ASTM_D_5721_-_08_2013.pdf

Designation:D572108(Reapproved 2013)Standard Practice forAir-Oven Aging of Polyolefin Geomembranes1This standard is issued under the fixed designation D5721;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.1.Scope1.1 This practice covers a means for estimating the resis-tance of polyolefin geomembranes to thermal aging in thepresence of air.Only the procedure for heat exposure isspecified,not the test method or specimen.The effect of heaton any particular property may be determined by selection ofthe appropriate test method and specimen.1.2 This practice should be used as a guide to comparethermal aging characteristics of materials as measured by thechange in some property of interest.This practice does notpredict thermal aging characteristics where interactions be-tween stress,environment,temperature,and time controlfailure.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD746 Test Method for Brittleness Temperature of Plasticsand Elastomers by ImpactD1238 Test Method for Melt Flow Rates of Thermoplasticsby Extrusion PlastometerD1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD1525 Test Method for Vicat Softening Temperature ofPlasticsD1790 Test Method for Brittleness Temperature of PlasticSheeting by ImpactD1870 Practice for Elevated Temperature Aging Using aTubular Oven(Withdrawn 1998)3D3045 Practice for Heat Aging of Plastics Without LoadD4439 Terminology for GeosyntheticsE145 Specification for Gravity-Convection and Forced-Ventilation OvensF412 Terminology Relating to Plastic Piping Systems3.Terminology3.1 Definitions:3.1.1 For definitions of general terms used in this standard,refer to Terminology D4439.3.1.2 aging,nthe process of exposing materials to anenvironment for an interval of time.3.1.3 polyolefin,na polymer prepared by the polymeriza-tion of an olefin(s)as the sole monomer(s).(F412)3.1.4 Vicat softening pointthe temperature at which aflat-ended needle of 1 mm2circular cross section will penetratea thermoplastic specimen to a depth of 1 mm under a specifiedload using a selected uniform rate of temperature rise.(D1525)4.Significance and Use4.1 Under the severe conditions of this test,the specimensundergo degradation at a rate that is a function of the thermalendurance of the geomembrane under examination.4.2 The elevated temperature for this practice should repre-sent conditions that are sufficiently severe to induce failure ofpolyolefin geomembranes within an abbreviated period oftime.4.3 The rate of change of a particular property as a functionof temperature may be evaluated using the temperatures andtimes outlined in Practice D3045.4.4 Any correlation between this practice and natural life ofthese materials must be determined for the particular applica-tion in which the materials are to be used.4.5 Air-oven aging can be used to evaluate and compare theperformance of various heat stabilizer packages.1This practice is under the jurisdiction of ASTM Committee D35 on Geosyn-thetics and is the direct responsibility of Subcommittee D35.02 on EnduranceProperties.Current edition approved May 1,2013.Published May 2013.Originallyapproved in 1995.Last previous edition approved in 2008 as D572108.DOI:10.1520/D5721-08R13.2For referenced ASTM standards,visit the ASTM website,www.astm.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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Apparatus5.1 OvenA controlled,forcedventilation oven with sub-stantial fresh air intake is recommended.Oven apparatus shallbe in accordance with Type 11B in Specification E145.NOTE1Cross contamination has been known to occur in rubberproducts.It is not known if it can occur in semi-crystalline thermoplastics.When it is necessary to avoid contamination among specimens ormaterials,a tubular oven method such as Practice D1870 may bedesirable.5.2 Temperature Measuring DeviceA thermocouple orthermometer adequate to cover the range being tested andaccurate to at least 60.5C.6.Sampling6.1 Sampling shall be in accorda