Soil stabilisation could help realise brownfield land fund objectives

Britpave, the infrastructure association, believes that the use of soil stabilisation to address problem brownfield sites to bring them back into productive use will help forward government proposals to invest £1bn from the Brownfield, Infrastructure and Land Fund (BIL) to build 40,000 homes and 200,000sqm of employment floorspace.

The BIL fund covers Homes England’s land, grant and equity objectives of bringing forward strategic sites and housing-led opportunities which support economic growth and long-term housing supply.
At least 60% of activity will be focused on brownfield land - land that has been previously used and is now vacant, derelict and sometimes contaminated.

Soil stabilisation can help bring those sites back into productive use believes Al McDermid chair of the Britpave Soil Stabilisation Task Group. He said: “Soil stabilisation can sustainably and cost-effectively improve the soil condition of sites previously thought unsuitable for development or can be used as part of remediation strategies to successfully address past industrial brownfield sites. These sites then offer a real alternative to using greenfield sites.”

Using cementitious binding materials such as lime, cement, fly ash and ground granulated blast furnace slag (GGBS), soil stabilisation can treat contaminants within the soils, on site, to provide a material that is safe to use in construction and provides with a greatly reduced risk of leachate contamination to the wider environment.

“The traditional approach to re-use brownfield land is to simply dig up the problem soil and dump it elsewhere. This is not an environmentally sustainable or cost-effective approach,” explained McDermid. “Dealing with the problem on site minimises the cost and nuisance of lorry movements, negates the need to pay landfill taxes and removes the need to import virgin aggregate.”

However, he warned: “Soil stabilisation involves a lot more than a tractor simply churning up the ground and scattering over some binder. Soil types and possible contaminants need to be assessed and tested so that the correct binder can be administered. Handling binders correctly requires a proper health and safety protocol. It also requires the use of specially developed plant to ensure that the mixing and placement of soil and binder is efficiently undertaken. As with all things, the best results are achieved when it is carried out by experienced best practice contractors.”