1、Designation: D5970 09D5970/D5970M 16Standard Test Method forDeterioration of Geotextiles from Outdoor Exposure1This standard is issued under the fixed designation D5970;D5970/D5970M; the number immediately following the designation indicatesthe year of original adoption or, in the case of revision,
2、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 evaluating the deterioration in tensile strength and strain after outdoor exposure
3、.1.2 The deterioration is assessed as a reduction in strength and strain at failure from the unexposed geotextile.1.3 The specific location of the light and weather exposure is made on the basis of a site specific decision between the partiesinvolved.1.4 The values stated in either SI units or inch-
4、pound units are to be regarded separately as the standard. The inch-pound unitsgiven in parentheses are for information only.values stated in each system may not be exact equivalents; therefore, each systemshall be used independently of the other. Combining values from the two systems may result in
5、non-conformance with the standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitati
6、ons prior to use.2. Referenced Documents2.1 ASTM Standards:2D4439 Terminology for GeosyntheticsD5035 Test Method for Breaking Force and Elongation of Textile Fabrics (Strip Method)G7/G7M Practice for Atmospheric Environmental Exposure Testing of Nonmetallic MaterialsG113 Terminology Relating to Natu
7、ral and Artificial Weathering Tests of Nonmetallic Materials3. Terminology3.1 For definitions of terms related to geosynthetics, refer to Terminology D4439.3.2 For definitions of terms related to weathering, refer to Terminology G113.3.3 Definitions:3.3.1 ultraviolet degradationthe photochemical cha
8、nge induced by exposure to ultraviolet radiation that results indeterioration of the performance characteristics of the polymeric structure.3.3.2 weathering degradationthe change induced by exposure to outdoor conditions, that results in deterioration of theperformance characteristics of the polymer
9、ic structure.4. Summary of Test Method4.1 Geotextile coupons are attached to a test frame oriented 45 from the horizontal and facing the equator at designated locationfor exposure times of 1, 2, 4, 8, 12, and 18 months. Exposure shall begin so as to ensure that material is exposed during themaximum
10、intensity of ultraviolet light of the year. Unless otherwise specified, the test should be initiated in May in the northernhemisphere, and in November in the southern hemisphere.4.1.1 Unexposed control coupons coupons, or file specimens according to Terminology G113, shall be retained for testing.4.
11、2 After each exposure time the appropriate coupons are brought into a laboratory for strength determination. The results ofthese tests are compared to the strength determined for the unexposed coupons. The user may be interested in exposure times otherthan specified in this test method. These times
12、should be noted in reporting the results.1 This test method is under the jurisdiction of ASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35.02 on Endurance Properties.Current edition approved June 1, 2009Jan. 1, 2016. Published June 2009January 2016. Originally
13、approved in 1996. Last previous edition approved in 20022009 asD597096(2002).D597009. DOI: 10.1520/D5970-09.10.1520/D5970_D5970M-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume informa
14、tion, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depi
15、ct all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof 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, PA 194
16、28-2959. United States14.3 The results are presented in the form of various plots.4.4 Additional recommendations may be found in Practice G7/G7M and Terminology G113.5. Significance and Use5.1 Outdoor exposure tests at one location may not be applicable to a project site at another location. This te
17、st method evaluatesgeotextiles under site specific atmospheric conditions over an 18 month 18-month period.Adegradation curve as per Section 10.8,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 compa
18、rative testing of the degradation of geotextiles.5.3 This test method is considered to be a performance test and 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 test method and geotextiles
19、a standard by which to evaluate ultravioletweatheringdegradation in terms of site specific conditions, not in terms of incident radiation and temperature. If desired, the user may want to have the necessarymeasurement and recording equipment at each site to do this. However, the expense of doing so
20、at each site may be prohibitive. Therefore, this is nota specific requirement of this test method.6. Apparatus6.1 The frame for holding the coupons during the exposure phase of this test consists of a wooden frame (for example, a sheetof exterior plywood) suitably braced so that it resides at a 45 a
21、ngle with the horizontal.6.1.1 The frame is to be unpainted with the surface protected from the effects of water and sunlight by varnishing the surface.6.1.2 The supported frame is firmly positioned in a location free from obstruction from trees or other sources of shade. It shallface the equator. I
22、t shall be placed such that no heat or sun light is reflected on it from surrounding buildings. If this is not possible,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 s
23、hall be fastened with care in such a way that undue stresses that could result in premature failureof the geotextile are not induced. Staples may be used.7. Sampling7.1 Lot SampleDivide the product into lots and take one unit per lot as the lot sample.7.1.1 DiscussionThis test method is intended to
24、be performed by the purchaser for the purpose of determine geotextileperformance under site specific conditions. Should a manufacturer perform this test it is not intended that each manufactured lotbe sampled and tested. This is because the test is considered to be time intensive.7.2 Laboratory Samp
25、leTake for the laboratory sample a sample of the geotextile extending the full width of the roll ofsufficient length along the selvedge from each sample roll such that the requirements of 8.1 are met. The sample shall excludematerial from the outer wrap of the roll or the inner wrap around the core
26、unless the sample is taken at the production site at whichpoint outer or inner wrap may be used.8. Test Coupon Preparation8.1 Cut six test coupons for each exposure time in the machine direction 300 by 180 mm (1212 by 7 in.)in. from the laboratorysample. The shortest measurement shall be in the mach
27、ine direction:Machine or Cross Machine DirectionControl 1C1 1C2 1C3 1C4 1C5 1C6Unexposed 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 the shortest measurement in th
28、e cross machine direction.8.2 Cut six test coupons from each direction to be used as control coupons. These will act as the control specimens for allexposure times. Place the control coupons in a black polyethylene bag, and seal to prevent deterioration of the controlunexposedcoupons due to exposure
29、 to ultraviolet light. Store the bag with the coupons in a cool, dry location.9. Procedure9.1 Firmly attach the six coupons for each exposure time to the outdoor test frame as described in 6.2. In the case of staplesbeing used, locate them in the outer 25 mm (1 in.)1 in. of the coupon, with approxim
30、ately four staples per each 300 mm (12 in.)12 in. width, and three staples along each 180 mm (7 in.)7 in. length.NOTE 2If a full sheet of plywood, 1200 by 2400 mm (44 by 8 ft),ft, is used, seven sets of coupons can be attached to the frame. This will allowan approximately 25 mm (1 in.)1 in. space ar
31、ound each sample.NOTE 3The long dimension of the frame and the coupons attached to the frame shall run parallel to the surface on which the frame rests.D5970/D5970M 1629.2 Obtain appropriate weather information, such as average and mean temperatures, amount of rainfall, cloud cover versussunlight, U
32、V index 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 appropriate coupons from theframe and bring them to the laboratory.9.3.1 Condition the coupons in the standard atmosphere for testing geosynthetics.9.4
33、Trim the outer 25 mm (1 in.)1 in. of the long dimension from each side of the coupon such that the remaining materialmeasures 250 mm (10 in.)10 in. in width. Dispose of the trim material.9.5 Carefully cut the remaining 250 mm (10 in.)10 in. wide coupon into five 50 mm (2 in.)2 in. wide, strip tensil
34、e testspecimens. The specimens will measure 180 mm (7 in.)7 in. long.9.6 Prepare the test specimens from the controlunexposed coupons in the same manner.9.7 Determine the breaking strength in kilonewtons per metre (poundspounds force per inch)inch of the exposed andcontrolunexposed coupons, as direc
35、ted in Test Method D5035 using a 50 mm (2-in.) 50-mm 2-in. width strip, except, a CRE orCRT type testing device shall be operated at 305 6 10 mm/min (1212 6 12 in./min)in./min unless specified otherwise. Thedistance between the clamps shall be 75 6 1 mm (33 6 0.05 in.).in. There may be no overall co
36、rrelation between the resultsobtained with the CRE machine and the CRT machine. Consequently, these two breaking load testers cannot be usedinterchangeably.9.8 Record elongation at break.10. Calculation10.1 Determine the average ultimate force and elongation for each exposure time (0, 1,2,4,8,12,18
37、months).10.2 Calculate the average strength for each exposure time as follows:Tavg5Pavg/w (1)where:Tavg = average strength in units of force per unit width kN/m (lbf/in.),Tavg = average strength in units of force per unit width kN/m lbf/in.,Pavg = average force from 10.1, andw = original width of te
38、st specimen, 50 mm (2 in.).w = original width of test specimen, 50 mm 2 in.10.3 Calculate a percent strength retained as follows:Tret5Tavg/Tunexposed!3100 (2)where:Tret = percent strength retained,Tavg = strength of exposed specimens from 10.2, andTunexposed = strength of unexposed specimens from 10
39、.2.10.4 Calculate the average elongation at break.10.5 Calculate the average strain at failure as follows:Savg5Lavg2Lorig!/Lorig (3)where:Savg = average strain at failure,Lavg = average elongation at failure from 10.4,Lorig = original gage length, that is, 75 mm (3 in.).Lorig = original gage length,
40、 that is, 75 mm 3 in.10.6 Calculate a percent strain retained at failure by comparison of the average strain at failure for exposed specimens to theaverage strain at failure for the unexposed specimens as follows:Sret5Savg/Sunex!3100 (4)where:Sret = percent strain at failure retained,Savg = average
41、strain at failure from 10.4, andSunex = average strain at failure for unexposed (control) specimens.10.7 From the results of 10.2, determine the standard deviation and the coefficient of variation for each exposure time, and eachdirection tested.D5970/D5970M 16310.8 Plot graphs of percent strength r
42、etained, percent strain at failure, or modulus versus exposure time, or all of these.10.8.1 Plot graphs of percent strength retained, percent strain at failure, or modulus versus total ultraviolet radiation, ifmeasured, or all of these, for each exposure time.11. Report11.1 Report the following info
43、rmation: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 listing 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 coefficient ofvariati
44、ons 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, and cloud cover versus sunlight, if obtained from weatherstations, for each exposure period,11.1.6 The inclusive dates of exposure for each set of test results, and11.1.7 Th
45、e orientation of the exposure based on the azimuth of the exposed face.12. Precision and Bias12.1 PrecisionThe precision of this test method is being determined.12.2 BiasThe bias of this test method, if any, is being determined.13. Keywords13.1 degradation; geotextile; outdoor exposure; strength ret
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