ASTM D7931/D7931M-21

4.1�This guide is intended to aid designers, purchasers, installers, contractors, owners, operators, and agencies in establishing the minimum criteria to specify drainage geocomposites. Specifically, this guide presents a methodology for determining the allowable flow rate of a candidate drainage geocomposite. The resulting value is then compared to a required (or design) flow rate for a product-specific and site-specific factor of safety.

4.2�It is recognized that there are other products that may achieve the same performance requirements but are not listed in this document. Manufacturers of such products are invited to implement this standard guide with the appropriate information.

4.3�It should be recognized that parties, organizations, or representatives may perform additional tests other than those required in this guide. In this case, the more stringent project-specific tests will then take precedence.

4.4�By simulating site-specific conditions (inclusive of site-specific liquids and temperatures except for load duration beyond 100 h, chemical/biological clogging, and geotextile intrusion), additional reduction factors need not be explicitly accounted for in certain products.

1.1�This guide presents a guideline specifying a drainage geocomposite product; it specifically provides recommendations to determine the allowable flow rate of a candidate drainage geocomposite. The resulting value is then compared to a required (or design) flow rate for a product-specific and site-specific factor of safety.

1.2�This guide is intended to aid designers, purchasers, installers, contractors, owners, operators, and agencies in establishing minimum guidelines for drainage geocomposite materials. This guide is not to be used for manufacturer’s quality control purposes, nor is it a construction quality assurance specification.

1.3�This guide does not address the required (or design) flow rate value, nor the subsequent factor of safety values, which are typically design specific.

1.4�The procedures recommended in this guide use ASTM test methods.

1.5�This guide is applicable to all types of drainage geocomposites regardless of their core configuration or geotextile type. It can also be used to evaluate thick, nonwoven geotextiles that provide drainage.

1.6�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 nonconformance with the standard.

1.7�This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This guide cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This guide is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this guide be applied without consideration of a project’s many unique aspects. The word ‘standard’ in the title of this guide means only that the guide has been approved through the ASTM International consensus process.

1.8�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.

1.9�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.