1、Designation: D1670/D1670M 04 (Reapproved 2011)1Standard 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 adopt
2、ion 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.1NOTEUnits information was editorially revised in July 2011.1. Scope1.1 This test met
3、hod 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 standar
4、d. 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, associ
5、ated 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:2D529 Practice for Enclosed Carbon-Arc Exposures of Bi-tumin
6、ous MaterialsD1435 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 f
7、or Accelerated Weathering Test Conditionsand Procedures for Bituminous Materials (Fluorescent UV,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 se
8、nsitivity 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 count
9、ed 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 vi
10、sually.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 (
11、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 th
12、e followingconditions: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 July 1, 2011. Published July 2011. Originally approvedin 1959. L
13、ast previous edition approved in 2004 as D1670 04. DOI: 10.1520/D1670_D1670M-04R11E01.2For 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
14、 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 thi
15、s information to ASTM Headquarters. Yourcomments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.1.1 The cross-dimension of
16、 the wire loop is to be 50 6 5mm 134 618 in.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
17、 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 di
18、mensions, mm in. 69.8 by 149.1 234 by 578 or panel sizeGrid dimensions, mm in. 47.6 by 123.8 178 by 478Number of squares in grid 260 (10 by 26)Size of squares, mm in. 4.76 3166. Test Specimens6.1 Unless otherwise agreed upon, test specimens shall beprepared in accordance with Practice D1669.7. Calib
19、ration of the Spark-Generating Apparatus7.1 VoltageCalibrate the peak voltage of the spark gen-erator to 5 6 0.5 kV according to the manufacturers instruc-tions.8. Procedures for Weathering8.1 Outdoor WeatheringExpose specimens to outdoorweathering in accordance with requirements of Practice D1435at
20、 a site, rack angle and backing to be agreed on by theinterested parties.8.2 Laboratory Accelerated WeatheringExpose speci-mens to laboratory accelerated weathering in accordance withprocedures described in Practice D529, D4798,orD4799. Thepractice used and the specific test condition selected from
21、thepractice shall be by agreement between the interested parties.8.2.1 The three laboratory Practices D529, D4798, andD4799 utilize light sources with very different emissioncharacteristics. Therefore, the practices may be expected toproduce different test results. In addition, the alternate testcon
22、ditions in each of the practices may also be expected toproduce different test results. Therefore, the report of time tofailure must be accompanied by reference to the practice usedfor exposure and the specific test conditions.9. Detection of Cracks in Weathered Film9.1 At the end of an exposure per
23、iod, remove the test panelfrom the weathering unit or outdoor exposure site. Allow thepanels to dry thoroughly and bring them to room temperature.9.2 Ground each panel at the back surface or the conductiveedge. The test feeler (see Fig. 1) of the spark instrument should4Thermal facsimile paper with
24、ultra-high sensitivity rating has also been foundsatisfactory for the same purpose. This paper is available nationwide from officesupply stores or catalogs.FIG. 1 FeelerFIG. 2 Counting GridD1670/D1670M 04 (2011)12be passed over the complete surface of the bituminous film in5 to 10 s. The number of s
25、parks should be noted during thepass. If the number of sparkthrough points on any panel is lessthan 15, at least316 in. apart, set the panel aside for re-exposure. Make a photographic record of the rest of thespecimens showing sparking in 15 or more positions. Place oneof the photocopy sheets or lin
26、agraphic paper (cut to the exactdimensions of the test panel) emulsion side down on the panel,making sure that the sheet and the panel are aligned, and passthe test feeler of the spark gap instrument over the back of thepaper.5The complete passage from top to bottom shall bewithin 5 to 10 s. Stroke
27、the feeler across the surface from sideto side to ensure complete recording of all cracks. Then, ifnecessary, develop the paper in the manner of an ordinaryphotographic print.9.3 Cover each photograph with the transparent countinggrid so that the outer dimensions of the grid and the outerdimensions
28、of the photographic paper are aligned, and theinner grid is centered in the area of the bituminous material.Record the number of squares in which spots appear followingthe guidelines shown in Fig. 3.9.4 Continue the exposure of the panels until sparkingoccurs in at least 26 grid squares.9.5 Designat
29、e the failure end point of the specimen as theexposure time after which sparkthrough points first occurred in26 of the grid squares. This number of failure points isequivalent to a 10 % failure.10. Report10.1 Report the following information:10.1.1 Complete identification of the test material andcon
30、trol material, if used, including the type, amount and typeof mineral filler, source, and manufacturers code number,10.1.2 Thickness, width, and length of specimens,10.1.3 The exposure practice and cycle (conditions) used todegrade specimens,10.1.4 Any deviation from the standard test conditionsspec
31、ified in the exposure practice,10.1.5 Any additional report requirements listed in theexposure practice, and10.1.6 The exposure time after which sparkthrough pointsfirst occurred in 26 of the grid squares in each of the replicatespecimens and average of the replicates.11. Precision611.1 The followin
32、g criterion shall be used for judging theacceptability of results (95 % probability):11.1.1 The values reported by each of two laboratories,representing the arithmetic average of duplicate determina-tions, shall not be considered suspect unless the reportedcounts differ by more than 19 %.12. Keyword
33、s12.1 accelerated weathering; bituminous materials; failureend point; outdoor weathering5A discussion of the photographic method of recording failures is given in “ANew Method for Evaluating Failure of Bituminous Materials Due to Weathering,”by Hunter, J. B., Gezemski, F. C., and Laskaris, L., ASTM
34、STP 94,ASTM, 1949, pp.144152.6A copy of the research report used to develop the precision statement isavailable from ASTM International Headquarters. Request RR:D08-1009.FIG. 3 Guidelines to Determine Cracks (Spots) Weathered Bituminous FilmsD1670/D1670M 04 (2011)13ASTM International takes no positi
35、on respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility
36、.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM
37、International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address sh
38、own below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D1670/D1670M 04 (2011)14
