Investigating the rheological properties of rubberized-bitumen blends modified with warm mix additives

Abstract. Crumb rubber modified asphalt (CRMA) can significantly contribute to environmental sustainability by reusing recycled tire crumbs as well as extending the service life of asphalt pavement. Ground Tire Rubber (GTR) has been successfully utilized in Kuwait as an additive in Hot Mix Asphalt (HMA) with a percentage of 12.5% of the binder weight. In the present work, the aim is to increase the GTR content to 17.5% of the binder weight to achieve maximum environmental benefit. This presents a significant challenge during the construction of the pavement, as incorporating a high content of GTR in asphalt binder considerably increases the viscosity of the asphalt, hence adversely affecting its workability. Therefore, the main objective of this study is to investigate the effectiveness of using “Viscobit” polymers to improve the rheological properties of the rubber-bitumen blend. This study made significant contributions to the advancement of research on rubberized asphalt conducted by Kuwait Institute for Scientific Research team. Conclusions and recommendations for future work are included in this paper.