Secondary materials The works involve the largest use of secondary materials on a road project in the UK.
Recycled concrete will be sourced from the demolished structures on site and the surrounding area, and combined with recycled pavement material to form 50,000m 3of capping, avoiding the need to import rock from local quarries.
A new performance specification is being specially developed for this capping material by Scott Wilson Pavement Engineering.
The new-build London bound carriageway will use lime, ggbs, (ground granulated blast furnace slag) and cement bound materials to stabilise the chalk sub-grade, to avoid importing capping and crushed rock sub-base.
Pavement design has yet to be finalised, but is expected to use quiet asphalt surfacing.