JP5025584B2 - Filler - Google Patents

Description

  This invention is filled with void filling material used for filling voids such as water and sewage pipes, piping by shield method, waste pipes and other crust voids, a filling method of the filling material, and the 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 is carried out by embedding a fume pipe or steel pipe in the soil as a sheath pipe, and inserting a ductile cast iron pipe (new pipe) having a smaller diameter than the sheath pipe into the sheath pipe (laying out) ) 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 FIG. 1 and 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.

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 at the time of 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 a joint by the occurrence of an earthquake is made smoothly. If shrinkage during solidification is suppressed, the filling rate between the sheath tube and the new tube is improved.

  This filler has become effective due to the above-described effects. However, when the temperature is low, for example, 10 ° C. or lower, there is a problem that bleeding increases and volume decreases due to delay in curing.

  An object of the present invention is to prevent an increase in bleeding and a decrease in volume even at low temperatures.

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, the curing delay hardly occurs even at a low temperature, and the increase in bleeding and the volume decrease hardly occur.

As a structure of this invention, it is a filler which consists of cement and water, 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 may be appropriately determined by experiments, working, etc., so that curing delay is unlikely to occur at various low temperatures and no increase in bleeding and volume reduction occurs. In this case, for example, the mass of the sodium silicate: 0.005 to 0.02 with respect to the cement mass: 1.
When the mass of sodium silicate is less than 0.005, bleeding due to curing delay occurs, and when it exceeds 0.02, 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 defined by JIS R5213. Cement: fly ash (weight ratio) = 100: 5 to 10 (A type), 100: 10 to 20 (B type), 100: 20 to 30 (C type) To tell.

  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 in liquid form, 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: 0.005-0.02, 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 occurs due to curing delay. If the amount is more than the specified value: 0.02, 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 agent, and the like, for example, 1: 1.0 to 10.0. Can do.
Here, the compression strength after solidification of the filler can be 0.1 to 2.0 N / mm ^2, and at that time, the compression strength after solidification is 0.1 to 1.N as a low-strength filler. In the case of 0 N / mm ² , the mass ratio of cement to water is preferably in the range of 1: 2.5 to 10.0. On the other hand, when the compressive strength after solidification is 1.0 to 2.0 N / mm ² as a high-strength filler, the same mass ratio is desirably in the range of 1: 1.0 to less than 2.5.

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 non-uniform 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.

As described above, the compressive strength after solidification of the filler can be 0.1 to 2.0 N / mm ² , but the components of the filler are blended at a predetermined ratio for the purpose of low strength. If the compressive strength after solidification is 0.1 to 1.0 N / mm ² , the expansion and contraction of the joint portion can be reliably ensured when used as a filler for a double pipe structure of a seismic pipe joint. It can be. In addition, if the components of the filler are blended at a predetermined ratio for the purpose of high strength and the compression strength after solidification is 1.0 to 2.0 N / mm ² , the same as conventional materials such as air mortar Can be used.

  These fillers can be used as fillers between the pipe and the sheath pipe by inserting the pipes one after another into a sheath pipe laid in the ground and joining the pipes together. It can be used as a filler in the pipe and the above-mentioned various fillers. In the case of the former filler, a double pipe piping structure in which the filler is filled between a new pipe and a 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 the fluidized material and water (slurry) with cement and stir (mixed with 1.5 liquid) to make the filler,
A mixture (slurry) of the fluidizing material and water and a mixture (slurry) of cement and water can be mixed and stirred (mixed with two liquids) to obtain a filler.
The fluidizing material may be made on site or made in a factory and brought to the site. In addition, when filling the double pipe structure in which the pipes are joined together, when the joining of the pipes is based on an earthquake-resistant pipe joint, the fluidizing material includes a water retention agent, a fluidizing agent, a hardening accelerator, and A foaming agent is premixed. A fluidized material filler premixed with this foaming agent becomes a packed layer with many shape-retaining void layers, and the mechanical strength such as compression is reduced. This is because it can be secured.

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, the above 1.5 liquid mixing and 2 liquid mixing is carried out by kneading (stirring mixing) water retention agent (bentonite), fluidizing agent, foaming agent, sodium silicate in a plant (for example, container) different from cement. Therefore, since the water retention agent takes in water without being affected by the alkali content of the cement and is then kneaded with the cement, there is no inconvenience in the case of the one-liquid mixing. 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.
In addition, if a foaming agent is mixed, the mechanical strength can be lowered while maintaining the function of the filler, and therefore, in the earthquake-resistant pipe joint structure, expansion and contraction of the joint portion can be ensured reliably.
Furthermore, since the curing of the filler is promoted by mixing the curing accelerator, the curing delay hardly occurs even at a low temperature, and the increase in bleeding and the decrease in volume do not occur.

  This embodiment is an example of renewal of the agricultural water tunnel A, as shown in FIG. 1, and is installed in an existing pipe (sheath pipe) A buried between the start pit S and the arrival mine 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. This NS type joint is retracted until the projection 3 comes into contact with the lock ring 5 (distance L ₁ ) with respect to the pulling force, and the tip of the insertion port 1 with respect to 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 The fluidizing material a ₁ and water w are kneaded, and then the mixture (fluidizing material slurry) a ₂ and cement s are mixed and stirred (kneaded) to form a filler a (1.5 liquid mixing) ), 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 , a fluidized material a ₁ and a mixture of water w (fluidized material slurry) a ₂ and a mixture of cement s and water w (cement slurry) a ₃ are mixed into a mixer such as a static mixer 12. The mixture is 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 powdered sodium silicate: 0.005 to 0.02, the mass of powdered bentonite mainly composed of montmorillonite: 0.096 to the mass of cement: 1 The mixing ratio is 0.24, metal powder mass: 0.00025 to 0.001, and powdered lignin sulfonate mass: 0.002 to 0.01.
“Consistency (fluidity)”, “bleeding”, and “volume change” test when the filler a is fed between the sheath tube A and the new tube P of this example according to each blending ratio within this range. The 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). The temperature during the test was 3 ° 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.
Further, in Examples 1 to 4, there was no swelling failure of the slurry filler a, and there was no need to clean this plant. Furthermore, since sodium silicate (water glass) is also less than 0.005 to 0.02 mass relative to cement mass: 1, there is little risk based on the strong alkalinity of water glass, and due to rapid gelation of water glass There was no component non-uniformity of the filler a.

In the above-mentioned embodiment, the case was an update of the agricultural water tunnel A. However, the present invention is not limited to the update of the agricultural water tunnel A. 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, not only the use in the earthquake-resistant double pipe piping structure in the sheath pipe propulsion method and the pipe-in-pipe method, but also the double pipe piping structure other than the earthquake resistance, the gap by the shield method, the waste pipe, etc. Needless to say, the filler a of this embodiment can be used to fill the crust voids.

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 (3)

Ri Do cement and water, water retention agents, fluidizing agents, were mixed hardening accelerator and a blowing agent, the gap between the sleeve pipe and the new pipe in the sheath pipe jacking method, existing pipe and the new pipe in the pipe-in-pipe method Oite gap, the gap between the segments and the new tube shield method, the gap between the segments and the natural ground shield method, or the filler to the waste tube between,
The blowing agent is Ri metal powder der, granular or powdered sodium silicate as above Symbol curing accelerator, the montmorillonite as the water retention agent, and using a lignin sulfonate as the fluidizing agent, the cement mass: for one, the water mass: 1.0-10.0, bentonite mass mainly containing montmorillonite: 0.096 to 0.24, the metal powder mass: 0.00025 to 0.001, the lignin Sulfate mass: 0.002-0.01, the said sodium silicate mass: 0.005-0.02, The filler characterized by the above-mentioned . A gap between the sheath pipe and the new pipe of the sheath pipe propulsion method, which is made of cement and water and mixed with a water retention agent, a fluidizing agent, a hardening accelerator, and a foaming agent. The water retention agent, fluidized, used in the production of the gap between the gap, the gap between the shield method segment and the new pipe, the gap between the shield method segment and the ground, or the filler in the waste pipe Fluidizing material (a ₁ ) in which an agent, a curing accelerator and a foaming agent are mixed,
The foaming agent is metal powder, the curing accelerator is granular or powdered sodium silicate, the water retention agent is powdered montmorillonite, and the fluidizing agent is powdered lignin sulfonate, and the mass ratio is Bentonite mainly composed of montmorillonite: metal powder: lignin sulfonate: sodium silicate = 96 to 240: 0.25 to 1: 2 to 10: 5 to 20, a fluidizing material. Sheath pipe laid in the ground in the sheath pipe jacking method or pipe-in-pipe construction method of (A) or an existing pipe that each new tube by inserting new tubes (P) in sequence in (A) (P) The pipe (P ') is formed by joining together with a pipe joint, and the filler (a) is provided between the pipe (P') and the sheath pipe (A) or the existing pipe (A ) as claimed in claim 1 . A filling material filling method for filling a filling material (a) through an injection tube (10).

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