Remedial Technology leads the refurbishment project of a major harbour-side car park in Kirribilli
Updated: Oct 19, 2021
Remedial Technology was engaged to manage the refurbishment work of a deteriorating 1960s car park structure at Kirribilli in NSW. The work involved a condition assessment of the structure, preparation of a repair specification, and provision technical support and project management services for the rectification work.
The two-level car park structure, consisting of ground floor parking and a 600 m2 top deck, suffered from significant concrete cracking and spalling problems. The condition assessment work identified that the main causes of concrete deterioration were due to concrete carbonation and low concrete cover to the reinforcing bars at the soffit. The car park deck which was covered with asphalt and pavers had allowed water ingress through the cracks and this accelerated the corrosion problems at the soffit.
Following a detailed testing and concrete assessment, a pilot repair application was performed for a selected area of the soffit and deck of the carpark. The aim of the pilot project was to confirm the selected methodology and validate the effectiveness of the repair materials.
The method of concrete repair included breakout of the concrete behind the reinforcement using hydro-demolition, cleaning of the steel to bright metal condition using grit blasting, and the application of high resistivity polymer modified repair mortar by wet spray application. Approximately 24,000 litres of repair mortar were applied to restore the concrete to its original profile and to apply an additional 12 mm of repair mortar to provide additional cover to the embedded rebar. Anti-carbonation and anti-chloride protective coatings were applied over the entire concrete soffit area for additional corrosion protection.
For one large beam facing the ocean, Smart Zinc 130 Edge galvanic anodes were installed to provide corrosion protection to embedded rebar.
At the top deck, following removal of the pavers and asphalt, repair work was carried out and the concrete surface was prepared by grit blasting and a trafficable membrane was applied on the entire surface. Three planter boxes located at the deck were also repaired and a special planter box membrane system was installed.
The duration of the project was approximately seven months. Some of the challenges encountered during the work included noise management generated by the hydro-demolition of the concrete, and complications related to work scheduling due to COVID-19 restrictions.
Remedial Technology Pty Ltd was involved in the condition assessment of the structure, preparation of the technical specification, and leading the tendering process and project management for the work. The main contractor for the project was Duratec Limited.