DE102024111006A1 - Hollow ceiling slab and method for its production - Google Patents

Abstract

Hollow core slab (1) comprising an upper slab (10) and a lower slab (20) connected to the upper slab (10). According to the invention, the upper slab (10) comprises projecting reinforcement elements (4) embedded in a matrix material of the upper slab (10), and reinforced webs (6), wherein the reinforcement elements (4) and the webs (6) are integrally connected to the matrix material of the lower slab (20). The cross-section of at least some of the webs (6) widens in the direction of the lower slab (20). The web (6) and the lower slab (20) form a connecting penetration region (22).
Method for producing a hollow core slab having an upper slab and a lower slab connected to the upper slab, comprising the steps of: inserting reinforcement elements into a mold for the upper slab; introducing and compacting the matrix material of the upper slab into the mold for the upper slab; placing a lost web mold for a web onto the matrix material of the upper slab; introducing and compacting the matrix material of the web; roughening the surface of the web; curing and demolding the upper slab; introducing and compacting the matrix material of the lower slab in the mold for the lower slab; rotating the upper slab so that the projecting reinforcement elements and the web point downwards towards that of the mold for the lower slab; inserting the reinforcement elements and the web into the fresh concrete of the lower slab; curing and demolding the lower slab.

Description

The invention relates to a hollow-core slab and a method for producing a hollow-core slab, also known as a concrete double-core slab. Double-walled concrete components, such as wall elements in particular, but also hollow-core slabs, are known from the prior art. In wall elements, the space between them is first concreted in-situ, on the construction site, to reduce transport costs. However, slab elements with a favorable ratio between load-bearing capacity on the one hand and weight and material usage on the other are already being used.

The printed matter CN 102535710 A describes a ceiling beam that is open at the top on one side and intended for concreting. According to the publication DD 151 424 A1 In-situ concreting is planned, with a lightweight slab serving as the support.

In contrast, ceiling elements are also known that do not require concreting and in which a hollow space remains inside. From the publication WO 2021/043428 A1 Fiber-reinforced concrete elements, in particular slabs and webs, are known which are joined, in particular glued, to form a ceiling. WO 2024/002854 A1 Textile-reinforced concrete strips connect an upper and a lower slab of the ceiling. In the printed publication DE 10 2013 106 174 A1 The cavity, on the other hand, is formed by a cellulose honeycomb core.

The printed matter US 3 475 529 A describes a ceiling element, a hollow core slab, which is assembled from two parts, one of which is prestressed. First, a part with continuous ribs 3 is manufactured and inserted with these ribs into a freshly concreted, flat concrete slab traversed by tendons. To create a connection between the first element with ribs and the flat, prestressed element, in some embodiments, wires are inserted in the area of the ribs (cf. 8 ) or by different types of concrete (cf. 9 ) achieves an improved connection to the second element. However, due to demoldability, the rib is narrowest where it connects to the second part, a particularly critical connection point that must absorb shear forces under load.

It is therefore an object of the invention to offer a hollow ceiling slab in which the connection between the two parts is particularly stable and has a defined force-transmitting design, but which does not require concreting on site.

The problem is solved by a hollow core slab having an upper slab and a lower slab connected to the upper slab. According to the invention, the upper slab has projecting reinforcement elements and reinforced webs embedded in a matrix material of the upper slab. The reinforcement elements and the webs have two sides, a first and a second side, which are arranged opposite one another along the longitudinal axes and parallel to the longitudinal extent. The reinforcement elements and the webs are embedded in the upper slab with a first side. The reinforcement elements and the webs are embedded in the matrix material of the lower slab with a second side. The cross-section of at least some of the webs widens towards the lower slab so that improved anchoring with the lower slab and force introduction into the lower slab can occur. The web and lower slab form a connecting penetration area. Preferably, concrete is provided as the matrix material and the hollow core slab is designed as a concrete double slab.

The reinforcement elements preferably comprise lattice girders that connect the upper and lower slabs and, in particular, absorb tensile loads. Additional reinforcement elements, such as longitudinal chords, can also be used.

It has proven advantageous if at least some of the webs are flanked, at least on the flanks, by a lost web form, whereby the webs particularly absorb compressive loads. The web form preferably consists of a layer of expanded metal formed into a V-shaped cross-section with a flattened bottom.

A preferred embodiment of the hollow core slab has a height of 250 mm, with at least some of the webs comprising three 19 mm lattice girders, two of which flank the web in the normal position, and the central lattice girder mounted overhead and embedded in the matrix material of the web. The upper plate of this embodiment is 70 mm thick, and the lower plate is 60 mm thick. The web penetrates 10 mm into the matrix material of the lower plate, forming a penetration zone there.

1. 1. Einlegen von Bewehrungselementen mit einer ersten Seite in eine vorzugsweise oben offene Form für die Oberplatte, wobei dies Bewehrungsmatten, Gitterträger in Normallage und Stegform mit eingesetztem, umgekehrtem Gitterträger umfasst, wobei die Stegform vorzugsweise aus Streckmetall besteht;
2. 2. Einbringen des Matrixmaterials, insbesondere Beton, und Verdichten, z. B. durch Rütteln der Form, der Oberplatte in die Form für die Oberplatte;
3. 3. Einbringen und Verdichten des Matrixmaterials, insbesondere Beton, des Stegs;
4. 4. Aufrauen der Oberfläche des Stegs;
5. 5. Aushärten und Entformen der Oberplatte;
6. 6. Einbringen und Verdichten des Matrixmaterials der Unterplatte in der Form für die Unterplatte;
7. 7. Drehen der Oberplatte, sodass die abragenden Bewehrungselemente und der Steg nach unten zu der der Form für die Unterplatte weisen;
8. 8. Einsetzen der Oberplatte mit einem Teil der Bewehrungselemente und des Stegs, jeweils mit deren zweiter Seite, in den frischen Beton der Unterplatte;
9. 9. Aushärten und Entformen der Unterplatte.

The object is also achieved by a method for producing a hollow ceiling slab having a top plate and a bottom plate connected to the top plate, characterized by the following steps:

1. 1. Inserting reinforcement elements with a first side into a mold for the top plate, which is preferably open at the top, this comprising reinforcement mats, lattice girders in the normal position and web form with inserted, inverted lattice girder, wherein the web form is preferably made of expanded metal;
2. 2. Introducing the matrix material, in particular concrete, and compacting it, e.g. by vibrating the mold, of the upper plate into the mold for the upper plate;
3. 3. Placing and compacting the matrix material, in particular concrete, of the web;
4. 4. Roughening the surface of the bridge;
5. 5. Curing and demolding of the top plate;
6. 6. Inserting and compacting the matrix material of the sub-plate in the mold for the sub-plate;
7. 7. Rotate the top plate so that the projecting reinforcement elements and the web point downwards towards the form for the bottom plate;
8. 8. Inserting the upper slab with part of the reinforcement elements and the web, each with their second side, into the fresh concrete of the lower slab;
9. 9. Curing and demolding of the base plate.

Lattice girders are preferably used as reinforcement elements. A lattice girder consists of a plurality of parallel bars that are placed diagonally one above the other and connected to each other at the intersection points to form a lattice. The upper and lower edges of the girder are generally formed by continuous chords. It is further preferred that concrete be used as the matrix material, and that the upper and lower slabs be cast in concrete. Thus, the hollow core slab according to the invention is designed as a concrete double slab.

According to an advantageous embodiment of the method, the central lattice girder is held overhead with short 6-iron bars under the longitudinal chords.

• 1: schematisch eine geschnittene Seitenansicht einer Oberplatte einer Ausführungsform einer erfindungsgemäßen Betondoppeldecke;
• 2: schematisch eine geschnittene Seitenansicht einer Oberplatte mit Unterplatte einer Ausführungsform einer erfindungsgemäßen Betondoppeldecke vor den Zusammenfügen; und
• 3: schematisch eine geschnittene Seitenansicht einer erfindungsgemäßen Betondoppeldecke.

The invention is explained in more detail below based on the description of exemplary embodiments and their illustration in the accompanying drawings. They show:

• 1 : schematically a sectional side view of a top plate of an embodiment of a concrete double ceiling according to the invention;
• 2 : schematically a sectional side view of an upper plate with a lower plate of an embodiment of a concrete double floor according to the invention before joining; and
• 3 : schematically a sectional side view of a concrete double ceiling according to the invention.

1 : schematically shows a sectional side view of an upper slab 10 of an embodiment of a concrete double slab 1 according to the invention. The upper slab 10 was taken from a mold (not shown here), into which the matrix material concrete and, prior to concreting, the reinforcement elements, the lattice girders 4 and the reinforcement mats 5, were inserted. In addition, the web form 8, together with the lattice girder 4 mounted in an inverted position, was placed on the reinforcement mat 5, which was also inserted into the mold, prior to concreting. The web form 8, with its V-shaped cross-section, consists of a formed expanded metal, which is shown in the sectional view by dashed lines. To form the web 6, the web form 8 was also filled with the matrix material concrete fresh-on-fresh almost up to the upper edge after the upper slab 10 had been concreted. The surface is roughened to facilitate the later connection with the matrix material of the lower slab 20 (cf. 2 and 3 ) to improve.

2 shows a schematic sectional side view of an upper slab 10 with a lower slab 20 of an embodiment of a concrete double slab 1 according to the invention before assembly. For this purpose, the upper slab 10 was turned over so that the webs 6 and the lattice girders 4 point downwards toward the freshly concreted lower slab 20. Subsequently, the upper slab 10 is lowered so far that the lattice girders 4 and the ribs 6 penetrate the fresh concrete of the lower slab 20 and bond with it as it hardens.

3 shows schematically a sectional side view of a concrete double ceiling 1 according to the invention, after the upper slab with the webs 6 and the lattice girders 4 has been sunk into the fresh concrete of the lower slab 20 to such an extent that a penetration area 22 is created for the webs 6.

In the illustrated embodiment of the concrete double slab 1 according to the invention, the total height is 25 cm, with the upper slab being 70 mm thick and the lower slab 60 mm thick. The gap is bridged by the lattice girders 4 and the ribs 6 and does not need to be filled with concrete, resulting in savings in material and weight.

List of reference symbols

1

Hollow ceiling slab, concrete double ceiling

4

Reinforcement elements, lattice girders

5

Reinforcement elements, reinforcement mat

6

web

8

Bridge shape

10

Top plate

20

Base plate

22

Penetration area

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• CN 102535710 A [0002]
• DD 151 424 A1 [0002]
• WO 2021/043428 A1 [0003]
• WO 2024/002854 A1 [0003]
• DE 10 2013 106 174 A1 [0003]
• US 3 475 529 A [0004]

Claims (10)

Hollow ceiling slab (1) having a top slab (10) and a bottom slab (20) connected to the top slab (10), characterized in that the top slab (10) has projecting reinforcement elements (4, 5) and reinforced webs (6) embedded with a first side in a matrix material of the top slab (10), wherein the reinforcement elements (4, 5) and the webs (6) are embedded with a second side in the matrix material of the bottom slab (20), wherein the cross section of at least some of the webs (6) widens in the direction of the bottom slab (20), and wherein the web (6) and bottom slab (20) form a connecting penetration region (22). Hollow ceiling slab according to Claim 1 , where the matrix material is concrete. Hollow ceiling slab according to Claim 1 or 2 , wherein the reinforcement elements (4) comprise lattice girders connecting the upper plate (10) and lower plate (20). Hollow ceiling slab according to one of the preceding claims, wherein at least some of the webs (6) are flanked at least on the flanks by a lost web form (8). Hollow ceiling slab according to Claim 4 , wherein the web shape (8) consists of a layer of expanded metal which is formed into a V-shaped cross-section with a flattened bottom. Hollow ceiling slab according to one of the preceding claims, wherein the hollow ceiling slab (1) has a height of 250 mm, wherein at least some of the webs (6) comprise three 19 mm lattice girders, two of which flank the web (6) in the normal position and the central lattice girder is mounted overhead and embedded in the web (6), and wherein the upper plate is 70 mm and the lower plate is 60 mm thick, and wherein the web penetrates 10 mm into the matrix material of the lower plate and forms a penetration region. Method for producing a hollow core slab (1) which has an upper slab (10) and a lower slab (20) connected to the upper slab (10), characterized by the steps of: • inserting reinforcement elements (4, 5) and a lost web form (8) for a web (6) into a mold for the upper slab (10); • introducing and compacting the matrix material of the upper slab (10) into the mold for the upper slab (10); • introducing and compacting the matrix material of the web; • roughening the surface of the web; • curing and demolding the upper slab; • introducing and compacting the matrix material of the lower slab in the mold for the lower slab; • rotating the upper slab so that the projecting reinforcement elements and the web point downwards towards that of the mold for the lower slab; • inserting the reinforcement elements and the web into the fresh concrete of the lower slab; • curing and demolding the lower slab. Procedure according to Claim 7 , with lattice girders being used as reinforcement elements. Procedure according to Claim 7 or 8 , where concrete is used as the matrix material and the top and bottom slabs are concreted. Method according to one of the Claims 7 until 9 , whereby the central lattice girder is held overhead with short 6 iron bars under the longitudinal chords.