An RMIT University engineering lecturer and his students have devised an innovative way to create more sustainable concrete – make it out of coffee.

The process uses the waste produced by the 1.3 million cups of coffee Australians make on a daily basis to create concrete to be used in the building of houses, office buildings and driveways.

Modern concrete mixes contain up to 80 percent sand, but while the resource is certainly plentiful, environmental concerns and a struggle to meet demand have highlighted the escalating need for an alternative ingredient.

The team, led by senior lecturer Dr Srikanth Venkatesan, has found that by replacing 10 percent of the sand with coffee grounds they can create a viable and sustainable mix while recycling a major source of food waste.

"The biggest challenge is ensuring the addition of spent coffee grinds does not lead to a reduction in strength of concrete, and this is the focus of further testing and development to make this product viable for use in real-world applications," says Venkatesan.

In Melbourne alone, an estimated 156,000 kilograms of coffee ground waste is produced a month.

"It seems fitting then that we’re working on this project in Melbourne, a city known for its great coffee culture," says Senura Kohombange, one of the engineering students involved in the project.

The team's 'coffee bricks' will be just one of many projects that will be on show at RMIT's EnGenius event on Wednesday, October 23.

"We are very excited to present the project, share the idea with others and showcase how some innovative thinking can turn a waste product into an everyday construction material," says Kohombange.

Image: 123RF's Norasit Kaewsai, © 123RF.com