COLUMN WRAPPING with reinforcing aramid fibres will be used for the first time in the UK on an M11 overbridge, the Highways Agency confirmed this week.
Specialist contractor Balvac Whiteley Moran is awaiting formal approval for its proposal to reinforce four circular columns on the Coopers Sale overbridge south of Junction 8 with a wrap of Dupont's Kevlar fabric.
The operation will enhance the structure's resistance to HGV impact. Two years ago the Agency carried out a programme of comparative column wrapping trials featuring Kevlar, carbon fibre and glass fibre systems (NCE 20 August 1998).
Kevlar was commended for its ease of handling but an Agency spokesman said all three options were acceptable.
'It's up to the contractor to select the system that he prefers, ' he added. Balvac regional manager Richard Bailey said previous experience with applying Kevlar to a concrete cooling tower was one of the reasons for selecting the system for Coopers Sale.
Cost of the strengthening operation is estimated at over £600,000. Structural engineer is TB Kennedy & Donkin, Kevlar supplier is Feb-MBT.