SHEAR STRENGTHENING OF R.C. BEANS USING G.F.R.P. LAMINATES

Abstract

In most situations, repairing a structure is far more economic than building a new one. Various strengthening techniques are available for repairing and retro-fitting of structures. A group of high strength materials known as Fiber Reinforced Plastics (FRP) are preferred these days for such work. In this dissertation, the ability of Glass Fiber Reinforced Polymer (GFRP) sheet to improve the shear capacity of a rectangular reinforced concrete beam is examined. An analytical model is used to predict the strength of such retro-fitted beams. Experiments were conducted on a total of twenty one beams which were divided into two sets of nine beams. The remaining three beams were kept as control specimens. The beams in the first set were pre-cracked before repair by GFRP sheet. Three different FRP bonding configurations were employed — strips, U jackets and full wraps. Four point loading was adopted. The load — deflection behaviour, failure strengths and the different modes of failure were observed. The statistical parameters obtained from this experimental work have been used to numerically simulate the strength gain from different modes of FRP bonding configurations. Comparison is done between the experimental data, analytical values and the numerically simulated data.