ABSTRACT
Patch repairs are commonly used to restore the concrete profile. For concrete deterioration relating to carbonation, patch repairs can be very effective as the freshly alkaline mortar will restore the passivity to the reinforcement. However, when the corrosion damage is chloride induced significant quantities of contaminated but sound concrete need to be removed. Bridge Advice Note 35 (BA 1990) suggests that areas which show chloride concentrations greater than 0.3% by weight of cement and half-cell potential measurements are higher than −350 mV should be removed. This approach often makes patch repairs uneconomic for chloride contaminated structures (Christodoulou 2008).
