Performance of a lightweight GFRP composite bridge deck in positive and negative bending regions

This paper presents results from an experimental and analytical study of a newly developed lightweight composite bridge deck system composed of pultruded trapezoidal GFRP tubes and outer wrap. Panels with different grout materials and grouting patterns were evaluated and compared in terms of flexural stiffness. Two-span tests were performed on non-grouted and epoxy grouted panels to simulate a multi-girder bridge configuration and to evaluate their structural behavior in both positive and negative bending regions. Test results showed that the epoxy grouted panel meets the AASHTO deflection requirement (L/800) and performed well under service loads. An analytical model was developed to predict the load–deflection response of grouted and non-grouted panels at incremental load steps, even beyond the uncracked stage. The proposed model shows that shear deformation must be considered in order to accurately predict the behavior of GFRP panels in multi-girder bridges.