Planetary securityUsing concrete for space colonies

“Be prepared.” This famous mantra isn’t just for the Boy Scouts of America. The need to build durable infrastructure on other planets is coming, and we must be ready. To prepare, Penn State researchers have teamed up with NASA to explore how cement solidifies in microgravity environments.

“It is no longer a question of if we will need to colonize other planets, but a question of when,” said Aleksandra Radlińska, assistant professor of civil engineering at Penn State and principal investigator on the project. “Once we begin sending humans on missions to the Moon and Mars, we will have to provide them with safe environments to stay in for the duration of their mission.”

Penn State notes that researchers have long been studying the reaction of cement when it mixes with water here on Earth; however, there are still questions remaining and little is known about how this process plays out in space, where there is little to no gravity. The goal of this research is to better understand the complex process of cement solidification when gravity is taken out of the equation.

“We’re looking at how cement hydrates and how its microstructure develops over time,” said Radlińska. “We want to know what grows inside cement-based concrete when there is no gravity driven phenomenon.”

Microstructural development of concrete occurs in stages — when the cement is exposed to water and when the mixture undergoes the complex process of solidification. What happens during these stages leads to the development of elaborate combinations of amorphous and crystal phases. The shape, volume, and distribution of these determines the properties of the hardened material. This process is altered when gravity is minimized considerably, which changes the crystalline structure, and ultimately the material itself.

To learn more about how cement reacts in these environments, the researchers embarked on a two-phase study.