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Impaler

Member

From: South Hill, Virginia

Registered: 2012-05-14

Posts: 286

Stryofoam based Construction

Construction on the Martian surface will be necessary to support any kind of large growing population, I'd estimate that somewhere in the range of 100-1000 population on Mars their would be a transition from fully prefabricated habitats being brought from Earth to structures built from a mixture of low-tech Martian material and Earth sourced material.

The first Martian material will be bulk regolith, it can do several valuable things

Block Cosmic/Solar-flare Radiation
Block Ultra Violet Radiation
Provide Thermal Mass
Provide Insulation

To obtain the benefits of these properties the regolith needs to be used to cover the structure which imposes considerable compressive strength requirements on the structure, and compressive strength is the one thing the regolith lacks.  If a cementing process can be discovered then some compressive strength might be possible, but this cementation will likely require some material from Earth or a high energy input, or a high degree of site-specificness to employ. 

Alternatively a lightweight easy to use structural material from Earth could be used, it needs high compressive strength to weight and to be easy to ship and assemble.  Stryofoam offers one of the best choices for this structural material.  Styrofoam is made from polystyrene, a simple to make polymer that can be shipped as a LIQUID and turned into foam using simple machinery and water or CO2 as a blowing agent, the expanded beads can then be molded into nearly any shape and have an excellent strength to weight ratio that makes such foam a desirable building material here on Earth for road construction and for making forms for cement walls.  It may be desirable to extend the foam by mixing screened Mars aggregate or sand it it as well if this can reduce the amount of foam needed for any given structural application.

The general construction technique I foresee would begin digging a long trench several meters deep, line the floor of the trench with foam flooring and build vertical walls that are hollow and filled with regolith.  Once the walls are up to the original ground level back-fill around them and begin a barrel vaulted ceiling of arched foam blocks connecting the walls.  As the barrel vault is completed the excavated regolith from earlier is deposited on top of the structure to provide radiation shielding of at least 500 g/cm^3 which will be half the shielding found at Sea-level on Earth, this would be ~3 meters depth of regolith.  The open ends of the barrel vault are closed with double vertical walls with the same regolith thickness between to give a full encapsulation.  Penetrations through either the vault or the end walls provide access though they need to be kept small to maintain structural integrity.

Structures several hundred meters long and 30 meters wide, with floor to ceiling heights 20 m should be possible, internal volumes would be 500 m per meter of length so nominal 50,000 m^3 for a 100 m long building.  Inside of this structure thin plastic pressure envelopes would be expanded, possibly in a series of cells like a Zeppelin for redundancy, as the plastic is being protected from UV, thermal flux and micrometeorites is can be substantially thinner then any enveloped intended for outside usage on Mars, when combined with the high efficiency of large volumes the pressure envelope will be trivial in the total mass budget even if it masses 1 km m^3, a 10 ton monolithic bubble that can be transported to Mars would easily fill the whole structure.  Inside these cells an aluminum triangular truss is constructed from Earth delivered aluminum I-beams and upon this the flooring is attached to create a multistory living area, heavy equipment would naturally go only on the basement level with the rest being conventional living space.

Last edited by Impaler (2015-01-22 00:03:44)

SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,433

Re: Stryofoam based Construction

Insulation and gets harder with temperature drop...
I am sure we will make use of this in some form or another