The Advanced Countermeasures of Prevention for Concrete Pieces Falling at Concrete Structures in Japan

摘要

Recently, it is serious social issue to be of frequent occurrence of concrete pieces falling from elevated bridges of highway, railway and tunnels in Japan. Concrete pieces falling brings the great damage to the passing cars and the foot passers and sometimes many people as the third party are perished in the accidents. The importance of countermeasures for preventing concrete pieces falling is recognized and the effective and practical countermeasures not only for existing structures, but also newly build ones have been adopted and applied. In this study, the current status of the effective and practical countermeasures for prevention of concrete pieces falling at concrete structures in Japan is introduced. From the viewpoints of materials, structural design and construction, the causes of concrete pieces falling were investigated. Subsequently, continuous fiber sheet bonding method constituted of three axial vinylon fiber and concrete polymer composites as typical countermeasure was proposed and its verification was discussed.