Traditional methods and materials for roadway development may be here to stay, but the advent of sustainably produced additives that may support contractor and department of transportation goals to lower their carbon emissions are much newer to the industry. Newer still is the perspective that asphalt and bitumen additives can be produced with a lower carbon footprint, helping contribute to a lower Global Warming Potential (GWP) from the start. This perspective was explored in an article published in the Fall 2024 issue of AsphalTopics cowritten by Sripath Technologies President Dr. Krishna Srinivasan, Senior Technical Director Vince Aurilio, and Chief Operating Officer Dr. Deepak Madan.
Cradle to gate analysis considers the environmental impact of raw materials, raw material transport, product manufacturing, and product transportation. Paired with carbon sequestration analysis, which considers the amount of carbon dioxide captured within product materials, these perspectives can provide key insights into the carbon footprint of additives used in roadway development. This understanding is proving important as agencies are increasingly focused on lowering their overall GWP including the products they use.
Sripath is unique in that it provides transparent and public access to its sustainability data through independently verified Environmental Product Declarations (EPDs) and Sustainability Reports. These documents provide detailed information that can be used to help customers achieve their carbon emission goals. EPDs are currently available for ReLIXER®, an asphalt rejuvenator, PGXpand®, a bitumen-friendly polymeric additive, and NuMIXER®, a bitumen softener.
Each Sripath additive is designed with sustainability in asphalt or bitumen use in mind. ReLIXER not only enables contractors to use higher amounts of reclaimed asphalt pavement (RAP) in their mixes but also exhibits a GWP of -1.677 as a bio-based oil blend. PGXpand, which enhances high-temperature performance while retaining low temperature mix properties, was determined to have a GWP of 3.270, which is ecofriendly compared to other available additives. Notably, PGXpand also helps contractors lower their overall energy consumption by allowing for lower shear mixers, shorter blending times, and lower blending temperatures. A green bio-oil based softener, NuMIXER achieves a GWP of -1.597, typically more environmentally friendly than traditional petrochemical softeners, while helping manage bitumen viscosity, improving low temperature properties, and improving fracture toughness and fatigue resistance.
Importantly, each Sripath product is also rigorously tested by independent researchers to assess the performance capabilities of each additive. The results, outlined in detail in this article, demonstrate that Sripath’s portfolio not only supports sustainability in asphalt projects but also provides desired performance outcomes backed by proven data.
Read the full article for an in-depth look at how Sripath’s products encourage sustainability in asphalt, supporting contractor demand for high performing additives that can contribute to a lower carbon footprint.
