Strengthening of reinforced concrete columns using FRP fabric

Abstract

In a number of cases, the compressive strength of reinforced concrete members have been found to be less than the design strength. Therefore, forcing the structural engineer to strengthen these members in order to cater for the dead, superdead and superimposed loads to which these structural members are subjected to throughout their service life. In the case of under-strength columns, an efficient method of increasing the strength and ductility of these columns is by wrapping them with fibre-reinforced polymer (FRP) fabric. However, most previous studies on concrete short columns confined with FRP sheets were based on small-scale testing which did not take into consideration the size effect of these columns. In this study, 40 MPa concrete cylinders having height-to-width ratios (?) of 4 and 8 are wrapped with CFRP sheets impregnated with epoxy and tested under uniaxial compression. Their ultimate failure loads are recorded and the performance of the wrapped cylinders is compared to the unwrapped control specimens in terms of the strength gain produced by the confining effects of the wraps.