ABSTRACT
The analysis of the bond properties of plain rebars to concrete is of great significance for the identification and strengthening of historic buildings. This study investigates the bonding mechanism of plain rebars to concrete through theoretical analysis of pull-out tests. The normal stress at the contact interface due to the difference in Poisson’s ratio between reinforcement and concrete and the resulting bond stress are quantified through the combination of elastic mechanics and fracture mechanics. The energy release rate is introduced in the analysis to elucidate that when the crack extension force is greater than the frictional resistance at the debonding interface, the bond-slip curve will drop precipitously after reaching the peak point (cliff type), and conversely the curve decreases slowly under abrasive wear (slope type). According to the theory, the bond-slip curve of plain rebar and concrete can be predicted.
