1、Designation: D 5970 09Standard Test Method forDeterioration of Geotextiles from Outdoor Exposure1This standard is issued under the fixed designation D 5970; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers evaluating the deterioration intensile strength and strain after outdoor exposure.1.2 The deterioration is a
3、ssessed as a reduction in strengthand strain at failure from the unexposed geotextile.1.3 The specific location of the light and weather exposureis made on the basis of a site specific decision between theparties involved.1.4 The values stated in SI units are to be regarded as thestandard. The inch-
4、pound units given in parentheses are forinformation only.1.5 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-priate safety and health practices and determine the applica-bili
5、ty of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 4439 Terminology for GeosyntheticsD 5035 Test Method for Breaking Force and Elongation ofTextile Fabrics (Strip Method)3. Terminology3.1 For definitions of terms related to geosynthetics, refer toTerminology D 443
6、9.3.2 Definitions:3.2.1 ultraviolet degradationthe photochemical changeinduced by exposure to ultraviolet radiation that results indeterioration of the performance characteristics of the poly-meric structure.4. Summary of Test Method4.1 Geotextile coupons are attached to a test frame oriented45 from
7、 the horizontal and facing the equator at designatedlocation for exposure times of 1, 2, 4, 8, 12, and 18 months.Exposure shall begin so as to ensure that material is exposedduring the maximum intensity of ultraviolet light of the year.4.1.1 Unexposed control coupons shall be retained fortesting.4.2
8、 After each exposure time the appropriate coupons arebrought into a laboratory for strength determination. Theresults of these tests are compared to the strength determinedfor the unexposed coupons. The user may be interested inexposure times other than specified in this test method. Thesetimes shou
9、ld be noted in reporting the results.4.3 The results are presented in the form of various plots.5. Significance and Use5.1 Outdoor exposure tests at one location may not beapplicable to a project site at another location. This test methodevaluates geotextiles under site specific atmospheric conditio
10、nsover an 18 month period. A degradation curve as per Section10.8, based on strength, elongation, or modulus, or all of these,may be developed for the geotextile being evaluated.5.2 This test method can be used for comparative testing ofthe degradation of geotextiles.5.3 This test method is consider
11、ed to be a performance testand as such the responsibility for its performance rests with thespecifying or purchasing agency.NOTE 1The intent of this procedure is to provide the user of this testmethod and geotextiles a standard by which to evaluate ultravioletdegradation in terms of site specific co
12、nditions, not in terms of incidentradiation and temperature. If desired, the user may want to have thenecessary measurement and recording equipment at each site to do this.However, the expense of doing so at each site may be prohibitive.Therefore, this is not a specific requirement of this test meth
13、od.6. Apparatus6.1 The frame for holding the coupons during the exposurephase of this test consists of a wooden frame (for example, asheet of exterior plywood) suitably braced so that it resides ata 45 angle with the horizontal.1This test method is under the jurisdiction of ASTM Committee D35 onGeos
14、ynthetics and is the direct responsibility of Subcommittee D35.02 on Endur-ance Properties.Current edition approved June 1, 2009. Published June 2009. Originallyapproved in 1996. Last previous edition approved in 2002 as D 597096(2002).2For referenced ASTM standards, visit the ASTM website, www.astm
15、.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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.1 The
16、frame is to be unpainted with the surface pro-tected from the effects of water and sunlight by varnishing thesurface.6.1.2 The supported frame is firmly positioned in a locationfree from obstruction from trees or other sources of shade. Itshall face the equator. It shall be placed such that no heat
17、or sunlight is reflected on it from surrounding buildings. If this is notpossible, it shall be noted in the test results report.6.1.3 The frame shall be suitably anchored using anchors,stakes, or adequate weights on the support legs.6.2 The geotextiles coupons shall be fastened with care insuch a wa
18、y that undue stresses that could result in prematurefailure of the geotextile are not induced. Staples may be used.7. Sampling7.1 Lot SampleDivide the product into lots and take oneunit per lot as the lot sample.7.1.1 DiscussionThis test method is intended to be per-formed by the purchaser for the p
19、urpose of determine geotex-tile performance under site specific conditions. Should amanufacturer perform this test it is not intended that eachmanufactured lot be sampled and tested. This is because thetest is considered to be time intensive.7.2 Laboratory SampleTake for the laboratory sample asampl
20、e of the geotextile extending the full width of the roll ofsufficient length along the selvedge from each sample roll suchthat the requirements of 8.1 are met. The sample shall excludematerial from the outer wrap of the roll or the inner wraparound the core unless the sample is taken at the producti
21、on siteat which point outer or inner wrap may be used.8. Test Coupon Preparation8.1 Cut six test coupons for each exposure time in themachine direction 300 by 180 mm (12 by 7 in.) from thelaboratory sample. The shortest measurement shall be in themachine direction:Machine or Cross Machine DirectionC
22、ontrol 1C1 1C2 1C3 1C4 1C5 1C6Month 1 1M(CM)1 1M2 1M3 1M4 1M5 1M6Month 2 2M1 2M2 2M3 2M4 2M5 2M6Month 18 18M1 18M2 18M3 8M4 18M5 18M68.1.1 Repeat 8.1 for the cross machine direction, with theshortest measurement in the cross machine direction.8.2 Cut six test coupons from each direction to be used a
23、scontrol coupons. These will act as the control specimens for allexposure times. Place the control coupons in a black polyeth-ylene bag, and seal to prevent deterioration of the controlcoupons due to exposure to ultraviolet light. Store the bag withthe coupons in a cool, dry location.9. Procedure9.1
24、 Firmly attach the six coupons for each exposure time tothe outdoor test frame as described in 6.2. In the case of staplesbeing used, locate them in the outer 25 mm (1 in.) of thecoupon, with approximately four staples per each 300 mm (12in.) width, and three staples along each 180 mm (7 in.) length
25、.NOTE 2If a full sheet of plywood, 1200 by 2400 mm (4 by 8 ft), isused, seven sets of coupons can be attached to the frame. This will allowan approximately 25 mm (1 in.) space around each sample.NOTE 3The long dimension of the frame and the coupons attached tothe frame shall run parallel to the surf
26、ace on which the frame rests.9.2 Obtain appropriate weather information, such as aver-age and mean temperatures, amount of rainfall, cloud coverversus sunlight, from the nearest national weather station.9.3 After each appropriate length of exposure, that is, 1, 2,4, 8, 12, and 18 months, remove the
27、appropriate coupons fromthe frame and bring them to the laboratory.9.3.1 Condition the coupons in the standard atmosphere fortesting geosynthetics.9.4 Trim the outer 25 mm (1 in.) of the long dimension fromeach side of the coupon such that the remaining materialmeasures 250 mm (10 in.) in width. Dis
28、pose of the trimmaterial.9.5 Carefully cut the remaining 250 mm (10 in.) widecoupon into five 50 mm (2 in.) wide, strip tensile testspecimens. The specimens will measure 180 mm (7 in.) long.9.6 Prepare the test specimens from the control coupons inthe same manner.9.7 Determine the breaking strength
29、in kilonewtons permetre (pounds force per inch) of the exposed and controlcoupons, as directed in Test Method D 5035 using a 50 mm(2-in.) width strip, except, a CRE or CRT type testing deviceshall be operated at 305 6 10 mm/min (12 612 in./min) unlessspecified otherwise. The distance between the cla
30、mps shall be75 6 1mm(36 0.05 in.). There may be no overall correlationbetween the results obtained with the CRE machine and theCRT machine. Consequently, these two breaking load testerscannot be used interchangeably.9.8 Record elongation at break.10. Calculation10.1 Determine the average ultimate fo
31、rce and elongationfor each exposure time (0, 1,2,4,8,12,18 months).10.2 Calculate the average strength for each exposure timeas follows:Tavg5 Pavg/w (1)where:Tavg= average strength in units of force per unit widthkN/m (lbf/in.),Pavg= average force from 10.1, andw = original width of test specimen, 5
32、0 mm (2 in.).10.3 Calculate a percent strength retained as follows:Tret5 Tavg/Tunexposed! 3 100 (2)where:Tret= percent strength retained,Tavg= strength of exposed specimens from 10.2,andTunexposed= strength of unexposed specimens from 10.2.10.4 Calculate the average elongation at break.10.5 Calculat
33、e the average strain at failure as follows:Savg5 Lavg2 Lorig!/Lorig(3)where:Savg= average strain at failure,Lavg= average elongation at failure from 10.4,D5970092Lorig= original gage length, that is, 75 mm (3 in.).10.6 Calculate a percent strain retained at failure by com-parison of the average stra
34、in at failure for exposed specimensto the average strain at failure for the unexposed specimens asfollows:Sret5 Savg/Sunex! 3 100 (4)where:Sret= percent strain at failure retained,Savg= average strain at failure from 10.4, andSunex= average strain at failure for unexposed (control)specimens.10.7 Fro
35、m the results of 10.2, determine the standarddeviation and the coefficient of variation for each exposuretime, and each direction tested.10.8 Plot graphs of percent strength retained, percent strainat failure, or modulus versus exposure time, or all of these.10.8.1 Plot graphs of percent strength re
36、tained, percentstrain at failure, or modulus versus total ultraviolet radiation, ifmeasured, or all of these, for each exposure time.11. Report11.1 Report the following information:11.1.1 The test was performed according to this test method,11.1.2 Any variations from this test method,11.1.3 A listin
37、g of the test results from Section 10,11.1.3.1 If requested the following results may be reported:individual specimen results, standard deviations and coefficientof variations for each exposure time and,11.1.4 The plots developed in 10.8,11.1.5 A summary of mean and average temperatures,rainfall, an
38、d cloud cover versus sunlight, if obtained fromweather stations, for each exposure period,11.1.6 The inclusive dates of exposure for each set of testresults, and11.1.7 The orientation of the exposure based on the azimuthof the exposed face.12. Precision and Bias12.1 PrecisionThe precision of this te
39、st method is beingdetermined.12.2 BiasThe bias of this test method, if any, is beingdetermined.13. Keywords13.1 degradation; geotextile; outdoor exposure; strengthretained; ultraviolet degradationASTM International takes no position respecting the validity of any patent rights asserted in connection
40、 with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible t
41、echnical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful conside
42、ration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr
43、 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 aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D5970093
