Experimental Investigation of Axial Load and Detailing Effects on the Inelastic Response of Reinforced-Concrete Masonry Structural Walls with Boundary Elements

Abstract

In typical wall load-bearing reinforced-masonry (RM) buildings, the lateral and vertical forces are resisted by rectangular shear walls. Thus, the walls are subjected to high vertical forces from gravity loads that are expected to limit the displacement and energy dissipation capacities. Moreover, the rectangular RM shear walls have limited lateral stability because of the single vertical reinforcement layer. The intent of this study is to investigate the inelastic cyclic response of RM structural walls subjected to axial compressive stress that results in precompression ratios, P/Agfm′, higher than 10%. The main objective is to propose practical component-level seismic detailing recommendations to enhance the overall structural performance. In this respect, three half-scale, fully grouted RM shear walls were tested under constant axial load, in-plane fully reversed cyclic loading, and top moment. The tested specimens are flexural dominant to simulate the response of mid and high-rise RM shear walls under strong seismic actions. The walls were designed to have enlarged boundary elements built using C-shaped blocks to evaluate the ability of end zone detailing and confinement to alleviate the impact of the high axial load. The test results demonstrated an overall enhanced structural performance for the three walls. The three specimens attained high ductility levels, high energy dissipation capacity, and failure in the ductile flexural mode. The presence of the well-detailed and confined boundary elements was effective in mitigating the impact of the high axial compression load. Thus, utilizing this type of masonry shear wall increases the competitiveness of masonry buildings as an alternative construction method.