Performance Study of Polymer Modified Asphalt for Durable Pavements

The rapid growth in traffic volume coupled with wide climatic variations in India has intensified the demand for durable and high-performance pavement materials. Conventional VG-40 bitumen often exhibits premature distress, such as rutting and fatigue cracking, under high temperatures and heavy traffic loading. This study presents a comparative performance evaluation of Polymer Modified Bitumen (PMB RG 70-10E) and VG-40 binder used in Bituminous Concrete (BC-2) mixes, in accordance with MoRTH (5th Revision, 2013) specifications. A comprehensive laboratory investigation was conducted, including Marshall Stability and Flow, Indirect Tensile Strength (ITS), Resilient Modulus, and Dynamic Creep tests, to assess the mechanical behavior and durability of the mixes. The Optimum Bitumen Content was determined as 5.4% for VG-40 and 5.6% for PMB RG 70-10E. Experimental results demonstrate that PMB-modified mixes achieved approximately 18.4% higher Marshall stability, 35% improvement in ITS, and 54% increase in resilient modulus compared to VG-40 mixes, along with substantially lower permanent deformation under repeated loading. The improved performance is attributed to the enhanced elastic recovery, cohesive strength, and binder–aggregate bonding characteristics of PMB, which contribute to improved fatigue resistance and reduced temperature susceptibility. Overall, the findings confirm that PMB RG 70-10E offers superior strength, durability, and deformation resistance, making it a viable and effective binder for long-life and heavy-duty flexible pavements under Indian traffic and climatic conditions.