Martian soil could be pressed into making strong bricks

Washington, April 28 ( IANS) Experimenting with Mars-like soil, researchers have found that the Red Planet's soil could be turned into bricks just by applying pressure to compact the soil -- without needing to use an oven or additional ingredients.

The iron oxide, which gives Martian soil its signature reddish hue, acts as a binding agent, said the study published in the journal Scientific Reports.

This NASA-funded study assumes significance in view of the fact that US space agency plans to send a manned mission to Mars in the 2030s.

"The people who will go to Mars will be incredibly brave. They will be pioneers. And I would be honoured to be their brick maker," said the study's lead author Yu Qiao, Professor at University of California - San Diego.

Proposals to use Martian soil to build habitats for manned missions on the planet are not new.

But this study shows how astronauts would need minimal resources to do so. Previous plans included nuclear-powered brick kilns or using complex chemistry to turn organic compounds found on Mars into binding polymers.

To make bricks out of Mars soil simulant, without additives and without heating or baking the material, two steps were key.

One was to enclose the simulant in a flexible container, in this case a rubber tube. The other was to compact the simulant at a high enough pressure.

The amount of pressure needed for a small sample is roughly the equivalent of someone dropping 10-lb hammer from a height of one metre, Qiao said.

The process produces small round soil pallets that are about an inch tall and can then be cut into brick shapes.

The engineers believe that the iron oxide, which gives Martian soil its signature reddish hue, acts as a binding agent.

They investigated the simulant's structure with various scanning tools and found that the tiny iron particles coat the simulant's bigger rocky basalt particles.

The iron particles have clean, flat facets that easily bind to one another under pressure.

Researchers also investigated the bricks' strengths and found that they are stronger than steel-reinforced concrete.

--IANS

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