CHEMICAL PROPERTIES AND EXPANDING BEHAVIORS OF ALKALI AGGREGATE REACTION IN CONCRETE

The present report is concerned with model experiments on alkali aggregate reaction with concrete pieces using typical aggregates and adjusting to high alkali condition. It is made clear that a chemical reaction proceeds at a rapid rate when volcanic rocks involving minerals with high alkali-reactivity are used, but does so at a slow rate when sedimentary rocks involving ones with low alkali-reactivity are used. The difference in these reaction rates has influences on the generating process of reaction products and the expanding behavior of concrete pieces. Therefore, the chemical properties of reaction products have come to be utilized to forecast the future concrete deterioration in particular cases.