CS210002B1 - Method of making the cavities in the concrete segments and device for executing the same - Google Patents

Description

The invention solves a method of forming cavities in concrete parts by means of a drawn vibrating core.

Prefabricated concrete bridge or other. structures are most often made up of beams of different shapes. The statically advantageous cell cross-section encounters a problem during production. Therefore, for production reasons, the so-called open section beams without cavities are preferred, even at the expense of higher mass consumption.

The cavity formation is quite well solvable for beam lengths up to approx. 20 m, where several cores have been proven to be pulled out after concreting. The problem is complicated in the manufacture of beams of longer lengths or on long tracks, although a number of different methods are known here, most often as a formwork of various materials.

It is known that hardened cardboard reinforced with wooden spacers is used to form cavities in bridge prefabricates. The disadvantage is the untreatable warping of the formwork thus formed during concreting, so that the goemetric cross-sectional shape cannot be guaranteed.

Also used as permanent shuttering are polystyrene blocks, which are usually laid on the concrete layer and require a firm protection against flooding by the buoyancy of the concrete mixture. Polystyrene as a diesel product is relatively expensive and requires large storage space,

In some cases, pipes of different cross-section are used as permanent shuttering and require various anchors against flooding, such as thin-walled pipes, coiled-metal pipes, asbestos-cement pipes, PVC and others.

Wooden shuttering for large consumption of timber and human work is practically out of the question.

Also, cavities are formed on long tracks with stretched patent wires at a spacing of approx. 5 cm, with strutted wooden frames. Tensioned wires along the perimeter of the cavity are wrapped with steel and then with paper or PVC foil, which must transfer the pressure of the concrete mixture. After concreting and partial hardening, the wires are loosened, pulled out and can be used for further production. The disadvantage is high labor intensity.

There is known a method of forming cylindrical cavities by the Spiroll system, where the rotating screws with the transition to the cylinder are supported on the treated concrete mixture. By the resulting reaction, the entire concrete unit is moved forward. This very productive method can only be used for parts without transverse reinforcement.

Creating a closed cross-section is sometimes also solved by so-called two-stage production.

In the first phase, the trough-shaped beam is concreted and flat or eventually slabs are used as lost formwork of the ceiling. differently shaped from different materials / wood, hardboard, asbestos-cement, um. mass, sheet metal etc.), and then the upper part of the beam is concreted. It is also possible to use shuttering which, when the concrete has hardened, is pulled out or pulled out of the beam. Two-phase concreting prolongs the technological cycle and increases labor intensity.

These drawbacks are overcome by the method of forming cavities of arbitrary length according to the invention, which is based on a steel vibrating core which is continuously or intermittently shunted by 210002 while filling the mold with a concrete mixture. With some delay behind the concreting face, given the speed of displacement and the length of the core, the core leaves a cavity formed behind it.

The steel core guided inside the cross-section is ideally positioned for the perfect processing of the concrete mixture with which it is in direct contact. The kinetic energy of the front vibrating part of the core is transferred with minimal loss to the mixture, which is intensively compacted.

The steel vibrating core has at least two parts: vibrating and damping. Indeed, once the concrete mixture is compacted, further vibration is undesirable as it could disrupt the side walls and ceiling of the cavity. To prevent this, a damping part or possibly another run-out part is connected downstream of the vibration part, the purpose of which is to safely retain the shape of the cavity.

Maintaining the ceiling is effectively aided by its geometric shape in the form of a vault and by a suitably chosen composition and consistency of the concrete mixture. The advantage of this method is that no auxiliary or built-in formwork is eliminated, thus saving material and labor costs, parts / beams / can be concreted in one shot, which

Claims (2)

A method of forming cavities in concrete parts, characterized in that the cavity is formed by a steel vibrating core located within the cross-section of the part as it is advanced over progressing concreting and 2a at the same time compacting the concrete mixture. shortens the technological cycle and reduces labor, by placing the source of vibration inside the cavity, the concrete mixture is compacted with high effect, which reduces energy demand, significantly extends the life of the mold, which does not suffer from vibration and . 1 to 3 schematically illustrates the process of forming a cavity with a steel vibrating core. The concrete mixture 1 is poured into the mold 2 and compacted by the vibrating part 2 of the core, in which the source of vibration 4 is placed. The vibrating plate 8 is progressively assisted by the shifting of the core. After displacement of the core, a cavity / chamber / beam 9 is formed with a separate top plate 2 '. The present invention can be used in particular in the manufacture of concrete cell beams or slabs, especially over longer lengths or on long tracks where the continuous process is best applied. OF THE INVENTION Device for carrying out the method according to claim 1, characterized in that the steel vibrating core is formed from at least two parts, a vibrating (3) and a damping (5).