Grouting sleeve connection under axial loadings: experiment and numerical modelling

Reinforced grouting sleeve connections are widely adopted in prefabricated bridge piers. As one of the most critical reinforcement connection technologies for assembled concrete structures, the reliability of reinforced grouting sleeve connections serves as a key guarantee for the integrity and safety of structures. To investigate the mechanical behaviour of the grouting sleeve connections, uniaxial tensile tests were performed on 12 sets of specimens with different anchorage length of steel bar and water-to-material ratio. Failure mode, bond stress and slip, and load–displacement curves of sleeve connected specimens were explored; additionally, a bond-slip constitutive model was fitted based on test data. Finite-element analysis was also conducted and compared with experimental results. The research results indicated that the fitted bond-slip curve can effectively reflect the bond-slip constitutive relationship of a grouting sleeve connection. For a fixed water-to-material ratio, reduced anchorage length leads to 6.22% and 5.81% drops in yield and peak loads, respectively, while the average bond stress and slip of the steel bar increased, alongside a 29.5% growth in displacement corresponding to the peak load. Compared to the water-to-material ratio, the anchorage length of steel bars exerts a more significant effect on the mechanical properties of the grouting sleeve connections.