The influence of infill ALC walls on the seismic performance of prefabricated PEC T-column frames

Autoclaved lightweight concrete (ALC) is characterized by its light weight, high strength, fire resistance, and sound insulation, and has been widely used in industrial and civil construction. Partially encased concrete (PEC) columns exhibit good load-bearing performance, energy dissipation performance, and outstanding prefabrication performance. In order to study the influence of embedded prefabricated ALC wall panels on the seismic performance of assembled PEC T-shaped column frames, this study conducted low-cycle reversed loading tests on a two-story PEC T-shaped column pure frame and a two-story assembled PEC T-shaped column frame with ALC wall panels. This paper draws detailed comparisons between the failure modes and skeleton curves of the two frames. Analysis of the experimental results indicates that the stiffness contribution of infill walls is primarily affected by local compression and exhibits a negative correlation with the wall-frame lateral stiffness ratio. Furthermore, the presence of ALC walls can significantly increase the initial stiffness of the assembled frame. Therefore, based on the existing theoretical basis, a calculation model and method based on the interaction between infill wall panels and frames are proposed. The frame was numerically simulated using finite element software to study the factors affecting the initial stiffness of the frame, and a relationship formula for the wall stiffness reduction coefficient aw was obtained. The calculated lateral stiffness obtained from the formula was compared with the experimental results of this paper and other studies, proving that the model provides a safe result for the design and application of PEC T-shaped column frames filled with ALC walls, and can provide a reference for engineering practice.