1、Designation:D5081/D5081M90(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 revisi
2、on.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.Scope1.1This test method measures the quantity of aggregateneeded to provide a
3、n 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 equivalents;therefore,eac
4、hsystem 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 standard to establis
5、h 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 ofAggregate to TestingSizeD75 Practice for Sampling AggregatesD448 Classification for Sizes of Aggregate for
6、 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 roofing membrane from sunlight t
7、hat 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 Exposure Box,300-mm212-in.2 6 1%tr
8、ay,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 diazopapers for use in diazo blueline
9、 printing machines.5.5 Sample Splitter,riffle type.5.6 Balance,30-kg 66-lb capacity,sensitive to 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 BallastFractionate the aggregate,dried to110C 230F to constan
10、t 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 driedaggregate sample,using the sample splitter,until a 6-kg13.
11、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 sensitive paper to cover the bottomof the exposure box.Place th
12、e paper in the box.Position the1This 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.Current edition approved Nov.1,2011.
13、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,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume i
14、nformation,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 light source over the center of the box with 610 mm 24 in.between the bottom of the bulb and the paper.Cover the pa
15、peruniformly 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 sensitive paper the lighttransmitted through the weighed aggregate specimens.7
16、.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 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 Repo
