In a groundbreaking study published in the *Journal of Road Engineering* (translated from Persian as *Magazine of Road Engineering*), researchers have uncovered a promising avenue for sustainable road construction by repurposing industrial byproducts. The research, led by Shiva Kumar Govindaraju from the Department of Civil Engineering at Dayananda Sagar College of Engineering in Bangalore, India, explores the integration of electric arc furnace (EAF) slag and waste plastic into stone matrix asphalt (SMA) mixtures. This innovative approach not only addresses environmental concerns but also offers substantial commercial benefits for the energy and construction sectors.
With over 70 million tons of EAF slag and 300 million tons of plastic waste generated annually worldwide, the potential for large-scale recycling is immense. “The idea was to transform these waste materials into valuable resources for road construction,” Govindaraju explained. “By doing so, we can reduce landfill waste, lower production costs, and enhance the performance of asphalt mixtures.”
The study evaluated various SMA mixtures, replacing conventional aggregates with EAF slag and modifying the binder with waste plastic. The results were promising. The addition of waste plastic, ranging from 4% to 12% by weight of bitumen, significantly improved key properties such as rutting resistance, fatigue life, and stiffness. “The optimal waste plastic content was found to be 8% by weight of bitumen,” Govindaraju noted. “This level provided the best balance of performance and sustainability.”
EAF slag mixtures demonstrated superior drain-down characteristics and moisture susceptibility compared to conventional aggregates. The ultrasonic pulse velocity tests further revealed higher stiffness in the modified mixtures, indicating enhanced durability and longevity. “These findings suggest that incorporating EAF slag and waste plastic into SMA mixtures can lead to high-performance road construction solutions,” Govindaraju added.
The commercial implications of this research are far-reaching. For the energy sector, the use of waste plastic as a binder modifier could reduce the demand for virgin bitumen, lowering production costs and environmental impact. For the construction industry, the integration of EAF slag as an aggregate replacement offers a cost-effective and sustainable alternative to traditional materials.
As the world grapples with the challenges of waste management and sustainability, this research provides a viable pathway for repurposing industrial byproducts. The findings not only highlight the potential for high-performance road construction but also pave the way for future developments in sustainable infrastructure. With further research and implementation, this innovative approach could revolutionize the construction industry, offering a greener and more efficient future for all.