Description and Construction of Adobe
– Adobe bricks are rectangular prisms that air dry individually without cracking.
– They can be assembled by applying adobe mud to bond the bricks.
– There is no standard size, with variations in different regions.
– Popular sizes range from 8 by 4 by 12 inches to 10 by 4 by 14 inches.
– Larger sizes can reach up to 100 pounds and are difficult to move, resulting in a different construction method known as rammed earth.
– Poured and puddled adobe (cob) is made by placing soft adobe in layers, rather than making individual dried bricks or using a form.
– The introduction of holes in the ground as forms and later wooden forms by the Spanish changed the method of building with adobe.
– Cuarenta Casas in Mexico is an example of cliff dwellings made with poured or puddled adobe.
Strength and Durability of Adobe
– In dry climates, adobe structures are durable and some of the oldest existing buildings.
– Adobe buildings have greater thermal mass, offering significant advantages.
– However, they are susceptible to earthquake damage if not reinforced.
– Examples of earthquakes causing damage to adobe structures include the 1976 Guatemala earthquake, the 2003 Bam earthquake, and the 2010 Chile earthquake.
– Adobe walls are load-bearing and must have sufficient compressive strength.
– Building codes require a minimum compressive strength of 300lbf/in for adobe blocks.
– Adobe construction should avoid lateral structural loads that cause bending.
Distribution and History of Adobe
– Adobe buildings made of sun-dried earth are common worldwide.
– Indigenous peoples of the Americas have been using adobe for thousands of years.
– Puebloan peoples transitioned from using handsful or basketsful of adobe to making bricks.
– Adobe bricks were also used in Spain from the Late Bronze and Iron Ages.
– The wide use of adobe can be attributed to its simplicity, design, manufacture, and economics.
– Adobe construction faced restrictions in the United States due to building codes and seismic requirements.
– Post-and-Beam adobe and veneers are still being used in California.
Composition and Material Properties of Adobe
– Adobe bricks are made of earth mixed with water and an organic material like straw or dung.
– The soil composition typically contains sand, silt, and clay.
– Straw or dung helps bind the bricks together and prevent cracking.
– The ideal soil texture for adobe is 15% clay, 10-30% silt, and 55-75% fine sand.
– Modern adobe is stabilized with emulsified asphalt or Portland cement.
– Adobe acts as a significant heat reservoir due to its thermal properties.
– The high thermal mass of adobe moderates temperature fluctuations in desert climates.
Adobe Roof and Other Structures
– Traditional adobe roofs are constructed using a mixture of soil/clay, water, sand, and organic materials.
– The roof can be assembled using wood or metal beams as a framework for layering adobe bricks.
– Flat adobe roofs are functional only in dry climates without snow loads.
– Vigas (heaviest wooden beams), latillas (smaller members), and brush are used in traditional flat adobe roofs.
– An adobe mortar layer is recommended between bricks on the roof for strength and moisture barrier.
– The largest structure ever made from adobe is the Arg-é Bam built by the Achaemenid Empire.
– The Huaca del Sol in Peru has 100 million signed bricks, making it one of the largest adobe structures.
– Chan Chan and Tambo Colorado are ciudellas in Peru made of adobe. Source: https://en.wikipedia.org/wiki/Adobe
Adobe (/əˈdoʊbi/ ⓘ ə-DOH-bee;Spanish pronunciation: [aˈðoβe]) is a building material made from earth and organic materials. Adobe is Spanish for mudbrick. In some English-speaking regions of Spanish heritage, such as the Southwestern United States, the term is used to refer to any kind of earthen construction, or various architectural styles like Pueblo Revival or Territorial Revival. Most adobe buildings are similar in appearance to cob and rammed earth buildings. Adobe is among the earliest building materials, and is used throughout the world.
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Adobe architecture has been dated to before 5,100 BC.
