SHEAR STRENGTHENING OF PRESTRESSED CONCRETE BEAM WITH LARGE OPENING BY CFRP

Abstract

This research presents an experimental investigation of shear strengthening of pretension concrete beams with large circular openings by CFRP. A total of 4 prestressed concrete beams with and without openings were constructed and tested under center-point loading. Test specimen had a cross section of 0.18x0.40 m. and a span length of 3.80 m. Three beams with circular opening had a ratio of  . Experimental results showed that beam with circular opening failed by shear at the lower load capacity of 36.27% compared to the control beam. The externally shear strengthening using CFRP in prestressed concrete beams with large opening in normally strengthening beam and in shear failure-strengthening beam had effectively increased the load capacity of 47.68% and 48.22% compared to the unstrengthened beam respectively. The mode of failure of both strengthened beams were switched from shear failure to flexural failure. Moreover this research proposes the equation for predicting shear strength in prestressed concrete beam with large opening having the accuracy not exceed than 3%