NHAI releases first sustainability report on environmental responsibility
Recently the National Highways Authority of India (NHAI) has released its first Sustainability Report for the financial year 2021-22.
The sustainability report covers NHAI’s governance structure, its stakeholders, environment and social responsibility initiatives.
Keep findings of Report:
- The greenhouse gas emission intensity of NHAI has registered a sequential reduction of 9.7% in FY 2020-21 and 2% in FY 2021-22.
- NHAI is using recycled materials for construction of highways. These include recycled asphalt and recycled aggregates.
- Recycled asphalt is a reprocessed material used in road construction. These include asphalt and other auxiliary materials.
- Recycled concrete aggregates (RCA) are produced by crushing demolished concrete elements. RCA differ from fresh aggregates due to the cement paste attached to the surface of the original natural aggregates after the process of recycling. This highly porous cement paste and other contaminations contribute to the lower particle density and higher porosity, variation in the quality of the RCA and the higher water absorption.
- NHAI has increased the use of certain materials in road construction to ensure sustainability and reduce greenhouse gas and carbon emissions.
These include the following –
- Fly ash, which is a by-product from the combustion of coal;
- Plastic waste in a hot bituminous mixture;
- Steel slag, which is a by-product from the manufacture of steel;
- Inert materials obtained from landfill sites that are neither chemically nor biologically reactive;
- Geo-synthetic materials like coir/jute;
- Cold asphalt mixes, which are unheated mineral materials. These are made either by mixing with bitumen or foamed bitumen;
- Copper slag, which is a by-product of copper smelting.
National Highways Authority of India (NHAI)
- NHAI was established under the NHAI Act, 1988. This organization is responsible for the development, maintenance and management of National Highways across India.
- It is a nodal agency of the Ministry of Road Transport and Highways (MoRTH). It is entrusted with the task of implementation of National Highway Development Projects.
Steel Slag-
- Steel slag is produced in steelmaking furnaces in the process of separating molten steel from residual impurities.
- Asphalt content also includes steel slag. It is a by-product obtained from steel and iron production processes.
- It can be used in a number of activities, such as in construction and road (levelling), in agriculture (due to its ability to reduce soil acidity), in the manufacture of Portland slag cement, etc.
Source – PIB
