Three-dimensional nonlinear finite element analysis of concrete deep beam reinforced with GFRP bars

The efficient use of FRP reinforcement in deep members has been hindered due to a lack of knowledge on the behavior of such members. Till now, most of researches have mainly focused on the flexural or shear behavior of shallow members longitudinally reinforced with FRP and most of them used testing at small scales. This paper presents numerical investigation of twelve large-scale concrete deep beams internally reinforced with GFRP bars without web reinforcement failed in shear which were experimentally tested and collected from literature. The collected specimens cover several parameters which usually influenced strength and behavior of deep beams as shear span/depth ratio, the reinforcement ratio, the effective depth, and the concrete strength. Concrete deep beams are generally analyzed using conventional methods such as empirical equations or strut and tie models. These methods however do not take into account the redistribution of forces resulting from non-linear materials' behaviors. To address this issue, non-linear finite element analysis that incorporates non-linear material behavior as ABAQUS package is used. It was found efficient in handling such analysis; the proposed simulation of the material in the present study is capable of predicting the real behavior of reinforced concrete deep beam reinforced with GFRP bars in terms of load-deflection behavior, failure load, failure mode, crack propagation, GFRP reinforcement strain, and concrete strain distribution, similar to the tested large scale deep beams.