'Eco-Steel Asphalt Concrete' Utilizing Steelmaking By-products Contributes to Road Durability and Fine Dust Reduction

Asphalt concrete using steel slag is characterized by much higher strength and less wear compared to general natural aggregate asphalt pavement. In general asphalt pavement, aggregates easily break due to impact from vehicle traffic, generating fine dust, but steel slag aggregates hardly break, significantly reducing the amount of fine dust generated. An official stated that as a result of conducting tests in a sealed space, the amount of fine dust generated was confirmed to have decreased by 87%.

As a result of comparative construction of general asphalt concrete and eco-steel asphalt concrete on Incheon's Gyeongwon-daero, a clear difference between the two materials was observed even after 8-9 years. While the general asphalt concrete section showed signs of aging with numerous cracks over time, the eco-steel asphalt concrete section remained clean and looked like new, even to the naked eye. The presenter mentioned that this allowed them to directly observe the excellent durability of eco-steel asphalt concrete.

The development of Eco-steel asphalt concrete began with the difficulty of securing aggregates due to restrictions on quarry development in the Seoul metropolitan area. An official explained that the research started with the idea of applying high-quality slag, which steel companies were using as sub-base or fill aggregates for roads at the time, to road surface layers as well. Subsequently, the method of using slag, a steel by-product, for road surface layers was concretized, and the optimal mixing ratio was developed, leading to the registration of new construction technology and the birth of the current Eco-steel asphalt concrete.

Quality tests of eco-steel asphalt concrete were conducted in Ukraine under extreme climatic conditions. Technical discussions were held at the request of the chairman of a Ukrainian iron ore company, and a test pavement of general asphalt concrete and eco-steel asphalt concrete was installed last September. After enduring a severe winter with temperatures dropping to -20 degrees Celsius, the quality verification results in April were surprising. While the general asphalt concrete section experienced severe road cracking and fatigue, the eco-steel asphalt concrete section remained almost as clean as when it was installed, proving its excellent durability in extreme environments. An official emphasized that this eco-steel asphalt concrete technology could simultaneously solve Ukraine's serious aggregate supply problem.

Indonesia faces severe aggregate supply shortages and high asphalt concrete prices due to environmental crises caused by rising sea levels and restrictions on natural aggregate extraction. In this situation, eco-steel asphalt concrete technology is receiving great interest from the Indonesian government. Currently, POSCO International and SG have established a joint venture and are promoting a new toll road project of approximately 1,000km with the local state-owned company 'PT Hutama Karya'. This project is a large-scale project with an estimated total cost of 8.4 trillion Korean Won.