Using Spent Coffee Grounds for Making Concrete Can Greatly Boost Circularity

Engineers in Australia have developed a method to make concrete nearly 30% stronger by mixing it with waste coffee grounds turned into biochar through a low-energy process called pyrolysis. This process involves heating organic waste in the absence of oxygen, which can help increase the recycling rate of waste material. However, due to its high organic content, it is unsuitable for direct use in structural concrete. Pyrolysing spent coffee grounds at 350°C led to a 29.3% enhancement in the compressive strength of the composite concrete blended with coffee biochar.

The new method replaces a portion of the sand for making concrete, which currently stands at 50 billion tonnes globally every year. The ongoing extraction of natural sand from river beds and banks has a significant environmental impact, as it is finite and has long-lasting challenges in maintaining a sustainable supply of sand due to the finite nature of resources and the environmental impacts of sand mining.

Replacing sand with biochar from spent coffee grounds could not only strengthen concrete but also help the environment and reduce waste. Australia produces 75 million kilograms of coffee grounds annually, with most of this organic waste ending up in landfills. The research is still in its early stages, but the findings offer an innovative way to greatly reduce the amount of organic waste that goes to landfill.

Read More @ Sustainability Times

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