【国外标准】 Standard Test Method for Degradation of Fine Aggregate Due to Attrition (Withdrawn 2011)

The tendency of some fine aggregates, including those that comply with the requirements of Specification C 33, to degrade from the grinding action in a concrete mixer may affect mixing water demand, entrained air, and slump. When it is suspected that degradation during mixing is a problem, this test method may be useful for evaluating the extent of the problem.This test method is of use for preliminary screening to indicate the need for further evaluation through petrographic examination (Guide C 295) or testing the quality of mortar, or concrete, or both made from the fine aggregate in question.This test method is of use for comparing the results obtained with unknown materials against those with materials of known performance in concrete.1.1 This test method provides a procedure for indicating the relative degree to which a fine aggregate is likely to degrade due to the mixing and agitation of hydraulic cement concrete.1.2 The values given in SI units are to be regarded as the standard. The values given in inch-pound units are for information only.1.3 The text of this test method references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this test method.1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.