Aussie engineers turn cardboard waste into strong building material

Australian engineers at the Royal Melbourne Institute of Technology (RMIT) have developed a sustainable building material called cardboard-confined rammed earth, which combines cardboard, water, and soil to create strong walls suitable for low-rise buildings. This innovation addresses two major issues: reducing cardboard waste—over 2.2 million tons of which end up in Australian landfills annually—and cutting carbon emissions associated with cement and concrete production, which contribute about 8% of global emissions. The new material has roughly one-quarter of concrete’s carbon footprint and costs less than one-third as much, eliminating the need for cement by using compacted soil confined within cardboard tubes. Inspired by traditional rammed earth construction and designs like Shigeru Ban’s Cardboard Cathedral, the RMIT team has created a formula to determine the material’s strength based on cardboard tube thickness. The material can be produced on-site by compacting soil and water inside cardboard formwork, reducing transportation costs and logistical complexity by relying mostly on locally sourced materials.