clinker
Clinkers are bricks that are burned at such high temperatures that the pores of the material to be burned are closed when the sintering process begins . Clinker hardly absorbs water and is very resistant. The name can etymologically be traced back to the fact that when hard-fired bricks / clinker are knocked together, a high sound is produced. In the past, clinkers were also known as hard-fired bricks .
Basics
Clinkers consist of chamottes , feldspars and white or red-burning clay minerals . Various color nuances can be achieved by adding various additives to the raw material . For the production of bricks, the raw materials clay and water are mixed and shaped industrially using an extrusion process. Hand-formed clinker bricks are used for special applications, for example in the restoration of listed buildings. During the subsequent drying process, the water content is reduced to around 3%, with “good clinker” it should be below 2%. After that, clinker is burned at 1100 to 1300 ° C in a tunnel kiln (previously in a ring kiln ), in contrast to 800 to 1000 ° C for normal bricks.
In Germany, clinker bricks are standardized according to DIN 105 . A distinction is made between solid clinker (KMz) with a density of 2.0 kg / dm³ to 2.2 kg / dm³ and vertical hole clinker (KHLz) with a density of 1.6 kg / dm³ to 1.8 kg / dm³. Because of the low proportion of air voids, all clinker bricks have relatively poor thermal insulation properties . Sewer clinkers are standardized according to DIN 4051 "Sewer clinker". Clinkers are frost-resistant and are therefore particularly suitable for facades . The formats of the clinker bricks are standardized according to DIN 1053 “ Masonry ”. The base for the different formats is the normal format (NF) with length 240 mm, width 115 mm and height 71 mm (other dimensions see brick ). For facade design, architects have bricks made with special dimensions and shapes.
When used for facades, a variety of form elements can be walled up (e.g. brick expressionism , see picture). In the past, clinkers were often used in civil engineering , for example in bridge construction , in the construction of sewers and water structures, in brick sluices or shafts or as paving clinker in road construction .
The sculptor Ernst Barlach worked with clinker bricks made according to his design.
The architects Fritz Schumacher and Fritz Höger promoted the modern brick building method in northern Germany.
sorts
Peat fire clinker
The clinker gets a special color, especially green tones, when it is burned with peat . Famous buildings with peat fire clinker are the Chilehaus and the Broschek-Haus in Hamburg. The last still operated ring kiln for peat fire clinker is in Nenndorf near Aurich . The clinker is marketed under the name Torfbrand Architektur Ringofenklinker from Nenndorf / Ostfriesland.
Greppin clinker
A hard-fired yellow brick is referred to as Greppin clinker , which - compared to normal brick - has a closed surface when the clinker is fired. Such clinker bricks were mostly used at the end of the 19th century for facing railway structures, e.g. B. Hannover Hauptbahnhof used.
Munsterland coal fire
The Münsterländer coal fire is characterized by classic clinker tones with distinctive coal fire bulges or light, sooty smoke plumes on the burning skin. Regionally mined clay from the Münsterland and Ruhr area coal is used for production. The combustion process prevailed with the beginning of industrialization . The Münsterland coal fire shaped the facades of numerous industrial buildings from the turn of the 19th and 20th centuries. One example is the Zollern colliery in Dortmund. The former prince-bishop's residence "Schloss Münster" and the former State Archives Münster, now the Westphalia department of the North Rhine-Westphalia State Archives , are faced with clinker bricks made from the characteristic coal fire.
literature
- Clinker (1), the . In: Adelung, Grammatical-Critical Dictionary of High German Dialect. Volume 2. Leipzig 1796, p. 1632.
- Clinker . In: Pierer's Universal Lexicon. Volume 9. Altenburg 1860, p. 582.
- Clinker . In: Otto Lueger: Lexicon of the entire technology and its auxiliary sciences. Vol. 5. Stuttgart, Leipzig 1907. p. 512.
- Paving clinker . In: Otto Lueger: Lexicon of the entire technology and its auxiliary sciences. Vol. 7. Stuttgart, Leipzig 1909. p. 99.
- Clinker streets . In: Otto Lueger: Lexicon of the entire technology and its auxiliary sciences. Vol. 5. Stuttgart, Leipzig 1907. pp. 512-513.
Web links
- Private page with material information and pictures