Concrete element comprising a sound-absorber

Abstract

The invention concerns a reinforced concrete element comprising an at least partially open-cell foamed, sound-absorbing material which is partially exposed on a surface of the concrete element. The surface on which the foamed material is exposed consists only partially of the foamed material and the reinforcement is partially surrounded by the foamed material. The invention further concerns a method of producing the concrete element and the use thereof as an acoustic ceiling in a building.

Claims

1. A reinforced concrete element comprising a sound-absorbing, at least partially open-cell foamed material, which is partially exposed on a surface of the concrete element, where the surface on which the foamed material is exposed consists only partially of the foamed material, wherein a reinforcement is partially enclosed by the foamed material.

2. The concrete element according to claim 1, wherein the concrete element is plate-shaped and is not completely permeated by the foamed material in an extension direction from the surface having the partially exposed foamed material to the opposing surface.

3. The concrete element according to claim 1, wherein the surface on which the foamed material is exposed consists of 10 to 40% by area of the foamed material.

4. The concrete element according to claim 1, wherein the foamed material is distributed at periodic intervals in the form of strips on the surface.

5. The concrete element according to claim 1, wherein the foamed material comprises a geopolymer foam.

6. The concrete element according to claim 1, wherein the foamed material has a density of 200 to 400 kg/m.sup.3.

7. The concrete element according to claim 1, wherein the foamed material comprises an epoxy resin.

8. The concrete element according to claim 1, wherein the foamed material consists of 20 to 90% by volume of air.

9. The concrete element according to claim 1, wherein the element is a ceiling, wall, or roof structure.

10. A method for producing the concrete element according to claim 1, wherein the reinforcement and the sound-absorbing foamed material are introduced in the form of a reactive free-flowing mass into a formwork and the reactive free-flowing mass is at least partially cured.

11. The method for producing a concrete element according to claim 10, wherein the reactive free-flowing mass comprises an alkali-activated aluminosilicate binder.

12. The method for producing a concrete element according to claim 10, wherein the reactive free-flowing mass comprises a surfactant and is foamed by mechanical introduction of air.

13. The method for producing a concrete element according to claim 10, wherein the reactive free-flowing mass comprises at least one water-emulsifiable epoxy compound and/or at least one self-emulsifying epoxy resin emulsion.

14. The method for producing a concrete element according to claim 10, wherein the reactive free-flowing mass comprises fibers.

15. A method comprising installing the concrete element according to claim 1 as an acoustic ceiling in a building.

Description

(1) In the drawings

(2) FIG. 1 shows a top view of a ceiling element according to the invention having periodically arranged absorber strips;

(3) FIG. 2 shows a schematic cross-section of a ceiling element according to the invention having periodically arranged absorber strips, wherein the reinforcement is aligned parallel to the surface of the concrete element;

(4) FIG. 3 shows a schematic cross-section of a ceiling element according to the invention having the periodically arranged absorber strips, wherein the reinforcement is a lattice support.

(5) The invention will be explained in greater detail hereafter with reference to the appended drawings.

EXAMPLES

Production of the Geopolymer Foam

(6) TABLE-US-00001 TABLE 1 Trade name (producer) mass [grams] % by weight Potassium Emsure (Merck 50.04 16.41 hydroxide 1 mol/L KGaA) Potassium water K45M (Simtek 87.50 28.69 glass Corporation) Surfactant Glucopon DK225 2.20 0.72 (BASF SE) Metakaolin Metamax (BASF 71.10 23.32 SE) Foam glass Fillite 106 (Omya 55.60 18.23 GmbH) Flue ash Lhnen (STEAG 15.50 5.08 Power Minerals GmbH) Dispersion powder Acronal S430 P 15.00 4.92 (BASF SE) PAN fibers 6.7 dtex/6 mm 8.00 2.62 (Trevira GmbH) Total mass 304.94 100.00

(7) The geopolymer foam is produced using a fully automatic foaming machine for continuous foaming of liquids and low viscosity pastes, which operates according to the stator-rotor principle (type Mgromix+ from Heitec Auerbach GmbH).

(8) The components listed in Table 1 are mixed except for the surfactant in a construction site mixer (Zwangsmischer XM from Collomix Rhr and Mischgerte GmbH). A suspension having a density of 1000-1200 g/L results. Finally, the surfactant is added and mixed for a further 30 seconds. The suspension is pumped via a hose into the fully automatic foaming machine.

(9) The processing parameters are as follows: mixing head speed 300 rpm system air pressure 2 bar material throughput 120 L per hour.

(10) The produced foam has a density of 375 g/L and has an air content of 55% by volume. The air content is determined in this case via the change of the volume in relation to the unfoamed suspension based on DIN EN 1015-6. The foam has a dry crude density of 274 kg/m.sup.3. The crude density of the produced foam is determined by the quotient of the mass thereof and the volume which the foam occupies.

Example 1

(11) The ceiling element according to the invention is 1 m1.5 m0.12 m in size. A reinforcing net B500A (according to DIN 488) having a mesh width of 100 mm100 mm, wherein the steel rods have a diameter of 6 mm, is firstly installed in a corresponding formwork. Subsequently, the geopolymer foam, which is obtained as described above, is sprayed onto the reinforcement in the form of strips and dried for 2 hours at 25 C. and 80% ambient humidity and subsequently concreted. For the production of the ceiling elements, an in-situ concrete of strength class C25/30 having a maximum grain size of 8 mm was selected. The fresh concrete has a density of 2328 kg/m.sup.3 and has a consistency class of F5.

(12) This ceiling element according to the invention is shown in FIG. 1. The ceiling element has a width of 100 cm (reference sign 8) and a length of 150 cm (reference sign 9). It has absorber strips made of geopolymer 3. The absorber strips made of geopolymer foam are arranged at a spacing of 25 cm (reference sign 10) on the surface. The absorber strips made of geopolymer foam have a width of 5 cm (reference sign 6). Furthermore, the surface is formed by strips made of concrete 1.

(13) FIG. 2 shows this ceiling element according to the invention in cross-section. The ceiling element has a structural height of 12 cm (reference sign 7) and has absorber strips made of geopolymer foam 3. The absorber strips made of geopolymer foam have a width of 5 cm (reference sign 6) and a structural height of 5 cm (reference sign 4) and are arranged at a spacing of 20 cm (reference sign 5). Furthermore, the ceiling element consists of concrete 1. The reinforcement 2 is a construction steel mat B500A (according to DIN 488) having a mesh width of 100 mm100 mm, wherein the steel rods have a diameter of 6 mm. The reinforcement is partially enclosed by the absorber strips made of geopolymer foam and is aligned parallel to the surface of the concrete element.

Example 2

(14) Example 2 differs from example 1 in that a grating support is used as the reinforcement.

(15) FIG. 3 shows this ceiling element according to the invention in cross-section. The ceiling element has a structural height of 12 cm (reference sign 7) and has absorber strips made of geopolymer foam 3. The absorber strips made of geopolymer foam have a width of 5 cm (reference sign 6) and a structural height of 5 cm (reference sign 4) and are arranged at a spacing of 20 cm (reference sign 5). Furthermore, the ceiling element consists of concrete 1. The reinforcement is a lattice support having the designation Filligran-E-Gittertrger from Filigran Trgersysteme GmbH & Co. The lattice support consists of rebar steel B500A (according to DIN 488), wherein the steel rods have a diameter of 6 mm. The reinforcement is partially enclosed by the absorber strips made of geopolymer foam.