Alternative House Foundations
- Cement"Concrete" is Copyrighted by Flickr user: shaire productions (Sherrie Thai) under the Creative Commons Attribution license.
According to the Portland Cement Association (PCA), four principle kinds of cement are made from supplementary cementitious materials (SCMs). These materials are fly ash, ground granulated blast furnace slag (or slag cement), silica fume and natural pozzolans. - In the electrical power sector, fly ash is produced from the burning of coal in traditional power plants. This fly ash can be recycled under the classifications of Type C and Type F. Concrete can easily be mixed with fly ash to produce a dense and sustainable building mixture that can be poured into a home foundation.
- The steel industry creates slag when iron ore is melted down to iron in the blast furnace. The slag in the furnace is cooled with water, refined, dried and crushed into a powder. This power can be mixed into cement as a hydraulic component. It gives more strength to concrete, creating a material that is less permeable, stronger and resistant to chemical seepage.
- According to the U.S. Department of Transportation, silica fume, or microsilica, is created when high-purity quartz is reduced in an electric furnace in the process of making silicon and ferrosilicon alloys. Although the silica fume additive to concrete is not a commonly used SCM according to the Portland Cement Association, this material may be available as an alternative to slag cement or fly ash. The homeowner can request a foundation poured of silica fume if it is available to the local concrete masonry contractor building the home.
- Homeowners may not know that making cement for building homes and other structures is bad for the environment. According to Ronald A. Harris, Thomas D. Eatmon, Jr., and Christian W.A. Seifert, cement creates particulate matter and carbon dioxide, which are harmful to humans. The authors recommend using natural pozzolans to mix cement for sustainable housing with the natural earth materials of diatomaceous earth, rice husk ash and volcanic ash. These materials can be harvested from local sources and mixed into concrete for home foundations and walls.
