Effectiveness of a novel composite jacket in repairing damaged reinforced concrete structures subject to flexural loads

Abstract

This study evaluates the effectiveness of a novel composite repair system consisting of prefabricated fibre reinforced polymer (FRP) jacket with joint and grout infill for damaged concrete structures subject to flexural loads. Full-scale beams were prepared and tested under four-point static loads to evaluate the effects of damage location in the concrete member, joint location and internal surface coating of the jacket. The results showed that the behaviour of the repaired system is governed by the tensile cracking of the grout and failing of teeth at the joint. The FRP jacket is found to be more effective in repairing concrete members under flexural load when the damage is located at the top than at the bottom of the member. This effectiveness can be further increased by placing the joint of the composite jacket away from the compression zone. Moreover, the provision of epoxy and coarse aggregates inside the jacket surface resulted in better stress distribution and cracks propagation in the grout than the one without. Finally, a simplified fibre model analysis which considers the confined tensile and compressive properties of the grout reliably predicted the flexural capacity of the damaged beams repaired with the FRP jacket.