ASTM_D_7538_-_09_2013.pdf

Designation:D753809(Reapproved 2013)Standard Practice forEvaluating the Water Wash-Off Resistance of Traffic PaintsUsing an Atomizing Spray Device1This standard is issued under the fixed designation D7538;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 Anewly applied traffic paint film may be exposed to rainof varying intensities shortly after application.Practice D7377describes a practice for evaluating the water wash-off resis-tance of traffic paints to a hard rain using a steady stream ofwater from a faucet at a rate of approximately 5.7 L per min.Practice D7538 is a similar practice that describes the use of anadjustable nozzle atomizing spray device to deliver a spray ofwater that simulates rain rates from approximately 0.05 to 0.5L per min.This test can be used to compare conventional andfast-dry traffic paints for their relative ability to withstand rainsoon after application on roadway surfaces.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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:2D562 Test Method for Consistency of Paints MeasuringKrebs Unit(KU)Viscosity Using a Stormer-Type Viscom-eterD711 Test Method for No-Pick-Up Time of Traffic PaintD823 Practices for Producing Films of Uniform Thicknessof Paint,Varnish,and Related Products on Test PanelsD1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD1212 Test Methods for Measurement of Wet Film Thick-ness of Organic CoatingsD3924 Specification for Environment for Conditioning andTesting Paint,Varnish,Lacquer,and Related MaterialsD4414 Practice for Measurement of Wet Film Thickness byNotch GagesD7377 Practice for Evaluating the Water Wash-Off Resis-tance of Traffic Paints using a Water Faucet3.Terminology3.1 Definitions:3.1.1 conventional waterborne traffc paint,nan aqueoustraffic paint that uses a conventional-dry latex binder.3.1.1.1 DiscussionTypical no-pick-up dry times,as pre-scribed in Test Method D711,for conventional traffic paints are20 to 45 min.3.1.2 durable fast-dry waterborne traffc paint,nan aque-ous traffic paint that uses a third generation durable fast-drylatex binder.3.1.2.1 DiscussionAir or airless spray application onroadways is typically 0.64 mm wet or about 0.39 mm dry.Therange of application for durable waterborne paints is 0.56 to0.89 mm wet,but sometimes the durable paints are also stripedat standard line thickness.3.1.3 fast-dry waterborne traffc paint,nan aqueous trafficpaint that uses a fast-dry traffic latex binder.3.1.3.1 DiscussionTypical no-pick-up dry times,as pre-scribed in Test Method D711,for fast-dry traffic paints are 10min.3.1.4 standard line fast-dry waterborne traffc paint,nanaqueous traffic paint that uses a first or second generationfast-dry latex binder.3.1.4.1 DiscussionAir or airless spray application onroadways is typically 0.38 mm wet or about 0.23 mm dry.3.1.5 waterborne traffc paint,nan aqueous traffic paint(usually white or yellow)containing either a conventional orfast-dry latex binder.3.1.6water wash-off,nthe erosion or removal of freshlyapplied traffic paint in the field by rain or in the laboratoryusing simulated rain.3.1.6.1 DiscussionSometimes referred to as water wash-out.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.44 on Traffic Coatings.Current edition approved Nov.1,2013.Published November 2013.Originallyapproved in 2009.Last previous edition approved in 2009 as D7538 09.DOI:10.1520/D7538-09R13.2For 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.Summary of Practice4.1 This practice involves preparing a series of uniformthickness films of traffic paint on standard substrates.The filmsare allowed to dry over different time periods in a conditionedenvironment,and then each paint film is subsequently sub-jected to a water spray.Films are wash-off resistant when nopaint is removed by the water spray.5.Significance and Use5.1After waterborne traffic paints are applied to a roadpavement,it is important that they be sufficiently coalesced orcured