No bake Mars bricks

louis · 2017-04-27 14:04:20

https://www.sciencedaily.com/releases/2 … 091723.htm

I think someone mentioned this no bake technique before for making (very strong) Mars bricks.

But it does seem rather important in terms of the ability of an early Mars colony to get involved in construction so I thought I would post a link to this article that has just appeared.

SpaceNut · 2017-04-27 18:36:32

Yes I remember some other brick conversation which talked about sulfur as a binding agent.

article:

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 meter, 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.

mixed units... 10 lbs = 4.55 kg for the 1 meter compression does not sound like after stacking the bricks upward that they would hold together... I would think that we would want more force and need to know the time duration of the force to be able to test for the stacking of them.

The compression is also compaction when its soils and I think that the mineral sampling for the simulant while it seems promissing may not yeild to the reality of mars.

Some links for the topic as seen here on earth.

https://en.wikipedia.org/wiki/Soil_compaction

http://www.multiquip.com/multiquip/pdfs … sion_1.pdf

http://www.fdot.gov/research/completed_ … _2_rpt.pdf

SpaceNut · 2017-06-23 16:48:45

Antius wrote:

This may be a key enabling technology:
https://www.theverge.com/2017/4/27/1543 … n-missions
If Mars soil behaves in the same way as the simulant, we wont need steel frames to manufacture these habitats. Just hydraulic rams and steel moulds, forming components from rammed regolith. These components can be manufactured to slide together or be bolted together.
This might provide a use for Louis's solar power, as regolith will be too cold to collect at night and the steel within the moulds too brittle at low temperatures.

Mars-like soil can be pressed into strong bricks — which could make building easier on the Red Planet And you don’t need to add any extra ingredients

Before
mars_brick_1.0.jpg

After

louis · 2017-06-24 05:05:11

If we had a Mars Analogue Facility we could begin testing how to use these bricks in practice. Presumably we would need a sealant of some kind for pressurised environments. So that leads to the question of what is the most appropriate sealant. Perhaps a carbon-based plastic rather than something based on calcium (which appears to be in short supply on Mars)?

Oldfart1939 · 2017-06-24 08:11:02

Louis-

Based on chemical availability, I'd suggest we use a mixture of styrene and divinylbenzene as a binder-sealant. When AIBN (azo-bis-isobutyronitrile) is added to the total mixture, these "bricks" could be polymerized at 65 degrees C for several hours. This combination of monomers when added to regolith, would make a decent structural material. It would be easy to do these tests here on Earth at the desert research station, just to find out how much monomer mixture would be needed to make structurally sound products. We could possibly add some butadiene and acrylonitrile to the mix, making an ABS reinforced with regolith. Neither of the basic monomers is terribly volatile so the mixing could be done in something resembling a cement mixer with the regolith added. Ram the moist slurry into molds , cure them, and then use. This isn't really a "no-bake" process, but the temperatures involved are relatively modest.

SpaceNut · 2017-06-24 10:10:43

Sounds like the bricks will be air tight but then what do we do to layer them in stacks if we need a some what controlled environment to make them. Would the slurry act like a cement between the bricks if we can control temp while it sets.

Oldfart1939 · 2017-06-24 15:53:08

I would suggest a "caulk-like" bonding cement, but with a fairly hi boiling point volatile solvent. It could both be absorbed by the bricks and some evaporation would occur at Mar's atmospheric pressure. Possible an epoxy cement with a slow hardening polymerization rate?

louis · 2017-06-25 08:34:05

I'm not really up on the chemistry of this - are such resins basically polymers formed from carbon, hydrogen and oxygen? - in other words material easily accessed on Mars?

Oldfart1939 wrote:

I would suggest a "caulk-like" bonding cement, but with a fairly hi boiling point volatile solvent. It could both be absorbed by the bricks and some evaporation would occur at Mar's atmospheric pressure. Possible an epoxy cement with a slow hardening polymerization rate?

Oldfart1939 · 2017-06-25 09:46:53

Both styrene and divinylbenzene are entirely hydrocarbons; styrene is C8H8, and divinylbenzene (DVB) is C10H10. Here on Earth, styrene is produced on a massive scale and is very inexpensive. DVB is a bit more expensive and slightly trickier to manufacture w/o spontaneous polymerization. The amount of DVB required is generally around 5% of the polymer mix in order to produce a strong, rigid structure. The warming is needed to initiate the polymerization process through decomposition of the AIBN free radical source.

Butadiene for making an ABS polymer mixture is also a pure hydrocarbon: C4H6. If we need any nitriles, these require an additional element found in the Mars atmosphere: Nitrogen.

Oldfart1939 · 2017-06-25 09:55:21

There are a whole family of these initiators called VAZO-xx, where the xx = a temperature in degrees Celsius, and identifies the temperature required for initiation of the decomposition. They are manufactured by DuPont. We could probably find an initiator for a lower temperature polymerization, which would thereby be a less energy intensive process.

Antius · 2017-06-25 14:08:17

Oldfart1939 wrote:

There are a whole family of these initiators called VAZO-xx, where the xx = a temperature in degrees Celsius, and identifies the temperature required for initiation of the decomposition. They are manufactured by DuPont. We could probably find an initiator for a lower temperature polymerization, which would thereby be a less energy intensive process.

The bricks made with regolith simulant were apparently as strong as fired clay bricks, without any binder. Why would we use one if we didn't have to? The great thing about compressed soil components is that the materials are free.

SpaceNut · 2017-06-25 15:07:41

To create an air seal between layers of stacked mars brick and to keep them from direct weathering from dust storms.....

louis · 2017-06-25 18:42:15

I would think we would have heaped regolith on the exterior so a sealant on the exterior of the bricks is probably not an issue, as long as you have a good interior sealant.

SpaceNut wrote:

To create an air seal between layers of stacked mars brick and to keep them from direct weathering from dust storms.....

Oldfart1939 · 2017-06-25 19:07:52

If we are indeed attempting to eliminate atmosphere loss through slow seepage to the surrounding environment, a polymer coating BOTH inside and out would seem prudent.

SpaceNut · 2017-06-25 19:13:16

Then as Louis suggested the complete sealing of the outside would be covered with a layer of mars regolith but it does not need to be all that much but we will need a method to be able to tell when its been blown away so that it can be replaced as needed.

Oldfart1939 · 2017-06-25 20:02:56

What I would suggest is a thin solution of the monomer mixture which bonds the regolith together. This type of polymer is commonly called a "living polymer," and once more virgin substrate becomes available--polymerization continues. "Termination" occurs due to exhaustion of polymerizable monomer.

Antius · 2017-06-26 03:14:56

Oldfart1939 wrote:

If we are indeed attempting to eliminate atmosphere loss through slow seepage to the surrounding environment, a polymer coating BOTH inside and out would seem prudent.

Understood. So we are talking about a polymer paint rather than a binder. This would appear to be prudent to prevent slow air loss and to minimise abrasion.

There is also the issue of water migration into the material and subsequent damage due to freezing cycles. Zubrin initially pointed out in 'Case for Mars' that this would tend to seal slow leaks. But it could also lead to frost shattering of the brickwork.

There has been speculation of the Martian surface being wet with saturated brines in some places. If so, it is possible that damp proof liners may be needed as well. Soil building techniques have been used successfully even in wet climates here on Earth. There are earth buildings in England and Wales that are centuries old. But the key to making them work is to keep them dry. The place that damp tends to enter is through the ground. When adobe is wetted, it loses half its strength and become vulnerable to abrasion.

Oldfart1939 · 2017-06-26 08:07:28

Antius wrote:

Understood. So we are talking about a polymer paint rather than a binder. This would appear to be prudent to prevent slow air loss and to minimise abrasion.

Correct. A "paint" chemically identical to the binder in the "bricks' will react and make a uniform portion of the structure rather than a mere "coating."

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#1 2017-04-27 14:04:20

No bake Mars bricks

#2 2017-04-27 18:36:32

Re: No bake Mars bricks

#3 2017-06-23 16:48:45

Re: No bake Mars bricks

#4 2017-06-24 05:05:11

Re: No bake Mars bricks

#5 2017-06-24 08:11:02

Re: No bake Mars bricks

#6 2017-06-24 10:10:43

Re: No bake Mars bricks

#7 2017-06-24 15:53:08

Re: No bake Mars bricks

#8 2017-06-25 08:34:05

Re: No bake Mars bricks

#9 2017-06-25 09:46:53

Re: No bake Mars bricks

#10 2017-06-25 09:55:21

Re: No bake Mars bricks

#11 2017-06-25 14:08:17

Re: No bake Mars bricks

#12 2017-06-25 15:07:41

Re: No bake Mars bricks

#13 2017-06-25 18:42:15

Re: No bake Mars bricks

#14 2017-06-25 19:07:52

Re: No bake Mars bricks

#15 2017-06-25 19:13:16

Re: No bake Mars bricks

#16 2017-06-25 20:02:56

Re: No bake Mars bricks

#17 2017-06-26 03:14:56

Re: No bake Mars bricks

#18 2017-06-26 08:07:28

Re: No bake Mars bricks

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