Modern construction depends heavily on cement. It’s in our homes, roads, bridges, and nearly every structure around us. But there’s a hidden cost: producing cement generates around 8% of global CO₂ emissions every year, making it one of the most polluting industrial materials on the planet. Meanwhile, huge quantities of cardboard and paper end up in landfills instead of being reused.
Researchers have been asking an important question: Is there a cleaner, smarter way to build? And the answer might come from two simple materials—earth and recycled cardboard.
The Challenge: Reducing Cement’s Massive Footprint
A research team from RMIT University in Australia set out to explore alternatives to cement. Their idea was simple yet bold: create strong building materials using minimal processing and maximum recycling.
They focused on something humanity has used for thousands of years: rammed earth, a mixture of soil and a small amount of water compacted tightly together.
From this, they developed two innovative construction materials—both made without cement, more sustainable, stronger, and cheaper to produce.
Here’s what sets them apart:
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Rammed earth encased in recycled cardboard tubes
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Rammed earth enclosed in carbon-fiber tubes
In both cases, the tube acts as a structural shell, eliminating the need for cement altogether.
Returning to Earth-Based Construction
Building with earth is far from new. Ancient civilizations relied on rammed earth to form houses that naturally regulated temperature, staying cool during hot summers and warm in the winter—without electricity.
However, with industrialization, concrete became the dominant material, pushing earth-based techniques aside. Now, as climate change accelerates, interest in natural materials is returning.
Earth has several advantages:
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It’s available almost everywhere
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It requires little processing
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It produces minimal pollution
But it has one weakness: it can crack under heavy loads. The RMIT researchers solved this by placing the earth inside a strong, protective tube. This prevents the soil from expanding and cracking, making it far more stable—without a single drop of cement.
Option 1: Recycled Cardboard Tubes
The first material uses compacted soil wrapped inside recycled cardboard tubes. These tubes act as both the mold and the reinforcement. Surprisingly, the result is stronger than traditional rammed earth, and in some cases comparable to cement-stabilized soil.
Best of all, this eco-friendly material produces up to 80% fewer emissions than standard concrete.
It’s ideal for low-rise buildings, garden structures, and sustainable housing projects.
Option 2: Carbon-Fiber Tubes
The second technique replaces cardboard with carbon-fiber tubes. Carbon fiber is lightweight yet extremely strong—often used in aircrafts, racing cars, and advanced engineering.
When combined with rammed earth, the result is a column that:
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rivals high-strength concrete
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weighs significantly less
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has a reduced environmental impact
This makes it suitable for regions with earthquakes or where lightweight structures are required. Although more expensive than cardboard, its performance is impressive.
These early experiments show tremendous potential. While long-term studies are still needed, the results point toward a future where sustainable, low-carbon construction becomes the norm.
By rethinking age-old materials like earth and giving waste products like cardboard a second life, researchers are showing that strong, durable, and eco-friendly buildings are not just possible—they’re within reach.
