This method describes the procedure for determining the durability of aggregates. The durability index is a value indicating the relative resistance of an aggregate to produce detrimental claylike fines when subjected to the prescribed mechanical methods of degradation. The values stated in SI units are to be regarded as the standard. The values given in parenthesis are for information only. This standard may involve hazardous materials@ operations@ and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.