Say Goodbye To Cement With This New Eco Friendly Alternative – BGR

Concrete is the backbone for modern construction, serving as the foundation for any major build. It’s known for its cost-effective properties, unmatched strength, longevity, and versatility, being used for houses, buildings, roads, bridges, and more. It’s been a standard in builds for decades, especially in residential homes, but it’s also a major contributor to global carbon dioxide emissions. Around 8% of global CO₂ emissions come from cement production, the bonding agent used in concrete. For years, researchers and scientists have been proposing eco-friendly and more sustainable alternatives. But concrete is the second most widely used material after water, it makes sense why finding an alternative is a challenge. There may be an answer for residential and low-rise builds, or two, really, when the materials are used together. The solution includes rammed earth, also called compacted soil, and cardboard reinforcement. Yes, that cardboard.

Researchers found that cardboard-confined rammed earth (CCRE) which basically shoves earth into low-cost cardboard tubes, significantly enhances the strength of cardboard alone by more than tenfold. That’s actually stronger than using concrete to stabilize the compacted earth. But CCRE also offers “substantial reductions” in carbon emissions and a lifespan of about 25 years for CCRE alone. The lifespan is up to 75 years for both cement-stabilized rammed earth and concrete. Yes, for that last bit, there is a difference between concrete and cement, related to the composition, development process, and environmental impact. But mixing the materials can vastly improve lifecycles thereby extending the lifetimes of the structures or buildings they’re used in, another reason why concrete stands as a top choice, currently.

This isn’t the first time scientists discovered concrete substitutes. Montana State University researchers invented an ultra-hard alternative that employs fungus and bacteria. Another revolutionary option, from a company called C-Crete Technologies, doesn’t have any cement in it, but it’s ideal for commercial projects. Northwestern University researchers also developed a unique paste for concrete that can soak up carbon dioxide. But the CCRE or cardboard rammed earth offers a suitable, residential application that’s extremely cost-effective, is available in vast quantities, and includes all the properties of traditional cement.

Rammed earth has been used in construction for centuries, but compacted earth can shift and break apart, which is where the cardboard reinforcement matters. Recycled cardboard tubes are used as a sort of jacket, keeping the compact soil in place, and that serves as a core to support the surrounding material. The rammed earth is first mechanically compacted into five layers within the tube, improving density, with a thin polyethylene film placed between the soil and tube wall to prevent water erosion and surface damage. This is repeated, layer after layer, until the hollow tube is full. Wet sand poured around the tubes are held in place by the cardboard, acting as a bonding agent.

For the earth, teams can use soil at the jobsite, meaning fewer materials have to be shipped in. Moreover, rammed-earth structures provide unique benefits like natural temperature regulation, reduced heating and cooling costs, and reduced carbon emissions. There’s no plan to use the material as of yet. But the researchers note future studies should “focus on enhancing the durability and weather resistance of CCRE and exploring their applicability in a broader range of structural contexts.”