It has been pointed out that the degree of damage of concrete structures due to the alkalisilica reaction varies widely depending on environments. However, there were only a few studies concerning the progress of deterioration on reactive aggregate-bearing concretes under different environments over a long period. In this study, reactive aggregate-bearing concretes were exposed to the two different natural environments. The influence of the environments on the alkali-silica reaction was investigated by measuring expansion and monitoring cracking of them. The concretes having the same mix proportions were stored in a moist environment at 38°C. The difference between the alkali-silica expansion under the natural environments and in the laboratory test was investigated. From the point of view of deterioration of concrete due to the alkali-silica reaction, the exposure test condition under the natural environments was severer than the accelerated test condition in a moist environment at 38°C.
