Carbon fiber-reinforced polymer mesh fabric as shear reinforcement in reinforced concrete beams

Abstract

Steel corrosion is a significant threat to the durability of traditional reinforced concrete (RC) members. An effective method of counteracting steel corrosion is replacing steel reinforcement bars in concrete with fiber-reinforced polymer (FRP) bars. However, the FRP bar resists being bent into a stirrup because of its in-situ manufacturing techniques. Moreover, the tensile strength of the bent portion of an FRP stirrup is significantly lower than that of the longer straight bar because of stress concentration. This paper presents an experimental and analytical study on the shear behavior of concrete beams reinforced with a carbon FRP mesh fabric (CFRP-MF) as shear reinforcement for RC members. A new CFRP-MF, which was woven in vertical and parallel directions, as an alternative to the traditional methods used for shear reinforcement, was investigated. Six concrete beams were cast with CFRP-MF as the shear reinforcements, and three concrete beams were cast as controls to investigate the shear behavior of the novel composite beams. The configuration of CFRP-MF and the overlapping condition of the intersection point were the research variables. The test results indicated that these novel composite beams have similar shear capacities and ductilities to traditional concrete beams with steel stirrups. The predictions of the shear strength of the specimens using shear design provisions in ACI 440.1R-15, CSA S6-19 and CSA S806-12 are examined and compared. The finite element method was used to compare the experimental results with numerical values, and the percentage error in all scenarios was lower than 8%.