HARNESSING WASTE FOR SUSTAINABLE CONSTRUCTION

With the growing construction activities, there is a dearth of construction aggregates as the natural resources for aggregates are depleting. It is time to harness the accumulating municipal solid waste, construction & demolition waste, and other waste materials in meeting the growing demand-supply gap of construction aggregates in future. Construction Times explores the way forward.

India's construction sector is poised for substantial growth with the enormous developments planned for the coming years to meet the needs of infrastructure and real estate sectors. India is witnessing unprecedented growth in urban population with an estimated 50 per cent of India living in urban areas by 2046. This has boosted the construction sector with a lot of urban infrastructure development activities underway and in the pipeline. This will also see a lot of redevelopment activities by demolishing old structures for new ones. The growing urban population is also generating a lot of urban waste which is overburdening the municipal waste management system. 

On the flipside, the growing construction activities demand aggregates in larger quantities than earlier and the natural resources of aggregates are depleting fast, compelling the developers and contractors to look for other alternatives to meet the growing needs. This is where the use of construction and demolition waste (C&D waste) and other urban wastes play a major role to bridge 
the gap.

MSW – from liability to resource

The rapid urbanization and infrastructure development in India pose significant challenges to environmental sustainability, primarily through the generation of municipal solid waste (MSW). As urban areas expand, the volume of waste produced increases dramatically, creating a pressing need for effective waste management strategies. Jose Jacob Kallarakal, Chairman & MD, Antony Waste Handling Cell Ltd, elaborates, “Urbanization has led to a substantial rise in waste generation, with estimates indicating that urban India produces between 1,30,000 to 1,50,000 metric tonnes of MSW daily, projected to reach 165 million tonnes by 2030. This surge not only overwhelms existing waste management systems but also exacerbates pollution and environmental degradation.”

Today, landfills are the most common method of waste disposal, occupy vast tracts of land that could otherwise be used for agriculture, wildlife habitats, or urban green spaces. As landfills reach capacity, they release harmful greenhouse gases such as methane, which significantly contribute to climate change. The decomposition of organic waste in landfills also produces leachate, a toxic liquid that can seep into the soil and contaminate groundwater sources. The mismanagement of solid municipal waste poses serious public health risks. Communities living near landfills and waste disposal sites are often exposed to hazardous pollutants, leading to respiratory problems, skin diseases, and other health issues.

The rapid pace of urbanization often outstrips the development of necessary waste management infrastructure. Local authorities frequently lack the resources and knowledge required to implement effective waste collection, segregation, and processing systems, resulting in inefficient service delivery and increased public health risks. Kallarakal is of the view that despite the introduction of various regulations aimed at improving waste management—such as the Swachh Bharat Mission—implementation remains inconsistent across different regions. Many urban local bodies (ULBs) face challenges in adhering to guidelines for source segregation and door-to-door collection. “Effective waste management requires active participation from citizens, yet public awareness and involvement often fall short. Initiatives that foster community engagement are essential for achieving sustainable practices like recycling and composting, he adds.

In spite of these challenges, these wastes present significant opportunities, provided these wastes are properly collected and recycled. By adopting a circular economy approach, communities can transform waste from a liability into a resource. while growing urbanization presents serious threats to environmental sustainability through increased solid municipal waste generation, it also opens avenues for innovative solutions that can enhance both ecological health and economic growth in developing economies like India. Addressing these challenges with strategic planning and community involvement is crucial for achieving long-term sustainability goals.

C&D waste – aggregates reborn

Construction and demolition activities generate significant amounts of waste, which, if not managed effectively, can pose serious environmental and health risks. According to Persistence Market Research, construction and demolition activities contribute significantly to the global waste burden. C&D waste accounts for nearly one-third of all global waste, with materials like concrete, asphalt, wood, and metals dominating the waste stream. As urbanization accelerates and infrastructure projects expand, managing this waste sustainably has become imperative.

C&D waste causes serious implications on the environment due to illegal irresponsible way of dumping. This uncontrolled disposal reduces the availability of land, leads to land degradation, and creates unsightly dumps that contribute to urban decay. Dust from construction sites, demolition activities, and improperly disposed of materials contributes to particulate matter (PM2.5 and PM10) pollution in Indian cities, exacerbating air pollution. Construction waste, when dumped in water bodies, clogs drainage systems and leads to flooding. C&D waste contributes to greenhouse gas (GHG) emissions. The demand for raw materials like sand, gravel, limestone, and timber leads to excessive resource extraction, deforestation, and damage to river ecosystems.

According to Abhijeet Gawde, Head of Business Development & Marketing, Construction, a part of Godrej Enterprises Group, effective management of C&D waste is essential for sustainable infrastructural growth globally. Most of the C&D waste comprises debris from the demolition of old buildings, roads, bridges, and other structures. C&D waste presents a resourceful opportunity, with nearly 70% of waste potentially recoverable using appropriate methods and guidelines during demolition activities. Concrete, bricks, blocks, and other fine materials form a significant portion of the overall C&D waste generated.

Recycling of C&D waste plays an important role in preserving the environment. It reduces the amount of debris dumped in landfills. By processing and reusing materials, recycling minimizes the amount of dust, toxins, and pollutants released into the environment. Recycling reduces the need for new raw materials, thereby protecting natural ecosystems. Recycling reduces energy consumption by repurposing existing materials, leading to lower greenhouse gas emissions. Recycling C&D waste creates new business opportunities in waste management, material recovery, and green construction. “Recycled materials such as reclaimed wood, crushed concrete, and reused steel are often cheaper than new materials. This lowers the overall cost of construction, making buildings more affordable and encouraging sustainable development in urban areas. Infrastructure projects need to set up their own recycling facilities. “Recycling C&D waste presents a sustainable solution, offering economic, environmental, and social benefits. By adopting efficient waste management policies, investing in recycling infrastructure, and promoting awareness, India can mitigate the environmental damage caused by construction waste and move towards a greener, more sustainable urban future,” highlights Ajit Kumar Jain, IAS (retd), Chairman and Managing Director, ERAF Environment Research Foundation.

Gawde adds, “At the Construction business of Godrej Enterprises Group (GEG), we are committed to a greener tomorrow by adopting more sustainable construction practices. In line with the Circular Economy design principles, we have set up an automated Recycled Concrete Materials (RCM) manufacturing plant in Vikhroli, Mumbai. This plant manufactures a range of prefabricated concrete products using recycled concrete debris from demolished structures, which would otherwise end up in overflowing city landfills.”

Antony Waste is actively integrating recycled materials into its projects as part of its commitment to sustainable waste management. The company employs advanced technologies to process various types of waste, including C&D debris, municipal solid waste, and plastics. “Through its specialized Material Recovery Facilities, Antony Waste efficiently separates and recycles materials, producing high-quality aggregates that can be reused in new construction projects. This not only helps reduce the consumption of natural resources but also minimizes landfill dependency,” says Kallarakal.

According to Dr. Prashant P. Bhave, Professor (Adjunct) & Retd. Professor (Asso.) & Head, Environmental Engg, VJTI, Mumbai, C&D waste management should emerge as a model for SWM by the ULBs as waste generator and need citizen-friendly approach for collection, transportation and treatment or environment-friendly management.

No more waste

The growing demand-supply gap of aggregates and the adverse impact of waste accumulation has opened new avenues for waste recycling and reuse, creating circular economy in every facet of construction and infrastructure developments. One of the notable advancements is the use of plastic waste in road construction, which has been successfully implemented in various projects across the country. Union Minister Nitin Gadkari has highlighted that approximately 246 lakh metric tons of plastic waste have been utilized in constructing around 854 km of roads.

“The shift of road construction industry towards circular economy principles emphasizes cleaner and resource-efficient technologies, chiefly to balance resource extraction and waste generation,” comments Krishna Prapoorna Biligiri, Professor, Department of Civil & Environmental Engineering, Indian Institute of Technology (IIT) Tirupati.

A sustainable Indian construction industry involves a comprehensive shift towards circular economy practices. By integrating recycled materials into construction processes, the industry can significantly reduce its carbon footprints. Collaborations between public and private players, coupled with imparting awareness on the use of properly recycled materials in construction will go a long way for a sustainable construction industry in India.