The Rotman School of Management at the University of Toronto (Canada) had outgrown its space over the past decade, resulting in the construction of a new 150,000 m2 building. The building's exterior curtain wall system has incorporated 350+ dark grey precast Ductal® UHPC panels that are just 30 mm thick; varying in size - from 0.5 to 1 m wide x 3.5 to 5.3 m high. In addition to the cladding, over 100 Ductal® UPHC panels (19 mm thick) create an impressive interior wall that nicely compliments the exterior design.
According to the architects, Kuwabara Payne McKenna Blumberg (KPMB), the new building design is a direct expression of Rotman's core mission to promote creativity, innovation, and integrative thinking in 21st century business education. The overall concept advances the school's long-term sustainability and business strategy, and will meet Leadership in Energy and Environmental Design (LEED) Silver requirements.
The choice to use Ductal® UHPC was derived from its ability to achieve the architectural design features and meet structural requirements. The syncopated east façade was made to facilitate the integration of an opaque panel into a high-performance curtain wall. The esthetics of the precast UHPC was paramount in the decision as it provided the subtle matte finish within the colour range desired.
The architect's design criteria was ambitious because the university, preferred a long span façade panel (up to 5.5 m.) that was thin and lightweight with a hard, durable exterior wall surface that would endure for a long time--with little to no visible signs of wear from elemental impacts. UHPC provided a very thin, monolithic-plate, slab-type design with a custom coloured and moulded surface aspect that would essentially ‘plug-and-play' with current curtain wall framing systems, without intermediate jointing.
Collaboration: the key to success
As with most innovative designs, strong collaboration among various key parties is paramount to the success of a new approach. In this case, the precaster (Armtec) was fairly new to UHPC; therefore processes were developed to ensure a quality consistent finish for every panel. Also, because the curtain wall manufacturer had never worked with UHPC panels (inserted into their curtain wall system), the project managers had to co-ordinate the transfer of knowledge and procedures for everyone involved. This ensured that the final product met and exceeded the design and esthetics parameters, which were key requirements by both the architect and owner.