Anchored and epoxied ferrocement strips for improving flexural performance of two-way reinforced concrete slabs

This study investigates an innovative approach to strengthening two-way reinforced concrete (RC) slabs using ferrocement strips strategically placed instead of full layers across the slab area. The research explores the effectiveness of various strip configurations, including orthogonal and diagonal arrangements, bonded with either epoxy alone or epoxy combined with steel anchors. By replacing a portion of the slab's concrete cover with ferrocement strips, this method aims to enhance the load-carrying capacity, ductility, and crack resistance of the slabs while optimizing material usage and minimizing additional weight. Experimental results revealed that all strengthened specimens demonstrated improved ultimate load capacities compared to the control slab, with enhancements ranging from 12% to 33%. Orthogonal configurations consistently outperformed diagonal arrangements, while anchoring the strip ends further increased loadcarrying capacity by 4.1-5.7 %. Adding a second layer of welded steel mesh (WSM) provided modest improvements (5.4-5.9 %) in load capacity. Numerical analysis revealed that increasing the WSM reinforcement ratio, combined with full-length anchoring, shifted the primary failure mode from intermediate debonding (ID) to a more favorable ductile flexural failure. Finite element (FE) modeling complemented the experimental findings by providing valuable insights into stress distribution and failure mechanisms. The model highlighted the progression of stresses leading to ID failure and demonstrated how varying reinforcement ratios and anchoring methods influence the structural performance of the strengthened slabs.