Strengthening of unreinforced masonry buildings with ferrocement composite overlay: Material characterization and numerical study

Abstract

The nonlinear assessment of masonry buildings strengthened with composites is crucial for evaluating retrofitting effectiveness prior to practical implementation. However, numerical tools for analyzing cost-efficient solutions like ferrocement remain scarce. The present study addresses this gap by introducing a simple yet effective 3D macro-modeling approach for simulating ferrocement-strengthened masonry structures. At first, the proposed finite element (FE) model was validated against experimental data, demonstrating its reliability in replicating the lateral load behavior. The validated model was then used to evaluate the efficacy of an optimal ferrocement strengthening configuration implemented in a ‘Splint and Bandage’ arrangement based on standardized guidelines. Relevant material properties essential for this investigation was comprehensively evaluated and utilized in the numerical model. The analysis revealed significant improvements in lateral load performance, including enhanced strength, ductility, and energy absorption capacity, with negligible impact on structural stiffness due to minimal added mass. Additionally, the strengthening effectively transformed the failure mode from a mixed compression-shear-flexural mechanism to a stable flexural rocking mode, significantly reducing stress concentrations and masonry damage. This study demonstrates the effectiveness of ferrocement bands as a cost-effective strengthening solution for unreinforced masonry buildings in seismically active regions. The findings provide valuable insights for optimizing ferrocement strengthening designs, making this approach particularly relevant for improving the lateral load performance of vulnerable masonry structures.