Value-oriented SHCC-based strengthening of masonry walls with openings: Integration of glass fiber mesh and steel bars for seismic risk mitigation in construction

Unreinforced masonry (URM) walls with openings are structurally weak under seismic loading because of their low tensile strength, brittle failure modes, and limited energy dissipation, leading to frequent collapses in earthquake-prone regions. This study investigates value-oriented strengthening methods for such walls by integrating strain-hardening cementitious composites (SHCC) with glass fiber mesh and near-surface mounted steel bars as hybrid systems. Nine wall specimens with central openings were constructed and tested under diagonal compression following ASTM E519 standards. Strengthening techniques included SHCC overlays, mesh applied in different orientations, steel bars placed vertically or diagonally, and a hybrid system combining full-surface mesh with diagonal bars. Nonlinear finite element analysis (NLFEA) using ABAQUS was developed and validated against the experimental results, and a parametric study was performed to examine the influence of opening size and opening aspect ratio. Results confirmed that SHCC overlays improved wall ductility, crack control, and load capacity, while reinforcement orientation had a significant influence. The hybrid system achieved the best performance, showing the highest strength, shear stiffness, and up to an eightfold improvement in energy absorption. Parametric results highlighted that a 30% opening area reduced capacity by about 83%. Overall, SHCC-based hybrid strengthening provides a cost-effective seismic retrofitting strategy for masonry walls in heritage and modern buildings. The study further incorporates a risk management perspective in seismic retrofitting of masonry walls and applies a value engineering assessment of retrofitting systems in heritage and high-risk urban environments.