5.1 Riprap and armor material are composed of pieces of natural rock or manmade material that are placed on construction projects, shorelines, streambeds, bridge abutments, pilings and other structures to minimize the effects of erosion. The ability of rock or manmade material to withstand deterioration from weathering affects both the effectiveness of the project and its cost. The specific gravity and absorption provide useful information that can be used in evaluating possible deterioration of rock or manmade material.

5.2 Test specimens equal in size to the proposed design size would provide the best correlations between laboratory tests and actual field performance; however, this is usually neither practical nor economically feasible.

5.3 This test method has been used to evaluate different types of rocks and manmade material. There have been rare occasions when test results have provided data that have not agreed with the durability of rock or manmade material under actual field conditions.

Note 1: Specific gravity is an index property that is an indicator of potential quality (durability). Other features, such as clay mineralogy, crystalline strength, pore (void) spaces and sizes, stylolites, chert bands and nodules, and other micro and macro features may more greatly influence a particles resistance to deterioration in the environment.

5.4 The results of this test is not to be used as the sole basis for determination of durability, but should be used in conjunction with the results of other tests.

Note 2: The quality of the result produced by this standard is dependent upon the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some, but not all, of those factors.

1.1 This test method covers the determination of the rapid specific gravity of rock or man-made materials for erosion control.

1.2 This procedure is intended to be performed in the field, for example, quarry, work site, etc., and as such lacks the accuracy that laboratory method, D6473/D6473M has. For example, there is no requirement for measuring temperature of the water or calculation of the density of water as is required in D6473/D6473M.

1.3 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.4 The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this standard.

1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by this standard.

1.5.1 For purposes of comparing measured or calculated value(s) with specified limits, the measured or calculated value(s) shall be rounded to the nearest decimal or significant digits in the specified limits.

1.5.2 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analytical methods for engineering design.

1.6 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.

1.7 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.