Surat has become the first city in the country to get a processed steel slag (industrial waste) road built as part of a joint-venture project by the Council of Scientific and Industrial Research (CSIR), Central Road Research Institute (CRRI), Union Ministry of Steel, government think-tank NITI Ayog, and ArcelorMtttal-Nippon Steel (AM/NS), at Hazira.
What is the project all about?
- The six-lane public road is a kilometre-long stretch in Hazira industries, which also houses the AM/NS plant.
- The construction began around a year ago by converting mounds of steel waste into steel slag aggregate.
- The sixth and final lane of the road, with a three-lane to-and-fro carriageway on either side, was completed in early March.
- The road is now being used by heavy-duty vehicles of multinationals located in the industrial estate on the outskirts of Surat.
- The construction cost of the processed steel slag road is 30 per cent cheaper than roads built from natural aggregates. The Hazira road uses around 1 lakh tons of processed steel slag.
How is it made?
The slag is generated from a steel furnace burning at around 1,500-1,600 degree centigrade in the form of molten flux material as an impurity. The molten material is poured into the slag pits for cooling as per the customised procedure and further processed to develop stable steel slag aggregates, with “better material properties in place of the natural aggregate commonly used in road constructions”.
How is it better over other roads?
- According to the Indian Road Congress guidelines for construction of a heavy traffic road that is capable of taking the load of 1,000 to 1,200 trucks per day, around 600 to 700 mm thickness of road layers are required on the foundation with 8 per cent CBR (California Bearing Ratio). In comparison to normal highways, the ones made out of steel slag are 30 per cent less thick because of better material characteristics.
- The utilisation of processed steel slag in road construction paves the way for sustainable use of waste and reduces the reliance on perishable natural aggregates. This process is also expected to reduce GHG emissions and carbon footprint in road construction activity