Explorers plotting to settle on Mars may be able to turn the planet’s red soil into bricks with no need of using an oven or extra materials. Instead, they would just require putting the pressure to solidify the soil. These are according to study findings published in Scientific Reports on 27th April 2017. The study was written by a team of engineers at the University of California San Diego and funded by NASA. The research is even more important because Congress passed a bill, signed by President Donald Trump in March 2017, instructing NASA to send an operated mission to Mars in 2033.
The UC San Diego engineers were originally trying to reduce the number of polymers needed to shape Martian soil into bricks and accidentally realized that they needed none. To make bricks out of Mars soil simulant, without additives and without heating or baking the material, two steps were very important. The first step was to enclose the simulant in a flexible container, like a rubber tube. The second step was to compress the stimulant at a high enough pressure. The pressure amount required for a small sample is approximately the equivalent of someone dropping 10-lb hammer from a height of one meter.
The process produces small round soil pallets which are almost 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, serves as a binding agent. They investigated the simulant’s structure with several scanning tools and discovered that the small iron particles coat the simulant’s bigger rocky basalt particles. The iron particles have clean, flat facets which simply join under pressure.
Researchers also studied the bricks’ strengths and discovered that even without rebar, they are stronger than steel-reinforced concrete. They said their technique may be compatible with additive manufacturing.