Mechanical Feasibility of Asphalt Materials for Pavement Solar Collectors: Small-Scale Laboratory Characterization

Rutting (i.e., depressions along the wheel path) is a distress exhibited by flexible asphalt pavements at high in-service temperatures negatively affecting ride comfort and safety. In this regard, the fine asphalt mortar (i.e., bitumen filler and fine sand) plays a key role in the rutting potential of the asphalt mixtures. Given this background, this manuscript presents a small-scale laboratory experimentation aimed at assessing the rutting-related performance of a plain bitumen combined with natural (limestone) or manufactured (steel slag) fine aggregates (size up to 0.18 mm) through advanced experimental and theoretical approaches. Specific rheological tests through dynamic shear were carried out to achieve this goal. The investigated asphalt blends came from a wider research project focused on the implementation of a pavement solar collector (a road system to harvest the solar energy irradiating the pavement). In particular, the present paper aimed at verifying the mechanical suitability of the produced asphalt mixes with respect to permanent deformation resistance. Such a small-scale investigation mainly showed that the previously selected constituent materials did not imply criticisms in terms of rutting response.