JPH0880518A - Inside loading filling material and inside loading filling method - Google Patents

Abstract

PURPOSE: To contrive manufacturing of an inside loading filling material facilitating long distance pressure feed, by a method wherein a specific solution produced by mixing up a mixture of cement and fly ash taken as a curing material, a retarder, a thickening agent and water with one another and a specific solution of an aqueous solution of sodium silicate are mixed up with each other by pressure-feeding up to an operating place. CONSTITUTION: A 0.1-0.5wt.% retarder, 0.01-1.5wt.% thickening agent and at least 80wt.% water mixed up with a curing material produced by mixing up cement and fly ash with each other at a weight ratio of 7:3-3:7 are taken as a solution (A). A solution (B) comprised of an aqueous solution of sodium silicate mixed up with the solution (A) at a weight ratio of solution (A):solution (B)=95:5-80:20 is taken as an inside loading filling material. On the occasion of operation, the solution (A) and solution (B) are pressure-fed separately. Since both the solutions have a high fluidity, long distance pressure feed is possible. When both the solutions are mixed up with each other at the tip part of a pressure feed pipe, a calcium ion of the cement within the solution (A) and a silicate ion of the sodium silicate within the solution (B) react on each other and gel rapidly, hardened in a short time and strength is revealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filling material and a filling method.

[0002]

2. Description of the Related Art A filling material is a filling material which is partially or wholly filled in the hollow of an underground structure, and a construction method using this is a filling material filling method. For example, in the secondary construction of the shield method, what is filled to fix the water pipes, sewer pipes, etc. in the shield tunnel as shown in FIG.
That method is the filling method. The conventional method of secondary filling of shield tunnels is to fill the inside of the tunnel with a concrete pump from a casting base at the end of the tunnel, using fresh concrete as a filling material through a pressure-feeding pipe. , The method of filling is done. In FIG. 1, 11 is a segment, 12 is fresh concrete, and 13 is a water pipe.

However, since the fresh concrete has poor fluidity, the pressure of the concrete pump is 80 kg / c.
Since a high pressure of m ² or more is required, it is often dangerous. Further, it is pointed out that since the pressure is fed at a high pressure, the inside of the pressure feeding pipe is damaged, the pump is stopped, or the quality of the ready-mixed concrete is varied accordingly.
In addition, the pumping distance is very difficult to pump over a long distance of 1000 m or more, and the pumping of fresh concrete is limited to several tens of meters per day, which requires a considerable amount of time.
Furthermore, after pouring the ready-mixed concrete, it is necessary to wash the inside of the pumping pipe with water, so that it is necessary to secure a large amount of water, and a water tank facility, etc. is required in the pouring base facility.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an infill filling material and an infill filling method, which facilitates long-distance pressure-feeding, as an alternative to conventional concrete which is a conventional infill filling material.

[0005]

In order to achieve this object, the inventors of the present invention have, as a result of various studies, mixed a hardening agent consisting of a mixture of cement and fly ash, a thickener, a retarder and water. By separately pumping the liquid A and the liquid B composed of a sodium silicate aqueous solution, both liquids can be pumped at a low pressure, and thus the pumping distance can be lengthened.
It was found that a good filling filler can be obtained by mixing both liquids at the filling point, and the present invention was completed.

That is, the present invention comprises a mixture of a hardening agent made of a mixture of cement and fly ash, a retarder, a thickener, and water, and a solution B made of an aqueous solution of sodium silicate. 0.1 to 0.5% by weight of a retarder and a thickening agent with respect to a filling material (claim 1), a hardening material obtained by mixing cement and fly ash in a weight ratio of 7: 3 to 3: 7. A solution in which 0.01 to 1.5% by weight of the agent and 80% by weight or more of water are mixed, and B solution consisting of an aqueous solution of sodium silicate are
Liquid: B liquid = 95: 5 to 80: 20 mixed in a weight ratio of claim 1 infill filler (claim 2), shield tunnel secondary construction infill filler. Alternatively, the filling agent according to claim 2 (claim 3), a liquid A in which a hardening material made of a mixture of cement and fly ash, a retarder, a thickener and water are mixed, and a liquid B made of an aqueous solution of sodium silicate. Is sent under pressure to the filling point, and the two liquids are mixed together. (Claim 4) A hardening agent consisting of a mixture of cement and fly ash, a retarder, a thickener, and water are mixed. Liquid A and liquid B consisting of an aqueous solution of sodium silicate are pressure-fed to a filling point, both liquids are mixed and filled in, and then cement mortar is applied to the upper surface of the in-fill cured body. Filling and filling method (claim 5), cement and flyer 0.1% to 0.5% by weight of a retarder and 0.01% to 1.5% by weight of a thickener, with respect to a hardening material in which a weight ratio of 7: 3 to 3: 7 is mixed. Liquid A mixed with 80% by weight or more of water and liquid B composed of an aqueous solution of sodium silicate are pressure-fed to a filling point at a weight ratio of liquid A: liquid B = 95: 5 to 80:20 to mix both liquids. Claim 4 or 5 filling method (Claim 6), cement mortar is applied to a thickness of 5 mm or more, filling method (Claim 7), and secondary construction of a shield tunnel. The fill-in filling method according to any one of claims 4 to 7, which is a fill-in filling method.

The present invention will be described in detail below. The liquid A is a mixture of a hardening material composed of a mixture of cement and fly ash, a retarder, a thickener, and water. Here, examples of the cement in the hardened material include normal, early strength, super early strength, moderate heat Portland cement, and mixed cement such as blast furnace and fly ash cement. As the fly ash, either JIS standard products or non-standard products can be used, but it is preferable to use JIS standard products. The mixing ratio of cement and fly ash is not particularly limited, but from the viewpoint of fluidity, material separation, strength, etc., the mixing ratio of cement and fly ash is 7: 3 to 3: 7 by weight. Is preferred.

Examples of the retarder include gluconic acid-based, oxycarboxylic acid-based, and organic phosphoric acid-based retarders for cement. The retarder is 0.1 to 0.
It is preferable to add 5% by weight.

As the thickener, an organic type such as a cellulose type, an amide type, a biopolymer type or an inorganic type thickener such as bentonite can be used, but the addition amount of the organic type can be reduced. Therefore, it is preferable to use an organic thickener. The thickener is 0.01 to the curing material.
It is preferable to add 1.5% by weight.

From the viewpoint of strength and fluidity, the amount of water is preferably 80% by weight or more with respect to the hardened material.
If the content exceeds 8% by weight, material separation may occur.
It is more preferable to set it to 0 to 200% by weight.

It is preferable to use the aqueous solution of sodium silicate of the liquid B having a concentration of sodium silicate of 5 to 30%.

The mixing ratio of liquid A and liquid B is 9 by weight.
It is good to set it to 5: 5 to 80:20.

Next, the filling method for filling the inside will be described.
Since the liquids A and B show good fluidity,
Even a pressure-feeding pipe having a length of 1000 m or more can be easily pressure-fed separately to the filling point. As the pressure-feeding pipe is often provided with a back-filling pressure-feeding pipe at the time of construction in the shield construction method, this pressure-feeding pipe can be used. By mixing solution A and solution B at the tip of the pressure-feeding pipe, the solution is rapidly set in a few seconds to a few tens of seconds, and a strength of 1 kgf / cm ² is developed for 1 hour. Construction is possible and construction time can be greatly reduced.

Furthermore, 5 m on the upper surface of the embedding cured product.
By applying a cement mortar of m or more, it is possible to suppress the drying of the infill-cured product and prevent the strength from decreasing due to drying shrinkage. The coating thickness of the cement mortar is preferably 5 mm or more, more preferably 5 to 100 mm. A cross section of the shield thus constructed is shown in FIG. In FIG. 2, 21 is a segment, 22
Is the filling material of the present invention, 23 is a water pipe, and 24 is cement mortar.

[0015]

The cement in the hardening material in the liquid A is hardened by a hydration reaction and exhibits strength. Fly ash is a posolan active substance that reacts with cement hydrate (pozzolan reaction) to increase long-term strength. Further, fly ash is filled in the voids of the cement particles, and because the cement has a zeta potential, it aggregates with the fly ash particles to increase the density and reduce the material separation. The retarder is a substance having an electric potential and adheres to the surface of cement particles to delay the hydration reaction. Control the reaction time of cement by adjusting the amount of retarder,
Pot life can be extended. The thickening agent is a viscosity-increasing agent and reduces the material separation of the mixture of liquid A and liquid B.

Since the liquids A and B have high fluidity, they can be pressure-fed over a long distance. In addition, by mixing the liquids A and B, the calcium ions of the cement in the liquid A and the silicate ions of sodium silicate in the liquid B rapidly react, gel, harden in a short time, and develop strength. To do.

After mixing the liquids A and B and curing them,
When cured in the air, cracks may occur due to drying shrinkage, which may reduce the strength of the infill cured product. Therefore, if curing is performed in a non-dried state, it is possible to suppress the occurrence of cracks and suppress the decrease in strength. If cement mortar is applied to the upper surface of the infill-cured product, drying shrinkage can be prevented, thereby suppressing the occurrence of cracks and ensuring strength.

[0018]

EXAMPLES The present invention will be further described below based on examples. The materials used in this example are shown in Table 1.

[0019]

[Table 1]

(Example 1) A retarder and a thickener were mixed with water, and a mixture of cement and fly ash, which had been mixed in advance, was added to this solution and mixed for 2 minutes to prepare a liquid A.
In order to investigate the optimum blending ratio of the liquid A, the liquid was blended according to Table 2 and the flow value was measured for this liquid.

[0021]

[Table 2]

FIG. 3 shows the weight ratio of cement (C) and fly ash (FA) (C:
It shows the relationship between water / (cement + fly ash) = W / (C + FA) and the flow value when the FA ratio) is changed. From FIG. 3, when the W / (C + FA) ratio was 80% by weight or more, all flow values exceeded 40 cm regardless of the C: FA ratio. Since the larger the flow value, the higher the fluidity, it was found that the water / curing material ratio of 80% by weight or more shows good fluidity. Therefore, the water / curing material ratio may be 80% by weight or more, but if it exceeds 200% by weight, material separation may occur, so 80 to 200% by weight is preferable. In addition, when the weight ratio of cement and fly ash was 10: 0, that is, in the case of cement alone, remarkable floating water was observed, and it was confirmed that material separation occurs. Further, when the weight ratio of cement and fly ash is 0:10, that is, when the fly ash is alone, it does not cure even when mixed with the liquid B. Therefore, the mixing ratio of cement and fly ash may be any ratio, but cement: fly ash = 3: 7 to 7: 3 is preferable.

In order to examine the optimum amount of the retarder added, the compounds were blended according to Table 3 and the pot life of solution A was measured.

[0024]

[Table 3]

Table 4 shows the measurement results of the pot life. If the amount of the retarder added is 0.05% or less, the solution A will be cured after 8 hours, and it will not be possible to mix and fill the solution B with the filler. However, it can be seen that when 0.1% is added, it can be used after 24 hours. It should be noted that a pot life of more than one week is not required for the construction, and therefore it is preferable to add the retarder in an amount of 0.1 to 0.5% by weight based on the hardening material.

[0026]

[Table 4]

When the thickener is added in an amount of less than 0.01% by weight with respect to the hardener, the liquid A undergoes significant material separation and cannot serve as a thickener. On the other hand, if the amount added exceeds 1.5% by weight, the viscosity of the liquid A becomes high and the pumpability becomes poor. Therefore, the thickener is 0.01 to
It is preferable to add 1.5% by weight.

(Example 2) A mixture of a retarder and a thickener, mixed with cement and fly ash, was used as solution A, and solution B composed of an aqueous solution of sodium silicate was mixed with an inner diameter of 50 mm. It was put in a mold having a height of 200 mm.
Then, 10m of cement mortar (water: cement: standard sand = 1: 0.65: 1) is placed on top of the filler inside the mold.
It was applied to a thickness of m and cured with mortar for a predetermined time. After curing for a predetermined time, remove the sample from the mold and set the diameter to 5
A specimen having a size of 0 mm and a height of 100 mm was obtained. A uniaxial compressive strength test was performed on the obtained specimen. Table 5 shows the composition of the solutions A and B. For comparison, after the mixture of the liquid A and the liquid B was filled in the same mold as described above, the mold was removed, and a specimen having a diameter of 50 mm and a height of 100 mm was taken out. After subjecting each of the specimens to water-curing, air-curing and wet-curing at 20 ° C., a uniaxial compressive strength test was conducted.

[0029]

[Table 5]

The results of the uniaxial compressive strength test are shown in FIG. The 1-hour strength shows a value of around 3 gf / cm ² under all curing conditions, and it can be seen that the work after filling can be performed after 1 hour or more. The strength after 1 day is 30 kgf / cm.
² , the increase in strength was observed. It can be seen that the air-cured specimen cracked after 7 days and a clear decrease in strength had occurred. However, under three types of curing conditions: mortar curing, underwater curing and wet curing, 70 kg in 7 days
The strength of mortar curing is slightly reduced around f / cm ^{2 and} after 28 days, but the strength is increased under any curing condition.
However, underwater curing is not possible with on-site construction. On the other hand, although wet curing is a good curing method, it cannot be said to be a reliable curing method in the field, so the mortar curing method in which cement mortar is applied to the upper part is most suitable.

Example 3 In a shield tunnel having an inner diameter of 3 m, a filling material having the composition shown in Table 5 was filled, and cement mortar was applied to the upper surface of the hardened filling material. Two pipes (both having an inner diameter of 5 cm) for the liquid A and the liquid B were used as the pressure-feeding pipe for pressure-feeding the filling part. As a result of the pressure-feeding, the pressure-feeding was 8 kg / cm ² without any problem even at a distance of 2000 m, and the inside of the pressure-feeding pipe was not closed even after one week of construction. When cement mortar was applied to the upper surface of the hardened body and cured for 3 days, no cracks were found and the work on the hardened cement mortar could be performed without any problems. The cement mortar applied with a thickness of less than 5 mm was cracked because the strength of the cement mortar was weak when working on the upper surface, so the application thickness of the cement mortar was 5 m.
It is good to be more than m.

[0032]

As described above, the infill filling method using the infill filler of the present invention has extremely high fluidity, so that pumping can be facilitated and long-distance feeding is possible.
Further, since the strength is manifested at an early stage, the construction time can be shortened as compared with the conventional filling method using the ready-mixed concrete. Further, since the potting filler of the present invention has a long pot life, the inside of the pressure feeding pipe will not be closed even during an emergency stop during pressure feeding.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a conventional shield tunnel after being filled with a ready-mixed concrete as a filling material.

FIG. 2 is a cross-sectional view of a shield tunnel using the filling filler of the present invention after being filled.

FIG. 3 shows C: FA for the composition of the liquid A in Table 2 of Example 1.
It is a figure which shows the relationship between W / (C + FA) and a flow value when changing.

FIG. 4 is a diagram showing the relationship between the number of curing days and the uniaxial compressive strength when cured under four types of curing conditions of Example 2.

[Explanation of symbols]

 11 segment 12 ready-mixed concrete 13 water pipe 21 segment 22 filling material of the present invention 23 water pipe 24 cement mortar

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C04B 24:38) 24:04 103: 44

Claims (8)

[Claims] 1. An embedding filler comprising a mixture of a hardening agent made of a mixture of cement and fly ash, a retarder, a thickener and water, and a solution B made of an aqueous solution of sodium silicate. . 2. A retarder is 0.1 to 0.5% by weight, and a thickener is 0.1% to a hardener in which cement and fly ash are mixed in a weight ratio of 7: 3 to 3: 7. Solution A, in which 01 to 1.5% by weight and 80% by weight or more of water are mixed, and solution B consisting of an aqueous solution of sodium silicate, are prepared as solution A: solution B = 95: 5 to 80:
The fill filler according to claim 1, which is mixed in a weight ratio of 20. 3. The infill filler according to claim 1, which is an infill filler for secondary construction of a shield tunnel. 4. A liquid A in which a hardening agent made of a mixture of cement and fly ash, a retarder, a thickener, and water are mixed, and a liquid B made of an aqueous solution of sodium silicate is pressure-fed to a filling point, and both liquids An infill filling method, characterized in that: 5. Liquid A, which is a mixture of a cement and fly ash, containing a hardening agent, a retarder, a thickener, and water, and a liquid B, which is an aqueous solution of sodium silicate, are pressure-fed to the filling point, and both liquids A filling method for filling a filling, characterized by mixing and filling the mixture, and then applying cement mortar to the upper surface of the cured filling material. 6. A retarder is 0.1 to 0.5% by weight, and a thickener is 0.1% to a hardener obtained by mixing cement and fly ash in a weight ratio of 7: 3 to 3: 7. A liquid in which 01 to 1.5% by weight and 80% by weight or more of water are mixed, and a B liquid which is an aqueous solution of sodium silicate are A liquid: B liquid = 95: 5 to 8
The infill filling method according to claim 4 or 5, wherein the both liquids are mixed by pumping to a filling portion at a weight ratio of 0:20. 7. The filling method according to claim 5, wherein the cement mortar is applied to a thickness of 5 mm or more. 8. The infill filling method according to claim 4, wherein the infill filling method is a secondary construction of a shield tunnel.