Experimental and Numerical Investigation of Two-Way Reinforced Concrete Slabs Retrofitted with Braided Glass/Epoxy Composite Grids

The structural integrity of concrete slabs is a vital concern in civil engineering, necessitating innovative reinforcement and retrofitting techniques to ensure their long-term performance and resilience. This study explores the use of a novel two-dimensional braided glass/epoxy composite grid for retrofitting two-way reinforced-concrete slabs. Through comprehensive numerical analysis and experimental validation, the research aims to assess the effectiveness of this advanced reinforcement technique in enhancing the mechanical properties and stress distribution of retrofitted slabs. The finite-element modeling procedure was validated experimentally using an unretrofitted control slab and a slab retrofitted with a 50×50 mm braided composite grid. A Representative Volume Element (RVE) model is employed to simulate the braided composite grid, providing insights into its advantages and potential challenges. The findings demonstrate significant improvements in load-bearing capacity, energy absorption and overall durability, offering a promising solution for the rehabilitation of aging infrastructure. Within the investigated configurations, braided-grid retrofitting increased the ultimate load by up to 53.62%, with the maximum improvement obtained for the 105 mm-thick C35 slab strengthened using the 100×100 mm grid. This study contributes to the existing body of knowledge by highlighting the practical applications and benefits of incorporating braided composite grid in the retrofitting of concrete slabs.