Technique for Shear Strengthening—An Experimental Approach

Abstract

This chapter presents the experimental procedure for shear strengthening of RC T-beams strengthened in shear with GFRP sheet. The job is performed primarily in two stages. The first stage consists of selection and testing of relevant materials for the preparation of test specimens in the laboratory to establish the physical and mechanical properties of the materials. All materials are to be tested as per the specifications of Indian Standards. Concrete mix design is to be performed for the preparation of test samples (RC T-beams) as per the design guide lines of IS: 10262 (1982). The mix design for the present case was targeted for M30 grade of concrete. For ascertaining the properties of hardened concrete such as compressive strength, split tensile strength and stress–strain behaviour, tests on cube and cylinder samples, prepared from different batches of mix, were carried out. The second stage consists of testing the beams for shear under two-point static loading system. In the present case, the experimental study was based on the testing of 45 full scale, simply supported RC T-beams of 2.5 m length. Nine beams were used as control specimens with three different stirrup spacing without GFRP wrap and the rest 36 beams were strengthened in shear with GFRP sheets and strips in different configurations, orientations and variation of layers for each variety of stirrup spacing. The tests were performed at the structural laboratory of IIT Kharagpur.