The Lee tunnel in Beckton (London), a MVB joint venture (Morgan Sindall/Vinci Grand Projets and Bachy Soletanche), is the first Steel Fibre Reinforced Concrete (SFRC) tunnel ever to be nominated and to win the Concrete Society Award  in 48 years of the awards. The project comprises five shafts, with the diaphragm walls the deepest recently undertaken in the UK at 90m. A 7m diameter 7 km-long tunnel connects the shafts. The innovative Dramix® 5D Steel Fibre Reinforced Concrete for the slip formed tunnel lining took 18 months to develop, resulting in the use of a steel fibre reinforced self-compacting concrete. All 5 shafts were also designed and constructed using this innovative slip formed type of shaft construction. This allowed for a faster and safer construction process.

The Dramix® 5D steel fibres provided excellent bending hardening properties to the concrete section, thanks to the high ductility wire, ultra-high tensile strength and perfectly shaped hooks.

The designer (UnPS) and MVB JV decided to replace the traditional reinforcement with steel fibres, about 17000 tons of rebar was replaced with >2000 tons of the Dramix® 5D steel fibres.

In this way they eliminated the very large and difficult logistical challenge that would have been placed before the contractors’ underground team.

This game-changing Dramix® 5D series provides designers with new opportunities to design steel fibre concrete structures for both underground and surface works and enables contractors to build faster and safer solutions. For further information please read the press release and visit www.bm-underground.com. 48/16.