An innovative material, called cardboard-confined rammed earth, is composed entirely of cardboard, water and soil–making it reusable and recyclable. It eliminates the need for cement, boasting one quarter of the carbon footprint at under one third of the cost, compared to concrete. Walls can be made robust enough to support low-rise buildings.
https://www.rmit.edu.au/news/all-news/2025/sep/cardboard-construction