Post-tensioned band beams as moment resisting frames under earthquake loading: A state-of-the-art review

Post-tensioned concrete wide-band beams are used increasingly as a common floor construction method in Australia.More recently, there has been a growing need for the floor system to contribute to the seismic resistance of the building as a moment frame. However, relatively little is known about the performance of wide post-tensioned beams under this type of loading. This paper reviews the current state of knowledge in this area, and assesses several current building design codes in terms of their relevance to this type of construction. Current research shows the potential to achieve adequate drift and energy dissipation in areas of low to moderate seismicity, but research is very limited, particularly for post-tensioned wide beams. While AS3600-2009 does not contain any width limitations on beams resisting earthquake loads, other codes do limit this width for certain levels of ductility. However, these design codes focus on narrow beams, and the beam width restrictions are generally based on limited research data. Construction techniques and seismicity levels vary significantly for different countries and this affects different design codes. Therefore, the relevance and applicability of several code design and detailing requirements in relation to beam widths and detailing typically used in Australia are questionable.