Coffee offers performance boost for concrete

Coffee offers performance boost for concrete

Engineers in Australia have found a way of making stronger concrete with roasted used-coffee grounds, to give the drink-additive a “double shot” at life and reduce waste going to landfills.

Lead author Dr Rajeev Roychand from RMIT University said the team developed a technique to make concrete 30% stronger by turning waste coffee grounds into biochar, using a low-energy process without oxygen at 350 degrees Celsius.

“The disposal of organic waste poses an environmental challenge as it emits large amounts of greenhouse gases including methane and carbon dioxide, which contribute to climate change,” said Roychand, from the School of Engineering.

Australia generates 75 million kilograms of ground coffee waste every year – most of it goes to landfills. Globally, 10 billion kilograms of spent coffee is generated annually.

Published in the Journal of Cleaner Production, the study by RMIT engineers is the first to prove that waste coffee grounds can be used to improve concrete.

“The inspiration for our work was to find an innovative way of using the large amounts of coffee waste in construction projects rather than going to landfills – to give coffee a ‘double shot’ at life,” said Roychand, a Postdoctoral Research Fellow at RMIT.

“Several councils that are battling with the disposal of organic waste have shown interest in our work.

“They have already engaged us for their upcoming infrastructure projects incorporating pyrolysed forms of different organic wastes.”

Pyrolysis involves heating organic waste in the absence of oxygen.