Experimental and numerical investigations on the performance evaluation of shear deficient and GFRP strengthened reinforced concrete beams.

The present study is focused on the experimental investigation and nonlinear finite element simulations of shear deficient and glass fibre reinforced plastic (GFRP) strengthened reinforced concrete beams. Three levels of shear deficiency are considered in the design. Two layers of GFRP fabric are used for strengthening in the shear zone. The behavior of control, shear deficient and GFRP strengthened beams under two-point monotonic loading is studied. Detailed 3D non-linear finite element analyses with perfect bonding as well as with cohesive zone modelling are carried out to simulate the behavior of shear deficient beams. The responses, in terms of load-deflection behavior, failure loads and crack patterns, obtained from numerical simulations are validated with that of the experimental investigations. The validated numerical models are then used for studying the efficacy and effectiveness of various strengthening schemes using epoxy impregnated GFRP fabric where the number of layers, orientation and distribution of fibres are considered as parameters. Based on the parametric studies, the schemes which provide optimum improvement in performance for strengthening of the shear deficient beams are identified. For all three classes of deficient beams, greatest improvement in strength is attained for 45° orientation in single ply, 45°–90° orientation in double ply and 90°–45°–90° orientation in triple ply strengthening schemes. In all GFRP strengthened beams, mode of failure changed from shear to flexural failure and showed great improvement in the ductile behavior. [ABSTRACT FROM AUTHOR]