Description

This Technical Recommendation specifies a laboratory test procedure to enable the seismic performance of external glazing systems to be assessed.

It also specifies an evaluation method that uses the test results to provide the seismic deformations that can be safely sustained by the glazing wall system, if properly installed in a building.

The relationship between computed inter-storey deflections, as calculated during design, and that required during testing of the glass curtain walls, is discussed. It is recognised that many of the glazing failures that have occurred in historic earthquakes may have been the result of poor installation procedures, inadequate attention to detail and the common use of semi-rigid putty and bedding compounds which restrict glass edge movement.

Scope

This Technical Recommendation details how to assess performance of external glazing systems when they are installed on buildings subject to earthquakes. It is essential that laboratory specimens be precisely the same as installed in the field including all weather proofing details, as small differences can significantly influence behaviour. The window size may be reduced for testing purposes but it must be at least half size and the aspect ratio cannot be reduced. Testing has indicated that inclusion of out-of-plane loading on the in-plane loading does not result in a significantly more critical loading case. For glazing systems where this is unlikely to be correct, this recommendation is not applicable.

It is recommended that glazing systems tested and evaluated in accordance with this Technical Recommendation be accepted as achieving under seismic loads the factored inter-storey displacement tested in the laboratory.