Sherbourne Footbridge comprises both post-tensioned and traditionally reinforced concrete elements and spans the River Irwell in Salford.
Extensive testing of the post-tensioned beams and pier structures, including chloride profiling, carbonation depth analysis and half-cell potential mapping, revealed significant corrosion damage and areas at high risk of future deterioration. Particular care was required to avoid any damage to post tensioning tendons during either investigation or treatment works.
CPT designed a DuoGuard™ Hybrid Anode™ system to halt on-going corrosion and prevent further damage. In addition, concrete repairs and anti-carbonation coating works were carried out in accordance with BS EN1504.
Due to the possibility of hydrogen embrittlement of the tendons, the impressed current phase of the hybrid treatment was closely monitored and controlled. CPT also supplied a bespoke monitoring system, allowing the performance of the corrosion control system to all twelve beams to be individually checked and supervised. This project was awarded second place in the Asset Protection and Repair category at the prestigious Concrete Society awards.