Concrete Magazine publishes 15 years of DuoGuard monitoring data

Long-term monitoring of innovative corrosion control system yields fascinating results – by David Bewley and Christian Stone from CPT

Whiteadder Bridge spans the Whiteadder River in Berwick-upon-Tweed, Northumberland. Inspections had revealed substantial areas of spalling/loose concrete and salt deposits in the main substructure. Concrete Preservation Technologies proposed an innovative corrosion control solution and in 2007 a DuoGuard™ 500 hybrid anode system was installed to stop the corrosion and prevent further damage to the contaminated piers and abutments.

On completion of the works the bridge was chosen for intensive monitoring for three main reasons. The visible cracking and delamination of the concrete cover, the high chloride contamination readings by weight of cement and the fact that Whiteadder River was subject to periodic flooding meaning that the bridge piers were often subject to extreme wet–dry cycling.

15 years on, and after continuous monitoring, the data gathered provides a fascinating insight into the workings of the world’s first hybrid anode cathodic protection (CP) system.