Bond–slip behaviour of deformed reinforcing bars embedded in well-confined concrete

Precast concrete beam–column sub-assemblages may exhibit pull-out failure of reinforcing bars embedded in the middle joint when subjected to column removal scenarios. This failure mode has to be considered in analytical study through a component-based joint model. However, current bond–slip models incorporated in design guidelines are incapable of predicting the load capacity and potential failure mode of reinforcing bars with inadequate embedment length in beam–column joints. Therefore, it is necessary to re-evaluate the bond–slip behaviour of embedded reinforcement. This paper presents an analytical approach to predict the force–slip relationship of reinforcement. In the approach, bond stress at the post-yield stage of reinforcement is calculated from existing test data of deformed rebars embedded in well-confined concrete under pull-out loads. The approach is calibrated by experimental results of steel bars with various embedment lengths. Simplified approaches are also developed in accordance with the ...