Adobe

Adobe (/əˈdoʊbi/ (listen); Spanish pronunciation: ) (Arabic: الطوب‎, romanized: aṭ-ṭūb) is a building material made from earth and organic materials. Adobe is Spanish for mudbrick, but in some English-speaking regions of Spanish heritage, the term is used to refer to any kind of earth construction. 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. Adobe bricks are rectangular prisms small enough that they can quickly air dry individually without cracking. They can be subsequently assembled, with the application of adobe mud to bond the individual bricks into a structure. There is no standard size, with substantial variations over the years and in different regions. In some areas a popular size measured 8 by 4 by 12 inches (20 cm × 10 cm × 30 cm) weighing about 25 pounds (11 kg); in other contexts the size is 10 by 4 by 14 inches (25 cm × 10 cm × 36 cm) weighing about 35 pounds (16 kg). The maximum sizes can reach up to 100 pounds (45 kg); above this weight it becomes difficult to move the pieces, and it is preferred to ram the mud in situ, resulting in a different typology known as rammed earth. In dry climates, adobe structures are extremely durable, and account for some of the oldest existing buildings in the world. Adobe buildings offer significant advantages due to their greater thermal mass, but they are known to be particularly susceptible to earthquake damage if they are not somehow reinforced. Cases where adobe structures were widely damaged during earthquakes include the 1976 Guatemala earthquake, the 2003 Bam earthquake, and the 2010 Chile earthquake. Buildings made of sun-dried earth are common throughout the world (Middle East, Western Asia, North Africa, West Africa, South America, southwestern North America, Spain, and Eastern Europe.) Adobe had been in use by indigenous peoples of the Americas in the Southwestern United States, Mesoamerica, and the Andes for several thousand years. Puebloan peoples built their adobe structures with handsful or basketsful of adobe, until the Spanish introduced them to making bricks. Adobe bricks were used in Spain from the Late Bronze and Iron Ages (eighth century BCE onwards). Its wide use can be attributed to its simplicity of design and manufacture, and economics. A distinction is sometimes made between the smaller adobes, which are about the size of ordinary baked bricks, and the larger adobines, some of which may be one to two yards (1–2 m) long. The word adobe /əˈdoʊbiː/ has existed for around 4000 years with relatively little change in either pronunciation or meaning. The word can be traced from the Middle Egyptian (c. 2000 BC) word ɟbt 'mud brick'. Middle Egyptian evolved into Late Egyptian, Demotic or 'pre-Coptic', and finally to Coptic (c. 600 BC), where it appeared as τωωβε tōʾpə. This was adopted into Arabic as الطوب aṭ-ṭawbu or aṭ-ṭūbu, with the definite article al- attached. tuba, This was assimilated into the Old Spanish language as adobe , probably via Mozarabic. English borrowed the word from Spanish in the early 18th century, still referring to mudbrick construction. In more modern English usage, the term 'adobe' has come to include a style of architecture popular in the desert climates of North America, especially in New Mexico, regardless of the construction method. An adobe brick is a composite material made of earth mixed with water and an organic material such as straw or dung. The soil composition typically contains sand, silt and clay. Straw is useful in binding the brick together and allowing the brick to dry evenly, thereby preventing cracking due to uneven shrinkage rates through the brick. Dung offers the same advantage. The most desirable soil texture for producing the mud of adobe is 15% clay, 10–30% silt, and 55–75% fine sand. Another source quotes 15–25% clay and the remainder sand and coarser particles up to cobbles 50 to 250 mm (2 to 10 in), with no deleterious effect. Modern adobe is stabilized with either emulsified asphalt or Portland cement up to 10% by weight.