1、Designation: D 5081 90 (Reapproved 2005)Standard Test Method forAggregate Layer Hiding Power1This standard is issued under the fixed designation D 5081; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber 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 measures the quantity of aggregateneeded to provide an opaque layer under laboratory conditions.Aggregate size Numbers
3、 1 through 8, as listed in ClassificationD 448, may be tested.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 concerns, if any, associated with its use. It is t
4、heresponsibility 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:2C 702 Practice for Reducing Samples of Aggregate toTesting SizeD75 Practice for Sampl
5、ing AggregatesD 448 Classification for Sizes of Aggregate for Road andBridge ConstructionD 1079 Terminology Relating to Roofing, Waterproofing,and Bituminous Materials3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, see Terminology D 1079.4. Significance and Use4.1 One
6、of the functions of a roofing aggregate is to shieldthe roofing membrane from sunlight that may be destructive tothe roofing membrane. This test method measures the quantityof gravel needed to exclude light under arbitrary laboratoryconditions. This test method need not be performed if theroofing me
7、mbrane is not affected by light exposure.5. Apparatus5.1 Exposure Box, 300-mm2(12-in.2) 6 1 % tray, 90 mm(3.6 in.) minimum deep with an opaque lid.5.2 Light Source150-W floodlight with stand.5.3 Counting TemplateA clear plastic mask with 100-mm2(4-in.2) grid of lines 10 mm (0.4 in. ) apart to result
8、 in 100counting cells.5.4 Light Sensitive PaperRapid printing opaque diazopapers for use in diazo blueline printing machines.5.5 Sample Splitter, riffle type.5.6 Balance, 30-kg (66-lb) capacity, sensitive to 3 3 103%of the capacity.5.7 Diazo Printing Machine.6. Sampling6.1 Follow the sampling recomm
9、endations of Practice D75.7. Procedure7.1 For Roofing BallastFractionate the aggregate, dried to110C (230F ) to constant weight, using a sample splitter, untila 25-kg (55-lb) sample is obtained. Riffle out 2.3-kg (5.1-lb),4.5-kg (9.9-lb), 6.8-kg (15.0-lb), and 9-kg (20.0-lb) 61%specimens in accordan
10、ce with Practice C 702.7.2 For Builtup Roofing AggregateFractionate the driedaggregate sample, using the sample splitter, until a 6-kg(13.4-lb) sample is obtained. Riffle out 1.394-kg (3.073-lb),1.858-kg (4.096-lb), and 2.323-kg (5.12-lb) 61 % specimensin accordance with Practice C 702. These specim
11、ens representaggregate application rates of 15 kg/m2(3.1 lb/ft2).1This test method is under the jurisdiction ofASTM Committee D08 on Roofingand Waterproofing and is the direct responsibility of Subcommittee D08.03 onSurfacing and Bituminous Materials for Membrane Waterproofing and Built-upRoofing.Cu
12、rrent edition approved Nov. 1, 2005. Published November 2005. Originallyapproved in 1990. Last previous edition approved in 1999 as D 5081 90 (1999)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStan
13、dards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.3 Cut a sheet of light sensitive paper to cover the bottomof the exposure box. Place the pape
14、r in the box. Position thelight source over the center of the box with 610 mm (24 in.)between the bottom of the bulb and the paper. Cover the paperuniformly with the test aggregate.7.4 Turn the light source on for 10 min.7.5 Remove the aggregate and develop the light sensitivepaper in a “blue ray” o
15、r other appropriate printing machine.7.6 Expose and record on light sensitive paper the lighttransmitted through the weighed aggregate specimens.7.7 Estimate the light pigmented areas on the print, place thecounting template over a representative area of each print, andcount the number of cells (the
16、 percent) that fall on light areas.8. Calculation8.1 The number of template cells that show no light pen-etration is the percent opacity.8.2 Assume a linear relationship between percent opacityand application rate. Calculate the quantity of aggregateneeded to obtain 100 % opacity.9. Report9.1 Report
17、 the source, size number, and type of eachsample.9.2 Report the percent opacity (from 8.1) and the applica-tion rate of the aggregate.9.3 Attach a clearly labeled copy of each print (from 7.5).9.4 Report the quantity of ballast needed to obtain 100 %opacity.10. Precision and Bias10.1 The linear rela
18、tionship assumed between applicationrate and opacity (used in 7.4) is justified by round-robin testingwhere the least squares linear regression coefficient averaged0.94, with a range from 0.82 to 0.99.10.2 PrecisionBoth the multilaboratory and the within-laboratory standard deviations have been foun
19、d to be 2.8 % inpercent opacity. Therefore, results of two properly conductedtests should not differ by more than 8 % opacity. The standarddeviation of the quantity of aggregate to obtain completeopacity is 0.1 kg/m2(0.02 lb/ft2) between laboratories andwithin a laboratory. Therefore, results of two
20、 properly con-ducted tests should not differ by more than 0.30 kg/m2(0.061lb/ft2).10.3 BiasThe procedure in this test method for hidingpower has no bias because the quantity of aggregate needed toexclude sunlight is defined by this test method.11. Keywords11.1 aggregate; ballast; bituminous; roofing
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22、 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 comments are invited either for revision of this standard or for additional standar
23、dsand 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 not received a fair hearing you shouldmake your views known to the ASTM Committ
24、ee 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 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).D 5081 90 (2005)2
