Elevated temperature thermomechanical behaviour of near surface mounted CFRP reinforced concrete specimens: Effect of adhesive at concrete/CFRP interface

In civil engineering, fire concern is always a strict constraint to FRP reinforced structure in general. The main objective of this study is to experimentally study the effect of adhesive at concrete/CFRP interface on thermomechanical behaviour of near surface mounted CFRP reinforced concrete specimens under elevated temperature condition. The specimens are subjected to simultaneous combination of mechanical load and elevated temperature that is close to fire condition. In this study, the CFRP is bonded to concrete using three adhesives: one common epoxy for ambient cured temperature, one high temperature performance epoxy and one cement-based adhesive. In experimental test, the sample is firstly loaded by a pre-defined and fixed mechanical load, and then the temperature surrounding the sample quickly increases until failure. The failure temperature and the thermal exposure duration are then analysed to identify the performance of specimen under simultaneously combined temperature-mechanic load. The results show that the two epoxies, compared to cement-based adhesive, can perform in wider range of mechanical and temperature condition. It is also shown that the thermomechanical performance of CFRP reinforced concrete can be optimized by choosing appropriate type of epoxy under certain designed mechanical load.