1、Designation:D670706(Reapproved 2011)Standard Specification forCircular-Knit Geotextile for Use in Subsurface DrainageApplications1This standard is issued under the fixed designation D6707;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revisi
2、on,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 specification covers circular-knit geotextiles foruse on the outside of perforated pipes and Class B ge
3、ocom-posites per Specification D7001 in drainage applications.1.2 The tests used to characterize the geotextile are intendedto ensure good workmanship and quality,and are not neces-sarily adequate for design purposes in view of the importanceof environmental factors and specific performance objectiv
4、es.Tests have been selected with essentially neutral aqueoussystems in mind.Other tests may be necessary to establishchemical resistance and durability under the conditions of aparticular application.1.3 This standard may involve hazardous materials,opera-tions,and equipment.This standard does not p
5、urport toaddress all of the safety concerns,if any,associated with itsuse.It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory requirements prior to use.2.Referenced Documents2.1 ASTM Standards:2D123
6、Terminology Relating to TextilesD4439 Terminology for GeosyntheticsD4491 Test Methods for Water Permeability of Geotextilesby PermittivityD4751 Test Method for DeterminingApparent Opening Sizeof a GeotextileD6241 Test Method for the Static Puncture Strength ofGeotextiles and Geotextile-Related Produ
7、cts Using a50-mm ProbeD7001 Specification for Geocomposites for Pavement EdgeDrains and Other High-Flow Applications3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 circular knita structure produced by interloopingone or more ends of yarn or comparable material in acontinuously
8、circular orientation around the fabric.3.1.2 filtrationthe equilibrium soil to geotextile systemthat allows for adequate liquid flow with limited soil lossacross the plane of the geotextile over the service lifetimecompatible with the application under consideration.3.2 Definitions in this standard
9、are in accordance withTerminology D123 and D4439,unless otherwise specified.4.Classification4.1 The circular-knit geotextiles covered by this specifica-tion are classified as follows:4.1.1 Type A:fabric4.1.2 Type H:fabric4.2 The characteristics of the two types of geotextile aregiven in 8.1 below.5.
10、Significance and Use5.1 Circular knit geotextiles have been used extensively formany years as filtration geotextiles in combination with sub-surface drainage pipes.5.2 The test procedures and recommendations referred to inthis standard are considered adequate to determine the accept-able performance
11、 properties of these geotextiles and arerecommended to specifiers and users of these products foracceptance testing.6.Materials and Manufacture6.1 The geotextile shall be manufactured from polymericmaterials.6.2 The geotextiles are manufactured by a circular knitprocess to ensure a consistent,contin
12、uous fabric without seamsalong its machine direction in order to envelope the perforatedpipe without flaws.7.Fabrication Procedures7.1 The circular knit geotextiles,when applied to theperforated tubing,fit snugly and uniformly over the entireexterior surface of the pipe.1This specification is under
13、the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.03 on Perme-ability and Filtration.Current edition approved June 1,2011.Published July 2011.Originally approvedin 2001.Last previous edition approved in 2006 as D670706.DOI:10.1520/D6707-06R11
14、.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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,We
15、st Conshohocken,PA 19428-2959.United States1 7.2 If for any reason the circular knitted geotextile fabricbecomes damaged,repair of damaged area may be conductedin the field prior to installation,by wrapping or overlaying thedamaged area with similar knitted fabric and attaching thefabric either by t
16、ying or with suitable adhesive tape.7.3 The overlaid fabric must be secured in such a manner soas to prevent the patch from moving or shifting during normalinstallation procedures.7.4 The overlaid fabric must cover an area extending aminimum of 45 cm(18 in.)on either side of the damaged areaand must cover the entire circumference of the wrapped pipe inthe area where the repair is being made.8.Physical Requirements8.1 Table of Values:Test MethodType AType HD4491 Water Permittivity2.4 s(-1)min2.75