STUDY ON PERFORMANCES ON GREEN AND ECOLOGICAL CONCRETE OF NEAR SURFACE MOUNTED (NSM) WITH MPC ADHESIVE BASED ON ECOLOGICALTHEORY

摘要

NSM fiber reinforced polymer (FRP) is a reliable and environmentally friendly rehabilitation and strengthening method for deficient concrete structures. However, it was not applied widely in practice due to some drawbacks of its typical adhesive material-epoxy: longer curing time, higher curing temperature, and instability in light. MPC, an inorganic cementitious blend, appears a fastsetting, higher early strength development, lower setting temperature, good fire and corrosion resistance. As a result, it may improve the applications of NSM using MPC as a new adhesive material. This paper concentrated on a preliminary exploration for the MPC bond performance. A mixture proportion optimization was carried out firstly for extending the MPC’s setting time for casting specimens and improving its lowered bond strength caused by extending the setting time. Then, a total of 12 NSM specimens in 6 sets experienced direct pull-out tests to investigate the feasibility of the MPC NSM system and its different performances with the epoxy NSM system under various curing ages. The results showed that the MPC is proper for NSM system in practice although its bond strength and ductility is weaker than general epoxy. Additionally, the bond strength of the MPC is increasing approximately linearly with the curing age increasing at least before 28 days.