Flexural Behavior of Thin Concrete Slabs Reinforced with Surface Embossed Grid-Type Carbon-Fiber Composites

Fiber-reinforced polymers (FRPs) are being increasingly used to replace rebars as reinforcements for concrete. In this study, the flexural behavior of one-way concrete slabs reinforced with a grid-type carbon FRP (CFRP) (carbon grid), in the form of strands with embossed surfaces, was experimentally investigated. The experimental variables included the effective depth, number of carbon grid layers, and concrete compressive strength. The results exhibit that the surface embossing of the CFRP strands effectively improves their bonding with concrete based on the crack formation pattern. Concrete specimens reinforced with carbon grids exhibited an increased maximum load and stiffness as the effective depth, number of carbon grid layers, and concrete compressive strength increased. Among the experimental variables, the effective depth exhibited the greatest influence on the flexural behavior of the carbon-grid-reinforced concrete specimen. Furthermore, the ratios of the experimental to calculated flexural strength values for all carbon-grid-reinforced concrete specimens ranged from 0.74 to 1.22. Based on the results, a trilinear load-deflection curve was proposed to simulate the flexural behavior of carbon-grid-reinforced concrete members, considering the bond property between the concrete and the carbon grid. The proposed trilinear load-deflection curve reasonably simulated the flexural behavior of the specimens reinforced with carbon grids.