Investigation of ultimate strengths of concrete bridge deck slabs reinforced with GFRP bars

The corrosion of steel reinforcement embedded in concrete bridge deck has been the cause of major structural deterioration and of high costs in repair and maintenance. Glass fibre-reinforced polymers (GFRP) bars provide a promising alternative reinforcement, which exhibit high durability in combination of high strength and light weight. Due to the low value of elasticity and brittle behaviour of FRP materials, the service behaviour of GFRP reinforced concrete structure is critical in the majority research with FRP bars for reinforcing concrete on simply supported beams and slabs. However, it is recognised that laterally restrained slabs such as bridge deck slabs exhibit compressive membrane action (CMA) which has a beneficial influence on load-bearing capacities and service behaviours such as deflections. This paper presents the results of an experimental study of one-third scaled concrete bridge deck models with several varying structural variables, including supporting beam sizes, reinforcement percentages and reinforcing materials. After the comparison the results of experimental models, the influences from these structural parameters on ultimate strengths and compressive membrane action were evaluated. Furthermore, the improvement of an existing theoretical model for GFRP reinforced concrete bridge deck slabs provided accurate predictions of load-bearing capacities. Consequently, a parametric study has been conducted and the results are discussed.

► CMA enhanced strengths of GFRP reinforced concrete bridge deck slabs.
► Low reinforcement percentages could not influence the behaviours of deck slabs.
► An increase in restraint stiffness is an efficient way to enhance the loading capacities.
► The negative influence from the GFRP material properties was exaggerated.
► The modified theoretical method showed a good agreement with experimental tests.