Good old mud can lower building costs

Summary

Buildings are expensive, but using mud can make concrete buildings cheaper. MIT researchers developed a method to use treated mud from building sites as molds for concrete using 3D printing. This replaces the costly wood molds usually used.

Buildings are expensive, but using mud can make concrete buildings cheaper. MIT researchers have developed a method called EarthWorks to use treated mud from building sites as molds for concrete using 3D printing, replacing costly wood molds.

Sandy Curth, an MIT PhD candidate, explains that soil from the ground or construction sites can create accurate and complex molds for custom concrete structures. This approach speeds up construction, reduces costs, and lowers carbon emissions.

Constructing wooden formwork is expensive and time-consuming because it requires building twice: once with wood and then with concrete.

Using soil for formwork simplifies this process. The EarthWorks method involves adding materials like straw and a wax-like coating to the soil to prevent water from draining out of the concrete. Researchers use large-scale 3D printing to create custom-designed formwork shapes from soil.

The EarthWorks method offers several advantages: it is cost-effective, easy to acquire, environmentally friendly, and can reduce carbon emissions from concrete construction by more than 50%. Soil molds are more flexible than wood, allowing architects and engineers to create custom concrete shapes more easily.

Curth highlights that this technique simultaneously creates shape-optimized building elements with the same energy as traditional building elements. He has founded a company called FORMA Systems to bring this method to the construction industry. Builders would need large 3D printers on-site but would save significantly on materials costs.

Curth envisions using this method for formwork and constructing entire buildings out of earth, making them inexpensive. This approach could systematize the production of adobe-like homes.

Journal Reference:

1. Alexander Curth, Natalie Pearl, Emily Wissemann et al. EarthWorks: Zero waste 3D printed earthen formwork for shape-optimized, reinforced concrete construction. Construction and Building Materials. DOI: 10.1016/j.conbuildmat.2024.138387