The effects of woven fabric Kenaf FRP plates flexural strengthened on plain concrete beam under a four-point bending test

Abstract

Kenaf fibre possesses excellent tensile strength and elongation at break and is suitable to replace synthetic fibres as reinforcing materials in FRPs composites. This research is aimed to develop an experimental programme to study the behaviour of strengthened concrete beams externally bonded woven fabric Kenaf FRP (KFRP) plates. A four-point bending test was conducted to explore the effects of KFRP plate variation, such as woven fabric architectures, KFRP lengths, KFRP widths, and plate thickness (with cross-ply layers) on plain concrete beams. KFRP plate significantly improved the ultimate load, deflection at peak, stiffness, and performance factor of the strengthened plain beams when kenaf volume fraction and KFRP plate dimensions increased. The best effect to increase plain concrete beam performance was seen in specimen D-PX4 (Series D) with ultimate load, deflection and stiffness are 84 %, 50 % and 36 % with an average performance factor is 103 % compared to control beam. Thus, the flexural strengthening of a plain concrete beam using a KFRP plate is found to be a good alternative technique.

Keywords

• A. Natural fibres
• A. Polymer matrix composites (PMCs)
• B. Stress concentrations
• D. Mechanical testing
• E. Joints/joining