Impact of elevated temperature on the behavior of full-scale concrete bridge deck slabs reinforced with GFRP bars

Abstract

The fiber reinforced polymer (FRP)-concrete composite bridge deck is expected to be a competitive alternative to the reinforced concrete bridge deck owing to its great durability, low weight, and high loading efficacy. The advantages of glass fiber reinforced polymer (GFRP) reinforcement in relation to heated damaged full-scale concrete bridge deck slabs encourage the extension of knowledge regarding the possibilities of combining the GFRP and heated damaged concrete to use the synergy of benefits that can be achieved in the construction and/or rehabilitation of bridges. This study presents a three-dimensional nonlinear finite element analysis (NLFEA) simulating the response of full-scale concrete bridge deck slabs reinforced with GFRP bars. A control slab model was developed initially and properly calibrated and validated against published independent experimental results. A parametric study was then conducted through creating twenty-four NLFEA models with different parameters: type of reinforcement (GFRP and steel), bottom transverse reinforcement ratio (ρ of 0.38, 0.46, and 0.57), and elevated temperature (20 °C, 100 °C, 200 °C, and 300 °C). The GFRP bars reinforcement of bridge deck slabs had superior effects on the ultimate load, elastic stiffness, post cracking stiffness, elastic energy absorption and post cracking energy and a little impact on ultimate deflection compared with steel reinforcement and the efficiency of GFRP bars increased with the heated damage level. Punching shear failure with a very similar cracking pattern was observed almost in all slabs and the bottom transverse reinforcement ratio is the main parameter affecting the tensile strains.