Adobe

A mud brick ( adobe ) is a with your hands or with a casing shaped and air-dried cubes of clay, which is used in earth building. A variation is the air-dried brick made ​​of clay with fillers such as sand, straw or animal dung ( camel, cattle) with less weight and more favorable heat transfer coefficient. Also by the admixture of a greater stability is achieved during the drying process. In case of heavy rain, the mud brick softens again, mud-brick walls must be protected against wetness duration and driving rain. Blowing a mudbrick is depending on the appropriateness of the mix and burn method of brick, clay brick or clinker.

History of the mudbrick

The use of air- dried clay is an important since Neolithic culture of human technology. The methods of earth building have been developed depending on the available material mixture for the bricks and fuel for the kilns.

Archaeological finds are the so-called tells. The mud-brick architecture is believed to have been invented in several parts of the world independently ( Middle East, Central America, China). The corresponding construction is called earth building.

Adobe

Synonymous with unfired bricks often finds the coming of the Spanish name Adobe, which in turn " raging " over the Arab from Coptic = brick derives. Dissemination took this name with Spanish descriptions of the pre-Columbian buildings in Central and South America. The Pyramid of the Sun in Teotihuacán, the Huaca del Sol and Huaca Larga in Peru are considered the world's largest adobe structures.

Production

For the preparation of all air brick clay is used, which - depending on the culture and methods - a proportion of sand, vegetable fibers or other fillers are added. Various additives are among some of the types of production also mixed. What matters is the amount of award: too much sand, for example, reduces the carrying capacity of a brick, too much clay makes him cracked. The addition of dry or soaked straw - as in Egypt - must be sufficiently well so that the tile gets its right strength. On completion, carefully kneaded, viscous clay mixture is introduced into a rectangular wooden mold or in other special shapes, such as special vessels. Once the mass is consolidated, the frame or the special form be removed. With progressive drying in air, the product is - brick or commodity - usually stored in the shade because direct sunlight in bricks with a high clay content can cause by too rapid water evaporation cracks, what brick can be useless for heavy loading, and smaller items are fragile. In parts of Latin America as well as in Mesopotamia but also the blanks to direct sunlight as previously exposed to dry today.

Properties

Adobe are against water running and strong moisture sensitive (but not against increased humidity). But they offer in dry, hot climates such as in Egypt, Iran, Yemen, Bolivia, despite the lack of insulation decisive advantages over many other building materials, in particular the heat storage. During the day, the bricks heat up under the influence of sunlight and release the stored heat slowly at night to the environment. Thus, it remains cool during the day and warm at night in a built of mud brick buildings. Such buildings are provided on the sunny side with a thicker wall, as this more energy is saved. To enhance the effect will now additionally used in our latitudes, in some cases, glass or translucent ( transparent ) insulation to keep the heat in the component ( short-wave light radiation is transmitted, the long-wave heat radiation to the outside but reduced).

Reuse of original building material

Adobe can be completely recycled. Mortar and plaster residues can usually be very easily separated from the stones. All full and half stones can be used for walls again. Smaller chunks may be soaked with water ( slurried ) and processed to mortar, plaster or new earth blocks.

Mudstones

The mudstones defined until 1973, the pre-standard DIN 18951 as a generic term for Lehmquader, Lehmbatzen or green compacts. Lehmquader are made of earth-moist, lean ( silikatarmem ) clay. The clay is (according to DIN ) tamped into molds with dimensions of 365x230x110 mm ³ and then air dried. Due to their weight around 20 kilos they are hard to brick up. Lehmbatzen be made from a moist, medium fat clay mixture, the fibrous aggregates are attached. Here, a " chunk " of clay is thrown into the wooden form.

Green compacts are produced industrially from fat, which is " blue ", so strong clayey loam. As green compacts the still unfired clay blocks in brick plant are referred to as this as well as Earth blocks consist mainly of clay and sand.