In April 2015, Concrete Canvas GCCM was used to line a ditch next to the new Bexhill to Hastings link road.
A drainage route was needed to take surface water runoff to a local watercourse. Initially a large diameter pipe was specified, however the poor ground conditions would have required significant temporary works and heavy machinery, increasing costs. Rigid plastic ditch liners were also considered but these were also ruled out because of the cost of preparation works needed. Concrete Canvas was selected as the solution due to its rapid install time and minimal equipment requirements.
Minimal ground preparation was carried out using an excavator to grade the ditch and cut anchor trenches into the shoulders. 13 mm thick CC (CC13TM) bulk rolls were batched down to specific profile length and transported down the embankment by hand before being unrolled transversely across the ditch. The installation team ensured a 100 mm overlap between layers in the direction of water flow, before fixing the material into the anchor trenches using ground pegs inserted through the overlaps. The overlaps were jointed using stainless steel screws at 200 mm centres. Screws were also used to fix the material to the concrete sandbag headwall at start of the ditch. After hydration the anchor trenches were backfilled to prevent water ingress under the CC. 160 m2 of CC13TM were installed in 1 day and provided a much more cost effective solution compared to the alternatives considered.
The contractor was very pleased with the installation and has since used CC on other areas of the scheme.
“The original drainage solution provided a huge logistical headache so changing the design to a Concrete Canvas lined ditch saved a lot of time; I was really impressed with the speed and ease of installation.” Martin Dewsnap, Drainage Foreman, Hochtief (UK) Construction.
The works were carried out by Hochtief for East Sussex County Council.