Use of a Premium SBS ModifiedBitumen to Combat Severe Rutting in Asphalt Pavement

Severe rutting occurred in a section of National Highway Project A within six weeks of opening to traffic with rut depths observed as deep as 15 cm. The cause of the rutting has been investigated and analyzed and a new binder and asphalt mix specification were proposed to satisfy the requirements for both the heavy traffic and climatic conditions. The rut resistance and water sensitivity of the binder and failed asphalt mix were evaluated first in the laboratory. Specific requirements for a higher performance binder and mix were then proposed and incorporated in the road reconstruction project. This was followed by performance monitoring of the new pavement. The conclusions from the case study are detailed in the paper.