Gwangyang Steelworks Recycles Steel Slag as Road Pavement Material

Twice the Lifespan Compared to Conventional Aggregate
Reduces Fine Dust and Noise

POSCO Gwangyang Steelworks (headed by Ko Jaeyoon) has taken a proactive role in realizing a circular economy by using steelmaking slag as aggregate for asphalt paving within the steelworks.

Various by-products such as slag and sludge are generated during the steel production process. Among them, steelmaking slag (hereafter referred to as slag) is produced during the steelmaking process, where it serves to remove impurities from molten iron.

Gwangyang Steelworks is paving roads within the steelworks using asphalt concrete made with steelmaking slag as aggregate. Photo by Gwangyang Steelworks

Until now, slag had only been used for limited purposes such as construction sites or road foundations. However, due to its density being over 37% higher than natural aggregate, its excellent durability, and its regular surface structure that provides strong resistance to deformation and good interlocking, slag has recently begun to attract attention as an aggregate for asphalt concrete (hereafter referred to as asphalt concrete).

In particular, when slag is used as aggregate for asphalt concrete, the lifespan of the road can increase up to twice compared to regular asphalt concrete, the amount of fine dust generated is reduced by half, and vehicle noise can be decreased by up to 9.3 dB, among other advantages.

To actively utilize these benefits of slag, POSCO began supplying slag to asphalt concrete companies in June last year, applying it for the first time in the paving of the Chungju section of National Road No. 3. On the 14th, POSCO also applied slag-based asphalt concrete to roads within the steelworks itself, planning to expand its use after comparing its performance with the previously used asphalt concrete.

Gwangyang Steelworks expects not only to improve road maintenance cycles but also to contribute to the conservation of natural resources by replacing natural aggregates with slag.

A Gwangyang Steelworks official stated, "Slag asphalt concrete is an efficient recycling method for steel by-products," and added, "We will continue to actively utilize steel by-products and establish resource circulation measures that can simultaneously create environmental and economic value."