1、Designation: D5081/D5081M 90 (Reapproved 2011)1Standard Test Method forAggregate Layer Hiding Power1This standard is issued under the fixed designation D5081/D5081M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEUnits information was editorially corrected in January 2012.1. Scope1.1 This test method measures the quantity of aggregateneeded
3、to provide an opaque layer under laboratory conditions.Aggregate size Numbers 1 through 8, as listed in ClassificationD448, may be tested.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 equivalent
4、s; therefore, eachsystem 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
5、 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:2C702 Practice for Reducing Samples of Aggregate to Test-ing SizeD75 Practice for Sampling AggregatesD448 Classification f
6、or Sizes of Aggregate for Road andBridge ConstructionD1079 Terminology Relating to Roofing and Waterproofing3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, see Terminology D1079.4. Significance and Use4.1 One of the functions of a roofing aggregate is to shieldthe roof
7、ing 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 membrane is not affected by light exposure.5. Apparatus5.1 Exp
8、osure Box, 300-mm212-in.2 6 1 % tray, 90 mm3.6 in. minimum deep with an opaque lid.5.2 Light Source150-W floodlight with stand.5.3 Counting TemplateA clear plastic mask with 100-mm24-in.2 grid of lines 10 mm 0.4 in. apart to result in 100counting cells.5.4 Light Sensitive PaperRapid printing opaque
9、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 recommendations of Practice D75.7. Procedure7.1 For Roofing BallastFractionat
10、e 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 accordance with Practice C702.7.2 For Builtup Roofing AggregateFractionate the driedaggregat
11、e sample, using the sample splitter, until a 6-kg13.4-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 C702. These specimens representaggregate application rates of 15 kg/m23.1 lb/ft2.7.3 Cut a sheet of light sensit
12、ive paper to cover the bottomof the exposure box. Place the paper in the box. Position thelight source over the center of the box with 610 mm 24 in.1This test method is under the jurisdiction ofASTM Committee D08 on Roofingand Waterproofing and is the direct responsibility of Subcommittee D08.03 onS
13、urfacing and Bituminous Materials for Membrane Waterproofing and Built-upRoofing.Current edition approved Nov. 1, 2011. Published January 2012. Originallyapproved in 1990. Last previous edition approved in 2005 as D5081 90 (2005).DOI: 10.1520/D5081_D5081M-90R11E01.2For referenced ASTM standards, vis
14、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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2
15、959, United States.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” or other appropriate printing machine.7.6 Expose and record on light
16、 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 percent) that fall on light areas.8. Calculation8.1 The number of
17、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 the source, size number, and type of eachsample.9.2 Report the per
18、cent 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 relationship assumed between applicationrate and opacity (used in 7.4)
19、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 found to be 2.8 % inpercent opacity. Therefore, results of two properly
20、 conductedtests should not differ by more than 8 % opacity. The standarddeviation of the quantity of aggregate to obtain completeopacity is 0.1 kg/m20.02 lb/ft2 between laboratories andwithin a laboratory. Therefore, results of two properly con-ducted tests should not differ by more than 0.30 kg/m20
21、.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; roofingASTM International takes no position respecting the validity of any pat
22、ent 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 responsibility.This standard is subject to revision
23、 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 addressed to ASTM International Headquarters. Your comm
24、ents 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 the address shown below.This standard is copyrighte
25、d 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D5081/D5081M 90 (2011)12
