Completed Project: Remedial Concrete Spalling & Associated Works
SCOPE OF WORK
The reason for the carrying out the scope of works was due to severe concrete spalling in areas as a result of salt driven winds from the nearby harbour. Other project works included for the erection of scaffolding, tiger tailing to electrical cables, masonry demolition works, brick reinforcing works (with the Helifix system), waterproofing & tiling works, rendering work, construction of new balustrade works, glazing works and painting works.
The project was undertaken on a live unit block in Sydney. As the project was to be completed in a live building we were required to implement & maintain good OHS & Environmental work practices.
Each balcony on the building was required to have works completed to them, including for demolition, remedial (repairs to concrete spalling) and construction works completed. Protection access tower scaffolding was erected in front of each balcony stack to provide safe access without disturbing the residents in each unit. The scaffold towers were wrapped in chain wire mesh & shade cloth to ensure the security of the building was maintained for the duration of the works.
All works were completed externally hence we did not require internal access to the units for any works on the project. Murphy’s site manager Sean Bateman did however liaise daily with the residents to ensure they were happy with the progression of works & the harmonious nature in site was maintained.
The erection of the scaffolding not only provided a safe working platform for the works but also ensured the residents were affected minimum by the project.
The project was initiated after a completed diagnostic building report identified that the existing balconies were suffering from concrete spalling. Some of the balconies were so bad that the structural integrity were beginning to fail. The building is located within a couple hundred metres of the Harbour, hence is subject to salt winds. The building being a live residential unit block, it is paramount that the balconies are safe & compliant hence it was essential to complete remedial works immediately.
Upon the completion of the erection of the scaffold towers, the brick balustrades to each affected balconies were deconstructed & removed from site. This was a ‘Hold Point’ in where the superintendent identified & marked out the spalling areas to be rectified.
Once identified, we commenced with the demolition and removal of the defective concrete. The concrete was removed with jackhammers & grinders as required. We programmed the demolition works in consultation with the client so that these noisy works were completed at appropriate convenient times.
The project being a remediation of concrete spalling meant that ‘Hold Points’ and inspections throughout were essential in ensuring the works were completed in accordance with the manufactures requirements, engineers instructions & relevant Australian Standards.
All concrete remedial works were programmed & executed with the appropriate ‘Hold Points’ to ensure works were completed to the highest degree of quality.
Upon the completion of the removal of the concrete, the steel reinforcement was treated as required in accordance with the requirements of the supervising engineer for the project. Where required the steel reinforcement was replaced with new galvanised bars. This was then another ‘Hold Point’ on the project before the reinstatement of the new protective concrete/repair mortar.
The new concrete repair works were finished neatly & flush with the adjacent concrete surfaces so that the evidence of the concrete spalling repair works was minimal. This again was a ‘Hold Point’ for the inspecting engineer so it could be verified that the completed repair works were to high quality & client requirements.
Upon the completion of the repairs to the concrete spalling works the rendering & painting works were completed. Other project works were carried out by our trade qualified employees such as brickwork & structural upgrading of the blade brick walls with Helifix ties.
The final work on the project was the supply & installation of new aluminium balustrades with glass inserts. The new balustrades were measured onsite & fabricated off site as appropriate and powdercoated. The aluminium balustrades were installed in sections & the new glazing placed & sealed.