Image courtesy of Transport for Scotland.
Saint-Gobain in Scotland has provided its expertise and materials to the construction of the new Queensferry Crossing, the 2.7 km long bridge linking Edinburgh and Fife.
The Crossing Bridge is the longest three-tower, cable-stayed bridge in the world and also the largest to feature cables which cross mid-span.
Saint-Gobain-owned Leca UK, which specialises in the production of Leca® expanded clay aggregates, has supplied 5500m3 (worth £251K) of its light-weight aggregate Leca® LWA 10-20mmR to be used in the reinforcement of the bridge’s supporting structure on the north side of the A90.
Leca’s work in the area involved supplying the Light Weight Aggregate, which was used to raise part of the existing A90 mainline levels and widening westwards. The traditional solution of direct placing conventional fill materials on the existing A90 and the adjacent ground would have applied additional loads on the soft peat and underlying alluvial materials, resulting in unacceptably large settlements, as well as causing environmental issues.
Leca Lightweight Aggregate’s (LWA) density is around 25% of that of conventional fills, so the team opted for excavating the existing ground to a depth that allowed for replacement and filling up to the new design level. This resulted in a net load of zero being applied to the underlying soft strata, which assured that the post-construction settlement was kept to a minimum and differential settlement issues compensated.
Leca’s LWA brought additional short- and long-term benefits, such as significant time saving in construction duration, which resulted in minimal disruption and delays to existing road users. This came with environmental benefits, as there was reduced congestion and vehicle emissions.
Frazer, a specialist distributor of civils and utility products in the UK, supplied £1m worth of civil engineering products, such as Twinwall pipes and fittings, as well as manhole covers and frames, to be used in new roads giving access to the bridge and the surrounding areas.
Stuart McKill, Sustainable Habitat Leader for Saint-Gobain in Scotland, said: “At Saint-Gobain in Scotland, we’re very honoured to have taken part in such a high-profile project from the Scottish Government, working alongside the team at FCBC, among many others. The new bridge is reshaping the Scottish landscape and we believe it will have a positive impact on the citizens’ lives.”
Leca UK and Frazer are part of Saint-Gobain UK and Ireland, a leader in sustainable habitat. For more information about Saint-Gobain in Scotland, visit www.saint-gobain.scot