Seismic behavior of load-bearing horizontal-hole interlocking concrete block masonry walls: An experimental investigation of variable configurations

Abstract

The load-bearing horizontal-hole interlocking concrete block (LHIC) represents an innovative approach to masonry wall construction, commended for its impressive bricklaying efficiency and significant mortar savings. To comprehensively evaluate their seismic behavior, six full-scale LHIC block masonry walls, distinguished by varied axial compression ratios, the inclusion or exclusion of horizontal steel bars and concrete tie columns, contrasting mortar strengths, and distinct block types (BC240 vs. BH240), were exposed to in-plane cyclic lateral loads until their point of failure. Diagnostic observations revealed that the wall devoid of reinforced concrete tie columns suffered a unidirectional shear failure, while all other specimens experienced X-type shear failures characterized by diagonal crack patterns. A comprehensive comparative analysis encompassing hysteresis loops, backbone curves, deformation characteristics, energy dissipation, and stiffness degradation yielded critical insights. Specifically, the absence of reinforced concrete tie columns led to a 51.2% and 60.9% reduction in ductility and energy dissipation capacity, respectively, compared to the benchmark specimen. In contrast, elements such as embedded horizontal steel bars, heightened vertical compressive stress, and enhanced mortar strength substantially bolstered the walls' lateral resistance, arrested crack propagation, and decelerated the stiffness degradation, thus fortifying their seismic resilience. The parameter α in the stiffness degradation model serves as a crucial indicator for gauging the rate of degradation, with larger values corresponding to accelerated deterioration rates. Additionally, the introduced relationship for assessing the seismic lateral resistance of LHIC block walls aligns well with experimental findings, demonstrating its aptness for strength evaluation.