Researchers from the U.K.’s Materials Processing Institute (MPI) are exploring the use of steel-making slag waste in the construction of roadways in the U.K.

In a bid to keep steel-making slag — which is a byproduct of steel-making wherein impurities are separated from molten steel in steel-making furnaces — from being landfilled, the team from MPI is exploring avenues for repurposing the slag as roadway aggregate.

To improve its performance as a roadway aggregate, the MPI team intends to increase the silica content of the slag, thereby improving the quality and consistency of the slag, and thus its suitability for roadways.

Tarmac, British Steel, Glass Futures Ltd and PWS road building services are among those who are taking part in the project alongside MPI. Together, the companies will explore repurposing slag from other steel-making efforts such as desulphurisation slag. Tarmac will test the skid resistance of each iteration of slag-aggregate and the best performing material will be trialed.

Each year, thousands of tonnes of steelmaking slag is produced in the U.K. alone, much of which cannot be disposed of.