A STUDY OF ALKALI-AGGREGATE REACTION IN CONCRETE - MEASUREMENT AND PREVENTION

The accelerating effects of hot and cold saturated sodium chloride solution on concrete containing alkali reactive (AR) aggregates have been studied. The results show that hot saturated NaCl solution accelerates AR, and the results correlate well with the ASTM C 227-81 and CSA A23.2 14A test results. In cold saturated NaCl solution however, the AR reaction is rock-specific, slow, and judged unsuitable for screening alkali-silica reactive rocks. Although alkali ions introduced from de-icing salts do initiate alkali-carbonate reaction, the rate of reaction is slow under normal temperature conditions. © 1990.