1、Designation: D6575/D6575M 16Standard Test Method forDetermining Stiffness of Geosynthetics Used as TurfReinforcement Mats (TRMs)1This standard is issued under the fixed designation D6575/D6575M; the number immediately following the designation indicates theyear of original adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the stiff-ness of geosynthetics used as Turf Rein
3、forcement Mats (TRM).1.2 The method is applicable to TRMs of any fiber contentand any number of components.1.3 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, eachsystem shall
4、be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 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-pr
5、iate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1388 Test Method for Stiffness of FabricsD1776/D1776M Practice for Conditioning and Testing Tex-tilesD4354 Practic
6、e for Sampling of Geosynthetics and RolledErosion Control Products(RECPs) for TestingD4439 Terminology for GeosyntheticsD6566 Test Method for Measuring Mass per Unit Area ofTurf Reinforcement MatsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an
7、 Interlaboratory Study toDetermine the Precision of a Test Method2.2 Federal Standards:3CCC-T-191b Textile Test Methods No. 5206.23. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 bending length, n:3.1.1.1 general, adja measure of the interaction betweengeosynthetic weight and g
8、eosynthetic stiffness as shown by theway in which a geosynthetic bends under its own weight. Itreflects the stiffness of a geosynthetic when bent in one planeunder the force of gravity, and is one component of drape.3.1.1.2 DiscussionBending length is called drape stiffnessin Federal Specification C
9、CC-T-191b.3.1.1.3 specific, adjthe cube root of the ratio of theflexural rigidity to the mass per unit area.3.1.2 flexural rigidity, n:3.1.2.1 general, adjresistance to bending.3.1.2.2 DiscussionResistance to bending or “flexural ri-gidity” is called flex stiffness in Federal Specification CCC-T-191
10、b.3.1.2.3 specific, adjthe couple on either end of a sample ofunit width bent into unit curvature in the absence of anytension.3.1.2.4 DiscussionThe methods measure the bendinglength. Flexural rigidity is calculated directly by multiplyingthe cube of the bending length by the weight per unit area (s
11、ee3.1.1.3).3.1.3 stiffness, nresistance to bending.3.2 DefinitionsFor definitions of other textile or geosyn-thetic terms used in this test method, refer to TerminologiesD123 and D4439.4. Significance and Use4.1 In general this test method is adapted from tests devel-oped for woven fabrics (previous
12、ly designated as Test MethodD1388).4.2 The cantilever test method may not be suitable fortesting products that are very limp or have a marked tendencyto curl or twist at a cut edge.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of S
13、ubcommittee D35.05 on Geosyn-thetic Erosion Control.Current edition approved July 1, 2016. Published July 2016. Originally approvedin 2000. Last previous edition approved in 2014 as D6575 14a. DOI: 10.1520/D6575_D6575M-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontac
14、t ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Publishing Office, 732 N. Capitol St., NW,Washington, DC 20401-0001, http:/www.gpo.gov.Copyright ASTM Inter
15、national, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Cantilever Method5. Summary of Method5.1 A specimen of the TRM is slid in a direction parallel toits long dimension, so that its end projects from the edge of ahorizontal surface. The length of overhang is
16、measured whenthe tip of the test specimen is depressed under its own weightto the point where the line joining the tip to the edge of theplatform makes an angle of 41.5 with the horizontal. One halfof this length is the bending length of the specimen. The cubeof this quantity multiplied by the weigh
17、t per unit area of thegeosynthetic is the flexural rigidity.5.2 This test method is known also as the Single CantileverTest.6. Apparatus6.1 Stiffness Tester, having the following parts:6.1.1 Horizontal Platform, with a minimum area of 18 by12 in. 457.2 by 304.8 mm and having a smooth low-friction,fl
18、at surface such as polished metal or plastic.Aleveling bubbleshall be incorporated in the platform, or be available forverification that the horizontal platform is level.6.1.2 Indicator, inclined at an angle of 41.5 below the planeof the platform surface.6.1.3 Weight, consisting of a metal bar not l
19、ess than 4 by18 in. 101.6 by 457.2 mm by about18 in. 3 mm thick.6.1.4 Scale and Pointer, to measure the length of theoverhang.7. Conditioning7.1 For tests made as directed in 9.1 9.5, bring thespecimens to a moisture equilibrium in the atmosphere fortesting TRMs, that is a temperature of 70 6 4F 21
20、6 2Cand relative humidity of 60 6 10 %. See Practice D1776/D1776M.8. Selection and Preparation of Specimens8.1 Cut test specimens 4 in. wide by a minimum of 18 in.long 101.6 by 457.2 mm; longer specimens may be needed toobtain a measurement. Cut four specimens with the longdirection parallel to the
21、machine direction and four with thelong direction parallel to the transverse (or cross-machine)direction. If the geosynthetic is not uniform or a higher degreeof precision is required, more may be tested. Vary cutting thespecimens in such a way that the machine direction specimensdo not contain the
22、same machine direction yarns/filaments forthe machine direction tests and cut the cross-machine directionspecimens so that separate cross-machine direction yarns/filaments are contained in each. Avoid selvages, end pieces,and creased or folded places, and handle the specimens as littleas possible. A
23、dditional conditioning may be needed to removecurl from rolled geosynthetics. See Practice D4354.NOTE 1Some TRMs are constructed from several component mate-rials and sample preparation must be performed in such a way as tomaintain the structural integrity of the product. Procedures found to besucce
24、ssful for cutting test specimens from TRMs include the use of hotknives to seal the edges and the use of bags and slip covers to keep allcomponents together during sample preparation. The method of cuttingthe specimen should be included in the report.9. Procedure9.1 Make tests on conditioned specime
25、ns in the standardatmosphere for testing.9.2 Set the tester on a table or bench so that the horizontalplatform and inclined reference lines are at eye level. Adjustthe platform so that it is horizontal as indicated by the levelingbubble.9.3 Place a specimen on the platform with the weight on topof i
26、t so that the leading edges coincide. Holding the weight ina horizontal plane, slide the specimen and weight slowly andsteadily until the leading edges project beyond the edge of theplatform. Take the measurement of the overhang where thecenter of the leading edge of the specimen touches the incline
27、.Do not measure specimens that twist more than 45. Read thelength of overhang from the scale to the nearest 1 mm.9.4 Take four readings from each specimen, with each sideup, first at one end and then the other.9.5 Determine the mass per unit area according to TestMethod D6566.10. Calculation10.1 Unl
28、ess otherwise specified, average the four readingsobtained from all the specimens cut parallel to the machinedirection. Do the same for those cut parallel to the cross-machine direction. In some cases it may be of interest todifferentiate between the sides of the geosynthetic by averagingthose readi
29、ngs made with the face side up separately fromthose with the reverse side up. If this is done, specify thedirection of bending. Call these averages the “length ofoverhang,” and express them in centimetres. Calculate thebending length, c, in centimetres, and the flexural rigidity, G,inmg/cm by Eq 1 a
30、nd 2:Bending length, c 5 Lo/2 (1)where:Lo= length of overhang, cm.Flexural rigidity, G 5 W 3 Lo/2!35 W 3 c3(2)where:W = weight per unit area, mg/cm2.NOTE 2To obtain the weight in mg/cm2, multiply oz/yd2by 3.39.Federal Specification CCC-T-191b gives flexural rigidity in in.-lb. Toconvert in.-lb to mg
31、-cm, multiply by 1.15 106.11. Report11.1 Report the following information:11.2 Report to three significant figures the flexural rigidityof the machine direction and cross-machine direction sepa-rately. If an overall average figure for the geosynthetic isrequired, calculate the geometric mean of thes
32、e two values byEq 3:Go5 GMDGCD!1/2(3)where:Go= overall flexural rigidity,D6575/D6575M 162GMD= machine direction flexural rigidity, andGCD= cross-machine flexural rigidity.12. Precision and Bias412.1 PrecisionThe precision of this test method is basedon an interlaboratory study of Test Method D6575,
33、conductedin 2013. Five laboratories participated in this study. Each of thelabs reported three replicate test results for three different typesof mats. Every test result reported represents an individualdetermination. Except for the use of only five laboratories,Practice E691 was followed for the de
34、sign and analysis of thedata; the details are given in ASTM Research Report No.RR:D35-1019.12.1.1 Repeatability (r)The difference between repetitiveresults obtained by the same operator in a given laboratoryapplying the same test method with the same apparatus underconstant operating conditions on i
35、dentical test material withinshort intervals of time would in the long run, in the normal andcorrect operation of the test method, exceed the followingvalues only in one case in 20.12.1.1.1 Repeatability can be interpreted as the maximumdifference between two results, obtained under repeatabilitycon
36、ditions, that is accepted as plausible due to random causesunder normal and correct operation of the test method.12.1.1.2 Repeatability limits are listed in Tables 1 and 2.12.1.2 Reproducibility (R)The difference between twosingle and independent results obtained by different operatorsapplying the s
37、ame test method in different laboratories usingdifferent apparatus on identical test material would, in the longrun, in the normal and correct operation of the test method,exceed the following values only in one case in 20.12.1.2.1 Reproducibility can be interpreted as the maximumdifference between
38、two results, obtained under reproducibilityconditions, that is accepted as plausible due to random causesunder normal and correct operation of the test method.12.1.2.2 Estimated reproducibility limits are listed in Tables1 and 2.12.1.3 The above terms (repeatability limit and reproduc-ibility limit)
39、 are used as specified in Practice E177.12.1.4 Any judgment in accordance with statements 12.1.1and 12.1.2 would normally have an approximate 95 % prob-ability of being correct, however the precision statistics ob-tained in this ILS must not be treated as exact mathematicalquantities which are appli
40、cable to all circumstances and uses.The limited number of materials tested and laboratories report-ing results guarantees that there will be times when differencesgreater than predicted by the ILS results will arise, sometimeswith considerably greater or smaller frequency than the 95 %probability li
41、mit would imply. The repeatability limit and thereproducibility limit should be considered as general guides,and the associated probability of 95 % as only a roughindicator of what can be expected.12.2 BiasAt the time of the study, there was no acceptedreference material suitable for determining the
42、 bias for this testmethod, therefore no statement on bias is being made.12.3 The precision statement was determined through sta-tistical examination of 90 results, from five laboratories, onthree materials.12.3.1 To judge the equivalency of two test results, it isrecommended to choose the mat materi
43、al closest in character-istics to the test material.4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D35-1019. ContactASTM CustomerService at serviceastm.org.TABLE 1 StiffnessMachine Direction (mg-cm)MaterialAverageARepeatability
44、StandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx SrSRrRDouble Net Blanket 17047 3833 9705 10732 27173Double Net TRM #1 47758 14032 27718 39290 77610Double Net TRM #2 30694 11958 15501 33483 43402AThe average of the laboratories calculated averages.D6575/D6575M
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48、mittee on Standards, at the address shown below.This standard is copyrighted 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 aboveaddr
49、ess 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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 2 StiffnessCross-Machine Direction (mg-cm)MaterialAverageARepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitx SrSRrRDouble Net Blanket 18808 2835 7513 7937 21036Double Net TRM #1
