Anchor rail

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Anchor rail with welded anchor and hammer head screw

An anchor rail is a profile steel that is installed or poured into concrete . It consists of a profile steel in a C-profile made of galvanized structural steel or stainless steel with rear anchors for anchoring in the concrete.

The system includes special screws. They are called hammer-head bolts or hook-head bolts because of their shape. The rail is set in concrete so that these special screws can be inserted into the slot in the profile. They can be moved along the rail and thus allow adjustments. One can at these anchor channels various structural parts such as ventilation ducts and pipes attach. The brand names Halfenenschiene , Jordahlschiene and MOSO-Ankerschiene have become generic names for anchor channels .

Types of anchor channels

Cold rolled anchor channel
Hot-rolled anchor channel

Any connecting structures can be attached to the cast-in rails. A distinction is made between hot-rolled and cold-profiled anchor channels. Hot-rolled profiles with a similar geometry have a higher permissible load. They are also better suited for attachments with dynamic loads, such as crane runway attachments or machine attachments.

A filling is placed in the slot of the rail ex works, which protects against the ingress of concrete during the concreting process. The filling is offered in two different versions: as a full foam filling that can be easily pulled out completely or as a styrofoam filling that can be partially removed quickly. For corrosion protection, the profiles are offered in stainless steel or galvanized qualities.

Anchor rails with serrations can also ensure the load bearing in the longitudinal direction of the rail by means of a form fit. The special profiles can also take up dynamic loads and, thanks to the three-dimensional load take-up, are also suitable for fastening guide rails in the elevator shaft, for example.

history

The concrete and reinforced concrete construction at the beginning of the 20th century required new ways of attaching various structures to the concrete surface. Trapezoidal wooden strips with angled nails were set in concrete for lighter loads. Later, cast-in steel girders with special claws for fastening were developed. This enabled higher loads to be introduced into the concrete. Another development were S-shaped steel rails into which hook bolts were hung. In 1913, Anders Jordahl developed a C-shaped rail with hook-head screws that was hung back by brackets, which was patented on December 11, 1913 under the number 292751. The term “anchor rails” has been used since 1925 and industrial production is carried out. In 1929, the Halfen rail was developed , which had a novel geometric design to prevent concrete spalling.

As of 1976, general building inspectorate approvals from the German Institute for Structural Engineering are required for anchor channels in Germany .

Regulations

In 2009 the new European standard CEN / TS 1992-4 was published. It regulates the procedure for "dimensioning the anchoring of fastenings in concrete".

The series of standards corresponds to the rules of technology and takes into account the latest research findings in the field of anchoring technology. In order that the calculation methods specified therein can be used, manufacturer and product-specific values ​​for the respective anchor channels, such as resistances or shape coefficients, are required. These key figures are in turn regulated in the European technical approval of the respective product.

Applications

Anchor rails are used, for example, to fasten precast concrete parts, supply lines, facing masonry, reinforced concrete facades, consoles and elevator guide rails, canopies or other structures. In plant engineering, anchor rails are installed for the adjustable fastening of various components. Curved rails are used in tubbing for fastening media or contact wire in tunnels. Depending on the manufacturer's range of products, suitable anchor channels can be used for a wide variety of constructions with different requirements in terms of load-bearing capacity, fire protection and corrosion protection. Materials with different corrosion protection requirements can also be combined.

literature

  • Rolf Kindmann, Michael Stracke: Connections in steel and composite construction. Ernst & Sohn Verlag, Berlin 2009, ISBN 978-3-433-02916-9 .
  • P. Gerlach (Eds.), M. Coenen, E. Lupberger, A. Schmidt, G. Unold, Fr. Wicke, C. Zietemann: Freytag's auxiliary book for mechanical engineering for mechanical engineers and for teaching at technical schools. Eighth edition, published by Julius Springer, Berlin 1930.

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