The iconic Telus Sky project in Calgary was awarded an ACI Building Award of Excellence in Concrete by the Alberta Chapter. The biennial ACI Awards recognize outstanding design and construction efforts within Alberta’s concrete industry in five categories, highlighting innovation, creativity and excellence in the use of concrete and concrete products.
The project team for Telus Sky includes Icon West Construction, Glotman Simpson, Inland Concrete, Bjarke Ingels Group and Westbank Projects.
Telus Sky is a twisting and modulating 224m tall concrete tower rising in the heart of downtown Calgary. Designed by renowned architect Bjarke Ingels, it will be the third tallest tower in Calgary and the fourth tallest in Western Canada. The building is the tallest concrete structure in Calgary and will provide the highest residential living in the city.
The tower was developed on a very small lot relative to its size. In order to deliver the required number of parking stalls, the project needed seven underground parking levels. The resulting excavation was the deepest in Calgary’s history, reaching a final depth of 115 feet below grade. The twisting and stepping shape of the tower resulted in walking columns and a unique lateral load resisting system. Transfer beams in the parkade transferred an astonishing 26 million pounds of force onto just four individual columns.
Structural steel sections were embedded within these “super-columns”, however the size requirements for the columns was still enormous. In order to maximize the number of parking stalls adjacent to these columns, the project called for the use of concrete with a compressive strength of 110 MPa: a strength never before achieved in Alberta. The project team successfully designed and placed concrete that reached 110 MPa and beyond. In doing so, they set a record for the strongest commercially produced concrete in Alberta’s history.
In order to successfully produce concrete that would consistently and reliably meet a 110 MPa compressive strength, Inland conducted months of lab trials, experimentation, research and development.
One of the key ingredients to the mix was special cubic-shaped aggregate typically reserved for use in asphalt production. The project needed approximately 1100 cubic metres of the 110 MPa mix, which meant that Inland had to start screening and stockpiling enough of this specialty aggregate well in advance. Inland dedicated a team of quality control specialists to every batch of 110 MPa concrete produced.
