JP2014084568A - Concrete placing system and concrete placing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete placing system capable of placing high quality concrete even when a conveyance route has vertically long piping.SOLUTION: A concrete placing system to place concrete at a site having a difference in height comprises: a hopper 2 installed on a high place; vertical piping 3 downwardly extended from a discharge port 22 of the hopper 2; a concrete pump 4 connected to a downstream side of the vertical piping; and a discharge pipe 5 enabling the concrete conveyed by the concrete pump 4 to be supplied to a placing position. The hopper has a sensor section to detect a remaining amount of the input concrete. The sensor section transmits a signal to the concrete pump.

Description

  The present invention relates to a concrete placement system and a concrete placement method for placing concrete in a place with a height difference such as from the ground to the ground.

  Concrete is usually transported from the ground in order to construct bottom plates and side walls of underground structures such as shafts and underground tanks. Here, when the underground structure is located at a large depth in the ground, the vertical transport distance becomes long, and thus various problems occur depending on the transport method.

  For example, when concrete is dropped freely over a long distance, the material may be separated into aggregate and moisture during the fall or collision. When material separation occurs, coarse aggregate tends to accumulate at the bottom of the vertical pipe, and the pipe may become clogged, making it impossible to continue the subsequent concrete placement. Therefore, various developments have been made to solve these problems (see Patent Documents 1-3).

  Patent Document 1 discloses a concrete beating that can balance the prevention of material separation and the securing of work efficiency by providing valves for adjusting the flow speed (falling speed) of concrete at a plurality of locations in a vertical pipe. An installation device is disclosed.

  Further, in Patent Document 2, an outer pipe that is slidable in the vertical direction is attached to the lower end of the vertical pipe and is placed in the outer pipe, so that material separation is possible even when high-viscosity concrete with high viscosity is used. A placement method that prevents the occurrence of the problem is disclosed.

  On the other hand, in Patent Document 3, a branch pipe is provided in the middle of a vertical pipe so that concrete can be placed from a plurality of heights, and even when there is a height difference exceeding 100 m, it is carried out efficiently. A possible concrete placement method is disclosed.

JP 2001-207449 A JP-A-9-137606 JP 2004-1000026 A

  However, in the configuration of Patent Documents 1-3, since the force for transporting concrete from the ground hopper to the ground placement site is due to free fall based on gravity, material separation occurs to some extent. . When the material separation occurs, as described above, the vertical pipe is clogged and the quality of the concrete is deteriorated.

  On the other hand, when the remaining amount of the hopper on the ground decreases, the flow of the concrete into the vertical pipe becomes intermittent, and air may be caught between the concrete thrown in later and the concrete transported earlier. And when concrete containing such air is poured as it is, there is a possibility that it becomes a low-quality concrete structure.

  Accordingly, an object of the present invention is to provide a concrete placement system and a concrete placement method capable of placing high-quality concrete even when a long vertical pipe is interposed in the transport path.

  In order to achieve the above object, a concrete placement system according to the present invention is a concrete placement system for placing concrete in a place with a height difference, and includes a hopper installed above, and a discharge of the hopper. A vertical pipe extending downward from the outlet; a concrete pump connected to the downstream side of the vertical pipe; and a discharge pipe for supplying the concrete carried out by the concrete pump to a placement site, the hopper A sensor unit for detecting the remaining amount of the input concrete is provided, and a signal is transmitted from the sensor unit to the concrete pump.

  Here, the sensor unit may be configured to transmit a signal for stopping the concrete pump when the height of the concrete upper surface in the hopper becomes equal to or lower than a predetermined level.

  The concrete placement method of the present invention is a concrete placement method using the above concrete placement system, and the step of installing the concrete placement system and filling the vertical pipe with a cement-based solidifying material. And a step of feeding concrete into the hopper, a step of operating the concrete pump, and a step of supplying the concrete toward the placement site of the discharge pipe.

  In the concrete placing system of the present invention configured as described above, an upper hopper and a lower concrete pump are connected by a vertical pipe. The hopper is provided with a sensor unit, and the concrete pump is controlled by a signal transmitted from the sensor unit.

  By connecting the concrete pump to the downstream side of the vertical pipe in this way, the concrete is continuously conveyed in the vertical pipe based on the suction force of the pump, so that material separation can be made difficult to occur. . If material separation does not occur, the workability and quality of the concrete can be maintained, and the risk of clogging the vertical piping is reduced.

  Then, the state where the remaining amount of the hopper becomes below a predetermined value is detected by the sensor unit, and the control is made such that the concrete pump is automatically stopped by the detection signal, so that the entrainment of air is prevented. You will be able to cast high quality concrete.

  In the concrete placing method of the present invention, the vertical pipe is filled with a cement-based solidifying material such as mortar, and then concrete is poured into the hopper and the concrete pump is operated.

  For this reason, even if it is the concrete thrown in at the beginning of construction, it does not fall freely in the vertical pipe and material separation does not occur, so that all concrete can be placed with high quality.

It is a longitudinal cross-sectional view for demonstrating the structure of the concrete placement system of embodiment of this invention. It is a top view for demonstrating the structure of a concrete placement system. It is a perspective view explaining the structure of a hopper and a sensor part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 are explanatory views showing the configuration of the concrete placing system of the present embodiment.

  In the present embodiment, as shown in FIG. 1, a case where a concrete structure such as a bottom slab or a side wall 10 is constructed in a vertical shaft 1 dug down from the ground G in the vertical direction will be described as an example. That is, the side wall 10 is a reinforced concrete structure formed in a cylindrical shape with a predetermined thickness from the pit wall 1a of the shaft 1 as shown in FIGS.

  Since this side wall 10 is raised from the bottom plate of the vertical shaft 1, when constructing the deep vertical shaft 1, the difference in height between the ground G into which the concrete is poured and the placement site becomes very large.

  In the present embodiment, a disc-shaped moving stage 11 that is sequentially moved from the bottom to the top inside the shaft 1 is disposed, and concrete is discharged from the moving stage 11 toward the placement site. Will be described.

  As shown in FIG. 1, a scaffold 12 is provided on the outer peripheral edge of the moving stage 11 in a ring shape along the inner side of the position that becomes the inner peripheral surface of the side wall 10. The moving stage 11 is supported by the support members 13 attached from the scaffold 12 toward the pit wall 1a, and is raised in accordance with the raised height of the side wall 10. One process for raising the moving stage 11 is referred to as a driving lift.

  The concrete placement system according to the present embodiment includes a hopper 2 installed on the ground G, a vertical pipe 3 extending downward from a discharge port 22 of the hopper 2, and a concrete pump connected to the downstream side of the vertical pipe 3 4 and a discharge pipe 5 for supplying the concrete carried out by the concrete pump 4 to the placement site.

  The hopper 2 is formed in a funnel shape that tapers from the upper inlet 21 toward the lower outlet 22 as shown in FIG. 3. Concrete that has been transported by a concrete mixer truck or the like is thrown toward the inlet 21.

  The hopper 2 is provided with a discharge port 22 on the lower surface, and a vertical pipe 3 is connected directly below the discharge port 22. In FIG. 1, the position of the pipe main body that extends straight downward from the position of the vertical pipe 3 relative to the position of the discharge port 22 of the hopper 2 is shifted to the center side of the shaft 1, so the upper part 3 a of the vertical pipe 3 is slightly inclined. It has become.

  The vertical pipe 3 can be formed to a desired length by adding a steel pipe or the like. The vertical pipe 3 is provided with a valve 31 as necessary. In FIG. 1, the height difference between the ground G and the moving stage 11 is substantially the length of the vertical pipe 3.

  A horizontal pipe 41 connects between the lower end 3 b of the vertical pipe 3 and the concrete pump 4. The horizontal pipe 41 can also be formed to a desired length by adding a steel pipe or the like. Further, the horizontal pipe 41 is provided with a valve 41a as necessary.

  In the present embodiment, as shown in FIG. 2, the horizontal pipe 41 is laid on the moving stage 11 so as to have a U shape in plan view. This horizontal pipe 41 is arranged on the upstream side of the concrete pump 4.

  The concrete pump 4 installed on the moving stage 11 is a pressure feed pump using an electric motor as a power source. The pressure feed pump is configured to push the concrete flowing in from the upstream side to the downstream side by a reciprocating hydraulic piston.

  A branch pipe 42 is connected to the downstream side of the concrete pump 4 as shown in FIG. Since this branch pipe 42 is laid in the horizontal direction on the moving stage 11, it can be said that it is a horizontal pipe.

  The branch pipe 42 is configured such that one main pipe 42a connected to the concrete pump 4 is divided into two branch pipes 42b and 42b. The two branch pipes 42b and 42b are extended in directions different by 180 degrees.

  Then, discharge pipes 5 and 5 such as flexible hoses are connected to the respective ends of the branch pipes 42b and 42b. The distal ends of the discharge pipes 5 and 5 are arranged at a planned construction position of the side wall 10 which is a place where concrete is placed.

  As shown in FIG. 3, a level sensor 6 as a sensor unit is attached to the hopper 2 of the present embodiment. This level sensor 6 is a detection device for detecting the remaining amount of concrete thrown into the hopper 2.

  The level sensor 6 is connected to a control unit (not shown) of the concrete pump 4 and controls the operation of the concrete pump 4 based on the detection value of the level sensor 6. Hereinafter, an example in which the concrete pump 4 is controlled by the level sensor 6 will be described.

  First, as shown in FIG. 3, a rod-shaped level sensor 6 is attached to the tip of an arm 61 extending from the outer periphery of the upper end of the hopper 2 to the approximate center of the insertion port 21 and suspended. And the level sensor 6 is connected to the control part of the concrete pump 4 via an electric cable.

  When the concrete remains sufficiently in the hopper 2, the level sensor 6 is energized because the tip is inserted below the concrete upper surface 2a. For example, this energized state is transmitted as an operation signal through the electric cable to the concrete pump 4, and the concrete pump 4 using the electric motor as a power source is operated.

  When the concrete in the hopper 2 is transported by the operation of the concrete pump 4, the concrete upper surface 2a is gradually lowered and the tip of the level sensor 6 comes out of the concrete upper surface 2a.

  Thus, when the concrete upper surface 2a becomes below a predetermined height and the level sensor 6 is exposed to the air, the energization is stopped. When this energization stop state is transmitted as a stop signal to the concrete pump 4 through the electric cable, the concrete pump 4 stops, and the concrete upper surface 2a is not lowered below that.

  In short, it is sufficient that the concrete pump 4 is stopped by the detection value of the level sensor 6 as a trigger. Then, by linking the level sensor 6 and the concrete pump 4 in this way, it is possible to prevent the concrete pump 4 from being excessively sucked such that the upper part of the vertical pipe 3 becomes hollow.

  Next, the concrete placement method of the present embodiment will be described.

  First, as shown in FIGS. 1 and 2, the hopper 2 is installed at the periphery of the shaft 1 on the ground G, and the vertical pipe 3 having the upper portion 3 a connected to the discharge port 22 is extended downward. The vertical pipe 3 is stretched by connecting a steel pipe having a unit length (for example, a steel pipe having a length of 3 m) so that the vertical pipe 3 can be separated for each driving lift that raises the moving stage 11.

  Then, one end of the horizontal pipe 41 is connected to the lower end 3 b of the vertical pipe 3 disposed above the moving stage 11. The horizontal pipe 41 is laid to the position of the concrete pump 4 on the moving stage 11 and connected to a connection port (not shown) on the upstream side of the concrete pump 4.

  On the other hand, the end of the main pipe 42 a of the branch pipe 42 is connected to a connection port (not shown) on the downstream side of the concrete pump 4. Further, discharge pipes 5 and 5 are connected to respective end portions of the branch pipes 42 b and 42 b of the branch pipe 42. The distal ends of the discharge pipes 5 and 5 are arranged at the concrete placement site on the side wall 10.

  After the concrete placement system is thus installed, a cement-based solidifying material such as mortar is poured from the inlet 21 of the hopper 2. The cement-based solidification material is poured until the entire length of the vertical pipe 3 is filled with the cement-based solidification material.

  Here, since the cement-based solidified material is poured into the hollow vertical pipe 3, it falls freely from the ground G to the depth of the moving stage 11. However, if the mortar does not contain coarse aggregate, material separation is unlikely to occur even if it is dropped freely. In addition, if the cement-based solidifying material to be initially introduced is placed in a place different from the concrete structure such as the side wall 10, the quality of the concrete is not affected.

  And after filling the vertical piping 3 with a cement-type solidification material, concrete is thrown into the insertion port 21 of the hopper 2. For example, concrete with a slump value of about 15 cm is thrown. Subsequently, the concrete pump 4 is operated to convey the cement-based solidified material and concrete.

  As described above, if the interior of the vertical pipe 3 is filled with a cement-based solidifying material in advance and concrete is poured from above, the concrete will not fall freely in the vertical pipe 3 and cause material separation.

  Since the cement-based solidified material is discharged from the discharge pipe 5 at the beginning, it is placed at a location different from the construction location of the side wall 10. And when concrete comes to be discharged | emitted from the discharge pipe 5, the front-end | tip of the discharge pipe 5 is guide | induced to the concrete placement location of the side wall 10. FIG.

  Such concrete placement is continuously performed while concrete is being poured into the inlet 21 of the hopper 2 one after another from the concrete mixer truck. However, if the concrete is stopped due to a delay in the arrival of the concrete mixer truck, the concrete upper surface 2a may be lowered to a predetermined height or less.

  Such a state that the concrete upper surface 2a is lowered to a predetermined height or less is detected by the level sensor 6 and transmitted to the concrete pump 4 as a stop signal. And the concrete pump 4 which received the stop signal stops, and the discharge of the concrete from the discharge pipe 5 stops.

  Thus, if the state where the concrete upper surface 2a exists in the hopper 2 is maintained, even if concrete is thrown in after that, continuity will be maintained and air will not be caught.

  On the other hand, for example, when the next concrete is introduced in a state where the concrete upper surface 2a is lowered to the middle of the vertical pipe 3, air is caught between the concrete remaining in the vertical pipe 3 and the newly added concrete. May result in concrete containing air. In addition, when the distance that has become a cavity in the vertical pipe 3 becomes longer, the newly introduced concrete will fall free for the length of the cavity, so that there is a risk of material separation.

  However, in the concrete placement system of the present embodiment, excessive suction by the concrete pump 4 such that the upper part of the vertical pipe 3 is hollow is prevented by detection of the height of the concrete upper surface 2 a by the level sensor 6.

  Next, the operation of the concrete placement system of the present embodiment and the concrete placement method using the same will be described.

  In the concrete placement system of the present embodiment configured as described above, the hopper 2 on the ground G and the concrete pump 4 disposed on the moving stage 11 below the shaft 1 are connected by the vertical pipe 3. .

  Further, the hopper 2 is provided with a level sensor 6, and the concrete pump 4 is configured to stop when the level sensor 6 detects that the remaining amount of the hopper 2 is equal to or less than a predetermined level.

  By connecting the concrete pump 4 to the downstream side of the vertical pipe 3 in this way, the concrete is continuously conveyed in the vertical pipe 3 based on the suction force of the pump, so that material separation is less likely to occur. be able to. For example, even if the length of the vertical pipe 3 exceeds 60 m, the concrete can be conveyed to the bottom of the shaft 1 without causing material separation.

  If material separation does not occur, the workability and quality of the concrete can be maintained, and it is difficult to cause a situation where coarse aggregate accumulates at the bottom of the vertical pipe 3 and the pipe is clogged. If the vertical pipe 3 is clogged for some reason, the valve 31 of the vertical pipe 3 can be closed to eliminate the clogging.

  And, by configuring so that the concrete pump 4 automatically stops when the remaining amount of the hopper 2 falls below a predetermined level, it is possible to place high-quality concrete without air entrainment. become.

  Further, by interposing the horizontal pipes (41, 42) on the upstream side or the downstream side of the concrete pump 4, it is efficient without moving the position of the vertical pipe 3 even when there is a placement place in a wide range in the horizontal direction. Can be supplied with concrete.

  In this way, if material separation does not occur during conveyance in the vertical pipe 3, the workability of the concrete is maintained, so that conveyance in the horizontal pipe (41, 42) can also be performed efficiently without causing clogging. .

  Furthermore, if the branch pipe 42 is connected to the downstream side of the concrete pump 4 and the discharge pipes 5 and 5 are connected to the respective end portions of the branch pipes 42b and 42b, it is possible to simultaneously connect to a plurality of locations separated in the horizontal direction. Concrete can be supplied.

  Further, in the concrete placing method of the present embodiment, the concrete is put into the hopper 2 after the vertical pipe 3 is filled with a cement-based solidifying material such as mortar, and the concrete pump 4 is operated.

  For this reason, even if it is the concrete thrown in at the beginning of construction, since it does not fall freely in the vertical pipe 3 and material separation does not occur, it can be placed with high quality without wasting all the concrete. it can.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are not limited to this embodiment. Included in the invention.

  For example, in the above-described embodiment, the concrete placement for constructing the side wall 10 of the shaft 1 has been described. However, the present invention is not limited to this, and when constructing an underground structure such as an underground tank or a subway station building. The present invention can also be applied to concrete placement.

  Moreover, in the said embodiment, although the case where horizontal piping (41, 42) was provided in both the upstream and downstream of the concrete pump 4 was demonstrated, it is not limited to this, It is either one. You may or may not have both. Furthermore, the pipe connected to the concrete pump 4 is not limited to the one that extends horizontally, but may extend in an oblique direction or a vertical direction.

  Moreover, although the level sensor 6 was demonstrated as a sensor part in the said embodiment, it is not limited to this, For example, the residual amount of the concrete inside is detected by measuring the weight of the hopper 2 whole. Such a sensor unit may be used.

  Furthermore, in the said embodiment, although concrete was thrown into the hopper 2 after filling the vertical pipe 3 with the mortar as a cement-type solidification material, it is not limited to this, Concrete from the beginning as a cement-type solidification material And the first discharged concrete that may have material separation may not be used to construct a concrete structure such as the side wall 10.

2 Hopper 2a Concrete upper surface 22 Discharge port 3 Vertical piping 3b Lower end 4 Concrete pump 5 Discharge pipe 6 Level sensor (sensor part)

Claims (3)

A concrete placement system for placing concrete in a place with a height difference,
A hopper installed above;
A vertical pipe extending downward from the discharge port of the hopper;
A concrete pump connected to the downstream side of the vertical pipe;
A discharge pipe for supplying the concrete carried out by the concrete pump to the placement site;
A concrete placement system, wherein the hopper is provided with a sensor part for detecting a remaining amount of the concrete introduced, and a signal is transmitted from the sensor part to the concrete pump.   2. The concrete placement system according to claim 1, wherein the sensor unit transmits a signal for stopping the concrete pump when a height of a concrete upper surface in the hopper becomes equal to or lower than a predetermined value. A concrete placement method using the concrete placement system according to claim 1 or 2,
Installing the concrete placing system;
Filling the vertical pipe with a cement-based solidifying material;
Putting concrete into the hopper;
Operating the concrete pump;
And a step of supplying concrete with the discharge pipe directed toward the placement site.