KR101843048B1 - Grout Mixer - Google Patents

Abstract

The present invention relates to a grout mixer, which prevents aggregation of cement particles when cement and water are mixed while stirring to reduce grain sizes of grout, thereby enabling the grout to be injected smoothly into a structure, wherein the grout mixer according to the present invention comprises: a main body having a mixing chamber in which the cement and water are injected and mixed; a stirring unit stirring the cement and water introduced into the mixing chamber; a filter unit having a filter through which a mixture of the cement and water continuously passes through the mixing chamber by the stirring unit; and a vibrating unit vibrating the filter.

Description

Grout Mixer

The present invention relates to an apparatus for producing a grout by mixing cement and water, and more particularly, to an apparatus for mixing grout with water by mixing water and cement into a mixing chamber, To a grout mixing apparatus capable of preventing coagulation phenomenon.

Generally, when the strength of the ground is weak in the civil engineering works such as the repair and reinforcement of the structure, roads, tunnels, etc., the ground subsides or collapses causing damage to people or property. This is the most common method of reinforcing such soft ground A grouting method is used.

Grouting method is to inject grout (various kinds of cement, mortar, medicine) around foundation ground or structure and inside structure for the purpose of consolidation of ground, increase of bearing capacity, reduction of permeability, integration of ground and structure will be.

The purpose of this grout can be largely divided into three types. Firstly, there is the purpose of filling the cracks in the pores or the ground and preventing the elution of the groundwater. Secondly, the purpose of the grout is to improve the adhesion between the soil particles, There is a purpose of reinforcing the ground to increase the strength of the soft ground by the method of the present invention and the third is to fill the space formed in the ground or between the ground and the structure to prevent the displacement of the ground and the structure.

On the other hand, the grout injected into the ground during the tunnel construction acts to reinforce the foundation ground and prevent the leakage phenomenon. In order to use it in the narrow space such as the split part of the multi-layer tunnel, the grout is manufactured by mixing cement and water The size of the grout mixing device must be reduced.

However, the conventional grouting device has a problem in that it is too large to be used in a narrow space such as a branch portion of a multi-layer tunnel.

Further, in the conventional grouting device, the cement particles are agglomerated in the process of mixing the cement and water, and the size of the particles increases. In this case, when the grout is injected into the rock bed, the grout effectively penetrates into the narrow gap of the rock bed The problem that can not be done occurs.

Public Utility Model Publication No. 1998-026061 (published on August 05, 1998) Registration No. 10-1292193 (Registration date July 26, 2013) Registration Practical Utility Model No. 20-0130332 (Date of Registration September 01, 1998) Registration No. 10-1480030 (Registered on December 31, 2014)

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a cement mortar composition which is easy to be miniaturized and prevents agglomeration of cement particles when mixed with mixing of cement and water to reduce the size of the grout, Which can be smoothly injected into a structure.

According to another aspect of the present invention, there is provided a grouting apparatus comprising: a main body having a mixing chamber into which cement and water are mixed and mixed; An agitation unit for agitating the cement and water introduced into the mixing chamber; A filter unit having a sieve passage through which a mixture of cement and water continuously mixed in the mixing chamber is mixed by the stirring unit; And a vibrating unit for vibrating the screen.

According to the present invention, a mixture of cement and water is pulverized while passing through the sieve in the course of mixing the cement and water in the mixing chamber by rotating the stirring screw. At this time, since the sieve is vibrated by the vibration unit, And water can be decomposed smoothly into fine particles, so that the grain size of the grout can be significantly reduced.

1 is a perspective view of a grouting device according to an embodiment of the present invention.
2 is a cross-sectional view of the grouting device shown in FIG.
Fig. 3 is a perspective view showing a main portion of the grouting device shown in Fig. 1 projected. Fig.
4 is a plan view of a main part of the grouting device shown in Fig.
Fig. 5 is a cross-sectional view of the grouting device shown in Fig. 1,
6 is a plan view showing another embodiment of the support member of the grouting device according to the present invention.
7 is a cross-sectional view of the support member shown in Fig.
8 is a plan view of a grouting device according to another embodiment of the present invention.
9 is a cross-sectional view illustrating an auxiliary mixing unit of the grouting device shown in FIG.
10 is a graph showing particle size analysis results for a sample that has passed through a screening network of the grouting device according to the present invention and particle size analysis results for a sample that has not passed through a screening network.

Hereinafter, preferred embodiments of the grouting device according to the present invention will be described in detail with reference to the accompanying drawings.

1 to 5, a grout mixing apparatus according to an embodiment of the present invention includes a main body 10 having a mixing chamber 11 into which cement and water are mixed and mixed, (30) for continuously passing a mixture of cement and water mixed by the stirring unit in the mixing chamber (11), and a filter unit 30 as a vibrating unit.

The main body 10 is made of a cylinder having a cylindrical mixing chamber 11 having an opened upper surface and a disk-shaped lid 12 for opening and closing the upper end of the mixing chamber 11 is provided at an upper end.

The mixing unit 11 mixes and mixes water and cement introduced into the mixing chamber 11 and mixes a plurality of (in this embodiment, two) mixing units 11 rotatably installed in the mixing chamber 11, And a stirring motor 22 connected to the stirring and stirring screw 21 on the outside of the main body 10 to transmit rotational force to the shaft of the stirring and stirring screw 21.

The stirring motor 22 is installed at the upper end of the motor mount block 24 installed at one side of the main body 10 and is operated by electric energy applied to the outside. The rotary shaft 23 of the two stirring and stirring screws 21 passes through the center of the lid 12 and is connected to the shaft of the stirring motor 22 and rotates by receiving the rotational force.

Wherein the filter unit comprises a plurality of sieving screens 30 for filtering and aggregating the agglomerated particles in a mixture of cement and water flowing in the mixing chamber 11 by the stirring unit, And a support member (31) which is supported in an upright position within the support member.

The plurality of sieving screens 30 are arranged at a predetermined distance from the center of the mixing chamber 11 at a predetermined distance in the radial direction and are made of a rectangular mesh having a predetermined eye size, It filters out. The mesh sizes of the plurality of sieving screens 30 may be all the same or may be arranged so as to become smaller from the upstream side to the downstream side with respect to the flow direction of the mixture of cement and water. For example, when the stirring / stirring screw 21 rotates counterclockwise in FIG. 3, the mixture of cement and water also flows counterclockwise in the mixing chamber 11. Therefore, in this case, if the eye size of each of the screening screens 30 is set to be smaller in the counterclockwise direction of the mixing chamber 11, the screening screen 30 is hung up sequentially from the larger mixture.

The support member 31 is installed on the inner wall surface of the mixing chamber 11 so as to extend in the vertical direction to support the sieve 30. The support member 31 includes two support plates 32 which are curved surfaces having a curvature corresponding to the curvature of the mixing chamber 11 and are arranged in parallel with each other and a support plate 32 provided on the inner surface of the support plate 32, The fixed frame 33 has a rectangular shape. The rim 30 has a rim connected to the stationary frame 33 by a fastening means such as a screw.

In this embodiment, the filtering net 30 is fixed to the fixing frame 33 of the support member 31 with screws or the like, but in order to facilitate the replacement and maintenance of the filtering net 30, A plurality of 'c' shaped rail-shaped slots 34 are formed on the inner side of the support plate 32 of the support member 31 so as to oppose the sieve 34 to easily fit the sieve 30 through the upper end of the slot 34 It may be possible to separate it.

The mixture particles of cement and water caught in the sieve 30 are decomposed by the vibration unit which vibrates the sieve 30, and are made into fine particles. The vibrating unit may be composed of a vibrator that is directly connected to the upper end of the filtering net 30 at the upper end of the mixing chamber 11 to vibrate the filtering net 30. In this case, It may cause malfunction or failure.

3 and 4, the vibrator 41 is provided outside the main body 10, and the vibrator 41 and the upper end of the sieve 30 are connected to each other through the vibration transmitting member 42 It is preferable to transmit the oscillation of the vibrator 41 to the sieve 30.

The vibrator 41 is installed in an arcuate vibrator mounting plate 43 provided outside the upper end of the main body 10. [ The vibrator 41 may be constructed by applying a well-known ultrasonic vibrator such as a nickel vibrator, a ferrite vibrator, a piezoelectric ceramic vibrator, a B.L.T vibrator, a quartz crystal vibrator, etc. to generate ultrasonic vibrations.

The vibration transmitting member 42 may be formed of a long and thin metal plate having one end connected to the vibrator 41 and vibrating and the other end connected to the upper end of the filtering net 30. [

In this embodiment, four filter screens 30 are provided in the filter unit, two vibrators 41 are provided on the vibrator mounting plate 43, two vibration transmitting members 42 Are connected to ultrasonically vibrate each of the sieving screens 30.

The grout mixing apparatus of the present invention configured as above operates as follows.

The lid 12 of the main body 10 is opened and cement and water are put into the mixing chamber 11 at a predetermined mixing ratio and the lid 12 is closed to close the inside of the mixing chamber 11. [

Then, when power is applied to the stirring motor 22 and the stirring and stirring screw 21 is rotated in one direction, a mixture of cement and water is mixed with the stirring screw 21 while flowing. The mixture of the cement and water flowing by the stirring screw 21 passes through the filter net 30 of the filter unit while the particles are finely crushed so that the particles larger than the eyes of the sieve 30 And is caught by the filter net 30.

At this time, when an external power source is supplied to the vibrator 41, the vibration of the vibrator 41 is transmitted to the sieve 30 through the vibration transmitting member 42 so that the sieve 30 is ultrasonically vibrated. As a result, the particles caught in the sieve 30 are decomposed into fine particles and passed through the sieve 30.

In the mixing chamber 11, the stirring screw 21 rotates to mix the cement and the water. The mixture of the cement and the water is crushed while passing through the sieve 30, and the sieve 30 is ultrasonically vibrated The particle size of the grout can be reduced because the particles of the mixture of cement and water caught in the sieve 30 are decomposed into fine particles.

It is preferable that the frequency of the vibrator 41 is proportional to the number of revolutions of the stirring motor 22 when the vibrator 41 vibrates the screen 30. That is, if the flow rate of the mixture of cement and water is increased by increasing the number of revolutions of the agitation motor 22, it is preferable to increase the frequency of the particle degradation in the sieve 30 by increasing the frequency of the vibrator 41.

8 and 9, in the course of rotating the stirring screw 21 to flow a mixture of cement and water and filtering out mixture particles of agglomerated cement and water through the sieve 30 of the filter unit, A flow auxiliary unit 50 may be additionally installed at one side of the filter unit in the mixing chamber 11 so as to suck up the particles caught in the sieve 30 by a high pressure to prevent the sieve 30 from being clogged have.

The flow assist unit (50) is installed on the downstream side of the filter unit based on the flow direction of the mixture of cement and water to generate a suction force. In this embodiment, the flow assist unit 50 includes a flow guide 51 formed of a tubular body that is open at both ends thereof, and a flow guide 51 which is rotated by a motor 53 inside the flow guide 51 to mix a mixture of cement and water And an impeller 52 for forced flow.

When the impeller 52 is rotated by its own motor 53, the water is sucked inward through the one end of the flow guide 51 through the impeller 52, and then, through the other end of the flow guide 51, The particles trapped in the sieve 30 are decomposed by the vibration of the sieve 30 and sucked by the flow assist unit 50 so that the sieve 30 can be prevented from being clogged by the agglomerated particles have.

In order to verify the performance of the grouting apparatus according to the present invention, experiments were conducted to manufacture grout under the following conditions.

The temperature of the laboratory was maintained at 20 ℃ and the relative humidity was 40% ~ 60% in order to eliminate the uncertainty due to laboratory conditions. The stirring speed of the stirring screw (21) was maintained at 600 rpm at low speed and 1100 rpm at high speed, and stirring time was kept constant for 3 minutes. The water cement ratio was 100%. The cement used was ordinary Portland cement (OPC), slag cement and micro cement powder of 6000 which were suitable for KS standard.

The parameters of each experiment were bleeding, viscosity, drop time, uniaxial compressive strength, particle size analysis, XRD and optical microscope. The bleeding rate was measured in accordance with KS F 2433 " Test method for bleeding rate and expansion rate of injected mortar ". The blending ratio was measured at intervals of 60 minutes by adding the mixed solution to a 1000 ml measuring cylinder, and after 180 minutes, the bleeding rates were compared. The viscosity was measured at 2 rpm using a LVDV-Ⅱ viscometer manufactured by American B Co., Ltd. at 100 rpm. For the determination of the flow time, the test for the fluidity of the grout was carried out by measuring the time and the flow of the grout according to KS F 2432 "Concrete test method of injected mortar". Uniaxial compressive strength was measured by the method of KS F 2314 "Unconfined compression test of soil". The specimens for the measurement of compressive strength were prepared using 5 × 5 × 5 ㎝ molds, air cured in molds until 3 days, and cured in water after 3 days. The uniaxial compressive strength test was carried out at 3 days, 7 days, and 28 days, and the compressive strength test was carried out at a rate of 1.0 mm / min. In the uniaxial compression test, gelation reaction was generated within 10 seconds by using CSA-based grade settlement to prevent the volume change due to the bleeding phenomenon.

The amount of bleeding was measured for each cement and the bleeding rates were compared after 180 minutes. As can be seen in Table 1 below, it can be seen that the bleeding rate in the test passed through the screen 30 is reduced. In the case of micro cement, it was confirmed that the bleeding hardly occurs even after 180 minutes. This is because the size of the cement particles is small and the area of contact with water is the largest, so it solidifies faster than other samples. In the case of slag cement, the bleeding rate decreased 2.2% when passing through the sieve net 30, and that of ordinary portland cement decreased 3.6% and 2.4%, respectively. The bleeding rate decreased by 5.4% and 4.2% depending on the difference in stirring speed, and it was confirmed that the stirring speed affects the bleeding rate.

As a result of viscosity measurement, micro cement showed the highest value of 198 cPs, and it was confirmed that viscosity decreased in the order of slag cement, high speed general portland cement and low speed general portland cement. This is because the shear resistance decreases with the rotation of the viscometer as the particle size is evenly distributed.

The results of the submerged test were similar to those of the viscosity test. This is because the friction between the submerged test apparatus and the suspension has a great influence on the submerged time.

Name of sample Stirring speed
(rpm) Presence or absence of the filter Bleeding rate (%) Viscosity (cPs) Fall Time
(sec)
General Portland Cement


1100 Passing oil 21.8 61 8.8 Pass through 25.4 56 9.1 600
Passing oil 27.2 55 9.2 Pass through 29.6 52 9.4 Slag cement
600
Passing oil 15.6 84 8.7 Pass through 17.8 78 8.9 Micro Cement (8000) 600 Pass through 0.8 198 7.3

Uniaxial compressive strength tests were performed on the 3rd, 7th and 28th days. As shown in Table 2, micro cement was 5 times larger at 3 days strength than other samples. This is because the microcement particles are thin and have a larger contact area with water than other materials. It was confirmed that the strength of 7 days passed through the vortex shed was 5.5 ~ 7.9% larger than that of the paints and samples. This can be attributed to the fact that the contact area of the agglomerated particles separated by the particles was relatively improved while talking on the vibration screen.

Name of sample
Stirring speed
(rpm) Presence or absence of the filter Uniaxial Compressive Strength (MPa) 3 days 7 days 28th
General Portland Cement

1100 Passing oil 2.7 20.1 44.1 Pass through 2.6 19.0 42.2 600
Passing oil 1.8 16.3 34.6 Pass through 1.4 15.4 33.7 Slag cement
600
Passing oil 1.8 17.5 38.1 Pass through 1.6 16.2 37.0 Micro Cement (8000) 600 Pass through 10.6 31.4 46.7

The particle size analysis was carried out wet, and the agitation speed of ordinary portland cement was 600 rpm. 10A is a graph showing the result of particle size analysis for a sample which has passed through the vibration diverting net 30 of the present invention and FIG. ). The average particle size of the sample passed through the screen 30 of the present invention was 21.2 μm, and the average particle size of the sample not passing through the screen 30 was 22.8 μm Respectively. The 10% passing particle size of the sample passed through the vibration screen 30 was 6.3 탆, the 50% passing particle size was 15.7 탆, and the 90% passing particle size was 42.4 탆. The 10% passing particle size of the sample which did not pass through the vibration screen was 6.8 탆, the 50% passing particle size was 16.9 탆, and the 90% passing particle size was 46.4 탆.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined by the appended claims. And it is to be understood that such modified embodiments belong to the scope of protection of the present invention defined by the appended claims.

10: main body 11: mixing chamber
12: cover 21: stirring screw
22: Stirring motor 23:
30: Filter wire 31: Support member
32: support plate 33: fixed frame
34: Slot 41: Oscillator
42: vibration transmitting member 40: flow auxiliary unit
51: flow guide 52: impeller

Claims (11)

A main body 10 having a mixing chamber 11 into which cement and water are mixed and mixed;
An agitation unit for agitating the cement and water introduced into the mixing chamber 11;
A filter unit (30) having a sieve (30) through which a mixture of cement and water is continuously passed through the mixing chamber (11) mixed by the stirring unit;
A vibrating unit for vibrating the screen (30);
/ RTI >
The filter unit comprises a support member 31 provided on the inner wall surface of the mixing chamber 11 so as to extend in the vertical direction and spaced apart from the support member 31 along the flow direction of the mixture of cement and water And a plurality of sieving screens (30). The stirring device according to claim 1, wherein the stirring unit comprises: a stirring screw (21) rotatably installed in the mixing chamber (11); and an agitating screw And a stirring motor (22) for transmitting a rotational force to the shaft of the grouting motor (21). delete 2. A grout mixing apparatus according to claim 1, characterized in that the sizes of the eyes of the respective drawing screens (30) are different. The grout mixing apparatus according to claim 4, wherein the sizes of the eyes of the plurality of sieving screens (30) are arranged so as to become smaller from the upstream side to the downstream side with respect to the flow direction of the mixture of cement and water. The grouting device according to claim 1, wherein the support member (31) is formed with a plurality of slots (34) guided and supported while both side ends of the sieve net (30) are inserted and extended in the vertical direction. The grouting device according to claim 1, wherein the vibration unit is a vibrator (41) installed at an upper end of the sieve (30). The vibrating unit according to claim 1, wherein the vibrating unit comprises: a vibrator (41) provided outside the main body (10); a vibrator having one end connected to the vibrator (41) And a vibration transmitting member (42) for transmitting the vibration of the grout (30) to the screen (30). [6] The apparatus according to claim 1, further comprising a flow auxiliary unit installed at one side of the filter unit inside the mixing chamber (11) to pump a mixture of cement and water that has passed through the filter unit and pump it in the flow direction Grout mixing device. The flow assistant unit according to claim 9, wherein the flow assist unit comprises: a flow guide (51) having a tubular body formed with both ends open; And an impeller (52) for flowing the grout (52). The grouting device according to claim 2, wherein a rotational speed of the stirring motor (22) and a frequency of the vibration unit are proportional to each other.

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