1、Designation: D 1670 04Standard Test Method forFailure End Point in Accelerated and Outdoor Weathering ofBituminous Materials1This standard is issued under the fixed designation D 1670; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 crac
3、king ofbituminous materials undergoing accelerated or outdoor weath-ering on electrically conductive backings.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety co
4、ncerns, 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:2D 529 Practice for Enclosed Carbon-Ar
5、c Exposures of Bi-tuminous MaterialsD 1435 Practice for Outdoor Weathering of PlasticsD 1669 Practice for Preparation of Test Panels for Acceler-ated and Outdoor Weathering of Bituminous MaterialsD 4798 Practice for Accelerated Weathering Test Condi-tions and Procedures for Bituminous Materials (Xen
6、on-Arc Method)D 4799 Practice for Accelerated Weathering Test Condi-tions and Procedures for Bituminous Materials (Fluores-cent 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 ba
7、ck 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 squarescon
8、taining 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 accurate
9、ly 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
10、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. Otherconfiguration
11、s 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 peakvoltage and of operating at 60 Hz.5.2 Photographic EquipmentA supply of sheets of mattesurface, regular weight, pho
12、tocopy 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 paper1This test method is under the jurisdiction of ASTM Committee D08 on Roofi
13、ngand Waterproofing and is the direct responsibility of Subcommittee D08.02 onPrepared Roofings, Shingles, and Siding Materials.Current edition approved May 1, 2004. Published May 2004. Originallyapproved in 1959. Last previous edition approved in 2003 as D 1670 98 (2003).2For referenced ASTM standa
14、rds, 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 Electr
15、otechnic 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 responsib
16、letechnical 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 Box C700, Wes
17、t Conshohocken, PA 19428-2959, United States.copiers. 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 (234 by 578) or panel sizeGrid dimensions, mm (in.) 47.6 by
18、123.8 (178 by 478)Number of squares in grid 260 (10 by 26)Size of squares, mm (in.) 4.76 (316)6. Test Specimens6.1 Unless otherwise agreed upon, test specimens shall beprepared in accordance with Practice D 1669.7. Calibration of the Spark-Generating Apparatus7.1 VoltageCalibrate the peak voltage of
19、 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 PracticeD 1435 at a site, rack angle and backing to be agreed on by theinterested parties.8.2 La
20、boratory Accelerated WeatheringExpose speci-mens to laboratory accelerated weathering in accordance withprocedures described in Practice D 529, D 4798, or D 4799.The practice used and the specific test condition selected fromthe practice shall be by agreement between the interestedparties.8.2.1 The
21、three laboratory Practices D 529, D 4798, andD 4799 utilize light sources with very different emissioncharacteristics. Therefore, the practices may be expected toproduce different test results. In addition, the alternate testconditions in each of the practices may also be expected toproduce differen
22、t 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 period, remove the test panelfrom the weathering unit or outdoor exposure s
23、ite. 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 passed over the complete surface of the bituminous film in5 to 10 s. The number of sparks should be
24、 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 linagraphic paper
25、(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 passFIG. 1 FeelerFIG. 2 Counting GridD1670042the test feeler of the spark gap instrument over the back of thepaper.5The complete passage from top to bottom shall b
26、ewithin 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 ordinaryphotographic print.9.3 Cover each photograph with the transparent countinggrid so that the outer dimensions of the gri
27、d 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 followingthe guidelines shown in Fig. 3.9.4 Continue the exposure of the panels until sparkingoccurs in at least 26
28、 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 isequivalent to a 10 % failure.10. Report10.1 Report the following information:10.1.1 Complete identification o
29、f 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,10.1.3 The exposure practice and cycle (conditions) used todegrade specimens,10.1.4 Any deviation from the st
30、andard 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 pointsfirst occurred in 26 of the grid squares in each of the replicatespecimens and average of the replicates.11. P
31、recision611.1 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 arithmetic average of duplicate determina-tions, shall not be considered suspect unless the reportedcounts differ by
32、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 “ANew Method for Evaluating Failure of Bituminous Materials Due to Weathering,”by Hunter, J. B., Gezemski, F. C
33、., 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: D08-1009.FIG. 3 Guidelines to Determine Cracks (Spots) Weathered Bituminous FilmsD1670043ASTM International tak
34、es 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 determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own re
35、sponsibility.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 addres
36、sed 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 comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at th
37、e 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 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).D1670044
