Topflow Steel Fibres

Client London Underground Ltd/Crossrail Contractors Costain/Laing O’Rourke JV Completion May 2016

TOPFLOW STEEL FIBRES

Proven performance BOND STREET TUBE STATION, LONDON W1

The challenge Our solution Results and benefits To connect Crossrail with the A Topflow variant with hook end 1,500m3 of TOPFLOW STEEL London tube system new passenger 0735 steel fibres was designed by FIBRES were successfully supplied foot tunnels were to be the London RMX technical team over a 20 week programme. Tunnel engineered beneath Oxford Street to meet the engineering design invert beds for passenger footways, and Bond Street. To achieve the requirements. The TOPFLOW mix complex internal structures and engineering design the Costain/ contained steel fibres to eliminate trapezoidal escalator barrels Laing O’Rourke JV needed to the need for crack reduction mesh, were constructed quickly and place 1,500m3 of high strength and featured an SF2 consistence efficiently. Budgets reigned in concrete 40 metres below the to self compact and eliminate with TOPFLOW STEEL FIBRES street through the Marylebone Lane the need for noisy compaction yielding a £50/m3 cost saving shaft. Concrete was to be pumped pokers below ground. TheTopflow over site mixed spray concrete up to 180m, often downhill, along mix should pump well over long alternatives. On completion of the a twisting, turning and confined distances and be retarded to give a TOPFLOW pours Senior Tunnel route. Very difficult site access three hour open life, allowing time Engineer, Aled Daviessent, gave his and into the new tunnels meant for pump lines to be moved during congratulations and thanks to the that crack control mesh could not the longest pours. London RMX Team and a referral be stored on site or fixed safely. for TOPFLOW STEEL FIBRES on Speed of placing concrete into the the next tunnel job. variety of structures was required underground and the need to limit noise and dust in the confined workspace were all major issues. Programme and budget overruns from the earlier tunnelling and site mixed spray concrete lining works needed to be brought back on track.

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