Investigation on effective use of CFRP laminates for flexural performance

Abstract

Use of Fiber Reinforced polymer (FRP) materials for strengthening concrete structures is widely gaining appeal worldwide due to its superior properties such as light weight, high strength and stiffness, resistance to corrosion and flexibility. Among those materials, Carbon Fiber Reinforced Polymer (CFRP) has extensive properties over other fiber types; negligible affect by water and high resistance to ultra violet radiations etc. Therefore it is veiy beneficial to use CFRP for retrofitting infrastructures. They can be used to strengthen structures basically for shear, flexure, torsion and confinement of concrete columns. When considering flexural strengthening, there are two main failure modes; classical failure and premature failure. The latter is the most common failure mode. Most of CFRP strengthening systems undergo de-bonding failure before reaching their full capacity. Therefore the frill capacity of CFRP sheet is under-usage. This study was conducted to investigate the effects of CFRP laminate width on performance and premature failure of the system. Seven CFRP strengthened reinforced concrete beams were tested by three point bending test method. This paper presents the test program, results and recommendations.