Compressed Earth Blocks

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CEB

CEB - Compresssed Earth Block - regarded as the highest quality natural building method; also used in upscale housing; does not require curing - so may be built continuously; lends itself to 100% onsite building material sourcing; excellent thermal, acoustic, and strength; aka structural masonry.

Also usable in fences, cisterns, road paving, Usable for ovens in a bakery, pond dams, thermal storage cisterns, silos. Used for barns, dairy plant, bakery building, additinal housing, greenhouses, etc. I would go so far as that could be the secret weapon of the entire operation. Other connections in diagram: requires soil to be pulverized, which may be done with the agricultural spader. May be used for building raised beds, modular building and greenhouse units. High value flex fab enterprise opportunity for any entrepreneur interested in fabrication of machine- huge profits are possible, because other CEB presses are expensive ($25k for one of 3-5 brick/minute performance). Livelihood opportunity for independent builders. Requires as little as 1 person to operate. OSE design is based on power from tractor hydraulics - where the tractor is a general tool that can supply power to a large number of devices. Output with 2 people - a 6 foot high round wall, 20 feet in diameter, 1 foot thick, can be built in one 8 hour day.

What a CEB brick is made of

Soil mix conditions: The soil mix is 15-40 percent non-expansive clay, 25-40 percent silt powder, and sharp sand to small gravel content of 40-70 percent. The more modern machines do not require aggregate (rock) to make a strong soil block for most applications. Soil moisture content ranges from 4 to 12 percent by weight. Clay with a plasticity index (PI) of up to 25 or 30 would be acceptable for most applications. The PI of the mixed soil (clay, silt and sand/gravel combined) should not exceed 12 to 15; that is the difference between the Upper and Lower Atterberg limits, as determined by laboratory testing.

CEB Shapes and Sizes

(TODO: Add pictures of CEBs built with The Liberator; show different shapes and sizes it can make)

Alternative Materials

• Krafterra: A researcher from UnB (University of Brasília, Brazil) suggests the use of kraft paper from cement bags mixed with earth to obtain better CEBs, dubbed krafterra.
• Wool
• Geopolymers: Although cements are the most common application of geopolymerization, a range of refractory and structural products have been produced. The products of geopolymerization are called poly-silicates.

CEB Press Fabrication

Fabrication is simple - after metal is cut - a drill press is required for drilling holes for design-for-disassembly structure. Welding is required in a few places where bolting is not practical, such as the hopper box. Summary: a high performance, rapid, semi-skilled building technique, which lends itself as a building method for creating advanced civilizations. Lifetime design.

More Information

• Blog post on the full product release of The Liberator, the open source, high performance CEB press
• The Liberator Full Product Release
• CEB Press
• Earthquake safety
• CEB FAQ from Instituto Tierra y Cal
• Overview of CEBs, by Jim Hallock
• What should we have in mind when acquiring a CEB press? CEB legal issues and norms in Brazil
• appropedia: Compressed earth brick press
• Auram earth construction equipment and blocks from Auroville Earth Institute (available in many shapes).

See Also

• Rammed Earth Construction from Autonopedia
• Rammed/Stabilized Earth from Green Building Encyclopedia