JP2010018474A - Filler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filler having high fluidity even when fly ash is added. <P>SOLUTION: The filler is obtained by blending, by mass based on cement of 1, bentonite of 0.096-0.24 as a water holding agent, metal powder of 0.00025-0.001 as a foaming agent, lignin sulfonate of 0.002-0.01 as a fluidizing agent and sodium silicate of 0.005-0.015 as a hardening accelerating agent. The filler is filled between the tubes of a double tube structure as filler. In such a case, the water holding agent, the fluidizing agent, a hardening accelerating agent and the foaming agent are made powdery and are pre-mixed to make a fluidizing material a<SB>1</SB>, and a mixture a<SB>2</SB>of the fluidizing material a<SB>1</SB>with water (w) is mixed with a mixture a3 of cement (s), in which the fly ash is added, with water and stirred to make the filler. The incorporation of the hardening agent accelerates the hardening of the filler and then, even when the fly ash is added in the filler, the delay of the hardening hardly occurs and the increase of bleeding and the reduction of the volume hardly occur. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  This invention is filled with a void filling material used for filling voids such as water and sewage pipes, piping by a shield method, waste pipes, and other crust voids, a filling method therefor, and a filling material 2 It relates to a heavy pipe structure.

  For example, a ductile cast iron pipe is used for fluid transportation in various fields such as water and sewage, agricultural water, industrial water, gas, electric power, and communication. The construction of a duct using this ductile cast iron pipe consists of a fume pipe or steel pipe that is propelled and buried in the soil as a sheath pipe, and a ductile cast iron pipe (new pipe) with a smaller diameter than that of the sheath pipe is inserted (laying) ) And a pipe-in-pipe method in which a ductile cast iron pipe (new pipe) having a smaller diameter than the existing pipe is inserted (laid) in the existing pipe (see Patent Document 1).

With these construction methods, there is no problem of blocking traffic as in the case of the excavation method of laying the pipe by excavating the ground, and since a new pipe will be inserted into the pipe already buried, Even if a complicated pipeline is constructed, it is possible to construct a new pipeline using a new pipeline.
JP 2002-276284 A

At this time, when the sheath tube and the new tube have a large diameter, the new tube is inserted into the sheath tube in order, and each new tube is joined through a pipe joint to form a new pipe (this figure). 1), and a filler is filled between the new pipe (new pipe) and the sheath pipe through the inlet of the new pipe (see Patent Document 2).
Japanese Patent Laid-Open No. 9-166242

In addition to the sheath tube propulsion method and the pipe-in-pipe method, pipes are also constructed by the shield method. In this method, a cavity is provided in the ground using a shield machine, a segment is installed, and a new pipe is inserted into the space to construct a pipeline (see Patent Document 3).
JP 2003-296086 A

Using these methods, after inserting a new pipe into a sheath pipe, etc., sand, cement milk, or air mortar is inserted into the gap between the start pipe or the arrival mine and the sheath pipe and the new pipe for the purpose of fixing or protecting the inserted new pipe. Etc. are used as a filler (see Patent Document 4).
JP 59-231283 A

Even in the shield method, air mortar may be filled in the gap between the segment and the new pipe in the same way, and the back-filling agent is used to suppress the fall of ground and ground subsidence in the gap between the segment and ground. (Filler) is filled (see Patent Document 5).
JP-A-9-235996

Although the pipeline is constructed by the above-described method, the existing pipeline may become unnecessary due to problems such as pipeline life and population increase, or the diameter of the pipeline may be reduced, making it unusable. If it is necessary to open the ground and remove the pipe that has become unnecessary, it is too costly, so it is necessary to leave the pipe as a waste pipe in the ground and fill the pipe with air mortar etc. Has been done.
This is because if the pipeline is left in the ground, the pipeline section is the same as a cavity in the ground, which may cause ground subsidence and the like. This is to eliminate the concern as a solid matter.

By the way, with the increase in domestic power demand, electric power manufacturers also generate the amount of fly ash generated during thermal power generation (the ash generated when coal is burned is collected with a dust collector, also called coal ash). Increasing year by year. The main components of this fly ash are silica and alumina. When mixed with cement, silica and alumina react with calcium hydroxide in the cement to cause a pozzolanic reaction and increase long-term strength. With the advantages of In addition, fly ash is spherical, and there is an advantage that if concrete is mixed with cement, the fluidity of the concrete is improved.
For this reason, fly ash is effectively used in various applications such as cement raw materials, civil engineering / building materials, fertilizers, etc., but the usage rate is still not sufficient, and in fact the new usage A method is desired.

Under the above circumstances, if the fluidity of the filler is increased, the length of one filling becomes longer, so that improvement of the fluidity is desired. By mixing a water retention agent and a fluidizing agent in the material, a filler with high fluidity could be obtained (see Patent Document 6).
JP 2006-21933 A

In general, the filler does not require high mechanical strength. In particular, the filler filled in the sheath pipe and the new pipe is filled with sand in the past. The resulting packed bed has a low mechanical strength, yet it performs well and does not require high mechanical strength. In short, it is sufficient to sufficiently fill the gap (gap). First, if the mass ratio of water to cement is increased, the fluidity will improve, but bleeding problems will occur, so mixing the water retention agent will improve the fluidity. Capture increased moisture and solve bleeding problems.
On the other hand, when a water retention agent is mixed, the fluidity is generally lowered. Therefore, mixing a fluidizing agent disperses cement, water retention agent, and the like, thereby improving the fluidity. In addition, the fluidizing agent, while entraining fine air, reduces the unit water volume by the dispersing action of cement particles, and improves workability and various characteristics.

  Furthermore, by mixing the foaming agent, it is possible to obtain a filled layer having a shape retaining property and a large number of void layers, and the shrinkage during solidification (volume shrinkage) is suppressed as much as possible, and the mechanical strength such as compression is lowered. Thereby, when a pipe joint part is an earthquake-resistant structure, expansion and contraction of the joint due to the occurrence of an earthquake is smoothly performed. If the shrinkage at the time of solidification is suppressed, the filling rate between the sheath tube and the new tube is improved.

In addition, the applicants have proposed the use of a filler obtained by adding fly ash to the filler, that is, fly ash cement, which should be used newly for fly ash (see paragraph 0014 of Patent Document 6). The fly ash cement here is defined by JIS R5213, cement: fly ash (weight ratio) = 100: 5 to 10 (class A), 100: 10 to 20 (class B), 100: 20 to 30 (class C). )
However, when fly ash cement is used and the amount of the fly ash is increased, the fluidity improving effect causes a delay in curing as described above, resulting in an increase in bleeding and a decrease in volume.

  An object of the present invention is to prevent an increase in bleeding and a decrease in volume even when the fly ash is added (when fly ash cement is used).

In order to achieve the above object, the present invention incorporates a curing accelerator in the technique of Patent Document 6 described above.
Since the curing of the filler is promoted by the mixing of the curing accelerator, even when fly ash is added, the curing delay hardly occurs, and the increase in bleeding and the volume decrease hardly occur. In the present application, the fly ash includes fly ash or a mixture of fly ash and blast furnace slag unless otherwise specified.

As a structure of this invention, it is the filler which consists of cement and water which added fly ash, Comprising: The structure which mixed the water retention agent, the fluidizing agent, and the hardening accelerator is employable.
Although various well-known things can be employ | adopted as said hardening accelerator, common sodium silicate (water glass) can be used.
At this time, it is preferable that the sodium silicate is solid (including granular and powdered), for example, sodium orthosilicate and sodium metasilicate. When sodium silicate is mixed in a mixture of cement and water, it starts to gel at the same time as the mixing, and this gelation reduces fluidity (inhibits fluidity). This is because the gelation of sodium silicate is faster in the case of liquid than in the case of solid, so the filler mixed with liquid sodium silicate cannot be filled over a long distance (sufficient filling length cannot be secured). .

The mixing amount of the curing accelerator is appropriately determined by experiment, implementation, etc. so that the delay in curing hardly occurs and the increase in bleeding and volume reduction does not occur when various amounts of fly ash are added. In the case of sodium silicate, for example, the mass of sodium silicate is 0.005 to 0.015 with respect to cement mass of 1.
If the mass of sodium silicate is less than 0.005, bleeding due to curing delay occurs, and if it exceeds 0.015, fluidity deteriorates due to acceleration of curing.

  As the cement, various components can be employed. For example, ordinary portland cement, blast furnace cement, fly ash cement, and the like are employed because they are inexpensive and easily available. The fly ash cement is a mixture of fly ash or a mixture of fly ash and blast furnace slag that is desired to be treated (utilized) as described above. However, the amount of the fly ash or the mixture may be 1 to 8 with respect to the cement mass of 1, for example. . If the mass is less than 1, a decrease in the amount of fly ash used becomes a problem. If the mass exceeds 8, the deterioration of fluidity and the increase in bleeding are problematic. When the mass ratio is 1 to 8, no bleeding occurs despite the addition of fly ash.

  As the water retention agent, montmorillonite or bentonite containing it as a main component is desirable because it has a large water retention effect and is excellent in reducing bleeding.

  As a fluidizing agent, lignin sulfonate, oxycarboxylate, polyol derivative, polyoxyethylene alkyl allyl ether derivative, alkyl allyl sulfonate formalin condensate, melamine sulfonate formalin condensate, polycarboxylic acid type Examples of the polymer compound include alkylallyl sulfonates, formalin condensates of melamine sulfonates, and lignin sulfonates in view of the great effect of reducing the thickening effect due to the addition of a water retention agent.

  There are two types of foaming agents: organic surfactants such as synthetic surfactants and hydrolyzed proteins, and metallic ones. Since organic ones are liquid, they can be used as powdery materials such as water retention agents and fluidizing agents. Since it is difficult to premix, a metal powder is desirable. Specifically, metal powders such as aluminum, barium, magnesium, and zinc can be used, but they are inexpensive and easily available, and the nature of the gas (does not adversely affect the filler itself or the pipe, such as corrosion). For example, aluminum powder is preferable.

  Here, as a combination of a fluidizing agent and a foaming agent, a combination of lignin sulfonate and aluminum powder is most desirable in consideration of a balance between fluidity, curability and bleeding.

As the mixing ratio thereof, for example, with respect to cement mass: 1, bentonite mass containing montmorillonite as a main component: 0.096 to 0.24, metal powder mass: 0.00025 to 0.001, and lignin Sulfonate mass: 0.002-0.01, sodium silicate mass: 0.005-0.015, preferably 0.01-0.015 can be employed.
When the bentonite is less than the specified value: 0.096, problems such as poor swelling, bleeding, and volume shrinkage occur, and when it exceeds the specified value: 0.24, problems such as thickening and poor flow occur. . When the amount of lignin sulfonate is less than the specified value: 0.002, a problem of poor flow occurs. When the amount of lignin sulfonate is more than the specified value: 0.01, problems of bleeding and curing delay occur. When the amount of the metal powder is less than the specified value: 0.00025, there is a problem similar to that of the bentonite. When the amount is more than the specified value: 0.001, problems of overexpansion and poor flow occur. If the amount of sodium silicate is less than the specified value: 0.005, there is a problem that bleeding due to curing delay occurs. If the amount is more than the specified value: 0.015, there is a problem that fluidity is deteriorated due to acceleration of curing.
Sodium silicate gels at the same time as kneading with cement slurry, so if it is not a plant with sufficient kneading performance, it may become a non-uniform filler, and because of the strong alkalinity of sodium silicate, There are dangers when working in For this reason, it is preferable that the amount of sodium silicate mixed is as small as possible.

  The mass ratio of the cement and water may be appropriately set according to the purpose of use based on the strength of the filler, the mixing amount of the fluidizing material, and the like. Can do.

Further, although the foaming time of the metal powder continues for a considerably long time, if the filler flows after the expansion due to foaming ends, bubbles generated from the metal powder may disappear and volume shrinkage may occur. On the other hand, if the hardening of the filler starts before the expansion due to foaming ends, the distribution of bubbles becomes uneven or the expansion becomes insufficient, which may cause volume shrinkage. As described above, the control of the foaming speed is very important in the blending of the filler.
Here, in general, when the particle size of the metal powder is small (the specific surface area is large), the foaming rate is increased, and when the particle size is large (the specific surface area is small), the foaming rate is decreased. For this reason, by setting the range of the particle size of the metal powder to 1 to 500 μm, preferably 80 to 200 μm, in the normal filling operation, the foaming occurs between the end of the flow of the filler and the start of curing. As is done, the foaming rate can be controlled.

These fillers can be used as fillers between the pipes and the sheath pipes by inserting the pipes one after another into a sheath pipe laid in the ground and joining the pipes together to form a pipe. Can be used as the above-mentioned various fillers such as fillers in the pipe, and in the case of the former filler, a double pipe piping structure in which the filler is filled between the new pipe and the sheath pipe; Become.
In this filling method, the water retention agent, fluidizing agent and curing accelerator, or water retention agent, fluidizing agent, curing accelerator and foaming agent are each in powder form, and they are premixed to flow. Make a chemical, mix and stir the mixture of the fluidizing material and water with the cement added with fly ash (mixed with 1.5 liquid) to make the filler,
The mixture of the fluidizing material and water and the mixture of fly ash-added cement and water can be mixed and stirred (mixed with two liquids) to form a filler.
The fluidizing material may be made on site or made in a factory and brought to the site.

By the way, when making a slurry in a system in which bentonite is mixed with cement-derived alkali, if the kneading is a one-liquid mixture (see Patent Document 7), bentonite is affected by the alkali of the cement and takes in water. It may disappear and cause poor swelling. Even if the swelling failure can be avoided in the first kneading, there is usually only one plant. Therefore, if the plant is not washed for each kneading, bentonite newly added by the remaining cement will be High risk of being affected by alkali. For this reason, when the filler is continuously kneaded without washing the plant, there is a risk of causing poor swelling.
On the other hand, in the above 1.5 liquid mixing and 2 liquid mixing, a water retention agent (bentonite), a fluidizing agent, a foaming agent, and sodium silicate are kneaded (mixed) in a plant (for example, a container) separate from cement. Therefore, the water retaining agent takes in water without being affected by the alkali content of the cement, and is then kneaded with the cement. For this reason, there is no problem even if the filler is continuously kneaded without washing the plant.
JP 2006-213589 A

  Of course, the above filler can be used not only for filling pipes of various pipe structures of water and sewage systems but also for gaps such as pipes by shield method, waste pipes, and other crust gaps. is there.

As described above, according to the present invention, a filler having high fluidity can be obtained by mixing a water retention agent and a fluidizing agent. For this reason, long-distance filling is possible and workability can be improved.
If a foaming agent is mixed, the mechanical strength can be lowered while maintaining the function of the filler.
Further, since the curing of the filler is promoted by mixing the curing accelerator, curing delay hardly occurs even when fly ash is added, and no increase in bleeding and volume reduction occur.

  This embodiment is an example of renewal of the agricultural water tunnel A, as shown in FIG. 1, and is in an existing pipe (sheath pipe) A buried between the start pit S and the arrival pit R. A new pipe P having a smaller diameter is inserted and laid, and a filler a is filled between the new pipe P and the sheath pipe A. As in the conventional case, a hydraulic jack J is installed in the start pit S. The rear portion of the hydraulic jack J abuts against the reaction force receiver H, and the front portion presses the new pipe P via the push angle B. The new pipe P is sequentially joined by inserting the insertion port 1 at the tip thereof into the receiving port 2 at the rear end of the preceding new pipe P, and is pushed into the existing pipe A to form the new pipe P ′. Form.

At this time, the pipe joint portion is a PII type, S type, NS type, SII type or the like earthquake resistant pipe joint. For example, as shown in FIG. 2, a protrusion 3 is provided at the tip of the insertion slot 1, a lock ring 5 is provided on the inner surface of the receiving opening 2 via a centering rubber 4, and a sealing rubber ring 6 is interposed in the receiving opening 2. NS type in which the insertion port 1 is inserted and the projection 3 (the tip of the insertion port 1) is movable between the lock ring 5 and the inner end 2a of the inner surface of the receiving port so that the expansion allowance L of the insertion port 1 is secured. Use a joint. In this NS type joint, the insertion port 1 is retracted until the projection 3 abuts against the lock ring 5 (distance L ₁ ) with respect to the pulling force, and the tip of the insertion port 1 is against the insertion force. It is inserted until it comes into contact with the back end 2a (distance L ₂ ) to prevent the joint from being damaged (see Patent Document 1).

  If the transfer and connection of the new pipe P into the sheath pipe A is completed over the entire construction zone (the entire length of the tunnel), the filler (grouting material) a between the sheath pipe A and the new pipe P is the same as before. (See Patent Documents 2 and 7, etc.).

Filling means of the filling material a, as shown in FIG. 3, water retention agents, flow agents, curing accelerator and a blowing agent respectively and form of powder, they are premixed to make a fluidizing material a ₁ Then, the fluidizing material a ₁ and water w are kneaded, and then the mixture (fluidizing material slurry) a ₂ and the cement s to which fly ash is added (mixed) are mixed and stirred (kneaded). a is prepared (1.5 liquid mixture), and the filler a is fed between the sheath tube A and the new tube P through the injection tube 10. In the figure, 11 is a pressure gauge.

In addition, as shown in FIG. 4, the other filling material a is filled with a water retention agent, a fluidizing agent, a curing accelerator, and a foaming agent in powder form, and premixed so that the fluidizing material a ₁ and a mixture (fluidizing material slurry) a _{2 of} the fluidizing material a ₁ and water w, and a mixture (cement slurry) a ₃ of cement s and water w added (mixed) with fly ash. Then, the mixture is fed into the static mixer 12 and mixed and stirred to form a filler a (two-liquid mixing), and the filler a is fed between the sheath pipe A and the new pipe P through the injection pipe 10.

At this time, as the composition of the filler a, the mass of bentonite whose main component is the montmorillonite: 0.096 to 0.24, the mass of the metal powder: 0 with respect to the cement mass: 1 with the fly ash added. 0.025 to 0.001, the lignin sulfonate mass: 0.002 to 0.01, and the sodium silicate mass: 0.005 to 0.015.
According to each blending ratio within this range, each of “Consistency (fluidity)”, “Bleeding”, and “Volume change” when the filler a is fed between the sheath tube A and the new tube P of this example. The test results are shown in Table 1 below, and the evaluation criteria are shown in Table 2 below. In Table 1, “Δ” means that it can be used or cannot be used in some cases, and can be used if it is appropriately selected depending on the use conditions and the like. In particular, the consistency (fluidity) can be used as long as the fluidity immediately after kneading is good (if it is o). During the test, it was at room temperature (25 ° C.).

From this test result, it can be confirmed that the filler a according to the present invention is sufficiently satisfactory in terms of fluidity (consistency), presence / absence of bleeding, volume shrinkage (volume change rate), and the like.
Moreover, in each Example 1-4, since sodium silicate (water glass) is also small with 0.005-0.015 mass with respect to cement mass: 1, there is also little danger based on the strong alkalinity of water glass, There was no non-uniform component of filler a due to rapid gelation of water glass.

The above embodiment was a case of renewal of the agricultural water tunnel A, but the present invention is not limited to renewing the agricultural water tunnel A, but to renew existing pipes such as water and sewage pipes. Not only the existing pipe renewal method and pipe-in-pipe method such as forming a new pipe by sequentially inserting new pipes into the tube as a sheath pipe, but also the pipe-in water channel method for installing pipes in the existing water channel, Furthermore, when pipes such as gas pipes are installed in the ground, it goes without saying that they can also be used in construction methods in which a sheath pipe is provided outside the pipe to prevent damage to the anticorrosion coating of the pipe and to protect the pipe after installation. Yes.
At that time, for example, in a pipe without an opening such as a water pipe instead of a pipe with an opening at both ends of a tunnel or the like, for example, a shaft is formed and the new pipe P and various equipment are carried into the shaft Then, the new tube P is inserted and the filling material a is filled.

  Moreover, the filling according to the present invention is not limited to the use in the double pipe structure in the sheath tube propulsion method and the pipe-in-pipe method, but is used to fill the gaps of pipes, waste pipes and other crustal voids by the shield method. It goes without saying that the material can be used.

Illustration of pipe-in-pipe method NS type joint cross section Operational explanatory diagram of the embodiment Other operation explanatory view of the same embodiment

Explanation of symbols

A Sheath pipe P 'New pipe P New pipe a Filling material (grouting material)
a ₁ Fluidizing material premixed with water retention agent a ₂ Fluidizing material a ₁ and water mixture (fluidizing material slurry)
a ₃ Cement and water mixture (cement slurry)
s Cement w Water 10 Injection pipe (hose)
12 Static mixer

Claims (12)

  A filler (a) to which fly ash composed of cement and water is added, wherein a water retention agent, a fluidizing agent, and a curing accelerator are mixed.   The filler according to claim 1, wherein solid sodium silicate is used as the curing accelerator.   The filler according to claim 2, wherein the mass of the sodium silicate is 0.005 to 0.015 with respect to the cement mass is 1.   The filler according to any one of claims 1 to 3, wherein the mass of the fly ash or a mixture of fly ash and blast furnace slag is 1 to 8 with respect to the cement mass of 1.   The filler according to any one of claims 1 to 4, wherein the water retention agent is montmorillonite and the fluidizing agent is lignin sulfonate.   The filler according to any one of claims 1 to 5, wherein a foaming agent is further mixed.   The filler according to claim 6, wherein the foaming agent is a metal powder.   Mass of bentonite with montmorillonite as a main component as the water retention agent: 0.096 to 0.24, mass of the metal powder: 0.00025 to 0.001, and the fluidizing agent with respect to the cement mass of 1. The lignin sulfonate salt mass: 0.002 to 0.01, and the sodium silicate mass serving as the curing accelerator: 0.005 to 0.015, The filler according to claim 7.   Pipes (P) are sequentially inserted into the sheath pipe (A) laid in the ground, and the pipes (P) are joined together with pipe joints to form pipes (P '). Filling with filling material (a) according to any one of claims 1 to 8 as filling material (a) between P ') and said sheath tube (A) via injection tube (10) Material filling method. The above water retention agent, fluidizing agent and curing accelerator, or water retention agent, fluidizing agent, curing accelerator and foaming agent are each in powder form, premixed to make a fluidizing material (a ₁ ), The mixture (a ₂ ) of the fluidizing material (a ₁ ) and water (w) is mixed and stirred with cement (s) to which fly ash is added to form the filler (a). Item 10. A filling method according to Item 9. The above water retention agent, fluidizing agent and curing accelerator, or water retention agent, fluidizing agent, curing accelerator and foaming agent are each in powder form, premixed to make a fluidizing material (a ₁ ), as fluidization medium and (a ₁₎ a mixture of water (w) and (a _2), a mixture of cement with the addition of fly ash (s) and water (w) and (a _3), mixed and stirred to It is said filler (a), The filling method of the filler of Claim 9 characterized by the above-mentioned.   Pipes (P) are sequentially inserted into the sheath pipe (A) laid in the ground, and the pipes (P) are joined together with pipe joints to form pipes (P '). A double-pipe piping structure in which the filler (a) according to any one of claims 1 to 8 is filled as a filler (a) between P ') and the sheath pipe (A).

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