Socket joint
Socket joints are mechanical connections for reinforcing bars and are used in reinforced concrete construction in special cases to connect reinforcing bars to one another. As a rule, an overlap joint is used to connect two bars , in which the ends of the bars are placed parallel to one another over a certain length. Mechanical connections are only used when such an overlap joint is not (meaningfully) possible, e.g. B. with a very tight reinforcement layer, with very long required overlap lengths or when connecting rods protruding far from a component would disrupt the construction process.
Socket joints are designed in such a way that the connection can absorb and transmit all forces that occur in the reinforcing steel. The connections are calculated and made in accordance with the applicable standards for reinforced concrete construction (formerly e.g. DIN 1045-1, today EC 2-1-1 ). In Germany, mechanical fasteners require a general building inspectorate approval or a European technical approval .
Screw connection
A screw connection consists of a screw socket , a pipe with an internally cut thread into which the reinforcing bars to be connected can be screwed. The sleeve can be pressed onto one of the rods in the factory, it then only needs a thread for the rod to be supplemented. Sockets with two threads are screwed onto both rods to be connected. The reinforcing bars must first be cut with the appropriate threads in the manufacturer's works.
Because of this special processing of the bars and the manufacture of the sleeves, a screw connection costs significantly more than an overlap joint. Depending on the diameter and type of socket, a joint (one socket and cutting two threads) costs between 15 and 120 euros, whereas in the case of an overlapping joint, only the additional steel in the joint area causes costs that are no more than a few euros.
Shear bolt sleeves
Another type of mechanical connection uses sleeves with shear bolts. The bars to be connected do not have to be prepared separately for this connection. The sleeve does not contain any thread, but is slightly larger in diameter than the associated rods and serrated on the inside. After plugging in, several shear bolts are screwed through the socket and thus clamp the reinforcing bar in the socket.
Since the bars do not have to be prepared in the factory, the use of shear bolt sleeves is advisable if, for example, a change in the reinforcement is necessary during the construction process.
Individual evidence
- ↑ a b c Konrad Zilch, Gerhard Zehetmaier: Dimensioning in structural concrete construction: According to DIN 1045-1 (version 2008) and EN 1992-1-1 (Eurocode 2) . Springer, ISBN 978-3-642-01029-3 , pp. 558 f .