Construction is one of the largest industries in the world economy – worth $10 trillion globally – equivalent to 13 per cent of GDP.
But, Professor Jay Sanjayan, from Swinburne University of Technology, explains that construction has suffered for decades from remarkably poor productivity compared to other sectors.
While agriculture and manufacturing have increased productivity 10-15 times since the 1950s, construction remains stuck at the same level as 80 years ago, he said.
“That’s because construction remains largely manual, while manufacturing and other industries have made significant progress in the use of digital, sensing and automation technologies.
“We and other research groups see 3D-printed concrete as a possible solution to these problems. The technique will likely also give architects the freedom to inject more creativity into their designs for new structures,” said Sanjayan.
Modern civil infrastructure is almost entirely built with concrete. More than 20 billion tons of concrete is used per year, Sanjayan explains.
“The only material we use more than that is water.
“The construction industry is facing a number of serious problems, including low labour efficiency and high accident rates at construction sites.”
According to the Australian Bureau of Statistics, the construction industry has the highest rate of work-related injuries at 59 per 1000 workers.
There are also difficulties in quality control at construction sites, high levels of waste and carbon emissions, cost blow-outs, and challenges in managing large worksites with a vanishing skilled workforce.
Disruptive technologies such as 3D concrete printing can offer solutions.
3D construction uses additive manufacturing techniques, which means objects are constructed by adding layers of material.
Conventional approaches to construction involve casting concrete into a mould.
But additive construction combines digital technology and new insights from materials technology to allow free-form construction without the use of formwork.
Eliminating the cost of formwork is the major economic driver of 3D concrete printing. Built using materials such as timber, formwork accounts for about 60 per cent of the total cost of concrete construction.
It’s also a significant source of waste, given that it is discarded sooner or later.