1、Designation: D2746 07 (Reapproved 2013)D2746/D2746M 18Standard Test Method forStaining Tendency of Asphalt (Stain Index)1This standard is issued under the fixed designation D2746;D2746/D2746M; the number immediately following the designation indicatesthe year of original adoption or, in the case of
2、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 determination of the staining tendency of asphalt and the assignment
3、 of a stain indexproportional to the extent of staining observed.1.2 This test method is applicable to asphalts having ring-and-ball softening points of 85C (185F)185F or greater.NOTE 1This test method may be modified for use with other bituminous materials with softening points less than 85C (185F)
4、185F by using adifferent temperature than specified in Section 7 by agreement of the interested parties. The report of results from such a test may cite this method butmust clearly state the temperature employed in the exception and acknowledge that the interpretation of results in Section 9 and the
5、 precision and biasstated in Section 10 may not apply.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as the standard. The values inparentheses are for information only.stated in each system may not be exact equivalents; therefore, each system shall be used
6、independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.4 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of theuser of this standard to establish appropriate safety s
7、afety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Developmen
8、t of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D36D36/D36M Test Method for Softening Point of Bitumen (Ring-and-Ball Apparatus)D140D140/D140M Practice for Sampling A
9、sphalt MaterialsE230/E230M Specification for Temperature-Electromotive Force (emf) Tables for Standardized ThermocouplesE1137/E1137M Specification for Industrial Platinum Resistance ThermometersE2251 Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids3. Summary of T
10、est Method3.1 A horizontal disc of asphalt, cast in a brass retaining ring, is placed on a sheet of filter paper supported on a flat plate andheated at 80C (175F)175F for 120 h. The diameter of the resulting stained circle on the paper is compared to the insidediameter of the brass ring to determine
11、 the staining characteristic of the asphalt. The stain index is the difference between thediameter of the stained circle and the initial disc diameter measured to the nearest 0.5 mm (164 in.).in.4. Significance and Use4.1 This test method measures the tendency for oil components to separate spontane
12、ously from asphalt. The separation of oilcomponents can cause staining in asphalt roofing products and adjacent materials in storage and use.4.2 The stain index is related to the thermal stability of the asphalt. Higher stain index values indicate lower stability and greatertendency for staining.1 T
13、his test method is under the jurisdiction of ASTM Committee D08 on Roofing and Waterproofing and is the direct responsibility of Subcommittee D08.02 on SteepRoofing Products and Assemblies.Current edition approved May 1, 2013Nov. 1, 2018. Published May 2013December 2018. Originally approved in 1991.
14、 Last previous edition approved in 20072013 asD2746 07. 07 (2013). DOI: 10.1520/D2746-07R13.10.1520/D2746_D2746M-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to t
15、he standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes a
16、ccurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United
17、States14.3 Use this procedure to determine the staining tendency of asphalt and to compare the results against a material for which thestaining tendency is known.5. Apparatus5.1 RingsSquare shouldered brass retaining rings conforming to the dimensions required for use in the ring-and-ball softeningp
18、oint apparatus (see Fig. 1 (a) 1(a) of Test Method D36D36/D36M).5.1.1 The inside diameter of the ring to be placed in contact with the filter paper during the test is 16 mm (4064 in.).in.NOTE 2This test method depends on accurate measurement of diameter and precise alignment of the face and rim of t
19、he ring on a flat surface.Therefore, deformed rings must not be used.5.2 Pouring PlateA flat, smooth, brass plate approximately 50 by 75 mm (22 by 3 in.).in.5.3 PaperFilter paper of the standard double acid-washed analytical grade.35.3.1 The filter paper must be of sufficient area to accommodate the
20、 number of samples and the known material arranged asdescribed in 7.3.5.4 Support PlateA flat, clean, smooth metal plate approximately 1.5 mm (116 in.)in. thick and area at least sufficient tosupport the size of filter paper being used.5.5 OvenA constant temperature oven capable of maintaining the t
21、est temperature of 80C (175F)175F within 61C(62F).62F.5.6 ThermometerThermometric Device An ASTM thermometer having a range from 20 to 102C (5 to 215F), andconforming to the requirements for Thermometer S12C (or S12F) as prescribed in Specification The E2251.As an alternative, anyother thermometric
22、device used shall be at least: (1) of equal accuracy to that of the S12C (or S12F) thermometer specified inSpecification E2251, (2) capable of indicating temperature to within 1C (2F),2F, and (3) stable to within 1C (2F)2F forthe duration of the exposure.5.6.1 When used, platinum resistance thermome
23、ters shall be in accordance with the requirements of Specification E1137/E1137M.5.6.2 When used, thermocouples shall be in accordance with the requirements of Specification E230/E230M.5.7 Measuring RuleA steel rule graduated in 0.5 mm (64ths64ths of an inch).inch.5.7.1 Hole TemplateA metal or plasti
24、c template provided with holes of diameter from 16 to 24 mm (4064 to 6064 in.)in. in0.5-mm (164-in.)-in. increments may be used as an alternative to the steel rule to measure the diameter of the stain circle afterthe test.6. Sampling6.1 Sample the material in accordance with Practice D140D140/D140M.
25、7. Procedure7.1 Melt the asphalt sample and pour into the preheated brass softening point ring, allow to cool, and trim off the excess asphaltfrom each face of the ring as described in Test Method D36D36/D36M.7.1.1 It is important that the lower face and rim of the ring (16-mm (4064-in.)-in. inside
26、diameter) be clean and that the asphaltdisc completely fill the ring and be flush with the lower face. There should be no trace of any release agent which may have beenused on the pouring plate (see Test Method D36D36/D36M) on either the lower face of the ring or the asphalt.7.2 Place the filter pap
27、er on the flat support plate and put the filled and trimmed softening point rings on the paper with the16-mm (4064-in.)-in. diameter asphalt disc face in contact with the paper. Each ring should be no closer than 40 mm (1.5 in.)1.5in. from the edge of the filter paper or from another ring.7.2.1 The
28、known material (Note 3) must be placed on the same piece of filter paper and support plate as the sample(s) beingtested.NOTE 3The “known” material for the purpose of this test is a material whose staining tendency is known to the investigator and which is used tocompare with the material being teste
29、d (see also Note 6).7.2.2 Identify each asphalt sample and known material by appropriately marking the filter paper in pencil near each ring.7.3 Place the entire assembly on the support plate in the oven, preheated to 8061C (17517562F),2F, and allow to remainat that temperature for 120 6 1 h.7.4 Rem
30、ove the assembly on the support plate from the oven and allow to cool to room temperature (about 24C(75F).75F).3 The sole source of supply of the paper known to the committee at this time is Whatman No. 40 filter paper, available from laboratory supply and service companies.If you are aware of alter
31、native suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee,1 which you may attend.D2746/D2746M 1827.5 Remove the ring and the asphalt disc from the filter paper taking care
32、to avoid tearing of the paper.7.6 Determine and record the average of three measurements, taken at about 120 apart, of the diameter of the stained circleon the filter paper expressed numerically in 0.4-mm units (64ths64ths of an inch)inch to the nearest 0.4 mm (164 in.)in. usinga steel rule.7.6.1 Al
33、ternatively, use the hole template and determine the diameter of the hole which best fits the stained circle on the filterpaper and record the result numerically in 0.4-mm units (64ths64ths of an inch)inch to the nearest 0.4 mm (164 in.).in.8. Calculation and Interpretation of Results8.1 Subtract th
34、e initial diameter of the asphalt disc expressed numerically in 0.4-mm units (64ths64ths of an inch),inch, thatis, 40 from the average, or best fit, diameter of the stained circle on the filter paper expressed numerically in 0.4-mm units(64ths64ths of an inch)inch to obtain the stain index.NOTE 4If
35、the dimensional measurements have been made in metric units, the average diameter must be converted to inch units at this point in orderto compute the numerical value for stain index which is derived from the diameter expressed numerically in 64ths of an inch.NOTE 5Example: If the average, or best f
36、it, diameter of the stained circle on the filter paper is 19.5 mm (4964 in.),in., then the stainindex = 49 40 = 9.8.2 Interpretation of ResultsThe following ranges of stain index have been determined to represent the staining tendency ofasphalts used in the production of asphalt roofing shingles.Sta
37、in Index Staining Tendency0 to 10 low10 to 20 moderateGreater than 20 highThe staining tendency in roofing products is strongly influenced by storage conditions especially temperature and time, by thepressure generated in stacked material from the mass of material in the overlying stack, and by the
38、nature, amount, and distributionof backsurfacing material.9. Report9.1 Report the stain index value determined as in 8.1.10. Precision and Bias10.1 Results of two properly conducted tests by a single operator should not differ by more than two stain index numbers forasphalts with stain index of ten
39、or less nor by more than three stain index numbers for asphalts with stain index greater than ten.10.2 Results of two properly conducted tests on the same sample of asphalt between different laboratories should be consideredsuspect if they differ by more than four stain index numbers when one of the
40、 values is ten or less, or if they differ by more thansix stain index numbers when both values are greater than ten.10.3 A test should be considered suspect if the stain index obtained for the known material differs by more than two from theexpected value for materials with stain index of ten or les
41、s, or by more than three for materials with stain index greater than 10.NOTE 6The major cause of bias error in this test method has been found to be inadvertent changes in the temperature of the test oven. This is theprimary reason for suggesting comparison to a material with known staining tendency
42、 in the performance of the test.11. Keywords11.1 asphalt; stain index; stainingASTM 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 determination of the vali
43、dity 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 withdrawn.Your comme
44、nts 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 comments have n
45、ot 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 or multiple co
46、pies) 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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 183
