WOTTON BRIDGE

Wotton Bridge is a Network Rail structure carrying the Bristol-Birmingham line over a single lane country road in Gloucestershire. The five-ring red brick segmental arch with solid brick abutments showed a plug of brickwork active under rail load during a recent refurbishment. The arch barrel had been grouted and pinned, giving no visible improvement in stiffness in one section. Balfour Beatty and Tony Gee brought Tempo-PCE on board to carry out strengthening injection due to our experience with Normet UK’s ultrafine grout, a specialist cementitious grout with latex. The crown was drilled and injected, with clay used to close any material running out through missing mortar. The strengthening, in combination with brick re-casing, significantly stiffened the structure and deflection settled to about 0.90mm, leaving Network Rail  “very impressed”.