The sleeve grouting connection is the most common form of vertical connection for prefabricated shear walls. However, during construction, this type of connection is prone to defects such as insufficient anchorage length of reinforcement, deviation of reinforcement, and insufficient amount of sleeve grouting, which significantly impact the integrity and seismic performance of the prefabricated shear wall structure. The finite element analysis of the prefabricated shear wall with sleeve grouting connection is still based on solid element modeling. This method has the disadvantages of complex models and low computational efficiency. In this paper, a simplified modeling method for prefabricated shear walls considering sleeve grouting defects was proposed to address this issue. Firstly, the equivalent constitutive relationship of the sleeve grouting defect connector was constructed based on the uniaxial tensile test of the existing sleeve grouting defect connector, and the T3D2 element was used to simulate the sleeve grouting connector. Then, the mechanical behavior of the horizontal joint between the shear wall and the foundation beam was simulated by the cohesive force model, and the prefabricated shear wall models with sleeve grouting defects were established. The accuracy of the simplified modeling method was verified by comparing the experimental results and numerical simulation results of the seismic performance of the prefabricated shear wall with sleeve grouting defects. The results showed that the hysteresis curve, skeleton curve, and failure mode of the numerical simulation were in good agreement with the test results. However, the stiffness of the concrete degenerated rapidly due to the apparent development of plastic-damaged concrete, which made the falling section of the hysteresis curve of the numerical simulation different from that of the test. The proposed simplified modeling method can be further applied to the performance study of prefabricated shear walls with sleeve grouting defects and can provide a reference for structural performance evaluation, design optimization, and construction quality control to a certain extent.

This research focuses on the seismic performance of post-fire sleeve-grouted connection prefabricated shear walls. The effects of fire duration, axial compression ratio, aspect ratio, and longitudinal bar diameter on the failure mode, horizontal bearing capacity, ductility, and energy dissipation capacity of post-fire sleeve-grouted connection prefabricated shear walls were analyzed using the ‘sequential thermo-mechanical coupling’ method. The research results indicate that the failure mode of post-fire sleeve-grouted connection prefabricated shear walls undergoes significant changes, with damage mainly concentrated in the horizontal joints and the area above the sleeves. As the duration of fire increases, the damaged area gradually extends upwards until the bearing capacity is lost. With the increase in fire duration, the peak and failure loads of post-fire sleeve-grouted connection prefabricated shear walls show a significant downward trend, and the ductility decreases by 7.98%, 12.17%, 15.21%, and 20.15%, respectively. When the axial compression ratio is less than 0.3, both the horizontal bearing capacity and ductility of post-fire sleeve-grouted connection prefabricated shear walls increase with the increase in axial compression ratio. However, when the axial compression ratio exceeds 0.3, the horizontal bearing capacity and ductility of post-fire sleeve-grouted connection prefabricated shear walls decrease with the increase in axial compression ratio, and the failure mode of post-fire sleeve-grouted connection prefabricated shear walls transitions from flexural-shear failure to flexural failure as the axial compression ratio increases. As the aspect ratio increases, the energy dissipation capacity of post-fire sleeve-grouted connection prefabricated shear walls increases, but the horizontal bearing capacity and ductility decrease. Increasing the diameter of longitudinal bars can improve the horizontal bearing capacity of the specimens but reduce the ductility and increase the energy dissipation capacity. The research results provide a theoretical basis for the safety assessment, repair, and reinforcement of post-fire sleeve-grouted connection prefabricated shear walls, and have important reference value for practical engineering applications.

As a critical element within the prefabricated structural system, the prefabricated shear wall connected by sleeve grouting is renowned for its superior mechanical performance and high construction efficiency. It is widely applied in mid- and high-rise buildings. However, under fire conditions, not only do the material properties degrade, but the structural connections may also fail, significantly compromising the structural stability and safety. Therefore, this study delves into the fire resistance performance of such prefabricated shear walls. The research primarily focuses on analyzing fire resistance characteristics, including deformation patterns, lateral and axial deformations, fire resistance limits, and other performance metrics, for both prefabricated and cast-in-place shear walls subjected to three hours of single-sided fire exposure. Additionally, a parametric analysis is performed. The results reveal that, after three hours of single-sided fire exposure, the temperature distribution patterns at the mid-width and mid-height sections of the prefabricated shear wall generally resemble those of the cast-in-place wall, displaying arch-shaped and strip-shaped distributions, respectively. However, due to the presence of sleeves, higher temperatures are observed near the sleeve areas in the prefabricated wall, along with a more extensive high-temperature zone. Throughout the three-hour fire exposure, both types of shear walls demonstrated satisfactory structural stability and thermal insulation performance, meeting the requirements for a first-level fire resistance rating (3 h). Nevertheless, greater axial and lateral deformations were noted in the prefabricated shear wall. Key factors influencing the fire resistance performance of the sleeve-connected prefabricated shear wall include the axial compression ratio, longitudinal reinforcement diameter, protective layer thickness, and height-to-thickness ratio. Specifically, axial deformation is found to be directly proportional to the axial compression ratio and height-to-thickness ratio, while inversely proportional to the longitudinal reinforcement diameter and protective layer thickness. Lateral deformation is directly proportional to the axial compression ratio and longitudinal reinforcement diameter, and exhibits a trend of initially increasing and then decreasing with an increase in protective layer thickness, and initially decreasing and then increasing with an increase in the height-to-thickness ratio.