The Border Road Organisation (BRO) is planning to construct a pilot road stretch in Arunachal Pradesh using steel slag, which can withstand heavy rains and adverse climatic conditions. Creating durable roads along strategic areas could become easier if this project gets successful.
This is a new project for BRO but earlier, a six-lane highway made by using 100 per cent processed steel slag was inaugurated in Surat, Gujarat in June this year.
The approximate construction cost per square metre of a processed steel slag road is Rs 1,150 as against Rs 1,300 for a bitumen road and Rs 2,700 for cement or a concrete one. The lifespan of a cement or concrete road is over 30 years while that of bitumen and steel slag road is around 15 years.
What is Steel Slag?
Steel slag is an industrial byproduct obtained from the steel manufacturing industry. It is produced in large quantities during steel-making operations that use electric arc furnaces. Steel slag can also be produced by smelting iron ore in a basic oxygen furnace.
The road constructed by 100 per cent use of steel processed slag not only increases the durability but also help in reducing the cost of construction as slag-based materials are having better properties than natural aggregates.
The Indian Road Congress (IRC) guideline stipulates that for construction of a heavy traffic road, 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).
The National Highways Authority India (NHAI) will also use the steel slag for construction of a portion on Mumbai-Goa highway and the Indian Railways has also sanctioned a major research and development (R&D) project to Council of Scientific and Industrial Research (CSIR) and Central Road Research Institute (CRRI) to explore possible utilisation of steel slag aggregate as railway ballast for track construction and maintenance.
The Surat airport is also going to strengthen its airstrip using steel slag as per the International Civil Aviation Organisation (ICAO) recommendations and civil aviation requirements (CAR), according to airport authorities.
Important Points related to Surat Project
The one-kilometre road in Hazira, Surat has been built as part of a R&D project of the Union Ministry of Steel in collaboration with the CSIR and CRRI — a laboratory of CSIR and the government think-tank NITI Aayog.
It has been built by ArcelorMittal-Nippon Steel India (AM-NS), a leading steel manufacturer. Steel maker AM/NS India said the six-lane road was constructed using around 1 lakh tonnes of processed steel slag from its manufacturing plant in Hazira.
The project was developed with the aim to convert “waste to wealth” and has entered the India Book of Records and Asia Book of Records.