Heritage Building Balcony Strengthening - September 2006
South Avenue, Double Bay
Download September 2006 newsletter in PDF form
This three storey heritage building was constructed in 1932 and contains curved concrete balconies on the front and rear elevations.
Strata Engineering Solutions were contacted to attend site in the aftermath of a balcony collapse to one of the Units. Fortunately, nobody was injured as a result of the collapse.
Investigations were carried out and it was determined that the cause of the collapse was attributable to a combination of factors which included spalling concrete, crack propagation and the non-existence of top steel primary reinforcement.
The Owners Corporation responded immediately to the situation by ordering an investigation into the condition of the remaining balconies to ensure the safety of residents and to determine what remedial action might be required.
Structural Systems carried out the investigatory work which revealed that minimal concrete cover was causing corrosion to the band beam reinforcement and that none of the balconies contained top steel reinforcement. This combination revealed a catastrophe waiting to happen!
Given the nature of the existing construction we were required to undertake extensive strengthening works to ensure the safety and longevity of the balconies. The other option was to demolish and re-construct the balconies which would have been disruptive and costly to the Owners.
The rectification method involved the replacement of the corroded reinforcement in the band beam and conventional patch repairs to the slab soffit. Carbon fibre reinforcement was bonded to the top surface of the slab to provide adequate strength to the cantilevered section of the slab.
Membrane coatings were then applied to the top and bottom of the slab to provide further protection against the elements.
Structural Systems are nearing the very successful completion of this project whereby the balconies on this heritage building will be structurally sound for many years to come.
This project was definitely an ‘eye opener’ for all involved.
Alldis & Cox (Coogee) Pty Ltd, the Owners Corporation and Structural Systems have done a great job in responding to the needs of the building. Well done to all.