In line with Centre’s ‘Waste to Wealth’ mission and encouraging environmentally sustainable National Highways construction, trial use of ‘Steel Slag’ in road construction has been initiated by central road making agency NHAI. This initiative will help to address challenge of shortage of material used in development of the National Highways, and could replace natural aggregates such as sand, gravel, or crushed stone with the waste material from the steel industry.  

To construct India’s first Pavement Quality Concrete (PQC) with steel slag, The National Highways Authority of India (NHAI) started trials for its possible use in road construction. The authority permitted Central Road Research Institute (CRRI) to construct one km long trial patch in Raigarh district for PQC of Panvel – Indapur section of NH 66 near Mumbai where 100% natural aggregates were replaced by steel slag derived aggregates. The results from the trial have been encouraging.

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 the new addition to the several innovative resources like old tyres, garbage, plastic, construction and demolition debris, glass, shingles et used in construction activities of roads, highways.

A senior Road Transport Ministry official said NHAI has been encouraging the innovative use of new alternative material like use of plastic waste, building & construction waste etc. and the road constructed by use of steel slag is an example of converting waste into wealth. “Use of such material in road construction shall make construction more economical and will promote circular economy and resource efficiency.

The NHAI has already been using garbage as recycled materials which is also way to limit waste production. “By recycling waste materials, we can limit resource extraction, reduce our environmental impact, and avoid overfilling landfills.

With ever growing population there are more cars on the roads and as we need to construct and repair more highways we shall need resources at a affordable cost,” added the official.