In order to provide a good solution for the treatment and utilization of construction waste, especially waste concrete and to promote the development of green construction to some extent, in this paper, a new composite shear wall filled with demolished concrete lumps (DCLs) and self-compacting concrete (SCC) was proposed, and its seismic performance after fire was investigated. Based on quasi-static tests of four composite shear walls filled with DCLs and SCC, three after a standard fire and one contrastive specimen without fire, the effects of fire exposure time, fire-retardant coating on the edge constraint steel pipe column, and the width-thickness ratio on seismic performance of composite shear walls after fire were studied. The failure patterns, bearing capacity, hysteretic loops, ductility, skeleton curves, rigidity degradation curves, and energy dissipation of shear walls were analyzed and compared. Test results indicate that the bearing capacity of the shear wall after 60 min of standard fire is slightly lower than the contrastive specimen without fire, but specimens still have good seismic performance. The interlayer displacement angle of the shear wall after a fire still meets the requirement of regulations. The fire-retardant coating on the edge of concealed steel pipe column has a limited effect on the seismic performance of specimens after a fire. The horizontal bearing capacity and energy dissipation capacity of shear walls after a fire can obviously be improved by properly increasing the width-thickness ratio.

Performance of fiber-reinforced polymer (FRP)-laminated rubber isolators has been investigated through theoretical and experimental analyses. Effective horizontal stiffness of FRP rubber isolator is analyzed by the cyclic quasi-static experiment. A 1/3 scale shake table tests have been carried out to assess the seismic behavior and the efficiency of the FRP-laminated rubber isolator under the ground motions in different site conditions. The effective horizontal stiffness of the isolator has been derived which has been compared with the experimental results. Experimental studies have shown that FRP-laminated rubber bearings with many advantages can be applied to building structures to enhance seismic capacity.

Rubber bearings are widely used to protect civil structures from destructive earthquakes. The mechanical properties of the bearings are the key technical parameters that determine the seismic isolation performance of isolated structures. To estimate the probability distribution of the mechanical properties related to rubber bearings (including horizontal stiffness, vertical stiffness, post-yield stiffness and yield force) under seismic events. Typical natural rubber bearings (NRBs) and lead-core rubber bearings (LRBs) were designed and fabricated, and the bearings were subjected to repeated load tests using a compression-shear testing machine. The test results of the horizontal and vertical mechanical properties of the bearings in the tests were basically consistent with the design values, and the rubber bearings showed stable mechanical behavior under repeated cyclic loading. The statistical analysis of the test results revealed that the relevant mechanical properties of the NRB and LRB specimens followed a lognormal or general extreme distribution with coefficients of variation mainly ranging from 0.86% to 5.6%. The dispersion of the yield force of LRB was the largest in the repeated tests of many mechanical parameters of typical rubber bearings.

Precast systems are increasingly favored in modern construction to meet the growing demands for faster project delivery, cost control, and enhanced quality assurance. Yet, the feasibility of connections between precast elements remains a crucial factor affecting the overall structural performance of these systems. Considering the versatility and dimensional consistency of structural steel sections, this study introduces an emulative column-to-column hybrid connection achieved by using welding-spliced steel tubes, with a view to improving assembly efficiency and on-site quality control. Reversed cyclic loading tests were conducted on five near full-scale column specimens to assess the seismic performance of the proposed connection. Results indicated that this connection method could provide seismic performance comparable to that of the traditional cast-in-place counterpart. Nevertheless, the anchorage of the column longitudinal rebars played a critical role, as inadequate anchorages led to significant reductions in the columns’ lateral capacity. For this reason, increasing the tube thickness was shown to be insufficient as a substitute for proper anchorage detailing. Moreover, it was found that the incorporation of the welded steel tubes shifted the plastic hinge region upward, resulting in a more extended damage zone—a consequence of the localized stiffening effect. Finally, existing equations and methods are employed to evaluate the lateral strength, load-displacement response, and plastic hinge length of the tested specimens.

A detailed analysis of the seismic safety performance of building structures using X-shaped rubber bearings (XRBs) under seismic action at different seismic levels of intensity were carried out in this study. The horizontal mechanical properties of XRB were studied by analytical methods. To reveal the failure prevention and control capability of XRBs under strong ground motions, a detailed comparative analysis was conducted of the seismic performances of three-story buildings using XRBs, typical rubber bearings (TRBs), and TRBs with retaining wall protection (RWP). A nonlinear dynamic finite element method was used to analyze the displacement, velocity, and acceleration responses of the seismically isolated structures at different ground motion intensity levels. The results show that the failure of the seismic isolation layer occurs in the building using TRBs under seismic intensity with a 1‱ probability of exceedance (PE) in one year. When the RWP is set around the seismic isolation layer, the superstructure will collide with the wall, which leads to a dramatic increase in superstructure acceleration, while the overall seismic isolation performance of the structure is affected. Nevertheless, XRBs can effectively prevent deformation failure of the seismic isolation layer of a building, reduce the seismic response of a superstructure, and can improve the seismic safety level of a building.