An ordinary construction brick, left, and an experimental brick made of a protein/lunar regolith mixture. | Photo by Mia Allende
By Edmund L. Andrews
Researchers find a way to build Mars and moon habitats using local materials that could also lead to more energy-efficient concrete right here at home. Together, the researchers have used animal protein to make a promising form of concrete that could solve problems on Mars as well as Earth.
“I never expected to be working with NASA,” Lepech recalls. “My research focuses on sustainable civil engineering and building systems – recycling heavy materials, minimizing waste. The folks at Ames came and said they had a big problem with materials management in space that might be super interesting to me. And they were right. What interests me the most is how we could use this to reduce waste on Earth.”
Indeed, the production of concrete accounts for 5% of all human-generated carbon emissions – a significant share. It’s the binding agent – the boiled limestone – that accounts for much of that.
In the search for a less energy-intensive alternative, Loftus and Lepech turned to biology. Living organisms use proteins to make things as tough as shells, bones, and teeth, so the researchers began working on a concrete bound together with a protein from bovine blood. The protein is a fairly cheap by-product of slaughterhouses, and it is known to become very gluey when mixed with soil.
To replicate the conditions on Mars and the moon, Lepech has combined the protein with simulated extraterrestrial soils that are similar to what’s on Mars and the moon. And because Mars has much lower gravity than Earth – bad for cement mixing – the researchers did their mixing with a vacuum technology that is used to make the composite materials in products such as boat hulls.