Goodbye Cement: This Eco-Friendly Alternative Could Revolutionize Construction

If you're climate-conscious, you might be interested to know that conventional cement production accounts for a massive chunk of annual global carbon dioxide emissions. Concrete and cement have been the standard for building houses and skyscrapers for decades, but the energy required to produce cement, especially for firing limestone in kilns, results in a massive environmental impact. There's an alternative right under our noses, though. Researchers in Australia have introduced a new building option called cardboard-confined rammed earth, a material made from just soil, water, and recycled cardboard. This innovation offers an interesting solution to the pollution that's generated by conventional building materials. 

In addition to pollution from manufacturing, construction sites generate millions of tons of physical waste each year, including discarded cardboard and paper. Finding a way to reduce both the carbon output of construction and the paper waste addresses two important issues at once. By looking back at ancient building practices and combining them with modern recycling technology, a team from the Royal Melbourne Institute of Technology (RMIT), a well-known public research university in Australia, developed a method that not only eliminates the need for cement but also reduces costs and streamlines material transportation. This material proves that going green doesn't mean sacrificing structural stability. It can also be used as a nice-looking drywall alternative for your home. If you're looking for a solution to cover your basement's dirt floor, rammed-earth is a good choice, as well.

Using earth as a construction material is a practice that's been done for thousands of years. This technique is often referred to as rammed earth, a process of pressing soil together with water. Historically, the challenge has been the material's tendency to shift or break apart when subjected to significant weight, leading modern builders to mix in cement to make it more stable. The RMIT researchers solved this by using recycled cardboard tubes to act as a structural jacket, which keeps the compacted soil mixture in place. This method doesn't require cement, yet it still produces a durable, solid material.

This cardboard tubing is unique because it holds the wet soil during construction and stays in place to provide continuous support afterward. The durability of the finished column depends on the thickness of the cardboard tube, and the engineering team has developed a mathematical formula that allows designers to calculate the material's strength based on that thickness. 

This material is also affordable. Researchers found that cardboard-confined rammed earth costs less than one-third as much as conventional concrete construction. The fact that local soil can be used also reduces the amount of materials and equipment that need to be hauled to the construction site, making transportation and planning easier and lowering the overall cost of the project. By avoiding the use of cement altogether, this technology removes concerns about finding the right way to dispose of cement waste, as well. This means it offers a cleaner building process from start to finish.

One of the biggest benefits of this material is its environmental performance compared to traditional concrete. The process has a carbon footprint that is only about one-quarter of that produced by conventional concrete construction that relies on cement. This is an 80% reduction in carbon output by just substituting a repurposed waste product for a manufactured one. 

The material also continues to provide environmental savings long after the structure is built. Rammed-earth structures have a natural ability to store heat, which means the walls can absorb thermal energy and gradually release it. This helps regulate the building's temperature, keeping it cool during the hottest parts of the summer and warmer during the colder months. This has the potential to reduce utility-related carbon emissions and lower energy bills. While the use of rammed earth for this is promising, research teams are still working to determine how the material will hold up over many years of weather exposure and use.