Bimal Babu Adhikary

Shear Strengthening of Reinforced Concrete Beams Using Fiber-Reinforced Polymer Sheets with Bonded Anchorage

This paper presents results of a study into shear strengthening of reinforced concrete (RC) beams using externally bonded fiber-reinforced polymer (FRP) sheets. The study focused on the effect of extending the length of sheet on the top surface of the beam to delay or prevent sheet debonding. Test variables were the kinds of fibers, the wrapping layouts, and the length of bonded anchorage. From the experiments, it was confirmed that FRP with bonded anchorage is much more effective than the U-wrap scheme. Extending the sheets on a top surface of the beam resulted in a decrease in interface bond stresses and an increase in FRP strain at failure. Four different models for estimating the contribution of FRP sheets to the shear capacity V-sub-f of beams were investigated. Two new equations to calculate V-sub-f are given: when failure occurs due to sheet debonding and when the beams are provided with bonded anchorage at the top face of beams.

Shear strengthening of reinforced concrete beams using steel plates bonded on beam web: experiments and analysis

Abstract Experiments for shear strengthening of reinforced concrete beams using epoxy-bonded continuous horizontal steel plates were carried out. Two control beams and 10 beams with steel plates bonded to their webs were tested. A two-dimensional non-linear finite element analysis is also described. From the experiments and analysis, it was confirmed that continuous steel plates bonded externally to beam webs are effective for the shear strengthening of RC beams. It was observed that the shear strength increases with increasing plate thickness and plate depth. A maximum 84% increase in ultimate shear strength was observed over that of the control beam without steel plates. In the case of relatively thin plates bonded to the beam web, the present numerical analysis accurately predicts the ultimate shear strength as well as overall shear and flexural behaviour.

Numerical simulation of steel-plate strengthened concrete beam by a non-linear finite element method model

Abstract Strengthening with epoxy bonded steel plate is one of the most widely used techniques for flexural upgrading of reinforced concrete (RC) beams. However, debonding failure at the plate cut-off zone and or in the vicinity of flexure and shear cracks leads to catastrophic failure of the upgraded beams. This particular failure depends on several factors such as the distance of plate curtailment from the support, plate thickness and the provision of end anchors. Since the conventional beam theory cannot predict the debonding failure of such beams, a finite element model capable of predicting the overall behavior of strengthened beams including different failure modes accurately is developed. This paper presents the formulation of finite elements and material models and simulation results of some RC beams tested for flexural strengthening with epoxy bonded steel plates.