Volumetric Properties of Warm Rubberized Mixes Depending on Compaction Temperature

Abstract

The hot mix asphalt (HMA) industry is commencing on a program to substantially decrease mix production temperatures. Reduced mix production and paving temperatures would decrease the energy required to make HMA, reduce emissions and odors from plants, and improve the working conditions at the plant and paving site. With regard to rubberized asphalt mixtures, they are produced and compacted at higher temperatures than conventional mixtures. If the technologies of warm mix asphalt are incorporated, it is expected to reduce the mixing and compaction temperatures of rubberized asphalt mixtures to those of conventional mixtures. This study was initiated to investigate the effect of compaction temperature on warm rubberized mixes. For this, two Superpave mix designs for two asphalt binders and one aggregate size (12.5mm) were conducted to determine the optimum asphalt contents (OAC). Warm rubberized mixes were produced using two of the available processes. A total of 96 specimens (4 mix types: control mix, rubberized mix, warm rubberized mix 1 and warm rubberized mix 2 * 4 compaction temperatures: 97, 116, 135, and 154°C * 6 repetitions) were fabricated using Superpave gyratory compactor. Volumetric properties of the specimens were evaluated. The results showed that the warm mix processes were effective to improve the volumetric properties of rubberized mixes at a certain range of compaction temperatures.