Study on the mechanical properties of a confined concrete deteriorated by Alkali-aggregate reaction

Recently, in Japan, some concrete structures deteriorated severely by an excessive alkali-silica expansion have been reported and the decrease of compressive strength and Young’s modulus of inside concrete, the fracture and/or yield of steel bar in the bending part have found in these deteriorated concrete structures. On the other hand, in previous studies, it was clear that the structural performance of ASR deteriorated members was not significantly reduced in cases where alkali-silica expansion was appropriately confined by steel bars arranged in the concrete member. However, it is inferred that the influence of Alkali-silica expansion on structural performance of ASR deteriorated concrete member is affected by the confinement ratio of steel bars in a concrete member. In this study, the mechanical properties of the confined concrete deteriorated by alkali- silica expansion were investigated. Thereby, a concrete specimen that had a various confinement level was loaded when these specimens attained at the maximum alkali-silica expansion. As the results, it was cleared that the influence of alkali-silica expansion on the mechanical properties of confined concrete deteriorated by alkali-silica reaction was not significant in cases where the confinement level of concrete member was as much as the normal existing concrete member.