FINITE ELEMENT ANALYSIS OF UHPFRC CYLINDERS CONFINED WITH CFRP SHEETS

Many recently developed materials have proven their capability as retrofitting materials for different applications. These materials include carbon fiber-reinforced plastic (CFRP) and ultra-high-performance concrete with steel fiber reinforcement (UHPFRC). In this work, the influence of wrapping the UHPFRC cylinders with CFRP was investigated numerically. Different parameters were considered, including the grades of UHPFRC and configurations of CFRP. A 3D finite element model (FEM) of UHPFRC cylinders wrapped with CFRP under static loading was developed using nonlinear finite element software (ABAQUS). The model was first verified using the experimental results provided in the literature. After that, parametric studies were carried out to study the impact of grades of UHPFRC and the different confining CFRP schemes (fully and partially) on the overall behavior of strengthened cylindrical UHPFRC, as well as the impact of increasing the thickness of CFRP layers on the strength and ductility ratio of the confined specimens. The results indicated that using CFRP to warp the UHPFRC specimens significantly improved their strength and ductility. As expected, the use of CFRP to partially wrap specimens did not show a significant enhancement in the strength of the confined specimens when the CFRP layers were less than 60% of the height.