4.1 Riprap is a commonly used form of scour protection and general slope protection. Riprap provides a long term solution when properly sized and installed. Riprap has structural flexibility so it will conform to irregular surfaces and adapt to minor subgrade settlement. It is often appropriate for use in conjunction with soil bioengineering (vegetation establishment) alternatives. In some environments, riprap may provide habitat for benthic organisms and fish.

4.2 Revetments provide a facing or lining to armor a surface; and the layer thickness is typically minimized while providing the necessary resistance to scour. In this case, standardized practices to obtain consistent coverage having acceptable thickness tolerances and voids become important.

4.3 This guide may be used by owners, installation contractors, regulatory agencies, inspection organizations, and designers and specifiers who are involved in the construction of riprap revetments. Modifications may be required for specific job conditions. This guide is not intended for construction specifications on large projects, but may be referenced where preparation of job specific construction specifications are not justified. If this practice is included by reference in contract documents, the specifier should provide a list of supplemental requirements.

1.1 This guide covers methods to place riprap with associated filters for erosion control purposes. This guide does not recommend a specific course of action because of the diverse methods and procedures that are capable of producing a functional product. This guide identifies favorable riprap qualities and recommends practices best suited to obtain those qualities. The production of rock, use of recycled materials, rock with cut dimensions, and engineering and revetment design are beyond the scope of this guide. Special forms of riprap, including hand placed riprap, grouted riprap, or keyed (plated) riprap that is tamped into place to smooth the surface, are also beyond the scope of this guide.

1.2 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document 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 ASTM standard 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 document be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this document means only that the document has been developed and approved through the ASTM consensus process

1.3 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

1.4 This standard may involve hazardous operations and equipment. 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.