CN1910025B - Method and shotcrete machine for processing shotcrete with a shotcrete machine - Google Patents

Abstract

Disclosed is a method for processing gunned concrete by means of a spraying machine (1). According to said method, additives (12) can be fed to the gunned concrete before the same is discharged from a spray nozzle (6). At least one additive (12) which contains a certain proportion of solids is mixed with water in a mixing device and is fed to the gunned concrete by said mixing device before the gunned concrete is discharged from the spray nozzle (6).

Description

Method and shotcrete machine for processing shotcrete with a shotcrete machine

technical field

The invention relates to a method for processing shotcrete with a shotcrete machine. The invention also relates to a shotcrete machine.

Background technique

Generally known some concrete spraying methods and used shotcrete machines, such as Shotcrete machine. The main difference here is between dry and wet spraying methods.

In the wet spraying method, hydraulic binders such as cement, lime or gypsum, corresponding additives such as gravel and sand and various concrete additives are already mixed with water before spraying. The wet shotcrete is then conveyed to the nozzles hydraulically in the thick flow process or pneumatically in the thin flow process. In the dense flow process, the dense flow is broken by high-pressure air before the nozzle and various accelerators are conveyed by the air flow. In the thin flow process the accelerator is also added to the shotcrete by air before the nozzle.

In the dry spraying method, dry concrete shotcrete consisting of hydraulic binders, additives and various concrete additives is added to the concrete spraying machine. The conveying takes place pneumatically in the lean flow process. Staggered delivery of water and accelerators ahead of the nozzles.

Concrete additives, in particular accelerators, which are added to the nozzles are always dosed in liquid form. Such liquid additives, in particular curing accelerators, are generally placed in the shotcrete frame or in the container of the shotcrete machine. A problem with such liquid additives, however, is the storage stability, which in many respects is not sufficient, so that the additive may not be usable after prolonged storage. Furthermore, such liquid concrete additives have a relatively large volume, so that there may be problems with feeding and feeding to the shotcrete machine.

In order to overcome stability problems, therefore, the additives, in particular the curing accelerators, are delivered in powder form to the construction site and dissolved there with water in situ. The liquid-containing curing accelerator is then conveyed from the building site to the spraying machine and used, similarly to the already liquefied curing accelerator, for spraying the shotcrete. However, this necessitates an additional work step and the processing of powdered accelerators places high demands on personnel and leads to a strong dust load. After dissolution of the pulverulent additive, liquid-containing accelerators must likewise be processed relatively quickly, since stability problems can also arise here.

Contents of the invention

It is therefore the object of the present invention to provide a method for processing shotcrete with a shotcrete machine and a shotcrete machine of the above-mentioned type to be able to process additives easily and without stability problems when spraying the concrete.

According to the invention, a method is proposed for processing shotcrete with the aid of a shotcrete machine, wherein additives can be supplied to the shotcrete before the shotcrete is discharged from a nozzle, characterized in that at least one An additive with a solid component is mixed with water in at least one mixing device and the at least one additive is delivered to the shotcrete by the at least one mixing device before being discharged from the nozzle.

The essence of the invention is that at least one additive having a solid component is mixed with water in a mixing device and that the at least one additive is fed from the mixing device to the shotcrete before being discharged from the nozzle.

Furthermore, the present invention has the advantage that, in the concrete spraying method according to the invention, concrete additives with a certain solid content, in particular in powder form, are introduced directly to the spraying machine, and there only the required amount of the additive is applied in each case. Mix directly with the corresponding amount of water. This method has lower transport costs due to the less material transported and the storage stability of the dissolved additives is no longer critical. By reducing the stability requirements, it is possible to chemically improve the additives to be used, since the stability of the individual components in the liquid state still plays only a very small role.

Furthermore, the additive quantity in the liquid additive mixture fed to the shotcrete can be adjusted very easily and can thus be adapted to the special requirements of the properties of the shotcrete being sprayed. It is also possible to produce liquid additive mixtures with a higher effective material concentration than conventional liquid additives, whereby the properties of the resulting concrete can be improved.

It is also advantageous that additives which cannot be used today due to their destabilizing effect can be delivered to the shotcrete by the method. Via the viscosity adjustment of the liquid additive mixture in the mixing device, the viscosity can be adjusted such that the additive is distributed as optimally as possible in the shotcrete.

According to the invention, there is also proposed a shotcrete machine for processing shotcrete, in which additives can be fed to the shotcrete before it is discharged from a nozzle, characterized in that a At least one mixing device for additive mixing with solid components is operatively connected to the shotcrete machine.

Description of drawings

Embodiments of the present invention are described in detail below with the aid of the drawings. Identical components are indicated by the same reference numerals in different figures. The flow direction of the medium is indicated by arrows.

In the attached picture:

Figure 1 is a schematic diagram of a shotcrete machine,

Figure 2 is a schematic diagram of a mixing device according to the invention,

Figure 3 is a schematic illustration of another mixing device according to the invention.

Detailed ways

In the drawings only the essential components are shown for a direct understanding of the invention.

A shotcrete machine 1 is depicted schematically and very simplified in FIG. 1 . Such a shotcrete machine consists of a water and compressed air supply line 2, wheels 3 with a running frame, a filling funnel 4 for conveying the shotcrete, a hose 5 and a hose connected to it. nozzle6. The hose 5 can also be made of a rigid tube, but must be elastic at least in the region of the nozzle 6 in order to apply the shotcrete. Furthermore, a further line 7 is provided on the shotcrete machine 1 , which leads into the hose in the area of the nozzle 6 . In a wet spraying method, air is conveyed via line 7 offset from the additive, and in a dry spraying method, water is conveyed offset from the additive.

A mixing device 8 for additives is also provided on the shotcrete machine 1 , which can be directly integrated into the shotcrete machine 1 or can also be connected to the shotcrete machine via lines not shown.

例如以名称销售。The mixing device 8 and the associated parts of the shotcrete machine 1 are schematically depicted in FIG. 2 . The mixing device essentially comprises a storage container 10 , a water feed line 9 and a stirrer 11 . In the storage container 10, a concrete additive 12, preferably an accelerator, is filled in powder or granular form. Some such additives are generally known, such as curing accelerators, corrosion inhibitors, liquefiers, and the like. Accelerators are especially important for shotcrete, consisting of

e.g. with the name Sale.

The container 10 is advantageously equipped with a hermetically closed cover, so that no air moisture can penetrate into the additive 12 . A metering device 13 , for example a sliding valve or a metering screw, impeller gate or the like, is responsible for metering the powdery additive 12 into the mixer 11 . If the container 10 with the pulverulent additive 12 is arranged on a weighing device 14 , it is sufficient to use a slide valve for metering. A weighing device 14 is not required if a metering screw is used as the metering device.

Water is dosed to the mixer 11 via the water supply line 9 by means of a dosing valve 15 . The water can also be temporarily stored in a container (not shown) and brought there to a given processing temperature. For mixing the water with the pulverulent additives in the mixer 11 , for example paddle mixers, dispersers or rotary stators are used. The liquid additive mixture thus produced may be a solution, a dispersion or a combination between a solution and a dispersion. This depends in each case on the solubility of the additives used. Advantageously, the dispersant with the additive of lower solubility should have a certain stability for not settling out in the event of accidental interruption of the spraying process. Complete dissolution is not necessarily required, as additives that are not readily soluble in water may also lead to good results in shotcrete.

Any amount of additives can be added to the water in the mixer. The composition of the pulverulent additive 12 in water is generally 5 to 95% by weight, preferably 40 to 80% by weight, particularly preferably 40 to 60% by weight.

Mixtures containing liquid additives can be pumped out of the mixer 11 and back into the mixer 11 via mixing means arranged in the mixer 11 through a circulation line 16, which improves mixing. A pump can also be provided in the circulation line, whereby mixing tools in the mixer are no longer necessary. Optionally, one or more heating devices not shown can also be provided in the water supply line 9, in a water intermediate storage tank not shown, in the mixer 11 and/or in the line 16, by means of which Heating the liquid additive mixture or the incoming water to a higher temperature, in particular to a temperature above 40° C., serves to improve the solubility of the powder and influence the viscosity of the liquid additive mixture.

By means of an inlet line 17 branching off directly from the mixer 11 or the circulation line 16, only the liquid additive mixture is supplied to the line 7, which supplies water or air to the nozzles, depending on the spraying method. For this purpose, a metering valve or a metering pump 18 can be provided in the supply line 17, by means of which the quantity of the liquid additive mixture delivered to the shotcrete can be regulated. In this case, approximately 2 to 15% by weight of a liquid additive mixture relative to 100% by weight of hydraulic binder in the shotcrete is fed to the shotcrete. The addition of the liquid additive mixture is thereby controlled by the spraying of the concrete and the diffusion of the hydraulic binder components contained therein.

The mixing device is operated by a computerized control and regulation system, not shown. The delivery quantity of water, pulverulent additive 12 and hydraulic binder can be determined by independent measuring device/counter or directly by means of dosing device 13, weighing device 14, dosing valve 15, dosing valve 18 and by means of The hydraulic binder achieved in relation to the amount of concrete shot delivered.

For example, the desired mixing ratio can be adjusted via the amounts of additive 12 and water fed to the mixer 11 . If a certain amount of liquid additive mixture is withdrawn from the mixer by means of the metering valve 18, the amount withdrawn can be determined by adjusting the opening time of the metering valve 18 or by means of a measuring device, not shown. In order to compensate the withdrawn quantities in the mixer, the required quantities of additive 12 and water are again supplied to the mixer 11 via the metering device 13 and the metering valve 15 . The storage volume of the agitator 11 also allows the operator to allow a period of time before refilling the container 10 if the additive is used up or if there is a failure in the delivery of water through the water input line to eliminate this failure.

The content of pulverulent additive 12 in water can also be adjusted arbitrarily to the aforementioned limit values by means of this method. This allows a quick reaction to changes in the hydraulic binder or shotcrete content.

In the method according to the invention, a large amount of liquid additive mixture is not preprocessed, wherein the volume of the stirrer 11 is generally in the range of 1 to 80 liters. By a small amount and by only liquefying the required amount of additive, in this method There is no stability problem of liquid additives in the medium. In addition, the volume of powdered additives is less than or equal to 1/2 of the volume when using liquid additives, resulting in less transportation costs and less environmental load and enables the spraying machine to has a smaller size.

In FIG. 3 the stirrer 11 and the circulation line 16 in FIG. 2 are replaced by a continuous stirrer 19 , for example an extruder. One such extruder has at least one mixing and conveying screw. As a continuous stirrer, for example, a mixing rod with mixing elements, which is arranged in an essentially horizontal hollow cylinder, can also be used. The additive delivered via the metering device 13 and the water delivered via the water supply line 9 are mixed in a continuous mixer and a solution and/or dispersion is formed analogously to the above. It is not necessary to use a metering pump 18 here, since the extruder 19 assumes the function of conveying and metering the liquid additive mixture. Since a very good mixing is already achieved by the extruder 19, a circulation line is not required. The extruder 19 is heatable to improve the solubility of the powder and to influence the viscosity of the liquid additive mixture.

Of course, the invention is not limited to the exemplary embodiment shown and described. The agitator and extruder can also be replaced by components of the same or similar function. Instead of powdery additives, it is also possible to use viscous additives or moist powders, which are mixed with water in a mixing device to the appropriate mixing content. But there may be stability issues to be aware of here. The additives used according to the invention have a certain solids content of at least 1%, preferably more than 10%, particularly preferably more than 50%, especially more than 80%.

By using several mixing devices it is also possible to process mutually incompatible additives or slightly moist or liquid additives as described above, especially such additives in powder form without stability problems, individually in different mixing devices And delivered to the concrete shotcrete. When using several mixing devices, they are arranged in parallel with one another and the liquid additive mixture is fed individually to the shotcrete or via a common line. For better mixing, the stirrer 11 and the continuous stirrer 19 can also be combined in one mixing device and connected in parallel or in series.

list of reference signs

1 Shotcrete machine 11 Stirrer

2 Pressure air input pipeline 12 Concrete additive

3 Wheels 13 Dosing device

4 Filling funnel 14 Weighing device

5 Hose 15 Dosing valve

6 Nozzles 16 Circulation pipeline

7 Lines for water or air 17 Input lines

8 Mixing device 18 Dosing valve or dosing pump

9 Water input line 19 Continuous agitator

10 storage containers

Claims (22)

1. Method for processing shotcrete with the aid of a shotcrete machine (1), wherein additives (12) can be fed to the shotcrete before the shotcrete is discharged from a nozzle (6), characterized in that , at least one additive (12) with a solid component is mixed with water in at least one mixing device (8) and the at least one An additive is delivered to the shotcrete. 2. The method for processing shotcrete as claimed in claim 1, characterized in that at least two mixing devices (8) are used in which at least two different additives (12) are processed. 3. The method for processing shotcrete as claimed in claim 1 or 2, characterized in that only the amount of additive (12) required for processing shotcrete is liquefied. 4. The method for processing concrete shotcrete as claimed in claim 1 or 2, characterized in that, the additive (12) is carried out with water in an agitator (11) or a continuous agitator (19) mix. 5. The method for processing shotcrete as claimed in claim 4, characterized in that the additive (12) mixed with water is pumped out of the mixer (11) by means of a circulation line (16) and pumped back again in the mixer (11). 6. The method for processing concrete shotcrete as claimed in claim 1 or 2, characterized in that, said additive (12) is dosed relative to water by a dosing device (13), and/or water The additive (12) is added via a metering valve (15). 7. The method for processing shotcrete as claimed in claim 1 or 2, characterized in that the liquid additive mixture is delivered to the concrete by means of a metering pump (18) or a metering valve (18) Shotcrete and adjust the amount of liquid additive mixture to be delivered. 8. the method for processing concrete shotcrete as claimed in claim 1 or 2 is characterized in that, according to the content of used concrete shotcrete and its hydraulic binder to the proportioning of additive (12) and water than adjust. 9. The method for processing shotcrete as claimed in claim 1 or 2, characterized in that the dosing ratio of the additive (12) to water and the amount to be delivered to the concrete are realized by means of a control and/or regulation unit Quantity of liquid additive mixture for shotcrete. 10. The method for processing shotcrete as claimed in claim 1 or 2, characterized in that the liquid additive mixture has 5 to 95% by weight of additive (12) components. 11. The method for processing shotcrete as claimed in claim 1 or 2, characterized in that the additive (12) has a solids component of at least 1%. 12. The method for processing shotcrete as claimed in claim 1 or 2, characterized in that a pulverulent additive is used as the additive (12). 13. The method for processing shotcrete as claimed in claim 1 or 2, characterized in that an accelerator is used as the additive (12). 14. The method for processing shotcrete as claimed in claim 1, characterized in that at least two mixing devices (8) are used in which at least two mutually incompatible additives (12) are processed. 15. The method for processing shotcrete as claimed in claim 10, characterized in that the liquid additive mixture has 40 to 80% by weight of additive (12) components. 16. The method for processing shotcrete as claimed in claim 10, characterized in that the liquid additive mixture has 40 to 60% by weight of additive (12) components. 17. The method for processing shotcrete as claimed in claim 11, characterized in that the additive (12) has a solids fraction of more than 10%. 18. The method for processing shotcrete as claimed in claim 11, characterized in that the additive (12) has a solids fraction of more than 50%. 19. The method for processing shotcrete as claimed in claim 11, characterized in that the additive (12) has a solids fraction of more than 80%. 20. Shotcrete machine (1) for processing shotcrete, wherein additives (12) can be fed to the shotcrete before the shotcrete is discharged from a nozzle (6), characterized in that one for A mixing device for mixing water with at least one additive (12) having a solid component is operatively connected to the spraying machine. 21. Shotcrete machine according to claim 20, characterized in that the mixing device (8) comprises means for delivering water (9, 15) and additives (10, 13, 14) and at least one agitator (11) and/or a continuous mixer (19). 22. The shotcrete machine as claimed in claim 20 or 21, characterized in that the at least one additive (12) is powdered and/or an accelerator.

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