Article by : Jayasree Nachiyar Palanivel

Nowadays construction and demolition of buildings is very often. Old buildings are demolished and new construction is being replaced at the very same location . This activity results in lot of waste generated in both developed and under developed countries.

Wastes generated at construction sites can be of,

Excavated wastes

Wastes such as soil, asphalt, sand, gravel, rock etc.,.

Construction wastes

Wastes such as concrete, dry wall, plastics, ceramic tiles, metals, paper, glass etc.,.

Demolition wastes

Wastes such as concrete, metal, roofing sheets, brick, stone, wood material, asbestos, gypsum, briquette.

Mixed wastes

Trash and organic wastes.

Plaster board which contains toxic gas – hydrogen sulphide should be treated & then get disposed.

Materials that can be recycled from construction and demolition projects are,

• Woods
• Glass
• Metals
• Tyre
• Plastics

Number of interior designers are also making use of recycled materials in the construction of homes.

• Washed – up beach plastics for floor
• Plastic bottles for furniture making
• Saw – dust create insulation boards

Wood

Cork-wood

Besides using cork in wine and champagne as stoppers. The cut – offs and fragments from the manufacturing process of cork stoppers are collected and used for cork floor tiles

Newspaper wood :

Paper is made from wood. But the old newspapers are stacked and the layers are compressed results in wood like material where the woods look like the grain and rings found in natural timber. This recycled wood is used as kitchen shelves,cupboards and doors.

Glass :

Glass is made from readily available domestic materials – sand, soda ash, limestone & cullet(mostly sand is used) – the industry term for furnace ready recycled glass.

Glass when crushed can be used in construction of walls and road construction. Crushed glass is being used in places where the aggregate costs more and in golf courses to neutralize soil pH. Since crushed glass does not breakdown into any harmful by products such as methane it is ideal in construction purpose.

Crushed glass is also used in many places where natural sand can also be used such as in construction projects. Backfill areas such as trenches and foundation are often filled with crushed glass. Not only glass recycling helps in reducing landfilling but no emission of green house gases and thus prevents pollution.

Metals :

Scrap metals such as aluminum, iron, steel, copper and brass can be reused many times to make many new products.

Recycling of scrap metals further reduces the mining to obtain new metals for manufacturing process.Recycled steel and aluminum are mostly used in new food packaging.Most scrap metals are recycled into components for the home – furnishings, fixtures and lighting, decorative metal work.Modern art work can also be made out of recycled scrap metals. Good scrap metals includes circuit breakers, plumbing, electrical wiring, sinks etc.,.

Tyres :

Since tyres are not Bio – Degradable thus can be used in constructing a new building ends in reducing the dumping of tyres in landfills and stockpiled.It can be used as construction material since it has the property of heat conductor especially the racing car tyres which acts as a heat sinks where the heat get transferred from high temperature to low temperature i.e., heat is removed from the inside house to underground.Its most suitable in tropical climate countries.

a)Rammed tyre construction

Here the recycled tyres are filled with soil compacted which acts as a framing where the gaps are filled with glass or plastic bottles or aluminum cans.

b)Tyre Bale construction

Number of tyres used in this type of construction is more when compared to Rammed tyre construction.It frames the outside walls of the house stacked like bricks to cover the whole house.

Walls of either method is smoothed over with cement then layers of plaster to finish.

Plastics :

Recycled plastics are used in new building and construction applications everyday . This in terms reduces the accumulation in landfills . Upcycling plastics helps to save energy for the production of new plastic products where the recycled plastics combined with virgin plastics(plastics that has not been processed before)such plastics are used to make polymeric timbers – used in making from picnic tables to fences hence trees can be saved. Even a two liter bottle can be spun into fiber and the product obtained is carpet another home appliances.

Plastic Roads

Plastic roads are constructed using plastics as a binder with other material(Bitumen).The asphalt concrete road is replaced with plastics in the plastic road construction.The plastics used in road construction are mostly the packaging product .Some of the most common plastics used in packaging are Polyethylene terephthalate(PET/PETE),Polyvinyl chloride (PVC), polypropylene(PP), high and low density polyethylene(HDPE & LDPE).

These are few examples of recycling in Construction industry . Readers can share new methods which you come across in the comments section.