November 4, 2025
Sustainable Infrastructure Construction Using Basic Oxygen Furnace Slag
Project 1.2.5 “Transport infrastructure construction using steel furnace slag” aims to achieve clear industry and environmental-focused outcomes through increasing the use of a steelmaking by-product, basic oxygen furnace slag (BOFS), to create composite materials for transport infrastructure construction.
In a very collaborative effort between a ÁñÁ«ÊÓƵapp of ÁñÁ«ÊÓƵapp (UOW) research team, including , Dr Pabasara Wanniarachchige, and PhD candidate Yeshwanth Sunkara, along with their industry partner, Mark Micallef, Benjamin Muscat and Ferit Uyguc from Australian Steel Mill Services This project was the first to be launched under the Steel Research Hub’s Small and Medium Enterprises (SME) Engagement & Innovation Program. ASMS is a local company contracted by to collect and process molten slag from the ironmaking blast furnace and steelmaking processes. The SME processes approximately 1.2 million tonnes of slag annually.
BOFS has traditionally been stored in large stockpiles. It presents challenges because it swells when exposed to water. This swelling can cause the ground to lift or crack, making it risky to use in roads or building foundations. As a result, BOFS has long been considered unsuitable for construction and often left unused.
Recent research at UOW has shown that combining BOFS with another steel by-product known as granulated blast furnace slag (GBFS) can reduce the swelling or expansion associated with BOFS. When BOFS and GBFS are combined in the right proportions, the resulting material can perform just as well and sometimes even better than traditional construction materials. Laboratory tests have demonstrated that these mixtures are not only stable but also able to support significant loads. In fact, the shear strength and stiffness of the BOFS–GBFS blends are often comparable to, or even exceed, those of traditional road base materials like crushed rock or gravel. This means that, when carefully prepared, recycled slag can provide the same level of durability required for heavy traffic loads, while using far fewer natural resources.
“ is proud to collaborate with UOW on cutting-edge research that transforms steelmaking by-products into high-value, sustainable materials. The findings that combining BOFS with GBFS significantly reduces swelling opens new pathways for safer, more reliable applications in civil construction and infrastructure. For our clients, this means access to engineered materials with improved performance and environmental credentials ultimately leading to lower net emission in infrastructure construction”.