site testing - vol1 - revised - aefac · 2020. 4. 15. · these guidelines have been based on...

SITE TESTING GUIDELINES VOL 1: GENERAL

Ver.1.1January2020

TECHNICAL NOTE

AEFAC-TN05

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TECHNICAL NOTE: SITE TESTING GUIDELINES – VOL 1: GENERAL

www.aefac.org.au

Preface ThisTechnicalNote isVolume1ofa suiteofAEFACTechnicalNotesdedicated toprovidingbestpracticerecommendationsforsitetestingofpost-installedfasteners.Therecommendationsareintendedtoassistdesignengineersformulateappropriatesite testing procedures and to assist field testers conducting on site testing. It isassumedthatthetesterissuitablyexperiencedandcompetentattestingfasteners.

Thefullseriesofthe“SiteTestingGuidelines”TechnicalNotesisasfollows:

• Volume1:General• Volume2:Prooftests• Volume3:Ultimatetests• Volume4:Testinginmasonry

ItisarequirementthatVolume1beusedinconjunctionwiththeothervolumesasnecessary.

TheseguidelineshavebeenbasedonrecommendationsmadeinBS8539:2012[1]andbytheConstructionFixingsAssociation[2].

Note: Site testing only show the short-term performance of fasteners for thetemperatureandenvironmentalconditionspresentduringthetests.TheperformanceandsuitabilityoftheproductshallbereviewedandcheckedfromtheissuedETAfortheexposure conditions such as temperature and environmental effects to the fastenerduringitslifetime.

1. Scope The test methods outlined in these Technical Notes relate to quasi-static loadingproceduresforproduct-specificevaluationperformedonsite.TheseTechnicalNotesapplyforpost-installedfastenersonly.Theadviceprovidedinthisdocumentisofageneralnatureandisconsistentwithinternationalguidelines([1],[2]).Thisguidancedocument should not be considered a substitute for manufacturer’s installationinstructionsortechnicaladvicefromthefastenermanufacturer/supplier.

Incorrect or incomplete site testing practice may result in a failure to diagnosedeficientinstallationorthecorrectperformanceofafastener,leadingtocatastrophicoutcomes.

TheseTechnicalNotesdonotcoverthetestsinsheardirection,astheyarelimitedbymaterialstrengthofbasematerialandfastener,andlesssensitivetoinstallation.Inaddition, compressive actions are normally transferred from the fixture into thesubstratewithlittleornoeffectonthefastener.Thus,thecompressiveactionsare

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excluded in the TechnicalNotes. This document provides advice primarily on thetensile resistance of fasteners for applying Proof or Ultimate Loads in tensiledirection

This document provides technical advice on site testing techniques to verify theperformanceoffastenersanddoesnotaddressallsafety-precautionsneedingtobefollowedduringsitetestingoffastenerstoconcreteandmasonry.AdviceshouldbesoughtfromtherelevantsafetyauthoritysuchasWorkCoverAuthorityandthesitemanagerforadviceontheuseofPersonalProtectiveEquipment(PPE)duringtesting.

Note:AsaminimumPPEforthetestershouldincludeahelmet,eyeprotection,gloves(if handling chemical fasteners), dustmask (if exposed to dust in a confined space),hearing protection, and equipment to restrain the test setup during testing (ifnecessary).

2. Notation fy = Characteristicyieldstrengthofsteel(fastener)

FOS = FactorofSafety

As = Crosssectionalareaofsteel(fastener)intension

hef = effectiveembedmentdepthoffastener

κP,test =proofloadtestfactordependingonthepercentageoffastenerstestedinadiscretearea

ks = statisticalsamplingfactor

Np = loadappliedtofixingforaproofloadtest

Np,max =maximumallowableloadappliedtofixingforaproofloadtestwithoutdamagingfastening

Ntest =maximumloadappliedtofixtureduringtestingtodetermineallowableresistancebasedonthesimplifiedmethod

NRd = designresistanceofthefastening

NRk = characteristicresistanceofafastening

NR,all = allowableresistanceofthefastening

NRk,ETA =characteristicresistanceofthefasteningpublishedintheapprovaldocument(ETA)

NRk1 =characteristicultimateloaddeterminedfromtestsonprequalifiedproducts

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NRk2 =characteristicultimateloaddeterminedfromsimplifiedtestsinthemasonry

NSk = Characteristicactionappliedtofastener

Nu = ultimatestrengthofafastening

Nu,ave = averageultimatestrengthofasampleoffastenings

Nu,low = lowestultimatestrengthfromasamplepopulationoffastenings

N1mm = loadat1mmdisplacementforasinglefastener

N1mm,ave =averageloadat1mmdisplacementforasamplepopulationoffasteners

S* = designload

s = standarddeviationoftheultimatestrengthofasamplepopulationoffasteners

v = coefficientofvariationoftheultimateloadsdeterminedfromtesting

β =productspecificinfluencingfactorprovidedintheapprovaldocument(ETA)basedonperformancemeasuresdeterminedfromtestingandevaluationinagivensubstrate

γF = partialsafetyfactorforaction,typically1.4forgeneralcase

γM =partialsafetyfactorformaterialpublishedintheapprovaldocument(ETA)

κave =factorusedtodeterminetheallowablestrengthofafixturebasedonaverageultimateloadsdeterminedfromtesting

κlow =factorusedtodeterminetheallowablestrengthofafixturebasedonthelowestultimateloaddeterminedfromtesting

κtest =factorusedtoestablishthetestloadforthesimplifiedapproachfordeterminingtheallowableresistance

φ = capacityreductionfactor

φM =capacityreductionfactorformaterialresistance,inverselyrelatedtothepartialsafetyfactorformaterialstrength(γM)publishedintheapprovaldocument(ETA)

3. Terminology Thefollowingterminologyanddefinitionsareadoptedinthisdocument.AdditionalterminologyanddefinitionsmaybefoundintheAEFACFastenerDictionary[3].

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Allowableresistance:maximumworkingloadderivedfromtestsperformedonsitewhen the proposed fastener is to be used in a base material approved by themanufacturerbutforwhichthereisnorecommendedresistance.

Characteristic resistance: resistance derived as the 5% fractile (95% of fastenersexceed the characteristic resistancewith 90% confidence level) ofmean ultimateresistance.Thisisdeterminedfromtestsorempiricalcalculationsbasedonmodesoffailure.

Confinedtest:atestperformedonaninstalledfastenersuchthatthepositioningofreaction points of the test rig inhibits the formation of concrete-relatedmodes offailure.

Design resistance: resistance derived from the characteristic resistance by theapplicationofcapacityreductionfactor

Fastener:atypeofdevicethatispost-installedintohardenedconcreteorcast intoconcrete.

Fastening:anassemblycomprisingfastener(s)tosecureafixturetotheconcretebasematerial.

Fixture:theelementthatisbeingsecuredtothebasematerialviafasteners.

Manufacturer’s recommended load: maximum working load recommended by amanufacturer,typicallythecharacteristicresistancedividedbypartialsafetyfactorformaterialandaction[NRk/(γM×γF)]

Preliminarytest:testcarriedoutonsitetodeterminetheallowableresistanceinthecasewherenocharacteristicresistanceorrecommendedresistanceisavailable.

Proof tests: a testperformedona completely installed fastenerand is intended tovalidatecorrectinstallation.

Responsibleengineer:thepersonresponsibleforoverseeingthetestregimeforthefastenersand toensure that the site testingof fastenersprovides the informationrequiredfortheproject.

SafeWorkingLoad:See“WorkingLoadLimit”

Tester:thepersonwiththeresponsibilitytoconducttheon-sitefastenertestingtoanagreedregimeandtoreportinformationcollectedduringtesting.

Unconfinedtest:atestperformedonaninstalledfastenersuchthatthepositioningofreactionpointsofthetestrigdoesnotinhibittheformationofanymodesoffailure.

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Ultimateloadtest:Atestperformedonafastenerwhoseinstallationiscompleteandis intendedtoaid inestablishingthesuitabilityofthe fastener inaparticularbasematerial.

Working Load Limit (WLL): the maximum load that can be applied without thestrengthandstabilityrequirementsbeingexceeded.Alsoknownassafeworkingload,allowableworkingload,maximumratedload,andpermissibleworkingload.

4. General Sitetestingmaybeperformedforoneoftworeasons:

(i) Validatecorrectinstallation(prooftests),or(ii) Identifythecharacteristicstrengthofafastenerinagivensubstrate(ultimate

tests).

The performance of fasteners in concrete is typically known, thus ultimate testsgenerallyarenotwarrantedinconcretesubstrates.However,giventhecomplexityofmasonry substrates, technical data is generally limited such that site testing isfrequentlyemployedtodeterminetheultimatestrengthofafixingforuseinmasonrysubstrates.

Sitetestingforprooftestsandultimatetestsrequiresthatthefastenersbeingtestedareinstalledinaccordancewiththemanufacturer’sinstallationinstructions,aswellasanysupplementaryrequirementsstipulatedbytheresponsibleengineer.

Note:Itistheresponsibilityofthetestertoprepareareportofresultsfromthetestsundertaken. Interpretation of the test results from site testing is undertaken by theresponsibleengineer,includingidentifyingcausesofanyfailures,anymodificationstothetestregimeandthemodificationtothespecificationoffasteners(ifrequired).

ThisGuidanceNoteprovidesadviceprimarilyonthetensileresistanceoffastenerssincetheshearstrengthislesssensitivetoinstallationandisgenerallygovernedbymaterialstrengthifsufficientedgedistanceispresent.Shearstrengthmaythereforebereadilydeterminedbycalculatingtheshearcapacityofthefastenercomponentorsubstrate.However,whentherequirededgedistanceislessthanthemanufacturer’spublished edge distance, technical assistance from the manufacturer should besoughttodetermineanappropriatesheartestprogram.Sheartestingmayalsoberequiredtodeterminetheperformanceofafastenerinlowstrengthmasonry.Tensiletestingisnecessarysincethetensileperformanceoffastenersisdependentonthesuitabilityofthefastenerinthesubstrate,properdesignandcorrectinstallation.

FastenerproductshavingaEuropeanTechnicalApproval/Assessment(ETA)publishtheirperformanceforagivensubstratetype,togetherwithotherparametersdefining

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theirperformance[4,10].ThisinformationmaythenbeusedwithdesignprovisionssuchasthoseinAS5216[5]tocalculatetheexpectedstrength.WhenaproductdoeshaveanETA,thedesignengineermayrequestsiteteststobeperformedtoverifythattheproducthasbeeninstalledcorrectly.

Note:Ifsitesheartestsaredeemednecessary,technicaladviceshouldbesoughtfromthesupplierofthefastenerproducttodevelopasuitabletestprocedure.

5. Type of test: proof test vs ultimate test Theengineerresponsibleforrequestingthesitetestsdeterminesthenatureofthetestswhichmayfallintooneoftwocategoriesoutlinedbelow.Therefore,whilethetesterperforms the test inaprescribedmanner, the tester’s roledoesnot includeidentificationofsuitabletestloads,interpretationofresultsorcalculatingallowableloads based on the outcomes of testing [7]. These responsibilities belong to theengineerspecifyingthetest.

5.1. Proof tests

5.1.1. General

The objective of proof tests is to validate installation on a sample population offastenersbyloadingtheinstalledfastenerstoaprescribedtestload(proofload)thatisafractionofthefastener’scapacity.Themagnitudeofthetestloaddependsonthefastenerapplicationandmaterial.Prooftestsshouldbeconductedonasampleofthefasteners installed for the project. A proof load does not result in the fixtureexperiencing failure and is not used to determine the allowable strength of thefastenerinagivensubstrate.

Proof tests are generally short term in nature and are therefore not suitable forinvestigatingcreepbehaviour.Whilethenatureoftheprooftestsprovidesamodestsafetymargin,theyarenotappropriateforinvestigatingthesuitabilityofafastenerinagivensubstrate.

Proof testsmayonlybecarriedoutafter themanufacturer’srecommendedcuringtimeforthechemicalfasteners.

Note:The requirement for proof tests to verify correct installation of safety-criticalfastenersmaynotbe required if the fastenerhasbeenprequalifiedaccording to therelevantEAD/ETAG,andtheinstallerisundersupervisionandisappropriatelytrainedeitherviatheAEFACInstallerCertificationProgramand/ortrainingprovidedbytheproduct supplier.Therequirement forproof testing isdeterminedby theresponsibleengineer.

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5.1.2. Proof test sequence

Therequirementofaprooftestistoloadeachfastenertotheproofloadidentifiedbythedesign engineer todemonstrate that the fastenerhasbeen installed correctly.Uponachievingtheproofload,thetestmaybeterminated.FurtherguidancemaybefoundinVolume2.

5.2. Ultimate tests

5.2.1. General

Theobjectiveofultimatetestsistodeterminetheallowablestrengthofthefastening.Ifultimatetestsarerequired,theyshouldbeperformedpriortocompletionofthefastenerselectionprocesstoensurethatallprojectrequirementsaremet.

Scenarioswhereultimatetestingmaybeperformedareasfollows:

(i) Manufacturerhasaprovisionalapprovalfortheproducttobeusedinthesubstratebutperformancedataisnotavailable.

(ii) Fastener has an approval (e.g. ETA) for use in masonry but the type,strengthordimensionsofthemasonryareoutsidethescopeoftheETA.

(iii) Fastenerhasanapproval(e.g.ETA)buttheapplicationisoutsidethescopeoftheETA,forexampleedgedistanceisoutsidethescopeoftheETA.

The test procedure for applications involving products without an ETA is closelybased on recommendations from BS 8539 [1] and the Construction FixingsAssociation’sguidancenote,“ProcedureforSiteTestingConstructionFixings”[2].

Ultimatetestsarecarriedoutonasamplepopulationofsacrificialfasteningsthatareconsidered to be representative of the intended application. This requires arepresentativesubstrate,thesametypeoffastenersthatwillbeusedintheprojectandinstallationbythesameworkcrew.Itmaybenecessaryfollowingtestingtomakegoodanysubstratedamageincurredbythetestpopulation.

Ultimate tests are not required for fasteners in concrete provided the product isprequalified in accordance with Appendix A of AS 5216 and the application fallswithinthescopeoftheproduct’sapproval.Inthiscasethedesigndataispublishedinthe prequalification. If the fastener is being installed inmasonry that is the samecategoryforwhichithasbeenawardedaprequalification,ultimatetestsmaystillberequiredifeitherthestrengthofthemasonryorthedimensionsofthemasonryarelessthantheminimumrequirementoftheprequalification.Inthecaseofmasonry,thecategoryofsubstraterelatestothetypeormaterialandtypeofbrickunit(e.g.solid,perforated,hollow).

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If the intended application is beyond the scope of its prequalification (approval),ultimate testsmaybeperformed to establish the allowable strengthprovided thefastener manufacturer approves the fastening for use in this specific application.Further guidance is available on the limitations of fasteners installed in concreteapplicationsin[3]andforchemicalfastenersinstalledinmasonryin[6].

Note:Fastenersforultimatetestsareconsideredsacrificialandshouldnotbeusedintheproject.

5.2.2. Ultimate test sequence

There are two types of ultimate test that may be performed depending on therequirementsoftheproject:• Simplifiedregime:Eachfastenerinthesamplepopulationisloadedtoatestload(Ntest)determinedbythedesignerpriortothetesttakingplace.Oncethedesiredload is achieved the load is removed to reduce the likelihood of damaging thesubstrate. The allowable strength of the fastener (NR,all) is calculated byconsidering the maximum test load, average ultimate strength and the lowestultimatestrengthrecordedfromtestsonthesamplepopulation.

• Statisticalregime:Thisregimeisdestructiveandrequireseachspecimenwithinthesamplepopulationtobetestedtofailure.Theallowablestrengthofthefastener(NR,all)iscalculatedusingastatisticalmethodbasedontheultimatestrengthofthesamplepopulation.

FurtherdetailsofthesetworegimesareprovidedinVolume3.

6. Test Setup

6.1. Test equipment Test equipment should be inspected prior to commencement of testing to ensuregoodworkingcondition.Additionalrequirementsforthetestapparatusinclude:• TheWorkingLoadLimitofallcomponentsofthetestapparatus(supportframe,tensionrods,couplers,etc.)shouldnotbe lessthanthetest loads.TheWorkingLoadLimitshouldincludeasuitablesafetymargintoensuretheequipmentisnotdamagedduringtesting.

• Thespecifiedstrokeofhydraulic testequipmentshouldnotbeexceededatanystageduringthetest.

• The accuracy of the load gauge should be +/- 5% of the load readings. Theequipment should be calibrated at least annually, as well if the equipment isdroppedorrepaired.Ifacalibrationrequiresaconversionfromgaugereadingstoactualload,theconversionshouldbeprovidedinthetestreport.Theloadgauge

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shouldbecapableof indicatingthemaximumloadachievedduringthetestthatmaybereferredtouponcompletionofthetest.

• Calibrationshouldoccur inaprecisiontestmachinesuchasonethathasNATAcertification.

• Theaccuracyofdisplacementmeasurementshouldbetowithin+/-0.02mm.Note:Ifitisnecessarytoinstallfastenersforthepurposeoftestingthemanufacturer’sinstallationinstructionsshouldbeconsultedforalistofequipmentnecessaryforcorrectfastenerinstallation.

6.2. Configuration of test rig Thereareavarietyofdifferentsizedtestsetupsavailableforapplyingloadstofixings,includingthosesuitableforlargerfixings(seeFigure2)andthosesuitableforsmallerfixings (seeFigure3).Thesuitabilityof the test rigshouldbeaccounted forwhenconsideringtheprojectrequirements.

Selectionofanappropriatetestrigshouldconsiderthenatureofthetest(prooftestvs.ultimate test)and the typeof fastener (e.g.mechanicalvs. chemical) since thisaffects the potential mode(s) of failure that may be observed. An ultimate testperformed for mechanical or chemical fasteners or a proof test of mechanicalfasteners generally requires an unconfined test setup (refer to Figure 1 (a)) todemonstratethedecisivemodeoffailure.Aconfinedtestsetup(refertoFigure1(b))maybeutilisedforprooftestofchemicalfastenerstoverifythecorrectbondhasbeenachieved between the chemical and steel element or the chemical and substrate.However,itshouldbenotedthataconfinedtestmaynotdetectgrosserrorsrelatedtoincorrectembedmentdepthoffastenersinstalled.Anunconfinedtestsetupwouldbemoreappropriateforcheckingpotentialgrosserrorsinembedmentdepthduringinstallation.

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(a)Unconfinedtestsetup. (b)Confinedtestsetup.

Figure1:Differenttypesoftestsetupthatmayberequiredonsite.

6.2.1. Position of legs of test rig

Regardlessofthesizeoftherig,thelegsshouldbeadjustabletoensurethatdirecttension is applied to the fixing and that shear loads and bending moments areavoided. Proper adjustment of the legs will ensure correct alignment of theapplicationofloadandpropersupportofthelegsofthetestrig.

The proximity of the test apparatus’s legs to the fastener is important and mayinfluencetheresultswhentooclosetothefastenerbysuppressingamodeoffailure(suchasconcreteconefailure).Therecommendedminimumspacingbetweenthetestriglegandthefixingforanunconfinedtest(refertoFigure2andFigure3)dependsonthetypeoftestassummarisedinTable1.

Table1:Minimumrequireddistancebetweenfastenerandsupportlegsoftestrig.

Typeoftest MagnitudeofmaximumloadMinimumdistancebetweenfastenerandsupportlegsof

apparatus

Proof*<1.5xmanufacturer’s

recommendedloadand0.7×steelyieldstrength

0.75hef

Ultimate Determinedfromtest 2.0hef

* Note that for proof tests on chemical fasteners to assess the performance of theinterfacebetweenthefastenerandconcrete,thesupportlegsmaybeveryclosetothefastenertosimulateaconfinedtest.

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Theeffectivedepth(hef)referstothegreatestdepthtowhichloadisresistedbythefixing(fastenerengageswiththeconcrete),notthetotaldepthofthefixingordepthofhole.

If theminimum spacingbetween the fastener and test rig support leg outlined inTable1cannotbeachievedduetorestrictedaccess,theengineerrequestingthetestsshouldbenotifiedinthetestreport.

Figure2:Hydraulicramsetupforlargefixingswithhighload.

Figure3:Handoperatedtestrigforsmallfixingswithlowertestloads.

6.2.2. Stability of test rig

Thestabilityofthetestrigshouldnotbecompromisedatanytimeduringthetestorasaresultofafailureofthefixturebeingtested.Inthecaseofoverheadtests(suchasonthesoffitofaconcreteslab)thetestrigshouldbesecuredsoasthetestriganditsparts/componentswillnotfallintheeventoffailureofthefixing.

6.2.3. Connection of fastener to test equipment

Thefastenershouldbeinstalledinaccordancewiththemanufacturer’sinstallationinstructions. Intheeventthatthefastener is tobetorquedduring installation, thefastenershouldbeinstalledthroughanappropriatelysizedbushandplateassemblywithanappropriateholeclearanceandthicknessaspertheengineer’sspecification.A torque may only be applied to chemical fasteners once manufacturer’srecommendedcuringtimeiscomplete.

The choice of connection between the fixing and the test rig will depend on theobjectiveofthetest.Asimplethreadedcouplermaybeusedwhereaprojectedthread

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isavailable,withorwithoutaplateclampedwithanuttosimulateclamping(refertoFigure5(a)andFigure5(b),respectively).Allnecessaryprecautionsshouldbetakentoensurethetestrigisalignedwiththeorientationofthefastenersoasnottoinducebendingduringtestingthatmayleadtoinvalidresults.

(a)Torquerequiredtoclampplate.

(b) Torque notrequired for fixtureinstallation.

Figure4:Pullingframeforclampingeffect.

Figure5:Couplersattachedtopullingrod.

Forultimateloadtestingthecouplershouldcoveralengthofthreadequaltoatleast1.5timesthediameteroftherodbeingtested.Thechoicebetweenthetwomethods(withorwithoutaclampedplate)willdependonwhetheratorqueisappliedtothefixture during installation. Displacement-controlled fasteners, some undercutfastenersandmostbondedfastenersdonotrequireaninstallationtorquetooperatecorrectly.Conversely,installationtorquefortorque-controlledexpansionfastenersisimperativefortheircorrectoperation.

Figure5depictsanalternatesetupthatmaybeadoptedwhentheclampingeffectisto bemonitored during the test. In this setup the plate simulates the fixture andaccurate displacement measurements may be made on the top of the fastener.Sphericalwashersmaybeusedtoeliminatenegativeeffectsofbending.

6.2.4. Displacement measurement

Characteristicsimportantfordisplacementmeasurementincludingthefollowing:

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i) The accuracy of the displacementmeasurement should not exceed 10% of theactualreading.

ii) The precision ofmeasurement should be no greater than 5% of themaximumdisplacementforthetest.

Recordingofdeformationisatthediscretionoftheengineerrequestingthetestandwill generally depend on the type of test (proof or ultimate). The three typicaldeformationmeasurementprofilesadoptedduringsitetestingareasfollows:

i) None:measurement of deformation is typically not warranted for proof testswhereverylittle(ifany)visibledeformationoccurs.Afastenerexhibitingvisiblemovementuptotheproofloadwilloftenbedeemedafailure.Forapplicationswhere serviceability function is critical for the fastener, displacementmeasurementsshouldbetaken.

ii) Firstvisual:ifvisibledeformationisobserved,asuitablemethodofmeasurementsuch as a dial gauge should be adopted to quantify the relative deformationbetweenthefastenerheadandthesurfaceofthesubstrate.

iii) Detailed: where the intent of the site test is to reproduce the load-deflectioncharacteristics of the fastener’s performance, it is recommended thatdisplacementmeasurements occur at load intervals equal to one-tenth of theultimateloadexpectedoratshorterintervals.

Careshouldbetakenwhenmeasuringdeformation,particularlyregardingthechosenreferencepoint.Deformationmeasurementsontestapparatusaretypicallyglobalinnatureandincludestretchingordeformationofvariouscomponentsofthetestrigthataredifficulttocompensatefor.Consequently,itisstronglyrecommendedthatthepointofreferenceisbeyondthezonewhereaconcreteconemayformandthatisindependenttoanypartofthetestdevice.Further,measurementshouldnotbemadefromanypointonthetestrigsincethiswillexperiencedeformationduringtesting.

Where‘firstmovement’requiresdetection,asimplevisualassessmentmaybemadeof a gap opening in the fixture. If the serviceability limit is to be assessed at themanufacturer’srecommendedload,feelergaugesmaybeusedtoassessthegapinthe fixture, taking care to ensure the gapmeasured is representative of fastenerdisplacement.Forsafety-criticalapplications,ineitherProoforUltimateLoadTests,movementshouldbemonitoredtoensurethataserviceabilitylimitisnotexceededbeforetheDesignLoadisreached.

Intheeventthatdetailedrecordingsarerequiredadialgaugeoramoresophisticatedelectronicdataacquisitionsystemshouldbeadopted.Whendetailedrecordingsandapullingplateassemblyarerequired,directmeasurementsoftheheadofthefastenermaybemade (refer toFigure6).Directmeasurementprovides themostaccuraterecordingofdisplacement;however, themeasuringequipmentmaybedamagedif

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thefastenerfails.Toavoidthepossibilityofdamagingthemeasuringequipment,aneccentricattachmentmaybeintroducedtofacilitatemeasurementoftheheadofthefastener as illustrated in Figure 6. If an eccentric displacement measurement isperformed(e.g.ononesideoftheplate),errorsarepossiblesincethefastenermayexperiencerotationduringloading,resultinginanapparentincreaseordecreaseinthedisplacementmeasurement.Careshouldbetakenasthiserrormaygounnoticedduringtestingsincethetestermaynotbeabletodetectbendingvisually.

Theapplicationofatorqueduringinstallationofafastenerresultsinapreloadthatwilldelaydisplacementuntilthepreloadhasbeenovercomebytheappliedload.Thepermissibledeformationof the fasteningmaybegovernedby serviceability limitsspecific to the project that will determine when the test should terminate. Theserviceabilitylimitfordeformationshouldnotbereachedbeforeachievingthedesignload.Theexpecteddisplacementwill alsodependon the typeof fastener,withanexample being displacement-controlled expansion fasteners which are likely toexperience relatively less displacement prior to failure compared to torque-controlledexpansionfastenerswhichhaveafollow-upexpansioncapability.

(a)Elevation. (b)Planview.

Figure6:Exampletestrigsetfordetaileddisplacementmeasurement(sectionview).

In the event that detailed deformationmeasurements are required, the followingprocedureshouldbeadoptedfortheapplicationofload:

1. Recordings of displacement are made at predetermined intervals, such as1/10th ultimate load or proof load, depending on the type of test beingconducted.Sufficientresolutionshouldbeavailable intheresultsto identifytheload-displacementcurveofthefastener.Itisrecommendedthattheloadingregimeincludemeasurementswhenthedisplacementequals0.1mm,aswell

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as when the design load or manufacturer’s recommended applied load isachieved.Ifthefastenerisnottightenedduringinstallation,theloadreadingat0.1mmdisplacementmaynotberelevant.

2. Itisrecommendedthataverysmall‘bedding-in’load(<100Nornogreaterthan5%oftheestimatedstrengthofthefastening)beappliedatthebeginningofthetesttohelpcorrectforanyoffsetpresentinthedisplacementmeasuringequipmentandarecordingmadeoftheloadanddisplacement.

3. Upon reaching the endof a load interval, record the load anddisplacementreadings.

4. Resumeloadinguntiltheproofloadorultimateloadisachieved.5. Recordthemaximumloadachieved,failuremodeobservedandanydamagesustainedbythestructure.

6. Deduct the displacement recorded from the ‘bedding-in’ load from alldisplacement measurements and plot the resultant load-displacementrelationship.

6.3. Summary of test equipment Thetestequipmenttypicallyrequiredwillinclude:

• Loadingframe• Hydrauliccylinder• Loadgauge• Displacementtransducerwithsuitablemount(ifrequired)• Couplerorsuitableconnectiontofastener• Pullingrod• Sphericalwasher(optional)

7. Test regime

7.1. Application of load Inall cases the loadshouldbeappliedprogressively,withoutabruptchangesorasharp stepped behaviour if the application of load is via a hand operated pump.Suddenchangesinloadmayleadtoerroneousresultsandprematurefailureduetoasuddenspikeinload.

Thenatureofloadingwillbeinfluencedbythechosendisplacementmeasurementprofile.Loadrelaxationmayoccurduetomanyfactorssuchaspressurereleaseintestequipment,slipbetweenfastenercomponents,slipbetweenthefastenerandwallofthehole,formationofmicro-crackswithinthesubstrate,elasticdeformationwithin

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thefastenersystem,aswellasotherfactors.Consequently,correspondingloadanddisplacement measurements should be recorded as close together as possible toavoidtheeffectsofloadrelaxationontheresults.

The increase in loadshouldoccurataratesuchthat thepeak load isexperiencedbetweenonetothreeminutesfromthecommencementofthetest.

It ishighly recommended that the testbewitnessedbya representative from theclientorengineerrequestingthetests.

Note:Testingfastenersmaybedangerous,particularlywhentestingtoultimateloadorfailure.Whenpullingrodsintensionnopersonshouldstandinlinewiththerod.Beforecommencing the tests, all necessary precautions such as the wearing of personalprotective equipment should be taken to mitigate the risk of injury to the tester,witnessesandanybystanderspresentduringtesting.

The number of required tests should be assessed on a case-by-case basis by theengineerrequestingthetests.TheminimumnumberoftestsisrecommendedintherespectiveVolumes2to4ofthisseries.

8. Additional requirements for tests

8.1. General Ifthefastenermanufacturerdoesnotapprovetheiruseinthegeneralcategoryofthesubstrate,sitetestingshouldnotbeconsideredasuitablemethodofdemonstratingsatisfactoryperformance.Some fastenersarenotcompatiblewithcertain typesofsubstrate (e.g. expansion fasteners in hollowmasonry). Manufacturer’s literatureshouldalwaysbeconsultedtodeterminesuitabilityofaproduct.

Wherethepropertiesofthesubstrateareknownormaybereadilyidentified,designdata is available for the substrate properties, and installation is performed by acompetent individual under appropriate supervision, site testing is generally notrequired.

Theremaybecertainspecialapplicationswhereby industry-specific requirementsmay be published forwhich the fastenermanufacturer should be able to provideguidance.

9. Report of results AlistoftheinformationtobeincludedinthetestreportisprovidedinAppendixA.

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10. Summary ThisTechnicalNoteprovidesgeneralrecommendationsforthesitetestingofsafety-criticalfastenersforthepurposeofprooftestingandtoevaluateultimatestrength.Recommendations have been provided for proper test setup, including test rigpositioning,connectiontothefastener,displacementmeasurementandapplicationof load. Provided the substrate properties are known, the fastener has a suitableprequalificationsuchasanETAforthesubstrate,andthefastenerisinstalledaspermanufacturer’sinstallationinstructionsbyasuitablyqualifiedinstaller,sitetestingisgenerallynotrequired.However,theresponsibleengineermayelecttospecifysitetestingforaddedconfidenceintheinstallation.Whileprooftestsareperformedtoverify correct installation, the purpose of ultimate tests is to determine ultimatestrengthofthefastening.AppendixBprovidesasummaryoftestregimes.

The advice provided is not exhaustive and should be used together with adviceprovidedintheothervolumesofthisseriesasappropriatetothetypeoftestingbeingconducted.

11. References [1] British Standard 8539, “Code of practice for the selection and installation of

post-installedanchorsinconcreteandmasonry”,BSIStandardsLimited2012

[2] Construction Fixings Association, “Procedure for Site Testing ConstructionFixings”,GuidanceNote,www.fixingscfa.co.uk

[3] AEFACTechnicalNote07,“AEFACFastenerDictionary”,www.aefac.org.au

[4] EAD330232,“Mechanicalfastenersforuseinconcrete”,EOTA,2016

[5] AS 5216:2018, “Design of post-installed and cast-in fastenings in concrete”,StandardsAustralia

[6] EOTATR053“Recommendationsforjob-sitetestsofmetalinjectionanchorsforuseinmasonry”,www.eota.eu,2016

[7] Construction FixingsAssociation, “How to test anchors on site in accordancewithBS8539:2012”,GuidanceNote,www.fixingscfa.co.uk

[8] AEFAC Technical Note 01, “Design Concepts for Post-Installed and Cast-InFasteners”,www.aefac.org.au

[9] AEFAC Technical Note 02, “Prequalification of Post-Installed and Cast-InFasteners”,www.aefac.org.au

[10] EAD330499,“Bondedfastenersforuseinconcrete”,EOTA,2017

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APPENDIX A TEST REPORT

Thefollowingprovidesalistofminimuminformationthatshouldberecordedandreportedtothedesignengineer/specifier.Additionalinformationmaybewarrantedsubjecttosite-specificconsiderations.

Thepurposeofthetestreportistoidentifyifallobjectivesofthetest(s)havebeenmet,aswellasanydeviations.

A.1 Administration details • Dateoftest• Reasonfortest• Nameofpersonrequestingtest• Reportreferencenumber• Client’scompanyname,address,contactnameandposition• Sitelocation,contactnameandposition• Nameandcompanyoftesterwithjobtitleand/orappropriatequalifications• Nameandcompaniesofwitnesses• Nameandcompanyofinstalleroffasteners

A.2 Anchor/application details • Nameofmanufacturer• Anchortype,sizeandfinish• Proposedapplicationoffastener• Design resistance and manufacturer’s recommended resistance in the basematerialconcerned(forprooftests)

A.3 Test objectives • Prooftestsorultimatetests• Requiredloadforprooftests(ifapplicable)

A.4 Test location • Detail of the location of each test within the structure with sketch whereappropriate

• Edgedistance,centrespacingandstructuralthickness,ifappropriate

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A.5 Base material • Typeandstrengthattimeoftest,ifknown• Whethersolid,holloworperforatedunits(masonry)

A.6 Installation details If the installation is carriedoutby the tester, the following information shouldbereported:

• Nominalholediameter• Drillbitcuttingdiameter,recordedto0.1mm• Drillingmethod/tools• Holedepth• Effectiveembedmentdepth• Holecleaningmethodindetail• Prescribedinstallationtorqueandtighteningtorqueapplied• Forbondedfasteners(ifapplicable):o Ambienttemperaturewheninstalledo Manufacturer’srecommendedcuringtimeo Actualcuringtimeallowed

A.7 Test equipment details • Make,typeandloadcapacityofhydraulicram/gaugeortester• Dateoflastcalibration,calibratingauthority• Makeandtypeofmovementrecorder,dialgauge,etc.• Loadingframe:distancebetweenfastenerandclosestsupport• Makeandrangeoftorquewrench

A.8 Test results Theinformationreportedisdependentonthenatureofthetestundertaken.

A.8.1 Load

• Maximumload• Conditionoffastenerandsurroundingbasematerialbeforeandaftertest• Loadatfirstvisiblemovement

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A.8.2 Movement

Ifrequired,theloadshouldbereportedatdifferentloadincrementsspecifiedbytheengineerrequestingthetests,aswellasthemaximumload.

A.8.3 Mode of failure

Singleormultiplemodesoffailureobservedincludingthefollowingpossiblemodes:

• Base material: cone failure, spalling, splitting, cracking, blow-out failure, bondfailure(chemicalfasteners),combinedcone-bondfailure(chemicalfasteners)

• Steelfailure:fracture• Pull-out/excessivemovement

A.8.4 Method statement A.8.5 Gauge calibration certificate A.8.6 Test summary

• Statementofwhetherthetestprocedurewasfollowedincludingasummaryofanydeviations

• Statementregardingwhetherornotthetestobjectiveswheremet

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APPENDIX B:

SUMMARY OF TEST REGIMES

FigureB1:Flowchartoftestregimes

Disclaimer: The information provided in this Technical Note is intended forgeneralguidanceonly,andinnowayreplacestheservicesofdesignengineersonparticular projects or subjects. AEFAC and its board, constituent members,representativesoragentswillnotbeliableforanyclaimsordamageswhatsoeverresultingfromuseorrelianceoninformationinthisTechnicalNote.

www.aefac.org.au

site testing - vol1 - revised - aefac · 2020. 4. 15. · these guidelines have been based on...

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