A change of scene: How the canterbury earthquake sequence led to a departure from concrete technologies

Nature can be brutally honest and will, over time, expose even the slightest weakness in manmade systems and constructions.  This certainly became evident in the aftermath of a series of unexpected earthquakes shook Christchurch during 2010-11. The New Zealand concrete industry, from research and development through to manufacture and construction, had gained international respect and contributed significantly to the country’s development, particularly in the Canterbury region.  Structural innovation, developed through partnerships between academic and commercial organisations, helped make concrete the material of choice and throughout the 20th century and into the next, architects, engineers and builders utilised these technologies to redevelop and expand the city.  Not only are the raw materials available in abundance but the finished product fashioned into buildings responds well to local conditions.  Indeed, the city acquired a well-deserved reputation for the quality of its concrete buildings. The first half of the paper traces through the key moments of innovation during this period. Following the earthquakes, when many shortcomings in the design, construction and maintenance of buildings were revealed, there have been changes in standards and codes aimed at improving their performance in the future.  Alongside this, the use of concrete for structural and architectural purposes has been marginalised and largely relegated to utilitarian floor slabs in otherwise steel, aluminium and glass structures.  The paper discusses reasons for this sharp retreat from local and well developed technologies.  These include people’s changed perceptions of concrete, shaped by two key building failures; the availability of steel in the marketplace; and widespread departure from an architecture that responds to local conditions to one that relates to global trends.  The paper adopts a critical view of this departure, arguing that a response through further innovations would be more appropriate.