Stone reserves in the UK are in limited quantities which makes finding a sustainable alternative that doesn’t require raw stone material an important issue. By recycling demolition wastes we can reduce the amount of stone needed to meet the demand of the construction industry.
In 2020, recycled aggregates made up 25% of the total aggregate supply in the UK so we think it’s important everyone understands the basic process in how they are produced.
The process our producing recycled aggregates is like that of their quarried counterpart. The major difference comes in how the material is sourced. Recycled aggregates look to use waste whereas quarried aggregates use raw material from stone reserves.
Firstly, the correct waste materials need to be located. These materials are often found on demolition projects, where buildings are torn down. The demolition process breaks the waste down to a manageable size.
Materials such as bricks, hardcore and concrete are used to produced recycled aggregates. You only want to accept ‘clean’ materials which aren’t contaminated with plastics, metals, and soils.
The waste materials need to be transported to the processing plant. This can either be on the site or origin or a specialised processing centre.
Dump trucks will transport the material on the demolition site, however, if the material is being hauled off site, tipper wagons will be used to move the waste. In the UK this must be done be a registered waste carrier.
The processing of recycled aggregates can exceed that or quarried materials. This is because the waste needs to be scalped and screened to ensure any unwanted materials are removed before crushing.
Once the waste is ‘clean’ it will be crushed down to the correct aggregate grading and can be used in place of quarried aggregates.
Recycled aggregates must be produced in accordance with WRAP’s Quality Protocol: Aggregates from inert waste.