Utility excavations have never been more financially challenging. It now costs £6/tonne to send excavated spoil to landfill – an increase of 100% from 2006 – and bedding materials (fines) for pipes and grade one fill are ever more expensive. There’s also the impact on the environment of continually using virgin materials.
 After researching potential alternatives, including a fair amount of trial and error, Turriff is now piloting a system which could have a major impact on the approach of utility and highways contractors to recycling.
The Turriff approach is called GreenROAD – Recycling Of As-Dug materials – and is the brainchild of chairman, Ellis Duguid. There are on-site and off-site GreenROAD systems but both follow the same three-step process:
- Step 1 – As-dug material is fed into Turriff’s mobile crushing unit which breaks down the rocks, stones and lumps of asphalt. At this stage, any foreign materials such as metal or plastic are removed.
- Step 2 – The output from Step 1 is passed over a vibrating mesh which separates the fines from the crushed stones. The outputs from Step 2 are fines for bedding pipes, and material which can be used for initial reinstatement.
- Step 3 – Soil stabilisation material can be added to the crushed stone which, if approved by the relevant highways authorities, can be used as highways work reinstatement: the final stage before new asphalt is laid.
 Ellis is very excited about the prospects for GreenROAD: “The plant costs for each off-site GreenROAD installation are about £225,000 - so it’s not a cheap option. The aim for on-site and off-site GreenROAD is for it to recycle materials from Turriff’s utility excavations. All utilities have ambitious recycling targets – SGN, for example, is aiming for 75% - and GreenROAD will make a major contribution as it achieves recycling rates of 95% and more.” |
