The National Highways Authority of India (NHAI), a central government agency mandated to construct highways across the country has undertaken trial projects to use steel slag replacing natural aggregates like sand, gravel or crushed stones in construction, a statement of the agency said on Thursday, March 16.
The NHAI had mandated the Central Road Research Institute (CRRI) to undertake a pilot project for the construction of a 1 km stretch of highway using steel slag, the results of which “have been extremely encouraging”, the statement said.
Slag contains a range of refined metal materials, including copper, steel, and aluminium. Given the durability of slag, it prevents highways from breaking or changing shape over time. Slag also prevents corrosion. This is a new addition to several innovative resources like old tyres, garbage, plastic, construction and demolition debris, glass and shingles used in the construction activities of roads and highways, the NHAI said.
It said that more projects for highway construction will be undertaken using steel slag as aggregate, replacing natural materials, as it is not only cost-effective but also promotes the circular economy for steel mills.