Exposed concrete, also called raw concrete or, by the French term, béton brut (French pronunciation: ), is an expression used to designate concrete that is left unfinished after setting, showing the patterns and marks printed on it by the formwork.[1] béton brut is not a material in itself, but rather an architectural expression of concrete.
History
The pioneers in the use of béton brut were modern architects such as Auguste Perret or Le Corbusier. Le Corbusier coined the term béton brut during the construction of the Unité d'Habitation in Marseille, France, completed in 1952.[2] The term began to spread widely when British architecture critic Reyner Banham associated it with brutalism in his 1966 book The New Brutalism: Ethic or Aesthetic? ("The New Brutalism: Ethic or Aesthetic?"), in which he described a group of new architectural designs, particularly in Europe.[3].
Beton brut became popular among modern architects, leading to the rise of the brutalist style, which peaked between the 1950s and 1970s. Brutalism has its basis in the philosophy of modern architecture, which promotes the honesty of materials, which is achieved through their raw expression. The essence of this philosophy lies in the imperfections of béton brut, which derives from the idea of creating an aesthetic based on the exposure of the components of a building, including the structure, the enclosure and the mechanical systems.[4] The result is the visibility of the marks and construction methods of the formwork used to cast the concrete. This form of concrete is also part of structural expressionism, which emerged as steel structures became more advanced and cost-effective.
Manufacturing
After setting, concrete usually receives a finishing treatment that smoothes its surface, eliminating any imperfections. In the case of béton brut, however, the concrete is left unfinished, thus preserving the pattern left by the formwork. The formwork is the structure into which fresh concrete is poured so that it sets and acquires the desired shape.[5] The aesthetics of concrete surfaces can be modified using different coatings of the formwork; For example, board formwork, smooth formwork, lining, formwork with molds, rolls with filters, etc. The type of material used to create the formwork (e.g. glass, wood, steel, etc.) also has an effect on the final result. When Le Corbusier coined the term, he was specifically referring to the plank-marked concrete he used to construct many of his post-World War II buildings.[3].
Exposed Concrete Structures
Introduction
Exposed concrete, also called raw concrete or, by the French term, béton brut (French pronunciation: ), is an expression used to designate concrete that is left unfinished after setting, showing the patterns and marks printed on it by the formwork.[1] béton brut is not a material in itself, but rather an architectural expression of concrete.
History
The pioneers in the use of béton brut were modern architects such as Auguste Perret or Le Corbusier. Le Corbusier coined the term béton brut during the construction of the Unité d'Habitation in Marseille, France, completed in 1952.[2] The term began to spread widely when British architecture critic Reyner Banham associated it with brutalism in his 1966 book The New Brutalism: Ethic or Aesthetic? ("The New Brutalism: Ethic or Aesthetic?"), in which he described a group of new architectural designs, particularly in Europe.[3].
Beton brut became popular among modern architects, leading to the rise of the brutalist style, which peaked between the 1950s and 1970s. Brutalism has its basis in the philosophy of modern architecture, which promotes the honesty of materials, which is achieved through their raw expression. The essence of this philosophy lies in the imperfections of béton brut, which derives from the idea of creating an aesthetic based on the exposure of the components of a building, including the structure, the enclosure and the mechanical systems.[4] The result is the visibility of the marks and construction methods of the formwork used to cast the concrete. This form of concrete is also part of structural expressionism, which emerged as steel structures became more advanced and cost-effective.
Manufacturing
After setting, concrete usually receives a finishing treatment that smoothes its surface, eliminating any imperfections. In the case of , however, the concrete is left unfinished, thus preserving the pattern left by the formwork. The formwork is the structure into which fresh concrete is poured so that it sets and acquires the desired shape.[5] The aesthetics of concrete surfaces can be modified using different coatings of the formwork; For example, board formwork, smooth formwork, lining, formwork with molds, rolls with filters, etc. The type of material used to create the formwork (e.g. glass, wood, steel, etc.) also has an effect on the final result. When Le Corbusier coined the term, he was specifically referring to the plank-marked concrete he used to construct many of his post-World War II buildings.[3].
When wooden boards are used to construct the formwork, the concrete takes on its texture as it sets, resulting in a final texture in the concrete that resembles wood. It is important to use the same type of wood throughout the job, especially in large buildings where the planks may be used multiple times, as the wood absorbs moisture, which can affect the final color of the concrete.[6] Other patterns can be created using textured metal formwork, or by hammering the result.[7] Wood-textured concrete is still popular in landscaping, especially in some Western European countries.
Surface processing techniques can also be used to create the béton brut aesthetic, such as in the case of washed concrete surfaces, photoconcrete or acidified surfaces. Specifically, high-quality reinforced concrete, achieved by leaving enough space between the formwork and the reinforcing bars for the concrete to flow freely, is called Sichtbeton in German and exposed cement in Italian, terms that can be translated as "exposed concrete."
[2] ↑ «Le béton brut». Le Corbusier - Ouvre complète (en francés). De Gruyter. 1995. pp. 180-189. ISBN 9783035602951. doi:10.1515/9783035602951.180.: https://dx.doi.org/10.1515%2F9783035602951.180
When wooden boards are used to construct the formwork, the concrete takes on its texture as it sets, resulting in a final texture in the concrete that resembles wood. It is important to use the same type of wood throughout the job, especially in large buildings where the planks may be used multiple times, as the wood absorbs moisture, which can affect the final color of the concrete.[6] Other patterns can be created using textured metal formwork, or by hammering the result.[7] Wood-textured concrete is still popular in landscaping, especially in some Western European countries.
Surface processing techniques can also be used to create the béton brut aesthetic, such as in the case of washed concrete surfaces, photoconcrete or acidified surfaces. Specifically, high-quality reinforced concrete, achieved by leaving enough space between the formwork and the reinforcing bars for the concrete to flow freely, is called Sichtbeton in German and exposed cement in Italian, terms that can be translated as "exposed concrete."
[2] ↑ «Le béton brut». Le Corbusier - Ouvre complète (en francés). De Gruyter. 1995. pp. 180-189. ISBN 9783035602951. doi:10.1515/9783035602951.180.: https://dx.doi.org/10.1515%2F9783035602951.180