Feasibility of Superpave gyratory compaction of rubberized asphalt concrete mixtures containing reclaimed asphalt pavement

Recently, some specific materials such as ground crumb rubber are widely being used to save money (e.g. longer life) and protect the environment. In addition, the utilization of reclaimed asphalt pavement (RAP) is an acceptable practice in many states. However, the use of these materials in the Superpave mix design system is not standardized, so it is essential to investigate whether a rubberized asphalt concrete (RAC) mixture containing RAP can be used in the Superpave mix design procedure. In general, the use of RAP in the past has proven to be economical, environmentally sound, and effective for enhancing the engineering properties of asphalt mixtures. Crumb rubber has also been used successfully in improving the mechanical characteristics of an HMA mixture. The objective of this research was to investigate the feasibility of the Superpave mix design of rubberized asphalt mixtures containing RAP through volumetric analysis of various mixtures with respect to crumb rubber type, percentage and RAP percentage in the mixture. The results of this limited study indicated that increasing the rubber content led to an increase of the optimum binder content; the two rubber types had good workability with virgin and RAP mixtures; and the Superpave mix design method and volumetric analysis can be used for the rubberized asphalt mixtures containing RAP.

► This study investigated Superpave mix designof rubberized mixture containing RAP.
► Results found that increasing rubber content led to an increase of binder content.
► Two rubber types had good workability with virgin and RAP mixtures.
► Volumetric analysis can be used for rubberized asphalt mixtures containing RAP.