Corrosion Protection of Inovyn Brine Settlement Tank
Inovyn is at the heart of Europe’s chemical industry. 2.5 million tonnes of salt are extracted from the Holford Brinefield at their Northwich site every year and the plant is an important supplier of raw materials to the chemical industry in Cheshire and the North West of England. As part of their on-going investment in the Northwich brine plant, Inovyn recently commissioned extensive corrosion protection and refurbishment works to the reinforced concrete supporting structure of a settlement tank.
The reinforced concrete plinths supporting the settlement tank were suffering from extensive cracking and spalling due to chloride induced corrosion. As part of the refurbishment process, all cracked and delaminated concrete was broken out and repaired using a BS EN 1504 compliant mortar. Due to elevated chloride levels in the retained concrete there was a high risk of further spalling unless measures were taken to control corrosion of the steel reinforcement.
Effective corrosion protection with DuoGuardTM
CPT’s DuoGuard corrosion protection system was chosen due to its long track record in protecting reinforced concrete structures in aggressive environments. Additional benefits include a low maintenance requirement and performance measuring capability.
DuoGuard is a two stage treatment whereby galvanic anodes are temporarily wired up to an external power source for an impressed current phase. After this typically 7 day phase, the power source is disconnected and the same anodes are left in place to provide long term sacrificial anode protection to the steel reinforcement. Phase 1 brings great benefit in terms of halting aggressive corrosion. Phase 2 maintains steel passivity.
Following installation at the Inovyn site, checks were made to ensure that no anodic sites, indicative of corrosion, were identifiable on the reinforcement within the treatment area. The only anodic sites should be at DuoGuard locations. This procedure demonstrates both the efficacy of the system and acts as a QA check on the installation.
DuoGuard is the perfect solution for controlling corrosion in all manner of reinforced concrete structures, including bridges, car parks, jetties and commercial buildings.