Thermo-mechanical behaviour of mixtures containing bio-binders

The objective of the presented study is to develop an approach to assess the linear viscoelastic (LVE) properties and the low-temperature behaviour during thermal ageing of semi-coarse asphalt concrete (SCAC) containing bio-binders. The investigation is part of a wider ongoing research project in EIFFAGE Travaux Publics Research Center. Tension/compression complex modulus tests, direct tensile strength tests at low temperatures and thermal stress-restrained specimen tests were performed on SCAC, containing three different clear binders. The first one is a reference petroleum-based clear binder, the two others are bio-binders, manufactured from renewable raw materials and fit in with the ideas of sustainable development. The analogical LVE 2S2P1D model (2 springs, 2 parabolic elements, 1 dashpot) was used to fit experimental data for the three mixtures. This method seems to be very relevant to compare rheological properties of mixtures made with bio-binders, for which evolution of low-temperature behaviour with ageing is very discriminatory.