scope:

This test method allows for the detection of potential alkali-silica reaction (ASR) in aggregates within 21 days. In this chemical test method, aggregates are exposed to 1 N NaOH at four different conditions of CaO content and temperature for 21 days following which a reactivity index (RI) is calculated based on the concentrations of specific ionic species in the liquid phase. The RI measured in each of the four testing conditions is used to classify the ASR reactivity of aggregates.

Units-The values stated in SI units are to be regarded as standard.

This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all safety concerns associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.

The quality of the results produced by this standard are dependent on the competence of the personnel performing the procedure and the capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of R 18 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with R 18 alone does not completely assure reliable results. Reliable results depend on many factors; following the suggestions of R 18 or some similar acceptable guideline provides a means of evaluating and controlling some of those factors.