DE29903114U1 - Punching shear reinforcement - Google Patents

Description

Company Syspro-Group Concrete Components e.V., Karlsruher Str. 32, 68766 Hockenheim

"Punch shear reinforcement"
5

The innovation relates to a punch shear reinforcement for strengthening flat ceilings and/or foundation slabs according to the generic term of the main claim.

For ceiling panels that are connected to columns, a

important load case from the so-called punching of the supports through the mostly thin plates. Numerous measures have been developed to improve the plate area around the supports, all of which are based on steel construction components in the form of strips, dowels and crosses.

These built-in components are always made specifically to the dimensions of the application and must be ordered from the construction site or concrete plant with sufficient lead time. This can easily lead to difficulties in production due to delays.

The installation of these components is complicated and time-consuming and the steel components are also complex to manufacture.

When installed in so-called prefabricated panels with lattice girders,

protect the protruding steel components during storage and transport.

The innovation is based on the task of creating a ceiling component that uses only the usual main ceiling building materials, such as concrete and reinforcement mesh, in the complex ceiling area and is optimized in such a way that the effect of the previously known steel components is achieved and preferably exceeded in terms of punching shear, but the connections to the supports and normal ceiling areas are simplified.

This problem underlying the innovation is solved by the teaching of the main claim.

Advantageous embodiments are explained in the subclaims.

In other words, a special, refined precast concrete component is created, which, according to another key feature of the innovation, can be additionally equipped with cross bolts that are inserted at an angle

and are firmly connected to the upper chord or the lower chord.

The concrete component according to the innovation is usually a rectangular or square element, preferably with floor plan dimensions of 1 m to 2.50 m, which is designed in a stepped manner in the direction of the ceiling thickness in the edge area. In the outer edge area, the concrete component can have a thickness of 3 to 6 cm, with protruding lattice girders creating and facilitating the connection to the adjacent ceiling concrete of the normal area. In the area adjacent to the support, the thickness is around 5 - 9 cm less than the final ceiling thickness, whereby upper reinforcement can later be inserted on site in the space created in this way.

In the case of high loads from the support(s), the element can be connected directly to the rising support by forming a cap, and an opening can be provided in the area of the support for further connection.

In addition, a recess can be provided for installation in the concrete component. If the concrete components are large, the lattice girder top flanges can take on the function of the reinforcement to be installed on site. This

enables an economical execution, since after the

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element a smaller amount of reinforcement is required and the effect of reinforcement staggering is created.

The ceiling concrete itself can be a high-strength mixture to which fibers can also be added.

The lattice girders are preferably spaced 10 - 20 cm apart and are provided with the cross bolts provided for in the area immediately around the support to be connected. The cross bolts are preferably installed at an angle of

Installed at an angle of 25 to 38° from the vertical.

The principle of the bolts and the fiber concrete ensures that the inclined position of the cross bolts ensures optimal anchoring of the cross bolts in the cracked concrete.

because more concrete is activated to prevent the anchorage from breaking. By combining it with fibers, the cracks are reduced and an anchoring base without any prior damage is provided.

Due to the variable angle of the cross bolts, one bolt version is sufficient for ceiling thicknesses between 18-40 cm.

The cross bolts can be designed as double-headed bolts, in which case it is only necessary that the bolts are connected to the grid

carriers are tied together.

When welding the bolt to the upper flange of the lattice girder, a lower base plate on the cross bolt is sufficient, whereby this base plate can be welded on in the factory.

An example of the innovation is explained below using the drawing. The drawing shows

Fig. 1 is a sectional view of an innovative

Concrete component and in

·

Fig. 2 the use of the new cross bolts

for clarity in two ceiling thicknesses.

In Fig. 1, a precast concrete part 1 is shown, which consists of concrete, where the underside 8 can be seen. Furthermore, 2 denotes a lattice girder, which has an upper chord 3 and a lower chord 4. Below the lower chord 4, reinforcement bars 5 can be seen embedded in the concrete, which run transversely to the lower chord 4. The precast concrete part 1 is designed in a stepped manner, so that a middle area is created, which is about 5 to 9 cm

below the upper edge of the ceiling to be constructed later.

In the edge area of the precast concrete element, this is designed in steps, so that the upper chord 3 and an area of the lattice girder 2 are exposed and can be connected to the ceiling later.

component can be connected in the simplest way.

At a distance from the center of the precast concrete element, cross bolts 6 are inserted, which can be designed as head bolts, with the upper head preferably being firmly connected to the upper flange 3.

the, e.g. bolted or welded, while the lower end can have a base plate 7, which may end freely in the concrete, but can also be firmly connected to the lower flange 4. The cross bolt 6 has an inclination α relative to the vertical, whereby this inclination can vary between 20 - 40°

This makes it possible, as shown schematically in Fig. 2, to use a cross bolt 6 of a certain length in conjunction with precast concrete components of different thicknesses, since the height of the concrete component can be compensated for simply by varying the angle α.

The innovative design of the prefabricated component 1 means that the complex and complicated area of a prefabricated ceiling is completely relocated to the factory and only simpler work is required on the construction site, such as

Transport, handling and connection.

The strength of the slab is increased in the right places and the economic effect of the concrete on compression is fully exploited.

Series production is no longer disrupted and one cross bolt length is sufficient for several ceiling thicknesses.

Claims (10)

HABBEL &igr; HABBEL PATENT ATTORNEYS PO Box 3429 ♦ 48019 Münster h ^: .-q! habbel DIPL.-INQ. LUTZ HABBEL EUROPEAN PATENT ATTORNEYS DIPL.-QEOQR. PETER HABBEL TELEPHONE (0251) 535 780 ♦ FAX (0251) 531 996 OUR FILE: (please specify} S252/21 555 X/SC Münster, 19 February 1999 Company Syspro-Group Concrete Components e. V., Karlsruher Str. 32, 68766 Hockenheim "Punch shear reinforcement" Protection claims: 1. Punching shear reinforcement for strengthening flat ceilings and foundation slabs, characterized by a rectangular or square concrete component (1), the edge areas of which are graded in height with lattice girders (2) distributed over the entire surface with upper chord (3) and lower chord (4) and reinforcing bars (5) provided below the lower chord. 2. Punching shear reinforcement according to claim 1, characterized by transverse bolts (6) reinforcing the lattice girders (2). 3. Punching shear reinforcement according to claim 1 or 2, characterized by an inclination of the transverse bolts (6) of 20 - 40° from the vertical. 4. Punching shear reinforcement according to claim 3, characterized by an inclination of the transverse bolts (6) of 25 - 38° relative to the vertical. 5. Punching shear reinforcement according to claim 2, characterized in that the transverse bolts (6) are designed as double-headed bolts. 6. Punching shear reinforcement according to claim 5, characterized in that the transverse bolts (6) are firmly connected, ie welded or bolted, to the upper flange (3) and/or the lower flange (4) of the lattice girder (2). 7. Punching shear reinforcement according to one of the preceding claims, characterized in that the concrete of the concrete component (1) is made of high-strength concrete. 8. Punching shear reinforcement according to claim 7, characterized characterized in that the concrete of the concrete component (1) is made of fiber concrete. 9. Punching shear reinforcement according to one of the preceding claims, characterized in that the distance between the The distance between the lattice girders (2) is approximately 20 cm. 10. Punching shear reinforcement according to one of the preceding claims, characterized in that a recess is provided in the concrete component (1) for later assembly in front of is seen.