ABSTRACT

This paper presents the main results from a project-site investigation to compare the mechanical performance differences between half warm mix recycled asphalt (HWMRA) and a conventional mix (HMA) section in Spain. To this end, HWMRA was manufactured using total recycled contents up to 100% RAP at temperatures below 1000C. This study was therefore performed in three phases. In the first phase, a preliminary laboratory testing analysis was conducted to ascertain the optimal mix design solution through the influence of different curing times in a forced-draft convection oven at 50°C. A second phase assessed the viability of manufacturing these mixes in a discontinuous asphalt mixing plant adapted with a secondary flow-parallel drying drum, while the final phase involved the construction of a road test section formulated with two emulsion contents. At the current time, little difference is seen regarding the performance of the HWMRA compared to the control HMA section.