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Printed in Australian Concrete Construction, April 2001, page 30 The concrete jungle is of course the formwork that not only represents expense, but also impedes access to follow on trades.
The commercial building being constructed for MB Developments, on the corner of Ricketts and Blackburn Roads, Glen Waverley, 20kms southeast of Melbourne's CBD is an excellent example of avoiding the concrete jungle. It is being constructed under the tightest of timing. The building site is unobstructed, except for a crane to lift precast components and position them into place. The developer MB Developments is also a builder, and has extensive experience in the use of precast elements. A feature of this development that strikes the visitor is the degree to which precast techniques have been used, down to stairways and landings.
Barry Baker, Managing Director of MB Development, is experienced in the use of hollowcore plank construction to meet the demanding requirements of speed of erection and flexibility in future building usage. One of his most recent developments, this large modern office facility comprises a five floor structure of total area 10,000 square metres, including two underground parking levels. The structural design is by Bruce Gardner and Associates, and the precast products including the hollowcore planks, columns, beams, corbels, panels, spandrels, and even stairways and landings were supplied by Hollow Core Concrete of Laverton North, Victoria.
Once ground preparation had been completed in December, the construction work from then on took place at breakneck speed, with the building shell being completed by the end of February, 2001. Construction speed is a feature of a well organised precast project. It certainly applied here. Hollowcore also answered the need for cost reduction by saving concrete, eliminating formwork and scaffolding, and permitting early access to multiple follow on trades. Flexibility is a feature as well, as the hollowcore planks can be easily drilled for pipework, electrical, and HVAC ducting. The spans that can be used exceed 12 metres, ideal for open office space and parking areas.
The construction method is economical in terms of material and labour costs. Savings relative to insitu concrete slabs vary depending on the building design and function. As an estimate, savings can be as high as 15 per cent compared to insitu slabs. Overall building cost can therefore be reduced in the region of 3 per cent, or more.
The cost savings are matched by time savings, where Hollowcore floors really score. Interruptions by wet weather do not matter anywhere near the extent that wet weather interferes with conventional poured-in-place concrete floor slabs. |