Experimental Study to Design Warm Mix Asphalts and Recycled Warm Mix Asphalts Using Natural Zeolite as Additive for Sustainable Pavements

There are currently various technologies for the manufacture of warm mix asphalts (WMA). This paper presents the possibility of using a natural zeolite to manufacture WMA as an alternative to existing synthetic products for the manufacture of this type of mixture. Moreover, the possibility of manufacturing WMA with the addition of recycled asphalt pavement (RAP) using natural zeolite as the basis of a warm mix technology was evaluated. Firstly, asphalt mixtures were manufactured at three different temperatures (145 °C, 135 °C, and 125 °C) with different percentages of natural zeolite to determine the temperature and the optimum content for the manufacture of WMA. Then, the zeolite moisture content and its release over time were determined at different temperatures, and its distribution in the binder was checked at different concentrations by scanning electron microscopy and fluorescence. Next, with the optimum zeolite content, the addition of RAP between 10–30% in the WMA at the same three manufacturing temperatures was evaluated. Two types of compaction were used: the impact and gyratory compactions. The Marshall parameters were evaluated for all the designed mixtures. The results indicated that the manufacture of WMA with the addition of natural zeolite is feasible, and depending on the required mixing temperature, recycled WMA with different percentages of RAP can be obtained.