JP2011157734A - Method of waterstop by rear face injection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of waterstop by rear face injection efficient and assured waterstop at (1) a position where there are a number of densely-formed water-leaking cracks, (2) a position where water leakage is observed through gaps of concrete texture (a honeycomb or a candied bean slab), and (3) a position where a water leakage route cannot be identified, which have not been resolved completely by conventional technologies. <P>SOLUTION: The method of waterstop by rear face injection includes a step of forming an injection hole penetrating from the front face toward the rear face of a concrete structure, a step of injecting a waterstop agent into the injection hole, and a step of forming a waterstop film between the rear face of the concrete structure and covering soil in contact with the rear face of the same, by hardening the waterstop agent. In the method, the waterstop agent used in the step of injecting the waterstop agent contains at least an aqueous-polymer-based dispersion liquid and a hardening accelerator. The specific gravity of the waterstop agent is 1.03-1.04. In the step of forming the waterstop film, the waterstop agent is radially spread from an outlet port of the injection hole over the rear face, and then is hardened. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a back surface injection water stop method, and more particularly to a back surface injection water stop method in which a water stop agent is injected into the back surface of a concrete structure in order to stop water leakage of the concrete structure.

  Water leaks and rain leaks from civil engineering and building structures are very hindrances in the use and use of such structures. In particular, when the structure is a concrete structure such as reinforced concrete, there is a risk of water leakage from cracks, cold joints, jumpers, etc. of the structure. This leakage causes rusting of internal rebar and neutralization of concrete. Advances, and the durability of the structure itself is significantly reduced.

  As measures for preventing such water leakage, a water conveyance method, a seal method, a filling method, and an injection method are known.

  In the water guide method, water leakage is not stopped, but water is led to a location with few obstacles by dredging, hose embedding, grooving, etc., and let it escape. However, in this construction method, free lime and the like are deposited inside the water conduit, blockage, and water leaks again in a short time. In addition, early deterioration of reinforced concrete cannot be stopped and is only temporary.

  The sealing method is a method of closing an outlet that leaks water by sealing cracks and various joints from the front side. There are various types of sealing materials such as polymer and inorganic cement. However, there is a problem that water leakage starts at another nearby location when the outlet of the water leakage is blocked. Moreover, there is a problem that the durability of the sealing material is short and water leaks again in a short time. Although this method has a short-term effect on very slight water leakage, it is not a full-scale water stop method.

  The filling method is a method in which the gap in the water leakage path is suspended from the front side, and the gap that can be identified as the cause of water leakage such as cracks, joints, joints, and cold joints is closed. However, this method involves a work of lifting, and a large amount of construction waste such as noise, dust, and concrete glass is generated, and the water stop effect is unstable at a high cost.

  The injection method is a method of injecting a water-stopping agent into the gap of the water leakage path, and injecting the water-stopping agent into the gap of the water leakage path that can be specified to close the gap from the front side. The water-stopping agent is press-fitted from an injection hole drilled in the concrete. Since the void is closed inside the structure, this method is effective as a countermeasure against water leakage in a limited area that can be specified. However, it is unsuitable as a water stop construction method for places where there are many water cracks, high density, places where water leaks from voids in the concrete structure (junka, beans), and places where the water leak path cannot be specified.

  For this reason, the back surface injection water stop construction method which forms the injection hole which penetrates a wall surface in a concrete structure, and inject | pours a water stop agent into the back surface of this structure from this injection hole is proposed (patent document 1). According to this method, water leakage is blocked at the water ingress side by the water-stopping agent injected into the back surface of the structure, so the water-stopping effect is high, due to rusting of internal rebar due to water and neutralization of concrete It is thought that early deterioration can be prevented and the durability of concrete structures can also be improved.

JP-A-5-247958

  2. Description of the Related Art Conventionally, as such a back surface injection water stop method, a method (super lock method) that uses a water stop agent in which fine particle cement is made into a slurry is known. The water-stopping agent is injected from the injection hole to the back surface of the concrete structure using a pump, thereby forming a water-stop film on the back surface of the concrete structure.

  However, since the cement slurry-like water stop agent has a large specific gravity of 2.0 to 3.0, when such a water stop agent is injected from the injection hole to the back surface of the concrete structure, the area around the outlet of the injection hole Then, it slightly diffuses due to the influence of the injection pressure, but particularly on the vertical wall surface, as shown in FIG. 5, it immediately sinks downward from the outlet of the injection hole 10. For this reason, a water-stop film cannot be formed in a wide range around the injection hole 10 but only a local water-stop film 20 is formed. When it exists or when the water leakage path cannot be specified, there is a problem that a very large amount of water stopping agent must be injected to form an effective water stopping film.

  Therefore, the present invention is such that the water-stopper injected from the injection hole to the back surface side of the concrete structure is diffused radially from the injection hole outlet along the back surface without sinking downward, even on the vertical wall surface. By making it possible to form a water-stopping film over a wide range, it was incomplete in the prior art (1) where there are many water-cracking cracks at high density, and (2) from the voids in the concrete structure It is an object of the present invention to provide a back surface injection water stop construction method capable of performing efficient and reliable water stop for locations where water leaks (junka, bean plate) and (3) locations where a water leak path cannot be specified.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

(Claim 1)
Providing an injection hole penetrating from the surface of the concrete structure toward the back surface;
Injecting a water-stopper into the injection hole;
In the back-side water-stopping construction method, comprising a step of forming a water-stopping film obtained by curing the water-stopping agent between the back surface of the concrete structure and the covered soil in contact with the back surface,
The water stopping agent used in the step of injecting the water stopping agent includes at least an aqueous polymer dispersion and a curing accelerator, and the specific gravity of the water stopping agent is 1.03 to 1.04.
The back surface injection water stop method is characterized in that the step of forming the water stop film diffuses and hardens radially along the back surface centering on the outlet of the injection hole.

(Claim 2)
The step of forming the water blocking film diffuses radially on the back surface of the vertical wall of the concrete structure, centering on the outlet of the injection hole, and along the back surface, and upward diffusion than the area of the lower diffusion region The back-surface injection water-stop method according to claim 1, wherein the area is diffused and hardened so that the area of the region increases.

  According to the present invention, the specific gravity of the water-stopping agent injected from the injection hole to the back side of the concrete structure is 1.03 to 1.04, which is not different from water. It is diffused and hardened radially along the back surface, and for the vertical wall, it is diffused and hardened so that not only the radial diffusion but also the area of the upper diffusion region is larger than the area of the lower diffusion region. Thus, a waterproof film over a wide range can be formed. As a result, the conventional technology was incomplete (1) where there were many water cracks and high density, (2) where water leaked from the voids in the concrete structure (junka, beans), (3) water leak path It is possible to efficiently and surely stop the water at a location where cannot be specified.

Photograph showing the state of injection and diffusion confirmation tests using a water stopping agent with a specific gravity of 1.03 to 1.04 Photograph showing the state of injection and diffusion confirmation tests using a water stopping agent with a specific gravity of 1.03 to 1.04 Photograph showing the state of injection and diffusion confirmation tests using a water stopping agent with a specific gravity of 1.03 to 1.04 Sectional drawing which shows the example which applies the back surface injection water stop construction method concerning this invention as a leaking measure of a tunnel The figure which shows a mode that the conventional cement slurry-like water stop agent was inject | poured into the back surface of the concrete structure from the injection hole.

  The 1st process of this invention is a process of providing the injection hole penetrated toward the back surface from the surface of a concrete structure.

  The concrete structure in the present invention is generally a structure constructed by pouring concrete into a mold, and typically includes reinforced concrete, precast concrete, ALC (lightweight cellular concrete), It may be a brick structure.

  Specific examples of such concrete structures include tunnels (including common grooves), irrigation channels, various water tanks, underground pits such as buildings, condominiums, residential basements and elevators, and underground parking lots.

  The back surface of the concrete structure is in contact with a covering such as soil containing water, SMW (Soil Mixing Wall), sheet pile, or the like. The reason for expressing water-containing soil is as follows. For example, in the case of a tunnel, water pressure is usually applied to the back surface, and the back surface is not uniformly covered with the covered soil. A part where water is in direct contact with the back surface and a part where the covered soil is in contact are mixed. For this reason, the object which coat | covers the back surface of a concrete structure is expressed as "the soil containing water."

  In the present invention, the present invention can be applied as a measure against water leakage from the back surface of a concrete structure, and the present invention exhibits a good water stop effect even for a vertical wall.

  The method of forming the injection hole is influenced by the thickness of the structure. For example, if the thickness is 1000 mm or less, the injection hole is formed with a diameter of about 10 mmφ with a drill or the like. If it is thicker than that, an injection hole exceeding 10 mmφ is formed using a core machine, a rock drill or the like.

  In the present invention, there is an effect that the number of injection holes can be reduced as compared with the conventional method. This is because the diffusion range of the water-stopping agent described later is wide and the area of the water-stopping range of one hole is large in order to diffuse more upward.

  The second step is a step of injecting a water-stopping agent into the injection hole formed in the first step, and the third step is between the back surface of the concrete structure and the covered soil in contact with the back surface. This is a step of forming a water-stop film in which the water-stop agent is cured.

  In the present invention, the water stopping agent includes at least an aqueous polymer dispersion and a curing accelerator, and the specific gravity of the water stopping agent is 1.03 to 1.04.

  In addition to the aqueous polymer dispersion and the curing accelerator, the water-stopping agent of the present invention can contain dilution water and the like.

  In the present invention, the specific gravity of the water-stopping agent can be measured with a hydrometer, for example, after being put into a 1 liter graduated cylinder, it can be measured with a buoy.

  In the present invention, the specific gravity of the water-stopping agent is important, and since the specific gravity is very close to water, when injected into the back surface of a concrete structure (the back surface contains water that is a source of water leakage), injection Even if the location is a vertical wall surface, many of them diffuse radially upward along the back surface, with the outlet of the injection hole as the center.

  The injected water-stopping agent spreads over a wide area around the outlet of the injection hole as time passes.

  The back surface water-stop method of the present invention can be applied not only to the back surface of the vertical wall but also to the back surface of the ceiling surface and the floor surface.

  If the waterproofing agent is injected into the back of a horizontal wall (for example, ceiling or floor), the specific gravity will be 1.03 to 1.04, so it will not float in water and will diffuse radially along the back. To do.

  Moreover, if the water-stopping agent is injected into the back of the vertical wall, it does not settle downward, but conversely diffuses radially, and the area of the upper diffusion region becomes larger than the area of the lower diffusion region. To diffuse. Here, the lower diffusion region is a region below the horizontal line based on the injection hole, and the upper diffusion region is a region above the horizontal line based on the injection hole.

  In the present invention, the injected water-stopping agent diffuses in a wide radial range along the back surface of the concrete structure, and is cured after a predetermined time to form a water-stopping film.

  For this reason, there are many water leakage cracks that were incomplete with conventional technology, high density locations, locations where water leaks from voids in the concrete structure (junka, bean plate), and locations where the water leakage path cannot be identified. And reliable water stop can be achieved.

  The aqueous polymer dispersion used in the present invention is, for example, a simple substance of petroleum asphalt (straight, blown) or thermoplastic resin (butadiene resin, ethylene vinyl acetate, petroleum resin) or a combination of two or more types as a polymer substance. In addition, an aqueous solution of poval is mixed and continuously dispersed, and those manufactured satisfying the specific gravity range of 1.03 to 1.04 can be mentioned. Moreover, in this invention, within the range which satisfies the said specific gravity characteristic, what is obtained by mixing a synthetic rubber latex and / or an acrylic polymer dispersion in said aqueous polymer dispersion can also be used.

  Use a mixture of finely divided solids (for example, inorganic substances such as silica, thermosetting resins such as epoxy and polyester, and thermoplastic resins having a high softening point) in aqueous polymer dispersions. can do.

  As an aqueous solution of poval, when the specific gravity is satisfied and injected into the back surface of the concrete structure, even if it is a vertical wall surface, the degree of polymerization is 300 to 3, It is preferably an aqueous solution of partially saponified poval having a viscosity of 000, preferably 500 to 2,000, and a saponification degree of 70 to 98, preferably 80 to 90. The concentration of the poval is preferably about 10% by weight from the viewpoint of workability and production of a highly concentrated dispersion, and such a concentration can be produced in several minutes, which is preferable in terms of shortening the production time.

  The addition amount of the poval aqueous solution is 0.5 to 10% with respect to the raw material made of the polymer substance in consideration of the viscosity appropriateness, the diffusibility after the injection, the water resistance, etc. As), more preferably 1 to 3%.

  In addition, an emulsion can be produced simply by using an aqueous poval solution as an emulsifier, but it is preferable to use a surfactant in order to make the particle size of the emulsion smaller and homogenized. As the surfactant, any of cationic, anionic and nonionic surfactants can be used. The amount of the surfactant added depends on the type, but is preferably 0.01 to 5% (based on the polymer material and the surfactant as a solid content) with respect to the polymer material.

  In the case of using a surfactant, it is preferable to use a combination of an anionic type and a nonionic type, and a preferable addition amount is to mix 2% anionic type and 0.3% nonionic type.

  The equipment for mixing the polymer substance and the poval aqueous solution is not particularly limited, and various kneaders, mills, and the like can be used.

  The water stopping agent used in the present invention preferably has a particle size of 0.4 to 0.6 μm. This is because even when injected into the back surface of the vertical wall surface of the concrete structure, it can be diffused better upward.

  The small particle size makes it easy to backflow and penetrate into the gaps in the fine water leakage path on the back of the concrete structure, and also closes the water leakage path more efficiently and reliably by adhering well to the concrete inside the water leakage location. The effect which can be done is acquired.

  In addition, since the cement slurry-like water stopping agent has a large particle size of 3.0 μm or more, it does not have good diffusibility with water existing on the back surface of the concrete structure, and is difficult to penetrate into the water leakage path. Adhesive strength is also small. Moreover, since the water blocking film is hard and brittle, there is a problem that it cannot follow the movement of the structure.

  In the present invention, a method of adding and mixing 3 to 5% by weight of an isocyanate prepolymer as a curing accelerator for the aqueous polymer dispersion is desirable with respect to the aqueous polymer dispersion. In this method, the specific gravity characteristics are satisfied, and the particle diameter falls within the range of 0.4 to 0.6 μm.

  The curing time is affected by the temperature of the back surface, and when 5% of a curing accelerator is added, it cures in water at 5 ° C. for 24 hours and at 30 ° C. for 4 hours to form a water stop film.

  In addition to the above, as a hardening accelerator, there is also a method of adding and mixing 5 to 10% by weight of cement slurry. In this method, the specific gravity is increased, the diffusibility is lowered, the particle diameter is also coarsened, and fine voids cannot be filled or closed. Furthermore, the curing time requires 24 hours even at 20 ° C., which is not practical.

In the present invention, since the specific gravity of the water-stopping agent is close to that of water, even if it is a vertical wall surface, it can diffuse thinly and form a water-stopping film over a wide range without sinking downward, thus reducing the amount used. be able to. This is because the water stoppage range in one injection hole is large. In the present invention, the injection amount per one injection hole is preferably 6 to 10 kg / m ^2, and the amount used when a conventional cement slurry-like water-stopping agent is used (super rock method) (15 to 20 kg / m ² ) is less than half.

  In the present invention, when the amount of water leakage from the concrete structure and the discharge pressure of the water leakage are abnormally large, the injected water-stopping agent may be pushed out in a short time. Inject foamed urethane resin in advance to reduce the amount of water discharged, or immediately after injecting the water-stopping agent, foam urethane resin is injected to significantly shorten the curing time. Extrusion can be suppressed.

  Hereinafter, the present invention will be described in more detail by way of examples.

Example 1
<Physical properties of aqueous polymer dispersion>
1. Specific gravity An “alpha sol G” manufactured by Sansei Chemical Co., Ltd. is used as an aqueous polymer dispersion which is a water-stopping agent used in the present invention. The specific gravity of this aqueous polymer dispersion was measured using a hydrometer. The results are shown in Table 1.

Specific gravity measurement of aqueous polymer dispersion added with 5% curing agent Add 50g curing agent and 50g water to 1kg of "Alpha Sol G", stir for 60 seconds with electric stirrer, After putting the whole amount into the graduated cylinder, the specific gravity was measured with a hydrometer. The results are shown in Table 1.

  Regarding the comparative water-stopping agent “Vitogrout” (also referred to as Nallite), the specific gravity of “Vitogrout” alone, the specific gravity of “Vitogrout” added with 5% of the same curing agent as in (2) above, and the result Is shown in Table 1.

  From Table 1 above, only the alpha sol G and the curing agent-added alpha sol G satisfy the specific gravity range of 1.03 to 1.04 of the present invention.

  On the other hand, only the commercially available bite grout and the hardener-added bit grout do not satisfy the specific gravity range of the present invention, and cannot be used as the water-stopping agent of the present invention.

2. pH
Alpha sol G: pH 7.0 to 7.5
Vito grout: pH 4.7-5.7

  The water-stopping agent contains a curing accelerator, but this curing accelerator has a neutralizing action, and can be neutralized if added in a large amount to the bit grout. However, if the amount added is small or varies, it becomes acidic, and if it enters into the back surface or cracks of concrete, there is a drawback of causing early deterioration of the concrete, so it cannot be used in the present invention.

  On the other hand, alpha sol G used in the present invention has a pH of 7.0 to 7.5 and is excellent in that it does not have the above problem.

Example 2
1 to 3 show the state of an injection and diffusion confirmation test using such an aqueous polymer dispersion having a specific gravity of 1.03 to 1.04.

The test apparatus was configured by fixing a transparent acrylic plate (thickness 10 mm) as a vertical wall surface to the side surface of the concrete U-shaped groove with a metal rod so that there was no harassment. The test apparatus was filled with compacted earth and sand, and water was immersed until the entire earth and sand became wet. An injection hole is drilled in the center of the lower part of the acrylic plate, a plug is attached to the injection hole, and an aqueous polymer dispersion (“Alpha Sol G” manufactured by Sansei Chemical Co., Ltd., specific gravity 1 is used using a high-pressure injection pump). 0.03) (injection amount: 10 kg / m ² ).

  The acrylic plate is provided with concentric scales at intervals of 10 cm with the injection hole as the center for confirmation of the diffusion condition (FIG. 1).

  Most of the water-stopper that has just penetrated between the back of the acrylic plate and the earth and sand from the outlet of the injection hole (shown in white in the figure) does not settle downward, but mostly follows the back of the acrylic plate. Thus, it diffused radially upward (FIG. 2).

  Thereafter, when the predetermined amount of water-stopping agent has been injected, the water-stopping agent diffuses radially around the outlet of the injection hole, and forms a water-stopping film over a wide area along the back surface of the acrylic plate. Formed (FIG. 3).

  In this way, by using a water-stopping agent composed of an aqueous polymer dispersion having a specific gravity of 1.03 to 1.04, even if it is a vertical wall surface, it is diffused radially upward around the outlet of the injection hole. It can be seen that the waterproof film can be formed over a wide range without being localized.

Example 3
FIG. 4 shows a specific application example of the back surface injection water stop method according to the present invention. FIG. 4 shows an example in which the back surface injection water stop method according to the present invention is applied as a countermeasure against water leakage in a tunnel, and shows a cross-sectional view when a water stop agent is injected into the back surface of a tunnel wall surface. In the figure, 1 is a tunnel, 2 is a tunnel wall surface which is a concrete structure, 3 is soil in contact with the back surface of the tunnel wall surface 2 (opposite surface of the tunnel 1), and water exists between the back surface of the tunnel wall surface 2 There is also a portion having a gap 4 that is open.

  As the injection holes 5, through holes having a diameter of about 10 mm that completely penetrate the tunnel wall surface 2 were formed in the tunnel wall surface 2 at a pitch of 1000 mm. When a plug (not shown) is attached to the injection hole 5 and the above-described water-stopping agent is injected by a high-pressure injection pump, the water-stopping agent is injected into the water in the gap 4 on the back surface of the tunnel wall surface 2. Since the water in the gap 4 is evenly pressurized on the tunnel wall 2, the water-stopping agent diffuses radially along the tunnel wall 2 and does not settle downward on the back of the vertical wall. Further, the water blocking film 6 having a predetermined thickness can be formed over a wide range of the back surface of the tunnel wall surface 2, and efficient and reliable water blocking can be performed.

1: Tunnel 2: Tunnel wall surface 3: Earth 4: Air gap 5: Injection hole 6: Water blocking film

Claims (2)

Providing an injection hole penetrating from the surface of the concrete structure toward the back surface;
Injecting a water-stopper into the injection hole;
In the back-side water-stopping construction method, comprising a step of forming a water-stopping film obtained by curing the water-stopping agent between the back surface of the concrete structure and the covered soil in contact with the back surface,
The water stopping agent used in the step of injecting the water stopping agent includes at least an aqueous polymer dispersion and a curing accelerator, and the specific gravity of the water stopping agent is 1.03 to 1.04.
The back surface injection water stop method is characterized in that the step of forming the water stop film diffuses and hardens radially along the back surface centering on the outlet of the injection hole.   The step of forming the water blocking film diffuses radially on the back surface of the vertical wall of the concrete structure, centering on the outlet of the injection hole, and along the back surface, and upward diffusion than the area of the lower diffusion region The back-surface injection water-stop method according to claim 1, wherein the area is diffused and hardened so that the area of the region increases.