Flexural reinforcement of wood plastic composite panels by bonding glass fiber reinforced polymer sheets and embedding bars

Wood plastic composite (WPC) is a kind of eco-friendly material made of agricultural and forest industry waste and residues compounded with thermoplastic. The defects of traditional WPC, such as low strength and high creep, greatly limit its engineering applications. To solve the problem, this paper proposed two methods of glass fiber reinforced polymer (GFRP) reinforced PVC-based WPC panels (G-WPC) by bonding GFRP sheets or embedding GFRP bars in the tensile zone of the WPC panels. The effects of the thickness of GFRP sheet and reinforcement ratio of GFRP bar on the flexural property of G-WPC were comparatively analyzed by carrying out four-point bending tests and finite element simulations. The results showed that the failure modes of the GFRP sheets reinforced specimens were mainly flexural fracture and interface debonding, and the GFRP bars reinforced specimens were flexural fracture and excessive deformation. The ultimate flexural bearing capacity of both GFRP sheets/bars reinforced specimens could be improved by more than 200%. GFRP bar reinforced specimens had better ductility than reinforced with sheet. The effects of WPC density, GFRP sheet fiber layup angle and GFRP bar diameter on the flexural behavior of G-WPC were further parametrically analyzed using the finite element model (FEM). Highlights: Two effective flexural reinforcement methods of WPC were proposed. The optimum thickness of GFRP sheet was obtained based on experimental tests. The suitable reinforcement ratio of GFRP bars was studied by tests and FEM. Effects of WPC density, GFRP fiber layup angle and bar diameter were analyzed.