1、Designation:C124617Standard Test Method forEffects of Heat Aging on Weight Loss,Cracking,andChalking of Elastomeric Sealants After Cure1This standard is issued under the fixed designation C1246;the number immediately following the designation indicates the year oforiginal adoption or,in the case of
2、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 a laboratory procedure fordetermining the effects of heat aging on weight loss
3、,crackingand chalking of elastomeric joint sealants(single and multi-component)for use in building construction.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 The committee having jurisdiction for this specificationis n
4、ot aware of any similar ISO standard.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 and health practices and determine the applica-bility of regulatory limita
5、tions 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 Te
6、chnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2C717 Terminology of Building Seals and SealantsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsDefinitions of the following terms arefound in T
7、erminology C717:cure,elastomeric,joint,sealant,self-leveling sealant,standard conditions.4.Summary of Test Method4.1 Sealant is spread on three aluminum panels and the netweight of sealant on each panel is determined.After the threesealant specimens are allowed to cure for 28 days at standardconditi
8、ons,two specimens are then heat-aged for 21 days in aforced-draft oven maintained at 706 2C(158 6 3.6F).Thepercentage weight lost during the heat aging period is thendetermined and examination is made for presence of cracks andchalking.5.Significance and Use5.1 Weight loss from a sealant after appli
9、cation in a buildingjoint can be detrimental to long term sealant durability.Asealants service life will be shortened if it containscomponents,critical to its durability,that are volatilized byhigh environmental temperatures.Also,development of cracksand chalking lessens a sealants service life.5.2
10、The test described herein measures weight loss,cracking,and chalking.The amount of weight lost during theheat aging period and any cracking or chalking helps predictpremature sealant failure.However,a sealant developing nocracks or chalking,or low weight loss in this test,does notnecessarily ensure
11、good durability.6.Apparatus6.1 Forced-Draft Oven,controlled at 70 6 2C(158 63.6F).6.2 Balance,sensitive to 0.01 g.6.3 Rectangular Brass or TFE-Fluorocarbon Frame,withinside dimensions 130 by 40 by 3.2 mm(5 by 112by18in.).6.4 Aluminum Panels,three,each 152 by 80 by 0.6 to 1.6mm(24 to 16 gage)(6 by 3
12、by 0.024 to 0.0625 in.).6.5 Straight Edge,metal or plastic,about 152 mm(6 in.)long.6.6 Thin Knife Blade.6.7 Spatula,steel,about 152 mm(6 in.)long.7.Procedure7.1 Unless otherwise specified by those authorizing the test,standard conditions shall be used.1This test method is under the jurisdiction ofAS
13、TM Committee C24 on BuildingSeals and Sealants and is the direct responsibility of C24.20 on General TestMethods.Current edition approved June 1,2017.Published June 2017.Originallyapproved in 1993.Last previous edition approved in 2012 as C1246 00(2012).DOI:10.1520/C1246-17.2For referenced ASTM stan
14、dards,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 19428-2
15、959.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 B
16、arriers to Trade(TBT)Committee.1 7.2 Test of Multicomponent Sealants:7.2.1 Condition at least 400 g of base compound andappropriate amount of curing agent in closed containers for atleast 24 h at standard conditions;then mix thoroughly togetherfor five min.7.2.2 Weigh each of the three aluminum panels to thenearest 0.01 g.7.2.3 Center the brass frame on an aluminum panel.Fill theframe with the mixed compound and strike it off flat with thestraightedge.Run a thin-bladed knife along the inside of
