ASTM_D_1670_-_D_1670M_-_11.pdf

Designation:D1670/D1670M11Standard Test Method forFailure End Point in Accelerated and Outdoor Weathering ofBituminous Materials1This standard is issued under the fixed designation D1670/D1670M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the use of a spark generatingapparatus for determination of failure due to cracking ofbituminous materials undergoing accelerated or outdoor weath-ering on electrically conductive backings.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.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:2D1435 Practice for Outdoor Weathering of PlasticsD1669 Practice for Preparation of Test Panels for Acceler-ated and Outdoor Weathering of Bituminous CoatingsD4798 Practice for Accelerated Weathering Test Conditionsand Procedures for Bituminous Materials(Xenon-ArcMethod)D4799 Practice for Accelerated Weathering Test Conditionsand Procedures for Bituminous Materials(FluorescentUV,Water Spray,and Condensation Method)3.Summary of Test Method3.1 Dry,weathered,bituminous-coated test panels aregrounded and a feeler electrode is passed over the back of alinagraphic or ultra high sensitivity thermal fax paper placed onthe bituminous surface with the emulsion side down.Photo-copies are made of the front side of the paper on which thespots caused by the sparks appear.The photographs arecovered with an acrylic grid and the number of squarescontaining the spark records are counted and reported.Spark-ing in 26 or more grid squares is representative of failure.4.Significance and Use4.1 The extent of cracking or pitting of bituminous films isa measure of the extent of deterioration due to weathering.Failure due to cracking is more accurately determined electri-cally than visually.4.2 Failure determined by this test method will depend notonly on the characteristics of the bituminous material and theextent of weathering,but also on the film thickness,and theamount and type of mineral filler present.4.3 Tests on a similar material of known weathering char-acteristics(a control)exposed at the same time as the testmaterial is strongly recommended as a check on the validity ofthe test results.5.Apparatus5.1 Any Spark-Generating Apparatus3Fig.1 is an ex-ample of an acceptable configuration for the test feeler.Otherconfigurations are not prohibited,subject to the followingconditions:5.1.1 The cross-dimension of the wire loop is to be 50 6 5mm 134618in.1This test method is under the jurisdiction ofASTM Committee D08 on Roofingand Waterproofing and is the direct responsibility of Subcommittee D08.02 on SteepRoofing Products and Assemblies.Current edition approved Dec.15,2011.Published January 20112.Originallyapproved in 1959.Last previous edition approved in 2011 as D1670 04(2011)1.DOI:10.1520/D1670_D1670M-11.2For 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.3The sole source of supply of the apparatus known to the committee at this timeis Electrotechnic Model BD-40B Spark Generator,available from Electro-TechnicProducts Co.,4642 N.Ravenswood Ave.,Chicago,IL 60642.If you are aware ofalternative suppliers,please provide this information to ASTM Headquarters.Yourcomments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.1.2 The device is capable of delivering a 5-kV peakvoltage and of operating at 60 Hz.5.2 Photographic EquipmentA supply of sheets of mattesurface,regular weight,photocopy paper4or linagraphic papercut to the dimensions of the test panel,developer,and fixingchemicals.5.3 Counting Grid,as shown in Fig.2.Photocopy the gridon a transparency film that is suitable for use with plain papercopiers.Trim the outside edges to the exact dimensions of thetest panel making sure that the grid and the bituminous film onthe test panel are aligned.Outside dimensions,mm in.69.8 by 149.1 234by 578 orpanel sizeGrid dimensions,mm in.47.6 by 123.8 178by 478Number of squares in