Adding a perk to concrete with coffee grounds

According to Close the Loop, the average cafe creates 60 kg of spent coffee grounds a week, more than 90% of which ends up in landfill. Looking to divert used coffee grounds from landfill, a coffee-loving engineering lecturer and his students from RMIT University turned to the construction industry. Perhaps spent coffee grounds could be used in concrete?

Most concrete mixes contain up to 80% sand, a resource that is under threat globally and cannot sustainably match current demand.

The research team found they could replace up to 10% of sand in a concrete mix with coffee grounds, producing ‘coffee bricks’ that will be on display at RMIT’s EnGenius event on Wednesday, 23 October.

Engineering students Senura Kohombange and Anthony Abiad worked with Senior Lecturer Dr Srikanth Venkatesan to test and develop the coffee bricks.

“It seems fitting than we’re working on this project in Melbourne, a city known for its great coffee culture,” Kohombange said.

“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.

“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,” he said.

Distinguished Professor Adrian Mouritz, Executive Dean School of Engineering, said RMIT was proud to produce the next generation of engineers who were designing solutions to real-world problems.

“EnGenius takes engineering out of the classroom and brings it to life. Many of these projects focus on making our world a better place, be it more inclusive or more sustainable,” he said.

Image caption: Students Anthony Abiad and Senura Kohombange.