1、Designation: D1670/D1670M 11Standard 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
2、 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
3、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, eac
4、hsystem 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 esta
5、blish 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
6、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 (Fluorescent UV,Water Spray, and Condensation Method)3. Summary of Tes
7、t 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
8、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 bitu
9、minous 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, bu
10、t 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
11、-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 134 618 in.5.1.2 The device is capable of delivering a 5-kV peakvolt
12、age 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.1This test method is under the jurisdiction ofASTM Committee D08 on Roofingand Water
13、proofing 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
14、 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 t
15、imeis 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 t
16、he responsibletechnical committee,1which you may attend.4Thermal facsimile paper with ultra-high sensitivity rating has also been foundsatisfactory for the same purpose. This paper is available nationwide from officesupply stores or catalogs.1Copyright ASTM International, 100 Barr Harbor Drive, PO B
17、ox C700, West Conshohocken, PA 19428-2959, United States.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
18、 onthe test panel are aligned.Outside dimensions, 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
19、 accordance with Practice D1669.7. Calibration 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 accordan
20、ce with requirements of Practice D1435at 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 D4798 or D4799. The prac-tice used and the s
21、pecific test condition selected from thepractice shall be by agreement between the interested parties.8.2.1 The two laboratory Practices D4798 and D4799 utilizelight sources with very different emission characteristics.Therefore, the practices may be expected to produce differenttest results. In add
22、ition, the alternate test conditions in each ofthe practices may also be expected to produce different testresults. Therefore, the report of time to failure must beaccompanied by reference to the practice used for exposure andthe specific test conditions.9. Detection of Cracks in Weathered Film9.1 A
23、t the end of an exposure period, 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 shouldbe
24、 passed over the complete surface of the bituminous film in5 to 10 s. The number of sparks 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 thespecim
25、ens showing sparking in 15 or more positions. Place oneof the photocopy sheets or linagraphic paper (cut to the exactFIG. 1 FeelerFIG. 2 Counting GridD1670/D1670M 112dimensions of the test panel) emulsion side down on the panel,making sure that the sheet and the panel are aligned, and passthe test f
26、eeler of the spark gap instrument over the back of thepaper.5The complete passage from top to bottom shall bewithin 5 to 10 s. Stroke 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 ordinaryphotograph
27、ic print.9.3 Cover each photograph with the transparent countinggrid so that the outer dimensions of the grid and the outerdimensions 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 followi
28、ngthe guidelines shown in Fig. 3.9.4 Continue the exposure of the panels until sparkingoccurs in at least 26 grid squares.9.5 Designate 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 ise
29、quivalent to a 10 % failure.10. Report10.1 Report the following information:10.1.1 Complete identification of the test material andcontrol 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,1
30、0.1.3 The exposure practice and cycle (conditions) used todegrade specimens,10.1.4 Any deviation from the standard test conditionsspecified in the exposure practice,10.1.5 Any additional report requirements listed in theexposure practice, and10.1.6 The exposure time after which sparkthrough pointsfi
31、rst occurred in 26 of the grid squares in each of the replicatespecimens and average of the replicates.11. Precision611.1 The following criterion shall be used for judging theacceptability of results (95 % probability):11.1.1 The values reported by each of two laboratories,representing the arithmeti
32、c average of duplicate determina-tions, shall not be considered suspect unless the reportedcounts differ by more than 19 %.12. Keywords12.1 accelerated weathering; bituminous materials; failureend point; outdoor weathering5A discussion of the photographic method of recording failures is given in “AN
33、ew Method for Evaluating Failure of Bituminous Materials Due to Weathering,”by Hunter, J. B., Gezemski, F. C., and Laskaris, L., ASTM 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:D08-1
34、009.FIG. 3 Guidelines to Determine Cracks (Spots) Weathered Bituminous FilmsD1670/D1670M 113ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determinatio
35、n of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.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 withdra
36、wn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your c
37、omments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown 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
38、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 114
