Failure Behaviour of Concrete Prisms Strengthened by Various Bond Widths of Carbon Fibre Reinforced Polymer (CFRP)

Abstract

The use of fibre reinforced polymers (FRP) for external strengthening of concrete structures in various forms such as laminates and sheets has become moderately common. FRP is more effective as it provides a better solution in terms of properties and application. The effectiveness of the FRP strengthening system lies in the bond between concrete and FRP which is affected by various factors such as bond length of FRP, bond width, resin hardening and surface preparation. In certain cases, bond width is a major factor which ensures that the structure can be strengthened properly. This paper focuses mainly on the failure behaviour of concrete prisms strengthened by various bond width ratios of carbon Fibre Reinforced Polymer (CFRP) which are 20mm (0.27), 40mm (0.53), 60mm (0.8) and 75mm (1) respectively. A total of fifteen strengthened prisms measuring 75 mm × 75 mm × 350 mm were cast for a three-point load test. Twelve strengthened prism specimens were externally strengthened with CFRP and three specimens were designated as control. The findings show that a greater width ratio of CFRP will strengthen concrete prisms greatly and will result in different types of failure modes.