Construction waste is a major source of environmental pollution and resource depletion. It consists of various materials that are generated during the construction, renovation and demolition of buildings, roads, bridges and other structures. Recycling construction waste can reduce the need for virgin materials, save energy, lower greenhouse gas emissions and create new markets for recycled products.
Here are some strategies for recycling construction waste effectively:
Identify the types and sources of construction waste
Different types of construction waste may require different recycling methods and technologies. For example, concrete waste can be crushed and used as recycled aggregate, while paper and cardboard waste can be reprocessed into new paper products. Some common types of construction waste are:
- Brick
- Concrete
- Ferrous metal
- Masonry
- Non-ferrous metal
- Paper and cardboard
- Wood
- Asphalt
- Gypsum
- Glass
- Plastics
- Salvaged building components
The sources of construction waste can also vary depending on the stage and nature of the project. For instance, design decisions, procurement practices, handling of materials, operation methods and residual activities can all influence the amount and quality of construction waste generated1.
Implement source reduction and reuse measures
One of the most effective ways to reduce construction waste is to prevent it from being generated in the first place. This can be achieved by adopting source reduction and reuse measures, such as:
- Designing for durability, adaptability and disassembly
- Optimizing material use and minimizing off-cuts
- Ordering materials in accurate quantities and sizes
- Using prefabricated or modular components
- Storing and protecting materials from damage and deterioration
- Donating or selling excess or salvaged materials to other users
- Reusing materials on-site or in other projects
Separate and sort construction waste on-site
Another key strategy for recycling construction waste is to separate and sort it on-site according to its type and quality. This can facilitate the collection, transportation and processing of recyclable materials, as well as reduce contamination and disposal costs. Some methods for separating and sorting construction waste on-site are:
- Providing dedicated bins or containers for different types of waste
- Labeling bins or containers clearly with recycling symbols or signs
- Educating workers and subcontractors about the recycling program and procedures
- Monitoring and enforcing compliance with the recycling program
Choose appropriate recycling methods and technologies
Depending on the type and quality of construction waste, different recycling methods and technologies may be available and suitable. For example, some materials can be recycled on-site using mobile crushers or shredders, while others may need to be transported to off-site facilities for further processing or recovery. Some examples of recycling methods and technologies for construction waste are:
- Crushing concrete into recycled aggregate for use in new concrete or road base
- Melting metals into ingots or bars for use in new metal products
- Pulping paper and cardboard into pulp for making new paper products
- Shredding wood into chips or pellets for use as fuel or mulch
- Grinding asphalt into granules for use in new asphalt or road base
- Calcining gypsum into powder for use in new gypsum products
- Crushing glass into cullet for use in new glass products or aggregate
- Pelletizing plastics into granules for use in new plastic products
Buy recycled construction materials and products
Finally, one of the best ways to support the recycling of construction waste is to buy recycled construction materials and products whenever possible. This can create a demand for recycled products, stimulate the development of recycling markets, reduce the consumption of virgin resources and save money. Some examples of recycled construction materials and products are:
- Recycled concrete aggregate (RCA)
- Recycled asphalt pavement (RAP)
- Recycled steel or aluminum products
- Recycled paper or cardboard products
- Recycled wood products or biomass fuel
- Recycled gypsum products or soil amendment
- Recycled glass products or aggregate
- Recycled plastic products
