Sustainable buildings don’t need full glass – you only need 40 per cent of walls to be glassed to gain the full benefits of light,” Mr O’Dwyer said. The project won H2O an Australian Institute of Architects award last year.
CONCRETE’S great advantages as a building material are its strength and long service life, but it’s not usually extolled for its beauty – until now.
Melbourne architects H2O have been pioneers in a new product, ”gleaming white” precast concrete, that is dramatically expanding the role of concrete and helping the firm to win awards on the way.
The consistent super white panel allows the cost advantages of standard grey precast concrete at a minimum premium. ”The benefits are a handsome, elegant and self-finished panel,” said H2O director Tim Hurburgh, a former chairman and director of Bates Smart.
And as fellow director Mark O’Dwyer put it: ”White has always worked well as a colour – look at the Parthenon,” he said.
H2O’s innovative precast concrete has been used in Deakin University’s international centre and business building, Swinburne University’s advanced technologies centre in Hawthorn, the Lakeside Stadium in Albert Park and a performing arts centre at Genazzano College in Kew.
Concrete technology was known and used in ancient Rome, but after the empire collapsed, use of concrete became scarce until the technology was re-pioneered in the mid-18th century. Precast concrete – the casting of concrete in a recyclable mould that is factory-cured before being moved on site – was first used in Britain 100 years ago. According to Mr Hurburgh, its advantages are quality control, speed of erection and design flexibility. Precast concrete products were first used in Australia in the 1920s before we followed the Europeans’ use of the product in high-rise residential estates, building the familiar housing commission blocks.
Mr O’Dwyer began working on coloured precast concrete five years ago with trade suppliers such as Vic Mix and manufacturers, including Advanced Precast. ”The early results were shocking – the concrete was not curing properly, you could see lots of marks,” he told BusinessDay. Specialist training evolved for workers on site, but the white concrete was eventually developed. Other colours such as black were tested, but Mr O’Dwyer said these were difficult. ”Like clothes, colours are intense and don’t age as well, it’s hard to get consistency. White is also not easy. The more intense the colour – UV kills it, but white is OK,” he said.
One big danger for white, precast concrete is that it will show water. ”On the buildings, the parapet must be shaped backwards so that rain water and dirt do not flow down the surface and mark it,” he said.
The Swinburne project was the first in Australia to be entirely clad in load-bearing white panel with a universal dot matrix – like the pores of the skin – providing windows, ventilation and engineering vents.
”It creates an eye-pleasing pattern. I don’t like full glass buildings. Sustainable buildings don’t need full glass – you only need 40 per cent of walls to be glassed to gain the full benefits of light,” Mr O’Dwyer said. The project won H2O an Australian Institute of Architects award last year.
At the Lakeside Stadium in Albert Park, the white precast concrete was used as a V column supporting the cantilevered steel roof structure of the new North Stand.
Mr O’Dwyer tipped greater use of coloured precast concrete in construction given its speed, ease of construction, quality control and design flexibility. ”There will be greater experimentation with panel shapes, profiles and factory finishes,” he said.