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.
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 1—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/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluation some of those factors
