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usarender
millennium club
Joined: 01 May 2004
Posts: 1258
Location: San Diego, Ca
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 Posted: Fri Dec 07, 2007 3:47 pm Post subject: Building with Earth |
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Building with earth
A material for the future
Building with earth is definitely an appropriate and cost & energy efficient technology that has a great future. However, one has to master the disadvantages of the material. These are usually caused by variations in the soil quality, and hence the block quality may suffer. Bad quality soil can give relatively poor characteristics (when compared to concrete) and shrinkage cracks may occur.
Among the advantages of earth as a building material, one observes:
*Earth is a local material, contributing to sustainable development.
*Production of the building components utilises a lot of semi-skilled manpower.
*The technology is easily adaptable and transferable.
*The energy & monetary costs are much lower than with most other materials.
*The thermal comfort and 'vibratory' atmosphere are very positive.
Obviously, one has to master the materials and techniques so as to obtain the optimum possibilities with a harmonious, durable, agreeable and efficient architecture!
Nevertheless, the following drawbacks have to be considered:
*Mechanical qualities less regular.
*Sensible building details.
*Constraint to organize and manage the production of one's own building material on the site.
Challenge
Building with earth has a great past, but also a promising future, especially in Auroville. It is a true challenge to realize an architecture full of light, suppleness, simplicity, imagination and beauty with a dark, heavy and formless mud. |
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usarender
millennium club
Joined: 01 May 2004
Posts: 1258
Location: San Diego, Ca
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| Posted: Fri Dec 07, 2007 4:04 pm Post subject: Rammed Earth in Green Building |
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Rammed Earth Construction
Made from sand, quarry by-products and clay, combined with virgin cement or fly ash soils, earth construction results in beautiful, energy efficient, durable, non-toxic structures which incorporates remarkable thermal and acoustic properties. With its roots in ancient building techniques, modern earth construction is currently seeing its re-emergence as a valuable building technique. Earth construction is a highly specialized process, however, and care must be taken to insure that the finished product meets all specifications, both structural and aesthetic. Not all sites are appropriate for earth construction; extensive site and soil analysis must be performed before initiating a rammed earth building project.
Rammed earth in green building
Rammed earth structures are beneficial for natural building because they can utilize locally available materials with little embodied energy and harmful waste. Earth is a widely available building material with virtually no side effects associated with harvesting for use in construction.[1] The earth used is typically subsoil, leaving topsoil readily available for agricultural uses. Often the soil can be used on the site where the construction takes place reducing cost and energy used for transportation.[1] It is also affordable to build with, as the materials are inexpensive or free. It is a viable building material for low- income builders with help from unskilled workers, friends, or family. Today more than 30 percent of the world's population uses earth as a building material.[2]
Rammed earth buildings reduce the need for lumber because the forms used are removable and can then be reused for different rammed earth wall construction.[3] The forms are usually made of reinforced plywood, but sheet metal or even glass fiber can be used. The form wall faces must be externally reinforced with laterally running beams to prevent outward bending of the wall faces during the compression process. The two opposing wall faces must be clamped together and the wall edges need to be securely compressed between the form faces to withstand the high amounts of pressure created during compression.
The USDA observed that rammed earth structures last indefinitely and could be built for no more than two-thirds the cost of standard frame houses. Rammed earth can carry a heavy load and using re-bar, wood or bamboo reinforcement can prevent failure caused by earthquakes or heavy storms. Mixing cement with the soil mixture can also increase the structure's load bearing capacity. The compression strength of rammed earth can be up to 625 pounds per square inch. This is only two-thirds the value of a similar thickness of concrete, but a rammed earth building is still a useful durable material.[2] Termites won’t infest rammed earth walls and the material is reusable, biodegradable and highly fire resistant. The walls require no toxic treatments and have no risk of off-gassing toxic fumes, making it ideal for chemically sensitive dwellers.[4] Properly built rammed earth can withstand loads for thousands of years as the history of rammed earth structures around the world has proven.[5] Stucco can finish the walls in almost any color or style; untouched the walls have the color and texture of natural earth. Blemishes can also be patched up using the soil mixture as a plaster and sanded smooth.Rammed earth is not only an economically viable construction technique, it results in pleasant, and energy-efficient buildings. The density and thickness of rammed earth makes it so that hot or cold temperature penetration has a slow rate of thermal conductivity. Warmth takes almost 12 hours to work its way through a 14 inch thick wall.[citation needed] The walls provide good thermal mass, which helps keep indoor temperatures stable, particularly in regions with dramatic daily temperature changes. The half-day rate of heat transfer and thermal mass of the material makes rammed earth a practical material for passive solar buildings. Rammed earth has been a popular choice for buildings where temperature fluctuations need to be kept to a minimum. It can be used in cooler climates but must be protected from heavy rain and insulated with vapor barriers.[5]
Typically rammed earth walls are about 12 to 14 inches thick making them ideal for humidity control and noise barriers from traffic, furnaces, compressors, fans or ducts. Rammed earth also allows more air exchange than concrete structures allowing the building to breathe and not become clammy without significant heat loss as the material mass absorbs the temperature as the wall breathes.[2]
By its very nature, Earth is one of the best sustainable building materials as it is historically the longest used material by man. It is universally a naturally available product, with a heavy thermal mass and a natural barrier to cold winds and forces of nature including insects and rodents. The material is not rationed or monopolized, is fire proof, and sound proof.[2] Rammed earth can contribute to a solution for much of the world of homelessness caused by high costs as well as today ecological dilemma caused by deforestation and toxic building materials. |
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ahmeds
Joined: 15 Sep 2007
Posts: 128
Location: UAE
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| Posted: Sat Dec 08, 2007 4:37 am Post subject: |
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That is a very nice article and with good information but I have one question.
b]The walls require no toxic treatments and have no risk of off-gassing toxic fumes, making it ideal for chemically sensitive dwellers[/b]-usarender
So does it mean that structues won't need anti termite treatment at all even at foundation level or it will reduce the quantity of anti termite materials to be applied. I didn't understand this properly. |
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usarender
millennium club
Joined: 01 May 2004
Posts: 1258
Location: San Diego, Ca
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| Posted: Sat Dec 08, 2007 11:12 am Post subject: Rammed Earth and Termite Protection |
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Hello Ahmeds,
The answer to your question can be found here -->>
Frequently Asked Questions
| Quote: | | We have termites on our property. Why are the Rammed Earth walls termite resistant? |
""Due to the materials and construction method, SRE walls are deemed 'termite resistant' under the Building Code of Australia. When built on a concrete slab, termite protection is required only around pipe work penetrating the slab area, reducing costs associated with termite proofing a dwelling"" |
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ahmeds
Joined: 15 Sep 2007
Posts: 128
Location: UAE
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| Posted: Sun Dec 09, 2007 2:48 am Post subject: |
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| understood, I actually wanted clarification it is alright I agree on that. I asked that because that problem of termites is common in some parts of Kenya and here in UAE anti-termite treatment is also recommended and widely used, though they use different materials. |
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Antisthenes
Joined: 28 Nov 2006
Posts: 756
Location: Phoenix
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| Posted: Mon Dec 10, 2007 10:16 am Post subject: |
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I have built with Earth(self made Adobe) on many projects. good to see a Palo Solari style building in the picture on the site, Arcology with earth makes way more sense.
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The most necessary/useful piece of learning is that which unlearns what is untrue: 'evil'
may be acquired, Happiness through virtue which is based on knowledge!/? |
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