Non-Tearing Joints (Slotted Beams)

width=250Tests at the university on a 60-tonne, two-thirds scale model of the lower two storeys of a seven-storey reinforced concrete building have found that creating a slot about three-quarters of the way up a beam / column joint reduces damage to the building and increases performance during an earthquake.

The slotted beam allows the building to flex and prevents the concrete beams from increasing in length, lessening damage to the frame and floors, and resulting in a much safer building. The technique is subtle, inexpensive and simple to incorporate into building designs.

It is anticipated that as an example of damage resistant design using concrete systems the “slotted beam” will be included in the New Zealand Concrete Structures Standard, and utilised in rebuilding Christchurch, as well as the retrofit of existing buildings.


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“This form of system [non-tearing joints / slotted beams] or something like it is what we want to use to rebuild Christchurch.”

DES BULL
HOLMES CONSULTING


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Selected Resources

Title: Development of a non-tearing floor solution for jointed precast frame systems
Author: A. Amaris, S. Pampanin, D.K. Bull & A.J. Carr
Source: 2007 NZSEE Conference.

Title: The development and validation of a non-tearing floor precast concrete structural system for seismic regions.
Author: Amaris, A., Pampanin, P., Bull, D.K. & Carr, A.J.
Source: 2008 NZSEE Conference

Title: Numerical investigations on the seismic response of multi-storey hybrid post-tensioned precast concrete frames with non-tearing floor connections
Author: A. Amaris, S. Pampanin, D.K. Bull & A.J. Carr
Source: 2009 NZSEE Conference

Title: The seismic performance of a non-tearing floor precast concrete structural system
Author: B.J. Leslie, D.K. Bull & S. Pampanin
Source: 2010 NZSEE Conference

Title: Preliminary observations from biaxial testing of a two-storey, two-by-one bay, reinforced concrete slotted beam super assembly
Author: C.A. Muir, S. Pampanin & D.K. Bull
Source: 2012 NZSEE Conference

Title: The development and validation of a non-tearing floor precast concrete structural system for seismic regions.
Author: Leslie, Benjamin John
Source: University of Canterbury. Civil and Natural Resources Engineering - Degree: Master of Engineering