JP2887169B2 - Crack injection waterproofing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of injecting a water-stopping agent into cracks for repairing water leakage from cracks generated in underground concrete structures or the like, thereby stopping water. About.

[Conventional technology]

For example, underground concrete structures such as road tunnels, subways, underground shopping malls, and underground passages are increasing year by year with the development of underground spaces.

In recent years, with the overcrowding of ground use in cities and the like, a deep underground development concept has been proposed.

In general, underground structures are generally constructed below the groundwater level, and there is a problem of leakage of groundwater as a problem in maintenance of old underground structures.

This leakage is due to cracks, etc., occurring in the concrete members of the underground structure. The causes of the cracks include not only excessive stress, but also deterioration of the concrete due to neutralization of the concrete, alkali-aggregate reaction, and the effect of acids in the groundwater. Or, an external force generated abnormally due to an earthquake or the like.

The generation of cracks can be prevented to some extent during the design and construction of concrete structures by reducing the generated stress or taking into account concrete mixing, but it cannot be completely prevented. Therefore, development of an effective crack repair method is desired.

Conventionally, crack repair methods for concrete members of underground structures mainly include backfill injection methods and crack injection methods.

In the former backfill injection method, as shown in FIG. 5, an injection pipe provided in an injection hole 52 formed through a concrete member 50 at a crack 51 generated in the concrete member 50.
The backfill 53 is usually filled with a chemical liquid backing agent 54 over a fairly wide range, and the backfill 54 reinforces the concrete part 50 and the back of the crack 51 (the back of the concrete member). This is a method of stopping water by covering with water.

On the other hand, the latter crack injection method is shown in FIGS.
As shown in the figure, a V cut 55 is made along the water leak crack 51, and then an injection pipe 56 is attached at a predetermined interval so that the water leak crack 51 is injected, and the V cut 55 is formed. Is sealed with a waterproof cement 57 made of quick-setting cement or the like, and then a waterproofing agent is injected from the injection pipe 56.

Further, the water stopping cement 57 closes the water stopping agent injected by the injection pipe 56 so as not to flow backward from the crack portion, and functions as a filling water stopping agent after the completion of the construction.

On the other hand, as the water stopping agent in the crack injection method, there are various types such as an inorganic type and an organic type such as an epoxy type or a urethane type. As described above, a 1.5-shot method is used in which a main agent and a curing agent are mixed and injected in the middle using a Y-shaped injection pipe. In this method, an injection time of 3 to 3 hours is required to penetrate deep into the crack.
A water-stopping agent is required for about 5 hours, and a water-stopping agent having a curing time as long as that is used.

[Problems to be solved by the invention]

However, it is impossible or extremely difficult to completely prevent the leakage of groundwater by the conventional crack repair method.

Specifically, in the case of the former backfill injection method, especially when there is a flow of groundwater W, the backfill filler is swept away by the flow of the groundwater W and escapes into the ground. As described above, it is difficult to reliably cover the entire back surface of the portion where the crack 51 is generated, and a portion that is not covered with the backfilling agent is generated, and water leakage may occur therefrom. Furthermore, in order to avoid such a situation as much as possible, in the conventional method, a large amount of backfilling agent is used, which not only increases the agent cost, but also often causes disturbance of the groundwater flow. There is a problem that it adversely affects the location.

In the case of the latter crack injection method,
Injecting the injectant from the former side under the idea that 51 will not be spread as much as possible, and it is necessary to inject for a long time at low pressure. For this reason, it takes a long time to complete the construction, and it is difficult to sufficiently inject the waterproofing agent into the deep part of the crack 51. In particular, in the case of a thin crack, it is impossible to completely stop the waterproofing. Was.

When importance is placed on permeability, a cement-based water-stopping agent cannot be used, and a resin-based water-stopping agent must be used. Resin waterproofing agents have disadvantages such as high cost, poor compatibility with concrete members, and the need for long-term repair.

Therefore, an object of the present invention is to provide a water stopping method capable of completely closing a crack or the like generated in an underground structure with a water stopping agent and completely blocking water leakage due to groundwater.

[Means for solving the problem]

The present invention that has solved the above-mentioned problems provides an injection for injecting a water blocking agent that penetrates a concrete member from the front to the back into a crack or a vicinity of the crack generated by communicating inside and outside with a concrete member of an underground concrete structure. A hole is formed, and in a state where the injection pipe reaches the rear of the concrete member or protrudes through the injection hole, a two-liquid curing type quick setting hardening backfill filler is injected into the rear of the concrete member through the injection pipe to form a concrete. After forming a cured body covering the crack opening on the back surface of the member, insert the injection pipe into the injection hole or another injection hole formed in the crack portion, and in a state where the discharge port of the injection pipe faces the crack. A crack injection water-stopping method characterized by injecting an injectant for injecting a permeable crack into a crack.

[Action]

In the present invention, first, a flash-setting curable backfill filler is injected into the back of the concrete structure from the injection hole. This covers the back of the concrete structure. If this back cover is sufficient, water leakage can be prevented,
As mentioned above, the reliability is poor. In addition, from the viewpoint of the water stopping effect, it is ideal that the water stopping agent is injected into the crack, so that the instantaneously hardening backfill injection is an auxiliary means.

Therefore, in the present invention, an injection tube is inserted into an injection hole formed in a crack or an injection hole formed as necessary so as to intersect with the crack, and the discharge port is exposed to the crack, and the permeable material is introduced into the crack. A good crack injection injectant is to be injected. At the time of injecting this crack injection filler, the back side of the concrete structure
Since the cured product of the instantaneously curable backfill injecting agent has already been formed and covered, the injected cracking injectant penetrates into the cracks, hardens, and water is stopped.

[Specific configuration of the invention]

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 to 3 show a first embodiment, wherein FIGS. 1 and 3 are longitudinal sectional views along cracks, and FIG. 2 is a view from the back side of a concrete structure. .

When a crack 2 is generated in the concrete member 1, an injection hole 3 is formed in the crack 2 or in the vicinity thereof by a hammer drill or the like. Next, a discharge port 4A is formed at the distal end, and an injection pipe 4 provided with a packer 4B on the base side thereof is inserted into the injection hole 3.

At this time, the discharge port 4A of the injection pipe 4 is connected to the concrete member 1
Has reached the back of the camera or is in a protruding state.

In this state, the injection pipe 4 is filled with a flash-setting curable backfilling agent,
For example, a two-part curable injectant 5 of A liquid and B liquid is injected into the back surface of the concrete member 1. By this flash-setting curable backfill injection, a cured body M covering the back surface of the crack 2 is formed.

When the flash-setting backfill injection is completed, the injection pipe 4 is retracted as shown in FIG.
, And the crack injection material 6 having good permeability is injected into the crack 2. Injection 6 injected
Is penetrated exclusively into the crack 2 because the front is covered with the cured body M.

In this crack injection, when outflow of the injectant 6 is seen from the front surface of the concrete member 1, it can be determined that the injectant 6 has been filled in the crack 2.

As the injection tube 4 in the present invention, an appropriate one such as a single tube, a 1.5 shot tube, or a double tube can be used.

As the quick-setting curable backfill filler, a quick-setting curable filler can be preferably used. To prevent runaway of the infusate due to groundwater flow, the gel time should be within 5 minutes, more preferably within 1 minute, especially within 30 seconds. The two-pack type, preferably a cement type or a water glass type, is preferable as the injection agent for this purpose. On the other hand, as the injection agent for crack injection, there is no limitation on the gel time, and a cement-based injection agent is preferable in terms of durability and familiarity with concrete. When the highest priority is given to permeability, a water glass-based material can be used. Other fillers for crack injection that can be used in the method of the present invention include natural rubber latex: styrene-butanediene rubber (SB
R), synthetic rubber latex such as nitrile-butanediene rubber (NBR), chloroprene, methyl methacrylate-butanediene rubber: acrylate, vinyl acetate, ethylene-vinyl acetate copolymer, vinylidene chloride
Various aqueous polymer dispersions such as synthetic resin emulsions such as vinyl chloride copolymer type: unsaturated polyester type, epoxy type, polyurethane type, tar epoxy type, tar urethane type, epoxy asphalt type, rubber asphalt type, fluororesin type Various liquid or paste resins such as: styrene, acrylonitrile, styrene-acrylonitrile, vinyl chloride, vinyl acetate, methacrylate, diallyl phthalate, trimethylolpropane trimethacrylate, epoxy styrene,
Various concrete impregnating monomers or polymers such as acrylamide, N-methylolacrylamide, polyethylene glycol dimethacrylate, siliconates such as methylsiliconate, modified alkylsiliconate, and silicon-based compounds such as silane compounds, methylsilicon, and modified alkylsilicon. A rust preventive for reinforcing steel, a surfactant, and the like, and one or more of these can be used.

In addition, in the method of the present invention, an inorganic or organic filler can be used as the backfill or crack injection filler, and the use of an epoxy or urethane filler is not excluded.

In order to prevent the injection agent for crack injection from flowing out of the gap between the outer periphery of the injection tube 4 and the injection hole 3 to the front side of the concrete member 1, it is preferable to attach the injection agent to the packer 4B on the injection tube 4. When the hardening time is long, the crack injecting agent injected into the crack 2 passes through the crack 2 of the concrete member 1 and bypasses the packer 4B via the injection hole 3 or the concrete. It may flow out to the front of the member 1. In this case, the outflow of the crack injection agent can be prevented by using a waterproof cement or the like at the entrance of the injection hole 3 or the front surface of the concrete member 1 from which the crack injection agent has flowed.

In the first embodiment, the flash-curing backfill injection is performed.
This is an example in which an injection hole 3 is formed in a crack 2 and also serves as an injection hole for injection of an injection agent 6 for crack injection. As another example, as shown in FIG. 4, when the backfill injection hole 3A is provided in the vicinity of the crack 2, the crack injection hole 3B is formed separately from the backfill injection hole 3A in the crack. Forming and filling agent 6
May be injected.

When the length of the crack 2 is long, the crack injection can be performed while forming a plurality of injection holes for crack injection along the crack 2.

〔The invention's effect〕

As described in detail above, according to the present invention, a liquid-curing quick-setting hardening backfill filler is used for backing the back surface of the concrete member, and a permeable crack injection filler is used for cracks. The combination can reliably inject the waterstop into the crack without water leakage.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an injection state of a flash-curing backfill filler according to a first embodiment of the present invention, FIG. 2 is a view from the back of the concrete structure, and FIG. FIG. 4 is a longitudinal sectional view showing an injection state of a crack injecting agent in one embodiment, FIG. 4 is a longitudinal sectional view of another embodiment, FIG. 5 is a longitudinal sectional view of a conventional backfill injection method, and FIG. FIG. 7 is a longitudinal sectional view of a conventional crack injection method, and FIG. 7 is a view from the front of a concrete structure. DESCRIPTION OF SYMBOLS 1 ... Concrete member, 2 ... Crack, 3 ... Injection hole, 4 ... Injection tube, 5 ... Backfilling injectant, 6 ... Crack injecting agent, M ... Hardened body

Claims (1)

(57) [Claims] An injection hole for injecting a water blocking agent that penetrates a concrete member from a front surface to a rear surface thereof is formed in a crack generated in communication with a concrete member of an underground concrete structure inside and outside or near the crack. With the injection pipe reaching the rear of the concrete member or protruding into the injection hole, a two-liquid curing type quick setting hardening backfill filler is injected into the rear of the concrete member through the injection pipe to crack the rear of the concrete member. After forming a cured body covering the opening, the permeable crack is inserted in a state where an injection pipe is inserted into the injection hole or another injection hole formed in the crack portion and the discharge port of the injection pipe faces the crack. A crack injection waterproofing method, characterized by injecting an injection agent and allowing it to penetrate into cracks.