Mechanical Performance of Timber Beams Reinforced by FRP Sheets

Abstract

In order to improve the mechanical performance of timber beams, five rectangular-section beams were used in flexural test and ten for shearing. The effects of FRP types i.e. CFRP, BFRP and AFRP, layers of FRP sheets and the way FRP sheets pasted were studied. The failure pattern, load-deflection curve, strain distribution and ultimate load capacity of the specimens were analyzed. The results indicate that the ultimate load carrying capacity of beams were increased by 15.4% to 55.1% varyingly with the reinforcement of FRP, besides, the stiffness and ductility were improved also. The improvements were lower in the specimens with material defects such as the existence of knags and shrink cracks. It’s more effective to paste the FRP sheets slantingly with the angle of 45° than vertically. However, the effect on the initial stiffness is not distinct whether reinforced or not. The analysis of strain and stress distribution manifests that the plane cross-section assumption is efficient in design and calculation of FRP reinforced timber beam.