The 1914 road bridge at Farcet near Peterborough has survived two world wars, but heavy agricultural traffic and general wear and tear forced a series of strengthening works. The bridge takes traffic over the river Nene, where swans and fish exemplify the rich wildlife and underline the need for careful management of any works. RHINOCEROS were commissioned by Cambridgeshire County Council to strengthen and refurbish the bridge, including rebuilding retaining walls using Staffordshire Blue engineering bricks and over 1km of repointing on existing brickwork.
5 steel beams support the road, and these were found to be suffering from corrosion. Cracks were found in 2 of the beams, and were repaired by grinding out and re-welding before re-concreting. Concrete retaining walls and beam encasements were also degrading, and concrete repair was required.
After unsound material had been removed, RHINOCEROS brought in concrete specialists GSSL to dry spray Gunite, using a proprietary mix of SIKA 133. The beams were pre-shuttered by RHINOCEROS after material breakout, shotblasting and priming. All surfaces were pre-wetted, then after concrete spraying surfaces were cut back to a wood float finish, and covered with light plastic and allowed to set for 3 days.
Retaining walls on the river approaches to the bridge were repaired by replacing large sections of crumbling brick with new Staffordshire Blue engineering bricks, and expansion joints were cut in. Repointing included both under-bridge areas and external-facing walls.
