2019/12/18

ZC3-A Concrete Rebound Tester


productdescription:ThisinstrumentisaconcretereboundmeterthatfullycomplieswiththeindustrystandardJGJ/T23-2011"TechnicalRegulationsforTestingtheCompressiveStrengthofConcretebyReboundMethod".Itisusedtodetectthecompressivestrengthofradonintherangeof10-60Mpa.ThenominalenergyofthereboundmeterItis2.207J,andtheindicationsystemisapointerdirect-readingmediumreboundtester.ThetechnicalparametersoftheinstrumentareinaccordancewiththevarioustechnicalspecificationsoftheNationalMetrologicalVerificationRegulationofthePeople'sRepublicofChina"ConcreteReboundTester"(JJG817-2011).TechnicalParameters:●Handlength:20.0±0.2(mm)●Handfriction:0.65±0.15(N)●Sphericalradiusoftheendofthebouncerod:25±1.0(mm)●Rigidityofbouncetensionspring:785.0±30.0(N/m)●Unhookpositionofthebouncehammer:atthescaleline"100"●Workinglengthofbouncetensionspring:61.5.0±0.3(mm)●Theimpactlengthofthehammer:75±0.3●Bouncingpositionofbouncehammer:"0"onthescale●Fixedvalueofsteelanvil:80±2       Performancecharacteristics:Theconcretereboundtesterusesaspringtodrivethehammerandtherestorationforceoftheinstantaneouselasticdeformationgeneratedbyhittingtheconcretesurfacebythehammer,sothatthehammerwilldrivethepointertoreboundandindicatetherebounddistance.Thereboundvalue(theratiooftherebounddistancetothedistancefromthehammertothehammerbeforeimpact,calculatedasapercentage)isusedasoneoftheindicatorsrelatedtothecompressivestrengthofconcretetoestimatethecompressivestrengthofconcrete.Itisaninstrumentfornon-destructivetestingofthecompressivestrengthofconcreteinstructuresorcomponents.Thisinstrumentislight,flexible,inexpensive,doesnotrequirepower,thebuttonisnoteasytofallusingthestretchingprocess,thepointeriseasytoadjustthefriction,anditiseasytograsp.Itisverysuitableforon-siteconstructionsites,plusthecorrespondingreboundgaugeverificationproceduresandreboundmethod.Theformulationandimplementationoftechnicalregulationsfortestingthecompressivestrengthofconcretehaveensureditsdetectionaccuracy,andhavebeenwidelyusedinChina'sconstructionindustry.

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2019/12/18

Use of rebound tester


1.Holdtheimpactrodagainsttheconcretesurface,andpresstheinstrumentlightlytoreleasethebutton.Whenthepressureisrelaxed,theimpactrodextends,andthehookishungwiththeimpacthammer.2.Maketheinstrumentaxisalwaysperpendiculartotheconcretesurfaceandapplypressureslowlyandevenly.Afterthehammerhitstheimpactbar,thereboundofthehammerwillmovethepointerbacktoacertainposition.Thescoreshowsacertainvalueonthescaleasthereboundvalue. 3.Keeptheinstrumentmovementagainsttheconcretesurfacereadingandrecordthereboundvalue.Iftheconditionsarenotconducivetoreading,pressthebuttontolockthemovementandmovetheinstrumenttotakethereading. 4.Graduallydepressurizetheinstrumentsothattheejectionrodprotrudesfromtheinstrumentuntilthenextuse. MaintenanceofthereboundtesterRoutinemaintenanceshouldbeperformedwhenthereboundtesterhasoneofthefollowingconditions:1.Bouncingmorethan2,000times;2.Whenindoubtaboutthetestvalue;3.Thesteelanvilrateisnotqualified; Routinemaintenancemethodsshouldmeetthefollowingrequirements:1.Unhookthehammer,thenremovethemovement,thenremovethehammer(removethebufferpressurespringinside)andthethreepieces(thehammer,thespringtensionspringandthespringspringseat); 2.Usegasolinetocleanallpartsofthemovement,especiallytheinnerguideandimpactsurfaceofthecenterguiderod,hammerandhammer.Aftercleaning,applyathinlayerofwatchoilorsewingmachineoiltothecenterguidebar,andotherpartsmustnotbeoiled;3.Washtheinnerwallofthecabinet,removethescale,andcheckthatthefrictionofthepointershouldbebetween0.5-0.8N; 4.Donotrotatethezeroingscrewthatispositionedandfastenedonthetailcover;5.Don'tmakeorreplacepartsbyyourself;6.Aftermaintenance,thecalibrationtestshouldbeperformedaccordingtorequirements,andthecalibrationvalueshouldbe80±2.VerificationofthereboundtesterThereboundtestershallbesenttothelegaldepartmentforverificationwhenoneofthefollowingconditionsexists.Aqualifiedreboundtestershallhaveaverificationcertificate:1.Beforethenewreboundtesterisactivated;2.Exceedthevalidityperiodoftheverification(validityperiodishalfayear); 3.Cumulativenumberofbouncesexceeds6,000; 4.Thesteelanvilrateisnotqualifiedafterroutinemaintenance; 5.Sufferingfromsevereimpactorotherdamage.

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2019/12/18

Rebound method for testing concrete strength


Theinstrument,principleandmethodofreboundconcretefortestingconcretestrength,aswellasthefactorsaffectingthestrengthoftesting,areintroduced,andthemostextensive,simple,andaccuratemethodfordeterminingconcretestrengthisprovidedfornondestructivetesting.Keywords:carbonizationdepth;reboundvalue;compressivestrength;concrete  Therearemanydetectionmethodsforon-sitetestingofconcretestrength,suchascoredrillingmethod,pull-outmethod,indentationmethod,shootingmethod,reboundmethod,ultrasonicmethod,reboundultrasoniccomprehensivemethod,ultrasonicattenuationcomprehensivemethod,raymethodfallingballmethod,etc.Thereboundmethodandultrasonicreboundmethodarethemostwidelyusednon-destructivetestingmethods.Therelationshipcurveestablishedbetweenthecompressivestrengthofconcretetestblocksandtheparametersofnondestructivetesting(ultrasonicsoundvelocityvalue,reboundvalue,pull-outforce,etc.)iscalledthestrengthcurve,whichisthebasisforestimatingtheconcretestrengthofnondestructivetesting.Thestrengthcurveisdividedintothreetypes:unifiedstrengthcurve,regionalstrengthcurveandspecial(calibrated)strengthcurveaccordingtothesourceofthematerial.Themethodofdetectingthecompressivestrengthofordinaryconcretestructuralmembersbyusingareboundinstrument(adirect-actinghammertypeinstrument)isreferredtoasthereboundmethod.Thefollowingfocusesonthereboundmethodfortestingconcretestrength.1Detectionprincipleandcharacteristics1.1Principle  Becausethereisacorrelationbetweenthecompressivestrengthofconcreteanditssurfacehardness,thereboundhammerofthereboundmeterishitbyacertainelasticforceontheconcretesurface,anditsreboundheight(reboundvaluereadbythereboundmeter)Itisproportionaltothehardnessoftheconcretesurface.Therefore,thereboundvalueAccordingtothesurfacehardnessofconcrete,thecompressivestrengthofconcretecanbeestimatedbasedonthesurfacehardness.1.2Features  Thereboundmethodisusedtotestthecompressivestrengthofconcrete.Althoughthedetectionaccuracyisnothigh,theequipmentissimple,easytooperate,quicktotest,andlowintestingcost,anddoesnotdamagethenormaluseofconcrete.Therearemanyfactorsthataffecttheaccuracyofthereboundmethod,suchasoperatingmethods,instrumentperformance,andclimaticconditions.Forthisreason,youmustmasterthecorrectoperationmethod,payattentiontothemaintenanceandcalibrationofthereboundmeter.  "TechnicalSpecificationsforTestingtheCompressiveStrengthofConcretebytheReboundMethod"(JGJ/T23-2001)stipulatesthattheageoftheconcretemeasuredbythereboundmethodis7dto1000d,whichisnotapplicabletothesurfaceandinternalqualitywithobviousdifferencesorinternalexistenceThedetectionofdefectiveconcretecomponentsandconcretemadebyspecialmoldingprocessesgreatlylimitsthedetectionrangeofthereboundmethod.Inaddition,duetothelargestrengthbaseofhigh-strengthconcrete,eveniftherelativeerrorisonly15%,Itsabsoluteerrorwillalsobeverylargeandmakethetestresultmeaningless.

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2019/12/18

Correct operation of rebound meter


Correctoperationofreboundmeter1.Holdtheimpactrodagainsttheconcretesurface,andpresstheinstrumentlightlytoreleasethebutton.Whenthepressureisrelaxed,theimpactrodextends,andthehookishungwiththeimpacthammer.2.Maketheaxisoftheinstrumentalwaysperpendiculartotheconcretesurfaceandapplypressureslowlyandevenly.Afterthehammerisunhookedandimpactsthehammer,thehammerwillreboundtodrivethepointer.Whenmovingbackwardtoacertainposition,theindicatedvalueonthepointerblockshowsacertainvalueonthescaleasthereboundvalue.3.Keeptheinstrumentmovementagainsttheconcretesurfacereadingandrecordthereboundvalue.Iftheconditionsarenotconducivetoreading,pressthebuttontolockthemovementandlocktheinstrument.Moveelsewheretoread.4.Graduallydepressurizetheinstrumentsothattheejectionrodprotrudesfromtheinstrumentuntilthenextuse. Routinemaintenanceshouldbeperformedunderoneofthefollowingconditions:1.Bouncingmorethan2,000times;2.Whenindoubtaboutthetestvalue;3.Thesteelanvilrateisnotqualified;Routinemaintenancemethodsshouldmeetthefollowingrequirements:1.Unhookthehammer,thenremovethemovement,thenremovethehammer(removethebufferpressurespringinside)andthethreepieces(thehammer,thespringtensionspringandthespringspringseat);2.Usegasolinetocleanallpartsofthemovement,especiallytheinnerguideandimpactsurfaceofthecenterguiderod,hammerandhammer.ThinlyonthecenterguideaftercleaningApplyalayerofwatchoilorsewingmachineoil,andotherpartsmustnotbeoiled;3.Washtheinnerwallofthecabinet,removethescale,andcheckthatthefrictionofthepointershouldbebetween0.5-0.8N;4.Donotrotatethezeroingscrewthatispositionedandfastenedonthetailcover;5.Don'tmakeorreplacepartsbyyourself;6.Aftermaintenance,thecalibrationtestshouldbeperformedaccordingtorequirements,andthecalibrationvalueshouldbe80±2. VerificationofreboundtesterThereboundmetershouldbesenttothelegaldepartmentforverificationifoneofthefollowingconditionsexists,andthequalifiedreboundmetershouldhaveaverificationcertificate:1.Beforethenewreboundtesterisactivated;2.Exceedthevalidityperiodoftheverification(validityperiodishalfayear);3.Cumulativenumberofbouncesexceeds6,000;4.Thesteelanvilrateisnotqualifiedafterroutinemaintenance;5.Sufferingfromsevereimpactorotherdamage.

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2019/12/18

Several methods of nondestructive testing


SeveralmethodsofnondestructivetestingManynon-destructivetestingmethodsAccordingtoNASAresearchandanalysis,itisbelievedthattheycanbedividedintomorethan70categoriesinsixcategories.However,thefollowingaremorecommoninpracticalapplications:Theconventionalnon-destructivetestingmethodsare:UltrasonicTesting(abbreviationUT);RadiographicTesting(RT)Magneticparticletesting(abbreviationMT);PenetrantTesting(abbreviationPT);EddycurrentTesting(abbreviationET);Non-conventionalnon-destructivetestingtechnologiesare:AcousticEmission(AE)LeakTesting(abbreviationUT);OpticalHolographyInfraredThermography;MicrowaveTesting1.Whatisradiographicinspection?Thetechniqueofdetectingthediscontinuityoftheinternalstructurebyusingtheattenuationoftherays(X-rays,γ-rays,neutronrays)astheypassthroughamaterialorworkpieceiscalledraydetection.TherayspassingthroughthematerialorworkpiecehavedifferentsensitivitylevelsontheX-rayfilmduetodifferentintensities,therebygeneratinginternaldiscontinuousimages.2.Whatisultrasonictesting?Whenultrasonicwavespropagatethroughthetestedmaterials,theacousticcharacteristicsofthematerialsandchangesintheinternaltissueshaveacertaineffectonthepropagationofultrasonicwaves.Thetechniqueofunderstandingthepropertiesandstructuralchangesofmaterialsthroughthedetectionofthedegreeandconditionofultrasonicwavesiscalledultrasonictesting.3.Whatismagneticparticledetection?Non-destructivetestingmethodfordiscontinuitiesonthesurfaceandnearsurfaceoftestspecimensusingmagneticfluxleakageandsuitableinspectionmedia.4.Whatispenetrationtesting?Thecapillaryactionoftheliquidisusedtoinfiltratethepenetrantintotheopendefectsonthesurfaceofthesolidmaterial.Then,theinfiltratingpermeateissuckedouttothesurfacebythedevelopertoshowtheexistenceofdefects.Thisnon-destructivetestingmethodiscalledpenetrationtesting.5.Whatiseddycurrentdetection?Thenon-destructivetestingmethodthatusestheeddycurrentinducedintheworkpiecebytheferromagneticcoiltoanalyzetheinternalqualityoftheworkpieceiscallededdycurrenttesting.

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