Jump Main Menu. Go directly to the main content

Sección de idiomas

Fin de la sección de idiomas

Sección de utilidades

Fin de la sección de utilidades

You are in:

  1. Slipform

Portal / Slipform

Start of main content

The slipform is a construction technique used in concrete works with no cold joints, where the reinforcement, cast, concrete pouring and uncast are done all at the same time, unlike the traditional methods done by phases.

The method consists in the construction of a small formwork (1.00-1.20 m) that has the shape of the element to be built. This formwork has the exact geometry and it is stiff. It is assembled on the ground level, each face of the slipform joined to the other by two yoke legs and two yoke beams. This elements are light and can be separeted in small parts. The yoke beams are placed around 70 cm above the working platform, in order to allow the mounting of the horizontal rebars. This yoke beams are separated in between them around 1.5 m. In each yoke beam an hydraulic jack is installed. It moves upwards climbing a jack rod or tube. This rod transmits the loads to the foundatios.

The concrete is poured in the slipform and, as it hardens, the whole system is lifted every 4 to 8 min, in short stroke lengths (20-30 mm). The hydraulic jacks are designed to climb by small steps and have devices to guarentee the uniform and smooth lifting. All the jacks are connected to an hydraulic pump. This pump can be switched from manual operation to automatic operation at the chosen lifting speed.

The pouring of concrete, placing of reinforcement and assembly of small formwork for openings, is done progressively as the lifting process takes places. All this tasks are done from the working platform placed at the upper level of the slipform. There is a second platform under the working platform that is used to treat the concrete surface  that  comes out of the slipform.

The loads from the platforms and slipform is transmitted to the jack rods. This jack rods remain inside the concrete wall untill the end of the slide. They can be removed because they are protected against the fresh concrete by a tube that slipforms a hole along the wall.

The works are continuos in 24/h shafts although there can be planned stops in the slipform. Special  measures must be taken to aviod that concrete glues the slipform.

Ths slipform speed is determined by the following conditions:

a)Seting time of the concrete: Depends on the type of cement, temperature of the concrete, atmospheric temperature and humidity.

b) Auxiliary equipment:

  • Batchimg plant.
  • Crane, whinche, distributor arm, for lifting concrete and reinforcement.
  • Work-force for pouring the concrete, mounting of reinforcement, formwork for openings, plates.
  • Auxiliary equipment for curing the concrete.
  • Access to platforms.

End of main content