Life Cycle Assessment of Highway Construction Projects in India—A Case Study of National Highway 66

The worldwide issue of greenhouse gas (GHG) emissions is urgent because they have a considerable impact on climate change and threaten both natural and human ecosystems. The demand for highway projects is rising in India as urbanization continues to soar, and if not managed responsibly, might worsen pollution and GHG emissions. Life cycle assessment (LCA) technique can be used to measure the GHG emissions in a project. However, the prospects of analyzing GHG emissions in highway projects are little explored in India. The present study analyzed the GHG emissions in the construction phase of the six laning of National Highway-66 in Kerala, India. The GHG emissions in the construction phase and its impact on global warming were analyzed based on sources like material production, on site transportation, to site transportation using openLCA 2.0.1 software. It was found that material production phase had more GHG emissions compared to the transportation phase. The production of Portland cement showed highest emission compared to other materials which was followed by steel and gravel. A sensitivity analysis was carried out to explore the GHG emissions in the case where materials like cement and natural aggregates were replaced by sustainable materials like fly ash (FA) and recycled coarse aggregates (RCA), respectively. Results indicated that 28.5% reduction in the emissions were observed when Ordinary Portland Cement (OPC) was replaced by 50% FA and it could reduce the global impact by 28.3%. Also, replacement of 100% RCA reduced the emissions by 6.8% and subsequently, global warming impact by 7.05%. These results underline the importance of sustainable construction practices and its implementation by ensuring proper policy and regulatory interventions.