Bond-slip behaviours between preplaced aggregate concrete (PAC) and steel bars

Abstract

In this article, 54 specimens with diverse types and strength grades of concrete and various embedded lengths and diameter of steel bars were prepared and the bond-slip behaviours between preplaced aggregate concrete (PAC) and steel bars was evaluated by pull-out tests. Then, a bond stress-slip constitutive relationship was proposed on the basis of the thick-walled cylinder model. Finally, the accuracy of the proposed bond-slip constitutive relationship was verified by finite element analysis (FEA) simulation. The results indicated that the bond stress-slip curves could be roughly divided into four sections. The bond strength for PAC under different concrete strength grades were all superior to those for normal concrete (NC). The proposed theoretical model provided a good prediction of bond strength for PAC with reasonable parameters selection. The simulated bond stress-slip curves for PAC were basically in accordance with the testing results which illustrated that the proposed bond-slip constitutive relationship was reasonable. In the future, the accuracy of the evaluation of the bearing capacity of precast concrete structures composed of PAC will be significantly improved by introducing the proposed bond-slip constitutive model.