Sripath Technologies President Krishna Srinivasan was recently honored to speak to a delegation from the Government of Goa, India’s Public Works Department (Roads) during a conference coordinated by Bitpath, a Sripath affiliate based in India. The presentation topic, “Innovative Additives to Enhance Roadway Performance,” reflected the growing need for solutions to using high-RAP mixes on Indian roadways to address interest in lowering costs, leveraging recycled materials, and improving performance for rutting, cracking, and other physical characteristics. This is especially relevant as Indian roadway construction continues to accelerate among one of the largest road networks in the world.
Srinivasan provided an in-depth review of the practical benefits of utilizing high-RAP mixes, or those with more than 25% reclaimed asphalt pavement material. This includes material cost reductions, long-term performance improvements, and environmental advantages. Srinivasan also explained the protocol for RAP utilization such as the need to treat RAP as a valuable source material, mix design requirements, and how to incorporate RAP into a mix plant.
Importantly, to achieve long-lasting and high-performing mixes comprised of high amounts of RAP, mix engineers need to incorporate an asphalt rejuvenator. Srinivasan explored the role of balanced mix design and dosing mixes with an effective rejuvenator in order to balance properties such as rutting resistance and fracture toughness. While aggregates do not change with age, the binder or bitumen in the mix oxidizes and changes over time. Adding an asphalt rejuvenator can restore the functional properties of the aged bitumen in the mix, enabling mix engineers to use high amounts of RAP without compromising roadways performance.
Srinivasan also presented laboratory and field trial data regarding Sripath’s ReLIXER®, an effective asphalt rejuvenator, including Ideal CT results, durability profiles, and aging data as compared to control mixes and those using traditional petro oil rejuvenators. The results demonstrate that ReLIXER provides equivalent performance compared to low-RAP and no-RAP mixes and superior results compared to petrochemical rejuvenators. ReLIXER also offers low dosing requirements, potential cost savings, and environmental benefits.
For roadway repair and maintenance projects, ReLIXER can also be coupled with PGXpand®, a bitumen-friendly polymeric additive, to improve high temperature properties in the mix without impacting low temperature properties. The result can be long-term performance and durability with easy-to-implement, high-RAP pothole and patch mixes.
Srinivasan, Bitpath, and the entire Sripath team appreciate the participation of the delegation from the Government of Goa Public Works Department (Roads) and look forward to additional opportunities to gather and collaborate.
