Jun
Poured earth is a very similar technique to concrete. The primary difference is that it uses ordinary soil as aggregate instead of sand or gravel. Poured earth also uses Portland cement as a binder, but it generally uses much less. It can be considered a moderate strength concrete. Minimal maintenance is required on a poured earth structure since it has very high resistance to the weather.
The ideal soil is low in clay, and somewhere between silt and three-eighths inch aggregate. Testing needs to be done on the material to assure the quality of the product. It must be tested for shrinkage and compression strength. The mix needs to have little or no shrinkage in the drying process, and it needs to have compressive strength of 800 to 1200 psi.
Poured earth buildings have an added benefit of being capable of having a steel insulating grid within the wall. This increases the thermal mass and overall strength of the structure. However, because of iis rather customized nature, a poured earth house is usually ten to twenty percent more expensive than traditional construction.