As the demand for eco-friendly infrastructure grows, the road construction industry is adopting innovative methods to reduce emissions and embodied carbon in materials, addressing the global push towards sustainable development and setting a path for a more resource-efficient future in infrastructure. Embodied and operational carbon in the cement sector “While operational carbon – emissions during usage – gets much attention, embodied carbon, which accounts for emissions during construction, represents a significant portion, especially in highways where 50-60 per cent of carbon is embodied,” said Monika Shrivastava, Head of Sustainability, JSW Cement, highlighting the importance of addressing both embodied and operational carbon footprints in road and infrastructure projects. She noted that using ground granulated blast furnace slag (GGBS) as an eco-friendly alternative to ordinary Portland cement (OPC) reduces carbon emissions from 740 kg per tonne (OPC) to 80 kg per tonne, significantly lowering the environmental impact. As cement manufacturing emits significant amounts of CO2, around 20 per cent of the company’s energy is sourced from renewables, including solar power. It aims to increase this from 20 to 60 per cent by 2030, aligned with its broader sustainability goals. Use of eco-friendly materials “In many of our road projects, we’ve implemented pavement quality concrete (PQC) and residual pavement methods with cement content limited to 450 kg per cu m,” said Satyanarayan Purohit, Vice President, Dilip Buildcon, emphasising the company’s commitment to sustainable construction practices. As a case in point, he highlighted the use of GGBS in the construction of the Zuari Bridge in Goa, where about 90,000 metric tonne of GGBS was utilised, reducing carbon emissions by around 40,000 tonne. As for use of recycled plastic in road construction, he noted that sourcing remains an issue. Waste to wealth “In infrastructure development, the focus must be on the three Rs: reduce, reuse and recycle,” said Dr Satish Pandey, Principal Scientist, Central Road Research Institute (CRRI). “India has the second-largest road network globally, which consumes about 1.2 billion tonne of natural aggregates annually for construction and maintenance.” To tackle this growing shortage of aggregates, CRRI has developed steel slag road technology, which repurposes waste steel slag as a substitute for natural aggregates. India produces around 20 million tonne (mt) of steel slag annually, a figure that is expected to triple by 2030. Steel and CO2 footprint “Steel is the backbone of infrastructure and its production has both challenges and opportunities, especially as global standards push for reduced carbon emissions,” said Neeraj Kant Jha, AVP - Sales and Marketing, MS Agarwal, emphasising the critical role of the steel industry in infrastructure development and sustainable highway construction. “Our commitment to delivering greener steel aligns with the increasing demand from customers for environment-friendly products,” he added about the sector’s adoption of electric arc furnaces (EAFs). As the Indian steel sector is set to undergo a major transformation, with the Ministry of Steel targeting net-zero emissions by 2070, requiring an investment of around $ 230-240 billion, Jha highlighted the need for innovative energy sources, such as hydrogen, to replace traditional coal-based processes. Materials, machinery and skilled workforce “Machinery alone cannot construct roads; it is the trained workforce that ensures quality and sustainability. If any link in this chain is weak – be it subpar manpower or machinery – the goal of achieving sustainable infrastructure will falter,” cautioned Prof Dharamveer Singh, Department of Civil Engineering, IIT Bombay. He pointed out that despite access to world-class machinery and materials, he had witnessed numerous road failures within just two years of construction owing to inadequate training and quality control. He also suggested adoption of innovative technologies to improve road longevity and reduce reliance on natural aggregates. The green way ahead The panel discussion focused on sustainable construction innovations in various sectors concluding with a call to action in terms of continued innovation and adoption of sustainable practices.