USAXS measurements to study the colloïdal structure of asphaltene in aged bituminous samples for recycling purpose of old asphalt pavements.

This study aims at a better understanding of asphalt pavements ageing and recycling which are essential issues for environmental reason.The loss of elasticity of aged bitumen, and the increase of its fragile character favour cracking of roads and could be closely related to the evolution of the colloïdal asphaltene aggregated structure with slow ageing of the bitumen binder in asphalt pavements. We propose to perform USAXS measurements on aged bitumen treated with rejuvenators in order to check there influence on the bitumen colloïdal structure, a major issue for the road construction industry whose goal is to increase significantly the proportion of recycled old pavements for the construction or maintenance of roads. We therefore expect to characterize the multiscaled aggregated structure of the colloidal asphaltene phase of bitumen samples at the 10-1000nm scale, and its evolution with: a) ageing, b) rejuvenating treatments c) temperature at the fluid–viscoelastic transition.