Building 2, The Crossing, Highbrook

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Award:  Other Entrants

Project:  Building 2, The Crossing, Highbrook

Entrant:  Busck Prestressed Concrete Ltd

Owner:  Goodman Property Services (NZ) Ltd

Architect:  Jasmax Ltd

Consulting Engineer:  Holmes Consulting Group

Contractor:  Dominion Constructors Ltd

 

The precast panels for Building 2, The Crossing, Highbrook, presented challenges in producing the complex architectural shapes within fine tolerances to interface with the glass cladding system.  These challenges were amplified by the need to produce in an extremely cost effective manner, due to the constraints imposed by the current "super competitive" tender mrket environment. 

Although the shape of the facade appears extremely complex at first glance, Jasmax had designed it to a regular modular pattern, a prerequisite for cost effective precast production.  Our analysis determined that there were three panel type "sets", requiring three panel molds, on which the various modifications within that "set" could be produced.  Rather than building three expensive molds we elected to build one accurate oversize panel configuration, which accepted the three required molds overlaid on each other.  We then reverse cast three 'high' quality concrete casting plugs from the base unit.  Very cost effective.

The contractors panel delivery program vs our production program also had to be taken into account, as the panels cast from the concrete casting plugs required production of the largest units first down to the smallest last - this reduced the need to repair any possible defects on previously cast on surfaces.

So the casting sequence from each plug was size driven, not delivery driven - we had to ensure we had adequate time to meet the site's requirements.

In order to ensure the project met dimensional tolerances our draughtsman completed a full CAD model of the concrete facade.  This CAD model, when approved, was provided to the main contractor to assist with establishing grids for site installation.  Also, the individual panel CAD drawings were the basis for the production of the mold shape formers, these being cut on a CNC Kinetic gas cutting bed.  Finally, our CAD model was provided to the window contractor for his assistance in designing/building the glass facade.

All in all a seamless interface which went extremely well.