DE102016013793B4 - Method for producing a hydraulically setting building material suspension, and component produced with a hydraulically setting building material suspension - Google Patents

Abstract

The invention relates to a method for producing a hydraulically setting building material suspension is under the action of shear forces of a mixing tool at a speed of movement of Mischwerkzeugs of at least 5 m / s, a mass fraction of a flour grain composition having a mean grain diameter of less than 0.125 mm, the mass fraction of a hydraulic binder or hydraulic and having a latent hydraulic binder of at least 50%, and a dispersant having a weight fraction based on the mass fraction of the flour grain composition of at least 0.5% suspended with water at a mass fraction of less than 40% to at least 25% to a base suspension, the base suspension methyl cellulose ether and / or bentonite is mixed with a mass fraction of less than 0.5% and the suspension thus prepared, homogenis without further addition of water, with at least one porous light component to a building material suspension iert, wherein a mass fraction of the porous lightweight component is adhered to the building material suspension of at least 5%.

Description

The invention relates to a method for producing a hydraulically setting building material suspension. The building material suspension is preferably formed with lightweight porous aggregates and is thus suitable as a packaged lightweight material in structural engineering. Furthermore, the invention relates to a manufactured with a hydraulically setting building material component.

Microstructured lightweight concretes are of great importance because of their advantageous physical properties, in particular the reduced weight and the good thermal insulation properties in structural engineering. The advantageous properties are achieved by the use of lightweight aggregates, such as expanded clay, pumice, vermiculite, perlite, zeolites or foam glass, which usually have a high porous content. Corresponding compositions are for example DE 298 09 236 U1 or DE 34 20 462 C2 known.

Out EP 0 647 603 A1 a material formed from a water-cement mixture is known, which has a fine-pored structure. To improve the material properties, an admixture of glass fibers or carbon fibers may be provided. Also known is a use of such a material for producing a shaped body or a component.

In the production of lightweight concrete, the transport of lightweight concrete and in further processing, however, the problem arises that the water required for the hydraulic setting of the lightweight concrete water is pressed into the porous components of the lightweight aggregates and remains inside the porous components. In this case, the light concrete mixture is deprived of the necessary for the flowability of water, which leads to a deterioration processing capability. This becomes particularly clear during transport by pumping, since the pressure exerted on the lightweight concrete mixture during pumping of the pressure promotes liquid absorption of the porous lightweight aggregates, so that the flowability of the concrete mixture decreases and the pumping is made more difficult. A transport of liquid lightweight concrete by means of pumps over long distances or heights is therefore not possible or with high technical complexity.

Since the transport to the destination is usually realized by pumping, it is desirable that the flow and processing properties of light-weight building mixtures do not change or only insignificantly after the pumping process.

This problem has hitherto been counteracted by pretreating the porous fractions with water prior to admixture with the binder, so that the pores of the porous fractions can be filled with water and accordingly no more water can be taken up after admixture with the binder. However, it is disadvantageous that an excess of water is used in the overall mixing ratio, whereby the strength development and the resulting final strengths and the sustainability of the resulting lightweight concrete are adversely affected.

Due to the increased water content caused by a water pretreatment, there continues to be an increased risk of material shrinkage during hydraulic setting, as a result of which resulting stresses lead to damage in the lightweight concrete structure. A further problem is that the water not required in the production for the hydraulic setting process emerges from the pores as so-called pore water and diffuses into the hydraulically hardened cement stone, causing long-term damage to the lightweight concrete structure.

A water pretreatment of porous light components also has the disadvantage that the air in the pores is displaced, which partially offset the desired weight reduction. Furthermore, the displacement of the air leads to a deterioration of the thermal insulation properties and sound insulation properties of lightweight concrete.

It can therefore be stated that the quality of a hydraulically setting lightweight concrete is essentially determined by the water content of the starting mixture. The aim is therefore to prevent penetration of water into the pores of the lightweight aggregates.

To avoid water absorption by the porous portions of other methods are known which cause a seal or insulation of the porous lightweight aggregates.

Thus, a method is known in which a pretreatment of the porous portions is carried out with a polymer dispersion, whereby the pores are sealed, in order to prevent an entry of the water required for the hydration into the pores. Also known is a pore seal with cement paste, the lightweight aggregates are first mixed with cement paste and then dried before they are used as a mixture component. Both methods for pore sealing require an additional process step which causes an increased cost and time.

From WO 2013/004 853 A2, a three-stage process for the production of concrete is known, wherein in a first process step first water is treated. The pretreatment provides a chemical, mechanical, physical, electrical and / or magnetic activation of the water. Subsequently, the prepared material is used to produce a water-binder suspension. Finally, an additive is added to the water-binder suspension. The disadvantage of the solution known from WO 2013/004 853 A2 consists in the complicated and expensive pretreatment of the water required for the setting process.

Further disadvantages of known lightweight concrete compositions and components produced therefrom consist of a disproportionately decreasing modulus of elasticity, low bearing capacity, low point load and problems, for example, when anchoring heavy elements.

The object underlying the present invention is now to propose a flowable as lightweight material hydraulically setting building material suspension and simple and inexpensive method for providing a flowable hydraulically setting building material suspension, with which the disadvantages of the prior art can be avoided and reaches the requirements of sustainable properties can be. The object is also to propose a component of a hydraulically setting building material suspension, with the improved properties in terms of load capacity, point load and modulus of elasticity can be achieved.

According to the invention the object is achieved with a method having the features of claim 1 and a component according to claim 11. Advantageous embodiments and further developments of the invention can be realized with features described in the subordinate claims.

• - unter Einwirkung von Scherkräften eines Mischwerkzeugs bei einer Bewegungsgeschwindigkeit des Mischwerkszeugs von mindestens 5 m/s ein Massenanteil einer Mehlkornzusammensetzung mit einem mittleren Korndurchmesser von kleiner 0,125 mm,
  • • die einen Massenanteil eines hydraulischen Bindemittels oder hydraulischen und latent hydraulischen Bindemittels von mindestens 50 % aufweist,
  • • und einem Dispergiermittel mit einem auf den Massenanteil der Mehlkornzusammensetzung bezogenen Massenanteil von mindestens 0,5 % mit Wasser mit einem Massenanteil von weniger als 40 % bis mindestens 25 % zu einer Basissuspension suspendiert,
• - der Basissuspension Methylcelluloseether und/oder Bentonit mit einem Massenanteil von weniger als 0,5 % zugemischt wird

und die so bereitgestellte Suspension, ohne weitere Wasserzugabe, mit mindestens einer porösen Leichtstoffkomponente zu einer Baustoffsuspension homogenisiert wird, wobei ein Massenanteil der porösen Leichtstoffkomponente an der Baustoffsuspension von mindestens 5 % eingehalten wird.In the inventive method for producing a hydraulically setting building material suspension is

• a mass fraction of a flour grain composition having an average grain diameter of less than 0.125 mm, under the action of shearing forces of a mixing tool at a speed of movement of the mixing tool of at least 5 m / s,
  • Having a mass fraction of a hydraulic binder or hydraulic and latent hydraulic binder of at least 50%,
  • And a dispersant having a weight fraction of at least 0.5%, based on the mass fraction of the flour grain composition, suspended in water with a mass fraction of less than 40% to at least 25% to form a base suspension,
• - The base suspension methyl cellulose ether and / or bentonite is added with a mass fraction of less than 0.5%

and the thus prepared suspension, without further addition of water, is homogenized with at least one porous light component to a building material suspension, wherein a mass fraction of the porous light component is adhered to the building material suspension of at least 5%.

The building material suspension according to the invention is provided in two steps. In this case, the mass fraction of water in the base suspension provided in the first process step is less than 40%, wherein the base suspension in the second step, no water is added. According to the invention, water with a mass fraction of the base suspension in a range of less than 40% to at least 25% is used in the first step. The base suspension can be suspended at a speed of movement of the Mischwerkszeugs of at least 10 m / s, preferably at least 20 m / s.

According to the application purpose, it may be provided that in the second process step, the porous light-weight component with a mass fraction of at least 10%, preferably at least 25 %, more preferably at least 50% is used. In this case, the mass fraction of the porous lightweight component refers to the total mass of hydraulically setting building material suspension.

The quantitative proportion of the porous light component to the total mixture of the building material suspension is preferably determined by a desired minimization of the density of the building material mixture and a correlated strength of the resulting lightweight materials and the flowability required for the processing of the suspension.

In addition to the change in the water-solids ratio in the base suspension, the absorption capacity of the base suspension for porous minerals can also be increased or decreased by varying the proportions by mass of the dispersant, which can also be referred to as flow agent. The effect of the dispersant on the absorption capacity of the base suspension for porous materials is naturally dependent not only on the quality of the dispersant used but also on the nature and nature of the porous material structure. The amount of the mass fraction of the dispersant in the building material suspension has a decisive influence on the rheology of the ready mixes of the building material suspensions prepared by the process according to the invention.

According to one embodiment, in which perlite is used as the porous light-weight component, a mass fraction of water in the base suspension of less than 40% is used. In this case, the mass fraction of dispersant in the base suspension should be in a range between 1.0% to 2.0%. In a further embodiment, in which expanded clay or expanded clay sand is used as the light component, the mass fraction of the dispersant in the base suspension can be up to 10%, wherein the mass fraction of the water can be only 25%.

In principle, the light-weight component used can be a multiplicity of porous materials which can be homogenized in the base suspension and preferably do not segregate at least until the base suspension has set. However, it can also be provided that such lightweight components are used, which demix and accumulate on the outer edge of the building material mixture in order to achieve special properties of a component produced therefrom.

According to the application, the porous light-weight component may be selected from a group comprising: pumice, expandable shale, huts pumice, lava stone, pearlite, vermiculite, zeolite, expanded clay, expanded glass and expandable shale. Furthermore, it is also possible to use compositions of pumice, expanded slate, huts, lava stone, perlite, vermiculite, zeolites, expanded clay, expanded glass and expandable slate as the light component. Also conceivable is the use of synthetically produced porous materials as a lightweight component, such as plastics. Furthermore, porous materials can be used which are obtained in connection with waste recycling or waste recycling.

The flour grain composition, which is understood as meaning particles having a particle size of less than 0.125 mm, is composed of a hydraulic binder and / or latently hydraulic binder and at least one further flour meal component. As a further flour meal component, for example, limestone powder can be used. As the hydraulic binder in the flour grain composition, cement may preferably be used. Other hydraulic binders, such as pozzolans, especially trass, can also be used. Furthermore, it can be provided that a mixture of cement or cement and pozzolans, in particular, is used as a hydraulic binder.

Furthermore, at least one latently hydraulic binder, such as granulated blastfurnace or fly ash, can also be used in the mass fraction of the flour grain composition. Also conceivable are mixtures of hydraulic binders and latently hydraulic binders as part of the flour grain composition.

Preferably, it is possible to use what is known as a superplaticizer as the dispersant. However, it can also be provided that the dispersant used is polycarbonate ether, naphthalene sulfonate, lignin sulfonate, melamine resin or polycarboxylate or a composition of polycarbonate ether, naphthalene sulfonate, lignin sulfonate, melamine resin and / or polycarboxylate. Preferably, the dispersant is used with a maximum mass fraction in the base suspension of 10%.

The invention provides a method for producing hydraulically setting lightweight materials, which prevents the production of a concentrated base suspension by the way, that the water used in the mixtures penetrates into the porous lightweight component of the building material suspension.

In contrast to the conventional provision of lightweight concrete mixtures, it has surprisingly been possible with the method according to the invention to prepare building material mixtures with a low water content so that the pore volume of the porous lightweight component remains even after admixing with the base suspension and consequently the properties of the resulting building material suspension, such as Low weight, improved thermal and acoustic insulation, high strength and low Karbonatisierungstiefen be achieved.

In contrast to the methods known from the prior art, the porous light-weight component is not pretreated with water in the invention, so that the resulting building material suspension has no excess water. If necessary, a drying step of the lightweight component may be provided.

It has been found that the introduction of shear forces during the provision of the base suspension influences a water retention capacity of the base suspension. This means that the base suspension does not lose any water even under the influence of water-absorbent materials in the light-weight component and thus remains free-flowing.

By setting movement or rotational speeds of the mixing tool above 5 m / s in the first process step shear forces are effective, which cause a cleavage of the contained in the base suspension mineral constituents and also cause activation of existing and newly forming surfaces.

By activating the mineral surfaces of the flour meal portion, the processes that take place are catalyzed by the hydration of the minerals. The first process step can therefore also be referred to as activation of the components of the flour meal composition. The activation caused by the movement of the mixing tools and the subsequent or subsequent hydration of the activated surfaces causes an additional stabilization of the combination of the hydration shells with the materials in the base suspension. Characteristic of the hydration envelopes formed by the surface activation of the mineral components (the flour grain composition) is a pronounced water retention capacity of the base suspension. It was surprisingly found that the water retention capacity of the base suspension is greater, the less water is used. However, the mass fraction of water in the base suspension should not fall below 25% in order to ensure adequate flowability of the base suspension or of the building material suspension.

A water retention capacity of the base suspension achieved by the action of shear forces in the first process step reduces the diffusion of too large amounts of water into the pores of the light-weight component added to the base suspension in the second process step.

Preferably, the base suspension is provided with a rotating mixing tool. In this case, the suspension in the first process step at a rotational speed of the mixing tool of at least 900 revolutions per minute (rpm), preferably at least 1200 U / min, more preferably at least 1600 U / min are performed to those for the activation of the mineral surfaces of Flour grain composition required shear forces to achieve.

The production of lightweight materials with the aid of the base suspension has the advantage that due to the good flowability of the suspension and the resulting high ultimate strengths, a starting material in liquid consistency can be made available that can be processed and used in a variety of ways.

Disadvantages of hydraulically setting lightweight concrete known in the prior art, such as the timely change in processing capacity, the subsequent leakage of pore water in the building material matrix, too high shrinkage and low sustainability of the lightweight materials produced can with the hydraulically setting building material suspension prepared by the process according to the invention be reduced.

According to the invention, the base suspension is admixed with methyl cellulose ether and / or bentonite as stabilizer. Methylcellulose ethers and / or bentonite are used to stabilize the produced Base suspension and prevent floating of light components. In addition, the addition of methyl cellulose ether and / or bentonite additionally improves the water retention capacity, so that the pore sealing can be further improved.

The mass fraction of methyl cellulose ether and / or bentonite, taking into account the increase in viscosity occurring with the addition and a concomitant delay in the hydraulic setting of the building material suspension, does not exceed 0.5% of the total weight of the base suspension. Mass fractions of methyl cellulose ether and / or bentonite may be included in a range between 0.1% to 0.2% of the total mixture of the base suspension.

To provide a colored building material suspension, the base suspension and / or the building material suspension can be mixed with color pigments.

Preferably, the base suspension is suspended in the first step until a temperature rise of the base suspension of at least 2 ° C is reached. It has been found that with a temperature increase of at least 2 ° C activation of components of the flour grain composition is achieved.

The composition for a hydraulically setting building material suspension has one with a mass fraction of a flour grain composition having a mean grain diameter of less than 0.125 mm, which has a mass fraction of a hydraulic binder and / or latent hydraulic binder of at least 50%, a dispersant with a mass fraction of the Flour-matter composition based mass fraction of at least 0.5% and water with a mass fraction of less than 40% to at least 25% provided base suspension in which methyl cellulose ethers and / or bentonite is added in a mass fraction of less than 0.5%, in the Base suspension without further addition of water is homogenized at least one porous light component, wherein a mass fraction of the porous light component is at least 5%.

The porous light-weight component may be selected from a group comprising: pumice, expandable shale, huts pumice, lava stone, pearlite, vermiculite, zeolites, expanded clay, expanded glass and expandable shale. As a lightweight component, however, may also be obtained from waste porous materials or synthetically produced porous materials such as plastics.

Depending on the application, the porous light-weight component may be present in a proportion by mass of at least 10%, preferably at least 25%, particularly preferably at least 50%. In this case, the mass fraction of the porous light component relates to the total mass of the composition.

According to one embodiment, cement and pozzolans, in particular trass, may be present as hydraulic binders. Slurry sand and / or fly ash may be present as a latent hydraulic binder. Furthermore, a mixture of hydraulic binder and latent hydraulic binder may be included in the flour meal composition. The flour grain composition is formed with a mass fraction of at least 50% of a hydraulic binder and / or latent hydraulic binder. The remaining mass fraction of the flour grain composition may be formed with limestone flour.

As a dispersant Superplaticizer is preferably included. Further, as a dispersant, polycarbonate ethers, naphthalene sulfonate, lignin sulfonate, melamine resin or polycarboxylate or a composition of polycarbonate ether, naphthalene sulfonate, lignin sulfonate, melamine resin and / or polycarboxylate may be contained. Preferably, the dispersant is included with a mass fraction of the base suspension of not more than 10%.

According to an advantageous embodiment, the composition may contain methyl cellulose ethers having a mass fraction in a range between 0.1% to 0.2% based on the base suspension.

Furthermore, color pigments can be present in the composition according to the invention in order to be able to produce colored components.

According to the application, the composition according to the invention may have a water-cement value of less than 0.4, preferably less than 0.3.

Furthermore, the invention comprises a component or component element which is produced with a building material suspension provided by the method according to the invention. For the manufacture of components or Component elements, the building material suspension according to the invention can be poured or pumped into a mold or formwork. It may be provided that the component has a preferably alkali-resistant glass fiber reinforcement and / or a carbon fiber reinforcement. Reinforcement made of fiberglass or carbon fiber has the advantage that components or component elements can be provided which are much lighter than conventionally produced components.

The invention will be explained in more detail by means of exemplary embodiments.

• Tabelle 1: eine Übersicht eines Mischungsbeispiels 1 einer Zusammensetzung für eine hydraulisch abbindende Baustoffsuspension
• Tabelle 2: eine Übersicht der Eigenschaften einer mit dem Mischungsbeispiel 1 nach dem erfindungsgemäßen Verfahren hergestellten hydraulisch abbindenden Baustoffsuspension
• Tabelle 3: eine Übersicht über vier weitere Mischungsbeispiele 2 bis 5 zur Bereitstellung hydraulisch abbindender Baustoffsuspensionen
• Tabelle 4: eine Übersicht der Eigenschaften (Druckfestigkeiten und Setzfließmaße) von mit den Mischungsbeispielen 2 bis 5 nach dem erfindungsgemäßen Verfahren hergestellten hydraulisch abbindenden Baustoffsuspensionen

Show it:

• Table 1: an overview of a mixing example 1 of a composition for a hydraulically setting building material suspension
• Table 2: an overview of the properties of a hydraulically setting building material suspension prepared with the mixing example 1 by the method according to the invention
• Table 3: an overview of four further mixing examples 2 to 5 for the provision of hydraulically setting building material suspensions
• Table 4: an overview of the properties (compressive strengths and setting flow rates) of hydraulically setting building material suspensions prepared by mixing Examples 2 to 5 according to the method of the invention

Table 1 Mixture Example 1 flour composition Cement CEM I 52.5 R 450 kg = 150 dm ³ limestone 150 kg = 56 dm ³ water water 230 kg = 230 dm ³ dispersants Superplaticizer 10 kg = 10 dm ³ base suspension 840 kg = 446 dm ³ Density of the base suspension 1833 kg / m ³ Porous lightweight composite Expanded clay sand SMF 0/4 mm 720 kg = 554 dm ³ th (Dry)

In the preparation of a hydraulically setting building material suspension according to the inventive method according to an embodiment corresponding to the mixing example 1 in a first step, first the individual components, water, a flour grain composition of cement CEM I 52.5 R and limestone flour, and dispersants to provide the base suspension such Follows. First, 230 kg of water and 10 kg of the superplasticizer dispersing agent are introduced into the mixer with a rotating mixing tool.

Subsequently, 450 kg cement CEM I 52.5 R is added as a hydraulic binder and 150 kg of limestone powder. All additions are made during the ongoing mixing process, that is to say with a rotating mixing tool. The rotational speed of the mixing tool is steadily increased during the suspension process up to 1600 rev / min. Alternatively, the speed of movement of a mixing tool can be increased from at least 5 m / s to 20 m / s.

The entire mixture or suspension is suspended after addition of all components until the base suspension has reached a temperature increase of at least 2 ° C. in relation to the temperature of the components before addition to the suspension mixer.

The base suspension obtained in the first process step has a density of 1833 kg / m ³ .

Subsequently, with slowly rotating mixing tool, that is to say at rotational speeds below 300 rpm, the proportion of the porous light component, which according to the mixing example 1 is expanded clay sand SMF 0/4 mm (grain size up to 4 mm) with a dry weight of 720 kg and a volume of 554 dm ³ , in the suspension mixer with the contained therein Base suspension filled and homogenized. The properties of the hydraulically setting building material suspension provided are shown in Table 2 below. Table 2: Properties building material suspension Densified homogenized building material suspension 1560 kg / m ³ Water - flour grain ratio 0,383 Compressive strength after 10 hours > 13 N / mm ² Compressive strength after 28 days > 55 N / mm ² E-modulus after 28 days > 18 N / mm ² Bending tensile strength after 28 days > 4.0 N / mm ²

As can be seen from Table 2, the homogenized hydraulically setting building material suspension has a density of 1560 kg / m ³ . The building material suspension produced in this way has a compressive strength greater than 13 N / mm ² after 10 hours. After 28 days, the hydraulically set building material suspension reaches a compressive strength of more than 55 N / mm ² , a modulus of elasticity of more than 18 N / mm ² and a bending tensile strength of more than 4.0 N / mm ² .

According to the invention, the base suspension methylcellulose ether is added or admixed for additional stabilization. The addition of methyl cellulose ether can lower the surface tension in the suspension and additionally improve the water retention capacity.

Since the pore spaces of the porous light component due to the sealing effect of the concentrated base suspension can not or only partially fill with shares of water, it is possible that the hydraulically setting building material suspension prepared according to the embodiment over a period of up to 60 minutes, at Temperatures between 20 to 25 ° C, while maintaining the processing and flowability can be stored, transported and pumped.

Advantageously, it is achieved by the base suspension produced according to the invention that the base suspension itself connects with its relatively high binder content with the surface of the proportion of the porous light component and seals in this way the surfaces of the porous material. A Nachdringen of free, so-called rheological water in the cavities of the porous material (the light component) is thus difficult. Consequently, the admixture of the porous light component, the rheological behavior of the base suspension is insignificantly influenced, so that also mass fractions of more than 50% of absorbent materials can be mixed as a porous light component in the base suspension.

The endeavor in the production of a lightweight building material is essentially to anchor as large amounts of light porous materials in the overall mixture and thus to be able to exploit the resulting total positive effects of a lightweight construction material produced by the process according to the invention also optimal.

Another advantage of the invention is that a low water content in the base suspension has a low water-cement value of the building material suspension to follow. As a result, an improved early strength of the resulting lightweight concrete can be achieved. In addition, the low water-cement value has a favorable effect on the shrinkage behavior and on the sustainability of the lightweight construction materials produced.

After completion of the building material suspension of the base suspension and the porous lightweight component forms a concentration gradient at the interfaces of the porous material and the solidifying base suspension, since a diffusion of water fractions in the surface of the absorbent porous material of the lightweight component can not be completely prevented. As a result, at the surface of the porous material, as opposed to the suspension mass not directly absorbed, the concentration of binder, such as cement, increases. Immediately in the vicinity of the porous surface thus results in a much lower effective water-cement value. As a result, the border regions of the binder matrix are stabilized both in the development of early strengths and in the achievement of ultimate strengths and have substantially higher strengths at these areas. Thus forms the Base suspension around the porous materials of the lightweight component of a solid scaffold, which contributes to an additional stabilization of the grain strengths of the porous materials. Table 3 mixture example 2 3 4 5 cement 450 kg 500 kg 400 kg 400 kg limestone 150 kg 350 kg - - granulated blast furnace slag - - 350 kg - fly ash - - - 300 kg water 230 kg 350 kg 300 kg 270 kg Dispersant / Dispersing Agent I 5 kg 6 kg 7 kg 5 kg stabilizer 0.2 kg 0.3 kg 0.2 kg 0.3 kg Expanded clay 4/8 - - - 250 kg Expanded clay sand 0/4 720 kg - - 500 kg perlite - 300 kg 350 kg - density 1650 kg / m ³ 1520 kg / m ³ 1400 kg / m ³ 1520 kg / m ³

Table 3 shows an overview of four further mixing examples 2 to 5 for providing hydraulically setting building material suspensions.

In the production of a building material suspension according to the invention, which due to the low weight of the lightweight component expanded clay, expanded clay and / or perlite can also be referred to as weight-reduced building material suspension, according to an embodiment of the method according to the invention first the individual components, water, dispersants and then the proportions of the flour grain composition Cement, limestone meal, blastfurnace slag and / or fly ash added to provide the base suspension. The stabilizer used is preferably methyl cellulose ether. Alternatively, it may be advantageous that a clay-containing mineral, preferably bentonite, is used as the stabilizer.

According to Mixing Example 2 of the above-mentioned Table 3, 230 kg of water and 5.0 kg of dispersant, which is the dispersant superplasticizer (polycarbonate ether), are first charged to the mixer with the mixing tool rotating.

Subsequently, 450 kg of cement as a hydraulic binder as a component of the flour meal composition and 150 kg of limestone powder are added. The rotational speed of the mixing tool should initially be in the range of 600 to 900 rpm during the metering process.

After completion of the dosing of the flour meal ingredients, the rotational speed of the mixing tool is steadily increased up to 1600 rpm. Alternatively, the speed of movement of a mixing tool can be increased from at least 5 m / s to 20 m / s.

The entire mixture of the base suspension provided in this way is after mixing all components while at high speed rotating mixing tool, mainly at rotational speeds of at least 20 m / s mixed until the suspension has reached a caused by the shearing with the mixing tools temperature increase. Preferably, the temperature increase compared to the temperature of the suspension should reach a temperature increase of at least 2 ° C immediately after completion of all metering operations.

Subsequently, at a slower rotating mixing tool, that is to say at rotational speeds below 400 rpm, the proportion of the porous light component, which according to Example 2 is Blähtonsand SMF 0/4 mm (grain size to 4 mm) with a dry weight of 720 kg , filled in the suspension mixer with the base suspension contained therein and homogenized.

According to the invention, in the case of mixing example 2, proportions of 0.05% by weight of methylcellulose ether are added to the base suspension as stabilizer. The proportion of the stabilizer must be adjusted according to the total mixing ratio. Table 4 mixture example 2 3 4 5 Compressive strength after 10 hours 15.5 N / mm ² 12.3 N / mm ² 9.8 N / mm ² 16.6 N / mm ² 24 hours 26.5 N / mm ² 18.7 N / mm ² 17.4 N / mm ² 27.2 N / mm ² 28 days 46.3 N / mm ² 41.5 N / mm ² 48.2 N / mm ² 51.4 N / mm ² Modulus 22000 N / mm ² 18200 N / mm ² 18600 N / mm ² 22500 N / mm ² flexural strength 4.5 N / mm ² 4.8 N / mm ² 4.8 N / mm ² 3.8 N / mm ² Slump flow rate after 5 minutes > 100 cm > 100 cm > 100 cm > 100 cm 30 minutes > 100 cm > 100 cm > 100 cm 89 cm 60 minutes 85 cm 93 cm > 100 cm 76 cm

Table 4 shows an overview of the properties (compressive strengths and setting flow dimensions) of hydraulically setting building material suspensions prepared by mixing Examples 2 to 5 according to the method of the invention.

Claims (11)

Process for producing a hydraulically setting building material suspension, in which a mass fraction of a flour grain composition having an average grain diameter of less than 0.125 mm, under the action of shearing forces of a mixing tool at a speed of movement of the mixing tool of at least 5 m / s, Having a mass fraction of a hydraulic binder or hydraulic and latent hydraulic binder of at least 50%, And a dispersant having a weight fraction of at least 0.5%, based on the mass fraction of the flour grain composition, suspended in water with a mass fraction of less than 40% to at least 25% to form a base suspension, - The base suspension methyl cellulose ether and / or bentonite is added with a mass fraction of less than 0.5% - And the thus prepared suspension, without further addition of water, is homogenized with at least one porous light component to a building material suspension, wherein a mass fraction of the porous light component is adhered to the building material suspension of at least 5%. Method according to Claim 1 , characterized in that the base suspension at a movement speed of Mischwerkszeugs of at least 10 m / s, preferably at least 20 m / s is suspended. Method according to one of Claims 1 or 2 , characterized in that the porous lightweight component with a mass fraction of at least 10%, preferably at least 25%, particularly preferably at least 50% is used. Method according to one of Claims 1 to 3 , characterized in that the porous light-weight component is selected from a group comprising: pumice, expandable shale, ironworks, lava stone, pearlite, vermiculite, zeolites, expanded clay, expanded glass and expandable shale. Method according to one of Claims 1 to 4 , characterized in that is used as a hydraulic binder of the flour grain composition cement or cement and pozzolans, in particular trass. Method according to one of Claims 1 to 5 characterized in that is used as a latent hydraulic binder in the flour meal fraction slag sand and / or fly ash / are. Method according to one of Claims 1 to 6 , characterized in that the basic suspension of methyl cellulose ether and / or bentonite is mixed with a mass fraction in a range between 0.1% to 0.2%. Method according to one of Claims 1 to 7 , characterized in that the base suspension is suspended in the first step until a temperature rise of the base suspension of at least 2 ° C is reached. Method according to one of Claims 1 to 8th , characterized in that polycarbonate ethers, naphthalene sulfonate, lignin sulfonate, melamine resin or polycarboxylate or a composition of polycarbonate ether, naphthalene sulfonate, lignin sulfonate, melamine resin and / or polycarboxylate is used as the dispersant. Method according to one of Claims 1 to 9 , characterized in that the building material suspension color pigments are added. Component, produced with a provided according to claims 1 to 10 hydraulically setting building material suspension, characterized in that the component has a glass fiber reinforcement and / or a carbon fiber reinforcement.