1、Designation:D475112Standard Test Method forDetermining Apparent Opening Size of a Geotextile1This standard is issued under the fixed designation D4751;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number
2、 in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers the determination the apparentopenin
3、g size(AOS)of a geotextile by sieving glass beadsthrough a geotextile.1.2 This test method shows the values in both SI units andinch-pound units.SI units is the technically correct name forthe system of metric units known as the International System ofUnits.Inch-pound units is the technically correc
4、t name for thecustomary units used in the United States.The values ininch-pound units are provided for information only.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 establish appro-priat
5、e safety and health practices and determine the applica-bility of regulatory requirements prior to use.2.Referenced Documents2.1 ASTM Standards:2C136 Test Method for Sieve Analysis of Fine and CoarseAggregatesD1776 Practice for Conditioning and Testing TextilesD4238 Test Method for Electrostatic Pro
6、pensity of Textiles(Withdrawn 1996)3D4354 Practice for Sampling of Geosynthetics and RolledErosion Control Products(RECPs)for TestingD4439 Terminology for GeosyntheticsE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3.Terminology3.1 Definitions:For general geosynthetics terms used in
7、 thisstandard,refer to Terminology D4439.3.2 Definitions:3.2.1 apparent opening size(AOS),O95,nfor a geotextile,a property that indicates the approximate largest particle thatwould effectively pass through the geotextile.4.Summary of Test Method4.1 A geotextile specimen is placed in a sieve frame,an
8、dsized glass beads are placed on the geotextile surface.Thegeotextile and frame are shaken laterally so that the jarringmotion will induce the beads to pass through the test specimen.The procedure is repeated on the same specimen with varioussize glass beads until its apparent opening size has beend
9、etermined.5.Significance and Use5.1 Using a geotextile as a medium to retain soil particlesnecessitates compatibility between it and the adjacent soil.Thistest method is used to indicate the apparent opening size in ageotextile,which reflects the approximate largest openingdimension available for so
10、il to pass through.5.2 Test Method D4751 for the determination of openingsize of geotextiles is acceptable for testing of commercialshipments of geotextiles.Current estimates of precision,be-tween laboratories,are being established.5.2.1 In case of a dispute arising from differences inreported test
11、results when using Test Method D4751 foracceptance testing of commercial shipments,the purchaser andthe supplier should conduct comparative tests to determine ifthere is a statistical bias between their laboratories.Competentstatistical assistance is recommended for the investigation ofbias.As a min
12、imum,the two parties should take a group of testspecimens that are homogeneous as possible and that are froma lot of material of the type in question.The test specimensshould then be randomly assigned in equal numbers to eachlaboratory for testing.The average results from the twolaboratories should
13、be compared using Students t-test forunpaired data and an acceptable probability level chosen by thetwo parties before the testing is begun.If a bias is found,eitherits cause must be found and corrected or the purchaser and thesupplier must agree to interpret future test results in the light ofthe k
14、nown bias.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.03 on Perme-ability and Filtration.Current edition approved July 1,2012.Published August 2012.Originallyapproved in 1993.Last previous version approved in
15、2004 as D4751 04.DOI:10.1520/D4751-12.2For referenced ASTM standards,visit 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 last approved version o
16、f this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Apparatus6.1 Mechanical Sieve ShakerA mechanical sieve shaker,which imparts lateral and vertical motion to the sieve,causingthe particles thereon to bounce and turn so as to presentdifferent orientations to the sieving surface,should be used.The sieve shaker should be a constant frequency deviceutilizing a tapping arm to impart th