Carillion reveals recycling merits

by Paul Howard



Carillion's work on the Farnborough Business Park development for Slough Estates reveals the cost savings that can be made from recycling and re-using material on-site. For every cubic metre of material that is recycled into a grade that can be used as structural fill, Carillion saves £26.93.

The cost of recycling this material amounts to £6.50/m3, compared with a total of £33.43/m3: £13.43/m3 for removing unsuitable material and £20/m3 for replacing it with suitable structural fill.

Carillion and principal subcontractor PJ Carey's are using a range of plant to recycle the unsuitable material which is being used to raise the level of the development plots.

Currently more than 35,000m3 of material is being fed through an Extec RoboTrac screener to produce 25,000m3 of less than 75mm structural fill. Subject to weather conditions a 13t Case excavator supplies the screener on a full-time basis, while a range of Fiat Hitachi loading shovels and 30t Volvo ADTs are used to remove the oversize material and stockpile the structural fill.

Once screened the material is then distributed across the site and rolled and compacted to 95%. The quality of the material is such that it is unlikely that lime-stabilising will be necessary prior to further construction work.