Case Study on Deterioration of Concrete in Road Structures due to Alkali-silica Reaction (ASR) in Hokuriku Region and its Evaluation Methods

In this study, the relationships between the percentage of reactive andesitic aggregates contained in river gravel, the alkali and chloride content in concrete and the degree of deterioration of concrete due to ASR in Hokuriku region were investigated by means of the visual inspection for concrete structures and the various tests using the cores taken from them. The applicability of accelerated curing method according to the Canadian and Danish specification to evaluate the alkali-silica reactivity of aggregate or the residual expansion ability of concrete was comparatively examined. By judging from the results of inspection whether or not the expansion of ASR-affected concrete structure had already been stopped, the appropriate repair and maintenance method should be adopted for the individual one.