Construction and demolition waste (CDW) materials are produced due to constructing, renovating, repairing or demolishing building structures. These structures include roads, shopping malls, houses, bridges, dams, utility plants, and piers. The waste is produced across various stages of construction, from design to procurement to actual construction. Despite the careful balancing of the cost estimation and bill of quantities (BoQ) in a construction project, leftover construction material is always left behind. This material is often discarded into landfills as waste materials or resold or reused if it has an intact shape.
Graana.com discusses the prospects of reusing construction and demolition waste material for slum development to ensure sustainable construction waste, minimise construction waste, and slum up-gradation.
The Dilemma of Over-Used Landfills
The construction industry is one of the topmost contributors of waste materials worldwide in all phases, from raw materials extraction and manufacturing to actual construction or subsequent demolition. Almost 50% of raw materials are consumed by the construction sector, indicating the extent of its unsustainability. These construction materials are a burden on existing landfills and the surrounding environment.
In Pakistan, no proper guidelines for compliance and monitoring over the landfill areas have been enforced so far, apart from a draft on guidelines for solid waste management. In Islamabad itself, proper landfill areas are yet to be marked and developed as the Capital Development Authority (CDA) announces eradicating I-12 landfill and slum areas. In Pakistan, open dumping into landfills is common practice with grave consequences for the environment. This one-way approach towards construction materials is unsustainable as landfills exacerbate air, land, and water pollution and aggravate the scarcity of raw materials. With an increasing population, rapid urbanisation, and slum proliferation, the land becomes scarce with an unregulated consumption of natural resources.
It is high time Pakistan’s construction sector refocuses attention on waste management by imparting education and training and embracing sustainable solutions.
Construction Waste Materials
- Wood Panels
- Untreated Timber
- Plastic (films, wall covers, PVC pipes)
- Ceramic Tiles
- Masonry (bricks)
- Sand, soil, & gravel
- Lumber, flooring, plywood, etc.
- Metals (aluminium, copper, etc.)
Redirect Construction Waste Materials to Slums
Rapid urbanisation, construction, and slum proliferation – all go hand in hand. The solution lies somewhere in between following the lines of circular economy and zero waste concepts. Here are some ways to redirect the construction waste towards slum development:
1. Learn to Earn Model (LEM)
A research study published in Science Direct proposed the concept of LEM whereby recycling workshops for treating construction waste material can be planted near slum areas. It further provides for the slum populace valuable skills and techniques to recycle and reuse waste materials to produce new products or use them to develop streets or houses within the slums. Such a model can be successful with the collaboration of public authorities and private companies pursuing corporate social responsibility (CSR) projects.
The scavenging of valuable items from waste materials is common in Pakistan’s informal economy, conducted by sweepers, slum dwellers, and impoverished women and children. Therefore, formalising this practice through the LEM model has potential in developing countries like Pakistan.
2. Specific Products
Metals like copper, brass, and aluminium can make more metal products and parts that slum residents can sell.
Rubble, concrete, or asphalt can be treated as aggregates for repairing open drains or muddy streets. The usage of recycled aggregates is a rising sustainable practice for diminishing CDW in the developing world.
Any leftover electronics, appliances, or sanitary equipment like public toilets or basins can be donated to these areas.
Lumber and wood can be used as biomass or mulch.
Cardboards, intact plastic crates or containers, sheets, or other materials for reuse in slum houses.
Remnant construction materials can be used to strengthen ‘Kachay Makan’ (non-concrete houses), schools, or clinics. The options are endless.
Cement can be used within its expiration timeframe to construct pots and vases or other valuable household items like utensils, cooking structures, strengthening drains, etc.
3. Portable Shelter Homes
Leftover wooden planes, glass, containers, and tin can be used to construct various mobile shelter homes that are cost-efficient and sustainable for homeless people and slum dwellers who shift around. These concepts might sound advanced but are pretty simple to be executed. The widely famous ideas include:
a. Shelter on Wheels: Such a mobile shelter is supplemented with a wheel or can be attached with a cycle, cart, or any other vehicle.
b. Live-Work-Play Shelter: These shelter homes have the capacity for a dweller to work and live within the shelter home, making them financially independent.
c. Shared Shelter: These shelter homes with partitions can accommodate small families.
4. Repairing Dilapidated Schools
Private construction companies can redirect leftover wood pieces, tiles, steel, or iron to strengthen the dilapidated slums schools or construct new ones. The wood can be used to make desks and chairs for donations to schools in bad shape. Donations can also be made to NGOs and charity organisations running schools in low-income areas or slums. Such CSR initiatives can serve both the low-income groups and protect the environment by reducing waste.
5. Planting Tube wells
Using bricks and stainless-steel pipes, tube wells can be dug up and maintained where water access is an issue. With leftover construction materials, the CSR budget can be used to build these wells at a lower cost in these areas.
6. Repairing Streets
The collected waste can be treated to form aggregates for levelling the streets in low lying areas. Concrete, for instance, can be recycled to create a base for levelling footpaths or narrow streets in slums. Leftover asphalt can also be used for this purpose.
7. Collaboration with Planning and Development Authorities
The responsibility of waste management and efficient urban planning comes directly under the city planning and development authorities. In Pakistan, where 40 million urban population dwells in slums, there is an urgent need for public authorities to address the issue of waste management and slum eradication. They cannot possibly relocate and evict such a vast population. Hence the available option surrounds slum upgradation. They can do so by partnering up with the private sectors’ CSR umbrella to target slum areas, particularly construction companies that are well-versed with city planning, building structure, civil engineering, and urban development.
Capital Development Authority, for instance, can collaborate with private companies like Pepsi, Coca Cola, Imarat Group of Companies, or NGOs like UNESCO, WHO, UNDP to devise convergent plans for resolving the interrelated issue of slums and waste proliferation.
This project reduces solid waste by encouraging people to resell and buy reclaimed or recyclable building materials. In the United States, there are around 1,300 reuse centres that collect donations of construction materials and resell them to the public at a lower price. Somewhat different, this project is a highlight of how innovatively construction waste can be reduced.
Green Exchange Programme
This program is in Brazil, whereby innovative waste management policies have been enforced. The slum dwellers must collect garbage and distribute it to reuse and recycle centres in exchange for free public transport and fresh vegetables. This approach improves their financial health and encourages them to clean up their areas as well.
Suppose the field experts do not contribute to mitigating rampant urban planning issues with the public authorities. In that case, these unsustainable issues will continue to increase and haunt the future generations of our cities and towns. The construction sector should integrate the 3 R’s of Reduce, Reuse, and Recycle to mitigate environmental challenges. The approach of redirecting CDW to slum development is sustainable and representative of corporate social responsibility, inclusivity in urban planning, equity, and welfare. If we avoid these issues, the rapid urbanisation and construction development rate will create a natural, social, environmental, and economic imbalance in our cities. Hence, it has become time to converge the role of public and private spheres in resolving these two issues through a cohesive waste management and slums upgradation policy.