Abstract:To study the effects of parameters such as the position of the post-installed rebar on the mechanical behaviors of a new type of grouted sleeve lapping connector APC (all vertical members precasted in concrete structures), a total of 45 specimens were designed for tensile test. The failure mode, ductility, ultimate bearing capacity, and sleeve strain of the specimens were studied, and ABAQUS was used for numerical simulation and parametric analysis. Test results showed that the initial stiffness and ductility of the connector decreased with the increase in the distance between two rebars. The decrease in the distance between the rebars as well as the contact between the rebar and the sleeve both reduced the bearing capacity of the connector, and the contact between the rebar and the sleeve played a dominant role in the reduction of bonding strength. Under ultimate load, the middle section of the sleeve in the deflection direction (the direction of the line connecting the centers of two rebars) was longitudinally compressed, and the compressive strain increased with the increase in the rebar diameter for specimens with tensile failure of rebars. Under ultimate load, the circumferential strain of the middle section of the sleeve was dominated by tensile strain, and the average circumferential tensile stress increased with the increase in the rebar diameter. Refined numerical simulation of connectors was carried out based on ABAQUS, and the results were in good agreement with the test results. The simulation parameter analysis showed that the deflection reduced the ultimate bearing capacity of the specimen, and had a greater influence on the ultimate bearing capacity of the specimen with pull-out failure of rebar than the specimen with tensile failure of rebar. With the increase in the lap length, the peak value of the bonding stress curve first increased and then decreased, while the fullness of the bonding stress curve first decreased and then increased. The ultimate bonding strength calculation formula obtained from current and previous tests has been verified to be applicable and safe, which can be used as a reference for engineering applications.
