5.1 Rock for erosion control consists of individual pieces of natural stone. The ability of these individual pieces of stone to resist deterioration due to weathering action affects the stability of the integral placement of rock for erosion control and hence, the stability of construction projects, structures, shorelines, and stream banks.
5.2 This test method is designed to determine the effects of wetting and drying action on the individual pieces of rock for erosion control and the resistance of the rock to deterioration. This test method was developed to be used in conjunction with additional test methods listed in Practice D4992. This test method does not provide an absolute value but rather an indication of the resistance to wetting and drying; therefore, the results of this test method are not to be used as the sole basis for the determination of rock durability.
1.1 This test method covers procedures for evaluating the durability of rock for erosion control when exposed to wetting and drying conditions on slabs of rock. This weathering test exposes the rock to wetting and drying cycles similar to fluctuating water levels and weather conditions. The rock slabs, prepared in accordance with procedures in Practice D5121, are intended to be representative of erosion control rock and its weaknesses. The test is appropriate for breakwater stone, armor stone, riprap and gabion sized rock materials.
The limitations of the test are twofold. First, the size of the cut rock slab specimens may eliminate some of the internal defects present in the rock structure. The test specimens may not be representative of the quality of the larger rock samples used in construction. Careful examination of the rock source and proper sampling are essential in minimizing this limitation. Secondly, the test requires the rock slabs to be exposed to 80 wetting-drying cycles. The test is time intensive and will require approximately three months to complete the sample preparation, testing, and analysis portions of the procedure.
1.3 Units—The values stated in either SI units or inch-pound units [presented in brackets] are to be regarded separately as standard. The values stated in each system ......
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