Tickton Flyover, which carries a vital ‘A’ road over the River Hull in East Riding of Yorkshire, was found to be at risk of corrosion due to signs of chloride in its concrete columns and beams. A proven solution was required to prevent corrosion forming on the steel rebar and maintain the flyover’s structural integrity. It led to the specification of Sika Galvashield CC100 anodes. The cylindrical anodes are quickly and easily installed into concrete to control corrosion activity and prevent the new formation of corrosion sites on reinforced concrete structures.

Working on behalf of East Riding of Yorkshire Council, main contractors, NMCN Plc, selected Churchman, Fenner and Brown to install the Sika Galvashield CC100 anode system. Refurbishment work began in June 2018 and required using scaffolding erected upon a pontoon to reach repair areas due to the flyover being located over a river. For the installation process, contractors core-drilled the flyover’s damaged supporting columns and beams before inserting the anodes. Available in a range of sizes, the anodes comprise a specially-formulated precast cementitious mortar which surrounds and activates its sacrificial core. The zinc anode – when correctly installed and connected – corrodes preferentially to the surrounding steel, providing galvanic corrosion prevention and control to the adjacent reinforcement.

Nearly 1,000 anodes were used in the flyover’s repair. These were tied at intervals to the reinforcement and charged using a Sika Galvashield Anode Connection Kit. Sika Galvashield Embedding Mortar provided the drill holes’ repair.

Iain McMillan, Contracts Supervisor at Churchman Fenner and Brown, said: “The Sika Galvashield CC100 system proved incredibly effective in the refurbishment of Tickton Flyover. The concrete surrounding the steel rebar proved a challenge to penetrate due to its depth and thickness, but the anodes themselves were quick and simple to attach. The solution enabled us to complete the refurbishment project ahead of deadline.”

Repairs using the Sika Galvashield CC100 system were completed in September 2018. In providing long-term protection against potential damage caused by corrosion, the anodes significantly reduce the risk of future repairs, making it a cost-effective, as well as a reliable solution. Sika Galvashield CC100 anodes might be small, but thanks to the system’s ingenious technology, they prove mightily effective in protecting structures such as bridges, car parks and tunnels against the perils associated with chloride and carbon-induced corrosion.

Denise Maguire   Editor of Irish Construction Industry Magazine