Bondek II

BONDEK® IIFormwork And Installation

2 © June 2003 BHP Steel Lysaght Singapore

BHP Steel Lysaght(Singapore) Pte Ltd

Established in Singapore in 1965,BHP Steel Lysaght (Singapore) PteLtd is a wholly owned subsidiary ofBHP Steel Limited, the largest steelgroup in Australasia.

A manufacturer and a supply-and-fixtotal solution provider, BHP SteelLysaght Singapore offers steel andnon-steel (titanium zinc, copper,stainless steel and paintedaluminum) roofing and wallingprofiles such as KLIPLOK® 406,SPANDEK®, TRIMDEK®, SELECT

SEAM®, LOCKED SEAM™, V-CRIMP®,EASYCLAD® and PRESTIGE PANEL™.

BHP Steel Lysaght Singapore alsomanufactures a full range of C & Zgalvanized purlins from web size of100mm to 300mm.

We are also a market leader in thedesign and supply of structuraldecking such as LYSAGHT BONDEK® II,and the new millennium steeldecking – POWERDEK™.

SMARTRUSS™ is our new andinnovative way of construction inlight gauges, high strength steeltrusses offered to the market assteel intensive building solution.

BHP Steel Lysaght Singapore alsooffers customers withcomprehensive range of technicaland consultancy services. Thesevalue-added services distinguish thecompany from other manufacturersand suppliers of steel buildingproducts.

The commitment to continuousresearch, development andinnovation together with thepractice of quality assurance at alllevels and keeping abreast with thedynamics of the building andconstruction technology, has earnedthe Company the trust andconfidence of its customers.

In March 1993, BHP Steel LysaghtSingapore obtained accreditationfrom Lloyd’s Register QualityAssurance for the ISO9002 QualityManagement System.

In July 1997, the company wasconferred the Singapore QualityClass Award (SQC) status for havingachieved a commendable level ofperformance on the quality journeytowards business excellence.

In April 1998, we received theSingapore National ProductivityAward for outstandingachievements in productivitymovement and in November 2001,were also awarded by the Building& Construction Authority forachieving an exemplary level ofinnovativeness in the BAUCONASIA exhibition.

In June 2002, BHP Steel LysaghtSingapore also obtainedaccreditation from Lloyd’s RegisterQuality Assurance for theISO14001: 1996 EnvironmentalManagement System Standard.


LYSAGHT BONDEK® profiled steelsheeting was developed in the mid1960s. Since its inception it hasbeen widely accepted by thebuilding construction industry to bea highly efficient, versatile androbust formwork and reinforcement.It has been used to great effect onmany major building projects.

Since1986 Lysaght has funded amajor research investigation at BHPResearch - Melbourne Laboratories(BHPR-ML) into the behaviour ofcomposite slabs. As a result it hasbeen possible to transform BONDEK

profiled sheet into new LYSAGHT

BONDEK® II without significantlychanging its familiar profile shape,while dramatically improving its

IntroductionLysaght Bondek® II

effectiveness as longitudinal tensilereinforcement. Embossing the topsof the ribs has been important inthis regard, and in long uniformly-loaded spans the full tensilestrength of the sheeting can now bedeveloped. In such situations it isthen more effective than the samearea of deformed bars or weldedwire fabric due to its higher yieldstrength and larger effective depth.

Subsequently a very extensive seriesof tests on LYSAGHT BONDEK® II

profiled sheet has been performedin order to thoroughly investigate itsstructural behaviour as formwork,and as longitudinal reinforcement inone-way composite slabs.Comprehensive design rules, in

accordance with British Standard BS5950: Part 4: 1982 “Structural Use ofSteelwork in Building - Code ofPractice for Design of Floors withProfiled Steel Sheeting”, have beenprepared for both situations (seereferences (1) and (2)). The results offire tests performed at BHPR-ML onBONDEK composite slabs have alsosupported the development of rulesfor designing unprotected LYSAGHT

BONDEK® II composite slabs for fireresistance in accordance with BS5950: Part 8: 1990 -Structural Use ofSteelwork in Building - Code ofPractice for Fire Resistant Design”(see reference (3)). Design Manualshave been prepared from thesedesign rules.


References (BHPR-ML ResearchReports)

(1) Patrick M and Poh KW, “Designof Floors with LYSAGHT BONDEK® II

Profiled Steel Sheeting to BritishStandards, Part A - PermanentShuttering”, BHP Research ReportNo. BHPR/ENG/R/92/086/PS641Q,October, 1992.

(2) Patrick M and Goh CC, “Designof Floors with LYSAGHT BONDEK® II

Profiled Steel Sheeting to British,Part B - Composite Slabs”, BHPResearch Report No. BHPR/ENG/R/92/087/PS641Q, October, 1992.

(3) Bennetts ID, Proe DJ, Patrick Mand Poon SL, “Design of Floors withLYSAGHT BONDEK® II Profiled SteelSheeting to British Standards, Part C- Fire Resistance”, BHP ResearchReport No. BHPR/ENG/R/92/088/PS641QP, October, 1992.

Design Manuals

The following BHP Design Manualshave been written for the use ofLYSAGHT BONDEK® II profiled steelsheeting in masonry wall and steel-frame construction:

(a) Formwork Design & InstallationManual

The Formwork Design Manualprovides engineers and builderswith Temporary Propping Tables fora wide range of design solutions,and can be readily used to minimizebare metal thickness and proppingrequirements. The maximumdeflection of the sheeting under wetconcrete may be chosen accordingto whether or not the slab soffit isexposed to view after construction,and is given as part of each designsolution. Tables are given forimposed storage loads of 4 kPa.

In the Installation Manual, designersare provided with essential practicalinformation concerning constructionof LYSAGHT BONDEK® II compositeslabs. The topics covered in themanual include: sheeting installationand propping; detailing fordurability; reinforcement placement;concreting and prop removal; soffitand edge finishing; and installationof profile accessories to supportsuspended ceilings and services.

(b) Composite Slab Design Manual

The complete set of design rules fornormal temperature conditions ispresented. Reinforcement selectiontables are presented for a widerange of design solutions, and canbe used to minimize thereinforcement requirements ofpositive and negative momentregions of either simply-supportedor continuous slabs, noting thatpositive tensile reinforcement (in theform of deformed bars or welded-wire fabric) is only necessary whendesigning for fire resistance.Different incremental deflectionlimits may be satisfied on whetherthe non-structural elements beingsupported are brittle or non-brittle.

Computer Software

Computer software has been writtento produce the solutions in thetemporary propping tables in theFormwork Design Manual and in thereinforcement selection tables in theComposite Slab Design Manual. Theprogram names are as follows:

BIISPAN - formwork design inaccordance with reference (1)BIISLAB - composite slab design inaccordance with reference (2)BIIFIRE - design for fire resistance inaccordance with reference (3)


Program BIISLAB is included as Part3 of the composite slab designmanual. Programs BIISPAN andBIIFIRE are kept as in-housesoftware for use by staff of theMarketing Department of BHP SteelLysaght (S) Pte Ltd who should becontacted when designs outside thescope of the temporary proppingand reinforcement selection tablesare required.

I. FORMWORK DESIGN MANUAL

DESIGN OF STRUCTURALFORMWORK

GENERAL DESIGN PRINCIPLES

Comprehensive design rules havebeen developed for the design ofLYSAGHT BONDEK® II profiled steelsheeting acting as structuralformwork in masonry wall and steelframe construction.

The rules were developed at BHPResearch - Melbourne Laboratoriesand based on the results ofextensive structural testing ofLYSAGHT BONDEK® II sheeting insingle and multiple spanarrangements performed inaccordance with British Standard BS5950: Part 4: 1982 “Structural Use ofSteelwork in Building - Code ofPractice for Design of Floors withProfiled Steel Sheeting”. Bothuniformly-distributed andconcentrated loading situationswere simulated in the tests.

CONDITIONS OF APPLICATION

The temporary propping tables maybe used to detail LYSAGHT BONDEK®

II profile steel sheeting acting asstructural formwork provided thefollowing conditions are satisfied.

1. The support lines extend acrossthe full width of the sheeting andhave a minimum bearing of 50mm atthe ends of the sheets, and 100mmat intermediate supports over whichthe sheeting is continuous.

2. The sheets continue over eachslab span length without anyintermediate splicing or joining.

3. The ratio of the longer slab spanL1 to the shorter slab LS of any twoadjacent spans does not exceed 1.2,i.e. L1 /LS <= 1.2

4. The slab has a uniform cross-section.

5. The supports are effectively rigidsuch that their vertical deflectionduring the construction phase canbe ignored in design.

FORMWORK DESIGN PARAM-ETERS

The temporary propping tables havebeen compiled using the range ofvalues of the design parametersdefined in this Section.

BONDEK II PROFILE

The nominal dimensions of LYSAGHT

BONDEK® II profiled steel sheetingare shown in Fig. 1. In theassembled state, the profilecomprises two intermediate dovetailribs for every interlocking side-lapjoint. The assembled ribs are allboldly embossed along theirexposed top faces and the nominalheight of the embossments is 2 mm.

FIG.1


MATERIAL SPECIFICATION

LYSAGHT BONDEK® II profiled steelsheeting is roll-formed from hot-dipped, zinc-coated, chromate-passivated, high-strength grade BHPSteel ZINC HI-TEN® steel strip inbare metal thicknesses of either 0.75or 1.00 mm. The steel strip has aspecified tensile strength Remin. of550 MPa which conforms to both BSEN 10147 and AS 1397. Theminimum coating class is Z200 formild exposure conditions (e.g.internal floors in a non-aggressiveenvironment), while heavier coatingclasses or painting must be specifiedin moderate or severe exposureconditions (see Rule 28 of Part I).However, Z275 coating class is beingsupplied in local environment.

DEFLECTION LIMITS

The British Standardrecommended(BS 5950:Part 4: 1994)that in general the sheetingdeflection should not exceed L/130(but < 30mm) under its ownweight plus the weight of wetconcrete (including reinforcement)provided ponding is taken intoaccount. In this publication,deflection limits of L/130 is adopted.

LOADING PARAMETERS

1. Sheeting dead load Gdp is takenas 0.13 tbm Kpa

BONDEK® II UNIT WEIGHT

0.75mm Bondek II 10.3 Kg/m2

1.00mm Bondek II 13.6 Kg/m2

2. Concrete dead load Gdc fornormal weight concrete includes anallowance for the weight ofadditional concrete due to sheeting

Construction Design Case Sheeting Concrete Imposed ImposedStage Dead Load Dead Load Construction Storage

Gdp Gdc Loads Qc Loads Qs

(see Note 1) (see Note 2) (see Note 3)

la Strength 1.4 - 1.6 -

lb Strength 1.4 - - 1.6

lla Strength 1.4 1.4 1.6 -

llb Deflection 1.0 1.0 - -

Notes:

1 Construction Stage l is defined a being prior to the placement of concrete, and Construction Stage

ll as during the placement of concrete up until the concrete hardens.

2 Gdc includes an allowance for concrete ponding and the weight of steel reinforcement

3 Both distributed and line load cases must be considered separately.

deflection and for the weight ofsteel reinforcement.

3. Basic Construction loads Qc

(BS5950:Part 4: Cl2.2.3.1)

The basic construction loads Qc

is taken as not less than 1.5 kPa inaddition to the normal dead load.For span less than 3 m, the basicconstruction load should beincreased to not less than 4.5/L kPa.

4. Storage Load Qs (BS5950:Part 4:Cl2.2.3.1)

The provision of 4 kPa is made inthe formwork design. As it iscommon practice to store buildingmaterial on erected sheeting priorto concreting, this provision is amust to ensure safety of sheeting.

5. Load Combination

The basic load combination forthe construction stage are referredto in BS 5950: Part 4: Table 1 and istabulated below:

TABLE 1 - Factored Load Combinations for strength and Deflection Calculations


SLAB GEOMETRY

Minimum Nominal overall depth Dsis taken as 105 mm (BS 5950:Part4:Cl 3.3.5) in this publication, overallslab thickness up to 200 mm isconsidered.

The span-to-depth ratio L/D forcomposite slab using normal weightconcrete tabulated in the followingtable. (Cl 6.6.3)

Span-To-Depth

Ratio L/Ds

Simply-Supported Slab 15 ≤ L/D ≤ 35

Continuous Slab 15 ≤ L/D ≤ 40

In addition, for continuous slab, it isrequired that the ratio of the longerto the shorter of any two adjacentspans should not exceed 1.2

TABLE 1 SPANNING TABLE

TABLE 2 SPANNING TABLE

II. INSTALLATION MANUAL

GENERAL INFORMATION

AVAILABLE LENGTHS The sheets arereadily available custom-cut in anylength from 600 mm up to 12000 mm(Length Tolerance +0, -10 mm).Lengths greater than 12000 mmrequire suitable transportation andon-site handling facilities, and thehours of transportation may berestricted by law.

For speed of installation, LYSAGHT

BONDEK® II sheeting should generallybe used in lengths covering multiplespans (handling weight permitting).

FIRE RESISTANCELYSAGHT BONDEK® II composite slabscan obtain a fire resistance level(FRL) to the requirements of theBritish Standard BS 5950: Part 8. Formore details please contact BHPSteel Lysaght (S) Pte Ltd (MarketingDepartment).

CORROSION PROTECTIONZinc-coated LYSAGHT BONDEK® II

profiled sheeting will provide longand trouble free life withoutadditional corrosion protection inthe following applications:

• Where building, or underside ofthe slab, is fully enclosed or partlyexposed for brief periods,

• elevated exposed slabs withadequate under-floor ventilation incommercial, rural andurban areas in arid climatic zones.

Where the exposed underside ofLYSAGHT BONDEK® II profiled steelsheeting is subjected to a moresevere corrosive environment (suchas industrial, coastal and tropical ortemperate climatic zones), a suitablecorrosion protection system shouldbe chosen to match. Suggested zinccorrosion protection systems forLYSAGHT BONDEK® II sheeting indifferent exposure classificationsmay be obtained at BHP office.

tbm = 1.00mm

Deflection Limit = L/130

MAXIMUM SPAN (mm)

SLAB THICKNESS (MM) 105 110 115 120 125 130 135 140 145 150 155 160 165 170 180 190 200

MAX. UNPROPPED SPAN 3220 3170 3120 3080 3040 3000 2960 2920 2890 2860 2830 2800 2770 2740 2690 2640 2600

tbm = 0.75mm

Deflection Limit = L/130

MAXIMUM SPAN (mm)

SLAB THICKNESS (MM) 105 110 115 120 125 130 135 140 145 150 155 160 165 170 180 190 200

MAX. UNPROPPED SPAN 2730 2730 2730 2730 2680 2650 2610 2570 2540 2500 2470 2440 2410 2380 2330 2280 2230


SAFETYTHE LYSAGHT BONDEK® II sheetinghas bold embossments along thetop of the exposed ribs. Theseembossments enhance safety byreducing the likelihood of workersslipping on the sheets. The LYSAGHT

BONDEK® II is also provided withknurling on the upper face of theflutes, which provides even furtherenhancement of safety againstslippage.

Safety is also provided to personnelworking on the floor below byproviding a covering and byminimizing the obstruction causedby props.

STORING ON-SITELYSAGHT BONDEK® II profiled steelsheeting is delivered in strappedbundles. If not required forimmediate use, sheets or bundlesshould be neatly stacked clear of theground. When stacked, they shouldbe on a slight slope to allowdrainage of water should wettingoccur prior to use.

The sheets or bundles should not beleft exposed in the open forextended periods. If unavoidable,then they should be protected fromrain and moisture with waterproofcovers.

PROPPINGDepending upon the span of theLYSAGHT BONDEK® II compositeslab, temporary lines of support (orpropping) located between the slabsupports may be required. Thissupport will need to be kept inplace during the laying of theLYSAGHT BONDEK® II sheeting, theconcrete placement and until theconcrete has achieved sufficientstrength to support the loads.Detailed information on span ofLYSAGHT BONDEK® II sheetsbetween lines of support may beobtained from Table 1 to 4, Section IFormwork Design.

LYSAGHT BONDEK® II sheeting isnormally placed directly uponprepared propping and thepropping shall support the LYSAGHT

BONDEK® II sheeting across its fullwidth.

Propping generally consists ofsubstantial timber or steel bearers(minimum bearer width 100 mm isrequired) supported by verticalprops installed to preventsettlement during the placementand curing of concrete.

Notwithstanding the requirementfor minimum bearing, where theunderside of the LYSAGHT BONDEK®

II sheeting is featured as the finishedceiling, the use of wide form plystrips attached to the bearers willminimize bearer marks. The width ofthe form ply strips will depend uponthe slab depth, sheeting thicknessand spans. Form ply strips of 300mm width have been successfullyused.

For the design of propping, pleaserefer to Section I of this manual.

CUTTINGCutting of LYSAGHT BONDEK® II

sheets is sometimes necessary totrim sheet sides or to cut sheet endsaround projections such as columnsand stairways.

LYSAGHT BONDEK® II sheets may bereadily cut using a power saw fittedwith an abrasive disc or metalcutting blade.

For cutting, it is suggested that thesheeting be initially laid “ribs down”and cut through the pans and partthrough the ribs. The sheeting couldthen be turned over and the cuttingof the ribs completed.


LAYINGLYSAGHT BONDEK® II profiled steelsheeting must be laid with thesheeting ribs aligned in the directionof the spans.

Where LYSAGHT BONDEK® II sheetsare laid to form a continuousplatform, the following details mustbe observed (refer to Figure 2):

• The slab supports must beprepared for bearing and slip jointsas required.

• LYSAGHT BONDEK® II sheets mustcontinue over each slab spanwithout any intermediate splicing orjointing.

• LYSAGHT BONDEK® II sheets mustbe laid end to end and the jointgenerally centralized at the slabsupports. Where jointing material isrequired, the sheets may be buttedagainst the jointing material.

• LYSAGHT BONDEK® II sheets mustbe supported across the full width atthe slab support lines and thetemporary support lines (propping).

• The end and edges of theLYSAGHT BONDEK® II sheets must beprovided with a suitable edgetreatment in exposed applications toprevent entry of moisture.

• A minimum bearing is requiredfor supports to carry the wetconcrete and construction loads.The minimum bearing is 50 mm forends of LYSAGHT BONDEK® II sheetsand 100 mm for intermediatesupports over which the sheeting iscontinuous.

The LYSAGHT BONDEK® II sheetingmust be assembled with the side lapribs interlocking. Interlocking can beachieved by two methods asdescribed below. However, eithermethod may be used in mostsituations. Variations to thesemethods may be acceptable.

FIG.2


One method of achieving theinterlocking is to progressively lay theLYSAGHT BONDEK® II sheets parallelwith the previous sheet. The femalelap rib is placed overlapping themale lap rib of the previous sheetand interlocking is achieved byapplying foot pressure, or light kick,to the female lap rib to clip onto, and

interlock with, the male lap rib.Interlocking should be doneprogressively as each sheet is laiddown (see Figure 3).

An alternative method requires thefemale lap rib to be placed down atan angle to overlap the male lap ribof the previous sheet. The angled

sheet is then simply lowered downthrough an arc to rest adjacent tothe previous sheet (see Figure 4).

The lap ribs should thus be properlyinterlocked. Where this does notoccur due to some damage ordistortion from site handling orconstruction practices, then it isrecommended that sufficient sidelap fasteners be used to pull thelaps tightly together.

FIG.4

FIG.3


ACCESSORIES

LYSAGHT BONDEK® II accessoriesinclude: BONWEDGE, BON-NUT,

CEILING SUSPENSION NUT, EDGE

FORM, BONFILL AND BONSTRIP, eachof which simplify the construction ofLYSAGHT BONDEK® II composite slaband the installation of ceilings andservices. Please note that except forthe EDGE FORM, these accessoriesare available on a project to projectbasis only.

BONWEDGE A lightweight, pressedmetal, wedge-shaped bracket whichis inserted from below into theLYSAGHT BONDEK® II ribs and lockedinto place in the profiled rib tosupport rods, wires or hangerswhich carry suspended ceilings orservices, other than fire sprinklersystems (see Figure 5).

BON-NUT A heavy duty square nutadhered to a paper strip to alloweasy insertion from below into theLYSAGHT BONDEK® II ribs. Threadedrods may then be screwed into theBON-NUT and locked into position.Available in three convenient threadsizes (M8, M10 and M12), BON-NUTmay be used to support threadedrods for various services andsuspended ceilings (see Figure 6).

FIG.5

FIG.6


CEILING SUSPENSION NUT Alightweight pressed metal, wedge-shaped suspension nut which isinserted from below and locks intothe profiled rib of the LYSAGHT

BONDEK® II Used to support M6threaded rods for suspended ceilingand services other than firesprinkler systems (see Figure 7).

EDGE FORM A galvanized profiledsteel edge formwork. It is availablein any stock sizes to suit commonlyused slab depths not exceeding 200mm, and standard stock length is3000 mm (see Figure 8). Pre-paintedfinish and other zinc coatingthicknesses may also be obtainedfor special applications.

BONFILL A rib infill made ofpolystyrene foam, available in astandard stock length of 1200 mm.It is used to reduce concreteseepage and to reduce air flowthrough the ribs at walls whichsupport the LYSAGHT BONDEK® II

slab (see Figure 9).

FIG.7

FIG.8

FIG.9


BONSTRIP A long plastic insertwhich snaps into and seals the gapof the dove-tail rib. Available in astandard stock length of 3000 mm,it is used in exposed soffits wheregaps need to be covered to providea uniform exposed ceiling line (seeFigure 10).

INSTALLING ON STEEL FRAME

LYSAGHT BONDEK® II profiled steelsheeting may be installed directlyupon the erected structuralsteelwork.

The sheeting may be secured to thestructural steel slab supports whererequired using spot welds orfasteners such as drive nails and self-drilling tapping screws.

Where a movement joint is detailedat a slab support, the sheeting must

not be continuous over this support.The end of one sheet may besecured to the support, the end ofthe abutting sheet must not besecured to allow for movement ofthe composite slab to take place(see Figure 11).

FIG.11

FIG.10


The locations of the securing points(fasteners and spot welds) are to bein the flat areas of the pans adjacentto the ribs or between the flutes.The frequency of securing points toprovide uplift resistance or lateralrestraint will be dependent uponwind or seismic load conditions andaccepted building practice. Forinformation on the frequency, typeand size of securing systems adviceshould be obtained from apracticing structural engineer.

One securing system which hasbeen successfully utilized isdescribed below. However, thefrequency of the securing pointsmay need to be altered to suit theconditions on the project.

• Securing points adjacent toevery rib at the end of sheets andadjacent to the female rib of theside lap at each intermediate slabsupport over which the sheeting iscontinuous (see Figure 11).

• Secure LYSAGHT BONDEK® II withdrive nails, self-drilling tappingscrews or spot welds.

• Drive nails should be powder-activated steel mails 4 mm nominaldiameter, suitable for structural steelof 4 mm or greater flange thickness.

• Self-drilling, tapping screwsshould be No. 12 - 24 x 32 mm hexhead, suitable for structural steel upto 12 mm flange thickness: forstructural steel greater than 12 mmflange thickness, then pre-drillingwill be necessary with the use No.12 - 24 x 32 mm hex-head threadforming screws.

• Spot welds should be 12 mmdiameter, made with 3.25 mmdiameter cellulose, iron powder AD/DC high penetration electrodes.When welding, suitable safetyprecautions should be takenregarding fumes given off duringwelding of zinc coated products.Surfaces to be welded must be freeof loose material and foreign matter.Where the LYSAGHT BONDEK® II

soffit or the structural steelwork hasa pre-painted surface, securingmethods other than welding may bemore appropriate.

In projects of composite beamconstruction, the LYSAGHT BONDEK®

II sheeting must be fastened in eachpan at each compositely designedsteel beam.

In some projects of composite beamconstruction where stud weldingthrough the sheet has beenspecified, the stud welding has beenconsidered to be a suitable securingmethod for the sheeting, howeversome preliminary fixing by one ofthe methods mentioned above isnecessary to secure sheeting priorto the commencement of studwelding. Stud welding must bebetween pan flutes for sheetstransverse to beams to ensure thereis no gap between mating surfaces.


FASTENING SIDE LAP JOINT

To maintain a stable platform underload, and to minimize concreteseepage during pouring, the sidelap joints may require fastening.Fasteners shall be No. 12 - 24 x 20mm self-drilling tapping screws andbe located on the side lap ribmidway between embossments(see Figure 12). The frequency offasteners will depend upon thesituation as described below:

• The minimum fastenerrequirement is one fastener at mid-span for support spacing of 2750mm or greater.

• To obtain a point load rating of2.3 KN (235 kg), the side lap jointswill require fastening for supportlines spaced over 2000 mm. For 1.0BMT LYSAGHT BONDEK® II, a singlefixing at mid-span is required up toa maximum of 3250 mm spacingbetween supports. For 0.75LYSAGHT BONDEK® II, two fixings atthird points are required up to amaximum of 2400 mm spacingbetween supports.

• For exposed LYSAGHT BONDEK®

II soffits where good visual quality isrequired, it may be necessary toprovide fasteners at closer spacingto ensure a uniform soffit betweenadjoining sheets, and to furtherreduce concrete seepage.

CUTTING AND FITTING EDGEFORM

Edge Form is a simple, strong,lightweight, easy to use edge form.Edge Form simplifies the installationof most LYSAGHT BONDEK® II slabs,neatly retaining the concrete. EdgeForm is easily fastened to theLYSAGHT BONDEK® II sheeting andprovides a smooth top edge forquick and accurate screeding.

Edge Form should be made of thesame material as LYSAGHT BONDEK®

II. Edge Form is easily spliced andbent to form internal and externalcorners of any angle and should befitted and fully fastened as thesheets are installed.

FIG.12

12 - 24x20mm


The Edge Form must be fastened tothe underside of unsupportedpanels every 300 mm. The topflange of Edge Form must be tied tothe ribs every 600 mm with buildersstrapping (see Figure 13).

No. 10 - 24 x 16 mm self-drilling,tapping screws or similar fastenersshould be used for all fastening.

SEALING

Seepage of water or fine concreteslurry can be minimized by followingaccepted construction practices. Thefollowing is provided as a guideonly.

The gap between abutting LYSAGHT

BONDEK® II sheets may be sealedusing a waterproof tape (see Figure14). Alternatively, by sandwichingcontraction joint material betweenthe butting ends of sheeting,seepage would be minimized.

FIG.13

LYSAGHT BONDEK® II sheeting endswhich abut Edge Form may be moreeffectively sealed with waterprooftapes as above, but in any case withthe minimum bearing requirementthe concrete seepage would beminimized.

Side laps of LYSAGHT BONDEK® II

sheeting must be fastened asrecommended on pg. 15 - FasteningSide Lap Joints in order to minimizethe concrete seepage.


FIG.14

HOLING

LYSAGHT BONDEK® II profiled steelsheets act as longitudinal tensilereinforcement as per conventionalbar or fabric reinforcement inreinforced concrete slabs. Holing ofLYSAGHT BONDEK® II sheets toaccommodate pipes and ducts wouldreduce the effective area of steel.

Acceptable regions for holing are asfollows, however the size andquantity of holing must be on theapproval of the design engineersince the extent of holing, and theaccompanying reduction in area ofconcrete, may affect the slabperformance (refer to Figure 15).

Where there is a sizable gapbetween the end of the LYSAGHT

BONDEK® II sheet and adjoiningEdge Form or adjoining LYSAGHT

BONDEK® II sheet, it may benecessary to provide a support forthe overlaying waterproof tapes.BONFILL may be used for thissupport (see Figure 14).Alternatively, the ends of the ribscan be taped off individually.

There are various commonly usedwater proof tapes with qualitiessuitable for the application.Reference to the manufacturer ofsuch tapes should be made fordetails.

• Keep within a length of 0.1 xclear span from an interior supportof the slab for slabs designed as acontinuous slab.

• Holes should be placed in thecentral span of any sheet with aminimum edge distance of 15 mmfrom the rib gap.

• Holes should be circular with amaximum of 150 mm in diameter.

• Holes must be cut using asuitable drill or hole saw.

• Cutting of LYSAGHT BONDEK® II

sheeting should be carried out afterthe concrete has cured. This willrequire accurate location of ductingoutlets (e.g. electrical outlets) duringformworking. Small pilot holesdrilled through the LYSAGHT

BONDEK® II prior to concreting couldbe used. The pilot holes should betaped to prevent concrete seepage.

For holes outside the abovelimitations, advice is available fromBHP Steel Lysaght Singapore Pte Ltdor from a practicing structuralengineer.

FIG.15


INSPECTION

Inspection of the installed sheetingby the relevant site supervisor isrecommended at regular intervals ofinstallation to ensure that thesheeting has been installed inaccordance with this publication andwith accepted building practice.

REINFORCEMENT

GENERAL

LYSAGHT BONDEK® II profiled steelsheeting is capable of withstandingtemporary construction loadsincluding the mass of workmen,equipment and materials all inaccordance with BS 5950: Part 4:1982 (refer to Section I).

However, it is good constructionpractice to ensure protection fromconcentrated loads, such asbarrows, by use of some means suchas planks and/or boards.

LYSAGHT BONDEK® II sheeting actsas longitudinal tensile reinforcementand should be treated as such. Thecondition of the sheeting should beinspected before the concrete ispoured.

Reinforcement in slabs is required tocarry and distribute the design loadsand to control cracking.Reinforcement is generally detailedas transverse and longitudinal inrelation to span, but otherreinforcement required for trimming

may be positioned in otherorientations. Refer to Figure 18 for atypical cross-section of a LYSAGHT

BONDEK® II composite slab andterms associated with the placementof reinforcement.

Reinforcement must be properlypositioned, lapped where necessaryto ensure continuity, and tied toprevent displacement duringconstruction. Fixing ofreinforcement is to be in accordancewith BS-8110: Part 1.

The uppermost layer ofreinforcement must be positionedand tied to prevent displacementduring construction to obtain thespecified minimum concrete cover(refer to BHP Steel Composite SlabDesign Manual for guide to therecommended concrete cover).

For movement joints, thereinforcement is stopped short oneither side of the joint to permitmovement of the adjoining slabs.

Where fabric (such as BRC Mesh) isto be used in thin slabs or wherefabric is used to act as bothlongitudinal and transversereinforcement, particular attentionshould be taken to ensure thespecified minimum concrete coverand the required designreinforcement depth are maintainedat the splices. To assist in thismatter, it is prudent to use splicebars.

Fixing of reinforcement using chairsand spacers must be such that thechairs and spacers are placed uponthe pan area. Depending upon thechair type used and the load theycarry, it may be necessary to useplates underneath the chairs toalleviate depressions in theLYSAGHT BONDEK® II sheeting,particularly where the soffit will beexposed. Transverse reinforcementmay be utilized as spacers orsupports for longitudinalreinforcement.

TRANSVERSE REINFORCEMENT

Transverse reinforcement ispositioned across the ribs of theLYSAGHT BONDEK® II profiled steelsheeting. Transverse reinforcementmay be detailed as deformed bar orfabric reinforcement. In mostapplications, the transversereinforcement is for the crackcontrol due to shrinkage andtemperature effects. Transversereinforcement for large holes is usedto distribute loads into adjacentstrips of composite slabs.

To control flexural cracking in thetop face of the slab, transversereinforcement in the top-face maybe detailed over walls or beams,which run in the same direction asthe LYSAGHT BONDEK® II sheets.

For ease of construction,reinforcement for control of crackingdue to shrinkage and temperatureeffects is generally fabricreinforcement.


Unless otherwise specified, thebottom-face transversereinforcement for control of crackingdue to shrinkage and temperatureeffects should be placed directly ontop of the ribs of LYSAGHT BONDEK®

II profiled steel sheeting forunexposed slabs not exceeding 200mm in depth, otherwise instructionfrom the design engineer will berequired.

LONGITUDINAL REINFORCEMENT

Longitudinal reinforcement ispositioned in the same direction asthe ribs of the LYSAGHT BONDEK® II

profiled steel sheeting. Longitudinalreinforcement may be detailed asdeformed bars or fabricreinforcement.

Longitudinal reinforcement ispositioned to carry design loads andis located in the top and bottomfaces of the slab.

Top-face longitudinal reinforcementis located over interior supports ofthe slabs and extends intoapproximately a third of theadjoining spans, or as detailed bythe structural engineer. For designinformation refer to BHPCOMPOSITE SLAB DESIGNMANUAL. For single spans, top-facelongitudinal reinforcement is notnormally detailed.

Bottom-face longitudinalreinforcement is located betweensupports of the slab but dependingupon the detailing over the interiorsupports, it may be continuous,lapped or discontinuous. Bottom-face longitudinal reinforcement maybe placed on top or belowtransverse reinforcement.

Location of bottom-face longitudinalreinforcement in elevatedtemperature conditions requiresspecial detailing. Generally, this willrequire the bottom-face longitudinalreinforcement to be kept a minimumdistance away from the ribs andsoffit of the LYSAGHT BONDEK® II

sheeting. Refer to BHP SteelCOMPOSITE SLAB DESIGNMANUAL for more information.

TRIMMERS

Trimmers are used to distribute thedesign loads to the structuralportion of the slab and/or to controlcracking of the concrete atpenetrations, fittings and re-entrantcorners.

Trimmers may be either deformedbars or fabric reinforcement and instraight lengths or shaped. Thetrimmers may be detailed orspecified to be laid at angles. Thetrimmer reinforcement is generallydetailed between the top andbottom layers of transverse andlongitudinal reinforcement.

Fixing of trimmers is generally withties from the top and bottom layersof reinforcement.

FINISHING

SOFFIT AND EDGE FORM FINISHES

For many applications, the LYSAGHT

BONDEK® II profiled steel sheetingprovides an attractive appearance tothe underside (or soffit) of acomposite slab and will provide asatisfactory ceiling. For example, incar parks, under-house storage andgarages, industrial floors and thelike. Similarly, the Edge Form willform a suitable edging. In suchapplications, a cleaning of theexposed surfaces may be required(see Table 3 for cleaningpreparations).

TABLE 3: BONDEK II Soffit and Edge Form Preparation

SOFFIT AND EDGE FORM TYPE PREPARATION

Galvanized soffit or edge • Light corrosion marks indicated by white to greystaining due to wet bundles may be removed witha kerosene rag.

• Grease or oil deposits may be removed with akerosene rag. For stubborn deposits, use paintthinners.

• Concrete seepage marks and dirt to be removed bywashing as described above.


Where the LYSAGHT BONDEK® II soffitis to be the ceiling, then care shouldbe taken during construction tominimize propping marks (refer to Pg.8 - Propping) and to provide auniform surface at the side laps (referto Pg. 15 - Fastening Side Lap Joints).

FIRE SPRAYS

Where a building is beingrefurbished and due to a change ofoccupancy, the fire resistance of theLYSAGHT BONDEK® II compositeslabs may need to be increased. Thismay be achieved by the addition ofa suitable fire-protection material tothe underside of the slabs.

The addition of such materials to theunderside of the slab will increase thefire-resistance of the slab with respectto insulation, integrity and structuraladequacy. In the case of fire spraymaterials, the presence of theLYSAGHT BONDEK® II open ribs willprovide a positive key to keep the firespray in position throughout a fire.

SUSPENDED SERVICES

Services such as fire sprinklersystems, piping and ducting areeasily suspended from LYSAGHT

BONDEK® II slabs using BON-NUTsuspension nuts (see Figure 17).Ceiling Suspension Nuts orBONWEDGE suspension bracketsare suitable for services other thanfire sprinkler systems.

Threaded rods are then used tosupport the services. Loadcapacities and threaded rod size forthese accessories need to beconsidered when making a selectionfor the particular service.

For details regarding thepreparation of soffit, application andthickness of materials to be appliedfor various situations, refer to themanufacturer of the fire protectivematerial.

SUSPENDED CEILINGS ANDSERVICES

SUSPENDED CEILING

Ceilings are easily suspended fromLYSAGHT BONDEK® II slabs usingCeiling Suspension Nuts, BON-NUTsuspension nuts, or BONWEDGEsuspension brackets. Threaded rodsor wire hangers are then used tosupport the ceiling. Alternatively,hangers may be attached to eyeletpins powder driven into theunderside of the slab, or to pigtailhangers inserted through pilot holesin the LYSAGHT BONDEK® II sheetingbefore concreting (see Figure 16).

FIG.16

FIG.17


Typical Steel Framing Plan

FIG.18


Details Incorporating BONDEK® II

DETAIL 1-1

DETAIL 2-2

DETAIL 3-3

DETAIL 4-4

DETAIL 5-5

DETAIL 6-6


Documents

Bondek II