Boral has claimed its high-strength concrete, Aspire, was a key factor in the success of Multiplex’s 82-storey tower, The One, completed in Brisbane last year.
The residential tower, housing 467 apartments, at 300 George Street in Queensland’s capital, is the third stage in a new precinct known as the Brisbane Quarter, valued at $1 billion.
Construction of the tall tower offered a major challenge with differing cross-sectional dimensions such as the core wall, mega-columns and thin-blade columns in the 274-metre structure.
“Multiplex had to look at unconventional methods … it was not feasible to increase the stiffness of the columns conventionally as the increase in reinforcement and/or concrete strength that would be required was insurmountable,” explained Matt Irwin, design manager (engineering) at Multiplex.
“By adopting Boral’s high-stiffness Aspire mixes, [we were] able to substantially mitigate the risk to finishes from differential shortening as well as reduce the risk to program.”
Boral’s Aspire also provided a solution to improve stiffness, reduce drying shrinkage by 200 microstrain and lessen potential creep for thin elements. The concrete manufacturer went on to say that Multiplex estimates showed the Aspire mix helped save an additional 76 days during construction of The One at a cost of around $2.3 million.
The design and construct contract for The One (pictured mid-construction) was worth $291 million and built for the joint venture of Shayher Group and Bao Jia Group of Taiwan. The construction project took 1,359,642 people hours and used 30,000 cubic metres of concrete, according to Multiplex.
Boral said the concrete was specifically developed to maximise floorplans for commercial and high-rise buildings and increase productivity and led to the Urban Developer Industry Excellence Award for Best New Building Product in Australasia in 2019 which recognised an innovative building or construction product.