Australian engineers create reusable building material with quarter carbon footprint

Sydney: Engineers in Australia have developed a recyclable building material made from cardboard, soil and water that has just a quarter of the carbon footprint of conventional concrete, according to the Royal Melbourne Institute of Technology (RMIT).

The material, known as cardboard-confined rammed earth, eliminates the need for cement, reducing emissions and costing less than a third of concrete, RMIT said in a statement on Monday.

“By simply using cardboard, soil and water, we can make walls robust enough to support low-rise buildings,” said researcher Ma Jiaming, lead author of the study published in the journal Structures.

In another study, Ma found that combining carbon fiber with rammed earth delivered strength on par with high-performance concrete. He said the innovation could reshape building practices by using locally sourced, recyclable materials, aligning with global sustainability and net-zero goals.

Rammed earth structures are particularly suited to hot climates, as they naturally regulate indoor temperatures and humidity. The process involves compacting a soil-water mix inside cardboard formwork that can be made on-site, reducing reliance on heavy transported materials.

Australia sends more than 2.2 million tonnes of cardboard and paper to landfill annually, while cement and concrete production contributes about 8 per cent of global emissions.

The RMIT team said the technology could prove especially valuable in remote regions rich in red soil and is now looking for industry partners to scale up the innovation.