RM Watson was engaged by Accor Hotels to upgrade the facade of the Manly Pacific Hotel following an extensive internal refurbishment of the iconic beach front location.
Preliminary survey and investigation work upon commencement of the project, established that concrete spalling across the façade was the result of corroded post tension cables and anchorages rather than traditional reinforcing steel. As is common with remedial projects, RM Watson has had to revise the original concrete repair methodology following the commencement of works on site to account for this discovery.
Due mainly to issues of insufficient cover and water run-off from balconies in the area of anchorage components, levels of deterioration of the post tension live anchorages varied from relatively mild to almost complete consumption of strands outside the anchorage.
Treatment of post tension anchorages was determined on a case-by-case basis after careful removal of cover mortar to determine extent of corrosion and condition of grouting of the tendons. Final repairs carried out varied from minor epoxy mortar repairs to remediate areas of minor corrosion. To a full epoxy-based truncation of up to 1200mm of tendon for areas of significant grout and section loss. Further carbon fibre strengthening was also added to slabs requiring truncation.
One of the most important considerations when delivering post tension slab repair projects is avoiding any damage to the already corroded anchorages and tendons. Traditional mechanical removal of corrosion usually results in a loss of steel section which is critical to avoid in repairs of this type. The option for abrasive or high pressure water blasting was not an option at this site due to the close proximity to Manly Beach. To address this, RM Watson’s project delivery team sourced a portable high intensity laser as an alternative method to prepare the anchorages prior to patching. The system uses high use intensity laser pulses to remove mortar and corrosion build up without damaging the tendons or anchors. The system achieves the same results as traditional methods without the associated risks of damage or environmental contamination.
In addition to the delivery of significant structural concrete repairs, the RM Watson team also delivered the following remedial services across the project:
Given the recently completed internal refurbishments, the Manly Pacific team required the hotel to remain fully operational while the façade works were occurring. RM Watson worked closely with the building management team to programme works around the hotel’s function schedule ensuring key scope items were completed and access systems disestablished prior to guest arrival. Thorough pre-project planning and close consultation with building management saw RMW achieve practical completion ahead of the busy Christmas period, enabling the hotel team to book out the newly refreshed site.
For more information regarding the above works or if you have a similar project in mind contact the RM Watson team here.
