Recommendation of RILEM TC 258-AAA: RILEM AAR-8: determination of potential releasable alkalis by aggregates in concrete

Abstract

The test method AAR-8 is intended to be used for assessing the potential amount of alkalis released by aggregates in field concrete in the long-term. This is done by measuring the amounts of sodium and potassium ions released from the fine graded (< 4 mm) aggregate immersed in (0.7 M) KOH and NaOH solutions, respectively, at elevated temperature when in contact with excess calcium hydroxide. It is of great importance to realise that this accelerated test method must be considered as a mere indication of potential (maximum) alkali release by the aggregates, rather than a quantification used for the alkali inventory calculations.