Unearthing the types of recycled aggregates in construction
The construction industry is a significant contributor to the global demand for raw materials. Traditional construction methods rely heavily on virgin aggregates – crushed rock, gravel, and sand – extracted from natural materials. However, a sustainable solution is gaining traction, with more environmentally-conscious sites opting to choose different types of recycled aggregates.
In this blog post, we look at what they are, and what types of recycled aggregates are available for the construction industry. Let’s tuck in.
What are recycled aggregates?
Recycled aggregates are created from leftover construction and demolition waste materials that have been repurposed by being processed into usable products for new sites and projects.
In a more eco-conscious construction world, demand for recycled aggregates seems to be increasing. According to the Mineral Products Association (MPA), total volume in Britain reached a record 73.5 million tonnes in 2022, a record breaking figure!
Where do recycled aggregates come from?
There are many different types of recycled aggregates, however, most commonly, recycled aggregates arrive from construction and demolition debris such as leftover concrete, asphalt, brick, and ceramics. All these materials will then be collected from a construction site and crushed into various sized fractions, rather than being sent to waste.
By crushing the materials, they are repurposed into valuable resources for future construction projects. By opting to choose recycled aggregates, you’re giving materials a second life and avoiding more waste ending up in landfill, contributing to a more circular economy.
Types of recycled aggregates
When opting to go the recycled route, are two main types of recycled aggregates commonly used instead of virgin aggregates, these are:
Recycled concrete aggregate (RCA)
Made up of leftover concrete waste, crushed concrete, or RCA, is an adaptable material that is perfect for various construction applications.
Recycled mixed aggregate (RMA)
Made up of a mix of concrete, brick, asphalt, and other construction debris, RMA is often used in non-structural applications due to not being as sturdy as concrete.
Use of recycled aggregates in construction
Recycled aggregates offer a sustainable and cost-effective alternative for several construction applications throughout a project. Here’s a breakdown of some key uses typically benefiting from recycled aggregates:
Road construction and pavements
RCA is a popular choice for road base layers and sub-base courses in road construction. The strength and durability of the material make it suitable for handling heavy traffic loads. Additionally, recycled asphalt pavement (RAP) can be reprocessed and used in new asphalt mixtures, reducing the need for virgin asphalt and creating a more circular approach to road construction.
Concrete production
Crushed concrete can be included as a partial replacement for virgin aggregates in new mixes. This can be beneficial for non-structural concrete applications like pavements and initial foundations.
Backfill and Site Development
RCA is well-suited for backfilling trenches, utility lines, and around structures. Its compacted form provides a stable base for future construction activities.
Benefits of recycled aggregates in construction
The advantages of using recycled aggregates in construction are endless, making them an excellent choice for sustainability-minded builders.
Sustainability benefits
Minimise waste being sent to landfill
Construction and demolition waste is a major contributor to overflowing landfills. Recycled aggregates divert waste material from landfills, promoting a more circular waste management approach to construction projects.
Conserve natural resources:
Extracting virgin aggregates, such as MOT Type 1 and 6F2, disrupts wildlife due to needing natural resources to create them. Using recycled materials reduces the need for increased disruption, preserving natural landscapes.
Reduce carbon footprint:
The production of virgin aggregates requires significant energy consumption. Recycling existing materials reduces the environmental impact associated with material production and transportation. With less materials being used; it subsequently reduces the need for transportation to and from production lines.
Economic benefits
Reduced costs
Recycled aggregates are often less expensive than virgin aggregates due to reduced extraction and processing costs. Whilst some construction sites may question material quality with recycled alternatives, if done right, this can lead to significant cost savings.
Reduced transportation costs:
Recycled aggregates are typically sourced locally, reducing the need for long distances of transport and associated fuel consumption. Not only will this reduce carbon emissions, but it also reduces the cost of transport.
Limitations of recycled aggregates
Check material durability and strength:
Studies have shown that well-processed recycled aggregates can offer performance comparable to virgin aggregates in many applications. A great example of this was the road maintenance project carried out in Oxfordshire in 2023 that used the latest low carbon recycling technique. This project saw the road resurfacing being completed by recycling the top layer of old road surface before a new surface is added.
However, it is crucial to ensure that the provider you are using has a strong reputation for providing of recycled aggregates and can assure you of durability for the material.
Data challenges
In a recent report ‘Construction Aggregates Supply in Great Britain’, it was confirmed that 60.3 million tonnes of recycled aggregates in the UK arrived from construction and demolition waste, a leading figure in Europe. However, the report also highlights challenges the industry is having with gaps in data.
The introduction of Digital Waste Tracking in 2025 should play a major role in the availability and quality of construction and demolition waste data, helping identify opportunities for improvement and potentially increase an already respected recycling figure.
To summarise…
By embracing recycled aggregates, the construction industry can significantly reduce its environmental impact and contribute to a more circular economy. From reducing landfill waste to conserving natural resources and lowering carbon emissions, the benefits are undeniable. By choosing an approved and reliable recycled aggregates supplier like Reconomy, we ensure the best delivery of recycled aggregate to help meet your site’s sustainability goals.