Influence of reinforcement parameters on punching shear capacity of laterally restrained FRP-reinforced concrete bridge deck slabs

Previous experimental and numerical research studies have investigated the behavior of laterally restrained FRPreinforced concrete bridge deck slabs under wheel loading. Existing punching shear models are limited in their degree of accuracy due to the normalization approach and lack of consideration of all reinforcement parameters. This paper reiterates the established parameters (i.e., longitudinal and transverse bars' spacing and size) and assesses their influence through a numerical study to develop an empirical formula for calculating the punching shear capacity. The results revealed that the bar spacing has more influence than the bar size on the punching shear capacity; thus, normalizing the reinforcement amount into the reinforcement ratio, rho, is no longer valid. An empirical punching shear capacity formula is developed herein using data collected from three previous experimental studies. The rationality of the developed formula was examined and tested based on experimental and numerical models. Moreover, the results obtained by the developed formula were compared with available punching shear models, which testified about the accuracy and effectiveness of the developed formula.