Plain old dirt could help build sustainable homes in poor areas.
Researchers in the University of Bath in the UK are experimenting with a technique called geopolymerization to transform subsoil into construction materials. Traditional building materials like brick and cement are made by firing a kiln at extremely high temperatures, which negatively impacts the environment.
“For a fired brick, that is typically fired at over a thousand degrees centigrade,” explained researcher Alastair Marsh. “And to make the ingredients you need for cement, you need to fire that at 1,450 degrees centigrade — very high temperatures, a very energy-intensive process and lots of carbon emissions associated with that.”
But geopolymerization of soil occurs at only 80 degrees Celsius and could become an environmentally-friendly alternative. The process requires the use of alkaline to transform the clay in soil into a glue that binds materials together.
Sustainable alternatives to cement and brick are needed to meet the needs of growing populations. The UN predicts that the global population will increase to 9.8 billion people by 2050, meaning that there will be an even greater strain on resources as well as the environment. But hopefully techniques like geopolymerization will make construction more sustainable by then.