Corrosion of steel reinforcement is the most serious and common deterioration problem affecting reinforced concrete bridges in New Zealand.
Remedial treatments for concrete damaged by corroding reinforcement include electrochemical treatments (cathodic protection, realkalisation and chloride extraction), which potentially offer a permanent treatment, and patch repair, which is cheaper but does not always prevent future deterioration.
This research, carried out in 2002–2003, complements a 2001–2002 review of electrochemical treatments. It describes the features of current patch repair techniques, and uses New Zealand and Australian experience to compare the likely long-term performance and costs of both types of treatment for New Zealand bridges. This will enable New Zealand bridge asset managers to select appropriate repair technologies to suit the needs and circumstances of individual structures.
The research indicates that immediate costs of patch repair will almost always be lower than the costs of installing electrochemical treatments. Life-cycle costs will also usually be lower for patch repairs, but can favour electrochemical treatments under certain circumstances.
Keywords: bridges, cathodic protection, chloride extraction, concrete, concrete repair, corrosion, costs, extrochemical treatments, New Zealand, patch repair, reinforcement corrosion, roads, traffic