In response to a suggestion from the UK Environment Secretary Owen Paterson that the need for new homes may mean building on ancient woodland sites, the British Cementitious Paving Association, Britpave, has suggested instead that cement be used to stabilise soil on remediated land.
Paterson’s argument was that damage to ancient woodlands could be offset by planting new trees – and more of them – elsewhere. However, Al McDermid, Chairman of the Britpave Soil Stabilisation Task Group, argues that such measures should be a last resort.
“Before building on ancient woodlands the full potential of building on brownfield land should be realised,” he said. “According to the Campaign to Protect Rural England, government figures show that the amount of brownfield land becoming available for re-development is far outstripping the rate at which is it being used. There is enough for 1.5 million new homes.”
Brownfield land is often more difficult to use than greenfield sites, particularly if the site has been contaminated by previous industrial use. The traditional approach to this has been to simply dig up the problem soil and dump it elsewhere. This is not the most sustainable or cost effective approach. “A far better approach is to deal with the problem there-and-then,” explained McDermind. “Insitu remediation and improvement of poor quality brownfield land using cementitious materials to solidify and stabilise the soil removes the cost of lorry movements, landfill taxes and importation of virgin aggregate. It also has a significantly reduced environmental impact.”
Using cementitious binding materials such as cement, lime, flyash or ground granulated blastfurnace slag (GGBS) renders potential contaminants immobile and unleachable. Stabilisation of the soil treats the contaminants to produce a soil that is less toxic. Solidification improves the physical properties of the stabilised soil to provide a strong engineered construction material.
“Soil stabilisation/solidification is a most effective way to bring brownfield land back into productive use,” said McDermind. “Of the estimated 61 920 ha of brownfield land in England, 54% is derelict or vacant. Soil stabilisation/solidification could help bring this land back into use and so negate the need to dig up our ancient woodlands.”
Ancient woodland is classed as areas that have been continuously wooded for over 400 years. A third of woods in England are ancient, covering 350 000 hectares.
Adapted from press release by Katherine Guenioui
Read the article online at: https://www.worldcement.com/europe-cis/14012014/britpave_encourages_utilisation_of_brownfield_sites_590/