Preparation |
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HISLOP, Brad |
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BBSC 341 - Second Semester - 2002 |
Critique / Discussion |
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Drossbach duct system – pre-cast walls The Drossbach system is a method of connection between concrete elements, it uses a steel tube cast into one of the elements which is threaded over a steel bar protruding from the other concrete element. In this studied case the steel tubes were cast into concrete walls which were threaded over Steel bars penetrating the concrete floor. Once the steel rod/bar is inside the steel tube it is filled with a strong grout locking the elements together. The Drossbach duct system has a wide variety of uses as it is mainly used with precast concrete construction. The concrete industry in New Zealand is well developed due to the supply of raw materials and technology throughout the country and thus is known as a world leader. This system can be used in a diverse number of applications because of its ability to be used with precast concrete, this ranges from shopping complexes to motels and hotels and therefore has been used a lot in New Zealand. The Drossbach Duct system allows a jigsaw like structure to be constructed.
Like a jigsaw all the pieces are made previous to construction and all
that is required is to slot them into position. One of the main influences
to developing this jigsaw-like system was to increase the speed of construction,
which along with the simpler structural form lowers the construction cost.
The Drossbach duct system combined with pre-cast concrete construction
has several advantages over alternative constructions for similar buildings.
The strong connections between elements along with the pre-cast units
themselves act as a load bearing system eliminating the need for columns
and other structural forms. Concretes high thermal capacity means its
resistance to fire is high requiring no extra expenses to meet regulations.
This high thermal capacity also helps to provide more consistent temperatures
throughout the year. Concretes high density means it reduces sound transmission
greatly with an STC rating of 52 for the 150mm thick panels used in the
studied case, this is especially important in residential applications
to provide cross talk attenuation. Reinforced pre-cast concrete is a robust
material it can handle wear such as that imposed in commercial and industrial
applications. Its qualities also mean it does not require extra treatment
for weather protection and will remain durable over the life time of the
structure. |
Acknowledgements / References |
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Acknowledgements: All the team at Maycroft construction especially Robbie and Adam. Also to the tutors of BBSc 341. References: “Tilt up construction” (1986) - American concrete institute. |