ASTM_D_7735_-_11e1.pdf

Designation:D7735111Standard Test Method forType A Durometer Hardness Testing of Road MarkingThermoplastic at Elevated Temperatures1This standard is issued under the fixed designation D7735;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.1NOTESection 6.4 was corrected editorially in January 2014.1.Scope1.1 This test method covers Type A Durometer hardness ofroad marking thermoplastic material at elevated temperatures.1.2 This test method is similar to Test Method D2240 forhardness with special attention given to keeping the tempera-ture of the test sample and instrument constant.Within thehighway materials community,it is sometimes known as“indentation resistance.”1.3 All materials,instruments or equipment used for thedetermination of temperature,hardness and time shall betraceable to National Institute of Standards and Technology orother internationally recognized organizations parallel in na-ture.1.4 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.5 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:2D16 Terminology for Paint,Related Coatings,Materials,andApplicationsD2240 Test Method for Rubber PropertyDurometer Hard-nessD7307 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 Definitions:3.1.1 The terms and definitions in Terminology D16 applyto this method.3.1.2 hardness,advthe value of resistance of a smallpenetrating device.In the case of the Type A Durometer inaccordance with Test Method D2240,the presser foot/indentor(spherical to 0.79 6 0.03 mm or 0.03 6 0.001 in.)is connectedto a spring loaded to a total of 0.075 N/Durometer units at fulldeflection.For reading of Type A hardness the instrumentsscale reads from 0 to 100.Minimal deflection is 0(softest)andmaximum is 100(hardest).3.1.3 thermoplastic,ntraffic marking(same as 3.1.4).3.1.4 thermoplastic traffc markinga highly filled 100%total solids highway marking system that when heated to amolten state can be extruded or sprayed onto a road surface andwhen cooled forms a solid durable delineator or road markingthermoplastic usually melted to 220C(425F).4.Summary of Test Method4.1 This method was developed to enable the testing ofhardness or indentation resistance of road marking thermoplas-tic material at ambient roadway/highway temperatures.Due tothe speed at which basic road marking thermoplastic cools,testing its hardness at elevated temperatures is difficult,even ata relatively low 46C(115F).Existing non-standard methodsare not consistent because they allow the samples to changetemperature during testing.By keeping both the test samplesand the hardness tester in a regulated environment before andduring testing,the results are much more repeatable within alaboratory.The goal for this method is to allow results fromthis test to be more reproducible from laboratory to laboratory.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 Nov.1,2011.Published December 2011.DOI:10.1520/7735-11E01.2For 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 4.2 The methodology involves measuring the hardness ofroadmarking thermoplastic by keeping the test sample in theelevated temperature environment(a water bath)during thetesting process and using a Durometer that can be placed in thewater bath and function.This method could be performed in aglove box/oven if the door was not opened before or during thetesting.5.Significance and Use5.1 This method is based on the penetration of a specifictype of indentor when forced into the material under specifiedconditions.The indentation hardness is inversely related to thepenetration and is dependent on the elastic modulus,viscoelas-tic behavior of the material,geometry of the indentor,theapplied force and temperature at test.This