Researcher Seeks to Create Cleaner Asphalt

Ali Behnood is among 38 recipients nationwide to receive support for their work to create sustainable, greenhouse gas-reducing construction materials. Behnood, assistant professor of civil engineering at Ole Miss, received $750,000 for his project.

"As stewards of the future, we are committed to advancing towards more sustainable and resilient infrastructure to uphold our responsibility to the next generation," Behnood said. "Our efforts are focused on developing systems that not only meet today's needs but also ensure environmental integrity and durability for the future.

"This shift is crucial in mitigating the impacts of climate change and providing a stable foundation for the generations to come."

The wide-ranging use of asphalt means Behnood's project could have a broad effect on American construction material manufacturing, said Viola Acoff, dean of the School of Engineering.

"Dr. Behnood's work has the potential to develop an asphalt that is not only environmentally friendly, but also has better mechanical properties and is more cost-effective than traditional asphalt," Acoff said. "His work can lead to the University of Mississippi becoming a leader in this field of research."

Construction materials used in buildings, roads and other infrastructure account for more than 15% of annual greenhouse gas emissions in the U.S. and 37% worldwide.

"The construction industry bears a significant responsibility to address its impact on climate change," Behnood said. "We are actively seeking effective approaches to reduce our contribution to this global issue."

In asphalt production, most greenhouse gas emissions come from heating asphalt's binder to 280-320 degrees, which requires a lot of energy. Behnood is helping test the quality and durability of warm-mix asphalt, a mixture of reclaimed asphalt and a new binder that cuts the required heat by up to 60 degrees.

"By lowering the mixing and compaction temperatures in asphalt production, we significantly reduce the need for additional energy," he said. "This reduction not only decreases greenhouse gas emissions but also leads to substantial cost savings."

The unknown is how well warm-mix asphalt compares to its traditional counterpart and what additives make the material most effective and environmentally friendly.

"We are embarking on a comprehensive evaluation of a diverse range of additives to determine their potential benefits in asphalt production," Behnood said. "Our study will focus on comparing these additives to assess their ability to save energy, reduce greenhouse gas emissions and enhance the mechanical properties of asphalt.

"This research aims to identify the most effective additives that not only contribute to environmental sustainability but also improve the quality and durability of asphalt pavements."

To study each of these variables, Behnood plans to use artificial intelligence and machine learning to test predictive models of warm-mix asphalt.

"Construction is an essential activity that continues as development progresses, and it plays a crucial role in accommodating the growing needs of our society and economy," he said. "That is the demand, but it necessitates a more responsible approach to development. We must ensure that our growth strategies are sustainable and considerate of environmental impacts.

"We can no longer justify contributing to greenhouse gas emissions without restraint. It is imperative that we adopt more responsible and sustainable practices in our activities to mitigate environmental impact."

This material is based on work supported by the Environmental Protection Agency's Reducing Embodied Greenhouse Gas Emissions for Construction Materials and Products program.

Top: The manufacture of asphalt, commonly used in roads, parking lots and other infrastructure, produces greenhouse gasses, which contribute to climate change. Ali Behnood, assistant professor of civil engineering, is using funding from the Environmental Protection Agency to study ways to make asphalt more environmentally friendly. Photo by Robert Jordan/Ole Miss Digital Imaging Services