This website uses cookies to ensure that we give you the best experience on our website.
By continuing to browse the site you are agreeing to our use of cookies. To find out more click here

Weber - Saint-Gobain

A417 Gloucester Bypass

Contractors seeking a lightweight infill for a bridge abutment on a £18 million by-pass scheme identified Leca® lightweight aggregate as the optimum solution for speed and cost.

Click to download the .pdf

Main contractor Norwest Holst Construction Limited used some 840m3 of Leca® expanded clay aggregate to provide the infill behind sheet piling for the northerly abutment of the twin span Castlemeads Bridge which carries the new A417 Gloucester South West by-pass over the River Severn.

Initially, polystyrene-based fill had been considered for the project but in a value engineering review maxit Leca® emerged as the preferred option, both for cost effectiveness and convenience. The material can be fully submerged and is free-draining, making it ideal for applications adjacent to watercourses.

The sheet piles were retained using tie rods, which were installed in perforated ducts to protect the rods and assist drainage. Leca® in 10-20mm rounded pellets was then tipped in 60m3 loads prior to compacting using traditional infill methods.

A spokesman for Norwest explained: "Earlier in the project we used polystyrene but it is difficult to handle and needs protection from contaminants such as diesel. A value engineering exercise showed us that using Leca® made commercial sense because it provides a quicker and more cost-effective solution."

Leca® is approved for both general fill and structural backfill applications by the Highway Agency.