BEHAVIOR OF R.C.C. BEAM WITH CIRCULAR OPENING STRENGTHENED BY CFRP AND GFRP SHEETS

Mithun Kumar, Shivaraj Mangalagi, Rajendrakumar Harsoor

Abstract: This paper explores the behavior of R.C.C. beam with circular opening strengthened by GFRP and CFRP sheets. In this experimental work ten beams were casted, one beam without opening (i.e. solid beam) and one with circular post opening and considered as control beams. The remaining eight beams were externally strengthened by Carbon fiber reinforced polymer (CFRP) and Glass fiber reinforced polymer (GFRP) sheets with different strengthening schemes i.e. around the opening, inside the opening, inside and around the opening and double layer around the opening. These beams were simply supported and tested less than two points loading in the loading frame. The behaviors of such beams were studied in terms of load carrying capacity, load-deflection behavior and cracking patterns. From the test results it is concluded that the ultimate load carrying capacity of the R.C.C. beam strengthened with GFRP sheets of different schemes were increased in the range of 8.13% to 45.56% and beams strengthened with CFRP sheets increased in the range of 13.01% to 55.32%. Among all the strengthening schemes, the strengthening with CFRP around and inside the opening was found very effective in improving the ultimate load carrying capacity of beam

Keywords: Reinforced concrete beams, Beams with circular opening, CFRP, GFRP, Strengthening schemes, Ultimate load carrying capacity.

DOI: https://doi.org/10.15623/ijret.2013.0213016