Pull-Out Behavior of CFRP Bars in Glued-In Glubam Joints

Abstract

Glubam (glued-laminated bamboo) is a newly developed structural material with properties comparable to other wood and wood-based materials. Fiber-reinforced polymer (FRP) bar is an attractive reinforcement due to its lightweight, high strength, and high corrosion resistance. In order to explore the merits of combined utilization of glubam and FRP bars in structures, pull-out tests of carbon FRP (CFRP) bars glued-in glubam were conducted. The bond behavior, failure modes, strength, and stiffness of glued-in CFRP bar glubam joints were investigated. The main experimental parameters included glue-line thickness, anchorage length, and the angle between the bar and bamboo fiber. The test results illustrated an increasing tendency of peak loads with the anchorage length, glue-line thickness, and angle. The complex relationships between the bond stress and three influencing parameters were discussed. A simple analytical model was derived and shown to be capable of capturing the initial bond stress–slip behaviors of glued-in CFRP bar glubam joints. Finally, a design equation for estimating the pull-out strength of the CFRP bar in glued-in glubam joints was proposed based on the modification of an existing code equation.