Finite element modeling of partially-confined concrete and RC columns with embedded hexagonal-FRP strips under axial and horizontal loading

Recently, GFRP-strips partial confinement has demonstrated significant revelations as an effective and economical method of structural rehabilitation and strengthening. In this connection, this paper firstly presents a finite element modeling (FEM) on the behavior of a novel confinement configuration of concrete cylinders with embedded hexagonally designed GFRP strips under axial loading using ABAQUS. The simulation outcomes in terms of stress-strain response and damages were experimentally and analytically validated. The second objective of this paper is to develop a FEM to study a new reinforcement method of large scale partially-confined RC columns subjected to a monotonic horizontal loading. For this purpose, full 3D numerical simulations were carried out taking into account the nonlinear behavior of all used materials. The accuracy of the numerical results was emphasized through a comparison with ones of previous experimental tests. In addition, the effects of various parameters on the failure mode and the ultimate lateral carrying load capacity of the columns were studied on twenty-four numerical models. As main conclusion, the predicted results indicated that the proposed strengthening design with a greater encased-GFRP strip thickness combined with smaller spacing significantly improved the performances of RC columns.