An Experimental Investigation of Flexural Performance of FRP Reinforced Concrete Slabs

In the study, flexural performances of FRP reinforced concrete (RC) slabs with different fiber and bar surface properties were investigated. Glass fiber reinforced polymer (GFRP), Carbon fiber reinforced polymer (CFRP), Aramid fiber reinforced polymer (AFRP) and Basalt fiber reinforced polymer (BFRP) steel reinforcements were used in the reinforcement of the slabs. A total of 27 slabs were produced in the dimensions of 1100-1100-100 mm and with the same reinforcement ratios as FRP and steel reinforcement and were tested with the four-point flexural test method. The flexural strength, moment capacity, toughness and ductility values of the slabs were calculated by determining their flexural behaviour, and the average values were compared. In the comparison, the behaviour of the FRP RC slabs was analysed by taking the steel RC slabs as reference. The effects of FRP fiber type and bar surface properties on slab behaviour were evaluated. The bending load-carrying capacity of AFRP and GFRP RC slabs with ribbed surfaces was 4% higher than those with sand-coated surfaces. In addition, the bending load-carrying capacity of BFRP and CFRP RC slabs with sand-coated surfaces was 13% and 16% higher than those with ribbed surfaces, respectively. The type of failure in slabs varies based on the type of reinforcement and the surface properties of the reinforcement. Three types of failures have been identified: flexural failure, shear failure, and flexural-shear failure. The ductility performance of steel RC slabs has been determined to be the highest, with a value of 9.45. When comparing toughness, sand-coated FRP bars exhibit toughness levels 8-40% higher than ribbed ones. Among the FRP RC slabs, sand-coated CFRP RC slabs provide the greatest contribution to flexural load-carrying capacities.