ASTM_D_6490_-_99_2022.pdf

Designation:D649099(Reapproved 2022)Standard Test Method forWater Vapor Transmission of NonFilm Forming TreatmentsUsed on Cementitious Panels1This standard is issued under the fixed designation D6490;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 covers the determination of the rate atwhich water vapor passes through non film forming treatments,such as silanes,siloxanes and blends of silanes/siloxanesapplied to cementitious substrates.1.2 This test method covers the use of the wet cuptechnique,which most closely approaches the exterior condi-tions for use for these materials.Other conditions can be usedif agreed upon between purchaser and supplier.Agreementshould not be expected between results obtained by differentmethods or test conditions.1.3 The values stated in SI units of measurement aredesignated as the standard.Factors for conversion to inch-pound units are given in 9.2.1.1 and 9.2.2.1.1.4 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D823 Practices for Producing Films of Uniform Thicknessof Paint,Coatings and Related Products on Test PanelsD1193 Specification for Reagent WaterD1734 Practice for Making Cementitious Panels for TestingCoatingsD3924 Specification for Standard Environment for Condi-tioning and Testing Paint,Varnish,Lacquer,and RelatedMaterialsE104 Practice for Maintaining Constant Relative Humidityby Means of Aqueous Solutions3.Summary of Test Method3.1 The treated cementitious substrate is sealed to the openmouth of an assembly containing water with the treated sidefacing the water,and the assembly placed in a test chamberwith a controlled atmosphere maintained at 50 6 5%relativehumidity at 23 6 2 C(73.5 6 3.5 F).Periodic weighings ofthe assembly are made to determine the rate of water vapormovement through the specimen.4.Significance and Use4.1 One of the factors affecting the performance providedby a cementitious treatment is how readily water vapor passesthrough it.Hence,the water vapor transmission characteristicsof treatments are important in assessing their performance inpractical use.4.2 The purpose of this test method is to obtain values ofwater vapor transfer through treatments that range in perme-ability from high to low.These values are for use in design,manufacture,and marketing.4.3 Water vapor transmission is not a linear function of filmthickness,temperature or relative humidity.4.4 Values of water vapor transmission rate(WVT)andwater vapor permeance(WVP)can be used in the relativerating of treatments only if the treatments are tested under thesame closely controlled conditions of temperature and relativehumidity.5.Apparatus5.1 Assembly,consisting of a container,typically with anopening of approximately 75 mm(3 in.)by 150 mm(6 in.).The depth of the dish is such that there is a 20 6 5 mm(0.8 60.2 in.)distance between the water surface and the surface ofthe under surface of the test specimen,with a water depth of at1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.47 on Concrete,Stone and Masonry Treatments.Current edition approved June 1,2022.Published July 2022.Originally approvedin 1999.Last previous edition approved in 2014 as D6490 99(2014).DOI:10.1520/D6490-99R22.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1least 5 mm(0.2 in.).The assembly should be made of anoncorroding material,impermeable to water or water vapor inorder to be found acceptable.The treated cementitious sub-strate