A popular topic among building engineers, who consult on the Gold Coast, is Concrete Cancer.
In a recently completed project report, BRS Building Rectification Services reviews, ‘Ocean Sound’, a well-positioned property situated within the iconic Surfers Paradise, on the Gold Coast.
Ocean Sound was built in the 1960s, in a period when the Gold Coast grew from a small town, transitioning over time, into the thriving tourist hub it is today.
Built with a north/south orientation, the front of the structure faces south. The building consists of a three (3) storey cavity brick and suspended concrete floor residential unit complex. Internally housing six (6) units with four (4) ground-level garages, as well as an attached common laundry area. Ocean Sound’s metal roof is divided into two by the central location of the entry staircase, servicing all three levels.
Upon review, Ocean Sound had a number of areas which needed attention. As a result of the buildings close proximity to the ocean and breaking surf, the effects of Concrete Cancer, e.g. fretting, cracking and spalling, had caused many of the building’s surfaces; various walls, balconies and exteriors to corrode.
The Consulting Engineer on this project noted that;
“The external inspection of the building identified areas where corrosion of the embedded steel reinforcement has caused cracking and dislodgement of the concrete cover”.
BRS Building Rectification Services, were able to quickly identify the problem areas, addressing the floor slabs first and applying the appropriate concrete cancer repair techniques for that stage of the project. In this instance exhuming the corroding steel reinforcement, treating the rusting steel bars, and then reinstate the edge of the concrete floors.
With ten key areas to resolve, BRS Building Rectification Services worked through each section covering, the buildings columns, slabs edges and balconies, rectifying the roof, as well as reinstating new balustrading, which met certification standards.
A sampled scope of works for this project was:
Site set up and establishment of all Workplace Health and Safety requirements for Access requirements, OH&S items, Exclusion Zones, Signage and Work Site
− Install temporary fencing for exclusion zones and Erect Scaffolding.
− Install Acro-Props to support balconies for the duration of repairs
− Remove and dispose of existing balustrade
− Disconnect downpipe and retain for later reinstallation
− Mechanically demolish spalled concrete within the area of works deemed unsafe, dispose of rubble from the site
− Treatment of Sound Steel Reinforcing; this includes the cleaning, preparation and coating of the exposed steel reinforcement with the use of Zincrich Primers
− Replacement of un-sound steel reinforcing; this includes the removal of the corroded steel that is deemed to be structurally unsound and welding/tying new reinforcing steel, back into place (only where required)
− Form up areas of repairs, including forming up isolated column to pour new, oversize column.
− Pour repairs using 55mpa concrete. Remove formwork once cured
− Fairing coats to used to finish repairs where required
− Paint areas of repair only, colour to match existing as close as possible
− Remove Props, scaffolding and fencing and demobilize from site
− Builders general clean of immediate work site on completion
For more information about this project or Concrete Cancer in general, contact us today!