ABSTRACT
Abstract A large number of old highway bridges are now in need of replacement or some rehabilitations in Japan. The problems are sometimes very serious. These concrete bridges must be rehabilitated, strengthened or upgraded to increase the load carrying capacities. Among the methods used to strengthen or upgrade existing concrete beams are external post-tensioning and epoxy-bonded reinforcing plates etc.. A reinforcement of epoxy-bonded steel plate was one of the major methods for rehabilitation in Japan. Recently new materials, such as fibre reinforced plastics and other composite materials are being applied in reinforcing plate or prestressing cables of concrete structures. Although these new materials themselves show the excellent durability and high strength, the applications to concrete structures are quite few.
