1、Designation:D475104D475112 Standard Test Method for Determining Apparent Opening Size of a Geotextile 1 This standard is issued under the xed designation D4751; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revi
2、sion.Anumber in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. 1. Scope 1.1 This test method covers the determination the
3、 apparent opening size (AOS) of a geotextile by sieving glass beads through a geotextile. 1.2 This test method shows the values in both SI units and inch-pound units. SI units is the technically correct name for the system of metric units known as the International System of Units. Inch-pound units
4、is the technically correct name for the customary units used in the United States. The values in inch-pound units are provided for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this
5、 standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use. 2. Referenced Documents 2.1 ASTM Standards: 2 C136Test Method for Sieve Analysis of Fine and Coarse Aggregates D123Terminology Relating to Textiles D1776Practice fo
6、r Conditioning and Testing Textiles D4238Test Method for Electrostatic Propensity of Textiles (Withdrawn 1996) 3 D4354Practice for Sampling of Geosynthetics and Rolled Erosion Control Products(RECPs) for Testing D4439Terminology for Geosynthetics E11Specication for Woven Wire Test Sieve Cloth and Te
7、st Sieves 3. Terminology 3.1 Denitions: 3.1.1 apparentopeningsize(AOS),O 95 ,nforageotextile,apropertythatindicatestheapproximatelargestparticlethatwould effectively pass through the geotextile. 3.1.2 atmosphere for testing geosynthetics, nair maintained at a relative humidity between 50 to 70% and
8、a temperature of 216 2C (706 4F). 3.1.3 DiscussionThelaboratoryconditionsareveryimportanttotheAOStest.Forexample,excessivehumidity(above70%) can cause beads to stick together; while too low a relative humidity (below 50%) can result in an increase in static electricity. 3.1.4 geotechnics, nthe appli
9、cation of scientic methods and engineering principles to the acquisition, interpretation, and use of knowledge of materials of the earths crust to the solution of engineering problems. 3.1.5 DiscussionGeotechnics embraces the elds of soil mechanics, rock mechanics, and many of the engineering aspect
10、s of geology, geophysics, hydrology, and related sciences. 3.1.6 geotextile,nanypermeabletextilematerialusedwithfoundation,soil,rock,earth,oranyothergeotechnicalengineering related material as an integral part of a man-made project, structure, or system. 1 This test method is under the jurisdiction
11、of ASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35.03 on Permeability and Filtration. Current edition approved Nov. 1, 2004July 1, 2012. Published December 2004 August 2012. Originally approved in 1993. Last previous version approved in 2004 as D475199aD47510
12、4.(2004). DOI: 10.1520/D4751-04. 10.1520/D4751-12. 2 ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatserviceastm.org.For Annual Book ofASTM Standards volume information, refer to the standards Document Summary page on the ASTM website. 3 The last approved ve
13、rsion of this historical standard is referenced on www.astm.org. This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because it may not be technically possible to adequately depict all
14、changes accurately,ASTM recommends that users consult prior editions as appropriate. In all cases only the current version of the standard as published by ASTM is to be considered the official document. Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959
15、. United States 13.1.7 For the denitions of the other terms relating to geotextiles, refer to Terminology D4439. 3.1 Denitions:Forthedenitionsoftheothertermsrelatingtotextiles,generalgeosyntheticstermsusedinthisstandard,refer to Terminology D123D4439. 3.2 Denitions: 3.2.1 apparentopeningsize(AOS),O
16、95 ,nforageotextile,apropertythatindicatestheapproximatelargestparticlethatwould effectively pass through the geotextile. 4. Summary of Test Method 4.1 Ageotextile specimen is placed in a sieve frame, and sized glass beads are placed on the geotextile surface.The geotextile and frame are shaken late
17、rally so that the jarring motion will induce the beads to pass through the test specimen. The procedure is repeated on the same specimen with various size glass beads until its apparent opening size has been determined. 5. Signicance and Use 5.1 Using a geotextile as a medium to retain soil particle
18、s necessitates compatibility between it and the adjacent soil. This test method is used to indicate the apparent opening size in a geotextile, which reects the approximate largest opening dimension available for soil to pass through. 5.2 Test Method D4751 for the determination of opening size of geo
19、textiles is acceptable for testing of commercial shipments of geotextiles. Current estimates of precision, between laboratories, are being established. 5.2.1 IncaseofadisputearisingfromdifferencesinreportedtestresultswhenusingTestMethodD4751foracceptancetesting ofcommercialshipments,thepurchaserandt
20、hesuppliershouldconductcomparativeteststodetermineifthereisastatisticalbias between their laboratories. Competent statistical assistance is recommended for the investigation of bias.As a minimum, the two parties should take a group of test specimens that are homogeneous as possible and that are from
21、 a lot of material of the type in question.Thetestspecimensshouldthenberandomlyassignedinequalnumberstoeachlaboratoryfortesting.Theaverageresults from the two laboratories should be compared using Students t-test for unpaired data and an acceptable probability level chosen by the two parties before
22、the testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results in the light of the known bias. 6. Apparatus 6.1 Mechanical Sieve ShakerA mechanical sieve shaker, which imparts lateral and vertical m
23、otion to the sieve, causing the particles thereon to bounce and turn so as to present different orientations to the sieving surface, should be used.The sieve shaker should be a constant frequency device utilizing a tapping arm to impart the proper motion to the glass beads. 4 NOTE 1Care should be gi
24、ven to the cork or rubber contact point on shakers when the vertical motion comes from an arm striking the cork or rubber. Excessive wear on the cork or rubber could affect the motion imparted to the glass beads and, therefore, the test result. 6.2 Pan, Cover, and 200-mm (8-in.) Diameter Sieves. 4 A
25、 sieve shaker of this type is available from W. S. Tyler, Inc., 8200 Tyler Blvd., Mentor, OH 44060. TABLE 1 Glass Bead Sizes Bead Size Range Passing Retained Bead Size Designation A mm Sieve Number B mm Sieve Number B mm Sieve Number 2.0 10 1.70 12 1.7 12 1.4 14 1.18 16 1.18 16 1.00 18 0.850 20 0.85
26、0 20 0.710 25 0.600 30 0.600 30 0.500 35 0.425 40 0.425 40 0.355 45 0.300 50 0.300 50 0.250 60 0.212 70 0.212 70 0.180 80 0.150 100 0.150 100 0.125 120 0.106 140 0.106 140 0.090 170 0.075 200 0.075 200 A The designated bead size is the retained on size of the sieve pair used to size thebeads.Forexam
27、ple,beadsdesignatedNo.40arebeadsthatpasstheNo.35 sieve and are retained on the No. 40 sieve. These beads are typically sold as 35-40 beads. B See Specication E11. D475112 26.3 Spherical Glass Beads, 5 in size fractions in accordance with Table 1. It is only necessary to have on hand the bead size fr
28、actions necessary for the range of geotextiles for which testing is anticipated. The sizing of all beads shall be veried prior to eachusebysievingonthepairsofsievesshowninTable1.Prepareatleast50gofeachsizefractiontobeusedpriortobeginning the test. Bead sizes to be used in this test method are shown
29、in Table 1. 6.4 Balance, having a capacity adequate for the mass of samples anticipated and accurate to60.05 g. 6.5 Static Elimination,topreventtheaccumulationofstaticelectricitywhenthebeadsareshakenonthesurfaceofgeotextile. 6 Commercially available devices or anti-static sprays are acceptable. 6.6
30、Pan, for collecting sieved beads. 6.7 Flexible Rubber Template, Either a square shaped exible rubber template with a 203mm(8 in) diameter hole cut in it , or a 203 mm (8 in) diameter template, constructed from a durable, yet exible material such as rubber or neoprene. This template is used to trace
31、the 203 mm (8 in) diameter circles on the geotextile fabric for mounting into the sieves described in 6.2. (See Fig. 1) 5 Glass beads available from Cataphote Division, Ferro Corporation, P.O. Box 2369, Jackson, MS 39205, or Potters Industries, Inc., 377-T, Route 17, Hasbrouck Heights, NJ 07604, or
32、beads of equal quality have been found satisfactory for this purpose. 6 StaticEliminatorsavailablefromStaticmasterIonizingUnits,Model#2U500,NuclearProductsCo.,P.O.Box5178,ElMonte,CA91733,orWesternStaticEliminators Co., 215-219 S. WesternAvenue, Chicago, IL60612, have been found satisfactory for this
33、 purpose. For other availability addresses, see Footnote 7 of Test Method D4238. FIG. 1 Sample Worksheet D475112 37. Sampling 7.1 Lot SampleFor routine quality control testing, divide the product into lots and take the lot sample as directed in Practice D4354,Section7ProcedureBSamplingforQualityAssu
34、ranceTesting.ForSpecicationConformancetesting,sampleasdirected in Practice Sampling of Planar GeotextilesD4354, Section 6 Procedure ASampling for Specication Conformance. 7.1.1 Lot SampleForroutinequalitycontroltesting,dividetheproductintolotsandtakethelotsampleasdirectedinPractice D4354,Section7Pro
35、cedureBSamplingforQualityAssuranceTesting.ForSpecicationConformancetesting,sampleasdirected in Practice D4354, Section 6 Procedure ASampling for Specication Conformance. 7.1.2 LaboratorySampleAsalaboratorysampleforacceptancetesting,takeafullwidthswatch1-m(1-yd)longfromtheend of each roll of fabric i
36、n the lot sample, after rst discarding a minimum of 1 m (1 yd) of fabric from the very outside of the roll. 7.1.3 Test SpecimensCut ve specimens from each swatch in the laboratory sample with each specimen being cut to t the appropriate sieve pan. Cut the specimens from a single swatch spaced along
37、a diagonal line on the swatch. 7.2 Laboratory SampleAs a laboratory sample for acceptance testing, take a full width swatch 1-m (1-yd) long from the end of each roll of fabric in the lot sample, after rst discarding a minimum of 1 m (1 yd) of fabric from the very outside of the roll.Sampling of Circ
38、ular-Knitted Sock Geotextiles 7.2.1 Lot Sample for manufacturers quality control (MQC) testing - Divide rolls of sock covered perforated pipe Circular- Knitted Sock Geotextile Fabric into lots and take the lot sample as directed in Practice D4354, Section 7, Procedure B Sampling for Quality Assuranc
39、e Testing. 7.2.2 Laboratory SampleTo obtain a laboratory sample for MQC testing of the Circular-Knitted Sock Geotextile, follow the procedure below. 7.2.2.1 Apply the knitted sock Geotextile sample over the outside of the corresponding diameter of a 406 mm (16 in) length of perforated tubing or reas
40、onable facsimile. 7.2.2.2 Tie a kot in each end of the fabric so as to fully encase the pipe in the fabric. 7.2.2.3 Usingtheknotfromoneendofthefabric,suspendthegeotextilesencasedpipevertically.Gentlysuspenda1.13kg(2.5 lb) weight from the bottom to ensure intimate contact with the perforated pipe. Se
41、e Fig. 2. NOTE 2Pipes with diameters larger than 75 mm 150 mm( 3 in 6 in) may require heavier weights to ensure intimate contact between the pipe and sock material. Allow the suspended pipe with weight to hang for 2 minutes. 7.2.2.4 Using a exible 203 mm (8 in) diameter round template as a guide, tr
42、ace a circle on the surface of the fabric using an indelible marker. See Fig. 2. 7.2.2.5 Remove the fabric from the pipe section by untying or cutting off the knots at one or both ends in the fabric. Cut the fabric tube in a lengthwise direction at a position opposing the drawn circle, taking care t
43、o not cut the fabric within the circle. If so desired, the length of the specimen may be shortened by cutting the fabric in a cross wise direction, taking care not to cut the fabric closer than 75 mm (3 in) from the outside of the circle. The result will be a planar specimen of more or less rectangu
44、lar shape with a circle drawn approximately in its center. 7.3 Test SpecimensLot Sample for Specication Conformance TestingCutvespecimensfromeachswatchintheSampleas directedinPracticeD4354laboratorysamplewitheachspecimenbeingcuttottheappropriatesievepan.Cutthespecimensfrom a single swatch spaced alo
45、ng a diagonal line on the swatch.Section 8, Procedure C Sampling for Specication Conformance. 7.3.1 Laboratory SampleTo obtain a laboratory sample of the Circular Knitted Geotextile Fabric for acceptance testing of each lot of pipe, follow the procedure below. 7.3.1.1 Select a 3m (10 ft) section on
46、each lot of the sock covered pipe to be tested. 7.3.2 Using a length of string, twine or cord, secure the fabric to the pipe at each end of the 3m (10 ft) pipe section that was chosen in 7.3.3.1 in order to prevent the sock fabric from contracting lengthwise when the sock covered pipe sample is remo
47、ved from the roll or pipe section. Remove the 3m (10 ft) sock covered pipe section from the roll or pipe section by cutting the pipe at each end of the 3 m (10 ft) sample, outside of the ties. 7.3.3 Test SpecimensWith the fabric still secured to the pipe sample, use the exible rubber template, to dr
48、aw ve 2003 m (8 in) diameter circles at various locations around the circumference of each laboratory sample, equally spaced along its length and not closer than 100 mm (4 in) from either end of the pipe sample. 7.3.3.1 Remove the ties from the laboratory sample and remove the fabric from the pipe.
49、7.3.3.2 When securing specimens by wedging between two sieve frames cut the laboratory sample in a cross wise direction to create 5 specimens taking care not to make these cuts closer tan 75mm (3 in) from the outside of the circle. Continue to prepare thespecimensbycuttingthefabricinalengthwisedirectionatapositionopposingthecircle.Caremustbetakennottocutthrough the circle. The result will be the creation of 5 planar fabric specimens of more or less a rectangular shape with a circle drawn at its center. D475112 4D475112
