Designation:D4694−09(Reapproved2015)StandardTestMethodforDeflectionswithaFalling-Weight-TypeImpulseLoadDevice1ThisstandardisissuedunderthefixeddesignationD4694;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthemeasurementofdeflectionsofpavedandunpavedsurfaceswithafalling-weight-typeimpulseloaddevice.ThesedevicesarecommonlyreferredtoasfallingweightdeflectometersorFWDs.1.2Thistestmethoddescribesthemeasurementofverticaldeflectionresponseofthesurfacetoanimpulseloadappliedtothepavementsurface.Verticaldeflectionsaremeasuredontheloadaxisandatpointsspacedradiallyoutwardfromtheloadaxis.1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.AspecifichazardstatementisgiveninSection6.2.ReferencedDocuments2.1ASTMStandards:2D4695GuideforGeneralPavementDeflectionMeasure-ments2.2StrategicHighwayResearchProgram:LongTermPavementPerformanceProgramManualforFallingWeightDeflectometerMeasurements,Version4.1,December20063.SummaryofTestMethod3.1Thistestmethodisatypeofplate-bearingtest.Theloadisaforcepulsegeneratedbyaweightdroppedonabuffersystemandistransmittedthroughaplaterestingonthepavementsurface.Thetestapparatusmaybemountedinavehicleoronasuitabletrailertowedbyavehicle.3.2Thevehicleisbroughttoastopwiththeloadingplatepositionedoverthedesiredtestlocation.Theplateanddeflec-tionsensorsareloweredtothepavementsurface.Theweightisraisedtotheheightthat,whendropped,willimpartthedesiredforcetothepavement.Theweightisdroppedandtheresultingverticalmovementordeflectionofthepavementsurfaceismeasuredusingsuitableinstrumentati...
