Chemistry of alkali-silica reaction and testing of aggregates

The fundamental understanding of the mechanism of alkali-silica reaction suggests a simple chemical test method for the evaluation of aggregates themselves. This method has been tested with Danish aggregates and an acceptance criterion has been suggested. Preliminary experiments show that the reactivity of samples of Japanese andesite, British Greywacke, Swedish porphyritic rhyolite, Norwegian mixed aggregate of rhyolite and quartzite and a silicified limestone aggregate from Belgium could be detected within 24 h. This is one of the quickest methods for the evaluation of alkali-silica reactivity of aggregates.