Performance control of bituminous mixtures with a high RAP content

To conserve natural resources and reduce greenhouse gas emissions, the use of reclaimed asphalt pavement (RAP) associated with a decrease in temperature coating becomes essential. In order that the incorporation of RAP even at high rates does not impact either sustainability or the mechanical performance of mixture, it is essential to control the homogeneity and the properties of the binder, resulting from mixing between new binder and the aged bitumen (recovered binder coming from the RAP). Through some examples, this paper presents an innovative approach to predict the mechanical performance of recycled asphalt, defines rules for selecting the new binder for high RAP content and thus to prescribe production settings adjustment and mix design, or even to set limits. A study is also made according to the normative context NF EN 13108-1 (Appendix A) for the choice of new binder. A rheological model of module prediction has been specifically developed to assess the modulus of the mixture.