Analysis of FRP-strengthened RC members with varied sheet bond stress-slip models

Abstract

Finite element analysis was conducted for ten RC specimens, which were shear-strengthened with fiber-reinforced polymer (FRP) sheets. Four of the ten specimens were wrapped with unbonded sheets to observe influence of the bond to the strengthening effectiveness. The tests and analyses demonstrated that the unbonded sheets are not effective to increase the shear strength of a member without steel stirrups while the flexural ductility of a member can be improved by confinement with unbonded sheets. Parametric calculations were attempted with varied interfacial fracture energy Gf and maximum bond stress τy between the sheet and concrete. The calculations indicated that the Gf and the τy have limited influence on the shear strength while the local stresses and crack widths can be controlled to a certain extent.