Fracture of reinforcing steels in concrete structures damaged by alkali-silica reaction - Field survey, mechanism and maintenance

Abstract

Instances of reinforcing steel fracture in concrete structures damaged by the alkali-silica reaction (ASR) have been discovered recently in Japan. As long as reinforcing steels are not broken due to ASR-caused expansion, the safety of a structure is considered not to be seriously compromised. However, the safety of a structure becomes questionable when the confinement of concrete becomes degraded due to the fracture of reinforcing steel bars. Therefore, it is important to clarify the mechanism of the fracture of reinforcing steel bars and develop methods for detecting steel bar fractures and strengthening concrete structures damaged by ASR. This paper describes the fracture of reinforcing steels in the case of concrete structures damaged by ASR in the Kansai area in Japan. It then introduces the results of investigation on the fracture mechanism, nondestructive testing methods, and repair and strengthening methods for damaged concrete structures. Copyright © 2006 Japan Concrete Institute.