ASTM_D_4796_-_10.pdf

Designation:D479610Standard Test Method forBond Strength of Thermoplastic Traffic Marking Materials1This standard is issued under the fixed designation D4796;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method provides an instrumental means for thedetermination of thermoplastic traffic marking material bondstrengths using cement bricks and loading fixtures.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C109/C109M Test Method for Compressive Strength ofHydraulic Cement Mortars(Using 2-in.or 50-mm CubeSpecimens)D16 Terminology for Paint,Related Coatings,Materials,andApplicationsD4541 Test Method for Pull-Off Strength of Coatings UsingPortable Adhesion TestersD5179 Test Method for Measuring Adhesion of OrganicCoatings to Plastic Substrates by Direct Tensile TestingD7234 Test Method for Pull-Off Adhesion Strength of Coat-ings on Concrete Using Portable Pull-Off Adhesion Tes-tersD7307 Practice for Sampling of Thermoplastic Traffic Mark-ing MaterialsD7308 Practice for Sample Preparation of ThermoplasticTraffic Marking MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 The terms and definitions in Terminology D16 apply tothis method.3.2 Definitions of Terms Specific to This Standard:3.2.1 cement brick,na brick formed by mixing cementand fine sand together and allowing to harden with 210.9 to351.5 kg/cm2(3000 to 5000 psi)compression strength.3.2.2 loading fixture,n(also referred to as dollies,studs,orjigs)metal fixture round and flat on one end for bonding to testsample and shaped on the other end for attaching to tensiletesting device(Fig.1).3.2.3 thermoplastic,ntraffic marking(same as 3.2.4).3.2.4 thermoplastic traffc marking,na highly filled100%total solids highway marking system that when heatedto a molten state can be extruded or sprayed onto a road surfaceand when cooled forms a solid durable delineator or roadmarking thermoplastic usually melted to 218C(425F).4.Summary of Test Method4.1 The thermoplastic specimen is prepared for this test byfirst melting a sample to its application temperature undercontinuous agitation.The specimen is then applied to thespecified cement brick using a hot drawdown bar(Fig.2),heated to 104 6 2C(220 6 5F),at 3.175 mm(125 mils)thickness.While the thermoplastic is still soft,three cuts aremade with a 40.6 mm(1.6 in.)diameter die,heated to 104 62C(220 6 5F),in order to separate the test area from the restof the drawdown.The die may be heated while submerged inglycerin to prevent thermoplastic from sticking to the die.Thetest areas are allowed to cool slightly and then three 40.6 mm(1.6 in.)diameter heated loading fixtures are laid on the testareas.The samples are then allowed to cure overnight beforedetermining the bond strength on a tensile testing device.5.Significance and Use5.1 The function of this test method is to provide numericalinstrumental results indicating the cohesive and/or adhesivebond strength of thermoplastic traffic marking to a specifiedcement brick substrate.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.44 on Traffic Coatings.Current edition approved Dec.1,2010.Published March 2011.Originallyapproved in 1988.Last previous edition approved in 2004 as D4796 88(2004).DOI:10.1520/D4796-10.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2 The use of this test method allows the user and manu-facturer to control the quality of the product and makeinferences about the performance of the thermoplastic trafficmarking product.Results from these tests also provide infor-mation helpful in researching and developing thermoplastictraffic marking materials.5.3 The method has been revised to be more consistent tomethodology in otherASTM bond methods for coatings in TestMethods D4541,D5179,and D7234.5.4 Strict adherence to the procedures outlined is necessaryfor