In the production of round concrete parts (e.g. sewer pipe systems), steel reinforcements are placed into the mould. Concrete is known to be very pressure resistant but in no way tensile or bending resistant. Depending on the installation position different areas of tension arise, which have to be supported differently by steel reinforcements. The best reinforcement cage, by theory, would start with a round shape to support the area of pipe, which is connected with the next pipe, go on with an oval geometry for the middle of the pipe and end with a round shape again, for the second connection end.

So far it hasn’t been possible to produce reinforcement cages with a changed geometrical shape (e.g. round-oval-round) economically. In this case the producer of concrete parts always used two round cages with a different diameter to reduce the tensile strength of a special area of the pipe with the first cage and with the second one they wanted to cover the usually 90 degrees shifted tension of another area. Of course, this results in unequally higher costs and masses for the respective products. This not only has an influence on the component times and component costs, but also manifests itself significantly in the further handling effort.

With our new cage welding machine it is possible to produce cages with variable, intermeshing geometry.In the production process, the reinforcing cages are flowed from one shape to another one and back to the first again, for example round-oval-round. Thus, the tensile stresses, which are located in the concrete pipe by 90 ° in different diameter ranges, will be covered by only one reinforcement cage.
This is achieved by the new development of a spreading system, in which the linear movement of a main spreading drive is divided into different linear movements of the individual sliders, each holding a longitudinal. A particular challenge now lies in the hydraulic control of two, partly in synchronism, partly in the controlled counter-direction hydraulic drives.

Oval reinforcements are already known and are state of the art, of course, but pipes which include oval reinforcements as main part have no support in the connection areas of the pipes (spigot and bell).
These connection areas have to be round on tightness reasons and therefore round reinforcements at the end of the pipes are essential for a robust and fatigue endurable and tight concrete pipe.

There is no machine known worldwide, which is able to produce reinforced cages with variable geometry economically at this time. A patent for the revolutionary system, we developed is pending and published in Germany and at international level.

Right at the beginning of development, machines of this type were at the centre of customer interest, which steadily increased with their rising popularity and the possibility of reporting not just theoretical but also real benefits.
Many customers are currently taking advantage of the opportunity to look at these machines in their area and get an idea of ​​the quality of the reinforcements and the potential savings in their production.

Added value of the pipe product

  • Industrial manufactured R-O-R cage
  • Continuous reinforcement from spigot to bell
  • High welding quality by optimized product tolerances
  • Individual adjustment of the cage on to the respective pipe product
  • Less production weight
  • Cost reduction of the concrete pipe, because of less reinforcement costs
  • Less handling costs
  • Increasing of the production rate
  • Better concrete filling of the pipe

Added value in the cage production

  • Time savings by reducing the number of reinforcement cages (50%)
  • Time savings due to the no longer necessary assembly of the double cage
  • Material savings, since only one cage is used (about 45%)
  • Saving of wear parts, since only one cage has to be produced
  • Reduction of the effort in cage handling

 Added value for the environment

  • Conservation of steel resources as only one basket is produced (45%)
  • Saving energy, as less steel and less energy is needed for welding
  • Possible reduction of traffic, as possibly more pipes at a transport can be loaded