maxit LWA Geotechnical Fill
Civil Engineering
L l a n d a rc y L a g o o n D ra i n a g e C h a l l e n ge m a x i t Prov i d e s L i g ht we i g ht D ra i n a g e Fill Contractors seeking a solution to providing a lightweight drainage system for a waterlogged peat bog specified maxit LWA – lightweight aggregate – to prevent sinkage and ensure effective drain off. Site owner, multi-national oil company bp, contracted Andrew Scott Ltd, of Margam, Port Talbot, to construct the new surface water drain and interceptor at nearby Llandarcy to replace an old, silted V-ditch within its refinery site.
Because traditional materials would have been to heavy and would sink into the bog, an all-round lightweight solution was needed in order to ensure the drain run and interceptor would work effectively, avoiding backflow problems. Working to a design by URS, of Bristol, Andrew Scot Ltd installed 315 linear metres of half-slotted HDPE drainage pipe backfilled with some 240m 3 of maxit LWA and topped with 300mm of mushroom compost. By using 4-10mm maxit LWA rounded granules as an infill, the contractors were able to surround the
maxit Building Products Ltd. The Heath, Runcorn Cheshire WA7 4QX Tel.: +44 (0)1928 515656 Fax: +44 (0)1928 576792 Web: www.maxit-uk.co.uk Email: sales@maxit-uk.co.uk
pipelines without any damage and substantially reduce the likelihood of any settlement, which was a major risk had traditional heavy pea gravel been used. Use of the lightweight fill also meant that adjusting the levels of the pipe during installation was much easier than it would have been using heavy aggregates and because the surface water drain used was half perforated to act as a filter drain, the system also benefited from the free-drainage properties of maxit LWA.