If you reside in a city anywhere in the world, you will see construction happening left, right and centre. New buildings are being made and old buildings are being demolished to make way for new construction. All the demolition leads to the production of waste known as construction and demolition waste or (C&D) waste. The disposal of construction waste is a huge problem for developers, builders and owners, and is often dumped into landfills. This demolition waste can actually be recycled and reused in the construction of new buildings, which can help to reduce the use of depleting raw materials.
Awareness about the utilization of demolition waste is essential
Utilizing the C&D waste is a comparatively new concept and there has to be more awareness about the importance of it. Most owners are unaware about the potential of demolition waste and builders and developers may be apathetic towards the issue or don’t have the required expertise to carry out environmentally friendly C&D waste disposal and reuse/recycling.
The government and non-governmental agencies have to make more efforts to spread awareness about reusing all the materials generated during demolition. There has to be proper rules and regulations in place which would ensure that all material which can be used is used in other projects, as construction industry consumes a vast amount of natural resources. The government can give incentives to builders who follow sustainable building methods.
Which type of C&D material can be reused?
Reusing of demolition waste is different from recycling. Materials which can be reused do not require any further treatment to transform it into useful products. They can be retrieved from the waste and put into use.
Bricks are in good shape or full bricks are screened from the C&D waste can be used to build partition walls.
Reusing construction waste is much more advantageous as it does not require any additional energy to make it usable, builders should make a plan for demolition. Having a plan for demolition will allow useful products/materials such as windows, doors, reinforcement, bricks and structural steel can be extracted carefully. After the reusable materials are extracted, the demolition waste left over can be kept for recycling.
What does a demolition plan entail?
A demolition plan is needed to execute a systematic demolition. The first step could be segregating household waste, then extracting electrical and mechanical equipment, interior and exterior finishing materials, water proofing and roofing materials, then demolishing the structure at the end.
The C&D waste should be shifted from the site immediately and stored safely on a temporary basis in a previously designated area.
C&D materials which can be recycled
Concrete is composed of coarse and fine aggregates, cement and water, and other industrial additives to enhance the properties. The aggregates are mainly natural materials like sand. Sand and water are becoming scarce which is why builders should recycle construction material, which can conserve a huge amount of water and aggregate. The effort should be to use treated waste water in construction, as potable water tables are depleting day by day.
RCA or Recycled Concrete Aggregate is an excellent alternative to natural materials, as it can help to fulfill the need of construction material especially in areas where there is a scarcity of water and aggregate.
Aluminum and steel are products which are obtained as waste after demolition. Steel beams can be used without recycling. Aluminum can be recycled using the solid bonding method. This recycled aluminum can be used for making household appliances. Aluminum can be recycled many times and can be recast into the original form and used again for construction.
Bricks are used in all types of construction in India, residential and non-residential. It makes up for a significant amount of construction material in new constructions and is second to concrete in terms of demand. Bricks have a unique property of being able to withstand the entire life of a building. Thus bricks even when demolished can be used again and again and the brick dust or other parts of bricks which cannot be recycled can come into different uses during construction.
After mortar removal, bricks can be used to construct new buildings, or to pave streets, which is a part of sustainable building methods. Brick paved streets are quite attractive, and allow water to flow through.
Plastic is repurposed into different products such as plastic tables, lumber, benches, stationery and other products. A new use of plastic is to prepare road surfaces which are resistant to water. Alternates to plastic should be developed as recycled plastic cannot be recycled again, thus ending up as waste in oceans and landfills.
Broken tiles can be crushed into aggregate which can be used in construction. Tiles which are broken into small pieces can be extracted and used as art material for murals, sculptures. Tile pieces can be used to make table tops, drive ways and subways etc.
Glass can be recycled to make room dividers, lighting fixtures, and many other products.
Wood waste can be recycled to make particleboard, fiber board, animal bedding or to generate renewable energy. Chipped/shredded wood can be used as sludge bulking medium in sewage and in lime pallet products.
8. C&D waste recycling factory in New Delhi
The concept of recycling construction waste is brand new in India, and therefore there is only one facility which has been set up in Burari, North Delhi. The city, as well as the rest of India requires many facilities like this, in order to recycle the approx 5000 metric tons of construction waste generated daily in Delhi.
Concrete is now a material which is so expensive to produce with the use of latest equipment that economists measure a country’s economic strength by the amount of cement it produces! Aggregates used for concrete are also depleting fast. In this scenario, reusing and recycling C&D waste as alternate materials will reduce the use of natural materials.
The government should start setting up laws forcing builders to use reused and recycled materials, as well as demolishing responsibly. There should also be public awareness campaigns so that owners/builders/developers can also take steps necessary for systematic demolition.