Asphalts and modified dense bituminous mixtures with rubber of military boots

This article evaluates in the laboratory the physical and rheological properties of the modified asphalt cement (AC) with different contents of rubber (R) from used military boots. For the evaluation of the modified AC, laboratory tests of penetration, softening point, ductility, viscosity, short-term aging and determination of the rheological parameters in the DSR dynamic shearing rheometer were performed. In addition, the mechanical performance of a conventional asphaltic dense mixture (control) and three dense asphalt mixtures with modified asphalt cement with different rubber contents, wet-added, was evaluated by means of monotonic load tests (Marshall Stability) and dynamic (dynamic module). The physical and rheological evaluation of the AC modified with R indicates a significant increase in stiffness as a function of the R content. The asphalt mixtures studied, in reference to the control mixture, presented the same optimum content of asphalt and an increase in the Mar-shall rigidity and dynamic module. Therefore, it was found that the addition of rubber from military boots used in the asphalt cement and later in the mixture, can be considered viable from the technical and environmental point of view, due to the improvement in the mechanical properties of these materials and to allow a form of correct final disposal of the rubber.