SK92495A3 - Bonding mixture with finely ground cement, method of manufacture and device for carrying out this method - Google Patents

Abstract

A dry mix, for producing a cement suspension for filling and/or injecting pore spaces and cavities in loose rock or cavities and/or cracks in rock or in concrete components, is in the form of a ready mix containing a sulphate additive-free finely ground clinker and/or smelter sand powder; additives such as for example bentonite, trass highly dispersive silica acid or similar know additives and admixtures such as liquiding compositions, solidification delayeds, solidification accelerators, compositions for water retention or similar known compositions. The entire homogeneous dry mix has a continuous graduated particle distribution with sieve pass values of d95 = 24 (preferably 16) microns and d50 = 7 (preferably 5) microns.

Description

Technical field

The invention relates to a binder mixture with finely ground cement for the production of cement suspensions for filling and / or injecting, for example, porous spaces and hollow spaces in loose rocks or hollow spaces and / or cracks in rock rocks or concrete building elements or the like. The invention further relates to a process for the production of a binder mixture with finely ground cement and to an apparatus for carrying out the process.

BACKGROUND OF THE INVENTION

Fine-ground cements are very fine-grained hydraulic binders with a consistently and narrowly graded grain size and a limitation of the largest grain size. The properties and use of finely ground cements are regulated, for example, in the Merkblatt für Einpressarbeiten mit Feinstbindemitteln in Lockergesteinen (Bautechnik 70, [1993], workbook 9, Ernst & Sohn, pp. 550-50).

560, and ZTV-RISS 93, Verkehrsblatt-Document B 5237, Verkehrsblatt publisher).

The terminology in both of these works is not uniform. Merkblatt uses the term finest binder and ZTV-RISS uses finely ground cement. In the US literature, micro-fine Portland cements are discussed, see US-PS 5,106,423. In particular, the term finely ground cement, which is also used in the relevant literature (Concrete 1/94, pp. 12-16, Felsbau), will be used in the following. 11 (1993), No. 6, Sonderabdruck, Bauingenieur 67, [1992], pp. 499-504).

According to the regulations, the finely ground cement for the production of cementitious suspensions should be> 95% 'at a mesh size of 16 μιη (0.016 mm) and be made with suitable additives and admixtures. The terms and contents of the admixture and admixture are defined in Zement-Merkblatt . BB 3 / BB 1.93 / 20.

As filler material for filling and / or injection, a cement slurry is used, which is essentially made on site. This cement slurry consists of at least two components delivered in containers, that is, a container containing finely ground cement and additives and a container containing admixtures (Gyôrgy Iványi,

Walter Rosa: Fullen von Rissen und Hohlräumen im Konstrukt ionsbau mit Zementsuspensionen,

Betón- und

Stahlbetonbau [1992], workbook 9, p. 224-229;

Helmut Sager a

Holger Graeve: Einsatzmôglichkeiten zementgebundender Injektionssysteme

Concrete 1/94, p.

to 16).

The success of the filler injection is dependent, for example, on the rheological properties of the cementitious slurry and on the mechanical-technological properties of the hydrated materials in the cavities or cracks. Appropriate grinding of the finely ground cement by intensive mixing and proper admixture of the necessary ingredients in the sequence prescribed by the finely ground cement manufacturer is necessary. Fixed. 2 and the liquid components supplied in containers and intended for the production of filling material are supplied by the manufacturer as individual components and must be stored on site in these containers according to regulations, with great care to be taken with great care regarding storage conditions and adherence to mixing mixing operations so that cementitious suspensions can be prepared by a skilled person.

DE 40 13 871 A1 describes precisely a sequence of mixing operations for the production of a cement slurry of finely ground cement and admixtures such as plasticizers, blowers, swelling agents, solidifying retardants and water retention means, and. according to claim 2, demineralized water is required. Aluminates and bentonites should be included as blowing agents.

According to U.S. Pat. No. 5,106,423, a certain order of mixing operations is also prescribed (column 2, lines 37 to 56). According to this specification, the mixtures can also be composed of particularly finely ground slag and, in particular, finely ground cement, where the fineness of the substances can be varied according to special requirements (column 7, lines 8 to 26). In addition, internal additives of the same grain size can be used (column 7, lines 38 to 46).

The supply and storage of components in containers, such as drums, as well as the disposal or disposal of such containers, are measures that make the production of filling material very expensive. Moreover, in many cases it is not possible to sufficiently guarantee the prescribed handling and mixing of the individual components on site, and very expensive and precise monitoring conditions are required. In addition, it has been found that, even if the known milling methods for finely ground cement are adhered to, the quality of the cement slurry, and in particular the hydrated material resulting from this cement slurry, can vary widely from container to container. The causes of this have so far been unknown.

SUMMARY OF THE INVENTION The object of the invention is therefore to simplify the production of filling material at the construction site, while at the same time guaranteeing the prescribed properties of the filling material and of the hydrated material at no extra cost.

SUMMARY OF THE INVENTION The invention does not and / or injects torsion and cavity cavities and / or

This is accomplished by a finely ground cement binder mixture for the production of cementitious slurries for filling, for example, porous seams of loose rocks or cracks in rock rocks in concrete building elements or the like in a finished dry mix containing finely ground sand or a mixture of bentonite, similar known _F x, Christ, such as ztekuťovacie means of delay solidification, curing, water retention, or similar known area the dry uniform mixture, of a water, which powder metallurgical fine soil, such as SELI silica rozrobí only zlinok or and prísadisperznú The ingredients, and the admixture of the admixture, of the invention are characterized by a constant d95 <24 μπι and a graded grain size with dSO <

μΐϋ.

mixture of podsitným

The binder is composed of a ready-to-use, dry mix intended for the factory and specially prepared from finely containing all the necessary peculiarly used fineness of grinding, and dispersibility in the dry mix must only be in the prescribed quantity.

mixture intended for processing mixed under conditions Danger of accidental error in gravimetric and / or finely ground cement (processing) ready to use, which ground cement and which kits and admixtures needed those, in particular with the same or matched grain size, good de and high reactivity, construction site with water on

The invention therefore relates to a dry bath, which can be easily controlled on the construction site, fused with stirring at the construction site or by volumetric alignment. In addition, the waste sequence of the nents, which results from a major change of the invention in accordance with the determined fineness, is an individual component of keeping to the needs of mixing individual compoments while failing to observe this in quality. The method by composition of the dry milling and the grain size of the batches according to the premix according to the mixture allows for the precise dosing of all components, such as finely ground zinc and / or finely ground compacted sand, as well as dry additives such as additives and admixtures. The dry composition of the invention requires no demineralized water. It may also be crushed with residual chloride-containing water corresponding to Table 1 in the Residual Water Directive of the Concrete Production Regulations using residual water, residual concrete and residual mortar (issued in October .5

1991) of the German Reinforced Concrete Committee (Deucher AusschuB fur Stahlbeton). Due to the harmonized recipe, the properties of the suspensions influenced by processing as well as the mechanical and technological properties of the hydrated material are virtually independent of the water quality.

Preventing processing errors in the preparation of the suspension mixture according to the present invention is of decisive importance, for example, in the acceptability and success of injection measures with finely ground binders, since repetition of these injection measures to replace previously injected mismatched filler material with insufficient properties is generally uneconomic. In addition, the use of the dry mixes of the invention provides economic benefits in filling, storage and transport as well as in the disposal of possible shipping containers.

According to the invention, the binder mixture with the finely ground cement comprises finely divided powder or powders, dry admixtures and optionally dry additives. The finely ground powder consists of finely ground Portland cement zinc (it is the finest ground Portland cement yen) or a mixture of finely ground Portland cement zinc and finely ground dense sand (it is the finest ground dense sand) or only finely ground dense sand plus solidification accelerator or also a hydration exciter. Preferably, bentonite is used as an additive. Admixtures are essentially liquefying or dispersing agents, solidifying agents, water retention agents, solidifying agents and swelling agents.

.6

The amounts of the additives to the finely ground line or to the mixture of finely ground zinc and finely ground compact sand or finely ground compact sand are very precisely and reproducibly matched to each other, preferably all essential components having a grain size d95 <

pm, in particular 'd95 <16 μΐη and d50 <7 μπι, in particular d50 <δμπι, and in particular have a ratio d50 to d95 = 0,33 ±' 0,04 (d95 = = grain diameter at 95% by weight of the substrate, d50 = = diameter of the grain at 50% by weight of the base).

In particular, if these conditions are observed, it is possible to optimize the effect of an admixture. The effect of the amount of additive, for example a liquefying agent, on the properties caused by the processing of the cement slurry from the binder mixture with finely ground cement with a water-binder ratio of 0.7 is apparent from the enclosed FIG. 2. Curve curves mean that, even with slight deviations of the liquefying agent from the predetermined mixing ratio, the rheological properties of the suspension are decisively determined, which decisively determines the success of the injection. In doing so, the initial viscosity of the suspension is relatively slightly affected by increasing the proportion of liquefaction agent from 2 to 4% by weight. 2 indicated by the Marsh time at time t = 0; however, the subsequent viscosity evolution during the processing time of the fresh mixture is subject to a significant dependence on the dosage of the liquefying agent. The professional application of cementitious suspensions can then only be expected if both the starting viscosity and the viscosity after the processing time have been optimized by selecting a suitable flowing agent with a coordinated weighing.

When optimizing the admixture dosage, the impact of additives on the strength of the hydrated suspension must be taken into account at the same time, so that it can meet the material requirements resulting from statically effective repair measures. The results of the compressive strength tests on prismatic test specimens shown in Table 1 below show that an overdose of liquefaction agent at 5% by weight already leads to a loss of initial strength. With a liquefaction agent content of 6% by weight, no compressive strength can be measured on the completely insufficiently strengthened suspensions.

Table 1

Initial strength of cement slurries (water-binder ratio - 0.6) depending on the weight of the additive.

weighing admixture [% by weight] compressive strength after 2 days [N / mm ² ] 4% 20.8 6% 18.9 6% immeasurable

It has surprisingly been found that quality assurance and processing problems are eliminated when using multi-component systems on site, while meeting the high filler requirements, using a pre-treated dry mix with a fineness of grinding and granularity of finely ground cement to produce a cement slurry, additives and admixtures. This is achieved by adding the necessary additives and admixtures to the starting materials for the preparation of the binder mixture with the finely ground cement according to the application, depending on the application, already after the milling of the zinc or dense sand, on-site processing to prepare a ready-to-use cement slurry to add only water according to a predetermined water-binder ratio. This is made possible by the use of powder additives and admixtures with a fineness of grinding and a grain size corresponding, for example, to the finely divided powder, so that these additives and admixtures will have very good dispersibility and reactivity when mixing the dry mixture with water. The re-dispersible dry components guarantee the direct efficacy of the ingredients after mixing and rinsing water. It is surprising that not only the various m-weight ingredients, but especially the different grinding fineness and granularity, especially within the limits given, the d95 and d50 ratio effects, respectively, will produce different effects, which was examined prior to the existence of separate components in containers and prescribed sequence. mixing operations as well as the use of demineralized water. The admixtures react unexpectedly sensitively within a given range of grinding fineness so that grinding fineness and granularity can be used as parameters for predetermined properties.

Grinding, sorting, dosing and mixing devices are needed to form the dry mix according to the invention, which allow fine mixtures of the same quality to be bonded with a cement binder prior to certain production.

The essence of the process according to the invention is that the individual components are treated completely separately, up to a predetermined fineness of grinding and graininess. By means of precisely controllable dosing and mixing devices, a dry mixture is then produced by homogenization according to its predetermined chemical-mineralogical composition.

Pre-processed on-site mixing according to their mixing with water dry mixtures (intended to form up to medium-viscosity cement for processing) characterized in that stable low viscosity due to water fractionation, slurry time, chemical and mineralogical and physical specialty composition and consistency they are particularly suitable as mineral systems for injection of all kinds.In addition, the incorporation of dry mixtures after the hydrated mixture with relatively cementitious processing, pourability, penetration and due to the processing result in a low initial strength. so that these pensions are also suitable for statically effective (acting) measures, regardless of the state of the three components to be injected.

Due to the relatively high demands of the finely ground cement, there is a significant reduction in the setting process, which until now has been compensated only partially or uncontrollably by the use of additives (bentonite) or admixtures (swelling agents) known in this context. In the above-described dry compositions according to the invention, the reduction is controllable, since the finely ground cement binder contains additives and 10 admixtures whose action is controllable, but the disadvantages of reduction, namely the loss of cohesion, cannot be compensated. It has been shown in the prior art mixtures that, in particular, the degree of reduction of the fluctuations and, consequently, the uniform quality of the mechanical and technological properties of the solidified filler material is a special additional measure. by increasing the coherence of the pooled system, the rock (rock) or filler. eventually ui, nity of this associated system.

can not be guaranteed, ensure a certain use in binder mixtures. the volume of which the concrete and a certain swelling will change due to the effect of the loss on the injected material, which can be controlled or precisely at the same time.

Many so-called expandable cements are known which are based on cements of the usual composition and fineness of grinding as well as conventional swelling agents. Long-term practical experience with these expandable cement works has shown that in these expandable cements it is possible to use etringite-forming foams or calcium sulfate and aluminate with a high content of crystalline water, to achieve some assurance of the necessary properties, while known expandable cements consist of mixtures of commercial Portland cements with an aluminate-sulfate component. The properties of these known expandable cements depend on the chemical-mineralogical composition and the ratio of the amounts of the components, as well as on technological factors such as consistency and storage conditions or the like. Despite extensive experience in the practical use of these known expandable cements, there are major problems in the targeted control of the solidification structure-forming process. In the case of known expandable cements, in particular the ratio of the weight of the Portland cement fraction to the swelling target, as well as the chemical activity of the swelling target, serve as controllable influencing factors.

It has been found within the scope of the invention that, in the dry compositions according to the invention, the swelling can be controlled not only by different amounts of additives but also by a certain reactive swelling agent which produces etringite by varying the reactivity of the swelling agent at a given mixing ratio. grain and fineness. According to the invention, the reinforcement rate of the matrix of the binder mixture and the formation rate of the swelling etringite are matched to one another. For example, an aluminum-sulphate-based foaming agent is used, which consists mainly of calcium aluminate and calcium sulphate, the grain size and fineness of which are within the aforementioned grain size and fineness of grinding of the binder mixture with finely ground cement. By parameters such as grinding fineness and grain size, the swelling is controllable reproducible, so that the binder mixture with finely ground cement can meet the relevant technical requirements for the material according to the purpose of use.

Surprisingly, the etringite-forming foaming agent causes a synergetic effect by increasing the sedimentation stability of the cement slurry.

The swelling control according to the invention is particularly effective when using finely ground zinc containing calcium aluminate and calcium ferrite in very small amounts.

In the dry composition according to the invention, the blowing agent is co-ordinated with a finely ground cement binder composition which contains no blowing agent. The binder mixture with finely ground cement, containing no blowing agent, is present in an amount of 50% to 95% by weight, preferably% to 90% by weight, and a grain size d95 <24 pm, preferably d95 <15 pm, and d50 <7 pm, preferably d50 íη, and preferably with a d50 to d95 ratio of - 0.33 ± 0.04, mixed with a swelling agent, for example based on aluminate sulfate, preferably consisting of calcium aluminate and calcium sulfate, in an amount of 5% to 50% %, preferably 10% to 30% by weight, preferably of less or equal fineness and granularity, wherein the homogenized whole mixture has a particle size d95 < 24 μη, preferably d95 < 16 pm, and d50 < 7 pm, preferably d50 <

pm, and the ratio d50 to d95 = 0.33 ± 0.04.

In order to detect a predetermined different swelling effect in the fine-cement cement binder mixtures according to the invention, the binder mixture is first produced in batches having different grinding finenesses and grains predetermined, and then the hardening rate of these batches is determined. determined by varying the fineness of grinding and the granularity, then it can determine the etringite formation rate of these batches. Mixtures having a predetermined swelling rate are then determined from the determined strength rates and etringite formation rates, followed by preparation.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the accompanying drawings, in which: FIG. 1 shows schematically an apparatus for producing a dry mixture to be treated according to the invention, FIG. 2 is a graph of the amount of fluidizing agent added; FIG. 3 shows a graph of grain size, FIG. Fig. 4 is a graph of the reaction time of the binder mixture with finely ground cement with swelling agent over time; 5 grit size of the binder mixture with finely ground cement and the foaming agent.

Examples of embodiments of the invention

The invention provides, in the first place, a ready-made finished composition in the form of a single dry composition which only needs to be ground with the prescribed amount of water. Mixing errors resulting from the dosing of the individual components for the production of the binder mixture with finely ground cement can no longer occur. The mixture is mixed with water in a high-performance mixer. During mixing, finely ground dry admixtures can immediately develop their action. The dry blend can be produced at any time often with the same composition and the same quality. This is due to the fact that the ingredients need not be ground together with the cementitious compound, that the ingredients must preferably have the same or higher fineness and a coarse grain size, and that the ingredients within this fineness range are very intense by having relatively small differences in the amount of ingredients (see Fig. 2) and in grain size and fineness will cause large differences in the desired effect. The amount of additives is preferably in the range of from 2% to 5% by weight (excluding blowing agents).

Usually, the finely ground cement is ground by Portland cement sulfate by separating the cement from the supply of the finely ground cement. In doing so, it separates the proportion which, within the scope of the invention, finely delivers the fact that the pellets supply the same course of the entire line and the respective only at least mleked expression carrier bears that proportion to the pneumatic corresponds to the requirements. Z to d95.

, this method is the underlying cause of not having supplied the ignorance of this cause attempts have been made to remedy this deficiency by creating mixtures and prescribing a particular sequence of mixing operations, but this has not led to sufficient results. Only a particular fine grinding of cement zinc into fine powder and compacted sand as well as fine powder, provided that finely ground compacted sand can be contained in the binder mixture with finely ground cement, as well as the use of additives or admixtures, in particular of at least equal fineness and graininess the pre-storage of all components for the assembly of binder mixtures with finely ground cement allows precise dosing of the components and, after homogenization, also guarantees a certain quality of the filler material or cement slurry and the solidified product. According to the invention, it is essential that dry additives of at least the fineness and granularity of the finely ground cement binder mixture are used, or else the finely milled cement binder mixture generally comprises the desired fineness and grain size, the admixtures may be coarser but included in the grain distribution. The resulting binder mixture has a desired grain size. If no admixtures with the required fineness and granularity are available on the market, these admixtures are produced separately. Otherwise, these admixtures, if available on the market with varying fineness and granularity, must be suitably selected. Surprisingly, the admixtures, especially in the finest ground form, have a special, previously unknown, reaction behavior with the finely ground binder mixture and can guarantee the desired injection quality, while ensuring that a binder mixture of finely ground cement of defined quality is also available, that is, defined in terms of its components and its fineness and granularity. This was not possible by the usual dust-off extraction in the grinding of normal cements because, as found in the invention, the dust-off products have a fluctuating composition, which is probably due to the separation during the dust-off. For example, spilled products are uncontrollably enriched with certain mineral phases, for example, sulphates.

By means of the apparatus shown schematically in FIG. 1, the fine-cement binder mixtures according to the invention are produced. The apparatus consists of a mill 1, to which clean portland cement zinc is fed through the conveyor path 1a, which is ground into a fine powder in the mill 1. The finely ground zinc is conveyed via conveyor tracks 18, 2a to a storage silo 2. In the same cleaned mill 1, into which conveyor lane is supplied with granular sand, this dense sand is ground to a fine powder which is conveyed via conveyor tracks 18. 3a into a storage silo 3. From the conveyor track 18 a portion of the ground material is conveyed by conveyor track 18a to a cement plant for the production of, for example, normal Portland cement. In the storage silo 4, finely ground bentonite is pre-stored and fed to the storage silo 4 via a conveyor track 4a. Material is separated from the storage forces 2, 3, 4 separately by conveying tracks 2b, 3b, 4b, which is sorted in the pneumatic classifier 5, the same pneumatic classifier 5 being provided for each material flow in succession (not shown). Likewise, be used another mill, the desired efficiency always after cleaning - it is used material or for each stream pneumatic screening machine compact sand can Number of mills is controlled by the equipment.

special for grinding

In the pneumatic sorting in the pneumatic classifier 5, the finely ground material with a predetermined fineness of grinding and granularity is separated and conveyed by the conveyor path 5a by the blower 6 to the respective conveying path 1 ', 8a, 9a and thereafter to the respective silo 1', 8, 9 1 'contains, for example, finely ground zinc, silo 8 finely ground dense sand, and silo 9 contains bentonite with a specified grinding fineness and grain size.

The coarse material is always discharged from the pneumatic classifier 5 via the conveying path 5b, 18a, 19a to the intermediate glass

1?

a conveying force 18, for example for finely ground zinc, and an intermediate storage force 19 for finely ground dense sand, from where the conveying path 1b, which leads to the conveying path 1a, is returned to the mill 1 again.

In the case of bentonite, the coarse fractions are discarded via the conveyor line 20, or they are diverted for other uses. In addition to the forces 7, 8 and 9, further additive silos are placed, for example silos 10, 11 and 12, which each contain the ingredients and a predetermined grinding fineness and graininess.

From the forces 7 to 12, the finely ground material is conveyed through the conveying tracks 7b, 8b, 9b, 10b, 11b, 12b by means of dosing devices (not shown) and fed to the main scales 13, for example in the form of a weighing container. From the main scales 13, the finely ground material is fed via a conveying path 13b to a mixer 14, for example a plow mixer, in which the finely ground material is homogenized to a dry mixture. Subsequently, the finished dry mixture is dosed directly into the bags or is conveyed via the conveying path 14b to the storage silo 15, from which the filling of the wagons with the finished mixture is produced via the conveying path 15b.

In order to facilitate homogenization, the addition of the additives can also be carried out in groups, for example by filling the common pre-scales 16 with two additives, for example from silos 11 and 12, immediately after this mixture is fed to the main weights 13. each pre-weight 16 is assigned to each force, as shown in Example 1a and 10.

In the process according to the invention, the cement zinc is ground in the mill 1 without an additive, in particular without a sulphate carrier. This powder and the finely divided powder therefore do not contain any sulfate components. For the production of binder mixtures with finely ground cement, with or without swelling agent, grinding of Portland cement zinc is equally free of sulphate, whereby in one silo, for example in silo 10, the foaming agent is pre-stored, or in silo 11 and silo 12 is pre-stored one component for assembling the foaming agent, which consists of two substances which are then added as defined.

Likewise, the sulphate carrier, intended to influence the reaction of the finely ground zinc, is pre-stored separately in some silo and is usually added already during the milling of the zinc.

Of course, the device according to the invention for the production of dry mixtures has as many forces as the components or proportions, respectively, of the dry mixture according to the invention can or should contain.

By means of the device according to the invention, a dry mixture with certain components can be assembled in predetermined amounts with a predetermined grain size and fineness of grinding, so that the action of these components in the suspension is controlled in a targeted manner. Irregularities in the quality of the filling material are thus avoided.

In FIG. 3, the grain sizes curves KV1 to KV3 are shown. The grain size curves KV1 to KV3 show, for example, the grain sizes of the finely divided cement binder mixtures according to the invention. The curves KV4 to KV6 lie outside the required grinding fineness and granularity for the finely ground cement binder mixture according to the invention. However, it is within the scope of the invention to add additives, in particular swelling agents, to be used with grain sizes according to curves KV4 to KV6 as long as the finished product, i.e. the finished dry mixture, corresponds to the grinding fineness and grain sizes according to curves KV1 to KV3. Accordingly, for example, a coarse additive according to the curve KV6 may be added in an amount which displaces the binder mixture with finely ground cement with a grain size of the curve KV1 displaced into the grain area of the curve KV3. Especially in the production of targeted and possibly reproducible, swellable binder mixtures, this possibility can be utilized, since the swelling rate can thereby be particularly effectively defined in a defined manner.

In FIG. 4 shows, for example, the determination of the etringite formation rate, or the etringite formation rate, over a period of time, and the course of the development of consolidation of a finely ground cementitious binder composition according to the invention. The formation of etringite by blending of the swelling agent (curve 1), which causes the solidifying suspension to swell, is aligned with the progressive strengthening of the binder mixture with the finely ground cement so that it coincides with the beginning strength development (curve 2 at this point) and continues further while the binder matrix is still elastically plastically deformable, similar to young concrete.

According to the invention, the swelling rate can be controlled specifically by both the amount of blowing agent added and the fineness and granularity of the blowing agent. These contexts will be explained in more detail in the following examples.

Example 1. In FIG. Fig. 5 shows the granularity of the finely ground cement binder without the swelling agent and the granularity of the swelling agent. The following Table 2 shows characteristic granularity values of exemplary selected finely ground cement binder without swelling agent and characteristic granularity values of the swelling agent.

Table 2

Characteristic grain size values of exemplary binder mixtures with finely ground cement and characteristic grain size gradients characteristic value specific surface area d50 d95 d50 / d95 'binder mixture with finely ground c without blowing agent

8000 cm ² / g

4.5 pm pm

0.32 swollen dlo

10000 cm ² / g

2.5 μπι

7.5 pm

0.33

The effect of the mixing ratio of the finely ground cement binder mixture without blowing agent and the blowing agent on the swelling ability of the finely ground cement binder mixture is shown in Table 3,

Table 3

Effect on weighing of components on the swelling ability of a binder mixture with finely ground cement

proportion of component A (% by weight) 90 80 70 the proportion of component B (% by weight) 10 20 30 expansion 0 0,126 0,406 (Mm / m)

Component A: Binder mixture with finely ground cement without swelling agent (specific surface 8000 cm ² / g).

Component B: swelling agent (specific surface 10000 cm ² / g). ·

It can be seen from Table 3 that, at a predetermined fineness of component A and component B, the swelling ability of the filler material can be controlled by the mixing ratio of the components.

Example 2

In this example, the effect of the fineness of the swelling agent on the ability to swell the binder mixture with finely ground cement is explained. In order to illustrate the effect of the fineness of the swelling agent on the swelling ability of the finely ground cement binder mixture according to the invention, the fineness of the finely ground cement binder mixture 22 is initially given without swelling agent (component A). The mixing ratio of both components is component A / component B = -70 / 30.

The respective grain sizes of both components A and B are shown in FIG. The particle size abbreviations (KV) of the two components A, B shown in Table 4 below refer to the representation in FIG. Third

Table 4

Specification of components of an exemplary selected finely ground cement binder mixture according to the invention Characteristic value / components of component A (finely ground cement binder mixture without blowing agent- (blowing agent)) component B (blowing agent- (blowing agent))

specific surface (cm ² / g) 8000 6000 8000  10000 granularity (according to Fig. 3) KV3 KV4 KV3 KV2 part (% by weight) 70 30 30 30

The following Table 5 shows the effect of the fineness of the swelling agent on the swelling ability.

Table 5

Influence of the fineness of the swelling agent on the swelling ability of the binder mixture with the finely ground cement according to the invention

component A KV3 (8000 cm ² / g) KV3 (8000 cm ² / g) KV3 (8000 cm ² / g) component B KV4 KV3 KV2 (6000 cm ² / g) (8000 cm ² / g) (10000 cm ² / g) mixing ratio 70:30 70:30 70:30 expansion (mm / m) 3.98 2.13 0,406

It follows from this example that by determining the fineness of the binder mixture with the finely ground cement without the swelling agent and the swelling agent, it is possible to control the swelling ability of the binder mixtures with the finely ground cement according to the invention. The swelling ability of the binder mixture with finely ground cement decreases with increasing fineness of the swelling agent. Therefore, in particular, the swelling ability of the finely ground cement binder mixtures can be controlled by the fineness of the components so that the finely ground cement binder mixtures can be produced which contain or also do not contain a blowing agent, i.e. in the latter case binder mixtures without extensibility. for example, a swelling-free material is always required if the use of a swelling filler material could lead to a disruption of the structure in the injected building element due to the pressure resulting from the swelling of the swelling material.

The swelling agent, as mentioned above, preferably consists of calcium aluminate and calcium sulfate. These components are milled separately except for a predetermined different fineness and granularity and subsequently the etringite formation rates are determined. The weight ratio of calcium aluminate and calcium sulphate is determined with respect to stoichiometric ratios for complete etringite formation. Likewise, the cementitious mixtures with the finely ground cement are assembled with different finenesses and granularities, and the development of strength is subsequently determined. From the determination of strength development and from the rate of etringite formation, a mixture of components is then formed which guarantees a certain degree of swelling. This mixture is then assembled as a dry mixture in a plant according to the invention and transported to the construction site.

The detection of the reaction effect of fineness and granularity as well as finely ground zinc, finely ground compacted sand and mixtures thereof as well as additives, in particular blowing agents, enables the production to be technically and without great expense responding directly to various requirements in terms of specific use by it either arranges several forces for one component, in which the component always has different fineness and granularity, or by adjusting the grinding units and pneumatic separators accordingly from batch to batch. Since the silos are combined with metering devices, the composition of the dry mixes for cementitious suspensions, or for products solidified from cementitious suspensions, can be realized in a controlled manner with differently defined and reproducible properties, in particular with respect to swelling, defined fineness and granularity. This reduces the user load significantly. Compound inspection has been relocated to a production plant where it can be accomplished professionally and easier.

Suitable blowing agents for the finely ground cement binder mixture according to the invention are, in particular, aluminum sulphate, electrocement plus gypsum, calcium aluminate plus gypsum, aluminum powder plus an aluminate component as a hydration exciter plus gypsum.

Claims (35)

1. Binder mixture with finely ground cement for the production of cement suspensions for filling and / or injecting, for example, porous spaces and hollow spaces in loose rocks or hollow spaces and / or cracks in rock rocks or concrete building elements or the like in the form of a ready-mixed dry mixture; which is ground only with water and which contains finely ground zinc or finely ground compacted sand or a mixture thereof, as well as additives such as bentonite, shakes, highly disperse silicic acid or similar known additives, and admixtures such as liquids, delayers solidifying agents, solidification accelerators, water retention aids or the like, known admixtures, the whole of the homogeneous dry mixture being characterized by a stable and graded grain size with a d95 <24 μπι and d50 <7 μπι. The fine-cement binder composition according to claim 1, characterized in that the undersize has d95 values <16 µπ and d50 <5 µm. The finely divided cement binder composition according to claim 1 and / or 2, characterized in that the ratio of the undersized values is d50 to d95 = 0.33 ± 0.4. The fine-cement binder composition according to one or more of claims 1 to 3, characterized in that it contains 5% to 95% by weight of finely divided compacted sand, based on the finely ground zinc. The finely ground cement binder composition according to one or more of claims 1 to 4, characterized in that it comprises an accelerator for finely ground compacted sand with the same or finer fineness and granularity as compared to finely ground compacted sand. The fine-cement binder composition according to one or more of claims 1 to 5, characterized in that it contains a condensate of naphthalene sulfonate with formaldehyde as a powder flowing agent. Fine-cement binder mixture according to one or more of Claims 1 to 6, characterized in that it contains admixtures, with the exception of the blowing agent, in amounts of 2% to 5% by weight. The finely divided cement binder composition according to one or more of claims 1 to 7, characterized in that it contains an etringite-forming swelling agent which during the development of the strength of the finely divided cement binder mixture causes, at the time of filling and / or injection. yet an elastically plastically deformable state of the matrix of the binder mixture with finely ground cement increment volume. The fine-cement binder composition according to claim 8, characterized in that: . 28th it contains calcium aluminate and calcium sulfate as a swelling agent. The finely divided cement binder composition according to claim 8 or 9, characterized in that the finely divided zinc is free of calcium aluminate and calcium ferrite. The finely divided cement binder mixture according to one or more of claims 8 to 10, characterized in that it contains a swelling agent in an amount of 5% to 50% by weight, based on the swelling-free composition. The finely divided cement binder composition according to claim 11, characterized in that it contains a swelling agent in an amount of 10% to 30% by weight. Method for producing the fine-cement binder mixture according to one or more of Claims 1 to 12, characterized in that all components, such as finely ground zinc, finely ground compacted sand, additives and admixtures in the form of fineness and granularity required according to one or several of the claims 1 to 3 are placed separately in the storage silos, the predetermined components are discharged from the respective storage silos dosed and fed to the mixer and mixed homogenously to a dry mixture in the mixer. 14. A method according to claim 13, wherein the dry mixture is conveyed to the last storage silo and subsequently dosed into bags or filled with vehicles. Method according to claim 13 and / or 14, characterized in that the Portland cement zinc is ground in a cement mill to finely ground zinc and pre-stored, then the finely ground zinc is produced to produce a finely ground zinc with a predetermined fineness and grades and finely ground zinc is pre-stored. The method according to claim 15, characterized in that the compacted sand granulate is ground in a cement mill to a finely ground compacted sand and pre-stored, and that subsequently, finely ground compacted sand with a finely determined fineness and a finely graded grain size is finely finely ground. ground compacted sand is sorted and pre-stored. Method according to claim 15 and / or 16, characterized in that the respective coarse material from the classifier is also pre-stored. The method according to claim 17, characterized in that the coarse material is metered into the respective pre-grinding. Method according to one or more of Claims 13 to 18, characterized in that the additives are ground before pre-storage. Method according to one or more of Claims 13 to 19, characterized in that the ingredients are mixed with a slightly coarser fineness and a slightly wider graded grain. Method according to one or more of Claims 13 to 20, characterized in that for forming; a reproducible volume increase (swelling) of the suspension solidified product is admixed with an etringite-forming swelling agent in an amount of from 5% to 50% by weight, based on the swelling-free composition. 22. The process of claim 21 wherein the swellable material is admixed in an amount of 10% to 50% by weight. The method according to claim 21 and / or 22, characterized in that a blowing agent is used which has a fineness and a grain size as required by one or more of claims 1 to 5. The method according to claim 21 and / or 22, characterized in that the blowing agent is mixed with a slightly coarser fineness and a slightly wider graded fineness as compared to the data according to one or more of claims 1 to 5. Method according to one or more of Claims 21 to 24, characterized in that calcium aluminate and calcium sulphate are used as the swelling agent. A method according to one or more of the claims 31st metal 21 to 25, characterized in that Portland cement zinc is ground without sulphate addition. A method according to one or more of claims 21 to 26. ' characterized in that the reproducible increment of the solidification product volume is determined by detaching (swelling) the binding strength of the binder matrix and the rate of etringite formation and then assembling the components for an optimal homogeneous mixture with respect to a defined rate of bulging. Method according to one or more of Claims 21 to 27, characterized in that the swellable substances are ground separately and pre-stored with different fineness and granularity. Method according to one or more of Claims 13 to 28, characterized in that at least one component of the dry mixture is pre-stored separately in different finenesses and grains. Device for carrying out the method according to one or more of Claims 13 to 29, characterized in that for each component of the dry mixture there is provided one storage silo (7 to 12), which is always combined with the metering device, and behind the storage forces a mixer (14) is provided. Device according to claim 30, characterized in that a weighing container (13) is arranged upstream of the mixer (14). 32nd Apparatus according to claim 30 and / or 31, characterized in that the mixer (14) is a high-performance mixer, for example a plow mixer. Apparatus according to one or more of claims 30 to 32, characterized in that at least two storage tanks, for example silos, are provided for at least one component. Device according to one or more of Claims 30 to 33, characterized in that a storage silo (15) is arranged downstream of the mixer (14). Apparatus according to one or more of claims 30 to 34, characterized in that it comprises a cement mill (1), a storage silo (2) and a pneumatic sorter (5) for producing finely ground zinc, the outlet side of the mill (1). for cement, it is connected to the inlet side of the silo (2), the outlet side of the silo (2) is connected to the inlet side of the pneumatic classifier (5) and the outlet side of the pneumatic sorter (5) is connected to the inlet side of the silo (8) cement zinc by means of appropriate conveying routes. Device according to claim 35, characterized in that it comprises a cement mill (1), a storage silo (3) and a pneumatic separator (5) for producing finely ground zinc, the outlet side of the cement mill (1) being connected to the inlet side of the silo (3), the outlet side of the silo (3) 33. is connected to the inlet side of the pneumatic classifier (5) and the outlet side of the pneumatic classifier (5) is connected to the inlet side of the finely ground sand (7) by means of respective conveying paths. Apparatus according to claim 35 and / or 36, characterized in that the outlet side of the pneumatic classifier (5) is connected via conveying tracks to the inlet side of the silo (18, 19), the outlet side of the silo and / or forces (18, 19). ) is connected to a cement mill (1) via a conveyor belt.