Pavement sustainability has been accorded the utmost importance in recent times. However, the construction industry has faced a number of issues related to the adoption of new and innovative materials and techniques. At a recent conference organised by India Infrastructure on Green Roads for India, key government and industry stakeholders discussed the roadblocks to technology infusion and recommended initiatives to be taken to address this. Discussed below are the key takeaways from two panel discussions held at the event. The first panel, comprising Saurabh Bhargava, deputy manager, ICT; Deepak Jotawar, principal manager, STUP Consultants; Shankar Lohani, associate director, AECOM India and Sunil Sapru, chief executive officer, marketing, Ammann India, focused on the trends in design and material requirements for flexible pavements and the cost effectiveness of different kinds of pavements. The second panel, comprising Neha Mishra, senior environmental specialist, World Bank; Manoj Kumar, chief general manager, National Highways Authority of India; Atasi Das, senior general manager, design, GR Infraprojects; Dr Sunil Bose, consultant; Dr Oroz Gonzalo, product manager, CFF GmbH & Co.; and Dr N.S. Raman, general manager, Indian Oil Corporation Limited, highlighted the key initiatives to reduce the environmental impact of asphalt pavements and the potential for bitumen recycling. Excerpts…
A variety of new techniques and materials have emerged recently for flexible pavements, including the use of materials such as waste plastic as a substitute for aggregates. In fact, codes defined by the Indian Roads Congress (IRC) have evolved over time to meet the changing construction needs and the growing focus on environment-friendly methods of road construction. However, adapting to the latest technologies remains a challenge.
Players in the road sector are familiar with the use of conventional technologies and face difficulties in adopting the latest ones. Hence, the government should focus on spreading awareness and imparting proper training to the industry on the latest, environment-friendly techniques and solutions for laying flexible pavements. The panel discussed a variety of issues associated with the practical application of IRC standards.
On-site requirements are quite different from the standards prescribed in theory. Besides, in the case of a number of road projects, contractors do not have the flexibility to opt for the appropriate technique for construction.
Further, there is scope for the adoption of advanced technologies in the road construction industry that can facilitate detailed analysis of pavements so that they can be made more efficient and economical. The government should encourage research institutions and other players in the industry with technological expertise to share their experiences with consultants and contractors and help them gain insights on the costs, benefits and effective application of the latest technologies avaialble in the industry. That said, value engineering has immense potential in the Indian road construction industry, since it supports an incentive structure which ensures that the gains from the use of greener technologies are shared equally by all stakeholders in the industry.
In this regard, the World Bank has been taking noteworthy initiatives in collaboration with the government to facilitate technology infusion in the country. The bank has been focusing on the three key aspects of road construction – material, machinery and method. In the past decade, the central government provided excise exemptions to contractors for road projects funded by the World Bank. Apart from this, the bank has showcased itself as a lighthouse when it comes to imparting training and guidance to contractors, supervisors and operators on efficient utilisation of the latest technology solutions. On the policy front, it has been playing a key role in establishing and upgrading the codes and standards for road construction.
NHAI has been taking a number of steps to minimise the environmental consequences of road construction. The authority has recently started mixing waste plastic with bitumen for laying pavements to reduce the carbon footprint. Another step taken in this direction by the authority is the construction of perpetual pavements instead of conventional ones. NHAI has recently issued a circular to encourage the use of waste plastic for road construction. The authority plans to use waste plastic for laying roads spanning about 100 km. However, it is too soon to comment on the feasibility of the plan, given the challenges involved in the segregation and processing of waste plastic so as to be able to use it for road construction. Further, there are concerns regarding the returns from using waste plastic, in terms of actual reduction of the carbon footprint.
Industry experts are of the view that although rigid pavements require lower investments on construction and maintenance as compared to flexible pavements, they are a major source of greenhouse gas emissions. Not only does the material used for rigid pavements contribute to the carbon footprint, but such pavements need to be demolished at the end of their life cycle, which is further expected to have environmental consequences. Considering these factors, flexible/sustainable pavements or “green roads” are usually preferred over rigid pavements for highway projects, despite having a higher construction cost. Other construction technologies such as warm mixes and stone asphalt pavements have also been seen to be performing well. Long-lasting asphalt mixtures have been widely used in most developed countries for construction of sustainable pavments. However, there are only a few private players in the market offering such technologies, creating a monopolistic environment, where such technologies are losing their cost effectiveness for contractors, due to the monopolists charging a high price for the technology. Recycled bituminous pavement material is another environment-friendly alternative used for road construction. The government has recently started applying recycled bituminous material for some road projects in Delhi. Besides, strict rules regarding the disposal of construction and demolition waste are in place in Delhi National Capital Region, which compel road construction companies to opt for recycling.
Going forward, the government should focus on expanding the Make in India programme to encourage the development of the latest green technologies within the country. Further, there is a need for ensuring skill development at the grassroots level, through imparting adequate training and guidance to contractors and operators to ease the process of adopting green technological advancements. Availability of latest technology will not meet the goal of sustainability unless different stakeholders join hands to make road construction in the country environment friendly. India also needs to learn from global success stories where green technologies have been successfully implemented in the most cost-effective manner.