AIRFIRST PTY LTD ABN QBCC ELECTRICAL CONTRACTOR 48744

Transcription

1 AIRFIRST PTY LTD ABN QBCC ELECTRICAL CONTRACTOR 48744

2 Woolloongabba Telephone Exchange, a 15 storey commercial building, is located on the corner of Main and Linton Streets, Kangaroo Point, Brisbane. The building was constructed in In 2013 a condition assessment of the building s façade carried out by Brewster Murray Pty Ltd, found significant degradation of the building s precast panels and concrete in situ walls due to weathering such that pieces of concrete and some elements of the building had become dislodged and fallen off. The inset photographs show the condition of the building which posed significant maintenance and public safety issues. Their recommendation was that urgent steps be taken to carry out rectification works.

3 For over 10 years we have successfully carried out both large and small scale works at Telstra assets. These works have mainly comprised air conditioning and duct upgrades, electrical switchboard upgrades, cabling and controls, standby generator plant replacements, battery and rack installations and building works of a general nature. The requirements of this project were outside the scope of our normal area of expertise and its criticality meant ensuring we partnered with the right people to achieve the best possible outcome for our customer. We engaged the services of Paul Sandeford of GHD, a Principal Engineer for their Materials Technology Group in a consulting capacity and Freyssinet Australia Pty Ltd, a design and contracting company specialising in structural and remedial works, to partner us in completing this project. Freyssinet have been responsible for undertaking building and façade rectification works at some of Brisbane s best known land marks such as Brisbane City Magistrates Court, Anzac Square, Suncorp Plaza, MLC Centre and Brisbane City Hall.

4 In general terms the works involved: Maintaining the operation and security of the Exchange at all times. Erection of various gantries to ensure public safety. The gantries were installed and dismantled progressively as the façade rectification moved around the building. Replacing sealant (caulking) to all precast panels, and the perimeter of all window, louvre and door openings. Concrete cracks and spalls rectification including cutting back the extremities of repair locations, demolishing cracked concrete areas, cleaning, priming and treating corroded steel. Window and louvre flashing rectification including provision of anodised aluminium flashing where missing or requiring replacement. Coating rectification work including removal of existing coatings by three stage cleaning to ensure no residues prior to painting. Coating application work including application of a prime sealer to concrete surfaces, followed by the application of two coats weatherproofing anti-carbonation protective coating.

5 As a construction work site, access needed to be limited to ensure all injury risk was mitigated, whilst not impeding the normal day to day operations of the building. Site management and integrity was maintained by the installation of key personnel: Graeme King and Matt Downs of Airfirst Pty Ltd Paul Sandeford and Glen Edwards of GHD Pty Ltd Scott Wallbank and Dave Dare of Freyssinet Australia Pty Ltd Simultaneously, internal degradation rectification works were carried out including internal fire mains diversion from the basement switch room, structural steel work support to the western fire stairs, painting of the fire stairwell, steel beam and concrete repairs to the cooling tower and landing divider wall section, demolition of the landing block work panels and reinstatement using lightweight panels. All works have been completed with minimal impact and disturbance to the building occupants.

6 Various gantries were erected in order to ensure public safety which were installed and dismantled progressively as the façade rectification moved around the building. All installation was supervised with the support of stop/go personnel to direct pedestrians and vehicular traffic. Security lighting was installed under pedestrian walkways and around the work site for security and safe passage of foot traffic. Access to the façade was via a combination of mast climbers for the main tower structure and either swing stages or fixed scaffolding for the front three level sections. The mast climbers provided for a good level of encapsulation during the repairs and rope access used to identify and remove large spalls prior to mast climber and scaffold installation to ensure the safety of workers. To avoid traffic congestion into the building, the rear car park was utilised as a construction facilities and storage area. Access to neighbouring properties was protected at all times.

7 Below is a comparison between the original tender document, detailing quantities as specified in the brief and actual quantities to date, as per the latent conditions found as the works progressed: 2 FAÇADE REPAIRS & PROTECTION COATING UNIT QTY ACTUAL 2.1 Crack Repair (Item 1a/1b) Lm Concrete Repair In-situ (Item 1c/1d) No Concrete Repair Precast (Item 1c/1d) No Ferrule Plugs (Item 1e) No Rusted Surfaces (Item 1f) No Holes in Concrete (Item 1g) No New Render to Wall (Item 1h) No Loose Louvres (Item 2a) No As Above, Replace Missing (Item 2b) No Perim Jts Louvres/Frames (Item 2c) No Window Gaskets (Item 2d) No Fix Window Panels (Item 2e) No Replace Window/Louvre Set (Item 2f) No Joint Sealants (Item 3a) Lm Roof Level Repairs Item Façade Coatings Item 1 1

8 The superior standard of the finished works has highlighted other areas requiring attention. The ground floor signage is in need of replacement, hazard strips require repainting, the front entrance gardens require replanting and mulching, the loading dock ceiling/awning requires repair and the old roof top loading bay walls are in need of concrete repair and paint. We took it upon ourselves to carry out some minor beautification works at our own cost, to provide a form of value add to the project. Although they are of minimal monetary value, unrectified they would have detracted from the end result: clean up and disposal of old roof top steel conduit, brackets and rubbish, cable tie and support existing Telstra radio coax cable removal of smoker s buckets and disposal of old bike racks cleaning of front entrance Terrazzo tiles cleaning of Linton Street footpath repainting No Parking on the Linton Street roller doors replacement of loading dock awning lights; and repainting of three fire exit doors, front entrance seat, garden edge/planters and copper drain pipe.

9 Some interesting facts relating to the scale of the concrete repairs: In summary, we are proud to say we have successfully delivered a superior quality product to our customer, safely without incident. We are thankful for the opportunity to expand our skills and portfolio of works.