Road Surface Technologies Issue Highlights PGXpand’s Role in Reducing Carbon Emissions

The global asphalt industry remains under the growing urgency to reduce greenhouse gas (GHG) emissions and support a circular economy. As producers work toward net-zero goals, one key area of focus is the improvement of polymer modified bitumen (PMB), which has remained a cornerstone of durable, high-performance pavements for decades. 

In a recent feature published in Road Surface Technology 2025, Sripath Technologies shared how its bitumen-friendly polymeric additive PGXpand® is helping contractors and agencies lower their carbon footprint while maintaining the performance standards expected of PMB. 

The Sustainability Advantage of PMB 

PMB is widely used in road construction for its ability to enhance resistance to rutting, cracking, and aging. The result can be longer-lasting roads that require fewer repairs, saving both materials and energy. However, traditional PMBs can be energy intensive to produce and can carry a higher global warming potential (GWP). 

PGXpand: A Bitumen-Friendly Polymeric Additive 

Sripath's PGXpand is engineered to deliver the high-performance characteristics needed in PMBs while helping reduce carbon emissions. The additive blends easily into bitumen using low shear mixing equipment, shorter mixing times, and lower temperatures, all of which can result in reduced energy consumption and production costs. 

The Environmental Product Declaration (EPD) for PGXpand documents the product's GWP of 2.95 kg CO₂eq per kg, compared to roughly 4.5 kg CO₂eq per kg for typical polymers used in PMB production. Studies show that replacing SBS with PGXpand can reduce GWP by up to 85% without compromising rutting resistance, fatigue performance, or workability. 

PGXpand's unique formulation also reduces the need for crosslinking or warm mix additives to help further minimize raw material use and overall emissions. Mixes containing PGXpand can also be manufactured and compacted at significantly lower temperatures compared to traditional PMBs. Its versatility allows it to be used in a range of PMB applications including hot mix, hybrid PMBs, spray seals, and maintenance treatments. 

Sustainable Asphalt in Practice 

A variety of field and laboratory trials over the past decade have demonstrated PGXpand's benefits firsthand. In just one example, a one-kilometre, four-lane roadway paved with a PGXpand-dosed polymer modified bitumen achieved excellent workability and rutting resistance at a paving temperature 30°C lower than the control mix. 

With its focus on innovation, transparency, and performance, Sripath continues to lead in the development of sustainable asphalt additives that make polymer modified bitumen production cleaner, more efficient, and better for the planet. 

Read the complete article in Road Surface Technology 2025.