Taipa (Building Material)

Rammed earth, also known as taipa in Portuguese, tapial in Spanish, pisé (de terre) in French, and hangtu (Chinese: ; pinyin: hāngtǔ), is a technique for constructing foundations, floors, and walls using natural raw materials such as earth, chalk, lime, or gravel. It is an ancient method that has been revived recently as a sustainable building material used in a technique of natural building.

Rammed earth is simple to manufacture, non-combustible, thermally massive, strong, and durable. However, structures such as walls can be laborious to construct of rammed earth without machinery, e. g., powered tampers, and they are susceptible to water damage if inadequately protected or maintained.

Edifices formed of rammed earth are on every continent except Antarctica, in a range of environments including temperate, wet, semiarid desert, montane, and tropical regions. The availability of suitable soil and a building design appropriate for local climatic conditions are the factors that favour its use.

Manufacturing rammed earth involves compressing a damp mixture of earth that has suitable proportions of sand, gravel, clay, and/or an added stabilizer into an externally supported frame or mould, forming either a solid wall or individual blocks. Historically, additives such as lime or animal blood were used to stabilize it, while modern construction adds lime, cement, or asphalt emulsions. To add variety, some modern builders also add coloured oxides or other materials, e.g. bottles, tires, or pieces of timber.

...
Wikipedia