Analysis of strengthening effectiveness of the UHPFRC overlay on the orthotropic steel bridge deck by finite element method

Abstract

In orthotropic steel bridge decks (OSD), high local stresses in the small thickness of steel members are generated by the wheel transverse distribution. In order to reduce the stress level and thereby extend the fatigue life, a strengthening technique with overlaid UHPFRC (Ultra-High Performance Fiber Reinforced Concrete) was commonly used in previous studies. In the current study, three-dimensional finite element analysis with the nonlinear constitutive material model of UHPFRC is performed to investigate the displacements and deformations of steel bridge decks with and without the overlaid UHPFRC. The numerical results are verified by the experimental data. The apparently decreases in displacement and strain levels are observed in both FEM model and experiment, that indicate the beneficial effect of the use of UHPFRC overlay. The influence of the overlaid UHPFRC thickness is also examined in the paper.

Keywords: UHPFR; orthotropic steel deck (OSD); wheel load; finite elment method.