Arching Action Contribution to Punching Failure of GFRP-Reinforced Concrete Bridge Deck Slabs

The punching strength and failure mode of concrete deck slabs reinforced with glass fibre-reinforced polymer (GFRP) bars, including arching action contribution to punching failure, is studied experimentally and theoretically in this paper. The experimental study included static tests on one-third scale deck specimens. Failure mode, loading–carrying capacity and structural behaviour observed in this test are discussed and used to investigate the contribution of arching action to punching behaviour. The test results revealed that increasing the lateral restraint stiffness resulted in higher punching strengths and lower GFRP reinforcement strain. This is due to the enhancement of aching action. In addition, the failure mode of deck slabs was varied from flexural punching failure to shear punching failure by the higher contribution of arching action. The test results and results from the literature were used to assess the accuracy of the existing punching-strength prediction models. The predicted strengths from a theoretical procedure based on arching theory developed by the writers showed better correlation with experimental results compared to those from other analytical models. Thereafter, a series of parametric studies in this method were conducted to investigate the influence of arching action on the failure mode of GFRP-reinforced concrete deck slabs. Some design recommendations for punching-strength design in GFRP-reinforced concrete bridge deck slabs were proposed to avoid the rupture of FRP bars.