J.P. Firmo

Bond Behavior between Near-Surface-Mounted CFRP Strips and Concrete at High Temperatures

AbstractThis paper presents an experimental study concerning the bond behavior at high temperatures between concrete and carbon fiber–reinforced polymer (CFRP) strips installed according to the near-surface-mounted (NSM) technique. Double-lap shear tests were performed on concrete blocks strengthened with CFRP strips installed into slits and bonded with either an epoxy adhesive (series EP) or a mixed grout composed of epoxy and cement binders (series MG). Specimens were first heated up to predefined temperatures (from 20 to 150°C, measured in the adhesive) and then were loaded up to failure. The obtained results allow drawing the following conclusions: (1)xa0the axial strains along the bonded length became closer to linear (at high temperature) because of the softening (glass transition) of the bonding materials; (2)xa0the effective bond length increased for elevated temperature; (3)xa0the bond-slip curves exhibited considerable and consistent stiffness and maximum shear stress reduction with temperature; (4)xa0t...