Brown field sites previously judged to be too contaminated could be brought back into use if the predicted rise in the UK population from 61m to 71.6m by 2033 is to be accommodated, according to The Concrete Centre.
Currently, brown field sites account for 70 per cent of new homes. This figure will have to increase if development on greenbelt land is to be avoided. As those sites which are easiest to redevelop are used up, attention will have to focus on sites that are heavily polluted and contaminated from previous industrial use. The potentially hazardous nature of the contaminates, plus the EU Landfill Directive requirements that limits the disposal of hazardous waste as landfill, means that the use of cementitious material for remediation of brown field sites will increase.
Using cementitious material for the solidification/stabilisation (S/S) remediation of brown field sites involves rendering the contaminants immobile and virtually unleachable. Using readily available binders such as cement, lime, fly ash or ground granulated blast furnace slag (GGBS), stabilisation treats the contaminants in the soil to produce a form that is less toxic and less available to the surrounding environment. Solidification involves the improvement of the physical properties of the stabilised medium to form an engineered soil, fill on monolith.
Head of civil engineering at The Concrete Centre Alan Bromage said: “S/S is a most effective way to remediate contaminated land and bring it back to productive use. Plus it offers particular benefits. Unlike dig and dump, S/S does not simply dig up the problem and the dump it elsewhere. It solves the problem on site.”
He continued: “S/S is increasingly being adopted in the UK as the way forward to bring back into use brown field sites. The need to provide homes for the UK’s predicted population growth will force councils and developers to review up-to-date technology such as S/S in order to examine the potential of sites previously judged too difficult to be brought back into use.”