JPH06228537A - Repairing grout for buried pipe - Google Patents

Abstract

PURPOSE:To obtain a grout having properties satisfying requirements as a repairing grout. CONSTITUTION:A repairing grout mainly comprises water glass, formaldehyde, glyoxal, a mixture of formaldehyde with glyoxal, and at least one water-sol. aminoplastic resin with urea as the nitrogen component. A gelation accelerator or tackifier is added as necessary to adjust the gelation time or tackiness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention mainly relates to a water pipe, a sewer pipe,
Existing buried pipes and waterways such as telephone line pipes, electric line pipes, gas pipes,
The present invention relates to grout material for the purpose of repairing water leaks and stopping water in existing tunnels (hereinafter collectively referred to as existing buried pipes) such as roads, or ensuring stability (reinforcement).

[0002]

2. Description of the Related Art Conventional grouts for repairing existing buried pipes have not been established yet, and generally, as backfilling grout (filling grout) used during construction, grout mainly composed of cement and clay is used. (Typically, cement-bentonite grout, CB grout) and ground injection chemicals (typically LW grout, LW grout) that combine cement and water glass are used for convenience. I'm just being told.

[0003]

[Problems to be Solved by the Invention] Generally, the properties required as a repair grout are 1) excellent durability, 2) excellent waterproofness, and 3) no shrinkage (volume change). , 4) Viscosity can be obtained according to the size of the repaired area and the size of the surrounding ground, 5) Possibility to inject a limited area (periphery of the existing pipe), 6) Poor water permeability, etc. .

However, the above-mentioned CB and LW grout have the following problems, respectively.

In CB grout, a) contraction of grout (generation of breathing) is very large in a flowable state required for injection, and b) setting time (hardening by hydration reaction of cement) is very long. The injected grout is diluted with groundwater, and the water quality is very poor. C) The water permeability is large. D) It is difficult to fill the limited range because it does not have the consolidation ability (gelling time) for a short time. You'll be escaping to unnecessary distances.

[0006] In LW grout, a) water resistance is inferior due to slight shrinkage, b) durability is poor, and c) material is separated by gelation because a large amount of cement is contained in the grout. As a result, uniform consolidation strength cannot be obtained, and it is impossible for the grout to permeate into the ground around the existing buried pipe (especially the ground with low water permeability such as sand layer).

As described above, each of the conventional CB and LW grout has a fatal problem, and the grout satisfying the necessary properties as the repair grout has not yet been developed.

[0008]

[Means for Solving the Problems] In order to obtain a grout satisfying the above conditions 1) to 6) required as a repair grout, the present invention comprises water glass, formaldehyde, glyoxal, formaldehyde and glyoxal. And a solution-type grout whose main component is a compound containing at least one type of water-soluble amino plastic resin whose nitrogen component is urea (hereinafter referred to as a gelling agent), and if necessary, an adhesive or It proposes a repair grout to which a gelling accelerator is added.

[0009]

[Function] The grout mainly composed of water glass and the gelling agent of the present invention has extremely excellent physical properties such as durability, non-shrinkability, water permeability and water stopping property, and further has a gelling ability (gel time Since it can be adjusted), a limited range of injection (filling) is possible.

Further, the viscosity of the grout can be adjusted depending on the intended repair location of the existing buried pipe and the size of the gap between the ground around the existing buried pipe, and the ground can be solidified including the ground around the pipe.

What is important in repairing an existing buried pipe is to adjust the viscosity of the grout adapted to the size of the portion to be repaired and the size of the ground gap.

For example, if grout having a low viscosity is injected and filled around a pipe or a place having a large gap in the ground, it cannot be filled in a desired place, and it escapes to an unnecessary place and cannot achieve the purpose. become.

Therefore, the physical properties of the grout of the present invention (the above-mentioned
In addition to 1) -4)), the target site can be effectively repaired only by combining gelling ability and viscosity.

[0014]

EXAMPLES The repair grout of the present invention comprises water glass, a compound containing at least one water-soluble amino plastic resin containing water, formaldehyde, glyoxal, a mixture of formaldehyde and glyoxal, and a nitrogen component consisting of urea. A solution type grout having a main component (hereinafter, referred to as a gelling agent) is optionally added with an adhesive or a gelling accelerator.

The water glass used in the present invention is not particularly limited, but usually a molar ratio of 2.5 to 3.0 or more is desirable.

The gelling time is determined by the amount of the gelling agent of the present invention, but it can be shortened by adding a gelling accelerator if necessary.

The gelling accelerator is not particularly limited, but among the conventional gelling accelerators for water glass, in the present invention, the addition of the gelling agent causes the grout to shrink. Cannot be used.

As an example of the gelation accelerator used in the present invention, a substance containing a calcium compound (calcium hydroxide) is preferable.

The pressure-sensitive adhesive used in the present invention is not particularly limited, but montmorillonite clay mineral is preferable.

The method of injecting the grout of the present invention is not particularly limited, but when the gelation time is long (20 to 30 minutes or more), the one-shot method (mixing the grout at once in the mixing tank, If the gelation time is short, 1.5 shot method (water glass as liquid A,
As a solution B, a gelling agent is used, and an adhesive and a gelation accelerator are added to either solution A or solution B), and these solutions A and B are separately prepared and pressure-fed by two pumps. There is a method of merging and injecting before the entrance, and injecting by either method.

When implanting by the 1.5 shot method,
The injection ratios of the liquid A and the liquid B are not particularly limited, but they are generally mixed in equal amounts or ratios.

In the following, more detailed description will be given with reference to examples by experiments. The water glass used in the experiments was JIS No. 3,
A mixture of formaldehyde and glyoxal as a gelling agent, powdered calcium hydroxide as a gelling accelerator,
Montmorillonite clay mineral (trade name, super clay) and cement were used as the adhesive.

"Experiment-I"

As properties of the repair grout, gelation time, consolidation strength, viscosity, shrinkage and water permeability were determined and Table 1
Got the result.

[0025]

[Table 1]

From Table 1, Comparative Example 1 has gelation ability but has large material separation and shrinkage (see Experiment II), and Comparative Example 2 has large breathing and large viscosity. Therefore, neither is suitable as a repair grout.

On the other hand, the grout of the present invention comprises water glass and a gelling agent as a basic composition (Examples 1, 2 and 3),
By combining this with a gelation accelerator (Examples 4 and 5) or a pressure-sensitive adhesive (Examples 6, 7, and 8), the gelation time and viscosity can be adjusted arbitrarily, and no material separation occurs in any grout. It can be seen that it is suitable as a repair grout that is non-shrinkable (see Experiment-II).

"Experiment-II"

In order to examine the most important property of the repair grout, the water-stopping property, the iron pipe having a diameter of 5 cm and a length of 100 cm was laid on its side and the length from the end to the length of 30 cm was compared with Comparative Examples 1 and 2 of Experiment-I.
After the grouts of Examples 3 and 6 were prepared, they were immediately filled without gaps (after filling, gels were formed in the pipes of Comparative Example 1 and Examples 3 and 6), and 1 day later, the cavity was filled with water.

As a result, the CB grout (Comparative Example 2) showed a large amount of water leakage, and the LW (Comparative Example 1) also showed water leakage.

On the other hand, no water leakage was observed in any of the grouts of the present invention, and it was found that the water resistance was very good.

"Experiment-III"

As a repair grout, a durability test was conducted to see whether the durability was good or bad, and the results shown in Table 2 were obtained.

[0034]

[Table 2]

Further, as a comparison with the example, a comparative example 1 in which the water stopping property was slightly good in Experiment-II was also performed.

Although a test method for durability of water glass has not been established yet, whether or not the grout excluding cement is durable when cured in water can be confirmed in 1 to 3 months. Therefore, here, the number of training days was set to 6 months for evaluation. From the results of Table 2, Comparative Example 1
Since the cement contains cement, the strength has increased up to 1 month, but the strength has decreased (deteriorated) as it is cured over a long period of time, and it has decreased by about 40% after 6 months, and the durability has decreased. Clearly there is a tendency to undermine.

On the other hand, although the grout of the present invention has a lower strength than that of Comparative Example 2, it has been found that the strength is stable without any decrease in the strength over a long period of time and the durability is not impaired. From this, it was confirmed that the grout of the present invention was excellent in durability.

"Experiment-IV"

An example of an experiment in which the repair grout 8 is injected (filled) using the actual-scale mold shown in FIG. 1 will be described.

As shown in FIG. 1, the experimental apparatus excavated the cohesive land 1 over a width of 2 m, a length of 3 m and a depth of 2 m, and
The earth and sand (fine sand and sand-mixed gravel) 4 in Table 3 is laid down to a thickness of 0.5 m, and the fume tube 2 (inner diameter 50 cm, length 1.2 m) is placed on it.
The main tube was placed, and a gap (1 mm and 5 mm) was provided between each of the fume tubes 2 and 2.

Earth and sand are laid on the top of the fume tube 2 to a depth of 0.5 m, a vinyl sheet 5 (to prevent the upper leak of the grout) is placed thereon, and the sand 1'is packed up to the top,
Further, a block (weight) 6 was placed on it.

Injection pipe 7 for injecting repair grout 8
Was installed so that the tip openings were located at the lower part and the upper part of the fume tube 2 for injection.

"Comparative Example-1"

When the grout was divided into A and B liquids, they were combined (1, 5 shot system) in front of the injection pipe, and 400 l was injected (filled) into the mold under the condition A at a discharge rate of 10 l per minute.
The pressure was 0.5 Kgf / cm2.

After pouring, after excavation, it was found that the pipe was filled with homogel and penetrated only a little into the earth and sand, and most of it ran in the earth and sand, and more to the field board. It was running away, and there was very little intrusion into the interior through the gap between the tubes.

When the same injection was performed using the mold under the condition B, the injection pressure was almost unchanged.

After the injection, when excavating, the lower part of the pipe and the space between the sediment below the pipe were filled with grout, but there was material separation, and the lower layer contained a large amount of cement and had a high consolidation strength. It was found that the upper layer had little cement and had very low strength.

On the other hand, the upper part of the pipe and the sediment on the pipe were hardly filled with grout. Also, a large amount of grout had entered through the gap between the pipes.

As described above, if the gap between the pipes becomes large, the surroundings of the pipe cannot be filled sufficiently, and the pipe will penetrate into the pipe.

On the other hand, if the ground gap around the pipe is small, grout cannot be filled between the soil particles, and conversely, if it is large, the surroundings of the pipe and the soil particles cannot be uniformly filled.

That is, it is not suitable as a repair grout under any conditions.

"Example-3"

In the mold of condition A, except that the method of injecting grout (one-shot method) was different, the same operation as in Comparative Example 1 was carried out. The injection pressure was about 0.5 Kgf / cm 2.

After pouring, after digging, the grout showed almost no escape to the field board, and the grouting was infiltrated and consolidated around the pipe, including the soil, and no homogel vein phenomenon was observed. Penetration from the gap between the tubes was also minimal.

"Example-7"

When the condition B mold was performed in the same manner as in Comparative Example 2, the injection pressure was 0.5 to 0.8 Kgf / cm 2.

After pouring, the material was dug and found to be uniformly filled around the pipe and in the gap between the soil and the material without causing material separation, and the intrusion of grout from the gap between the pipes was extremely small.

As described above, the grout of the present invention exerts an effect as a repair grout by adjusting the viscosity of the grout, the gel time, etc. according to the size of the target pipe gap and the size of the ground gap. You can

The grout of the present invention can also be used for ground injection for the purpose of non-shrinkage and durability and other fields.

[0060]

As described above, according to the present invention, the gelling time and the viscosity suitable for the size of the injection target site and the size of the gap can be arbitrarily adjusted, and the durability and the non-shrinkability (water stopping property) are satisfied. You can get a repair grout to do so.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an experimental apparatus according to the present invention.

[Explanation of symbols]

 1 Cohesive ground 1'Mountain sand 2 Fume pipe 3 Gap 4 Soil 5 Vinyl sheet 6 Weight 7 Injection pipe 8 Repair grout

[Table 3]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication C04B 22:06 Z 2102-4G 14:10) Z 2102-4G (72) Inventor Masao Seki Tokyo Within Minami-ku Moto-Akasaka 1-6-4 Chemical Grout Co., Ltd.

Claims (2)

[Claims] 1. A water-based glass, a formaldehyde, a glyoxal, a mixture of formaldehyde and glyoxal, and a compound containing at least one water-soluble aminoplastic resin whose nitrogen component is urea, as a main component, and if necessary. A grouting material for repairing an existing buried pipe, which is characterized by adding a gelation accelerator or an adhesive to adjust the gelation time and viscosity. 2. The repair grout material for an existing buried pipe according to claim 1, wherein the gelation accelerator is a substance containing calcium hydroxide.