[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/all2en\/wiki14\/hochfester-beton-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/all2en\/wiki14\/hochfester-beton-wikipedia\/","headline":"Hochfester Beton \u2013 Wikipedia","name":"Hochfester Beton \u2013 Wikipedia","description":"When high -strength concrete are classified in the standards from a cylinder pressure strength from greater 50 N\/mm\u00b2 up to","datePublished":"2018-06-28","dateModified":"2018-06-28","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/all2en\/wiki14\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/all2en\/wiki14\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/44a4cee54c4c053e967fe3e7d054edd4?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/44a4cee54c4c053e967fe3e7d054edd4?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Enzyklop\u00e4die","logo":{"@type":"ImageObject","@id":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","url":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/d\/dd\/Abbinden-NSC.png\/310px-Abbinden-NSC.png","url":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/d\/dd\/Abbinden-NSC.png\/310px-Abbinden-NSC.png","height":"170","width":"310"},"url":"https:\/\/wiki.edu.vn\/all2en\/wiki14\/hochfester-beton-wikipedia\/","wordCount":1267,"articleBody":"When high -strength concrete are classified in the standards from a cylinder pressure strength from greater 50 N\/mm\u00b2 up to and including 100 N\/mm\u00b2 (C 100\/115). The first high -strength concrete standardized in the Eurocode 2 is a C55\/67 that has to achieve a characteristic cylinder pressure resistance of at least 55 N\/mm\u00b2. The high -strength concrete is characterized by a dense and homogeneous structure with a small proportion of capillary pore. In the concrete recipe, they differ primarily from the normal concrete by a lower water cement value. In normal-proof emphasis, the water addition is usually 0.5 to 0.7 times the cement mass. At high -strength emphasis, this relation is reduced to values \u200b\u200bbetween 0.35 and 0.25. Thus, high -resistant concrete contains less water than is necessary for the complete hydration of the cement (W\/Z ~ 0.40). In addition, there is only a little unbound water in the cement stone that causes the formation of capillary pores. In addition, unshydrated cement clinker is available as a high -resistant “surcharge” that has an optimal network of the surrounding hydrated cement stone.  Hydratation Normal party Betons From the point of view of construction site -friendly processing, low water cement values \u200b\u200bare only possible by using powerful assembly agents. The effect of the assembly agents is based on a distribution of the cement day glomerates and a kind of lubricating effect. Since the addition of microsilica stiffens the fresh concrete and creates a “sticky” consistency, the fluid consistency area (KF) or the spread class F4 must be striving for more than 49 cm.  Hydration of high -strength concrete with silica In addition to the low W\/Z value, the higher concrete strengths are achieved primarily by the addition of the finest additives. Silica dust is usually added to the production of high -strength emphasis. The silica items are around 30 to 100 times smaller than the cement grains and almost completely consist of amorphema silicon dioxide, which is created in the production of silica trees and ferrosilicium and is obtained from the flue gases using electrical filters.The strength -increasing effect of microst dust can be explained by three causes: Due to their shape and size, the silica paper is able to fill some of the pore space between the cement grains. The structure of the cement stone, which caused the flow agent due to the dispersing effect of the flow agents, is significantly increased and a higher density is achieved (microf\u00fcller effect). In addition to the cement hydration, a puzzle -based secondary reaction between the calcium hydroxide created during cement hydration runs C a ( O H )2{displaystyle Ca(OH)_{2}} and the silica dust S i O2{displaystyle SiO_{2}} away. Here is calcium silicathydrate C S H {displaystyle CSH} formed that has a higher strength compared to the starting materials. An important cause is also the significant improvement of the microstructure in the composite zone between the cement stone and the surcharge. The reason is a reduction in the calcium and etringite content in the contact zone. This can also be seen from high -strength concrete test bodies on the break surfaces. The surfaces are relatively smooth, the fracture is not carried out around the surcharges as with normal -proof concrete, but through the surcharges. The improved composite between the surcharge and the matrix mainly contributes to the increase in strength, the Puzzolan secondary reaction only around 20 percent. In high -strength emphasis, cements are also used, which are far more finely than on the usual 3200 to 3500 Blaine of the Portland cement PZ35 and can have values \u200b\u200baround 5,000 to 5500 Blaine. These fine -tunes are extremely complex to produce due to their large specific surface; They consume considerably more energy to grind and cannot be produced with any kind of cement mills. They also place special requirements for the separation procedure (separation) and the machines used for this. In addition, increased requirements are placed on storage in order to be able to maintain the high specific surface via the warehouse duration. As early as the early 1950s, Otto Graf managed to produce concrete with a compressive strength of 75 N\/mm\u00b2. With a f\/z value of 0.32, basalt surcharges as well as with low temperatures and under pressure, strengths up to 140 N\/mm\u00b2 were achieved in the mid-1960s by Kurt Walz in the laboratory. The breakthrough for the production of high -strength location concrete only brought the discovery of the silica as a concrete additive and the development of high -performance fleeing in the 1970s. The first application in Germany took place in 1990 with a B85 at the Trianon high -rise in Frankfurt. Further experiences are available in 2008 with regard to the use of high -strength concrete for bridge buildings and floor slabs according to the Water Household Act.  "},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/all2en\/wiki14\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/all2en\/wiki14\/hochfester-beton-wikipedia\/#breadcrumbitem","name":"Hochfester Beton \u2013 Wikipedia"}}]}]