Diagonal compression behaviour of cement-clay interlocking hollow brick masonry walls: Experimental and analytical assessment

In this study, the diagonal compression behavior of cement-clay interlocking hollow brick (CCIHB) masonry walls is investigated using a combination of experimental and analytical study. The four wall configurations on full scales are considered: unreinforced - ungrouted, grouted, reinforced and grouted with vertical reinforcement. Diagonal compression tests were conducted as per ASTM E519 to measure in-plane shear strength, stiffness characteristics and failure modes. An analytical macro-modelling framework consisting of finite element plate representations for the masonry material, material zoning to simulate grout infill and embedded elements to simulate the vertical reinforcement. Analytical predictions are validated based on comparison of load vs displacement response, stress-based failure indicators, shear stress distribution, and global deformation patterns. The analytical results showed good agreement with experimental observations with peak load values predicted within 5% to 8% of measured values. Incorporation of grout infill increased the diagonal shear capacity by about 95% compared to ungrouted configuration and vertical reinforcement increased post-cracking resistance and deformation capacity. The combined grouted and reinforced wall system was shown to have the highest strength, stiffness, and ductility. Stress distribution patterns derived from the analytical models were found to be in qualitative agreement with those experimentally observed crack initiation and failure modes. The results validate the important role of the grout and reinforcement in enhancing the in-plane shear performance of CCIHB masonry walls and demonstrate the suitability of the proposed macro-modelling approach to capture their global structural behavior. This study forms a basis for the validated analysis in the assessment and design of interlocking masonry wall systems in sustainable and modular construction applications.