Fatigue Life Assessment of Orthotropic Steel Deck with UHPC Pavement

Abstract

In recent years, a number of large-span bridges with orthotropic steel decks were constructed in China. With increasing traffic volumes and higher wheel loads, many fatigue cracks developed at the welds and the edge of cut-out holes. This paper aims at presenting the numerical analysis on the fatigue performance of the orthotropic steel deck using ultrahigh performance concrete (UHPC) overlay as the deck pavement instead of the conventional asphalt concrete pavement. By using finite element method (FEM) model, stress distribution at fatigue sensitive locations under the action of wheel loads is characterized and the obtained stress ranges indicate that the UHPC pavement significantly reduces the magnitude of the stress peak valued. A suggested truck stream model based on the weigh-in-motion (WIM) data of four bridges in China is employed to calculate the stress variation at specific fatigue details. Furthermore, the fatigue damage accumulation at fatigue details under the UHPC and conventional asphalt concrete pavement is studied based on Miner’s linear cumulative damage rule and the rain-flow method. The results indicate that the UHPC pavement on the orthotropic steel deck can extend the service lives of the concerned regions over 100 years, but the fatigue lives will reduce significantly when the elastic modulus of UHPC decreases to 50% of the original value.

Effect of Different Ingredients of Ultra High Performance Asphalt Concrete Pavement on Modulus of Elasticity Using Response Surface Modelling

“…As it is clearly visible in Figure 3a, increasing the superplasaticizer decreased the modulus of elasticity that is because of increasing the workability and porosity of concrete [10]. Also, increasing the amount of cement increased the modulus of elasticity of UHPC which is due to increasing of hydration and packing density [11,12]. In Figure 3b, effect of w/c cement were shown on modulus of elasticity of UHPC.…”

Research Progress on Fatigue Reinforcement of Orthotropic Steel Deck

“…By evaluating the case of Fochen West Bridge in China, Zhu et al [10] believed that UHPC-OSD system presents adequate anti-fatigue capability, and that much smaller maximal stress can be expected in all details compared with the previous one. Also, Xu et al [11] concluded that the orthotropic steel deck bridge after the reinforcement of UHPC layer can last for more than 100 years. Hesham et al [12] suggested that the crack formation life rises 236% while applying the UHPC overlayer.…”