When humans go to the moon or Mars to live, they must create safe places to live and work.
The answer may be the most widely used building materials on the ground, concrete. They are strong and durable enough to provide protection from cosmic radiation and meteorites, and may be manufactured using materials available on these celestial bodies.
Concrete is a mixture of sand, gravel and rock mixed with a paste made of water and cement powder.
Although it sounds simple, the process is very complex, and scientists still have questions about chemistry and microstructures and how changes in gravity can affect this process.
A recent examination at the International Space Station examined the cement freeze in microgravity to help answer these questions.
In order to exploit the microgravity of the cement freezing project (MICS), the researchers first mixed trilium silicate (Ca3SiO5 or C3S) and extraterrestrial water.
The main mineral component of most commercially available cement, C3S regulates many chemical reactions and properties.
MICS explored whether freezing cement in microgravity would lead to unique microscopic structures and provide the first comparison of cement samples processed on the ground and in microgravity.
The researchers reported their findings in a paper published in Frontiers in Materials, “The effect of microgravity on the microscopic development of tricalcium silicate paste (C3S).”
“On missions to the Moon and Mars, humans and equipment will have to be protected from extreme temperatures and radiation,” said Alexandra Radlinska, senior researcher at the University of Pennsylvania.
Materials like concrete. Concrete is much stronger and offers better protection than many materials. ”
Another important feature of concrete is that explorers can theoretically build on those extraterrestrial objects with available resources, such as dust on the moon, also known as the lunar system.
This eliminates the need to transport building materials to the moon or Mars, which significantly reduces costs.
Scientists know how a solid behaves and hardens it on Earth, but it is not yet known whether the process is the same in space.
“How hard? What will be microscopic?” Radlinska said. “These are the questions we’re trying to answer.”
The researchers devised a series of mixtures that varied different types of cement powder, the number and types of additives, the amount of water, and the time allowed to moisten.
When granules of cement powder dissolve in water, their molecular structure changes. The crystals are formed throughout the mixture and intertwine with each other.
In the first assessment, samples processed at the space station showed significantly greater changes in the exact structure of cement than those processed on Earth.
The main difference was increased porosity, or the presence of more open spaces.
“Increased porosity has a direct impact on the strength of matter, but we do not yet have space-based materials to measure its strength,” Radlinska said.
“Although concrete has been used on Earth for a long time, we don’t necessarily understand all aspects of the humidification process.
We now know that there are some differences between Earth and space systems and that one can examine the differences. “.
“Also, the samples were in sealed bags, so another question is whether they will have additional complications in open space environments.”
The microgravity environment of the plant primarily examines how cement moves to the Moon and Mars. Centrifuges on board can simulate gravity levels for those supernatural objects, which is not possible on Earth.
Cement samples containing simulated lunar particles processed in an orbital laboratory at different levels of gravity are being evaluated.
This shows that concrete can harden and develop into space, an important step towards the first structure built on the moon using materials from the moon.
“We have confirmed the hypothesis that this can be done,” Radlinska said.
“Now we can take the next step to find the folders of space and zero on Mars and between them, for changing gravity levels.”