【国外标准】 Standard Practice for Preparation of Rock Slabs for Durability Testing

4.1 This practice is used to prepare rock specimens for durability testing and to evaluate any internal defects, such as cracks, that may not be apparent on the surfaces of broken blocks of rock. Such evaluation can also aid in the selection and location of slabs for testing as outlined in Practice D4992. In some cases, the need for further testing or evaluation may be eliminated.4.2 The sawing of rock samples will reduce them to a suitable specimen size and quantity for testing and, in many cases, preserve the natural structure of the internal defects so the samples can be evaluated by the various durability tests.4.3 Durability tests specimens should be 65 ± 5 mm (2.5 ± 0.25 in) thick normal to bedding or any potential planes of weakness which may be observed in the samples. In no case will the size of the slab be less than 125 mm (5 in.) on a side, excluding the thickness Ideally, a test specimen size equal to the proposed design size would provide the ultimate in correlation between laboratory tests and actual field performance. However, in most cases, this is neither practical nor economically feasible.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.1.1 This practice covers the preparation of rock slabs for various tests and any visual inspections used to evaluate the durability of rock for erosion control. These tests include, but are not limited to, Test Methods D5240/D5240M, D5312/D5312M, and D5313/D5313M. This practice is appropriate for the assessment of breakwater stone, armor stone, riprap, and gabion sized rock materials.1.2 Units—The values stated in SI units are to be regarded as standard. The inch-pound units given in parentheses are for information only.1.3 All observed and measured values shall conform to the guidelines for significant digits and rounding established in Practice D6026, unless superseded by this standard.1.4 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice 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 approved through the ASTM consensus process.1.5 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. For a specific hazards statement, see Section 7.1.6 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.