【国外标准】 Standard Specification for Circular-Knit Geotextile for Use in Subsurface Drainage Applications

This specification covers circular-knit geotextiles for use on the outside of perforated pipes and Class B geocomposites in subsurface drainage applications. Material covered by this specification comprises Type A and Type B fabric geotextiles, which have been used extensively as filtration geotextiles in combination with subsurface drainage pipes. The geotextile shall be manufactured from polymeric materials by a circular-knit process, which will ensure a consistent, continuous fabric without seams. Tests for water permittivity, apparent opening size, and puncture strength shall be performed and shall conform to the requirements specified. Per service requirement, additional tests for chemical resistance and durability may be performed as well.1.1 This specification covers circular-knit geotextiles for use on the outside of perforated pipes and Class B geocomposites per Specification D7001 in drainage applications.1.2 The tests used to characterize the geotextile are intended to ensure good workmanship and quality, and are not necessarily adequate for design purposes in view of the importance of environmental factors and specific performance objectives. Tests have been selected with essentially neutral aqueous systems in mind. Other tests may be necessary to establish chemical resistance and durability under the conditions of a particular application.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.