Bond Strength Prediction of Externally Bonded CFRP Laminate with Embedded Connector Through Pull-Out Test of Prism for Shear Strengthening of RC Beam

Embedded connector has been used as anchor of CFRP laminate in recent years for shear strengthening of RC beam. Interfacial bond strength of laminate is required to design the beam for shear strengthening using externally bonded method. The bond strength mostly depends on width of CFRP laminate for particular strength of concrete. The research aims to predict bond strength of CFRP laminate with embedded connector anchor through pull-out test of RC prisms. In the experimental program, a total of 15 RC prism specimens were fabricated. The prism specimens were strengthened using 20, 25, 30, 35, and 40 mm widths of CFRP laminate. Embedded connector of 16-mm-diameter steel was used as anchor in all strengthened prisms. The specimens were tested under pull-out load to predict the bond strength of externally bonded CFRP laminate. Results showed that all externally bonded CFRP laminate had failed by debonding of CFRP laminate at laminate–adhesive interface. The embedded connector anchor was effectively prevented debonding of laminate at concrete adhesive interface. The maximum bond strength of CFRP laminate with embedded connector anchor was 1.52 MPa. The average bond strength of 20 mm, 25 mm, 30 mm, 35 mm, and 40 mm width of CFRP laminates were 1.512 MPa, 1.417 MPa, 1.52 MPa, 1.14 MPa, and 1.157 MPa, respectively. Results also showed that higher width of CFRP laminate exhibited lower bond strength.