| Technological Performance |
(Back to Soil Based Unit Masonry Home Page)
| Due to the lack of resources, specific information is not readily available for this system. |
| Structural/Mechanical Performance |
| Property |
Compressive Strength |
Modulus of Rupture |
| Unit(s) |
psi |
psi |
| Description of Property |
A measure of the material's ability to withstand loads. |
A test that measures the point at which the material fails. |
| Pertinent Test Protocols |
Knife Penetration Test: A common pocketknife is pressed into the side of the brick. The knife will not penetrate more than 1/8" if the brick is dry and properly made. |
Drop test: A brick is dropped on its corner from a height of 3 ft onto hard ground should suffer little damage. |
| Typical Range of Values |
300 psi minimum; 1,000-2,000+ psi possible with additives such as fly ash, emulsified asphalt, bitumen, and portland cement |
50 psi minimum |
| Codes/Regulatory Constraints |
New Mexico State Building Code Note Earthen Materials Building Code |
| |
Source: Alternative Construction. Lynne Elizabeth and Cassandra Adams. John Wiley & Sons: 2005. |
| Permeability Performance |
| Property |
Infiltration Rate |
Water Absorption Rate |
| Unit(s) |
mg/m2h Pa |
percent |
| Description of Property |
The vapor penetration through a 1 mm-thick layer |
The percent of water by weight absorbed by the material. |
| Typical Range of Values |
Approximately 2 mg/m2h Pa |
0.5-3 percent |
| |
Source: The Ecology of Building Materials. Bjorn Berge. Architectural Press: 2001. |
Source: Alternative Construction. Lynne Elizabeth and Cassandra Adams. John Wiley & Sons: 2005. |
| Indoor Air Quality Performance |
|
Structures built with soil-based masonry provide a pleasant indoor environment. "Because of adobe's absorption and desorption capacity, the relative humidity of a house interior (finished with mud plaster) is a steady 50% +/- 5%.
An added benefit of adobe earth-building materials is that they can be nontoxic. For those who are allergic or sensitive to modern processed materials and finishes, the healthful interior environment of a natural earthen home is a refreshing alternative. Moreover, through passave solar heating, options for fresh air exchange can be almost limitless, because the earth walls store and radiate heat to maintain an even, comfortable interior temperature."
|
| Source: Alternative Construction. Lynne Elizabeth and Cassandra Adams. John Wiley & Sons: 2005. |
| Thermal Performance |
| Property |
Thermal Conductivity |
Specific Heat Capacity |
| Unit(s) |
Btu hr/ft2 |
Btu/lb-°F |
| Description of Property |
A measure of the material's ability to conduct heat. |
A measure of the material's ability to store thermal energy |
| Typical Range of Values |
Adobe = 0.3 Btu hr/ft2 |
Adobe = 0.24 Btu/lb-°F |
| Codes/Regulatory Constraints |
New Mexico State Building Code |
| |
Source: Alternative Construction. Lynne Elizabeth and Cassandra Adams. John Wiley & Sons: 2005. |
| Durability Performance |
| Stabilizing adobe with emulsified asphalt "upgrades adobe construction by increasing its long-term durability through waterproofing, which greatly reduces swelling and shrinking. Fully stabilized abobe contains approximately 5 percent asphalt emulsion by weight." |
| Source: Alternative Construction. Lynne Elizabeth and Cassandra Adams. John Wiley & Sons: 2005. |
| Fire Performance |
| Soil-based unit masonry is essentially fire-proof, since soil does not burn. Adobe walls stabilized with emulsified ashpalt are even more fire resistant. |
| Source: Alternative Construction. Lynne Elizabeth and Cassandra Adams. John Wiley & Sons: 2005. |
Anybody who wants to create Low-Cost & High-Quality buildings that have an environmental impact would be a termed as a potential stakeholder likely to make a purchasing decision for Soil Based Unit Masonry Systems.
Earth Building systems are popular to the Buyers because of many reasons:
Ø The primary reason being that its resources are available in countries around the world. In many cases the material can be excavated on site.
Ø Self-building is a common practice because of the user friendly and relatively simple building construction methods.
Ø Energy conservation is an important aspect of earth building as it requires much less energy than a regular concrete building which in turn increases its life expectancy.
Ø The earth building materials are recycled more easily than other building materials.
Ø Good moisture regulating properties features create a better indoor climate than most materials.
Ø Fire proof materials imply belief from the user's perspective.
Reference:
The Ecology of Building Materials. Bjorn Berge. Architectural Press. 2001.
|
Function
|
Element
|
Mode
|
Cause
|
Effect
|
|
Structural
|
Adobe Brick
|
Cracking
|
Earthquakes
|
Durability of structure
|
|
Seismic Deficiencies
|
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Too much clay in adobe brick mixture
|
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Shrinkage after adobe brick dries
|
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Very wide door and window openings
|
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Too many windows
|
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Openings too close to corners in structure (less than 4’ from corners)
|
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Overweight roof
|
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Narrow walls
|
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Fragmentation
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Too little clay in adobe brick mixture
|
Strength and tension of adobe bricks and overall durability of the structure
|
|
Rapid surface destruction
|
High salt content in adobe brick mixture
|
Permeability and durability of structure
|
|
Decomposition
|
Substantial amount of organic matter in adobe mixture or structure foundation
|
Strength, moisture control, and durability of the structure
|
|
Low pH value of adobe brick mixture
|
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Burlap (Hessian) Earthbags
|
Deterioration of bag (more so than polypropylene)
|
Poor quality and lack of durability
|
Strength, Insulation, and Durability
|
|
Polypropylene Earthbags
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Deterioration of bag
|
Exposure to UV rays
|
|
Cavities within structure
|
Organic matter
|
Strength and durability of structure
|
|
Waterproofing
|
Adobe Brick
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Water and moisture damage
|
No eaves at base of walls and foundations
|
Durability, Cleanliness, and Strength of structure
|
|
Trapped water in cracks in walls
|
|
Location of structure in areas of standing water
|
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Flooding
|
|
Ground gradient not sloped
|
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Not existing or adequate roof overhang
|
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Earthbags
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Water and moisture damage
|
No waterproof membrane between tops o bags and bottom of bales
|
Durability, Cleanliness, and Strength of structure
|
|
Decay of bags
|
|
Wet environment/ conditions
|
|
Fire Performance
|
Adobe Brick
|
n/a
|
|
|
|
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Earthbags
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n/a
|
|
|
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Thermal Insulation
|
Adobe Brick
|
n/a
|
|
|
|
|
Earthbags
|
n/a
|
|
|
www.world-housing.et/uploads/adobe.pdf?pr=array
www.greenhomebuilding.com/adobe.htm
| Third Party Evaluation / Information Sources |
Back to top |
Listed below are three third-party sources that prove to be the "Best of the Breeds." These sources review, evaluate, and provide reliable information about plumbing vent systems. Each source has been checked for Credibility, Accuracy, Reasonableness, and Support using the CARS checklist.
Alternative Construction: Contemporary Natural Building Materials
The book examines a broad range of traditional and modern natural construction methods, including straw-bale, light-clay, cob, adobe, rammed earth and pisé, earthbag, earth-sheltered, bamboo, and hybrid systems. It also covers key ecological design principles, as well as current engineering and building code requirements.
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Credibility
|
The Authors' credentials are reliable and trustworthy. One is a consultant on sustainable community development and the other is an architect .
|
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Accuracy
|
Experts on each building system have discussed the overall scenario of the system making the book very accurate and exact. Published in 2005, the book is reasonably up to date.
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Reasonableness
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Presents a non-biased and fair analysis of alternative construction materials and their uses in the industry.
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Support
|
A whole list of references and citations have been used by the authors .
|
Peter J. Walker
Peter J. Walker is a Senior Lecturer, Dept. of Architecture and Civil Engineering, Univ. of Bath, Bath, UK. In the Sep/Oct 2004, he wrote an ASCE journal on "Strength and Erosion Characteristics of Earth Blocks and Earth Block Masonry."
Initially, the paper describes methods currently used for strength and erosion resistance testing of earth blocks. Following this, an experimental study undertaken to assess the influence of test procedure and specimen geometry on strength and erosion characteristics is presented. The experimental correlation between compressive and bending strengths is presented. Results of compression tests on masonry walls are also presented together recommendations for design. Finally, the influence of test method and specimen geometry on erosion resistance and the correlation with block strength is discussed.
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Credibility
|
ASCE Journals are very reliable sources of information. Ray Moore is a Senior Lecturer, Dept. of Architecture and Civil Engineering, Univ. of Bath, UK.
|
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Accuracy
|
Walker's article is very factual and up to date. The article was published in Sept/Oct of 2004. Peter Walker describes a detailed and comprehensive way to check the characteristics of earth blocks.
|
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Reasonableness
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His article shows no sign of bias; he does not take pre-conceived notions in account for his study. Instead, he reviews the characteristics of earth blocks in general.
|
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Support
|
A comprehensive list of references and cited articled have been provided by the author.
|
http://cedb.asce.org/cgi/WWWdisplay.cgi?0413135
ASTM International
ASTM International (ASTM), originally known as the American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services.
The paper on "Standard Test Methods for Moisture-Density Relations of Soil-Cement Mixtures" talks about determination of the relationship between the water content and the density of soil-cement mixtures when compacted before cement hydration as prescribed.
|
Credibility
|
ASTM International is one of the largest voluntary standards developing organizations in the world. ASTM standards are used by individuals, companies and individuals around the world.
|
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Accuracy
|
Though outdated(the paper was published in 1982),the points discussed in the paper still hold relevance and a complete analysis of the test methods used in soil-cement mixtures.
|
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Reasonableness
|
The paper is pretty much fact based so no conflict of interest or slanted tones arise in the paper.
|
|
Support
|
Referenced documents and indices have been provided along with the links to those documents so that the reader is assured of the support of the paper..
|
http://www.astm.org/DATABASE.CART/HISTORICAL/D558-96.htm
| The Adobe Association of the Southwest |
 |
|
www.adobeasw.com
|
| Headquartered in New Mexico, The Adobe Association of the Southwest is a voice within the earth building community working toward its mission statement: "To champion earth construction of yesterday, today, and tomorrow." Goals include sharing knowledge about building with earth and interacting with similar organizations to promote this construction method. The Association achieves its goals is by holding an annual membership meeting as well as a bi-annual conference. In May, the AdobeUSA 2009 Conference will be held in El Rito, NM. |
| Mason Contractors of America |
 |
| www.masoncontractors.org |
| Incorporated in 1950, the Mason Contractors Association of America (MCAA) represents masonry contractors and suppliers in national legislative and political affairs. MCAA's purpose is "to help educate, train, and represent the mason contractor through its various aiding members to maintain its competitive edge against other construction methods." In early February 2009, the annual MCAA Convention will be held in Las Vegas. |
| Virgnia Masonry Association |
 |
| www.virginiamasonry.org |
| The Virginia Masonry Association (VMA) "serves as a resource to builders, design professionals, and homeowners in the use of masonry as a superior option in construction and design." VMA's Apprenticeship Training Program offers education to those interested in learning the trade. Participants attend VMA classes once per week and gain experience by working daily with a member company. Upon completion, students are awarded a nationally-recognized certificate by the Virginia State Department of Labor and Industry. |
| Cal-Earth |
 |
| www.calearth.org |
| Founded in 1986 by renowned architect Nader Khalili, Cal-Earth (The California Institute of Earth Art and Architecture) is "a non-profit foundation dedicated to research and education of the public in environmentally oriented arts and architecture." Cal-Earth primarily focuses on earthbag construction, with many innovations resulting from years of research. "Superadobe," one particular system developed by Khalili, utilizes uncut polypropylene bags. Visit the website above for more information. |
| Sierra Green Building Association |
 |
| www.sigba.org |
|
The Sierra Green Building Association (SiGBA) works "to promote effective environmental design in our communities by: advocating resource efficiency in all phases of design, construction, and operation of homes and businesses; providing educational resources and support in the areas of site development, energy, building materials, air, water, and waste; and coordinating networking opportunities and community events." SiGBA is based in the Sierra region of California and Nevada.
|
| Sources: All information and logos from the website of the respective organization. |
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