Coupled Fatigue-Corrosion Failure Analysis and Performance Assessment of RC Bridge Deck Slabs

Abstract

Coupled fatigue and corrosion is more detrimental for RC bridge deck slabs than either fatigue or corrosion separately. The main objectives of this study are to obtain a greater understanding of the deterioration mechanisms and failure modes of RC bridge deck slabs subjected to coupled fatigue and corrosion. Analysis of the joint interaction between chloride-induced steel corrosion and fatigue cracking of concrete is presented. Moreover, the effects of fatigue cracking on the chloride diffusion process and the influences of internal forces redistribution caused steel corrosion on the reinforcement-fatigue stress range were studied. On the basis of the coupled fatigue-corrosion damage mechanism, two fracture-failure modes of concrete bridge decks were proposed and the corresponding limit state functions were deduced. Finally, the performance assessment of an illustrative example shows that the coupled fatigue-corrosion effects obviously reduced the fatigue life of RC bridge deck slabs. It was concluded that the effects of coupled fatigue and corrosion should not be neglected in the fatigue safety design of RC bridge decks.