Because of the need to keep Auckland City traffic flowing during the day, CSI sometimes needs to work overnight on upgrades and maintenance of the city’s infrastructure.
So it was with this busy Auckland bridge in the city.
CSI needed to work after hours and perform controlled breakouts at specified locations to reveal the extent of corrosion in existing reinforcement. Scanners were used to identify the location of the steel for these breakouts.
In situ carbonation testing was to be carried out in the proximity of each breakout location to establish the degree of carbonation within the concrete; which in turn, can be an indication of potential corrosion of reinforcing bars.
CSI was also asked to conduct chloride contamination tests. Chloride can potentially attack the passive layer of reinforcement if Oxygen and Water are present.
CSI followed up these tests by taking core samples to check concrete composition back at the lab.
Due to the location, there were some challenges to ensure the work was completed to the highest environmental standards and controlled all slurry, dust and other waste material. CSI also had to prevent anything falling on the motorway below and repair breakouts to the highest possible standard.