A micromechanics-rheological approach to study the stiffening mechanism of hydrated lime in asphalt mastics

This research paper provides a comprehensive analysis of the stiffening mechanism induced by hydrated lime in asphalt-filler mastics, integrating micromechanical and rheological theories, which demonstrated to successfully capture the stiffening potential and its temperature-frequency dependency, all through simple and widely available test methods. The experimental results, derived from conventional and fundamental laboratory experiments, substantiate the significant impact produced by hydrated lime on the mastics’ stiffening gain. This increase comes as a partial consequence of the intrinsic filler characteristics such as particle density, surface area and porosity. Similarly, the validation of the GSCS-micromechanics model, based on the volume reinforcement theory and the equivalent rigid layer, by using viscosity, DSR and BBR rheological data supports the hypothesis that the asphalt-filler interaction goes beyond that of a solely physical nature. The results show a definite chemo physical material interaction, which supports the active nature of hydrated lime as suggested by previous similar research.