Cast Basalt

Calliban · 2024-01-10 08:29:32

There is an old topic on basalt fibres, but we don't appear to have one on cast basalt. This material is finding increasing uses as corrosion resistant rebar in concrete, wear resistant tiles and pipe linings. The more I read about it, the more impressed I am with its capabilities. It has an obvious advantage over other materials on Mars in that its feedstock is available almost everywhere.

The moon society produced the following document proposing this material as ideal for lunar use due to its abundance.
https://www.moonsociety.org/wp-content/ … bound4.pdf

Basalt melts at temperatures of 1175 - 1350°C, depending on composition. For fibre production, the melt is typically heated to 1500°C to reduce viscosity. However, for large components like slabs, blocks and tiles, lower temperatures could be used. This would allow basalt to be cast in steel cased sand molds. On Mars, we could produce compressive structural members from cast basalt. Ideally, we would want to be able to mass produce a single, repeatable structural unit. Multiples of these would then be slotted together using dowel pins to form geodesic domes. These domes can then be covered in a thin layer of polyethylene sheeting and then covered with several metres of overburden before being pressurised.

If we could design a machine that could melt and injection mold these standardised repeatable units at a rate of thousands per hour, that would be a key step to making cheap habitable volume on Mars. We could build 50m diameter habitation domes in just a few days.

Last edited by Calliban (2024-01-10 09:03:15)

Void · 2024-01-10 09:03:51

I don't want to mess up yet another of your topics, but your building plans look rather good to me. It seems to me that also within tubes natural such as lava tubes, and unnatural such as ice tubes on the grounding line of a ice slab such structure could be built as well.

Sorry, here I go. If you made your structures like link sausages on the surface, then you could put low pressure transparent films over them to capture solar energy as heat into the building itself. Useful, but not critical to usage.

If you went a step further you might make an environment inside that plastic enclosure that would just allow cyanobacteria to grow and produce Oxygen. It would still be a solar thermal collector.

Perhaps only sun facing surfaces would have such transparent tenting over them.

While the heating may be marginal, heat pumps may be able to extract heat to produce industrially useful heat sources.

Link Sausage images:
https://www.bing.com/images/search?q=Li … C3&first=1
The spirals are an interesting idea, you could keep adding extensions to the structure.

Small passages could link the links to each other.

Again, I apologize if I mess up your good work.

Done

Last edited by Void (2024-01-10 09:15:52)

Calliban · 2024-01-10 09:26:35

Void, I hadn't thought of that. We could actually put thin polymer films over the top of the overburden. These would reflect radiated infrared light keeping the interior of the domes warmer. As the films don't have to be pressurised, they can be thin. I suspect dust accumulation would screw this up quite quickly. But if the films are thin, they may be cheap enough to replace quite often. Kind of like cling film. This stuff would die quickly due to UV light and dust abrasion. But if it is micron thin and costs pennies, then it doesn't matter. You just replace it every year.

As a cover for algae ponds: As basalt is a ceramic, large members would be vulnerable to brittle fracture under tension. But it would stand up to tensile loads a lot better than concrete would. We could produce pressurised domes with polymer linings. The polymer can be thin, because it is transfering tensile load to the members of the dome. Members will only fail catastrophically, if cracks exceed a critical length. So something like this could work.

tahanson43206 · 2024-01-10 09:41:32

For Calliban re interesting new topic...

While your focus is on Mars, where this material looks attractive for construction, I'm curious to know if there might an application on Earth.

As it happens, I've been thinking about how to make barges in regions on Earth where iron is rare.

Do you think that basalt might be suitable for such an application? The wall of a barge would be under compression. Would it be water tight?

Is there a limit to the size of a casting?

For evaluation, please consider a river barge, such as

https://www.google.com/search?q=show+im … ver+barges

(th)

Calliban · 2024-01-10 09:41:34

Looking at geodesic domes.
https://mygeodome.com/geodesic-dome-faq/

The tricky thing about building a dome from a single repeatable element is the interface joints where the elements meet at the corners of each triangular face. If the elements are shaped to a good tolerance, then we can glue them together with epoxy adhesive. If they are cruder, we would need to slot them into eyes where they interface, as shown in the images in the link. The epoxy glue idea is my favourite. We would support the elements at each corner using steel jigs until the glue hardens. At the bottom, where the elements of the dome transfer load into the ground, we need concrete plinths. The elements can again be glued into the concrete plinths.

Calliban · 2024-01-10 09:51:01

tahanson43206 wrote:

For Calliban re interesting new topic...
While your focus is on Mars, where this material looks attractive for construction, I'm curious to know if there might an application on Earth.
As it happens, I've been thinking about how to make barges in regions on Earth where iron is rare.
Do you think that basalt might be suitable for such an application? The wall of a barge would be under compression. Would it be water tight?
Is there a limit to the size of a casting?
For evaluation, please consider a river barge, such as
https://www.google.com/search?q=show+im … ver+barges
(th)

TH, people have cast river barges out of concrete in the past, so I see no reason why a basalt barge cannot be built. It doesn't need to be cast as a single shape. We can use adhesives like epoxy resins to bond basalt structural components together. The material has extremely high tensile strength. So bonding ceramic surfaces would appear to be practical.

Calliban · 2024-01-10 09:57:35

This reference looks at the possibility of welding cast basalt members
https://www.sciencedirect.com/science/a … 9523006873

A weld strength of 12.5MPa is reported. That is about half as strong as regular concrete. Epoxy resin has tensile strength 26 - 80MPa. But epoxy can take hours to harden and the low temperatures on Mars are a complication.
https://www.engineeringtoolbox.com/youn … d_417.html

We could weld the edges of elements using a CO2 laser. This is a common industry laser used for cutting metals. So it is well developed for this type of application. We would slot the elements into a steel jig that holds them at the correct angle. We then melt the basalt element members together using the laser. The joint will radiatively cool in seconds. So this process can be very rapid. Using laser welding, we could assemble a 50m dome very quickly.

Last edited by Calliban (2024-01-10 10:06:27)

Void · 2024-01-10 10:01:57

All of this is looking very wonderful.

I have for a long time wanted to figure out how to embed habitation in ice and to have comfortable temperatures inside and yet not melt the ice to a level of damage to the structure. I think you have provided some of what I need.

My ice mining notions are for the most part to mine ice by evaporation or melting at the ground line of ice slabs.

Building your basalt structures inside of those tubes, then I suggest that you would send water vapor back into the void between the basalt structure and the hollow of the ice, filling the hollow in with frozen Vapor>Solid ice.

We can indeed also use your plastic sheets to help ensure air tightness.

Then the pressurized space can have tents put into it, I say tents but they may be of strong insulation. Then air fed heat pumps can pull excess heat out of the space under the basalt structure and above the tenting, and push the heat into a liquid medium in piping, probably inside the tent.

Then the liquid medium could be used to heat the interior of the tents. Any excess heat could be piped away, perhaps to an industrial process or a surface greenhouse, or just dumped outside by some means.

The point is that by mining your water supply and then filling in "Some" of the tunnels in this manner you make pressurized space, using your basalt concepts and a few other things.

A whole network of pressurized space could be established at the mid and high latitudes on Mars.

Done

Last edited by Void (2024-01-10 10:07:38)

Calliban · 2024-01-10 10:16:18

Void wrote:

All of this is looking very wonderful.
I have for a long time wanted to figure out how to embed habitation in ice and to have comfortable temperatures inside and yet not melt the ice to a level of damage to the structure. I think you have provided some of what I need.
My ice mining notions are for the most part to mine ice by evaporation or melting at the ground line of ice slabs.
Building your basalt structures inside of those tubes, then I suggest that you would send water vapor back into the void between the basalt structure and the hollow of the ice, filling the hollow in with frozen Vapor>Solid ice.

Kim Stanley Robinson explored the idea of building a base under the Martian polar ice sheets in his Mars trilogy. I think it is certainly possible at the polar regions and at Korolov crater. Ice has a compressive strength of about 1MPa close to its freezing point. So there is a limit to the practical size of ice caves. But once you have a pressure containing tunnel, you can build thin walled structures within it and maintain a temperature differential using insulation. So in places where there is plenty of ice, this is definitely something we could do. We are going to need pressurised structures on Mars for maintaining vehicles and rockets. These don't neccesarily need to be heated above freezing. But it would be handy if they could be pressurised with breathable air.

Void · 2024-01-10 10:39:31

There are fossil ice sheets in the temperate areas down to the equivalent of Kansas, that are substantially thick.

https://www.science.org/doi/10.1126/science.aao1619
Image Quote:

It would be easy to build housing in these tubes, where you could be warm, and an electric heat suit would make things better also.

But by mining minerals below the ice in places, and also by tunneling into sedimentary rocks, lots of pressurized habitat that would be well heated would be possible.

And you could have riser houses that would have elevators in them that lead down to the tunnel system from the surface.

On the surface you could have solar type items like greenhouses.

https://www.cbsnews.com/news/ice-sheet- … d-on-mars/
Quote:

In this case, there was ice - and lots of it. Beneath the surface, they discovered an enormous slab of water ice, measuring 130 feet thick and covering an area equivalent to that of California and Texas combined. The ice was the result, the authors wrote, of snowfall "which can most easily explain the thickness and widespread nature of the excess ice observed."

Quote:

But Bramson and her colleagues were taken aback to find ice at the planet's mid-latitudes, analogous to earthly latitudes falling between the Canadian-U.S. border and Kansas, is something new.

So, except for dust storms you would have some sunshine even in the winters. Rough guess is 8 to 16 hours each day.
So, although nuclear is desired, solar can also be utilized year around, (Except Dust Storms).

130 feet is about enough for 100 mbar pressure, but there is berm on top of that. Perhaps 1/3 to 2/3 bar may be possible in enclosures, probably 2/3 preferred.

Done

.

Last edited by Void (2024-01-10 10:54:18)

Calliban · 2024-01-10 10:57:00

How plastic wrap is made.
http://www.madehow.com/Volume-2/Plastic-Wrap.html

Cheaper plastic wrap is polyethylene, which will be the easiest polymer to make on Mars. Plastic wrap is made by melting polyethylene graduals at 100°C and then extruding it between rollers.

When the cast basalt frame of our geodesic dome is made, we could wrap it in multiple layers of plastic wrap. The whole structure can then be covered, first with a layer of fine regolith and then with heavier rocks. The polymer wrap only needs to be strong enough to resist the weight of the overburden between the elements of the dome. So a thin layer less than 1mm thick should suffice. Alternatively, we could cover the dome structure with compressed regolith or cast basalt tiles before heaping overburden across it. The advantage of polymer wrap is that it is a thin and lightweight material. This makes handling it much easier.

Last edited by Calliban (2024-01-10 11:04:22)

Calliban · 2024-01-10 11:15:25

Cast basalt can withstand temperatures up to 350°C and is highly corrosion resistant.
https://amitengineeringsystems.com/cast … tings.html

I wonder if we could use basalt lined carbon steel for steam pipework? Carbon steel has been used, but suffers from high corrosion rate. Stainless steel is expensive. Basalt lined carbon steel appears to be a low cost option. But it won't stand up to pressure and temperature cycles very well. It would be OK for a plant that is intended to run baseload and won't be going through many thermal and pressure transients in its life. That would be the case for a nuclear powerplant secondary side, which would only power down once a year for fuel shuffling.

It might also be the case for nitric and sulphuric acid manufacturing plants. This plant needs to stand up to very corrosive environments. Nickel alloys work well, but cost a fortune. Usually the solution is to use stainless steel and live with the fact that corrosion will limit life. Basalt would be a lot cheaper than stainless steel. We are going to need a lot of chemical plant on Mars that operates at high pressure and high temperature. If we can make it out of basalt coated carbon steels, it will be a lot cheaper. But it would require more careful control of pressure and temperature transients. That means amongst other things, a reliable source of power. We want equipment that gets up to pressure and temperature, runs at steady state and rarely if ever shuts down. In that environment, ceramic linings could work.

Last edited by Calliban (2024-01-10 11:20:47)

Void · 2024-01-10 15:48:53

Well, you have started something new.

I wonder about Mars sand dunes. Could you make structures inside of them, Use the dune materials for the basalt, and then stabilize the dunes so that they do not travel in the wind anymore.

Mars sand dune images: https://www.bing.com/images/search?q=ma … RE&first=1

https://www.reddit.com/r/nasa/comments/ … curiosity/
Image Quote: csh1wgd7kk541.jpg?width=640&crop=smart&auto=webp&s=41a3b488a61f1bc6004ba1787deb8bcd5acf78ad

Done

Last edited by Void (2024-01-10 15:53:20)

Calliban · 2024-01-10 16:14:17

Those black sands look like they are rich in iron oxides, probably a mixture of +2 and +3 oxidation states and some partial states inbetween. It should be excellent feedstock for cast basalt. The strongest engineering bricks are made from iron rich clays and are baked in a reducing environment, with lots of CO present in the oven.
https://en.m.wikipedia.org/wiki/Staffor … blue_brick

I don't know the exact chemistry, but as the iron is progressively reduced, its oxides forms longer chain molecules which bind the ceramic grains into an extremely strong and hard brick. Bricks of this type were used in the foundations of the Empire State building. I wonder if we could do something similar with cast basalt? We would use a lance of some kind to blow carbon monoxide through an iron rich molten basalt, before pouring it into its molds. This should create an even stronger ceramic material than the basalt. The material would be reinforced by reduced iron oxides.

Thinking about some of the structures we could make with this cast material, it occurs to be that the Nissen hut would be an easy shape to build.
https://en.m.wikipedia.org/wiki/Nissen_hut

It can be constructed from a mixture of arc and beam shaped cast basalt members. These would be either bolted, glued or dowelled together into a semicircular frame. A polymer sheet can then be pulled over the top and anchored to the ground with stakes. Loose regolith would then be heaped over the top, providing overburden. The ends would be sealed by heaping regolith berms against them.

The cast basalt has enormous compressive strength and the cross bracing provided by latteral beams eliminates buckling instabilities. So it should be possible to build these soil covered structures to enormous sizes. There are no engineering limits to length. By building them side by side, arbitrary areas of surface can be enclosed. We could build entire cities under these semicylinder structures.

Last edited by Calliban (2024-01-10 16:33:40)

SpaceNut · 2024-01-10 19:53:56

Interesting to use a cast tile for a geodesic dome style construction as one could even make the frame where the tiles would set into from the same materials.

tahanson43206 · 2024-01-10 19:59:25

For SpaceNut ... It might be good to have a topic devoted to geodesic domes ....

I'd like to toss out a request for someone to dive into the mathematics a bit...

It's been a while since I read about these structures, but my recollection is that they are not cookie cutter designs.

It might look as though all the sides of the triangles are the same, but I have a vague recollection they are not.

(th)

Void · 2024-01-10 20:41:02

This is a very good topic!

Calliban, I am going to beg your permission to borrow. I want to do my under-ice thing, and don't want to gum up your works by getting you off course, as I expect you have a vision which you may expend here. So, let me know if you object me borrowing to another topic.

I will be observing your work here then.

Done

tahanson43206 · 2024-01-11 08:50:58

For Calliban re Basalt ...

Out of curiosity ... is the material that flows from a volcano a form of basalt, or is it different in some way?

I ask because (at least on earth) it would seem feasible to make useful shapes out of flowing lava.

The material would be hard to work with, no doubt, but if forms were laid in the path of a flow, then the forms would presumably fill up with material.

It might be challenging to collect the harvest, but perhaps this question will stimulate some creative thinking in this topic.

Question: Why has no one, in the history of Planet Earth, tried to make useful shapes out of flowing lava?

Or perhaps they have, and I just don't know about it?

Per Google:

Basalt is a type of lava that is more mafic. Mafic is defined as being rich in dark-colored minerals, such as pyroxene and amphibole. This is in contrast to felsic lavas, which are rich in silica and feldspar minerals. Magma is another term that is used to refer to molten rock.
Sep 14, 2015
Basaltic Lava Overview, Characteristics & Examples - Study.com
study.com › ... › Fundamentals of Minerals & Rocks

Follow up question: is "manmade" basalt a possibility? Can the ingredients be heated and poured into a mold?

Answer: Post #1 covers that exact subject. The answer would appear to be yes.

(th)

tahanson43206 · 2024-01-11 09:04:48

For Calliban .... this post is an extension of #18

A basalt block production line could be set up on the slopes of a Hawaiian volcano ...

Heavy machinery operated by teleoperation would place metal containers in the path of a lava flow.

As quickly as the containers fill they would be replaced with empty ones, and the filled containers would be delivered to the ocean for cooling/quenching.

The cooled containers would then be stacked on waiting barges for shipment to construction sites.

(th)

Calliban · 2024-01-11 11:05:39

I suppose it is possible to directly tap magma before it reaches the surface. This can then be injection molded to make building blocks. It woukd save a lot of energy using rock that is already molten. The main issue I can see is that this would mean building a factory close to the caldera of an active volcano. Not a popular place to live, with all those toxic gases and bad smells.

tahanson43206 · 2024-01-11 11:33:45

For Calliban re #20

Thank you for taking up the idea of tapping the caldera .... Teleoperation is coming along nicely.

It would be the clear answer for operations as you described.

What is the market for frozen magma? Is the material free of radiation? I have no idea. Granite is reported to have a radiation component that needs to be accepted by home owners who invest in the material.

The blocks can be large enough for large buildings built according to plans from thousands of years ago. The structures so built should last for a while.

I wonder how the cost would compare to quarried and shaped rock,?

(th)

Calliban · 2024-01-11 17:06:19

This link is to a site selling granite slab patio tiles.
https://www.stonepavingdirect.co.uk/pro … -900-x-600

An area of 18.5m2 and 20mm thick, selling for £450, which is a tad under $550 for about 1m3 of sliced stone. Pricey.

Whilst the energy requirements of cutting stone are modest and probably lower than cast basalt, high quality stone isn't available everywhere. It needs to be free from fractures and other discontinuities. From what I have seen of quarrying, it is quite a labour intensive operation when precision stone blocks are needed. Amorphous stone is strewn across the surface on Mars. But finding blocks that can be fashioned into structural components may be more challenging. Stone is always aesthetically more pleasing. If we want to build beautiful and long lasting interiors on Mars, then stone is the way to go. The other useful attribute of underground stone mining on Mars, is that excavated volumes can be used as habitation space. So we don't just use the stone itself, but the hole left behind.

One way of reducing the cost of making stone blocks would be to employ robotic cutting machines. The machines would be guided by a computer programme that has a list of desired shapes and sizes. Stones are gathered from the surface of Mars and delivered to the machine. Each stone is scanned, its geometry and size recorded. The machine then decides which of the desired shapes the stone is best fit for and cuts it accordingly. If we had a machine like that, we could make use of surface rocks. We could even combine both approaches and put offcuts into the basalt melter.

Basalt has specific heat of 0.84KJ/kg.K and density 3000kg/m3. Heating 1m3 of basalt from 0°C to its approximate melting point of 1250°C, would require some 3.15GJ of heat (~900kWh). Each kWh of electricity costs about $0.1 on average. So melting a cubic metre of basalt takes about $90 worth of electricity. That is a lot cheaper than $550. But a true cost comparison needs to compare capital, labour, energy and other operating costs. The cheaper power is, the more sense it makes to gather amorphous rock or sand and melt it into the shapes we want. I think the best option on Mars will depend upon what happens to be available at the specific site.

Last edited by Calliban (2024-01-11 17:24:10)

Void · 2024-01-14 13:13:49

I have wanted to make the point that the heat from the Cast Basalt might be reused for some other purpose.

Done

New Mars Forums

Announcement

#1 2024-01-10 08:29:32

Cast Basalt

#2 2024-01-10 09:03:51

Re: Cast Basalt

#3 2024-01-10 09:26:35

Re: Cast Basalt

#4 2024-01-10 09:41:32

Re: Cast Basalt

#5 2024-01-10 09:41:34

Re: Cast Basalt

#6 2024-01-10 09:51:01

Re: Cast Basalt

#7 2024-01-10 09:57:35

Re: Cast Basalt

#8 2024-01-10 10:01:57

Re: Cast Basalt

#9 2024-01-10 10:16:18

Re: Cast Basalt

#10 2024-01-10 10:39:31

Re: Cast Basalt

#11 2024-01-10 10:57:00

Re: Cast Basalt

#12 2024-01-10 11:15:25

Re: Cast Basalt

#13 2024-01-10 15:48:53

Re: Cast Basalt

#14 2024-01-10 16:14:17

Re: Cast Basalt

#15 2024-01-10 19:53:56

Re: Cast Basalt

#16 2024-01-10 19:59:25

Re: Cast Basalt

#17 2024-01-10 20:41:02

Re: Cast Basalt

#18 2024-01-11 08:50:58

Re: Cast Basalt

#19 2024-01-11 09:04:48

Re: Cast Basalt

#20 2024-01-11 11:05:39

Re: Cast Basalt

#21 2024-01-11 11:33:45

Re: Cast Basalt

#22 2024-01-11 17:06:19

Re: Cast Basalt

#23 2024-01-14 13:13:49

Re: Cast Basalt

Board footer