JP2021055267A - Compaction method and apparatus of concrete form - Google Patents

Abstract

To provide a compaction method of a concrete form performing compaction of concrete more surely by giving a vibration inside the concrete installed in a form when installing a tunnel lining concrete.SOLUTION: A vibrated member 20 such as a channel steel is disposed in advance so as to be positioned in a concrete installation space before setting a concrete form 8. A rod-shaped vibration transmission member 25 is inserted into the concrete form 8 via a through hole provided in the concrete form 8 from an outside of the concrete form 8, and a distal end of the vibration transmission member 25 is connected to the vibrated member 20 by a male/female joint part. Then, a vibration of a vibration part (vibrator) 30 disposed outside of the concrete form 8 is transmitted to the vibrated member 20 via the vibration transmission member 25 to compact concrete. After compaction, the connection of the vibration transmission member 25 and the vibrated member 20 is released to remove the vibration transmission member 25 from an inside of the concrete form 8.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method and an apparatus for compacting concrete cast in a mold by applying vibration to the concrete.
The term "inside the formwork" as used herein means a closed space for placing concrete in which at least one surface is partitioned by the formwork.

For example, when placing lining concrete on the inner peripheral surface of a tunnel, the formwork equipped on the mobile center is opposed to the inner peripheral surface of the tunnel at a predetermined interval (for example, 40 cm), and the inner peripheral surface of the tunnel is placed. Place concrete in the lining space between the surface and the formwork.

In addition, during or after placing concrete, a rod-shaped vibrator is inserted while visually observing through a plurality of inspection windows provided on the formwork to give vibration to the placed concrete. The concrete is compacted at.

However, since such compaction work needs to be performed at a large number of locations, it is complicated and inefficient, and there are places where the vibrator cannot reach depending on the mold, so that sufficient compaction is difficult.

Therefore, in recent years, formwork vibrators have been widely used. As described in Patent Document 1, the formwork vibrator is attached to the outer surface of the formwork and vibrates the formwork to vibrate the concrete in the formwork through the formwork. It compacts concrete.

Japanese Unexamined Patent Publication No. 2010-185249

However, when compacting concrete with a formwork vibrator, vibration is added to the concrete surface via the formwork surface (face plate), so it is difficult for vibration to be transmitted to the inside of the concrete, and the compaction of concrete becomes insufficient. was there. In particular, since a large number of reinforcing ribs and the like are formed on the formwork, the vibration is attenuated by these, and the actual situation is that only local vibration is given.

In view of such an actual situation, it is an object of the present invention to make it possible to more reliably compact concrete by applying vibration to the inside of concrete.

The method for compacting concrete in a formwork according to the present invention is a method for compacting concrete placed in a closed space in which at least one surface is partitioned by a formwork.
The step of arranging the vibrated member so as to be located in the closed space, and
A step of inserting a rod-shaped vibration transmitting member into the mold from the outside of the mold through a through hole provided in the mold and connecting the vibration transmitting member to the vibrated member.
A step of transmitting the vibration of the vibrating portion arranged outside the formwork to the vibrated member via the vibration transmitting member and compacting the concrete.
It is characterized by including.
Further, after the compaction, the step of disconnecting the vibration transmitting member and the vibrated member and removing the vibration transmitting member from the mold may be further included.

The compaction device for concrete in a formwork according to the present invention is a device for compacting concrete placed in a closed space in which at least one surface is partitioned by a formwork.
The vibrated member arranged in the closed space and
A rod-shaped vibration transmitting member that is inserted into a through hole provided in the mold, faces the inside of the mold, and is detachably connected to the vibrated member by a joint portion.
A vibrating portion that is arranged outside the mold and gives vibration to the vibration transmitting member,
It is characterized by including.

According to the present invention, the concrete can be compacted from the inside of the concrete to be cast, the concrete can be compacted more sufficiently, and the quality of the concrete to be cast can be improved. It plays the effect.

Longitudinal sectional view of a tunnel in a center-installed state shown as an embodiment of the present invention. Cross-sectional view along the axial direction of the tunnel as above (II-II cross-sectional view of FIG. 1) Top view of the center (formwork) Longitudinal section of the main part of the compaction device Cross-sectional view of the main part of the compaction device (VV cross-sectional view of FIG. 4) Longitudinal cross-sectional view of the support part of the vibrated member (buried steel material)

Hereinafter, embodiments of the present invention will be described in detail with reference to an example of compaction at the time of placing concrete for lining of a tunnel.

FIG. 1 is a vertical sectional view of a tunnel in a center-installed state shown as an embodiment of the present invention, FIG. 2 is a cross-sectional view of the same tunnel along the tunnel axial direction (II-II sectional view of FIG. Is a plan view of the tunnel (form).

The lining of the present embodiment is a secondary lining. Therefore, in the tunnel 1 to be lining, immediately after excavation, the inner peripheral surface (excavation surface) of the tunnel 1 is first lining with sprayed concrete 2, and a waterproof sheet (not shown) is attached to the surface thereof. ing.

In the secondary lining, lining concrete is applied to the inner peripheral surface of the tunnel 1 (inner peripheral surface after the primary lining) above the bottom plate 3 of the tunnel 1 by using a centre (movable formwork device) 4. Place.

The center (movable formwork device) 4 for placing lining concrete moves in the direction of the tunnel axis by a predetermined distance (for example, 10.5 m) of the placing unit, and sets the formwork at each moving position. After that, it is removed from the mold and moved to the next casting position.

The center 4 is a type supported by a gantry (trolley) 5, wheels 6 mounted on the lower part of the gantry 5, a plurality of jacks 7 mounted on the upper part and side of the pedestal 5, and the tip of the jack 7. It is configured to include a frame (panel form) 8.

The gantry 5 can be moved in the tunnel axial direction along a rail (not shown) laid on the bottom plate 3 of the tunnel 1 by the wheels 6, and can be positioned and fixed at an arbitrary moving position.

The jack 7 is provided for positioning the mold 8 (including diameter expansion and diameter reduction), and is used for installing and removing the mold 8.

In the installed state, the formwork 8 forms a lining concrete casting space between the inner peripheral surface of the tunnel 1 (the inner peripheral surface after the primary lining).

More specifically, as shown in FIGS. 2 and 3, the form 8 tunnels the form units 8-1, 8-2, ... With a predetermined width (for example, 1.5 m) in the tunnel axial direction. A plurality (for example, 7 pieces) are connected in the axial direction, and the connection length is configured as one span (for example, 10.5 m) of the casting unit.

Further, the formwork 8 (each formwork unit 8-1, 8-2, ...) Is divided into a plurality of (five in this example) arc-shaped members in the tunnel circumferential direction as shown in FIG. The adjacent arc-shaped members are hinged to each other. As a result, the formwork 8 has an arch shape as a whole and can be bent at the connecting portion.

Regarding the lining concrete casting space, the outer peripheral side is partitioned by the inner peripheral surface of the tunnel 1 (inner peripheral surface after the primary lining), the inner peripheral side is partitioned by the formwork 8, and one end in the tunnel axial direction (wellhead). The side end; wrap side) is partitioned by the existing lining concrete 9 (FIG. 2), and the other end (face side end; gable side) in the tunnel axial direction is partitioned by the end formwork 10 (FIG. 2). It becomes a closed space.

For placing concrete in the lining concrete placing space partitioned by the formwork 8 as described above, an appropriate opening / closing port (not shown) provided in the formwork 8 and / or a wife formwork A concrete casting pipe is inserted from an opening / closing port (not shown) provided in No. 10, and concrete is pumped to fill the lining concrete casting space with concrete. The filling here is performed from the left and right side portions of the tunnel, passes through the left and right arch portions, and finally fills up to the top end portion. As the concrete, medium-fluidity concrete is preferably used.

During the placement of such concrete, particularly during the placement on the top end, vibration is applied to the concrete at the top end to compact the concrete.

The compaction device used here will be described below with reference to FIGS. 4 to 6 in addition to FIGS. 1 to 3.
FIG. 4 is a vertical cross-sectional view of the main part of the compaction device, FIG. 5 is a cross-sectional view of the main part of the compaction device (VV cross-sectional view of FIG. 4), and FIG. It is a vertical sectional view of a part.

The compaction device of the present embodiment is inserted into the vibrated member 20 arranged inside the formwork 8 (inside the concrete casting space) and the through hole 8a provided in the formwork 8 into the formwork 8. A rod-shaped vibration transmitting member 25 whose tip is detachably connected to the vibrated member 20 by a male and female joint portion, and a vibrating portion (vibrator) which is arranged outside the formwork 8 and gives vibration to the vibration transmitting member 25. ) 30 and.

The vibrated member 20 is made of a steel material, more preferably channel steel (or lip channel steel), and is bent in an arch shape along the inner peripheral surface of the tunnel 1 with the groove opening outward (upward). It is done.
The vibrated member 20 is arranged in the lining concrete placing space prior to the installation of the formwork 8. Specifically, the vibrated member 20 is separated from the inner peripheral surface of the tunnel 1 and the formwork 8 at the top end of the arch-shaped lining concrete placing space when viewed in the tunnel axial direction as shown in FIG. And arrange them in an arc shape concentric with these.

As shown in FIGS. 2 and 3, a plurality of vibrated members (steel materials) 20 are also used and arranged at predetermined intervals in the tunnel axial direction. In the present embodiment, the same number of vibrating members 20 as the formwork units constituting the formwork 8 are arranged at the same intervals as the width of the formwork unit, but a small number of vibrating members 20 are provided as long as necessary and sufficient compaction performance can be obtained. The vibrating members 20 may be arranged at wider intervals.

Further, the vibrated member (steel material) 20 is supported by at least two support portions 22 so as to be arranged at a predetermined position in the lining concrete placing space as described above.

More specifically, the support portion 22 is configured as shown in FIG. That is, using an anchor bolt (or reinforcing bar) 22a that has been drilled in the inner peripheral surface of the tunnel and injected with cement milk, a tightening nut 22b is attached to the end of the anchor bolt 22a protruding from the inner peripheral surface of the tunnel 1. Fix with etc. The fixing here may have some play so as to promote vibration.
Further, when there is a support work such as H-shaped steel on the inner peripheral side of the tunnel 1, a support member may be projected from the support work and supported by the support member.

The vibration transmission member 25 is made of a rod-shaped steel material, more preferably a carbon steel pipe for piping generally called a “gas pipe” or a “SGP pipe”.
After the mold 8 is installed, the vibration transmitting member 25 is inserted into the through hole 8a provided in the mold 8 so that the tip of the vibration transmitting member 25 faces the inside of the mold 8 and the tip of the vibration transmitting member 25 is connected to the vibrated member 20 by a male and female joint portion. Detachable connection.

Specifically, as shown in FIGS. 4 and 5, a pipe joint 23 is fixed in advance to the lower surface of the central portion of the vibrated member 20, and a male formed on the outer periphery of the tip portion of the vibration transmitting member 25. The vibration transmission member 25 can be fixed to the vibrated member 20 by screwing the screw into the female screw of the pipe joint 23 on the vibrated member 20 side. By using a male and female joint portion (pipe joint 23, etc.), the vibration transmitting member 25 can be easily attached and detached by rotating the vibration transmitting member 25 from the outside of the mold 8.
A pipe joint 28 is fixed to the base end side of the vibration transmitting member 25 outside the form 8 for vibration receiving.

As the vibrating portion 30, a mold vibrator is diverted, and instead of vibrating the mold, the vibration transmitting member 25 is vibrated. The formwork vibrator rotates an eccentric member by rotation of a motor to generate vibration in a direction orthogonal to the vibration surface 30a on the vibration surface 30a. Therefore, by contacting or fixing the vibration transmitting surface 30a to the end portion (vibration receiving pipe joint 28) of the vibration transmitting member 25, the vibration transmitting member 25 can be vibrated in the axial direction by the vibration transmitting surface 30a.

Next, the compaction method (compacting procedure) using the above-mentioned compaction device will be described in the order of steps.

(1) Placement process of vibrated member The vibrated member 20 is placed by being supported by the support portion 22 so as to be located in the concrete casting space before the formwork 8 is installed. If the vibrated member 20 is arranged in the concrete casting space before the formwork 8 is installed, it does not necessarily have to be supported by the support portion 22.

(2) Vibration Transmission Member Connection Process After the formwork 8 is installed, before concrete is placed or during the placement (after the start of casting), through the through hole 8a provided in the formwork 8 from the outside of the formwork 8. A rod-shaped vibration transmitting member 25 is inserted into the mold 8 to connect the vibration transmitting member 25 to the vibrated member 20. In the present embodiment, the tip of the vibration transmission member 25 is screwed into the vibrated member 20 by a male and female joint portion (pipe joint 23, etc.).

(3) Concrete compaction process The vibrating portion (vibrator) 30 arranged on the outside of the form 8 is operated, and the vibration is transmitted to the vibrated member 20 via the vibration transmitting member 25 to cause the vibrated member 20 to be vibrated. The concrete is compacted by vibrating. As a result, vibration can be directly applied to the concrete from the inside of the concrete, and the entire concrete can be satisfactorily compacted.

(4) Vibration Transmission Member Removal Step After the above compaction, the connection between the vibration transmission member 25 and the vibrated member 20 is released, and the vibration transmission member 25 is removed from the mold 8. After the removal, an appropriate lid (such as a fitting type cap) is attached to the through hole 8a of the mold 8. Therefore, the steel material which is the vibrated member 20 is left in the mold 8. The vibrated member 20 may be a buried steel material that also serves as a reinforcing steel material.

When the vibration transmission member 25 is removed, a hole may remain at the position where the vibration transmission member 25 is located, depending on how the vibration transmission member 25 is removed.
As a countermeasure against such concerns, it is preferable to implement any of the following methods (5-1) to (5-3).

(5-1)
When the vibration transmission member 25 is removed from the mold 8, the vibration transmission member 25 is removed while being vibrated by the vibration generating portion 30. As a result, the concrete in the vicinity of the through hole 8a can be blended, and the occurrence of punched holes and the like can be suppressed.

(5-2)
After the vibration transmitting member 25 is removed from the mold 8, a rod-shaped vibrator is inserted through the through hole 8a of the mold 8 to further compact the concrete in the vicinity of the through hole 8a. As a result, the concrete in the vicinity of the through hole 8a can be vibrated and agitated to eliminate the punched hole.

(5-3)
After removing the vibration transmitting member 25 from the inside of the mold 8, the through hole 8a is covered, and then the mold 8 (the face plate thereof) near the through hole 8a is vibrated by the mold vibrator to vibrate the through hole 8a. Further include the step of compacting the concrete. As a result, the concrete in the vicinity of the through hole 8a can be vibrated and blended, and the punched hole can be eliminated.

In the above embodiment, the example of compaction at the time of placing concrete for lining of a tunnel has been described, but in the present invention, at least one surface is compacted at the time of placing concrete in a closed space partitioned by a formwork. It can be applied to concrete.

Moreover, the illustrated embodiment is merely a schematic example of the present invention, and the present invention is made by a person skilled in the art within the scope of claims in addition to the one directly shown by the described embodiment. Needless to say, it includes improvements and changes in.

1 Tunnel to be lining 2 Sprayed concrete 3 Bottom board 4 Centre 5 Mount (trolley)
6 Wheels 7 Jack 8 Formwork 8-1-8-7 Formwork unit 8a Through hole 9 Existing lining concrete 10 Formwork 20 Vibrated member (buried steel material)
22 Support part 22a Anchor bolt 22b Tightening nut 23 Pipe joint 25 Vibration transmission member 28 Pipe joint for vibration receiving 30 Vibration part (vibrator)
30a Vibration surface

Claims (7)

A method of compacting concrete placed in a closed space where at least one surface is partitioned by a formwork.
The step of arranging the vibrated member so as to be located in the closed space, and
A step of inserting a rod-shaped vibration transmitting member into the mold from the outside of the mold through a through hole provided in the mold and connecting the vibration transmitting member to the vibrated member.
A step of transmitting the vibration of the vibrating portion arranged outside the formwork to the vibrated member via the vibration transmitting member and compacting the concrete.
How to compact concrete in formwork, including. The concrete in a formwork according to claim 1, further comprising a step of disconnecting the vibration transmitting member and the vibrated member after the compaction and removing the vibration transmitting member from the formwork. Compaction method. The method for compacting concrete in a formwork according to claim 2, wherein when the vibration transmitting member is removed from the formwork, the vibration transmitting member is removed while vibrating. The method for compacting concrete in a form according to claim 2 or 3, further comprising a step of compacting the concrete in the vicinity of the through hole after removing the vibration transmitting member from the form. The form according to any one of claims 1 to 4, wherein the formwork is a formwork for tunnel lining concrete arranged at intervals from the inner peripheral surface of the tunnel. How to compact concrete in the formwork. The tightening of concrete in a formwork according to any one of claims 1 to 5, wherein the vibration transmitting member and the vibrated member are connected via a detachable joint portion. Hardening method. A device that compacts concrete placed in a closed space where at least one surface is partitioned by a formwork.
The vibrated member arranged in the closed space and
A rod-shaped vibration transmitting member that is inserted into a through hole provided in the mold, faces the inside of the mold, and is detachably connected to the vibrated member by a joint portion.
A vibrating portion that is arranged outside the mold and gives vibration to the vibration transmitting member,
In-formwork concrete compaction device, including.

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