NONLINEAR ANALYSIS OF CONCRETE DEEP BEAM REINFORCED WITH GFRP BARS USING FINITE ELEMENT METHOD

Abstract

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 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 on 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, nonlinear finite element analysis that incorporates non-linear material behavior as ABAQUS package will be used. It was found completely efficient in handling such analysis and the proposed simulation of the material in the present study are 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. Besides, deep beam reinforced with GFRP bars showed different behavior than that of beam reinforced with CFRP bars due to the low elastic modulus of GFRP bars, which was increased dramatically the deflection. Thus, the deflection, instead of strength will govern the design for concrete deep beam reinforced with FRP bars.