Scott Bros on the road to a greener future

Recycling firm prepares to start production of low-carbon concrete using waste filter cake

NORTH East recycling specialists Scott Bros are to install a new plant on the site of their £6 million washing facility over the next few months, allowing the company to produce low-carbon concrete.  

Scott Bros are already working with Teesside University on a series of trial mixes to find out how much they can reduce the amount of Ordinary Portland Cement (OPC) which is used as a binding material.

In recent years, the family-run business has been recognized for going the extra mile to make practical use of fine-grained clay (also known as filter cake) – a waste by-product from its two urban quarries that convert construction and excavation waste materials into high-quality sand and aggregate.

The silicate clay-rich filter cake, which has cementitious properties, is currently used as low-value BS-certified pond lining material or inert engineering fill. Most binding materials used in traditional concrete consist of Portland cement, but it can be significantly reduced by using the filter cake as an alternative.

The work using Teesside University’s science, engineering, and digital technology resources has seen a series of experiments to determine exactly how much OPC can be replaced by the filter cake material while still achieving the same strength and durability as traditional concrete.

Cement is currently produced by an energy-intensive process involving high volumes of raw materials. The process accounts for an estimated 5-8% of global carbon dioxide emissions, with many countries expected to increase demand for this vital construction material in the coming years.

The £612,000 collaboration project between Scott Bros and Teesside University’s School of Science, Engineering & Digital Technologies is being funded by Innovate UK – part of UK Research and Innovation (UKRI) – a government innovation agency that drives productivity and economic growth by supporting businesses to develop and realize the potential of new ideas.

Scott Bros director Bob Borthwick said: ‘The new plant will enable us to replace a significant amount of OPC with filter cake to create low-carbon concrete. By adopting this alternative formulation, we can significantly reduce the large carbon footprint associated with traditional concrete production using a waste material that might otherwise end up in landfill.’

Fellow director Peter Scott added: ‘This is a major step forward for the region’s circular economy. Transitioning away from traditional OPC toward more environmentally friendly alternatives is crucial for a greener future in construction. Such innovation paves the way for a more sustainable and resilient built environment.’