Shear behavior of RC beams with multiple web openings having no shear reinforcement internally reinforced with expanded metal meshes

Sustainable high-rise construction demands solutions that balance efficiency and functionality. Conventional duct placement below beams wastes space and increases costs, whereas incorporating web openings, though efficient, weakens shear strength. Despite extensive research on traditional and composite reinforcement, practical and economical alternatives remain underexplored. This study introduces Expanded Metal Meshes (EMMs) as a novel form of internal shear reinforcement, offering a cost-effective means to enhance the structural performance of reinforced concrete (RC) beams with multiple web openings. Eleven full-scale beams were tested under three-point bending to evaluate the effects of EMM layers (one, two, and three), post-cage reinforcement, upper chord reinforcement, and opening shape (circular versus square). The study examines crack patterns, ultimate shear load, load–displacement behavior, and energy absorption capacity. Finite element models were developed and validated against the experimental results. Key findings reveal that web openings reduced shear capacity by up to 50 % and energy absorption by up to 80 % compared to solid beams. However, EMM reinforcement significantly restored and enhanced performance: beams with three EMM layers achieved 71 % (circular) and 100 % (square) higher ultimate loads than unreinforced counterparts. Post-cage and chord reinforcement further improved shear resistance, with the optimal configuration exhibiting a 45 % increase in load capacity and a 174 % increase in energy absorption. Circular openings outperformed square ones due to reduced stress concentrations, yielding up to 32 % greater strength. Numerical simulations closely matched the experimental data, confirming the model’s reliability. Overall, the findings present a validated, practical reinforcement strategy that enables structural designers to integrate service utilities efficiently, promoting more economical and compact high-rise building designs.