1、Designation:D274607(Reapproved 2013)Standard Test Method forStaining Tendency of Asphalt(Stain Index)1This standard is issued under the fixed designation D2746;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision
2、.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the stain-ing tendency of asphalt and the assignment of a stain indexproportional to the ex
3、tent of staining observed.1.2 This test method is applicable to asphalts having ring-and-ball softening points of 85C(185F)or greater.NOTE1This test method may be modified for use with otherbituminous materials with softening points less than 85C(185F)byusing a different temperature than specified i
4、n Section 7 by agreement ofthe interested parties.The report of results from such a test may cite thismethod but must clearly state the temperature employed in the exceptionand acknowledge that the interpretation of results in Section 9 and theprecision and bias stated in Section 10 may not apply.1.
5、3 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.1.4 This standard does not purport to address the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety an
6、dhealth practices and determine the applicability of regulatorylimitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D36 Test Method for Softening Point of Bitumen(Ring-and-Ball Apparatus)D140 Practice for Sampling Bituminous MaterialsE2251 Specification for Liquid-in-Glass ASTM Thermom
7、-eters with Low-Hazard Precision Liquids3.Summary of Test Method3.1 A horizontal disc of asphalt,cast in a brass retainingring,is placed on a sheet of filter paper supported on a flat plateand heated at 80C(175F)for 120 h.The diameter of theresulting stained circle on the paper is compared to the in
8、sidediameter of the brass ring to determine the staining character-istic of the asphalt.The stain index is the difference betweenthe diameter of the stained circle and the initial disc diametermeasured to the nearest 0.5 mm(164in.).4.Significance and Use4.1 This test method measures the tendency for
9、 oil compo-nents to separate spontaneously from asphalt.The separation ofoil components can cause staining in asphalt roofing productsand adjacent materials in storage and use.4.2 The stain index is related to the thermal stability of theasphalt.Higher stain index values indicate lower stability and
10、greater tendency for staining.4.3 Use this procedure to determine the staining tendency ofasphalt and to compare the results against a material for whichthe staining tendency is known.5.Apparatus5.1 RingsSquare shouldered brass retaining rings con-forming to the dimensions required for use in the ri
11、ng-and-ballsoftening point apparatus(see Fig.1(a)of Test Method D36).5.1.1 The inside diameter of the ring to be placed in contactwith the filter paper during the test is 16 mm(4064in.).NOTE2This test method depends on accurate measurement ofdiameter and precise alignment of the face and rim of the
12、ring on a flatsurface.Therefore,deformed rings must not be used.5.2 Pouring Plate A flat,smooth,brass plate approxi-mately 50 by 75 mm(2 by 3 in.).5.3 PaperFilter paper of the standard double acid-washedanalytical grade.35.3.1 The filter paper must be of sufficient area to accom-modate the number of
13、 samples and the known materialarranged as described in 7.3.5.4 Support Plate A flat,clean,smooth metal plate ap-proximately 1.5 mm(116in.)thick and area at least sufficient tosupport the size of filter paper being used.1This test method is under the jurisdiction ofASTM Committee D08 on Roofingand W
14、aterproofing and is the direct responsibility of Subcommittee D08.02 onSteep Roofing Products and Assemblies.Current edition approved May 1,2013.Published May 2013.Originallyapproved in 1991.Last previous edition approved in 2007 as D2746 07.DOI:10.1520/D2746-07R13.2For referenced ASTM standards,vis
15、it 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 paper known to the committee at this time isWhatman No.40 filter p
16、aper,available from laboratory supply and servicecompanies.If you are aware of alternative suppliers,please provide this informationto ASTM International Headquarters.Your comments will receive careful consid-eration at a meeting of the responsible technical committee,1which you may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.5 OvenA constant temperature oven capable of main-taining the test temperature of 80C(175F)within
