the concrete strength of the element atthe time of lifting

• embedment depth of the insert

• direction of load, shear or tension

When selecting a lifting insert, ensure thatthe nominated capacity from themanufacturer’s catalogue is for thedirection of the load being applied.

All lifting inserts require adequateembedment or anchorage to functioneffectively. Anchorage is affected by:

• proximity to edges

• proximity to holes, recesses or edgerebates

• proximity to other loaded lifting devices

• concrete thickness

• concrete strength at lifting

• embedment depth

• the presence of cracks

• the proximity of reinforcement orpre-stressing tendons

Horizontal bars placed around the foot ofa lifting insert may provide very littleadditional lifting capacity to the insert.


23

When fixed length multi-legged slings areto be used for lifting precast elements, anytwo of the lifting inserts must be capableof supporting the total load.

Where prestressing strand is used asa lifting loop, it must comply with therequirements of AS 1311.

Precast wall panelDirection of load before rotation

Edge lifter

Precast wall panel

Direction of load after rotation

SHEAR LOAD

Edge lifter

TENSION LOAD

Fig 4.2: Shear loads and tension loads in edge-lifted panels


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4.9 Strongbacks

Precast and tilt-up concrete elements thatare odd shaped, elongated or with large orawkwardly positioned openings mayrequire the addition of strongbacks toenable them to be successfully lifted andplaced. Strongbacks may be used tostrengthen the elements or to locateadditional lifting points to prevent out-of-plane rotations of odd-shaped elements.

Where strongbacks are used, their weightmust be included in the calculation todetermine the element’s centre of gravity.

Strongback fixing inserts should be eithercast-in or post-installed heavy dutystructural expansion anchors designed inaccordance with the requirements ofsection 4.12.

4.10 Slenderness effects

Buckling and instability can occur duringlifting and erection of long, slenderelements.

Lifting inserts should be located to ensurethat compression flange buckling (as in along slender beam) cannot occur,particularly during rotation of wall panels.

The span/thickness ratio of the elementbetween lifting points should be limitedto a maximum of 60 unless a detailedbuckling analysis is undertaken(see figure 4.3).

Rigging totailing hoist

Thickness

Recommended maximum

span/thickness: 60

Rigging tomain hoist

Precast wall panel

Fig 4.3: Panel rotation


25

4.11 Bracing and propping

Temporary bracing and propping systemsmust be designed to resist all expectedloads, including:


• wind loads for temporary structures inaccordance with AS 1170.2

Braces must have a permanently fixedidentification plate displaying the followinginformation:

• the supplier or manufacturer

• the model type or designation

In addition, the load capacity of the bracesmust be marked as follows:

• for fixed length braces, the WLL, inkilonewtons (kN), on the permanentidentification plate

• for adjustable length (telescopic) braces,the WLL, in kilonewtons (kN), atmaximum and minimum extension, onthe permanent identification plate

• for composite braces, the WLL, inkilonewtons (kN), at maximum andminimum extension, suitably and clearlymarked on the brace

The working load limit for braces atmaximum and minimum extension mustbe determined in accordance with therequirements of AS 3850, taking into

account the forces and eccentricitiesassociated with the complete assembly ofcomponents that comprise the brace.Where this involves testing, such testsshould be conducted by a registered NATAlaboratory or equivalent.

The working load limit for props must bedetermined in accordance with therequirements of AS 3610.

Brace and prop requirements and detailsfor each type of precast or tilt-up concreteelement must be clearly specified on theshop drawings. Where applicable, thisincludes requirements and details for kneebracing and lateral restraint bracing.

There should never be less than twotemporary supports to each element,unless specifically designed and detailedand approved by the erection designengineer. Such requirements and detailsmust be clearly shown on the layout andshop drawings.

Brace adjustment mechanisms must havestops on the threads to prevent over-extension and retaining devices to preventunintentional dislodgment of the lockingpin. The locking pin should be constructedso that it cannot be undone without theuse of a tool.


26

The bracing foot or shoes should bedesigned to prevent lateral displacement ofthe shoe from the fixing insert afterinstallation.

Two braces or props may not be necessarywhere precast or tilt-up concrete elementsare provided with erection brackets orpermanent connections to other restrainedelements such as steel portal columns orwalls forming a stable “box” structure.

Where single braces are used, they shouldbe clearly specified on the shop drawingsand have a minimum of two fixings at eachend.

Where single braces are used, particularcare is required on site to prevent anydamage that could be caused by impact orfailure of the brace or fixing insert.

A brace connected to one element mustnever be connected to another element forsupport, unless this is clearly specified onthe shop drawings.

The ideal location of bracing points in awall panel is at two-thirds of the height,measured from the base of the panel.Where it is necessary to locate bracingpoints below the element’s centre ofgravity, this should be specificallydesigned and detailed on the shopdrawings. Special provisions should be

made to prevent “kick-out” of the base ofthe element.

Where brace angles are outside the rangeof 45–60 degrees to the horizontal, designcomputations must be prepared to verifybrace, brace fixing and brace footingcapacities (see figure 4.4).

For face-lifted wall panels, bracing insertsshould be on the same face of the panel asthe lifting inserts. This is to ensure thatpersonnel are not required to fix a brace toa wall panel that is leaning towards them.

Props supporting precast concrete floorunits should have rigid saddles to supportthe top bearer. The top bearer should belocated in the saddle in such a way as toprevent rolling of the bearer and to ensurethat the load is transferred concentricallyinto the prop. Where bearers are lappedover a prop, the capacity of the prop mustbe sufficient to resist eccentricity due toloading on one side only.

Precast and tilt-up concrete elements mustremain braced or propped until they areadequately restrained or incorporated intothe final structure.

Braces must be maintained and inspectedbetween each use to ensure that allcomponents are correct and in goodworking order.


27

Pane

l hei

ght

typi

cally

2 /3 p

anel

hei

ght

20mm diameter threadedcast-in insert

Required capacity ofbrace to be nominatedon shop drawings

Type of fixing to benominated on shopdrawings

45-60°

Floor slab

Fig 4.4: Panel bracing

4.12 Bracing inserts

Bracing inserts provide the connectionbetween the brace and the braced elementor brace footing.

Bracing inserts must be designed to resistall expected loads, including:



Cast-in bracing inserts should be usedwhere possible. Where cast-in inserts are

not used, acceptable alternative insertsare:

• mechanical fixings, such as undercutanchors and drilled-through fixings,used in accordance with themanufacturer’s or supplier’srecommendations

• load-controlled (torque-controlled)expansion anchors with a permissibleload limited to 0.65 of the “first slipload”, established in accordance withAS 3850.

Chemical anchors relying solely onchemical adhesion must not be used forbracing inserts unless each insert is


28

individually proof tested to the workingload limit.

Deformation-controlled anchors, includingself-drilling anchors and drop-in (setting)impact anchors, must not be used.

Bracing insert capacities are sensitive to:

• the method of installation

• the strength of the concrete into whichthey are placed

• the distance from the insert to the edgeof the element

Unless expressly designed and clearlyspecified, no bracing insert should becloser than 300 mm to the edge of theelement or the bracing support.

Substitution of anchor or insert types andmanufacture must not be made withoutthe written approval of the shop detailer orthe erection design engineer.

Bracing insert requirements and details foreach type of precast or tilt-up concreteelement must be shown on the shopdrawings.

Bracing inserts should be located to allowthe braces to hang vertically withoutinterfering with the lifting rigging. Aminimum horizontal displacement of200 mm for the bracing insert from thevertical line of the lifting inserts willnormally be adequate.

When designing bracing inserts forfootings, the strength of the concrete inthe brace footing must be considered.Bracing footings are frequently cast only afew days prior to erecting the precastelements. Concrete strength required inthe brace footing at the time of erectionmust be clearly specified on the shopdrawings.

Further information is given inWorkCover’s Guidance Note, Use ofAnchors as Bracing Inserts in PrecastConcrete Panels.

4.13 Brace footings

Brace footings should be designed toresist all expected loads, including:



Brace footing requirements and details foreach type of precast or tilt-up concreteelement must be clearly specified on theshop drawings. This must include therequired concrete strength at the time ofinstallation of the bracing.

Unless specifically designated otherwise,the concrete strength of the brace footingat the time of installation of the bracingmust be at least 20 MPa.

Written confirmation of the requiredconcrete strength of the brace footing


29

must be provided to the erector by thebuilder before erection commences.

In calculating the capacity of the bracefooting, the direction of the applied braceloads, both in compression and in tension,must be taken into account. Combinedvertical and sliding mode failure must alsobe taken into account. The design of thebrace footing should be in accordance withthe relevant Australian Standards.

The likely concrete strength at the time oferection should be considered in thedesign of the brace footing.

The ends of braces must be fixed to asolid, flat concrete or other surface that iscapable of resisting the applied loads.

4.14 Special provisions

This section sets out additionalrequirements that apply in the case ofbuildings, or portions of buildings:

• greater than one panel in height

• incorporating wall panels greater than8 m in height

• incorporating wall panels weighing morethan 8 t

• incorporating wall panels which are notnominally flat or rectangular

• where wall panels are not directly fixedand supported by a free-standingstructural frame

A work method statement should beprepared by the precaster and erector inconjunction with the builder and inconsultation with the workers’ health andsafety representative(s).

The work method statement should bespecific to the project and be approved inwriting by the builder and the site safetyofficer. The work method statement shouldinclude the following:

• a general description of the erectionprocess, identifying the objectives of theerection process and broadly describinghow these objectives are to be realised

• a statement identifying who will beresponsible on site for each phase of theerection process

• a risk analysis to identify criticalactivities involved in the erection and aclear statement describing how the risksin each activity are to be eliminated orminimised

• design computations prepared by aregistered building practitioner who is asuitably qualified and experiencedengineer.

These computations should be based onthe requirements of the relevantAustralian Standards and shouldconfirm the stability of the structure


30

during the erection process and include,but not be limited to;

– temporary brace and bracing insertcapacities. Under these specialprovisions the braces should havea minimum capacity in tension orcompression of 10 kN;

– propping or falsework requirements

– brace or prop footing sizes

– temporary fixings required to providestability during erection

– lifting insert and rigging system

Design requirements should be reviewedby the project design engineer to ensurethat they comply with the requirementsfor the completed structure

• a component casting schedule

For tilt-up components this scheduleshould be derived from the erectionsequence and should be a plan showingthe casting location for each componentin relation to its final erected position

• an erection schedule

This should detail the erection sequenceand identify the crane location for eachlift, crane capacity and equipmentrequired and minimum numbers ofpersonnel required.

It should show:

– temporary brace and bracing insertdetails

– propping or falsework requirements

– brace or prop footing sizes andconcrete strength required at the timeof erection

– temporary fixings required to providestability during erection

– required concrete strength ofelements at the time of erection and

– lifting insert and rigging systemdetails

4.15 Erection design engineer’scertificate of compliance

The erection design engineer must providethe builder with a statement that thedesign of the elements is in accordancewith the relevant Australian Standard andwith this Industry Standard.

The statement should be in the form of theerection design engineer’s certificate ofcompliance shown in appendix C.

Part 5:Manufacture

31

5.1 Pre-planning

Prior to manufacturing the precastelements, the parties involved in thedesign, manufacture transport anderection process should liaise and haveplanned the complete construction anderection sequences. Factors that need tobe taken into account in this processinclude:

• site limitations and local street access

• panel size

• crane size, configuration, mobility andaccess

• delivery sequence

• transport requirements

• overhead obstructions, especially tramor train wires, overhead power lines andconstruction site overhead power

5.2 Shop drawings

The precaster should provide detailedshop drawings of each precast or tilt-upconcrete element in accordance with therequirements of part 4.

These shop drawings should be approvedby the builder and reviewed by the buildingdesigner and project design engineer priorto commencing manufacture of theelements.

5.3 Casting and erectionsequences

The casting and erection sequences of theprecast or tilt-up concrete elements shouldbe agreed between the builder, precaster,erector and, where necessary, the erectiondesign engineer and/or project designengineer. The precaster, in association withthe builder and erector, should prepareplans showing the erection sequence andbracing layout in accordance with therequirements of part 4.

The casting and erection sequencesshould take into account the requiredcrane capacity and configuration.

When assessing crane requirements, notethat:

• a crane’s rated capacity refers to itscapacity at a minimum radius and oftenbears little relation to its actual capacityto lift large panels

• the selection of crane size must be madewith consideration to the working radiusand boom extension required

Part 5: Manufacture cont.

32

• for face-lifted wall panels, assessment ofthe true working radius of the craneshould be made by adding at least 1.5 mto the final panel position radius. Thismay need to be increased for tall panels(see figure 5.1)

For tilt-up panels, the casting sequenceshould reflect the erection sequence.

To avoid multiple handling with stack-casttilt-up panels, the top panel should beerected first.

Rotation

Note: the increase in radiusmay be 1.5m or greater.

Radius of placed finished panel

True working radius while placing panel

Clearance required for obstructions

Fig 5.1: Crane lifting radius


33

5.4 Formwork

Formwork must be in designed andconstructed in accordance with AS 3610.

Precast and tilt-up concrete constructionusually requires multiple use and earlystripping of formwork and theserequirements should be taken into accountin the design of the formwork.

Formwork or mould design for precast ortilt-up concrete elements can have a directbearing on how elements are cast andhandled and on the loads imposed duringmanufacture. In particular, the followingshould be noted:

• surface finish requirements caninfluence the preferred orientation of aprecast element in the mould. Thequality of the finish of vertical mouldfaces may differ from that cast against ahorizontal surface. Two-stage castingcan be used to avoid this problem

• moulds for elements such as beams andcolumns may require special provisionsto accommodate prestressing.Generally, the side forms should bereleased or removed prior to releasingstressing strands. Stop ends should bedetailed to accommodate sliding of thecomponent during release

• both suction and friction can be reducedby the use of high quality mould releasecompounds

• suction on flat mould surfaces isincreased by the presence of water.Suction pressure can be relieved bylifting gently at one end or edge of theelement

• friction forces are increased by verticalor near vertical sides on a mould. Toreduce friction, mould sides should bedetailed with adequate draw, or shouldbe released to allow them to spring back.To avoid overloading lifting inserts, themould can be vibrated while gently liftingone end of the precast element

Manufacturers of prestressed elementsshould be aware of the inherent hazardsand risks of the stressing operation andshould have adequate control measures inplace to safeguard workers from all suchrisks.

5.5 Tolerances

Unless otherwise specified, tolerancesshould be in accordance with theappropriate Australian Standards.

For tilt-up panels, the appropriateStandard is AS 3850.

For other precast concrete elements, theappropriate Standard is AS 3610.


34

The tolerance on deviation from planenessof the casting bed should be such that theas-cast element meets the aboverequirements.

The effects of cumulative tolerancesshould be considered. It is recommendedthat the total accumulation of tolerance beno greater than 20 mm. Where morestringent tolerances are required, theseshould be clearly specified on thedrawings by the project design engineer.

The visual impact of element misalignmentmay be reduced by the use of variousdetails such as chamfers and arrises.

5.6 Reinforcement

Reinforcement should comply with therequirements of the appropriate AustralianStandards.

Reinforcement should be securely fixed inaccordance with AS 3600 and supportedin the correct position to preventdisplacement during concrete placement.

Where plastic-tipped metal bar chairs areused to support reinforcement in externalwall panels, care should be taken to ensurethat the plastic tips are not damagedduring or after manufacture.

5.7 Lifting inserts

Inserts should be cast-in proprietaryproducts that comply with therequirements of part 4. They must be ofthe type and capacity specified on the shopdrawings.

Factors affecting the load capacity of theinserts include:

• the concrete strength of the element atthe time of lifting

• embedment lengths of the insert

• direction of loading; shear or tension.

See figure 4.2 for further details.

No variations should be made to thespecified lifting insert locations on theapproved shop drawings without thewritten approval of the shop detailer. Ifchanges are made, the shop drawingsshould be amended accordingly.

Inserts must be accurately positioned andsecurely tied in accordance with thesupplier’s recommendations and asdetailed on the shop drawings. Insertsmust not be welded without prior approvalof the shop detailer or the erection designengineer.

Where different types of inserts are usedon a single project, particular care must betaken to ensure that all components arecompatible.


35

5.8 Strongbacks

Precast or tilt-up concrete elements thatare odd shaped, elongated or with largeawkwardly located openings may requirestrengthening for lifting and erection bythe addition of strongbacks.

The shop detailer or the erection designengineer should approve any changes tothe specified strongback system. The shopdrawings should be amended accordingly.

5.9 Concrete placement

Prior to placing concrete, the arrangementmust be inspected for compliance with theshop drawings. In particular, this mustinclude checks on:

• formwork dimensions

• formwork stability

• edge details and penetrations

• connection details

• insert locations, types and fixing toreinforcement

• reinforcement sizes, locations and fixing

• bond-breaker effectiveness

The inspection should be carried out by atrained and competent person who wasnot involved in the original set-up. Forstack casting, an inspection should bedone prior to the casting of each panel.

Bond-breaker effectiveness can bechecked by sprinkling water over thecasting bed. It should form into beads ifthe bond is effective.

Records should be kept to substantiate themanufacturer’s certificate of compliance.

The concrete supplier should be advisedof:

• the specified characteristic concretecompressive strength

• the concrete compressive strengthrequired at time of lifting

• the maximum aggregate size

• the slump

• special design requirements, if any, e.g.colour, cement content and water tocement ratio

• the site access, required rate of supplyand the method of placement, e.g. typeof pump

Vibrators should be used to compact theconcrete. Particular attention and careshould be paid to vibrating the concretearound the inserts and adjacent to thecorners and edges. Concrete must beplaced in a uniform manner and properlyspread over the area before commencingvibration.


36

5.10 Minimum strengthfor lifting

The minimum concrete strength at whichprecast or tilt-up concrete elements can belifted from the mould depends on:

• the concrete stresses at the lifting points

• the flexural and shear stresses causedby handling

• the stresses caused by the transfer ofprestressing forces

The strength of the concrete at initial liftmust not be less than the value specifiedon the shop drawings.

The minimum strength of the concrete atinitial lift should be determined by amethod that reflects the concrete strengthin the element.

Concrete grades higher than that specifiedby the project design engineer may berequired to develop the full capacity of thelifting inserts for early lifting, transport orerection.

5.11 Curing and release

The strength, watertightness and durabilityof concrete depend on the concrete beingadequately cured.

Release agents used in the manufacture ofprecast or tilt-up concrete elements shouldbe checked for compatibility with the

curing compound and other appliedfinishes and joint sealants.

5.12 Special provisions for on-site casting

For tilt-up panels cast on site, the floorslab is commonly used as the casting bedand erection platform.

Additional casting beds may beconstructed as required. They should bedesigned to support formwork fixings andloads. The casting bed must beconstructed of suitable materialcompatible with the tilt-up process.

Impact-driven fixings should not be usedto fix formwork if the floor slab is requiredto have a quality finish.

The builder or precaster should obtainverification from the project designengineer that the erection platform cancarry the construction loads.

Panels are usually cast with their externalface down to minimise external patchingafter erection.

To ensure that personnel are not requiredto fix a brace to a wall panel that is leaningtowards them, bracing inserts should beon the same face of the panel as the liftinginserts.


37

5.15 Modification

Modifications to precast or tilt-up concreteelements should only be carried out withthe approval of the project design engineer.

5.16 Element identification

During or immediately after manufacture,all precast and tilt-up concrete elementsmust be permanently marked with aunique identification designation,commonly the element number, and dateof casting.

5.17 Manufacturer’s certificateof compliance

Prior to the transportation or erection ofprecast or tilt-up concrete elements, thebuilder or precaster must prepare amanufacturer’s certificate of compliancestating that the manufacture of theelements was carried out in accordancewith the approved shop drawings.

The manufacturer’s certificate ofcompliance must be supplied to theerector and must be available on site at thetime of lifting the elements listed on thecertificate.

The statement should be in the form givenin appendix D.

5.13 Release agents

Before a release agent is chosen for use inthe manufacture of the precast element, itshould be checked for compatibility withthe curing compound and other appliedfinishes and joint sealants. A provenproprietary combination curing compoundor release agent should be used.Consideration should be given to thefollowing factors:

• solubility – the products should not bewashed off by rain

• discolouration – if it is a pigmentedproduct, the pigmentation shouldweather off within a reasonable time

• temperature effects – extremetemperatures may blister the productand cause it to lose its properties

• compatibility with finishes – theadherence of applied finishes, includingjoint sealants, should not be affected

The curing compound and release agentshould be applied in accordance with themanufacturer’s specifications.

5.14 Stripping and repair

Formwork should be carefully stripped toprevent damage.

If the precast or tilt-up element isdamaged, the proposed repair systemshould be submitted to, and approved by,the project design engineer before beingattempted.

Part 6:Handling and storage

38

6.1 General

This part relates to:

• the handling and storage of precastconcrete elements in the factory orcasting yard

• the storage of precast and tilt-upelements on site

• precast or tilt-up concrete elements thatare removed from an existing buildingfor reuse

There is no standard method of handlingand storage for precast or tilt-up concreteelements. Methods will vary depending onthe type of element and whether theelement is in the factory or on site. Theimportant criteria are firstly, safety ofpersonnel, and secondly, protection of theconcrete element.

As well as providing a safe workplace andprotecting the concrete element, theobjective of a handling and storage systemis to ensure safe transfer of the elementfrom the mould to the storage area andeasy access to the element for removal.

At no time should a precast or tilt-upelement be placed in a position withoutpositive restraint unless it is inherentlystable.

Inherently stable elements are thoseelements that, due to their geometry,cannot tip or rotate when stored andsubjected to wind loads, constructionloads and impact loads generated duringplacement and removal of the elementand, where appropriate, accidental impactfrom vehicles.

6.2 Handling

The general requirements for rigging andlifting systems are specified in parts 5and 8.

Handling methods may vary fromprecaster to precaster depending on thefacilities available and the types ofelements being manufactured.

Where elements require multiple handlingor rotation for processing or finishing, therigging systems and lifting insertconfigurations should be designed anddetailed on the shop drawings.

The rigging system to be used and methodof handling each element or type ofelement should be shown on the shopdrawings or set out in an appropriate workmethod statement. No element should belifted without the appropriate methodsbeing documented.

Part 6: Handling and storage cont.

39

6.3 Concrete strength forhandling

Precast or tilt-up concrete elementsshould not be removed from the mouldsand placed in storage until the concretestrength has attained the minimum valuerequired for lifting as specified on the shopdrawings.

6.4 Storage

The storage area should be large enoughfor elements to be stored properly withadequate room for lifting equipment andfor manoeuvring trucks and cranes.

The area should be reasonably level andhard surfaced with adequate drainage toensure that a safe workplace can bemaintained.

Elements should not be stored directly onthe ground. Generally, two discretesupport points should be provided unlessspecifically noted otherwise by the projectdesign engineer. Timber supports raisedabove the ground or dedicated rackingsystems should be used in all cases.

Elements should be stored in such amanner that each element supports onlyits own weight without any load beingimposed by other elements.

Where elements are stacked horizontallyon top of each other, the following shouldapply:

• support points should be directly aboveeach other unless specificallydocumented otherwise

• the stacked height of elements should belimited to ensure that the ground bearersand lowest elements can support theloads from above and that the stackremains stable

• stack height should not be higher thantwice the element width unlessspecifically documented otherwise andprovisions are made to minimise thelikelihood of accidental impact fromvehicles or other elements

Points of contact between elements andsupports should be covered withprotective material to prevent breakageand staining.

Special consideration should be given toprestressed elements to ensure that theyare only supported at designated bearingpoints. Prestressed elements shouldnever be supported, even temporarily, atany other points. Equally, they shouldnever be tipped sideways or stored directlyon the ground.


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6.5 Storage systems

Storage systems for elements that are notinherently stable must be designed toresist the loads and forces applied to them.This includes wind loads, constructionloads and impact loads generated duringplacement and removal of the elementand, where appropriate, accidental impactfrom vehicles. The design of the storagesystem should be fully documented.

To minimise the effects of vehicle andother uncontrolled impact, the elementsupport systems (racks and frames etc.)should be robust and be designed so thatfailure at one point does not result inprogressive failure. Racking systemsshould be designed so that if one elementfalls it does not create a domino effect.

Racking systems for vertically stored wallpanels should be designed andconstructed as follows:

• at least two restraint points should beprovided so that the panel is stableunder the above loads. The top restraintshould be above the mid-height orcentre of gravity of the panel

• the restraint system should be designedto withstand the loads, as noted above,as well as loads generated when thepanel is up to 5 degrees off vertical

• where necessary, provision should bemade in the design of the restraintsystem for panels with corbels and nibs,and panels should be firmly held in theracking system

The racking system should be constructedin accordance with a design prepared by aqualified engineer suitably experienced inthe field of precast concrete construction.

Frames, either single-sided, or double -sided A frames used to store wall panels,should be designed and constructed asfollows:

• the frame and its supports should bedesigned to remain stable and withstandthe forces as noted above

• panels should remain stable in the framewhen the panels are not restrained. Theslope of the panels should be such thatthe panel will not tip out of the frame

• the frame and its supports should bedesigned to accommodate unevenloading of panels. The limitations foruneven loading should be clearly shownon the frame

The frame and its supports should beconstructed in accordance with a designprepared by a qualified engineer suitablyexperienced in the field of precast concreteconstruction.


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6.6 Site storage

Generally the sequence of erection shouldbe such that storage and multiple handlingof elements on site are avoided.

When storage and multiple handling areunavoidable, the required work methodshould be clearly documented.

Storage of elements on site should be inaccordance with the general requirementsfor handling and storage and the following:

• elements should only be stored in aposition approved by the project designengineer

• ground conditions should be checked toensure that the mass of the element canbe supported

• where an element is to be stored on asuspended floor slab, approval andwritten instructions must be obtainedfrom the project design engineer beforeproceeding

• wall panels may be stored in a suitable Aframe or stood and braced in a verticalposition. Bracing should be inaccordance with the generalrequirements of this Industry Standard

• wall panels may only be storedhorizontally (“on the flat”) in accordancewith a written instruction from theerection design engineer or projectdesign engineer

Wall panels should preferably be stored inthe vertical position. Where edge-liftedpanels are stored horizontally, they shouldbe placed as originally cast to ensure thatcomponent reinforcement around edge-lifting inserts is correctly orientated forre-lifting.

6.7 Impact protection

For precast and tilt-up concrete elementsstored in areas of vehicular movement,additional protection may be required tomaintain a safe workplace. This couldinclude the use of bollards or otherphysical barriers.

During handling and storage, care shouldbe taken to minimise the likelihood ofimpact between elements.

Part 7:Transport

42

7.1 General

Secure restraint of loads on vehicles isimportant in preventing accidents andinjuries.

The transporter must ensure that any loadis securely restrained. This means that theload:

• must not be placed in a way that makesthe vehicle unsafe or unstable

• must be secured so that it is unlikely tofall or be dislodged from the vehicle and

• must be restrained by an appropriatemethod

Methods of restraint should comply withthe VicRoads publications Load RestraintGuide, Section D: A Guide to RestrainingConcrete Panels. These guides describethe performance standards that anyrestraints must meet and provideinformation on the principles ofrestraining, requirements for positioning,and how to secure loads.

The adequacy of a particular method ofrestraint will depend on the type ofelement being transported and the type ofvehicle being used.

7.2 Basic principles

Before the shop drawings are prepared,element sizes and transportability shouldbe reviewed to confirm that the proposedelements are able to be transported to thebuilding site and be erected. The feasibilityof transporting a crane of the required typeand capacity to lift the elements also needsto be taken into account. The precastermust ensure that the concrete strength ofthe precast elements has reached thedesign strength for transport and erection.

The precaster must ensure that theelements are loaded in a sequencecompatible with the required unloadingsequence on site.

Precast components should not betransported within three days of castingunless concrete in the specificcomponents is tested to confirm thatdesign strength for erection has beenattained. These test results must beavailable on site prior to erecting theelement.

The transporter must ensure that thevehicle used is suitable to transport theelements and that they are properlysecured. A vehicle must never be movedwithout the load being secured in theappropriate manner.

Part 7: Transport cont.

43

The transporter must ensure that drivershave been adequately instructed in the safetransportation of precast elements, withparticular attention given to:

• power lines

• tram lines

• train lines

• OD routes (recognised truck routes forover dimensional loads)

• roundabouts and “reverse camber in theroad”

The transporter is responsible forobtaining the permit for all overdimensional loads. Drivers must be able toproduce the permit upon request.

Vehicles used to transport precastelements should be such that the centre ofgravity of the load is as low as possible.Placement of the elements should evenlyspread the load along the vehicle’s centreline.

Where precast elements are carried on aflat top trailer, a safety chain must beplaced around the front edge of theelements to prevent forward movement.The rated safe capacity of a safety chainmust be at least half the weight of the loadit is safeguarding.

Restraint equipment and anchor pointsmust be strong enough to hold the load.The equipment should be inspected beforeuse to ensure that it is serviceable.

Elements should be loaded so thatidentification marks are visible duringunloading.

Drivers should stop and check the loadand the restraints shortly aftercommencing the journey to ensure thatthe load has not moved or settled.

7.3 Support frames

Frames used to support elements duringtransport should be designed to withstandloads and forces acting on the systemduring loading, transportation andunloading.

A frame system that is not an integral partof the trailer must be separately andindividually secured. The fixing methodmust be capable of withstanding anyforces applied during loading,transportation and unloading.

Particular care should be taken duringloading and unloading elements fromframes to ensure that the frames remainstable at all stages. Semi-trailers should bestabilised by lowering the support legsonto a firm base.


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Where unloading cannot take place on afirm level surface, elements must beindividually restrained and the loadingconfiguration must be checked to ensurethat removing individual elements doesnot result in instability of the load or thevehicle. Restraints must not be removeduntil the crane takes the initial weight ofthe element.

7.4 Element protection

Points of contact between elements,supports and restraints should beprovided with protective material toprevent breakage and staining. Cornerprotectors should be used under allrestraints to prevent movement anddamage to the element.

Where elements are transportedhorizontally, they should be stacked sothat each element can support the loadsfrom above. The support points should bedirectly above each other unlessspecifically designed otherwise.

The stacked height of elements should belimited to ensure that the bearers andlowest elements can support the loadsfrom above and that the stack remainsstable during transportation.

Special attention should be given toprestressed elements to ensure that theyare only supported at designated bearingpoints and that restraint systems do notimpose excessive loads. Prestressedelements should never be supported, eventemporarily, at any other points and theyshould never be tipped sideways.

7.5 Delivery

Delivery of the precast elements onto thesite requires cooperation between thebuilder, the transporter and the erector.

The builder must provide a recognisedtraffic control management plan thatincludes, where necessary, flagmen,barricades and road closure permits toallow unimpeded access to the site.

The precaster must ensure that thetransporter has detailed instruction onhow to enter the site.


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The transporter should inspect the siteprior to entry to verify that there are nodangers such as backfilled excavations oroverhead services. The area to receive thedelivery vehicle should be firm and level.

The transporter must position the vehicleas directed by the erector and stabilise thevehicle prior to releasing the elementrestraints. Semi-trailers should bestabilised by lowering the support legsonto a firm base. The transporter shouldbe aware of which elements are to beunloaded first.

If the unloading sequence can lead toinstability of loads, the precast elementsshould be individually secured. Individualelements should not be released until thecrane has taken the initial load of thatelement.

Under no circumstances should a vehiclebe moved without the load being securedin the appropriate manner. The transporteris responsible to ensure that the load issecured in the appropriate manner at alltimes, even during the unloadingoperation.

Part 8:Erection

46

8.1 General

Safe erection of precast and tilt-upconcrete elements depends on the pre-planning process. All personnel should beaware that erection of any precast elementis potentially hazardous and that thepurpose of the pre-planning process is toidentify hazards and control any risk in theerection process. Although the risks maybe small, the consequences of a failure canbe death, serious injury or damage to thebuilding or equipment.

8.2 Planning the constructionand erection sequence

Prior to manufacturing the precastelements, the precaster and the erector inassociation with the project designengineer and the builder, should haveplanned the complete construction anderection sequences.

The planning process should take intoaccount:

• site limitations

• local street access

• element sizes

• crane size, mobility and access

• casting sequence

• overhead obstructions, includingoverhead power lines

The planning process should ensure theon-site provision of:

• adequate and hygienic amenities for theerection crew in accordance withWorkCover’s Code of Practice forBuilding and Construction Workplacesor the WorkCover Safety Guidance NoteAmenities for Housing Construction(Cottage Industry) Sites, as appropriate

• adequate site access for the type ofconstruction methods to be employed

• adequate access for the size of the craneto be used

• adequate access for semi trailers

• serviceable height access equipmentappropriate to the construction methods

8.3 Planning cranagerequirements

Cranes and elevating work platformsshould be selected and used in accordancewith the appropriate parts of AS 2550.

Cranage planning should commence asearly as possible in development of thework or project. In the case of newbuildings or structures, architects,designers and engineers should giveconsideration to crane loadings andaccess at the initial design stage,especially where methods such as tilt-up

Part 8: Erection cont.

47

construction are contemplated and wherecranes may be supported on concreteslabs.

Planning the crane activities should bedivided into various stages including initialdesign, builder or contractor site set out,and the stage immediately prior to thecrane’s use.

Wherever feasible, the planning shouldinclude consultation with the erector.

At appropriate stages, the planningprocess should deal with:

• crane selection, access and siting inaccordance with AS 2550

• protection of the public

• the location of any excavations orunderground services likely to beadversely effected by imposed craneloads

• proximity of overhead power lines

• written procedures for setting up anddismantling of the crane and the liftingmethod

• the make-up of the rigging crewappropriate to the particularcircumstances of the job

• the communication system

• ground support conditions

• selection of lifting gear

• personal protective equipment for therigging crew

• emergency procedures

8.4 Operating near overheadpower lines

Contractors should plan ahead as far aspossible. Electricity distribution authoritiescan isolate most overhead power lineswhen sufficient notice is given.

Where overhead power lines are isolated,the electricity distribution authority’saccess permit should be kept in the craneoperator’s possession during operations.

Where there is no access permit, thepower lines must be treated as being live.


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In instances where, as depicted in figure8.1, it is necessary to operate the cranewithin 6.4 metres of power lines on polesor 10 metres of power lines on towers,

a dedicated qualified spotter must be usedthroughout these phases of the erectionsequence.

Fig 8.1: Clearance for cranes from overhead power lines

NO GO ZONEAnywhere above

Power Lineand

within 3m each side

See special provisions

3m 3m

Openarea

outside6.4m

ofPowerLines

Openarea

outside6.4m

ofPowerLines

Spotterrequiredbetween3 - 6.4m

ofPowerLines

Spotterrequiredbetween3 - 6.4m

ofPowerLines

Overhead Power Lines on Poles

NO GO ZONEAnywhere above

Power Lineand

within 8m each side

See special provisions

Openarea

outside10m

ofPowerLines

Openarea

outside10mof

PowerLines

Spotterrequiredbetween8 - 10m

ofPowerLines

Spotterrequiredbetween8 - 10m

ofPowerLines

Overhead Power Lines on Towers

8m 8m


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In these circumstances, the erector shouldimplement the following measures also:

• slow down the normal operating cycle ofthe crane to increase the availablereaction time for assessing distances

• keep persons not authorised by theerector away from the area

• clearly instruct all ground staff to standclear of the crane and load at all times

• install warning notices in a prominentposition in crane cabin to alert operatorsto check for the presence of power lines.Typical wording should be “DANGER -WATCH OUT FOR THE OVERHEADPOWER LINES”

• dry taglines (tail ropes) made of naturalfibre such as hemp, sisal or other non-conductive material should be used tocontrol the load. Due to their conductiveproperties, synthetic ropes must not beused. The tagline should be preventedfrom approaching or being blown intocontact with any power line

• mobile cranes should be provided withan earthing chain with links of at least10 mm in diameter. The chain should bebolted or welded to the carrier chassisand be of sufficient length to allow atleast one metre of chain to be in contactwith the ground when the crane is set up

on outriggers. It is important to notethat the earthing chain should not beused when the crane is set up withcarrier within six metres of the rails ofan electric train system

• when operating or travelling in anunfamiliar area, the crane operatorshould check for the presence ofoverhead power lines

In the event that the crane does contactlive power lines, the crane operator shouldobserve the following precautions:

• remain inside the cabin

• warn all other personnel to keep awayfrom the crane and not to touch any partof the crane, rope or load

• try, unaided, and without anyoneapproaching the machine, to move thecrane until clear of the power line

• if the machine cannot be moved away,remain inside the cab. If possible, getsomeone to inform the electricitydistribution authority at once. Take noaction until the distribution authority hasconfirmed that the conditions are safe

• if it is essential to leave the cabinbecause of fire or other life-threateningemergency, jump clear as far away fromthe crane as possible. Do not touch thecrane and the ground at the same time


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• when moving away from the crane,shuffle or hop slowly across the affectedarea. Large steps should be avoided asone foot could be in a higher voltagearea and the other in a lower voltagearea. Under some circumstances, thevoltage difference between the two areascould kill (see figure 8.2)

• inform the electricity distributionauthority of the situation immediately.Until assistance arrives, someoneshould remain near the crane, but at asafe distance, to warn others of thedanger of approaching

Following any contact with live powerlines, a competent person should inspectthe crane for possible damage caused bythe contact before further use. Wire ropeshould be replaced if it touches the powerline as the arc will usually weld, melt orbadly pit the rope.

Proximity warning devices, insulatingboom guards and similar devices all havelimitations and should not be relied uponto give protection against electric shock.

Fig 8.2: High voltagecontact

High voltage contact will result in electrical current flowing downthe boom and through the crane to the ground. The ground willthen be energized with a high voltage near the crane andlower voltage further away.


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8.5 Erection preparation

Before erection commences, the builderand erector should:

• confirm that the erector’s riskassessment is appropriate and has dealtwith all aspects of the erectionprocedure

• inspect crane access to the site and theerection platform and confirm that it issafe

• obtain verification that the erectionplatform can safely support the erectionloads

• make sure the immediate area for truckand crane access has been cleared toprovide adequate room for craneoutriggers, counterweight tail swing,boom swing, and under-hook andoverhead obstructions

• make sure that sufficient clear space isavailable for the safe propping or panelbracing of the precast or tilt-up elements

• make sure that the locating dowels andlevelling shims are correctly located;

• make sure that adequate temporary baserestraint is provided for any pre-castelement to prevent a sliding failure (kick-out) at the base or support of theelement

• confirm that the means of support,including falsework, is adequate for theintended purpose and is correctlylocated

• verify that the element concrete hasattained the specified strength for lifting

• verify that the brace footing concrete hasattained the specified strength

• check that the strongbacks, if required,are available and are correctly installed

• determine if it is necessary to equaliseloads on lifting points

• ensure that the appropriate riggingequipment is available and is serviceable

• check that the lifting inserts are in theircorrect location and that recesses arecleaned out in preparation for lifting

If incorrectly located, faulty or missinglifting inserts are identified, immediatecontact should be made with the precasterto establish an appropriate solution.

8.6 Crane capacity andoperating radius

The rated capacity or working load limit(WLL) of a crane refers to its maximumload capacity at the minimum radius. Thisshould not be confused with its actualcapacity at working radius when lifting.


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The required crane capacity is determinedby several factors including the distancefrom the centre of rotation of the crane tothe centre of gravity of the precast elementbeing lifted. The capacity of a cranedecreases as the distance of the loadincreases from the centre of rotation of thecrane.

Precast elements are usually lifted atextended radii and this will usuallydetermine the required crane capacity,rather than the maximum element weight.Crane charts should be referred to for thecorrect selection of cranes.

For all face-lifted wall panels, the trueworking radius of the crane should includean allowance over the radius to the panel’sfinal position to take account of the hangof the panel from the lifting inserts and anylifting beams etc. (see figure 5.1). Anassessment of the true working radiusshould be made according to individualpanel details. The necessary increase inradius may be 1.5 m or greater.

Where it is necessary to use two cranes to“dual lift” elements, the required cranecapacities should be carefully assessed.Under no circumstances should thecapacity of either crane be less than 70%of the mass of the element. For furtheradvice on multiple crane lifting, refer tochapter 18 of WorkCover’s A Guide toRigging.

8.7 Erection crew

The erector must nominate one person inthe erection crew to be directly responsiblefor the direction and coordination of theerection sequence. This person must holda rigging certificate of competency ineither the Intermediate Rigging OrAdvanced Rigging certificate classes(class codes RI or RA).

The crane operator must hold, or be underthe direct supervision of the holder of acertificate of competency appropriate forthe type of crane and, in the case of aslewing mobile crane, the crane’s capacity(WLL).

The size and make-up of the remainder ofthe erection crew will vary depending uponthe nature of the site and the particularcircumstances. As a general rule, it shouldalso include at least one additionalcertificated rigger (holding at least theBasic Rigging – RB – certificate class) andadditional appropriately skilled persons asrequired.

At least one of the erection crew,preferably the rigger in charge of the crew,should have been trained in this IndustryStandard.

At least one of the erection crew or anotherperson who remains on site throughouterection should hold a current qualificationas a Level 2 First Aider.


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8.8 Erection platform

Before erection commences, the buildershould supply the erector with writtenverification that the erection platform(floor slab, suspended slab, surroundingground etc.) can safely carry theconstruction and erection loads.

Backfilled excavations and trenches shouldbe identified and assessed. Additionalmeasures, such as the provision of timbermats, may need to be taken to ensure thatany backfilling can support theconstruction and erection loads.

If a suspended slab is used to support thecrane, the slab should be designed for thecrane point loads. A suitable proppingsystem may be required and, if so, shouldbe designed in accordance with therequirements of the appropriate AustralianStandards.

8.9 Rigging

Setting up a rigging system requirescareful and thorough pre-planning. Theselection of the rigging system connectingthe precast or tilt-up element to the craneshould be agreed between the precasterand erector. The selected configurationmust be specified in the shop drawingsand must not be altered without theapproval of the precaster or the erectiondesign engineer.

Reusable lifting devices (lifting clutches)must be designed and manufactured sothat the failure load is five times their WLL(i.e. with a design factor of 5.0).

The rigging system should distribute equalloads to all lifting points unless specificallydesignated otherwise on the shopdrawings.

Where offset lifting arrangements areused, the increase in load applied toparticular lifting inserts must be taken intoaccount in selecting the capacity of thelifting insert.

Sling lengths are critical where the riggingsystem includes the use of spreaderbeams or lifting beams with slings runningthrough sheaves. The rigging systemshould be designed to suit the spacing andlayout of the lifting inserts.

Single, double and four-leg slings arecommonly used in the handling of precastelements. In selecting the sling capacity,the increased force due to inclination ofthe sling and the change of direction atreeving points should be considered. Theincluded angle between slings at reevingpoints should not exceed 120 degrees.

When lifting precast elements with fixedlength multi-legged slings, any two legs ofthe slings must be capable of supportingthe total load.


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The rigging system should be arranged toallow the precast element to lie in or nearits correct attitude for erection into thestructure. This can be accomplishedthrough one or more of the followingmeans:

• appropriate location of the lifting inserts

• use of a lifting beam with offset liftingpoints

• correct location of the slinging point orpoints in the element

• use of a counterweight

Where possible, three rows of insertsshould be avoided due to the complexrigging configurations required. Preferredconfigurations are shown in figure 4.1.

Where precast elements need to be rotatedby use of a tailing lifter (lifting insert at thebottom of the element), the requiredcapacity of the crane winch being used torotate the element must be determined.

Up to 70% of the mass of the element canbe taken by the tail lifter during rotation.This is particularly critical for edge-liftedwall panels (see figure 8.3).

General rigging practices not dealt withspecifically in this Industry Standardshould be consistent with the adviceprovided in WorkCover’s A Guide toRigging.

Fig 8.3: Tailing lifters

Rigging to tailing hoist

Tailing lifteror lifters

Rigging to main hoist


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8.10 Strongbacks

Panels that are odd-shaped, elongated, orwith large or awkwardly located openingsare often strengthened for lifting by theaddition of strongbacks.

Strongbacks must be located and fixed inaccordance with the details shown on theshop drawings.

The mass of the strongbacks is to beincluded when assessing the load on thecrane.

Any changes to the specified strongbacksystem must not be made without theapproval of the shop detailer.

8.11 Erection sequence

Precast and tilt-up elements should beerected in accordance with the pre-planned sequence referred to in part 4.

Elements must not be lifted or erectedbefore attaining the minimum concretestrength on the shop drawings for lifting orerection.

Elements must not be erected on sitewithin three (3) days of casting unless theconcrete in the specific elements has beentested to confirm that the design strengthfor erection has been attained. Test resultsmust be available on site prior to erectingthe element.

The builder must provide the erector withverification that the concrete in bracefootings has attained its required strengthbefore elements are erected.

The lifting and placing method mustensure that a sudden failure of the elementor rigging will not endanger the craneoperator or the crane.

8.12 Erection of tilt-up panels

For panels cast on site, the adhesion of thepanel to the casting bed has to be broken.

For face-lifted panels, lifting must bestopped if the panel does not come freewhen the crane’s load indicator registersthe combined mass of the panel, riggingand any attachments such as strongbacks.

For edge-lifted panels, lifting must bestopped if the panel does not come freewhen the crane’s load indicator registers60% of the weight of the panel plus 100%of the weight of the rigging and anyattachments such as strongbacks.

In these circumstances, procedures suchas wedging or jacking should be asdetermined by the shop detailer. Suchprocedures should be undertaken ordirectly supervised by the rigger in chargeof the erection.


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Whenever possible, braces should be fixedto the panel before it is lifted.

The following rules apply during the liftingand placing of panels:

• whenever possible, panels should belifted with the rigging equipment in viewof the crane operator

• all personnel must be outside the dropzone when lifting, tilting or rotating thepanel from horizontal to vertical

• when taglines (tail ropes) are used tocontrol the swing of the panel, personnelmust position themselves clear of thepanel edges as the panel may slewsideways

• under no circumstances should anyworker position themselves underneatha precast element or on the underside ofa tilt-up panel during erection

• no attempt should be made to lift anderect panels in strong winds wherecontrol of the panel may be lost (it is theresponsibility of the rigger in charge, inconsultation with the erection crew, todetermine that conditions are suitablefor erection to proceed)

• where it is necessary to attach braces tothe panel after it has been positioned,the panel must be held firmly and safelyby the crane while the braces areattached

• a minimum of two braces should beconnected before releasing the liftingequipment, unless otherwise specifiedon the shop drawings (two braces maynot be necessary where wall panels areprovided with erection brackets orpermanent connections to otherrestrained elements such as steel portalcolumns or precast walls forming astable “box” structure)

• under no circumstances should there beless than two connections providingsupport to each precast element unlessspecifically designed and detailed andapproved by the project design engineer

• no brace should be connected to anotherpanel for support unless clearly specifiedon the shop drawings


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8.13 Erection of other precastelements

The mass of all elements should becalculated prior to the commencement oferection. This information should beshown on the shop drawings and madeavailable to the erection crew.

The shop detailer should determine theconfiguration of the required rigging andlifting equipment in consultation with theerector.

The lifting equipment should be attachedto the precast elements by a competentperson and the immediate area should becleared in preparation for lifting.

Taglines (tail ropes) may be required insome circumstances.

Under no circumstances should personnelpass or stand beneath a suspendedelement.

The effect of wind upon the safe handlingand erection of elements must be takeninto account.

8.14 Levelling shims

Levelling shims carry the load of the pre-cast or tilt-up concrete element that mustbe supported adequately to preventmovement until it is incorporated in themain structure.

Levelling shims must be manufactured tocomply with the relevant requirements ofAS 3850.

Levelling shims must be used on solidfoundations that are designed to carry theimposed loads.

Shimming should be limited to amaximum height of 40 mm and aminimum width of 100 mm unlessspecifically designed otherwise. Where thetotal shim height is greater than 40 mm,steps should be taken to ensure stability.


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Where practical, shims should be locatedat least 200 mm in from the ends of theelement, unless otherwise specified. Thisis particularly relevant for thin wall panelswhere edge breakout can occur if shimsare placed too close to bottom corners(see figure 8.4).

Direct concrete-to-concrete, or concrete-to-steel bearing should be avoided unlesssome edge spalling and cracking isacceptable to the builder.

The gap between the bottom of theelement and the footing should be groutedor dry packed to transfer the load to thefootings.

Fig 8.4: Levelling shims

Wall panel

150mm MIN

200mm(unless otherwise stated)

Shims Grout betweenpanel and footing

40mm MAX


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8.15 Fixing inserts

Where permanent fixings or connectionsare to be utilised for temporary use duringconstruction, the builder or the erectorshould verify that the fixings are suitablefor the temporary use and that such usewill not compromise their long-termperformance.

8.16 Missing or unusablelifting inserts

If incorrectly located, faulty or missinglifting inserts are identified, immediatecontact should be made with the shopdetailer to establish an appropriatesolution.

Solutions could include:

• fixing a plate with undercut anchors

• fixing a plate with chemical anchors.Anchors must be individually prooftested

• drilling through the element andattaching lifting plate(s) by bolting

All of the above solutions must have aWLL based on a design factor of at least2.5 against failure.

Expansion inserts should not be used aslifting points.

8.17 Temporary bracing

Braces are temporary componentsproviding stability in preventing a tilt-up orprecast concrete element fromoverturning.

All elements should be braced inaccordance with the requirements of theshop drawings. The shop drawings shouldspecify the required bracing forces andshow details of the fixings to the elementand the bracing footing.

Brace footings are to be in accordancewith the requirements of the shopdrawings and, in particular, the specifiedconcrete strength of the footing at the timeof erection. The location of bracing insertswithin the brace footing must also be asspecified in the shop drawings.

Braces must be maintained and inspectedbetween each use to ensure that allcomponents are correct and in goodworking order.

Brace feet or shoes must be of a type thatwill physically prevent lateral displacementof the shoe from the insert connectionsafter installation.


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Braces must be marked as set out insection 4.11.

Brace adjustment mechanisms must havestops on the threads to prevent over-extension and retaining devices to preventunintentional dislodgment of the shearpins. The shear pins should beconstructed so that they cannot be undonewithout the use of a tool.

Whenever possible, the braces should befixed to the precast or tilt-up concreteelement before lifting.

Bracing insert capacities are sensitive to:

• the method of installation

• the strength of the concrete into whichthey are placed

• the distance from the insert to the edgeof the element

Unless specified otherwise in the shopdrawings, bracing inserts must not becloser than 300 mm to the edge of theelement, footing or other bracing support.

During the lifting process, the bracesshould not hang below the base level ofthe element. This may be achieved by theuse of adjustable brace lengths or by theuse of taglines (tail ropes).

For face-lifted wall panels, bracing insertsshould be on the same face of the panel asthe lifting inserts.

When, under unusual circumstances, it isnecessary to attach the braces after a wallpanel has been positioned, the wall panelshould be held firmly, safely and just pastvertical by the crane while the braces areinstalled.

Until it is secured, no one should everwork on a panel that is leaning towardsthem.

Generally, a minimum of two bracesshould be used for all tilt-up and precastelements.

Two braces may not be necessary whereelements are provided with erectionbrackets or permanent connections toother restrained elements such as steelportal columns or precast walls forming astable “box” structure.

If expansion anchors are to be used asbracing inserts in the floor or bracefootings, the type and their capacityshould be assessed in accordance withpart 4 and should be clearly specified onthe shop drawings.


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After erection, it is the builder’sresponsibility to check braces, bracingbolts and pins at regular intervals toensure that they maintain the requiredcapacity.

Prior to the removal of braces, it is theresponsibility of the erection designengineer or the project design engineer toinspect the structure to ensure that allstructural elements affecting stability aresecurely fixed to the precast or tilt-upconcrete elements. A written instructionauthorising the removal of the bracesshould then be supplied.

It is the responsibility of the builder toensure that no brace is removed withoutwritten instructions from the erectiondesign engineer or project designengineer.

It is the responsibility of the brace ownerto inspect and service the braces at regularintervals and to keep service records.

8.18 Temporary propping

Props are temporary componentssupporting loads which producecompression forces.

Propping systems should allow forpossible changes to the distribution ofloads during the construction process.

Where beams are post-tensioned aftererection, the stressing process will changethe shape of the member, thereby reducingthe load on some props and increasing theload on others. This particularly applieswhere the stressing induces a camber intothe beam which can lift the beam off propsat mid-span, transferring all the load to theprops at the ends.

Where the seating for precast beams cannot transfer loads during construction, thebeams must be propped at each end tocarry the full load.


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Where beams are to have floor systemsplaced on them prior to the beams beingfully built into the structure, allowanceshould be made for uneven loading on the

beam during construction. With floor unitsplaced only on one side of a beam,additional temporary propping may berequired to each edge of the beam (seefigure 8.5).

Fig 8.5: Uneven erection loading

Precast floor unitOVERTURNING TORQUE

Column top orcolumn bracket

Precast beam


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Where required, all temporary proppingshould be in place and fully braced prior tocommencement of erection of any precastelements.

Unless specifically detailed otherwise,temporary propping should provide fullsupport to all construction loads includingthe full self-weight of the completed floorsystem and possible local concentrationsof load during construction. Constructionloads may include reinforcing steel orexcess concrete.

Subject to the precaster’s work methodstatement, it may be satisfactory to erecttemporary props after the precast floorunits are in place, and for the props to takeonly a portion of the full construction load.

Props should be vertical. They should alsobe braced to prevent side-sway of thewhole assembly and the buckling ofindividual props.

Props should be adequately seated,levelled and capable of transferring the fullload through whatever structure they arebearing on and into the ground withoutadverse settlement.

The shop drawings should clearly specifythe required propping forces and showdetails of the fixing to the precast elementand the prop footing.

Prop footings are to be in accordance withthe requirements of the shop drawingsand, in particular, the specified concretestrength of the footing at the time oferection.

Prior to the removal of props, it is theresponsibility of the erection designengineer or project design engineer toinspect the structure to ensure that allstructural elements affecting stability aresecurely fixed to the precast or tilt-upconcrete elements. A written instructionshould be supplied prior to the removal ofprops.

It is the responsibility of the builder toensure that no prop is removed withoutwritten instructions from the erectiondesign engineer or project designengineer.


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8.19 Modifications

Modifications to precast elements shouldonly be carried out with the approval of theproject design engineer.

8.20 Compliance requirements

Prior to lifting any tilt-up or precastelement, the erector must be providedwith:

• the project design engineer’s certificateof compliance

• the manufacturer’s certificate ofcompliance

• the component schedule

The component schedule must beprovided by the precaster and mustinclude the following information:

• project name and address

• element designation

• element mass

• concrete strength required at the time oferection for the element and, whereapplicable, the bracing footing

• type, capacity and length of the liftinginserts

• a diagram of the rigging system(s)between crane and precast element forboth rotation and erection

The information required for thecomponent schedule may be included aspart of the shop drawings or layoutdrawings. The shop drawings may be usedto form the component schedule.

Part 9:Proprietary elements

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9.1 Application

This part relates to precast elements thatare manufactured by a mechanical processin a factory environment. Such proprietaryelements are frequently based on specificdesign processes that are only available tothe precaster and where the component isusually supplied on a design andmanufacture basis.

Examples of proprietary elements include:

• hollowcore floor slabs

• transfloor slabs and beams

• ultrafloor beams and infills

Proprietary elements are deemed-to-satisfy the overall requirements of thisIndustry Standard if they comply with thefollowing clauses and with the intent of theremaining parts of this Industry Standard.

9.2 General design provisions

Where the precaster is responsible for thedesign of the elements, the precaster mustensure that the design complies with allthe requirements specified by the projectdesign engineer.

The design must be in accordance with therelevant Australian Standards or, wherenot specifically covered by AustralianStandards, the relevant sections of US orEuropean standards.

Design computations must be prepared bya suitably experienced engineer andcertified by a registered buildingpractitioner in accordance with therequirements of the Building Act 1993.

Design computations or suitablecertification for the proprietary elementsmust be submitted to the project designengineer for review and for verification ofcompliance with the overall designrequirements.

9.3 Design for erection

The design for erection should complywith the requirements of part 4, includingthe section on special provisions.

Shop drawings must be prepared andissued to the builder for approval andreview by the building designer and projectdesign engineer.

9.4 Manufacture

Elements must be manufactured inaccordance with a work method statementprovided by the precaster. The workmethod statement should comply with thegeneral requirements of this IndustryStandard and specifically address theissues relating to the manufacturingprocess of the elements in question.

Part 9: Proprietary elements cont.

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The manufacturing process is theresponsibility of the precaster who mustensure that it is conducted in compliancewith the Occupational Health and SafetyAct 1985, relevant OHS regulations andany other relevant statutory requirements.

Documentation associated with themanufacturing process must be availablefor inspection and auditing.

9.5 Storage

Elements must be stored in accordancewith a work method statement provided bythe precaster. The work method statementshould comply with the generalrequirements of this Industry Standardand specifically address the issues relatingto the storage of the elements in question,including any special requirementsspecified by the project design engineer.

Storage is the responsibility of theprecaster who must ensure that it isconducted in compliance with theOccupational Health and Safety Act 1985,relevant OHS Regulations and any otherrelevant statutory requirements.

Documentation associated with thestorage process must be available forinspection and auditing.

9.6 Transport

Elements must be transported inaccordance with a work method statementprovided by the precaster. The workmethod statement should comply with thegeneral requirements of this IndustryStandard and specifically address theissues relating to the transport of theelements in question including any specialrequirements specified by the projectdesign engineer.

The method of transportation is theresponsibility of the precaster, who mustensure that it is conducted in compliancewith the Occupational Health and SafetyAct 1985, relevant OHS regulations, roadtransport legislation and any other relevantstatutory requirements.

Documentation associated with thetransportation process must be availablefor inspection and auditing.

Part 9: Proprietary elements cont.

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9.7 Erection

By definition, proprietary elements willhave a specific lifting and erectionprocedure.

Proprietary elements must be erected inaccordance with a work method statementprovided by the precaster. The workmethod statement should comply with thegeneral requirements of this IndustryStandard and in particular the sectiondealing with special provisions in part 4. Itshould also address the issues specificallyrelating to the erection of the elements inquestion.

Consideration should be given to thespecific requirements for bracing,propping and fixing of elements duringerection.

Issues such as site safety and handling ofthe elements must be clearly describedand dealt with.

The work method statement must beapproved by the builder and be reviewedby the project design engineer.

Once approved, the precaster or erectormust not modify the work methodstatement without resubmitting it forapproval.

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Appendix A: Referenceddocuments and further reading

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Acts referenced• Building Act 1993

• Occupational Health and Safety Act1985

WorkCover publicationsreferenced• A Guide to Rigging

• Code of Practice for Building andConstruction Workplaces

• Code of Practice for First Aid in theWorkplace

• Guidance Note for Amenities onHousing Construction (CottageIndustry) Sites

• Guidance Note for Use of Anchors asBracing Inserts in Precast ConcretePanels

• WorkCover Incident Notification

Australian Standards referenced• AS 1170.2, Minimum Design Loads on

Structures, part 2: Wind Loads

• AS 1311, Steel Tendons for PrestressedConcrete – 7-wire Stress-relieved SteelStrand Tendons in PrestressedConcrete

• AS 1379, Specification and Supply ofConcrete

• AS 2550, Cranes – Safe Use

• AS 3600, Concrete Structures

• AS 3610, Formwork for Concrete

• AS 3850, Tilt-up ConcreteConstruction*

Note: *This Standard has undergonereview and revision. It is expected to bepublished in its revised format during2001.

Appendix A: Referenced documents and further reading cont.

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Other documents referenced• Building Code of Australia, published by

the Australian Building Codes Board

• Load Restraint Guide, Section D: AGuide to Restraining Concrete Panels,published by VicRoads

• Planning and Design Handbook onPrecast Building Structures, publishedby the Federation International Beton,FIP/FIB

• Z10: Recommended Practice, Designof Tilt-up Concrete Wall Panels,published by the Concrete Institute ofAustralia

Further reading

Precast concrete and tilt-up concreteelements should be designed andconstructed in accordance with theBuilding Code of Australia and relevantAustralian Standards and codes ofpractice.

Overseas codes and design referencesmay be used for guidance whereAustralian Standards and Codes ofPractice do not cover a particular aspect.

Additional and more detailed informationcan be obtained from other organisationsand some of these documents are listedbelow:

American Concrete Institute

• Tilt-up Concrete Structures,ACI 551R-92

• Tilt-up Construction, SCM-20 (89)

Canadian Prestressed Concrete Institute

• Design Manual, Precast andPrestressed Concrete

Cement & Concrete Association ofAustralia

• Tilt-up Construction Notes

Concrete Institute of Australia

• Z4: Recommended Practice, Designand Detailing of Precast Concrete

Elliott, Kim S.

• Multi-Storey Precast Concrete FramedStructures, Blackwell Science, 1996

National Precast Concrete AssociationAustralia

• National Precaster (Newsletter)

New Zealand Concrete Society

• Guidelines for the use of StructuralPrecast Concrete in Buildings

Appendix A: Referenced documents and further reading cont.

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Precast Concrete Institute, USA

• Erection Safety for Precast andPrestressed Concrete

• PCI Design Handbook

Portland Cement Association, USA

• Connections for Tilt-up WallConstruction

In addition to the above organisations andpublications, the manufacturers of thehardware associated with the precast andtilt-up concrete industries all publishdesign and technical information on theirproducts. Reference should be made tothe particular supplier’s technicalinformation before specifying or using anyof their products.

Appendix B: Definitions of termsused in this Industry Standard

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B1: General definitions

builder

The company or person responsible forthe construction of the completed buildingand who has control of the building site.The builder may also be the client or acompany or person responsible to theclient.

building designer

The project architect or project designerresponsible for the design of the building.The building designer will usually beresponsible to the client.

client

The owner of the building or the companyor person responsible for developing thebuilding.

erector

The company or person responsible forerecting the precast or tilt-up concreteelements. The erector may be responsibleeither to the builder, precaster, or client.

erection design engineer

The engineer responsible for the design forthe erection of the precast elements of thebuilding. The erection design engineershould be a person qualified formembership of the Institution of EngineersAustralia, be a registered building

practitioner and be competent to practicein the structural engineering field. Theerection design engineer will usually beresponsible to the builder, the precaster orthe shop detailer, or may also be theproject design engineer.

precaster

The company or person responsible formanufacturing the precast or tilt-upconcrete elements. The precaster willusually be sub-contracting to, and beresponsible to, the builder. The precastermay sometimes be referred to as theprecast concrete manufacturer or tilt-upmanufacturer.

precast concrete element

A concrete element manufactured undercontrolled conditions in a factory orcasting yard and subsequently transportedto and erected on a building site.

project design engineer

The consulting engineer responsible forthe engineering design of the building. Theproject design engineer should be aperson qualified for membership of theInstitution of Engineers Australia, be aregistered building practitioner and becompetent to practice in the structuralengineering field. The project designengineer will usually be responsible to theclient.

Appendix B: Definitions of terms used in this Industry Standard cont.

73

shop detailer

The person responsible for preparing theshop drawings of the elements. The shopdetailer may also be the precaster or acompany or person responsible to theprecaster. The shop detailer should be aperson who, through training orexperience, is qualified to undertake thework as described in this document.

tilt-up panel

A flat concrete panel, frequently cast in ahorizontal position, lifted by rotation aboutone edge until in a vertical or near verticalposition, which may then be lifted intoposition where it may be temporarilybraced until incorporated into thepermanent structure. It may be cast on siteor off site. The term does not cover otherprecast concrete elements such ascolumns, beams, flooring panels and non-rotated facade panels.

transporter

The company or person responsible fortransporting the precast concrete element.The transporter may also be the precasteror a company or person responsible eitherto the builder, precaster or erector.

B2: Technical definitions

braces

Temporary components providing stabilityin preventing a tilt-up or precast concreteelement overturning. Both ends are fittedwith a pinned foot, allowing a degree offreedom for variable fixing angles. Theyare intended to resist horizontalconstruction and wind loads.

bracing insert

A component or system cast into or fixedto the element or into an elementsupporting member for later attachment ofa temporary brace.

connections

A method by which one or more elementsare joined together. The purpose ofconnections is to transfer load and/orprovide stability.

design factor

The number by which the failure load isdivided to give the working load limit(WLL). This was previously referred to asthe safety factor.


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edge-lifting

A method of lifting whereby lifting insertsare cast within the element edge so thatthe element is lifted and hangs verticallyfrom that edge.

erection platform

The base on which the crane is supportedduring erection of the elements.

face-lifting

A method of lifting whereby lifting insertsare cast within the face of an element sothat when the element is lifted it hangs atan angle to the vertical.

fixing insert

A component or system cast into or fixedto the element and used to tie the elementinto the structure or support otherstructural members.

fixings

The hardware component of connections.Fixings provide for load transfer betweenthe members being connected.

joints

The gap between adjoining elements orbetween an element and some otherportion of the structure. Joints may behorizontal, vertical or inclined.

levelling shims

A single or series of thin strips ofappropriate material used under elementsto support the element in its correctposition until the final connection is made.

lifting beam

A device within the rigging system thattransfers the load from the element to thecrane hook by acting in bending.

lifting clutch

A quick-release device used to connect thecrane rigging to the lifting insert.

lifting insert

A component or system cast into or fixedto the element for lifting the elementduring erection.

lifting spreader

A device that spreads the lifting ropes andis in compression.

proprietary components

Components manufactured in a factoryenvironment and carrying a trademark orregistered name.

proprietary elements

Precast concrete elements that aremanufactured by a mechanical process ina factory environment.


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props

Temporary components supporting loads,which produce compression forces. Bothends of the prop are fitted with rigid footplates that provide support between twoparallel surfaces.

reinforcement

structural reinforcement

Reinforcement, including reinforcingsteel and prestressing tendons providedfor crack control or to resist forcescaused by applied loads and thermal andshrinkage movements.

additional reinforcement

Reinforcement additional to thestructural reinforcement provided toresist forces caused by transport orerection loads.

component reinforcement

Reinforcement placed in conjunctionwith lifting, bracing and fixing inserts sothat they can attain their designcapacities. Note that componentreinforcement is normally specified bythe insert supplier and may not alwaysbe shown on the shop drawings.

rigging system

A mechanism that may include a series ofslings, sheaves, lifting or spreader beams,or other mechanical devices to connect thecrane to the element being lifted.

reusable lifting equipment

The lifting device that is directly connectedto the lifting insert e.g. a lifting clutch orbolt-on bracket.

shear cone failure

The type of failure achieved when tensionis applied to an insert embedded inconcrete. When failure occurs a ‘cone’ ofconcrete as well as the insert is pulledfrom the main body of the element.

shop drawing

A detailed drawing of an element used inthe manufacturing process.

strongback

A temporary member fixed to an elementto provide localised strengthening of theelement during lifting, transport orerection.

tagline or tail rope

A fibre rope attached to the element beingerected to help control the element duringlifting and placement.

WLL (working load limit)

The maximum unfactored load that may beapplied to an item, component or system.

Appendix C: Erection designengineer’s certificate of compliance

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Site name ______________________________________________________________

Site address ______________________________________________________________

Company employing the erection design engineer _________________________________

___________________________________________________________________________

This is to certify that the erection design and detailing for the above project as carried out bythis firm is in accordance with:

• AS 3600 and/or AS 3850 (as appropriate), and

• The Victorian Industry Standard Precast and Tilt-up Concrete for Buildings

Name ___________________________________________________________________

Signature ________________________________________________________________

Building practitioner’s registration number_______________________________________

Date ____________________________________________________________________

The person completing and signing this certificate must be an engineer, a person qualifiedfor corporate membership of the Institution of Engineers Australia (or equivalent), aregistered building practitioner and be competent to practise in the design of precastconcrete.

Appendix D: Manufacturer’scertificate of compliance

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Precast and tilt-up concrete elements

Project __________________________________________________________________

Site address ______________________________________________________________

Precaster/manufacturer _____________________________________________________

Builder __________________________________________________________________

Project design engineer _____________________________________________________

Identification Castingnumber date

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

Identification Castingnumber date

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

___________________________________

This is to certify that the abovelisted precast or tilt-up concrete elements have beenmanufactured in accordance with the approved shop drawings.

Name ______________________________________________________________________

Signature ___________________________________________________________________

Date _______________________________________________________________________

Schedule of elements

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