As individuals, we are all well used to recycling plastics, paper, and glass, but industry needs to become just as active with the way they recycle the materials they use and the waste they produce. For the construction industry, this hinges on finding the best ways to recycle concrete.
Concrete is the second most widely used substance in the world. It is also one of the heaviest sources of waste, or more specifically, CDEW, Construction, Demolition, and Excavation Waste. CDEW makes up more than a third of all waste. Within the UK, this means around 120 million tonnes of waste, which also leads to a significant level of CO2 emissions.
Given the volume of waste and its environmental impact, it is no surprise that efforts to recycle concrete have ramped up, particularly as there are so many economic and environmental benefits and so many ways recycled concrete can be used.
WHAT IS RECYCLED CONCRETE?
Recycled concrete is an aggregate material made from concrete reclaimed from demolished structures and roads. It provides a material that can be reused in new projects rather than being sent to landfill sites, which not only impacts the environment but also generates even more harmful emissions via the transporting process.
The process is relatively straightforward and tends to involve four steps:
- Concrete rubble is collected from demolished constructions either at a recycling facility or onsite.
- Having been harvested, the concrete is crushed together using heavy-duty crushing machines. This can be followed up with additional processing using a cone crusher if the rubble needs to be sized.
- As concrete is often mixed with other materials like dirt, plastic, clay, asphalt pavement, or metal, the aggregate needs to be screened so these materials can be removed depending on how the aggregate is planned to be used.
- All unwanted residue is then removed by hand, by using air, water, or magnetic separators.
In terms of the aggregates that can be produced by recycling concrete, there are two main types:
- Recycled Aggregate (RA), an aggregate produced by reprocessing inorganic materials that has been used in previous construction projects.
- Crushed Concrete Aggregate (CCA), an aggregate made from crushed concrete.
These account for approximately 29% of the total aggregate use in the UK, which means recycled concrete is having an increasing impact on the UK’s efforts to adopt circular construction by reducing the demand for primary aggregates.
HOW CAN RECYCLED CONCRETE BE USED?
Recycled concrete can be used for a wide range of construction projects. Almost any type of building that needs concrete can use recycled concrete, and common uses include landscaping and retaining walls, filling foundations, and providing sub-base material for roads and walkways.
However, recycled concrete is also being used to support more environmentally focused initiatives. In 2013, an artificial coral reef was constructed by a collaboration between an airport and a local contractor off the coast of Florida using concrete taken from the recently demolished parts of the airport. The new reef was constructed specifically to give fish protection from predators so that a diverse collection of marine life could flourish.
Given the environmental and economic benefits of recycling concrete, we would expect there to be a continued drive to improve the harvesting, crushing, screening, and cleaning processes. This could take the form of new machinery employing new parts and functionality. It is equally likely to involve more sophisticated digital controls or, given the sustainable aims of recycling, the adoption of more energy-efficient and emission-conscious technologies.
However innovation develops, it is absolutely essential that the companies driving the sector take the time to identify and protect their hard work and support new initiatives and collaborations with the requisite commercial contracts. This is where we can help. We will secure the patent protection you’ll need to progress the commercialisation of your inventions, fully supported by the required commercial agreements.
