FLEXURAL BEHAVIOR OF OVER REINFORCED HSC BEAMS CONFINED BY RECTANGULAR TIES

Abstract

This paper presents an experimental and analytical investigation on the flexural behavior of over reinforced concrete beam confined by rectangular ties. The experimental investigation was conducted through testing four full-scale beams with normal strength concrete (NSC). Three out of these four beams were confined using rectangular ties located on the compression region of the beams. The variables studied in these specimens were the volumetric ratio of transverse reinforcement, and the volumetric ratio of the main rebars. A finite element model was established with both material and geometrical non-linearity by using ANSYS software package. Accuracy of the model was assessed by applying it to the three tested beams. Comparison of analytical results with the available experimental results for ultimate load values and load– deflection relationships show a good agreement between the finite element and experimental results. After validating the accuracy of the proposed model, parametric study was undertaken to gain additional insight into the overall behaviour, failure modes, and deformation capacity for the concrete beams using high class concrete strength. The parameters studied were, the concrete compressive strength, the number and diameter of longitudinal rebars, and diameter of rectangular ties. The obtained results show that, the strength and ductility of high strength concrete (HSC) beams are enhanced through the application of rectangular tie reinforcement located in the compression region of the beams. The concrete compressive strength, the longitudinal bars number and diameter, and the diameter of rectangular ties are important parameters controlling the level of strength and ductility enhancement of overreinforced HSC beams.