ASTM_D_4751-16.pdf

Designation:D4751-16INTERNATIONALStandard Test Methods forDetermining Apparent Opening Size of a GeotextileThis 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 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.ScopeD6767 Test Method for Pore Size Characteristics of Geotex-1.1 These test methods cover the determination of thetiles by Capillary Flow Testapparent opening size(AOS)of a geotextile either by dry-E11 Specification for Woven Wire Test Sieve Cloth and Testsieving glass beads through a geotextile(Method A)or bySievesusing a capillary porometer(Method B).E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method1.2 Method B will not be used in lieu of Method A unlessthe prequalification procedure specified in this standard is3.Terminologyfollowed.3.1 Definitions:For general geosynthetics terms used in this1.3 These test methods show the values in both SI units andstandard,refer to Terminology D4439.inch-pound units.SI units is the technically correct name for3.2 Definitions:the system of metric units known as the International System of3.2.1 apparent opening size(AOS),O9s,n-for a geotextile,Units.Inch-pound units is the technically correct name for thea property that indicates the approximate largest particle thatcustomary units used in the United States.The values inwould effectively pass through the geotextile.inch-pound units are provided for information only.3.2.1.1 Discussion-While the same O95 symbol is used1.4 This standard does not purport to address all of theboth in these test methods for defining the AOS of a geotextilesafety concerns,if any,associated with its use.It is theas well as in Test Method D6767 for determining the pore sizeresponsibility of the user of this standard to establish appro-of geotextiles by capillary flow,they are not necessarilypriate safety and health practices and determine the applica-equivalent.The O95 values are defined in terms of theirbility of regulatory limitations prior to use.respective test methods.Therefore the AOS version of the O952.Referenced Documentsvalue that is determined with Method B may not be identical tothe 095 value determined per Test Method D6767.2.1 ASTM Standards:2C136/C136M Test Method for Sieve Analysis of Fine and4.Summary of Test MethodsCoarse Aggregates4.1 Glass Bead Dry-Sieving Method A-A geotextile speci-D1331 Test Methods for Surface and Interfacial Tension ofmen is placed in a sieve frame,and sized glass beads are placedSolutions of Paints,Solvents,Solutions of Surface-Activeon the geotextile surface.The geotextile and frame are shakenAgents,and Related Materialslaterally so that the jarring motion will induce the beads to passD1776/D1776M Practice for Conditioning and Testing Tex-through the test specimen.The procedure is repeated on thetilessame specimen with various size glass beads until its apparentD4354 Practice for Sampling of Geosynthetics and Rolledopening size has been determined.This method is consideredErosion Control Products(RECPs)for Testingthe referee method in the case of inter-laboratory disputesD4439 Terminology for Geosyntheticsinvolving Method B.4.2 Capillary Porometer Method B-A geotextile specimen These test methods are under the jurisdiction of ASTM Committee D35 onis subject first to an air flow test,where the air flow rate andGeosynthetics and is the direct responsibility of Subcommittee D35.03 on Perme-pressure are measured.Then the same specimen is wetted withability and Filtration.Current edition approved July 1,2016.Published August 2016.Originallymineral oil and subject to an increasing air pressure whileapproved in 1993.Last previous version approved in 2012 as D4751-12.DOI:measuring the resulting flow rate.The opening sizes are10.1520/D4751-16.calculated from this data using standard capillary theory and2 For referenced ASTM standards,visit the ASTM website,www.astm.org,orthe specific algorithm defined in these test methods.contact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page on4.2.1 The apparent opening size of a geotextile is defined inthe ASTM website.terms of the dry-sieving test method.This method includes aCopyright C ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States|D4751-16procedure for correlating the porometer test data to the Methodsample as directed in Practice D4354,Section 6,ProcedureA results so that Method B is qualified to generate valuesA-Sampling for Specification Conformance.equivalent to the glass bead dry-sieving Method A.6.1.2 Laboratory Sample-As a laboratory sample for ac-5.Significance and Useceptance testing,take a full width swatch 1-m(1-yd)long fromthe end of each roll of fabric in the lot sample,after first5.1 Using a geotextile as a medium to retain soil particlesdiscarding a minimum of 1 m(1 yd)of fabric from the verynecessitates compatibility between it and the adjacent soil.Thisoutside of the roll.test method is used to indicate the apparent opening size in a6.1.3 Test Specimens-Cut five specimens from each swatchgeotextile,which reflects the approximate largest openingin the laboratory sample with each specimen being cut to fit thedimension available for soil to pass through.appropriate specimen holder for Method A or the porometer5.2 Test Methods D4751 for the determination of openingsample holder for Method B.Cut the specimens from a singlesize of geotextiles is acceptable for testing of commercialswatch spaced along a diagonal line on the swatch.shipments of geotextiles.Current estimates of precision,be-6.2 Sampling of Circular-Knitted Sock Geotextiles:tween laboratories,have been established.6.2.1 For a lot sample for manufacturers quality control5.3 Apparent Opening Test results obtained using Method A(MQC)testing,divide rolls of Circular,Knitted Sock Geotex-may differ from test results obtained with Method B.It is thetile Fabric into lots and take the lot sample as directed inintent of this test method to confirm the equivalency of thePractice D4354,Section 7,Procedure B-Sampling for QualityMethod B results before permitting the use of this alternative.Assurance Testing.For a Lot Sample for Specification Confor-Laboratories electing the use of Method B must first determinemance Testing,sample as directed in Practice D4354,Sectionany bias that exists between the two methods and document a8,Procedure C-Sampling for Specification Conformance.reliable correlation in accordance with this test method.6.2.2 Laboratory Sample-To obtain a laboratory sample5.3.1 The correlation between the Method B results and thefor MQC testing of the Circular-Knitted Sock Geotextile,Method A results must be established and meet the require-follow the procedure below:ments of this test method for every different geotextile product6.2.2.1 Apply the knitted sock Geotextile sample over thetype tested with Method B.Geotextiles from different manu-outside of the corresponding diameter of a 406 mm(16 in.)facturers or with different nominal unit weights are consideredlength of perforated tubing or reasonable facsimile having thedifferent products.A minimum of three test results must besame diameter as the pipe material for which the sock iscompared with all three satisfying the established correlation.intended.6.2.2.2 Tie a knot in each end of the fabric so as to fullyNoTE 1-The correlation should be confirmed for a particular productencase the pipe in the fabric.by comparing a minimum of three test results when there are changes inthe manufacturing of a specific pre-qualified geotextile.6.2.2.3 Using the knot from one end of the fabric,suspend5.4 In case of a dispute arising from differences in reportedthe geotextiles encased pipe vertically.Gently suspend a1.13 kg(2.5 lb)weight from the bottom to ensure intimatetest results when using Test Method D4751 for acceptancetesting of commercial shipments,the purchaser and the sup-contact with the perforated pipe.See Fig.la.Allow theplier should conduct comparative tests to determine if there issuspended pipe with weight to hang for 2 min.a statistical bias between their laboratories.Competent statis-NoTE 2-Pipes with diameters larger than 75 to 150 mm(3 to 6 in.)tical assistance is recommended for the investigation of bias.may require heavier weights to ensure intimate contact between the pipeAs a minimum,the two parties should take a group of testand sock material.specimens that are homogeneous as possible and that are from6.2.2.4 For Method A,using a flexible 203 mm(8 in.)a lot of material of the type in question.The test specimensdiameter round template as a guide,trace a circle on the surfaceshould then be randomly assigned in equal numbers to eachof the fabric using an indelible marker.See Fig.1c.Removelaboratory for testing.The average results from the twothe fabric from the pipe section by untying or cutting off thelaboratories should be compared using Students 1-test forknots at one or both ends in the fabric.Cut the fabric tube in aunpaired data and an acceptable probability level chosen by thelengthwise direction at a position opposing the drawn circle,two parties before the testing is begun.If a bias is found,eithertaking care to not cut the fabric within the circle.If so desired,its cause must be found and corrected or the purchaser and thethe length of the specimen may be shortened by cutting thesupplier must agree to interpret future test results in the light offabric in a cross wise direction,taking care not to cut the fabricthe known bias.closer than 75 mm(3 in.)from the outside of the circle.The5.4.1 In the event that the dispute involves test resultsresult will be a planar specimen of more or less rectangularproduced with the capillary porometer,Method A is consideredshape with a circle drawn approximately in its center.the referee method for Test Methods D4751.6.2.2.5 For Method B test specimens,affix an adhesive-backed foil to the fabric which has a 25-mm diameter hole die6.Samplingcut from the center,and a sufficient outside diameter to exceed6.1 Sampling of Planar Geotextiles:the outside diameter of the porometer sample holder.This foil6.1.1 Lot Sample-For routine quality control testing,dividemust be rigid enough to preserve the geometry of the materialthe product into lots and take the lot sample as directed inproduced by this technique.The five foil-taped porometerPractice D4354,Section 7,Procedure B-Sampling for Qualityspecimens are then cut with the porometer specimen die,Assurance Testing.For Specification Conformance testing,positioning the 25-mm opening in the center.244D4751-16Fig laSquare Template with Hole Cut in It Fig 1bFig lcRound TemplateFigldF1G.13D4751-166.3 Lot Sample for Specification Conformance Testing-NoTE 3-It is recognized that in practice,geosynthetic materials areSample as directed in Practice D4354,Section 8,Procedurefrequently not weighed to determine when moisture equilibrium has beenC-Sampling for Purchasers Specification Conformance Test-reached.While such a method cannot be accepted in cases of dispute,itmay be sufficient in routine testing to expose the material to the standarding.atmosphere for testing geosynthetics for a reasonable period of time6.3.1 Laboratory Sample-To obtain a laboratory sample ofbefore the specimens are tested.A time of at least 24 h has been foundthe Circular Knitted Geotextile Fabric for acceptance testing ofacceptable in most cases.However,certain fibers may contain moreeach lot of pipe,follow this procedure:moisture upon receipt than after conditioning.When this is known,apreconditioning cycle,as described in Practice D1776/D1776M,may be6.3.1.1 Select a 3 m(10 ft)section on each lot of the sockagreed upon by the contractual parties.covered pipe to be tested.6.3.2 Using a length of string,twine or cord,secure the8.Apparatusfabric to the pipe at each end of the 3 m(10 ft)pipe section that8.1 Mechanical Sieve Shaker-A mechanical sieve shaker,was chosen in 6.3.1.1 in order to prevent the sock fabric fromwhich imparts lateral and vertical motion to the sieve,causingcontracting lengthwise when the sock covered pipe sample isthe particles thereon to bounce and turn so as to presentremoved from the roll or pipe section.Remove the 3 m(10 ft)different orientations to the sieving surface,should be used.sock covered pipe section from the roll or pipe section byThe sieve shaker should be a constant frequency devicecutting the pipe at each end of the 3 m(10 ft)sample,outsideutilizing a tapping arm to impart the proper motion to the glassof the ties.beads.6.3.3 Test Specimens-With the fabric still secured to thepipe sample,using a flexible 203 mm(8 in.)diameter roundNoTE 4-Care should be given to the cork or rubber contact point ontemplate for Method A,draw five 203-mm(8-in.)diametershakers when the vertical motion comes from an arm striking the cork orrubber.Excessive wear on the cork or rubber could affect the motioncircles at various locations around the circumference of eachimparted to the glass beads and,therefore,the test result.laboratory sample,equally spaced along its length,and not8.2 Pan,Cover,and 200-mm(8-in.)Diameter Sieves.closer than 100 mm(4 in.)from either end of the pipe sample.For Method B,affix adhesive-backed foil to the fabric which8.3 Spherical Glass Beads in size fractions in accordancehas a 25-mm diameter hole die cut from the center,and awith Table 1.It is only necessary to have on hand the bead sizesufficient outside diameter to exceed the outside diameter offractions necessary for the range of geotextiles for whichthe porometer sample holder.This foil must be rigid enough totesting is anticipated.The sizing of all beads shall be verifiedpreserve the geometry of the material produced by thisprior to each use by sieving on the pairs of sieves shown intechnique.The five foil-taped porometer specimens are thenTable 1.Prepare at least 50 g of each size fraction to be usedcut with the porometer specimen die,positioning the 25-mmprior to beginning the test.Bead sizes to be used in this testopening in the center.method are shown in Table 1.6.3.3.1 Remove the ties from the laboratory sample and8.4 Balance,having a capacity adequate for the mass ofremove the fabric from the pipe.samples anticipated and accurate to 0.05 g.6.3.3.2 When securing specimens by wedging between twosieve frames cut the laboratory sample in a cross wise directionto create 5 specimens taking care not to make these cuts closertan 75 mm(3 in.)from the outside of the circle.Continue to3 The sole source of supply of the apparatus known to the committee at this timeprepare the specimens by cutting the fabric in a lengthwiseis W.S.Tyler,Inc.,8200 Tyler Blvd.,Mentor,OH 44060.If you are aware ofalternative suppliers,please provide this information to ASTM Internationaldirection at a position opposing the circle.Care must be takenHeadquarters.Your comments will receive careful consideration at a meeting of thenot to cut through the circle.The result will be the creation ofresponsible technical committee,which you may attend.5 planar fabric specimens of more or less a rectangular shapewith a circle drawn at its center.TABLE 1 Glass Bead SizesBead Size RangeMETHOD A-DRY-SIEVING WITH GLASS BEADSPassingRetainedBead Size DesignationASieveSieveSievemmNumberBmmNumberemmNumber7.Specimen Preparation2.0101.70121.7127.1 Weigh the Method A test specimens and then submerge1.4141.18161.18161.00180.850200.85020them in distilled water for 1 h at the standard atmosphere for0.710250.600300.60030testing.Bring the specimens to moisture equilibrium in the0.500350.425400.42540atmosphere for testing geosynthetics.Equilibrium is consid-0.355450.300500.300500.250600.212700.21270ered to have been reached when the change in the mass of the0.180800.1501000.150100specimen in successive weight measurements made at intervals0.1251200.1061400.106140of not less than 2 h does not exceed 0.1 g.0.0901700.0752000.075200 The designated bead size is the retained on size of the sieve pair used to size7.2 The drying process may be accelerated with the use of athe beads.For example,beads designated No.40 are beads that pass the No.35fan.The specimens shall not be dried in an oven or by exposingsieve and are retained on the No.40 sieve.These beads are typically sold as35-40 beads.them to elevated temperatures above the standard laboratoryB See Specification E11.atmosphere for geosynthetic testing.4D4751-168.5 Static Elimination,to prevent the accumulation of static9.7 Weigh the glass beads that pass through the specimen,electricity when the beads are shaken on the surface ofand record data.(See Fig.2 for a sample worksheet which cangeotextile.Commercially available devices or anti-static spraysbe used to record the desired data).are acceptable.9.8 Repeat 9.3 through 9.7 using the next larger bead size8.6 Pan,for collecting sieved beads.fraction.Repeat the trial using successively larger bead size8.7 Flexible Rubber Template,either a square shaped flex-fractions until the weight of beads passing through the speci-ible rubber template with a 203-mm(8-in.)diameter hole cut inmen is 5%or less.Perform the trials such that the percentit,or a 203-mm(8-in.)diameter template,constructed from apassing decreases from a value greater than 5 to a value lessdurable,yet flexible material such as rubber or neoprene.Thisthan or equal to 5%template is used to trace the 203-mm(8-in.)diameter circles on9.9 Repeat 9.2-9.8 for all five specimens.the geotextile fabric for mounting into the sieves described in10.Calculation8.2.(See Fig.1.)10.1 For each size of beads tested with each specimen,9.Procedurecompute to the nearest percent by weight of the beads passingthrough the specimen using Eq 1:9.1 Run the test at the atmosphere for testing geotextiles inB=100P/T(1)such a manner that static electricity is prevented from affectingtest results.If standard atmosphere cannot be maintained andwhere:static electricity is noticed,two methods are available that willB beads passing through specimen,%prevent static electricity:P mass of glass beads in the pan,g,and9.1.1 Install static eliminating devices equally spaced aboutT total mass of glass beads used,g.the circumference of sieve and one on center of cover,or10.2 Record calculations and percent beads passing(see9.1.2 Apply commercially available anti-static spray uni-Fig.2).formly to the geotextile.10.3 Assign the AOS for each specimen as the size desig-9.2 Secure the geotextile in such a way that it is taut,nation in millimetres(see 8.3)of the beads of which 5 or lesswithout wrinkles or bulges.The geotextile must not bepass.These AOS values are in millimetres,and are taken fromstretched or deformed such that it changes or distorts thethe Bead Size Designationcolumn of Table 1.openings in the fabric.Two systems may be used to secure thegeotextiles sample:10.4 Determine the AOS in millimetres by averaging thefive AOS values obtained in 10.3.9.2.1 Wedge between two sieve frames.9.2.2 Secure with the perimeter seal device inside the sieve10.5 Determine the sample AOS,expressed in terms ofsieve number,as the number of the U.S.Sieve(see the sieveframe.number column under Bead Size Designation of Table 1)NorE 5-For knitted sock geotextiles,some manipulation of thehaving nominal opening,in millimetres,equal to or next largerspecimens may be necessary to ensure that the marked out circle is fittedthan the AOS,in millimetres,obtained in 10.4.to the sieve frame properly.9.3 Prior to use,sieve the glass beads in the laboratory to11.Plottingverify size of beads11.1 It is often desirable due to variability among the fivetest specimen results to determine the AOS value by plottingNorE 6-All size glass beads are sieved through a single specimen ofgeotextile unless the geotextile has an average thickness equal to orthe percentage of beads passing the specimen versus the beadgreater than 2.3 mm(0.091 in.).A geotextile of this thickness or greatersize for each of the bead sizes used for each specimen.When(especially nonwovens)may trap beads within the layers of the fabric,plotting is desirable,proceed as follows:which may pass through the specimen when testing with a different bead11.1.1 For each specimen,plot the values of Percent Passingsize,thus creating an error in the test results.In the case of the thicker(Ordinate)versus Bead Size,mm(Abscissa)on semi-loggeotextiles,a different specimen may be used for each bead size;however,graph.Draw a straight line connecting the two data pointsit should be noted in the report that different specimens were used.representing the bead sizes that are immediately on either side9.4 Start with the smallest diameter glass beads that will beof the 5%passing ordinate.The particle size in millimetrestested.Place 50 g of one size glass beads on the center of the(abscissa)at the intersection of the straight line plotted and thegeotextile.5%passing ordinate is the AOS of the specimen in9.5 Place cover and pan on sieve frame and place in shaker.millimetres,that is,the theoretical bead size that would resultShake sieves for 10 min.in exactly 5 passing the specimen.11.1.2 Determine the sample AOS,in millimetres,by aver-9.6 Place the glass beads still on the surface of the specimenaging the five AOS values obtained by the graphic interpolationin a pan and weigh.Include beads that fall off as a result ofin11.1.1.turning the specimen over and tapping the rims of the sieves.11.1.3 Optional:When requested,determine the sampleNorE 7-This step provides information concerning the amount ofAOS,expressed in terms of sieve number,as the number of theglass beads trapped within the geotextile and the amount of any beads lostU.S.Sieve(see the sieve number column under Bead Sizeduring testing.Designation of Table 1)having nominal opening,in