Experimental study on flexural behavior of GFRP reinforced concrete slabs

Abstract

Remarkable performance of glass fiber-reinforced polymer (FRP) bars make it an ideal candidate for prolonging the life of concrete structure. Although analytical and experimental research of concrete beams strengthened by FRP have flourished in recent decades, it is still in lack of research in comparison with traditional reinforced concrete structures, especially in case of the flexural behavior. In this paper, two groups of GFRP reinforced concrete slabs with different strength grades and reinforcement ratios were experimentally tested, and theoretical calculation method on their bearing capacities was explored. By comparing the deformation and bearing capacity characteristics, the test results were discussed in detail. The calculation formula of flexural capacity of GFRP reinforced concrete slab was derived and then verified against the experimental data. The test results show that the load deflection curve presents obvious double straight lines, and the reinforcement ratio is not closely related to the initial crack load. The cross section still obeys the plane section assumption and the crack distribution is sparse with large width. The flexural bearing capacity coefficient changes from 1.02 to 1.36. Therefore, the limitation of 1.4 times balanced reinforcement ratio in ACI is verified, which could apply a valuable reference for durability design of GFRP reinforced concrete slabs.