JPH09228640A - Removing method of residual concrete in concrete force conveying pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the clogging of residual concrete, and carry out quick post-treatment when residual concrete in a concrete force conveying pipe is removed. SOLUTION: A series superposing body 10 inserted into a concrete conveying pipe 5 is moved at the pressure P of high-pressure water W poured at the rear of the sealing body 17 of the superposing body 10, and compressed by the resistance of residual concrete 3' in front of the superposing body 10, and the outer circumferences of clay lumps 12, 14, 16 interposed among sponge 11, 13 and sealing bodies 15, 17 in the series superposing body 10 are connected closely onto a pipe inner wall by plastic deformation, and the clay lumps 12, 14, 16 are deformed plastically in the diameter-expanding direction at all times so as to supply abrasion by sliding with the pipe inner wall. The series superposing body 10 is moved in the concrete force conveying pipe 5 at a pressure P while maintaining the excellent cut-off state, and pushes out residual concrete 3'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, in the field of construction and civil engineering construction, uses concrete pump trucks to drive concrete to a desired location by means of concrete pumping pipes, and then to remove the raw concrete remaining in the concrete pumping pipes. It concerns the method of removal.

[0002]

2. Description of the Related Art In the case of placing concrete in construction or civil engineering work, a concrete pump truck is placed in a predetermined place, and a concrete pumping pipe is placed from there to a concrete placing place. The supplied ready-mixed concrete is pressure-fed to the pouring place via the concrete pressure-feeding pump of the concrete pump truck and the concrete pressure-feeding pipe, and is placed. After the concrete pouring work is completed, it is necessary to immediately remove the fresh concrete remaining in the concrete pumping pipe. In the removal work, a method as shown in FIG. 6 has been conventionally used.

That is, first of all, the concrete pressure pipe 101 used for placing concrete has a diameter of 10 mm.
1. A spherical sponge 102 larger than the inner diameter of 1, a cylindrical sponge 103, and a bellows-shaped sealing body 104, 105 made of an elastomer (rubber-like elastic body) are sequentially inserted in series with each other, and high-pressure water W is injected from behind. By doing so, the sponges 102 and 103 in the pressure feed pipe 101 and the sealing body 10
4, 105 are moved and residual concrete 106 is pushed out and discharged. In the figure, the spherical sponge 102 and the columnar sponge 103 indicate the pressure P of the high-pressure water W.
It is shown deformed by.

[0004]

PROBLEM TO BE SOLVED BY THE INVENTION Concrete pumping pipe 1
In the pouring of ready-mixed concrete using 01, since the pressure feed pipe 101 is added and extended as the pouring position of the concrete gradually changes, the extended length is, for example, a shield. Depending on the type of work, such as placing secondary wrapping concrete for lining in tunnel construction, it can reach several hundred meters. And
Needless to say, the volume of the residual concrete 106 filled in the concrete pressure-feed pipe 101 is proportional to the length of the pressure-feed pipe 101.
In order to drain the residual concrete 106 in 01 by the conventional method, the water injection pressure must be extremely high.

When the concrete feed pipe 101 is relatively short, the sealing bodies 104, 105 and the sponges 102, 103 in front of the sealing bodies 104, 105 by the pressure P of the high-pressure water W to be poured.
The moving force of the residual concrete 106 on the front surface of the sponge 102 is sufficiently larger than the pressing force of the sealing bodies 104, 105 and the sponges 102, 103 against the inner surface of the concrete pumping pipe 101 and the frictional resistance due to the viscosity of the residual concrete 106. Is smoothly pushed out and discharged.
However, when the concrete pressure pipe 101 is long, the water injection pressure must be increased correspondingly,
As shown in FIG. 7, the amount of water leaked forward from between the inner surface of the concrete pumping pipe 101 and the outer peripheral surfaces of the sealing bodies 104 and 105 and the sponges 102 and 103 is increased, whereby residual concrete on the front surface of the sponge 102 is increased. Since a part of 106 is diluted by flooding and its cement component is washed away, gravel and sand 106a in the concrete 106 are separated. In such a state, fluidization of the residual concrete 106 is impaired, and the gravel or sand 10
Since a large frictional force is applied between the pipe 6a and the inner surface of the pipe, the resulting resistance may exceed the pumping capacity of the pump car that supplies the high-pressure water W, and the pumping may become impossible.
Although it takes some time to restore the concrete, when the high-strength concrete that gives strength in a short time is placed, the concrete pressure-feeding pipe can be restored after only about 1 hour has passed for the restoration work. The residual concrete 106 inside 101 may harden, and the entire concrete pressure pipe 101 may become unusable.

The present invention has been made under the circumstances as described above, and its technical problem is to remove the fresh concrete remaining in the concrete feed pipe after the concrete is placed by extrusion. The purpose of the present invention is to prevent clogging of residual concrete in the concrete pumping pipe, to smoothly discharge this residual concrete, and to enable quick post-treatment.

[0007]

The above-mentioned technical problems are as follows.
This can be effectively solved by the present invention. That is, the method for removing the residual concrete in the concrete pumping pipe according to the present invention is, after the concrete pouring using the concrete pumping pipe is completed, in the concrete pumping pipe in which the concrete remains inside, a required number of pressing members and required members from one end A number of sealing bodies are sequentially inserted with a clay lump having plasticity interposed therebetween, and a series multilayer body composed of these pressing members, sealing bodies and clay lumps is provided from one end of the concrete pressure-feeding pipe. The pressure of the high-pressure water to be poured causes the concrete to be moved to the other end of the pressure pipe to push out the residual concrete in front of the pressing member. In this case, for example, bentonite containing clay and / or montmorillonite as a main component is preferably used as the clay mass.

In the serial multi-layer body inserted in the concrete pumping pipe, the sealing body is inserted into the inner wall of the concrete pumping pipe in a substantially close contact state, and the moving force due to the pressure of the high-pressure water received behind the sealing body is applied to the front pressing member. The clay mass interspersed with this in-situ multi-layered body is plastically deformed so as to be expanded in the radial direction by receiving a compressive force in the moving direction (the length direction of the concrete pumping pipe). The outer periphery of the pipe tightly contacts the inner wall of the pipe to reliably stop the high pressure water.

That is, the series laminated body moves due to the pressure of the high-pressure water that is poured behind the sealed body, but the residual concrete in front of the series resists the movement, so that the series laminated body is constructed. The respective sealing bodies, pressing members and clay blocks to be compressed are compressed in the arrangement direction (moving direction). Particularly, since the outer peripheral surface of the lump of clay is in close contact with the inner wall of the pipe well due to the plastic deformation, a good water blocking effect is exhibited. Moreover, since this clay lump is constantly subjected to the radial expansion deformation due to the compressive force so as to compensate for the wear caused by the sliding with the inner wall of the pipe, the in-line multilayer body maintains the good water-stopping state while maintaining the good water-stopping state. Due to the pressure, it moves in the concrete pumping pipe, and the separation of the gravel and the like due to the dilution of the residual concrete in the pipe existing on the front surface in the moving direction and the increase in frictional resistance due to this are prevented. In addition, even if the supplied high-pressure water slightly leaks forward in the moving direction of the series multilayer body,
Since some of the clay blocks are mixed during the leakage process, the dilution of residual concrete is effectively suppressed.

In particular, a clay lump composed of clay and bentonite containing montmorillonite as a main component is excellent in plasticity and water stopping property, and the water absorption improves the lubricity of the inner surface of the concrete pumping pipe. In addition, the residual concrete can be extruded and discharged smoothly.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A method for removing residual concrete in a concrete pumping pipe according to the present invention is preferably applied to a work for removing residual concrete in a concrete pumping pipe used for placing secondary wound concrete in shield construction. One embodiment will be described with reference to FIGS. 1 to 5.

First, FIG. 1 shows a state of placing secondary-rolled concrete in a shield construction. Reference numeral 1 is a shield machine for excavating a shield tunnel, and 2 is a primary cover assembled on the excavated inner wall. Industrial segment,
Reference numeral 3 is a secondary winding concrete placed on the inner circumference of the segment 2. That is, in constructing a shield tunnel, first, the starting shaft B of a predetermined depth from the ground A
And, a reaching side shaft (not shown) is constructed, the shield excavator 1 excavates the underground from the starting side shaft B to the reaching side shaft, and the segment 2 is assembled on the inner wall of the tunnel at the rear part of the shield machine 1. A primary lining is applied, a cylindrical form 4 is assembled on the inner periphery of the primary lining, and a secondary wound concrete 3 is cast. The secondary winding concrete 3 is placed by placing the cylindrical formwork 4 from the ground through the shaft B and the tunnel shaft C.
The concrete pumping pipe 5 is arranged up to the placing space by the above, and the concrete pump truck 6 placed on the ground A pumps the fresh concrete supplied from the concrete mixer truck 7 into the placing space through the concrete feeding pipe 5. It is done by filling.

When the casting of the secondary-rolled concrete 3 is completed, the total length of the concrete-conveying pipe 5 is
If concrete that has not reached the casting space remains, and this residual concrete hardens in the pipe, the concrete pumping pipe 5 cannot be reused and must be removed promptly. Therefore, in the method of removing residual concrete according to the present invention, first, the connection between the ground-side end 5a of the concrete pumping pipe 5 and the concrete discharge port of the concrete pump car 6 is released, and the end 5a is
As shown in FIG. 2, a spherical sponge 11 having a diameter larger than the inner diameter of the concrete pumping pipe 5 as the leading pressing member, a first clay mass 12 having an appropriate size having plasticity, and a second pressing member. As a cylindrical sponge 13 having a diameter larger than the inner diameter of the concrete pumping pipe 5, a second clay mass 14 similar to the first clay mass 12, and a sealing body 15 made of an elastomer molded in a bellows shape. Then, a third clay mass 16 similar to the first clay mass 12 and a second sealing mass 17 similar to the first sealing mass 15 were sequentially inserted, and as shown in FIG. Thus, the in-line multilayer body 10 for extruding the residual concrete 3'is configured. The clay blocks 12, 14, 16 are made of clay or bentonite to which an appropriate amount of water is added to impart plasticity.

After the insertion of the series multilayer body 10 is completed, the process shown in FIG.
As shown in, the end 5 on the ground side of the concrete pumping pipe 5
A is connected to the discharge port of the pressurized water supply pump 8a of the pump car 8 via the pressure resistant water hose 8b, and pressurized water injection of the high pressure water W is started. In-line multi-layer body 1 in concrete pumping pipe 5
0 receives the pressure P of the high-pressure water W continuously injected into the pipe inner space behind the bellows-shaped second sealing body 17 at the tail end thereof, but the front surface of the spherical sponge 11 at the top is made of concrete. Since there is residual concrete 3 ′ that extends to the end on the C side of the tunnel mine of the pumping pipe 5, the series multilayer body 1
0 is compressed between the residual concrete 3 ′ and the high-pressure water W. That is, as shown in FIG.
Of the sponges 11 and 13, the sealing bodies 15 and 17 and the clay blocks 12, 14 and 16 interposed therebetween are high-pressure water W.
As the pressure P rises, it is compressed, and when the pressure P exceeds a predetermined high pressure value, the residual concrete 3 '
The extrusion movement for is started. As shown in FIG. 4, the residual concrete 3 ′ pushed out is gradually discharged from the end portion 5 b of the concrete pumping pipe 5 on the C side inside the tunnel.

As shown in FIG. 5, in the compressed state of the series laminated body 10 by the pressure P of the high-pressure water W, in particular, the clay blocks 12, 14 and 16 are plastically deformed in the radial direction,
The outer periphery thereof is brought into close contact with the inner wall of the concrete pressure-feeding pipe 5, and the water that has entered this close contact portion is absorbed to be lubricated and exhibit good water-stopping performance. Therefore, it is possible to effectively prevent the high-pressure water W behind the in-line multilayer body 10 from leaking to the residual concrete 3 ′ side. Further, even if a slight leak occurs, the leaked water becomes a muddy when passing through the outer circumferences of the clay blocks 12, 14 and 16. Therefore, by diluting the residual concrete 3 ′ in front of the spherical sponge 11 at the front. The separation of the gravel or sand is effectively prevented. Also, each clay block 12,1
The outer peripheral portions of 4, 16 gradually wear due to sliding with the inner wall of the pipe, but the plastic deformation due to the pressure P always acts in the radial expansion direction so as to complement this wear, so there is no decrease in radius due to wear. Therefore, good water stopping performance is always maintained.

As described above, each clay mass 12, 14, 16
Is gradually decreased due to wear and the like accompanying movement, and therefore the initial amount of injection is appropriately determined in consideration of the inner diameter and length of the concrete pumping pipe 5, the fluidity of the residual concrete 3 ′, and the like. Other spherical sponge 11, cylindrical sponge 1
Although the third and first and second sealing bodies 15 and 17 are slightly worn, they withstand repeated use considerably, and therefore, they may be replaced in a timely manner in consideration of the state of wear.

The present invention is not construed as being limited to the illustrated embodiment. For example, in the above embodiment, the removal work of the residual concrete in the concrete pumping pipe used for the placement of the secondary rolled concrete in the shield construction has been described, but the present invention is also applicable to other various concrete placements. It can be applied to remove the residual concrete in the concrete pumping pipe after completion. Also, the sponge 1 as a pressing member
The shapes of 1 and 13 and the sealing bodies 15 and 17 are not particularly limited, and the number thereof and the number of clay lumps are also appropriately determined according to the use conditions.

[0018]

EXAMPLE A concrete pumping pipe 5 having a pipe diameter of 125 mm and a total length of 500 m was kneaded by adding an appropriate amount of water to bentonite mainly composed of montmorillonite as clay lumps 12, 14 and 16 to be interposed in the series laminated body 10. 1
The work by the above-mentioned process was performed using 0 liter. As a result, the residual concrete 3'in the pipe was completely discharged without being clogged on the way, and the volume of the clay blocks 12, 14, 16 in the series multi-layered body 10 subsequently discharged was reduced due to wear. When this was collected and weighed, about half (about 5 liters) remained.

[0019]

EFFECTS OF THE INVENTION According to the method for removing the residual concrete in the concrete feed pipe according to the present invention, when the residual concrete in the concrete feed pipe is extruded and removed by the pressure of high-pressure water, the residual concrete in the concrete feed pipe is removed. The intervening clay mass is plastically deformed, and its outer peripheral surface comes into close contact with the inner surface of the pipe to ensure good water stopping.Therefore, leakage water separates the sand and gravel of the residual concrete, increasing extrusion resistance. It can be prevented and residual concrete can be discharged quickly. Moreover, since the clay lump is extremely inexpensive, it is possible to prevent an increase in cost due to restoration work due to clogging of residual concrete on the way, replacement of the concrete pressure pipe, and the like.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a pouring situation of secondary rolled concrete in shield construction.

FIG. 2 is an explanatory diagram of an in-line multilayer body insertion process showing an embodiment in which the present invention is applied to a work of removing residual concrete in a concrete pumping pipe used for placing the secondary rolled concrete.

FIG. 3 is an explanatory diagram showing an inserted state of the series multilayer body in the above embodiment.

FIG. 4 is an explanatory view showing a situation in which high-pressure water is pressurized and injected by a pressure water pump of a pump car from behind the in-line multilayer body in the above embodiment.

FIG. 5 is an explanatory diagram showing a state in which the in-line multilayer body in the pipe is compressed by the pressure of high-pressure water in the above embodiment.

FIG. 6 is an explanatory view showing a method for removing residual concrete in a concrete pressure-feeding pipe according to a conventional technique.

FIG. 7 is an explanatory view showing a situation in which residual concrete is diluted and separated by leakage water from the outer periphery of the in-line multilayer body in the above-mentioned conventional technique.

[Explanation of symbols]

 3'residual concrete 5 concrete pumping pipe 10 in-series multi-layer body 11,13 sponge (pressing member) 15,17 sealing body 12,14,16 clay lump W high pressure water

Claims (2)

[Claims] 1. After the completion of the concrete pouring using the concrete pressure-feeding pipe, a required number of pressing members and a required number of sealing bodies are provided between one end of the concrete pressure-feeding pipe in which concrete remains. Sequentially inserting with a clay lump having plasticity interposed, a series multi-layered body consisting of these pressing member, sealing body and clay lump is fed by the pressure of high-pressure water injected from one end of the concrete feed pipe to the concrete A method for removing residual concrete in a concrete pumping pipe, characterized in that the residual concrete in front of the pressing member is extruded by moving it to the other end side of the pipe. 2. The method for removing residual concrete in a concrete pumping pipe according to claim 1, wherein bentonite containing clay and / or montmorillonite as a main component is used as the clay mass.