Scientists Develop Strong, Sustainable Building Material From Soil And Cardboard

Engineers in Australia have developed an innovative building material that is strong, cost-effective, and more environmentally friendly than standard concrete. This new material has a much smaller carbon footprint and helps reduce the amount of waste sent to landfills. The material is known as cardboard-confined rammed earth. It is created using three basic ingredients: cardboard, water, and soil. This makes it easy to reuse and recycle, making it a more sustainable choice.

Why Is It Important

In Australia, millions of tonnes of cardboard and paper end up in landfills each year. At the same time, the production of cement and concrete is a major source of global carbon emissions, responsible for about 8% of all greenhouse gases worldwide.

The team at RMIT University in Melbourne have combined the strength of rammed earth, a traditional method that uses compacted soil, with cardboard to create a versatile and durable material suitable for real, long-lasting buildings.

What Is Rammed Earth?

Rammed earth is a building technique that involves compacting soil, often mixed with a small amount of cement, into forms to create strong walls. This traditional method requires a significant amount of cement, which is energy-intensive to produce and contributes to high levels of carbon dioxide emissions. The new material developed by RMIT researchers, cardboard-confined rammed earth, eliminates the need for cement altogether.

Big Benefits for the Environment and Costs

Dr Jiaming Ma, the lead researcher on the project, explains that this material has only a quarter of the carbon footprint of concrete and costs less than a third as much. This innovation could change the way buildings are constructed. Instead of relying on costly and polluting materials, builders can use materials available right on-site, soil and cardboard. Since the cardboard is recyclable and the soil is natural, the entire building process becomes much more sustainable.

How It Works in Practice

For making the cardboard-confined rammed earth, soil and water are mixed and then compacted inside cardboard tubes or boxes, which hold everything in place. This compaction can be done manually or with machinery. Emeritus Professor Yi Min 'Mike' Xie, an expert in structural engineering, says this new method could lead to a more efficient and environmentally friendly way of building.

This material is especially useful in remote parts of Australia, where it can be difficult and expensive to bring in traditional building supplies.

Using local soil along with cardboard means that buildings can be constructed cheaply and sustainably without the need to transport materials from far away. Rammed earth buildings also help regulate indoor temperatures. The thick, dense walls store heat and release it slowly, keeping buildings cool in hot weather and warm in cooler weather.

What's Next?

The team at RMIT is looking to work with industry partners to further develop this material and bring it into more widespread use. This innovation shows simple, natural materials can be creatively used to make sustainable, affordable, and strong buildings. It is a promising step towards a construction industry that is better for the planet and more cost-effective for people.

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