An inelastic model for ultimate state analysis of CFRP reinforced PSB beams

Parallel strand bamboo (PSB) is a bamboo-based composite which is increasingly used to fabricate beams and columns in building constructions. The span of PSB bending member, however, is usually limited in 5 m due to the relatively lower tensile strength and stiffness compared to reinforced concrete (RC) beams. In order to increase the load-carrying capacity of PSB bending members, fiber reinforced PSB beam stratagem was proposed in present study. Flexural performance of PSB beams reinforced with carbon fiber reinforced polymer (CFRP) sheets was studied. Failure modes of PSB bending members with and without CFRP reinforcement were studied by 4-point bending experiments. Test results revealed that the damage of PSB beams presents pronounced nonlinear progressive process. An analytical model, taking into consideration the nonlinear constitutive relation of PSB composite, was developed to estimate flexural performances of CFRP reinforced PSB beams. The results showed that load-carrying capacities of CFRP reinforced beams may averagely increase about 27% compared to unreinforced members. The analytical model can well predict the ultimate load-carrying capacities and deflections of CFRP reinforced PSB beams.