RU131029U1 - ELEMENT OF MONOLITHIC CONCRETE COVERING - Google Patents

Abstract

A monolithic concrete slab element containing a base in the form of a thin-walled profile of a C-shaped cross section with an reinforcing cage installed in it and at least two flat elements installed across the base, fastened to the base, provided with slots made with the possibility of fixing reinforcement passing through them.

Description

The utility model relates to the field of construction and can be used in the construction of prefabricated-monolithic, mainly often-ribbed ceilings.

The basis of fixed formwork for often ribbed concrete floors are beams, which are load-bearing elements that perceive the pressure of the concrete mixture. Beams, as a rule, are a monolithic (concrete, metal, composite, etc.) base with a reinforcing cage installed in it, consisting, most often, of longitudinal and transverse, including diagonal reinforcement, fastened together with a wire and welding. The manufacture of beams with a monolithic base is carried out, most often, in the factory. The manufacture of hollow base beams can be carried out both in the factory and directly at the construction site.

However, when concrete is poured with a fixed formwork assembled using beams with a monolithic concrete base, the so-called “cold seam” appears, violating the monolithic integrity of the cross section of the concrete core and leading to a decrease in its strength, especially at the junction of the “old” concrete of the beam and the “new »Concrete poured into fixed formwork. In addition, beams with a monolithic concrete base have a sufficiently large weight, which limits their use in projects related to transportation, movement at a construction site, lifting to the upper floors of buildings under construction and reconstruction.

Using beams with a hollow base completely solves the problem of a cold seam. However, this necessitates reliable fixation of the reinforcing cage in the hollow base, since during concreting, the unsecured reinforcing cage can be displaced in any direction. To ensure the necessary (design) strength of the finished floor, to increase its fire resistance, the following condition must be fulfilled: a sufficient protective layer of concrete is provided around the reinforcement of the frame during concreting. The location of the reinforcing cage necessary to create a protective layer in the hollow base of the beam can be achieved constructively through the use of fixing elements.

A technical solution is known, set forth in application No. 201121850 (dated July 19, 2012) for the utility model “Element of monolithic concrete flooring” (decision on delivery dated September 27, 2012), according to which fixing elements are used to fasten the reinforcing cage, which are a steel strip bent to form at least two lodgements and supports in contact with the inner and / or outer surfaces of the base. The fixing element is installed in the hollow base of the beam, the reinforcing cage is laid and secured to it in any suitable way.

However, in the manufacture of floors with high load-bearing capacity, a situation may arise when, when concrete is filled with beams under the influence of hydrostatic pressure of a liquid concrete mixture, the C-shaped thin-walled profile can be deformed, which leads to an increase in concrete consumption, a change in the geometric dimensions of the permanent formwork and even its possible destruction in concreting process. A curved steel strip installed inside the thin-walled profile cannot prevent deformation (disclosure) of the thin-walled profile. When mounted on the outer surface of the base, the curved steel strip slightly inhibits the change in the shape of the thin-walled profile, but cannot completely eliminate this undesirable phenomenon with increased loads due to insufficient rigidity of the curved strip in the direction of possible profile opening. In some cases, the geometric dimensions of the thin-walled element do not allow the possibility of installing a curved strip inside the profile.

The technical result of the claimed utility model is to increase the strength of the fixed formwork element of the often ribbed precast monolithic overlap.

This technical result is achieved due to the fact that in the element of a monolithic concrete floor containing a base in the form of a thin-walled profile of a C-shaped cross section with a reinforcing cage installed in it, at least two flat elements are fixed across the base, fastened to the base, provided slots made with the possibility of fixing the reinforcement passing through them.

Flat elements mounted across the base and bonded to it ensure that the shape of the profile is maintained. Slots made in flat elements allow you to fix the diagonal or transverse reinforcement of the frame passing through them. Such a bonded integral design of fixed formwork provides uniform (design, regulatory, defined by building codes) beam filling with concrete. The design has sufficient rigidity and provides high strength overlap.

The essence of the claimed technical solution is illustrated by the following drawings:

Figure 1 is an isometric image of the claimed element with installed fixing flat elements;

Figure 2 is an enlarged image of a fragment of a beam with a fixing element;

Figure 3 - image of a flat locking element;

Figure 4 - image of a flat locking element with flanging;

5 is an image of a flat locking element with vertical stops;

6 is an image of a fragment of the finished floor using the claimed element.

7 is an image of a fragment of the formwork using fixing elements with vertical stops.

The claimed element of a monolithic concrete floor (beam) contains a base 1 made of a thin-walled metal profile with a C-shaped cross-section, as well as a reinforcing cage 2. The fixing 3 element is fixed across the base 1. The fixing 3 element is provided with slots 4, the dimensions of which can be placed in the transverse (diagonal) reinforcement of the frame 2. The fastening of the fixing 3 elements with the base 1 is usually carried out with self-tapping screws 5, rivets or welding. The fastening of the fixing 3 elements with the reinforcing cage 2 is carried out in any available way, for example, using a knitting wire, welding, crimping, etc.

In addition to the slots 4 for fixing the reinforcement in the fixing 3 elements, holes 6 can be made, which allow using the knitting wire to attach additional longitudinal frame reinforcement to it. The flat fixing 3 element can be made with a flange, which allows to prevent the "opening" of the C-shaped profile without the use of screws, rivets or welding. On the fixing 3 element can be made one or more vertical stops 7, allowing you to lock in a given position elements located between adjacent beams.

For the manufacture of a C-shaped profile, various profiling machines are used. The locking elements are usually made by stamping on hydraulic or mechanical presses. The beam is assembled both in the factory and at the construction site. To do this, a reinforcing cage 2 is inserted into the C-shaped base 1 of a given length. Fixing 3 elements are installed across the base at a distance of 1.5-2 meters from each other, which are fastened to the base with self-tapping screws 5, rivets or welding.

The fixing 3 elements can have a different configuration, depending on the features of the ceiling structure. It can be made in the form of a plate with slots and the holes provided for in it for mounting on the base. In some cases, it is sufficient to use a narrower plate with slots made on one side. Also possible configurations of the locking elements may be the configuration shown in figure 4 and figure 5. The plates may be made of either metal or plastic or any other suitable material.

The transverse reinforcement of the carcass 2 is passed through the slots 4 on the fixing 3 elements, after which the frame is fastened to the fixing 3 elements using a knitting wire, welding, or any other suitable method. Thus obtained products fulfill the role of beams in the ceiling, which, in accordance with the project, are mounted on walls and temporary supports. Between the beams are laid blocks of floors or other elements provided by the project. The assembled structure is a fixed formwork, which allows to obtain a often-ribbed slab after concreting. Concrete poured into fixed formwork is compacted by any generally accessible method. After the concrete has set the strength specified by the design, the floor can be operated.

Claims (1)

A monolithic concrete floor element containing a base in the form of a thin-walled profile of a C-shaped cross-section with an reinforcing cage installed in it and at least two flat elements installed across the base, fastened to the base, provided with slots made with the possibility of fixing reinforcement passing through them.

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