Without water or traditional building materials, what will hypothetical Martian settlers use to build their future homes? Worry no more: materials scientists at Northwestern University have developed “Martian concrete” using sulphur, which is abundant on our neighboring planet.
The key material in a Martian construction boom will be sulphur, says the Northwestern team. The basic idea is to heat sulphur to about 240°C [464°F] so that it becomes liquid, mix it with Martian soil, which acts as an aggregate, and then let it cool. The sulphur solidifies, binding the aggregate and creating concrete. Voila—Martian concrete.
The resulting bricks are apparently quite strong and readily recyclable. As the MIT Technology Review points out, “Martian concrete can be recycled by heating it, so that the sulphur melts. So it can be re-used repeatedly. It is also fast-setting, relatively easy to handle and extremely cheap compared to materials brought from Earth.”
Briefly, it’s worth noting that sulphur-based brick mixes were previously explored at McGill University in Montréal by a team of environmentally minded designers, including architect Vikram Bhatt. As I got to learn from Bhatt himself during a summer at the Canadian Centre for Architecture back in 2010, that group sought to reuse waste sulfur as a building material.
One of the more interesting and, if I remember correctly, totally unexpected side-effects was the discovery that full-color images could be transferred to the bricks with a startling degree of verisimilitude, as the following two photos make clear.
[Images: Photos by Geoff Manaugh, originally published here].
Of course, this feature is presumably rather low on the list of details future astronaut-architects will be hoping for as they build their first encampments on Mars.
More practically, one thing I’d love to learn more about would be the possibility of novel architectural structures constructed using sulfurous concrete in the lower-gravity environment of Mars. Would the planet’s weaker gravity augment an architect’s ability to construct ambitious spans and arches, for example, because the materials themselves would be substantially lighter? Or, conversely, would the planet’s gravitational strength already be accounted for by a reduced density of the material, negating gravity’s diminished pull?
Put another way, the idea of ultra-light sulphur-concrete vaults and arches covering distances and spans that would be terrestrially impossible is quite a beautiful thing to imagine—and, coupled with those image-transfer techniques seen by Bhatt and his team at McGill, could result in vast new galleries and chapels illustrated with Martian frescoes, a high-tech return to older representational techniques from art history.