If we wish to inhabit a different planet, we need plans to make safe habitable structures. The difference in planetary conditions calls for research in material technology and NASA astronauts just took a ‘concrete’ step towards that.
Concrete is the most common material used to build structures on Earth because of its properties and its simplistic composition of sand, gravel and rocks. But, if it is to be used on another planet, it is important that those properties are still viable. To test this, astronauts aboard the International Space Station(ISS) made cement in microgravity under controlled conditions. The experiment is known as Microgravity Investigation of Cement Solidification(MICS) with the goal of understanding the complex process of cement solidification in space.
Last week on @Space_Station, astronauts including @NASA‘s @AstroSerena, @Astro_Feustel and @astro_ricky conducted @ISS_Research studying water jets, cement and much more! >> https://t.co/XPYOKcCNX6 pic.twitter.com/iODHaWvpPm
— NASA Marshall (@NASA_Marshall) July 3, 2018
Tricalcium Silicate is the main component of concrete that is responsible for the chemical properties of the material. Scientists mixed tricalcium silicate with water in various controlled conditions to understand the effects of microgravity on the microstructures that give the material its physical properties.
According to the research paper published in Frontiers in Materials, the researchers made multiple mixtures each with either different types of cement powder containing a number of additives of various types. They also used varying amounts of water for hydration over different periods of time. The cement was made in centrifuge that emulated gravity conditions, as experienced on Moon and Mars. The samples were sent back to Earth and compared with concrete that was made on Earth. The primary difference observed was that the concrete from space had more open spaces in its crystalline microstructure. This of course, would mean that the space concrete has lower strength but the reduction in strength is not yet measured.
Aleksandra Radlinska from Pennsylvania State University and co-author of the research explained, “Even though concrete has been used for so long on Earth, we still don’t necessarily understand all the aspects of the hydration process.” The research might shed light on concrete made on Earth that might lead to development of better techniques to make stronger concrete.