Modeling of viscous bituminous wearing course materials on orthotropic steel deck

This paper deals with the influence of a bituminous mix surfacing on the orthotropic deck bridges. These researches are part of a French national project "Orthoplus", which is briefly introduced. The approach to take into account the surfacing and to develop calculation tools is explained. First the behavior of the different bituminous constituent materials is investigated. A linear visco-elastic modeling is proposed with a rheological model, previously developed at the Civil Engineering and Buildings Department ("DGCB") of University of Lyon/ENTPE. This model was implemented in a Finite Elements code, which enables the simulation of any orthotropic structures. In order to validate these developments, two orthotropic structures are studied, including the highest bridge in the world, the Millau Viaduct (France). In situ measurements were especially carried out on the Millau Viaduct. The analysis is also performed on the French five-point bending fatigue test used at the EIFFAGE Travaux Publics research center in parallel to the construction, in 2004, of the Millau Viaduct. Focus is made on comparisons between experimental data and simulations results.