DE102010011713B4 - Self-compacting concrete, process for its production and its use - Google Patents

Abstract

Self-compacting concrete, with a proportion of at least 340 kg blast furnace cement per m3 concrete, with the blast furnace cement having a proportion of 20% to 34% by mass of Portland cement clinker and a proportion of 66% to 80% by mass of blast furnace slag, with one proportion of at least 300 kg limestone powder per m3 of concrete, with a proportion of at least 1400 kg aggregate of sand, gravel or chippings per m3 of concrete, the aggregate having a maximum grain of 8 mm, with a styrene-acrylate copolymer with a proportion of 5 Mass% to 15 mass% of the mass of the blast furnace cement, with a high-performance superplasticizer based on polycarboxylate ether with a maximum proportion of 2 mass% of the mass of the blast furnace cement and with a water / cement ratio of maximum 0.5.

Description

The invention relates to a self-compacting concrete according to the features of the preamble of claim 1, a method for its production according to the features of the preamble of claim 3 and its use according to the features of the preamble of claim 5.

From the state of the art it is known to apply a mortar-based layer in plaster on surfaces to be repaired or repaired or to repair such surfaces with a shotcrete layer.

A disadvantage of the previous solutions is that in the renovation / repair of listed concrete surfaces / facades often required original structures can not be produced. The surface does not correspond to a switched concrete surface. In addition, restricted accessibility often prevents professional renovation.

From the DE 10 2007 063 455 A1 are a concrete and a concrete railway sleepers known. The easily compressible or self-compacting concrete has proportions of cement and water, wherein the cement content is more than 400 kg / m ³ and in the processing state, the ratio of the mass fraction of water to cement content is less than 0.4.

From the DE 10 2008 037 171 A1 also concrete and a railway sleepers are known in concrete, wherein the easily compactable or self-compacting concrete shares of cement and water and wherein the cement content is more than 400 kg / m ³ and in the processing state, the ratio of the mass of water content to cement content less than 0 , 4 is. In addition to a proportion of a fine aggregate with grain sizes of up to 4 mm, the concrete also has a proportion of coarse aggregate with grain sizes between 8 mm and 16 mm, which consists at least partially of concrete recyclate. In addition, the concrete contains a plasticizer.

The invention is based on the object to provide an improved self-compacting concrete, which is particularly suitable for creating thin concrete layers, and further to provide a method for its preparation and its use.

The object is achieved by a self-compacting concrete with the features of claim 1, a method for producing a self-compacting concrete with the features of claim 3 and a use of self-compacting concrete with the features of claim 5.

Advantageous embodiments of the invention are the subject of the dependent claims.

According to the invention, a self-compacting concrete has a proportion of at least 340 kg blast-furnace cement per m ^{3 of} concrete, the blast-furnace cement having a proportion of 20% by mass to 34% by mass Portland cement clinker and a proportion of 66% by mass to 80% by mass blastfurnace slag. The blast furnace cement has a compressive strength of at least 32.5 N / mm ² and a maximum of 52.5 N / mm ² after 28 days.

Furthermore, according to the invention, the self-compacting concrete has a proportion of at least 300 kg of limestone powder per m ^{3 of} concrete.

Furthermore, the self-compacting concrete according to the invention has a proportion of at least 1400 kg of aggregate of sand, gravel or grit per m ^{3 of} concrete, wherein the aggregate has a maximum grain size of 8 mm maximum. A maximum grain size of 8 mm means that a maximum diameter of the stones or grains of the aggregate is 8 mm maximum. The aggregate is preferably porphyry gravel, which has a low elastic modulus.

The self-compacting concrete also contains a styrene-acrylate copolymer according to the invention with a proportion of 5% by mass to 15% by mass, preferably 5% by mass, of the mass of the blastfurnace cement. Such a copolymer is, for example, a dispersion and has a solids content of about 50% by mass. This self-compacting concrete is polymer modified by this styrene-acrylate copolymer.

Furthermore, according to the invention, the self-compacting concrete has a high-performance flow agent based on polycarboxylate ether with a proportion of not more than 2% by mass of the mass of the blastfurnace cement, preferably approximately 4 kg per m ^{3 of} concrete. If necessary, an exact dosage of the high-performance flow agent must be adapted in each case by tests in order to ensure optimum flowability of the self-compacting concrete.

The self-compacting concrete also has, according to the invention, a water / cement ratio of not more than 0.5.

The values of the above-mentioned formulation of the self-compacting concrete refer to the concrete during mixing or immediately after mixing and before applying the self-compacting concrete to a surface to be coated. After application to the surface to be coated cures and dries the concrete, so that in particular the water-cement ratio changes.

This polymer-modified self-compacting concrete is particularly suitable for creating thin concrete layers in the context of renovation and repair tasks, especially on vertical surfaces. By means of this polymer-modified self-compacting concrete, shuttering structures similar to an original surface can also be designed visibly on redeveloped surfaces. A concrete layer of this polymer-modified self-compacting concrete is also usable as a concrete repair layer having a final surface.

By means of the polymer-modified self-compacting concrete is an actual load-bearing concrete structure on which it is applied, estimated and it is a faithful geschalte concrete surface produced.

Due to its rheological properties, the polymer-modified self-compacting concrete applied to a surface to be repaired leveled automatically and vented, so that no additional compaction energy had to be applied.

By the polymer modification, a better stability of the formulation of the self-compacting concrete is achieved and adhesion of the self-compacting concrete to the surface to be repaired is significantly improved compared to materials according to the prior art.

Due to its composition, the polymer-modified self-compacting concrete also has a very high fatigue strength, as a result of which a future refurbishment effort of a surface renovated with the polymer-modified self-compacting concrete is significantly reduced and a much longer period of time until a renewed necessary refurbishment can be achieved.

In an advantageous embodiment, the polymer-modified self-compacting concrete has color pigments. In this way, a respective desired color of the polymer-modified self-compacting concrete can be produced. Due to a very light concrete base color due to the blast furnace cement, the polymer-modified self-compacting concrete has a very good colorability with color pigments, so that the polymer-modified self-compacting concrete is very well adapted to the respective color requirements.

In a method for producing a self-compacting concrete, according to the invention, a proportion of at least 340 kg of blast-furnace cement per m ^{3 of} concrete, the blast-furnace cement having a proportion of 20% by mass to 34% by mass of Portland cement clinker and a proportion of 66% by mass to 80% by mass. % Of blastfurnace slag, a proportion of at least 300 kg of limestone powder per m ^{3 of} concrete, a minimum of 1400 kg of aggregate of sand, gravel or grit per m ^{3 of} concrete, the aggregate having a maximum grain size not exceeding 8 mm, a styrene-acrylate Copolymer having a proportion of 5% by mass to 15% by mass, preferably 5% by mass, of the mass of the blastfurnace cement, a high-performance flow agent based on polycarboxylate ether with a proportion of not more than 2% by mass of the mass of the blastfurnace cement, preferably about 4 kg per m ^{3 of} concrete, and water mixed in a water / cement ratio of not more than 0.5.

The blast furnace cement has a compressive strength of at least 32.5 N / mm ² and a maximum of 52.5 N / mm ² after 28 days.

The aggregate is preferably porphyry gravel, which has a low elastic modulus. A maximum grain size of 8 mm means that a maximum diameter of the stones or grains of the aggregate is 8 mm maximum.

The styrene-acrylate copolymer is, for example, a dispersion and has a solids content of about 50% by mass. This self-compacting concrete is polymer modified by this styrene-acrylate copolymer.

If necessary, an exact dosage of the high-performance flow agent must be adapted in each case by tests in order to ensure optimum flowability of the self-compacting concrete.

This polymer-modified self-compacting concrete, which is preferably mixed in a compulsory mixer, is particularly suitable for creating thin concrete layers in the context of renovation and repair tasks, in particular on vertical surfaces. By means of this polymer-modified self-compacting concrete formwork structures similar to an original surface can also be made visible on redeveloped surfaces. A concrete layer of this polymer-modified self-compacting concrete may also be used as a concrete repair layer with a final surface.

By means of the mixed polymer-modified self-compacting concrete, an actual load-bearing concrete structure, to which it is applied after mixing, can be protected and a faithfully cast concrete surface can be produced.

Due to its rheological properties, the polymer-modified self-compacting concrete applied to a surface to be repaired leveled automatically and vented, so that no additional compaction energy had to be applied.

By the polymer modification, a better stability of the formulation of the self-compacting concrete is achieved and adhesion of the self-compacting concrete to the surface to be repaired is significantly improved over prior art materials.

Due to its composition, the polymer-modified self-compacting concrete also has a very high fatigue strength, as a result of which a future refurbishment effort of a surface renovated with the polymer-modified self-compacting concrete is significantly reduced and a much longer period of time until a renewed necessary refurbishment can be achieved.

In an advantageous embodiment, color pigments are added and mixed. In this way, a respective desired color of the polymer-modified self-compacting concrete can be produced. Due to a very light concrete base color due to the blast furnace cement, the polymer-modified self-compacting concrete on a very good colorability with color pigments, so that the polymer-modified self-compacting concrete can be very well adapted to color requirements of each.

In a use according to the invention of the self-compacting concrete for producing a concrete layer is a self-compacting concrete with a share of at least 340 kg blast furnace cement per m ³ concrete, the blast furnace cement from 20% to 34% by mass Portland cement clinker and a share of 66 mass having% to 80% by mass of blast furnace slag, in a proportion of at least 300 kg limestone dust per m ³ of concrete, with a proportion of at least 1,400 kg of rock grains of sand, gravel or crushed material per m ³ of concrete, the aggregate a maximum grain size of a maximum of 8 - mm, with a styrene-acrylate copolymer having a proportion of 5% by mass to 15% by mass, preferably 5% by mass, of the mass of the blastfurnace cement, with a high-performance flow agent based on polycarboxylate ether with a proportion of not more than 2% by mass. % of the mass of the blastfurnace cement, preferably about 4 kg per m ^{3 of} concrete, and with a maximum water / cement ratio of 0.5 to an area to be coated surface of a component.

The blast furnace cement has a compressive strength of at least 32.5 N / mm ² and a maximum of 52.5 N / mm ² after 28 days.

The aggregate is preferably porphyry gravel, which has a low elastic modulus. A maximum grain size of 8 mm means that a maximum diameter of the stones or grains of the aggregate is 8 mm maximum.

The styrene-acrylate copolymer is, for example, a dispersion and has a solids content of about 50% by mass. This self-compacting concrete is polymer modified by this styrene-acrylate copolymer.

If necessary, an exact dosage of the high-performance flow agent must be adapted in each case by tests in order to ensure optimum flowability of the self-compacting concrete.

This polymer-modified self-compacting concrete is particularly suitable for creating thin concrete layers in the context of renovation and repair tasks, especially on vertical surfaces. The concrete layer of this polymer-modified self-compacting concrete may also be used as a concrete repair layer with a final surface.

By means of the mixed polymer-modified self-compacting concrete, an actual load-bearing concrete structure, to which it is applied after mixing, can be protected and a faithfully cast concrete surface can be produced.

By the polymer modification, a better stability of the formulation of the self-compacting concrete is achieved and adhesion of the self-compacting concrete to the surface to be repaired is significantly improved over prior art materials.

Due to its composition, the polymer-modified self-compacting concrete also has a very high fatigue strength, as a result of which a future refurbishment effort of a surface renovated with the polymer-modified self-compacting concrete is significantly reduced and a much longer period of time until a renewed necessary refurbishment can be achieved.

In an advantageous embodiment, the polymer-modified self-compacting concrete has color pigments. In this way, a respective desired color of the polymer-modified self-compacting concrete can be produced. Due to a very light concrete base color due to the blast furnace cement, the polymer-modified self-compacting concrete has a very good colorability with color pigments, so that the polymer-modified self-compacting concrete can be very well color matched to specific requirements.

Conveniently, a formwork is arranged at a predetermined distance from the surface to be coated of the component and the polymer-modified self-compacting concrete is applied by filling in a cavity between the formwork and the surface to be coated of the component on the surface to be coated of the component. The formwork is preferably arranged at a predetermined distance of at least 2.5 cm to the surface of the component to be coated and has a smooth surface or, in a particularly advantageous embodiment, a structured surface.

A formwork material depends on a respective desired surface structure of the concrete surface of the polymer-modified self-compacting concrete and is for example plastic, metal or more preferably wood, as in this way also a grain of the wood on the concrete surface of the polymer-modified self-compacting concrete, d. H. can be made visible on the renovated surface as a relief in the polymer-modified self-compacting concrete. As a result, by means of the polymer-modified self-compacting concrete formwork structures similar to an original surface can also be made visible on redeveloped surfaces.

If the polymer-modified self-compacting concrete is filled between the formwork and the surface to be coated, it automatically levels out due to its rheological properties and vented, so that no additional compaction energy is required. The distance between the formwork and the surface to be coated may be constant over a longitudinal extent and / or over a transverse extent of the surface to be coated, or different distances may occur. However, a minimum distance of 2.5 cm must be maintained everywhere.

The polymer-modified self-compacting concrete is particularly advantageously used on a surface to be coated of the component, which is oriented substantially vertically. However, it can also be used on differently oriented surfaces, for example on horizontally oriented surfaces.

Embodiments of the invention are explained in more detail below with reference to drawings.

Show:

1 a schematic sectional view of a surface to be coated of a component, a formwork and a concrete layer of a polymer-modified self-compacting concrete, and

2 a schematic representation of a concrete surface coated with a polymer-modified self-compacting concrete surface.

Corresponding parts are provided in all figures with the same reference numerals.

1 shows a schematic sectional view of a surface to be coated 1 a component 2 , a formwork 3 and a concrete layer 4 from a polymer-modified self-compacting concrete. The component 2 is for example a vertical house wall to be rehabilitated, on which the thin concrete layer 4 is to be applied.

For the preparation of the polymer-modified self-compacting concrete a proportion of at least 340 kg of blast furnace cement per m ^{3 of} concrete, wherein the blast furnace cement has a content of 20% by mass to 34% by mass Portland cement clinker and a share of 66% by mass to 80% by mass blastfurnace slag , a proportion of at least 300 kg limestone dust per m ³ of concrete, a portion of at least 1,400 kg of rock grains of sand, gravel or crushed material per m ³ of concrete, the aggregate having a maximum particle size of at most 8 mm, a styrene-acrylate copolymer having a Proportion of 5% by mass to 15% by mass, preferably 5% by mass, of the mass of the blastfurnace cement, a high-performance flow agent based on polycarboxylate ether with a proportion of not more than 2% by mass of the mass of the blastfurnace cement, preferably about 4 kg per m ³ Concrete, and water in a water / cement ratio of not more than 0.5, more preferably mixed in a compulsory mixer or in exceptional cases, for example, in a free fall mixer ,

The blast furnace cement has a compressive strength of at least 32.5 N / mm ² and a maximum of 52.5 N / mm ² after 28 days.

The aggregate is preferably porphyry gravel, which has a low elastic modulus. A maximum grain size of 8 mm means that a maximum diameter of the stones or grains of the aggregate is 8 mm maximum.

The styrene-acrylate copolymer is, for example, a dispersion and has a solids content of about 50% by mass. This self-compacting concrete is polymer modified by this styrene-acrylate copolymer.

If necessary, an exact dosage of the high-performance flow agent must be adapted in each case by tests in order to ensure optimum flowability of the self-compacting concrete.

By the polymer modification, a better stability of the formulation of the self-compacting concrete is achieved and adhesion of the self-compacting concrete to the surface to be coated 1 is significantly improved over prior art materials.

Due to its composition, the polymer-modified self-compacting concrete also has a very high fatigue strength, as a result of which a future refurbishment effort of a surface renovated with the polymer-modified self-compacting concrete is significantly reduced and a much longer period of time until a renewed necessary refurbishment can be achieved.

In addition, color pigments can be added to the polymer-modified self-compacting concrete in order to produce a respectively desired color of the polymer-modified self-compacting concrete or of the surface to be coated 1 of the component 2 applied concrete layer 4 to reach. Due to a very light concrete base color due to the blast furnace cement, the polymer-modified self-compacting concrete on a very good colorability with color pigments, so that the polymer-modified self-compacting concrete can be very well color matched to specific requirements.

To the polymer-modified self-compacting concrete on the surface to be coated 1 of the component 2 apply the formwork 3 at a predetermined distance of at least 2.5 cm to the surface to be coated 1 of the component 2 arranged. The distance between the formwork 3 and the area to be coated 1 can be over a longitudinal extent and / or over a transverse extent of the surface to be coated 1 be consistent or different distances may occur. However, a minimum distance of 2.5 cm must be maintained everywhere.

The formwork 3 is for example made of plastic, metal or wood and has in the example shown here a structured surface 5 on. In a formwork 3 Wood, for example, already has a grain of wood as a structured surface 5 usable. In this way, the grain of the wood on a concrete surface 6 the concrete layer 4 made of polymer-modified self-compacting concrete, ie on the rehabilitated surface as a surface structure 7 be made visible in the polymer-modified self-compacting concrete, as in 2 shown in more detail. As a result, by means of the polymer-modified self-compacting concrete formwork structures similar to an original surface can also be made visible on redeveloped surfaces.

The polymer-modified self-compacting concrete is made by filling in a cavity between the formwork 3 and the area to be coated 1 of the component 2 on the surface to be coated 1 applied. Due to its rheological properties, it leveled automatically and vented, so that no additional compaction energy is required.

The polymer-modified self-compacting concrete is, as shown here, particularly advantageous on a surface to be coated 1 of the component 2 can be used, which is oriented substantially vertically. However, it can also be used on differently oriented surfaces, for example on horizontally oriented surfaces.

In 2 is the concrete surface 6 the surface coated with polymer-modified self-compacting concrete 1 schematically illustrated and has a structured surface 5 the formwork 3 corresponding surface structure 7 as a relief.

LIST OF REFERENCE NUMBERS

1

to be coated surface

2

component

3

formwork

4

concrete layer

5

structured surface

6

concrete surface

7

surface structure

Claims (9)

Self-compacting concrete, containing at least 340 kg of blast-furnace cement per m ^{3 of} concrete, the blast-furnace cement having a proportion of 20% by mass to 34% by mass of Portland cement clinker and a proportion of 66% by mass to 80% by mass blastfurnace slag Share of at least 300 kg of limestone powder per m ^{3 of} concrete, with a minimum of 1400 kg of aggregate of sand, gravel or grit per m ^{3 of} concrete, the aggregate having a maximum grain size of not more than 8 mm, with a styrene-acrylate copolymer containing one Proportion of 5% by mass to 15% by mass of the mass of the blastfurnace cement, with a high-performance flow agent based on polycarboxylate ether with a maximum proportion of 2% by mass of the mass of the blastfurnace cement and with a maximum water / cement ratio of 0.5. Self-compacting concrete according to claim 1, characterized by color pigments. A method for producing a self-compacting concrete, characterized in that a proportion of at least 340 kg of blast furnace cement per m ^{3 of} concrete, wherein the blast furnace cement content of 20 mass% to 34 mass% Portland cement clinker and a proportion of 66 mass% to 80 mass -% of blastfurnace slag, containing at least 300 kg of limestone powder per m ^{3 of} concrete, a minimum of 1400 kg of aggregate of sand, gravel or grit per m ^{3 of} concrete, the aggregate having a maximum grain size of 8 mm, a styrene acrylate -Copolymer with a proportion of 5% by mass to 15% by mass of the mass of blast furnace cement, a high performance flow agent based on polycarboxylate with a maximum of 2% by mass of the mass of blast furnace cement and water in a water / cement ratio of maximum 0.5 are mixed. A method according to claim 3, characterized in that color pigments are added and mixed. Use of a self-compacting concrete according to claim 1 or 2 for producing a concrete layer ( 4 ), wherein the self-compacting concrete on a surface to be coated ( 1 ) of a component ( 2 ) is applied. Use according to claim 5, characterized in that at a predetermined distance from the surface to be coated ( 1 ) of the component ( 2 ) a formwork ( 3 ) and the self-compacting concrete by filling in a cavity between the formwork ( 3 ) and the surface to be coated ( 1 ) of the component ( 2 ) on the surface to be coated ( 1 ) of the component ( 2 ) is applied. Use according to claim 6, characterized in that the formwork ( 3 ) at a predetermined distance of at least 2.5 cm to the surface to be coated ( 1 ) of the component ( 2 ) is arranged. Use according to claim 6 or 7, characterized in that a formwork ( 3 ) with a structured surface ( 5 ) at the predetermined distance to the surface to be coated ( 1 ) of the component ( 2 ) is arranged. Use according to any one of claims 5 to 8, characterized in that the self-compacting concrete is placed on a vertically oriented surface ( 1 ) of the component ( 2 ) is applied.

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