Bricks, cement and concrete are the bulk of the materials used in the construction sector and hence soil, sand, stone and limestone are identified as the most critical resources. Criticality is based on the associated scarcity of the resource against the projected demand thus enhancing the supply risk. The other distinguishing factors include environmental impact, embodied energy, lack of recyclability, cost and conflict of use.

Use of secondary raw materials in place of critical resources is a good practical approach that could be adopted to decouple the resource usage and the construction sector. Since the environmental footprint of materials used in the construction sector is high, it also offers a great potential for resource conservation, primarily through the productive recycling and manufacture of secondary raw materials from the use of construction and demolition waste.

Like many other developing countries, India also generates huge quantities of Construction and Demolition Waste (C&D) each year. In 2001, the Technology Information, Forecasting and Assessment Council (TIFAC) estimated that the national annual C&D waste generation was around 12 to 14.7 million tonnes. In 2013, the Center for Science and Environment (CSE) placed the estimate at 530 million tonnes. Extrapolating the data as per expected population growth, it would appear that India will generate approximately 2725 million tonnes of C&D waste annually by 2041.

Good practices from developed cities in different parts of the world show that almost all C&D waste can be effectively reused or recycled back into secondary raw materials. C&D waste management is still a huge challenge for India since proper estimation, management practices or treatment facilities do not exist in majority of the Urban Local Bodies (ULBs) in India. The good news is that the pilot facilities in Delhi and Ahmedabad prove that C&D waste can be recycled and reused in India in a socially, technically and financially viable manner.

In order to create a national level momentum and up-scaling the processing of C&D waste, legislative frameworks and policies need to be implemented in the country. This needs to supported by creation of better standards for ensuring quality of recycled products and also creation of technology hubs and decision making bodies to promote specific upcoming technologies in this sector.

Effective legislative framework has proven to be the backbone of success of proper C&D waste management practices in several countries around the world. Understanding the need of strong legislative intervention, the Municipal Waste Management Rules 2015 has several amendments which are aimed at proper streamlining of C&D waste management in India in due course of time. Unlike the previous version (Municipal Solid Waste Management Rules 2000) where no specific guidelines was given for the management of C&D Waste, in the 2015 draft version a separate chapter (Chapter 2) is included for the Management of C&D Waste which gives the responsibilities and timelines for implementation for each of the stakeholders involved with the management of C&D Waste.

The new rules set a benchmark for waste management, but it is critical that capacity development is imparted to each stakeholder on how to implement these rules and it needs to be monitored properly. In addition, the rules need to include what are the penal actions to be taken for non-compliance which is an important aspect of implementation of rules.

Policy level interventions are critical to mainstreaming the use of recycled C&D waste and other secondary raw materials. As part of the Swachh Bharat Mission in India, policy interventions have been initiated for C&D Waste management and recycling on a national scale. The Union Cabinet chaired by Prime Minister Narendra Modi has approved the signing of a Memorandum of Understanding (MOU) between SINTEF, Norway and Central Public Works Department (CPWD) for cooperation in the development of human resource capacity building and scientific research in the field of recycling of C&D Waste in India.

Similar policy interventions in the form of Sustainable Public Procurement, Regulations and Bans and Fiscal Incentives need to be implemented in different levels of decision making from the national level to the local governing body level. This also has to be implemented in a systematic and scaled manner if a large scale change needs to be achieved. The policy changes adopted for upscaling the use of flyash bricks in Bihar is the kind of approach that needs to be adopted for C&D waste.

As a proactive approach to the legislative requirement of the national level standardisation bodies, the Bureau of Indian standards (BIS) in its revised third version of IS 383:2015, the Indian standard for coarse and fine aggregates for concrete specification has specified the standards for manufactured aggregates produced from other than natural sources (along with primary sources), for use in the production of concrete for normal structural purposes including mass concrete works (Yajjala, 2015). The processed aggregates have been classified into Recycled Concrete Aggregates and Recycled Aggregates for specific applications in concrete. In addition, the National Building Code (NBC 2005) also addresses the usability of processed C&D waste for construction purposes.

The standards specifications are based on experimental results and the latest standards. It has been observed that even though standards for secondary waste material are added in the specifications only partial replacement and mostly only recycled concrete aggregates are included in the standards. Although proven technologies are adopted in Delhi and Ahmedabad, C&D waste processing plants where complete replacement of aggregates is made using processed C&D waste, enough upscaling or streamlining into the system has not been made. Hence constant effort and up gradation in terms of standards in national level organisations supported by other interest groups is required to provide proper standards that promote further use of processed C&D waste.

A hurdle usually faced in the use of secondary waste material streams like C&D waste is the availability or more over the accessibility of technologies. There is often a technology gap in knowing where to go and to seek solutions i.e. lack of technology and service providers and resource hubs. The technology gap exists among entrepreneurs and even decision making bodies at the state and national level. The lack of such support often deters the possibility of waste management ventures.

The International Resource Panel is a platform of a panel of experts, whose work is designed to support such efforts, hopefully leading to an effective transition to a Green Economy that enhances human welfare while sustaining environmental resources. It promotes decoupling by investigating the world’s most critical resource issues with a view to developing practical solutions for government, policymakers, industry and society (Development Alternatives, 2014). Understanding the need of a similar national level body, the Indian Resource Panel (InRP) was formed in November 2015 to act as a hub for resource efficiency and support policy makers with the right kind of policy and technology support. Resource efficiency in the construction sector is a prime agenda of the panel.

India is the first nation to implement a national level resource panel and hence is an important milestone towards resource efficiency. The resource panel is a platform, but it needs inputs from interest groups like think tanks and research organisations in the nation in order to formulate solutions to the existing situation. Data availability in the C&D waste management sector is almost nil in most ULBs. C&D waste management and processing depends on the quantum, characteristics and construction and demolition practices in a region, hence data collection regarding C&D waste needs to be prioritised and more research programmes need to be implemented in the country. These programmes need to be region and area specific in order to deliver custom made solutions. q