Structural behavior of SCC continuous deep beam strengthening and retrofitting with carbon fiber reinforced polymer strips

Abstract

This study presents an experimental work to investigate the structural behavior of continuous self-compacting concrete (SCC) deep beams strengthened and retrofitted with woven carbon fiber reinforced polymer (CFRP) strips and evaluate their shear capacity. The work includes casting and testing fourteen beams specimens. All tested beams have the same dimensions, the same flexural reinforcement and concrete compressive strength with two continuous span and have been subjected to two-point loads. The test specimens were divided into three groups. The first group including eight beams with minimum ratio of shear reinforcement (ρv= ρh=0.25%) and two parameters considered, shear span to overall depth ratio (a/h) and three different schemes of CFRP strip. The second group including four beams without interior vertical and horizontal shear reinforcement (ρv=ρh=0%) with three different schemes of CFRP strip and control beam. The third group consists of two beams with minimum ratio (ρv= ρh=0.25%) were firstly loaded to 65% of the ultimate load of control beams, after that the loads were released and then retrofitted by CFRP strip by two different schemes. The experimental results show that the specimens with vertical CFRP strips an increase in ultimate strength load by 32.6% and 20% compared to the control beams.