Materials design of CFGFRP-reinforced concretes with diagnosing function for preventing fatal fracture

Abstract

When concretes reinforced by CFGFRP (carbon fiber-glass fiber reinforced plastics) composites containing three types of carbon fiber bundles with different ultimate elongation values are subject to two-point loading tests, the electrical resistance increases linearly with the increase of load, strain and deflection of CFGFRP-reinforced concretes during loading and unloading but when the maximum value of the previous load is exceeded, the increase of electrical resistance becomes non-linear. This behavior is an effective way of knowing the magnitude of the maximum load during loading and unloading. The change in electrical resistance of CFGFRP reinforced concretes during loading increases largely when the carbon fiber bundle is fractured and is maintained thereafter against the increase of external load due to the presence of glass fibers. This behavior can also be used to prevent fatal fracture. Change in electrical resistance can supply better information for damage in concrete structures than strain or deflection. Information on the location of damage can be obtained by comparing the change in electrical resistance of the reinforcing composite at different locations. Concretes using CFGFRP composites as reinforcements are a promising material possessing diagnostic abilities to detect potential damage and to prevent fatal failure.