JP3979646B2 - Concrete building repair method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a concrete building repair method capable of repairing a concrete building while ensuring a good working environment without generating mechanical impact.
[0002]
[Prior art]
For example, Patent Document 1 shows a seismic reinforcement method for an existing reinforced concrete structure in which concrete of a reinforced concrete structure is crushed and removed by a water jet, and reinforcing reinforcing bars are arranged and reinforced. In this seismic retrofitting method, existing reinforced concrete structures such as piers on expressways are not cut, but water jets are used to remove the concrete in the vertical direction of the existing reinforced concrete and provide slits. Reinforce reinforcing bars in combination with reinforcing bars. Since it can be reinforced by covering the surface of existing reinforcing bars and reinforcing bars with thick concrete, there is no risk of damaging existing reinforcing bars, and the environment such as noise, vibration, and dust can be greatly improved, and the labor saving of construction can be greatly reduced. Can be planned.
[0003]
Patent Document 2 removes concrete on a concrete web surface that fixes a FRP lattice including lightweight, high-strength continuous fibers by using a water jet, fixes a rivet anchor to the FRP lattice, and fills and solidifies the concrete. A method for reinforcing concrete structures is shown. This method of reinforcing a concrete structure includes a concrete web surface including an FRP lattice formed by arranging a plurality of reinforcing bars in a lattice shape, a concrete bar member fixing the FRP lattice, and a fixed FRP lattice. A concrete structure having a cent mortar or polymer mortar that is thickened by coating on the side is subjected to a ground treatment by removing the concrete on the concrete web surface by a water jet. Next, rivet anchors are driven into the concrete web surface to which the FRP lattice is fixed, and the concrete structure has high shear reinforcement by holding it firmly and reinforcing and reinforcing the FRP lattice to the concrete web surface. Get the effect.
[0004]
Patent Document 3 shows a road repairing method in which concrete on a concrete roadbed is removed by a water jet, and a reinforcing reinforcing bar is placed on an exposed reinforcing bar to place concrete. In this road repair method, water is sprayed at a high speed by a water jet on one surface of a concrete roadbed including concrete adhered to a plurality of reinforcing bars in the road width direction and the road length direction, and the concrete surface is removed by water pressure. To expose the rebar. Next, a primary reinforcing reinforcing bar is arranged in the road width direction on the exposed reinforcing bar, and concrete is placed. Water is also sprayed onto the other surface of the concrete roadbed by a water jet to remove the concrete surface. Similarly, concrete is placed by placing secondary reinforcing bars in the road width direction on the exposed reinforcing bars. In addition, since a joint having a male screw is provided between the primary reinforcing bar and the secondary reinforcing bar, the reinforcing bars are continuously joined and strengthened in the road width direction and the road length direction of the concrete roadbed.
[0005]
[Patent Document 1]
JP-A-9-67942 (2nd page)
[Patent Document 2]
JP 2002-129753 A (page 2)
[Patent Document 3]
JP 2002-180417 A (page 3)
[0006]
[Problems to be solved by the invention]
In the conventional concrete building repair method, since all the concrete at the repair site is removed by the water jet, the repair requires labor and time, and the repair work cannot be completed in a short period of time. Also, for example, when a concrete building is crushed using a sawing and cutting device such as wire sawing, wall sawing or drill sawing, microcracks are produced in healthy reinforcing bars and concrete materials due to large impacts and vibrations generated when the concrete materials are destroyed. In addition to damage such as the above, vibration and noise are generated, and the dust of the concrete material is scattered around, which adversely affects the environment. In order to reinforce the concrete building after cutting the concrete building using the sawing and cutting device, the concrete material is further pierced and an adhesive such as epoxy resin is injected into the formed recess. After that, the reinforcing reinforcing bars are inserted into the recesses and bonded to the recesses by the epoxy resin, so that there is a disadvantage that the mechanical strength is extremely insufficient because the reinforcing bars are not connected to the existing reinforcing bars.
Then, an object of this invention is to provide the concrete building repair method which can be completed in a short time, without generating a big impact and vibration in a concrete building at the time of repair.
[0007]
[Means for Solving the Problems]
In the concrete building repair method according to the present invention, a plurality of metal frames (4) and a concrete material (5) fixed around the plurality of frames (4) using the plurality of frames (4) as a skeleton. Water flow from the nozzle (6) toward the wall (3) of the concrete building (1) including the formed foundation (2) and the wall (3) formed integrally with the foundation (2). The surface of the concrete building (1) is crushed by ejecting at high speed. Due to the hydro-demolition method, large impacts and vibrations do not occur in the concrete building (1), and damage such as microcracks does not occur in the frame (4). Further, the surface layer of the concrete building (1) can be crushed efficiently, safely and without deteriorating the environment. Further, the water flow is ejected from the nozzle (6) at high speed, and the concrete material (5) is completely crushed and removed from the concrete building (1) in the thickness direction, and an opening is formed in a part of the wall (3). Form (7). Next, the nozzle (6) is moved to leave the foundation (2) and the unmachined part (8) (Mihamariburi) in the concrete building (1), and the opening (7) is formed in a strip shape. As a result, a part of the frame (4) embedded in the concrete material (5) is exposed in the opening (7). Since the concrete material (5) in the opening (7) has already been removed, the frame (4) exposed in the opening (7) can be easily cut. Thereafter, the uncut portion (8) of the concrete material (5) separated by cutting is removed. Subsequently, after fixing the reinforcing frame (9) to the frame (4) exposed from the concrete material (5), the concrete material is supplied around the reinforcing frame (9) to solidify the concrete material. In this way, the foundation part (2) with a usable life of the concrete building (1) is left and can be used as it is after the repair, so the foundation part (2) can be used effectively and the repair work period can be shortened. .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a concrete building repair method according to the present invention will be described with reference to FIGS.
[0009]
In the concrete building repair method according to the present embodiment, first, as shown in FIG. 1, a plurality of metal frames (4) and a plurality of frames (4) as a skeleton around a plurality of frames (4). A wall portion of a concrete building (1) including a base portion (2) formed by a concrete material (5) fixed to a wall portion (3) formed integrally with the base portion (2) ( A water stream is ejected from the water jet nozzle (6) at a high speed toward 3), and the surface layer of the concrete building (1) is crushed by the hydro-demolition method. In the present embodiment, the concrete building (1) is an overpass, the foundation (2) is a bridge, a pier or a bridge girder, and the wall (3) is a balustrade. The water jet used has a structure in which water applied with a pressure of 100 MPa is jetted from a nozzle (6) having a diameter of 2 to 3 mm to the concrete building (1) at a flow rate of 200 liters per minute. The water speed to be ejected is Mach 1 to Mach 7, preferably 500 m / s to 1000 m / s. In the illustrated example, the plurality of reinforcing bars (4) are connected to each other by a fastening tool such as a wire or a fixing tool (11) and embedded in the concrete material (5) of the concrete building (1). Since the jet water flow collides with the concrete building (1), the concrete building (1) is not subjected to large impacts and vibrations, and the rebar (4) is not damaged such as microcracks. The surface of the concrete building (1) can be crushed efficiently and safely without deteriorating the environment.
[0010]
Further, a water flow is ejected from the nozzle (6), and the concrete material (5) is completely crushed and removed from the wall (3) in the thickness direction, and an opening (7) is formed in a part of the wall (3). ). Although the impact area of the water flow spouted from the nozzle (6) on the concrete structure (1) is extremely small, the impact force is large, so an opening (7) is formed by crushing in the thickness direction of the concrete structure (1). Thus, the concrete material (5) can be completely crushed and removed from the concrete building (1). In this case, if a protective film such as a protective sheet is arranged behind the concrete building (1), dust can be completely prevented from being scattered around. Moreover, since dust absorbs the water | moisture content by a water jet and increases mass, since it falls immediately with the fall of a kinetic energy after being blown away in the air, it does not scatter very much. However, it is desirable to dispose of the crushed waste of the concrete material (5) at a predetermined place before drying. When the diameter of the reinforcing bar (4) is d, the width (L) of the opening (7) where the reinforcing bar (4) in the opening (7) is exposed is, for example, 10d to 50d, preferably 25d to 45d. Is in range. The reinforcing bar (4) exposed in the opening (7) is connected to the basic reinforcing bar (4) or the basic steel frame embedded in the basic part (2).
[0011]
Next, moving the nozzle (6) horizontally and vertically while leaving the foundation (2) and the unmachined part (8) in the concrete building (1), the unmachined part In parallel with (8), the concrete material (5) is crushed with a certain width and a certain length, and a part of the reinforcing bar (4) embedded in the concrete material (5) is exposed in a strip shape. In the hydro-demolition method, it is possible to crush the concrete material (5) in the desired area of the concrete building (1) by moving the nozzle (6) to form the opening (7). . Like the wire sawing, wall sawing or drill sawing methods, the concrete part (5) or the reinforcing bar (4) constituting the foundation part (2) is subjected to impact or vibration to cause damage such as microcracks (2). It is possible to completely prevent harmful effects on Moreover, since the base part of the concrete structure where durability remains can be used as it is, resource reduction can be achieved.
[0012]
When cutting the rebar (4) exposed along the horizontal plane (12) of a certain height from the reference plane of the concrete building (1), the concrete material (5) has already been removed, so the concrete building (1 The rebar (4) exposed along the horizontal plane (12) having a certain height from the reference plane or the vertical plane (13) spaced a certain distance from the reference vertical plane can be easily cut. Then, as shown in FIG. 2, the wire (10) is wound around the uncut portion (8) of the concrete material (5) separated by cutting, and the uncut portion (8) is removed.
[0013]
Next, as shown in FIG. 3, a binding wire (11) such as a wire is wrapped around the reinforcing bar (4) exposed from the concrete material (5), and the reinforcing bar (reinforcement frame) (7) is wrapped around the reinforcing bar (4). Fix it.
[0014]
Finally, as shown in FIG. 4, the concrete material is supplied around the reinforcing frame (9) to solidify the concrete material. Moreover, since the foundation part (2) with a useful life of the concrete building (1) is left and can be used as it is after the repair, the foundation part (2) can be used effectively and the repair work period can be shortened.
[0015]
The above-described embodiment of the present invention can be modified. For example, in Fig. 1, the horizontal opening (7) is formed in the concrete building (1), the rebar (4) is cut along the horizontal plane (12), and the uncut portion (8) is removed. As shown in FIGS. 5 and 6, a vertical opening (7) is formed in the concrete building (1), the rebar (4) is cut along the vertical surface (13), and uncut. The part (8) may be removed. Further, the opening (7) is not limited to a rectangle or a square having a constant width or an arbitrary width, and can be formed in various shapes such as an arc shape and a waveform. Furthermore, instead of the concrete building (1) using the reinforcing bar (4), the present invention is also applied to a concrete building (1) having a plurality of steel frames joined together as a frame or a combination structure of reinforcing bars and steel frames. be able to. For a concrete structure (1) built using steel, if one of the vertical or horizontal dimensions of the rectangular cross section of the steel frame is d, the width of the opening (7) where the frame (4) is exposed is It is in the range of 10d to 50d, preferably 25d to 45d. In addition, the present invention can be applied to general or special concrete structures such as buildings other than overpasses, stadiums, dams, weirs, warehouses, revetments, and dredging walls.
[0016]
In the embodiment of the concrete building repair method according to the present invention, the following effects are obtained.
[1] Hydrodemolition that efficiently crushes only a part of concrete from the concrete building (1) does not give mechanical shock and vibration to the concrete building (1) and has environmental compatibility.
[2] Compared to wire sawing, wall sawing or drill sawing, where a concrete building (1) is mechanically cut with a cutter to generate a large amount of noise, a water jet that produces only the water flow noise of jet water is less sensitive to noise. It can be significantly reduced.
[3] Because mechanical shock and vibration are not applied to the concrete building (1), it is possible to completely prevent the occurrence of fragile parts such as small cracks and cracks in the reused concrete building (1). .
[4] Since the wall is rebuilt using the sound reinforcement (4) of the foundation (2), the construction period can be greatly shortened and the construction cost can be greatly reduced.
[5] If a protective film, such as a sheet, is placed behind the concrete building (1) and cured, the water jet dust absorbs moisture and increases its mass, so it is possible to completely disperse to the surroundings. It can be prevented and can be constructed with low pollution.
[6] Fully self-propelled system by remote control of nozzle (6), unmanned water flow crushing becomes possible.
[7] The concrete structure (1) can be given a strength substantially equal to or higher than that of the concrete structure (1) before repair.
[0017]
【The invention's effect】
As described above, the present invention has an advantage that the concrete building can be repaired without damaging the foundation of the concrete building and without generating large impact, vibration and dust.
[Brief description of the drawings]
[Fig. 1] A perspective view showing a state where a surface layer of a concrete building is crushed by a hydro-demolition method to form a horizontal opening. [Fig. 2] A perspective view showing a state where an uncut portion is removed from a foundation portion. [Fig. 3] Perspective view showing the state in which the reinforcing frame is fixed to the exposed frame [Fig. 4] Perspective view of the concrete structure reconstructed by supplying concrete around the reinforcing frame [Fig. 5] Concrete by the hydro-demolition method FIG. 6 is a perspective view showing a state in which a surface layer surface of a building is crushed to form a vertical opening. FIG. 6 is a perspective view showing a state in which an uncut portion shown in FIG. 5 is removed from a base portion.
(1) ... Concrete building, (2) ... Foundation, (3) ... Uncut part, (4) ... Reinforcement (frame), (5) ... Concrete material, (6) ... Nozzle , (7) ・ ・ Opening, (8) ・ ・ Uncut part, (9) ・ ・ Reinforcement frame,

Claims (5)

A concrete structure including a plurality of metal frames, a foundation portion formed of a concrete material fixed around the plurality of frames using the plurality of frames as a skeleton, and a wall portion formed integrally with the foundation portion The process of crushing the surface layer of the wall by ejecting a water flow from the nozzle at high speed toward the wall of
Furthermore, a process of ejecting a water flow from the nozzle at high speed to completely crush and remove the concrete material from the wall in the thickness direction to form an opening in a part of the wall,
A part of the frame embedded in the concrete material is placed in the opening by moving the nozzle and forming the opening in a band shape while leaving the foundation part and the uncut part in the concrete building. The process of exposing,
Cutting a plurality of frames exposed in the opening, and separating the uncut portion from the base portion;
The process of removing the uncut parts of the separated concrete material;
Fixing the reinforcing frame to the frame exposed from the concrete material;
A method for repairing a concrete structure, comprising: supplying concrete material around a reinforcing frame to solidify the concrete material. The frame is a reinforcing bar or a steel frame, and the width of the opening from which the frame is exposed is in the range of 10d to 50d, where d is the diameter of the reinforcing bar or the vertical or horizontal dimension of the rectangular cross section of the steel frame. Concrete building repair method described in 1. The concrete building repair method according to claim 1, wherein the frame embedded in the concrete material of the concrete building is connected to the frame embedded in the foundation portion of the concrete building. The cutting of the frame exposed in the opening includes cutting the exposed frame along a horizontal plane at a certain height from a reference plane of the concrete building or a vertical plane spaced a certain distance from the reference vertical plane. The concrete building repair method according to any one of? The process of exposing a part of the frame in the band-shaped opening includes a process of moving the nozzle in the horizontal direction and the vertical direction to form the opening with a certain width and a certain length in parallel with the uncut part. The concrete building repair method according to any one of claims 1 to 4.

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