Effects of the use of carnauba wax as a reducing additive mixing and compaction temperatures on the mechanical performance of asphalt mixtures

ABSTRACT

In order to minimize the environmental impact caused by hot asphalt mixtures, the so-called warm asphalt mixtures emerged. This work investigated the use of type 1 carnauba wax, at levels of 1, 2, and 3% by weight of asphalt binder classified with penetration 50/70, as an additive incorporated into asphalt mixtures to obtain warm mixtures. The results showed a reduction of up to 9 °C in the mixing temperature and 7 °C in the compaction temperature with the use of 2 and 3% wax. The asphalt mixtures were dosed by the Superpave method and submitted to mechanical tests: tensile strength tests, induced moisture damage, modulus of resilience, dynamic modulus and fatigue life. The incorporation of 2% resulted in superior results in terms of the mechanical performance of the asphalt mixtures, mainly in terms of induced moisture damage, and a more significant reduction in mixing and compaction temperatures. Therefore, the mixtures complied with the mechanical requirements and were technically viable, contributing to the mitigation of environmental damages such as the reduction of energy consumption and CO₂ emissions in asphalt plants.

Keywords
Warm Asphalt Mixtures; Asphalt Binder; Mechanical Performance; Alternative Material; T-test; Organic Additive