JP2006021933A - Filler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a filler capable of filling to a distant place due to high fluidity and thus, improving workability. <P>SOLUTION: This filler is obtained by blending, by weight based on 1 of cement, 0.05-0.45 bentonite, 0.00005-0.001 metal powder, 0.0015-0.05 lignin sulfonate and 1.0-10.0 water. By blending bentonite to catch the increasing amount of water, a bleeding problem is solved. The blend of lignin sulfonate improves fluidity by dispersing cement, a water retaining agent or the like. Further, a filling layer many in void layer having shape retainability is obtained by the foaming of metal powders. The increase of voids in the filling layer brings about the improvement of fluidity and the lowering of mechanical strength such as compression. In the case of a pipe joint having quakeproof structure, expansion or retraction caused by occurrence of earthquake is smoothly performed by adjusting the blending ratio of bentonite or the like so as to regulate compression strength to 0.1-1.0 N/mm<SP>2</SP>, and if regulated to 1.0-2.0 N/mm<SP>2</SP>, the filler similar to a conventional one is obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a void filler used to fill voids such as water and sewage pipes, piping by shield construction, waste pipes, and other crust voids.

  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

  For example, in the pipe-in-pipe method, as shown in FIG. 1, a new pipe P having a smaller diameter than that in the existing pipe (sheath pipe) A embedded between the start pit S and the arrival pit R is provided. The hydraulic jack J is installed in the start pit S, the rear part of the hydraulic jack J abuts against the reaction force receiving H, and the front part presses the new pipe P through the pushing angle P. It has become. 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. A leading sled K for reducing insertion resistance is attached to the tip of the leading new pipe P.

  In these sheath tube propulsion methods, etc., today, the pipe joint part is constructed by inserting the insertion port of one pipe into the receiving port of another tube via a rubber ring, and the insertion port is connected to the receiving port. Is generally an earthquake-resistant structure that can be expanded and contracted (removable), and there are PII type, S type, NS type, SII type, etc. as its joints.

The seismic tube joint is usually one in which the protrusion on the outer peripheral surface of the insertion port can be moved between the protrusion on the inner surface of the receiving port and the rear end portion. 2, a protrusion 3 is provided at the tip of the insertion slot 1, and a lock ring 5 is provided on the inner surface of the reception opening 2 via a centering rubber 4, and the insertion opening 2 is inserted through a rubber ring 6 for sealing. 1 is inserted, the projection 3 (the tip of the insertion port 1) can be moved between the lock ring 5 and the inner end 2a of the inner surface of the receiving port, and the expansion / contraction allowance L of the opening 1 is secured. For the force, the insertion slot 1 is retracted until the projection 3 abuts against the lock ring 5 (distance L ₁ ), and for the insertion force, the tip of the insertion slot 1 abuts the back end 2a. (Distance L ₂ ) to prevent the joint from being damaged (see Patent Document 1).

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 2).
JP 2003-296086 A

After inserting the new pipe P into the sheath pipe A or the like by these methods, for the purpose of fixing and protecting the inserted new pipe P, the gap between the sheath pipe A and the new pipe P from the start pit S or the arrival pit R Filling with sand, cement milk, air mortar or the like as a filler is performed (see Patent Document 3). At this time, if the filling distance becomes long, it is difficult to fill the entire pipe line with a single filling.Therefore, vertical pores reaching the ground surface are provided at appropriate positions in the longitudinal direction of the sheath pipe, etc. The section divided by the holes is filled with the vertical pores.
JP 59-231283 A

Further, when the sheath tube A and the new tube P are of a large diameter, as shown in FIGS. 3 and 4, the new tube P is inserted into the sheath tube A in order, and each new tube P is connected to the tube. A new pipe P is formed by joining through the joint C (FIG. 3), and the grout material a is filled between the new pipe P (new pipe P) and the sheath pipe A through the inlet of the new pipe P. There is a thing (refer patent document 4).
Japanese Patent Laid-Open No. 9-166242

  In this construction method, the grout material a is filled with about 15 to 20 new pipes P in a single grout material a filling range, and an intermediate partition is formed between the new pipe P and the sheath pipe A at both ends of the range. A wall D is formed, and the grout material a is injected between the new pipe P and the sheath pipe A from the inlet formed in the new pipe P. In addition, the partition wall D is also formed in the end opened to the start pit S and the arrival mine R.

  In addition, a plurality of hoses are inserted between one end (for example, start shaft S) between the new pipe P and the sheath pipe A, and the insertion length of each hose is set in the length direction, for example, every 50 m ( There is also a construction method in which the grout material a is fed from each hose at different intervals: 50 m). Incidentally, if the insertion length of each hose is different every 50 m, the filling length of the grout material a by one hose is 50 m.

Even in the shield method, air mortar may be filled in the gap between the segment and the new pipe P in the same way, and the gap between the segment and the ground is backed up to suppress ground fall and ground subsidence. An agent (filler a) is filled (see Patent Document 5).
JP-A-9-235996

Furthermore, although the pipe line is constructed by the above-described method or the like, the existing pipe line may become unnecessary due to problems such as the pipe life and population increase, or the diameter of the pipe line may be reduced and may not be used. 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 portion is the same as the ground has a cavity, so there is a risk of causing ground subsidence, etc. In order to increase the ground strength by eliminating the hollow part as a solid.

  As described above, fillers such as air mortar have a wide variety of uses. However, the filling method of the filler provided with longitudinal pores forms a plurality of longitudinal pores when the filling distance is long. Therefore, the cost is increased, and a space for forming vertical pores is necessary, and the space may not be ensured due to road conditions or the like. In that case, the filler must be filled over a long distance, and the filler is required to have good flowability (fluidity).

Even when the vertical pores are not provided, the fluidity of the filler a may be reduced due to the state of the gap between the sheath tube A and the new tube P, and improvement in fluidity may be required.
In any case, if the distance between the laying pipe line and the waste pipe becomes long, the entire pipe line may not be filled, and it is desirable that the fluidity of the filler is high.

  Furthermore, in order to ensure the maximum fluid flow rate in the new pipe P, if a new pipe P having a large nominal diameter, for example, a new pipe P having a small diameter is inserted into the sheath pipe A, the gap between them becomes minimal. In the case of the filler a having low fluidity, the possibility that the filler a does not rotate over the entire area of the pipe P increases. Nowadays, since it is usually required to secure the maximum fluid flow rate in the new pipe P, a filler with good fluidity is desired.

  Moreover, since a person cannot enter the pipe P having a nominal diameter of 700 or less by law, in order to check the filling of the filler a, an intermediate vertical hole is provided at an appropriate position in the length direction of the pipe. Although confirmation is done, it causes traffic congestion, so it is impossible to form the intermediate standing hole at any position, and such confirmation method can only be done in a limited place . In this case, it is desired that the filler a be highly fluid and the confirmation thereof be omitted.

  Furthermore, in the method of filling the filler (grouting material) a from the inlet of each new pipe P or by a plurality of hoses, if the fluidity of the filler a is improved and the filling distance is increased, it is only that. In addition, the workability is improved such that the injection position becomes an injection port for several new pipes P, the interval between the insertion lengths of the respective hoses can be increased, and the number of hoses can be reduced.

  In general, as a method for improving fluidity, it is sufficient to increase the amount of water mixed in the cement. However, when the amount of water increases, aggregate (sand, etc.) settles and uniform filler a Cannot be obtained and the problem of breathing comes out.

Further, in the pipe of the above earthquake-resistant joint, the filler a such as air mortar filled after inserting the new pipe P into the sheath pipe A has a compressive strength after solidification of 1.0 N / mm ² or more. Since it is high, there is a possibility that the expansion and contraction of the joint due to the occurrence of an earthquake may not be smoothly performed.

  This invention makes it a subject to obtain a filler with high fluidity | liquidity.

  In order to achieve the above object, the present invention mixes a water retention agent and a fluidizing agent in a conventionally known filler made of cement and water.

  In general, the filler does not require high mechanical strength. In particular, in the case where the sheath tube and the new tube are filled, the past is filled with sand, and the packed layer made of the sand is The mechanical strength is low, yet it performs well and high mechanical strength is not required. In short, it is sufficient to sufficiently fill the gap (gap).

For this reason, if the weight ratio of water to cement is first increased, the fluidity is improved, but the problem of breathing occurs. For this reason, by mixing a water retention agent, the water | moisture content increased in order to improve the fluidity | liquidity is trapped, and the problem of breathing is solved.
On the other hand, when a water retention agent is mixed, generally fluidity | liquidity falls. For this reason, by mixing a fluidizing agent, cement, a water retention agent, etc. are disperse | distributed and fluidity | liquidity is improved. 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 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.

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.

As an embodiment of the present invention, it is possible to adopt a configuration in which cement and water are used as a basic composition of a filler, and a water retention agent and a fluidizing agent are mixed therein. Moreover, when mixing a foaming agent, the foaming agent can be made into a metal powder.
Here, although all kinds of cement can be used as the cement, ordinary portland cement, blast furnace cement, fly ash cement and the like are desirable because they are inexpensive and easily available.

  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 breathing.

  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 breathing.

  As the mixing ratio thereof, for example, for cement weight: 1, bentonite weight: 0.05 to 0.45, preferably 0.10 to 0.25, metal powder weight: 0.00005 to 0.001, Preferably, 0.00015 to 0.0003, lignin sulfonate weight: 0.0015 to 0.05, preferably 0.005 to 0.015 can be employed.

  If the bentonite is less than the specified value (0.05), problems such as poor swelling, occurrence of breathing and volume shrinkage occur, and if it exceeds the specified value (0.45), problems such as thickening and poor flow. Occurs. If the amount of lignin sulfonate is less than the specified value (0.0015), a problem of poor flow occurs. If the amount of lignin sulfonate exceeds the specified value (0.05), problems such as occurrence of breathing and delay in curing occur. When the amount of the metal powder is less than the specified value (0.00005), there are the same problems as the bentonite. When the amount is more than the specified value (0.001), problems such as overexpansion and poor flow occur.

The weight 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. At} that time, as the low-strength filler, the compression strength after solidification is 0.1 to 1.N. In the case of 0 N / mm ² , the weight 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 weight 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 filler starts to be cured 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), 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 ensured reliably in the case of using a grout material for a double-pipe structure of an earthquake resistant 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 a grout material 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. In the case of the former grout material, a double pipe piping structure in which the grout material is filled between the new pipe and the sheath tube A can be used. .

  Moreover, this filler can be used not only for filling pipes of various double-pipe piping structures for water and sewage systems but also for filling voids such as piping by a shield method, waste pipes, and other crust voids.

  Table 1 shows the composition of the filler consisting of cement, bentonite, metal powder, fluidizing agent, and water, and various test results. In the composition table, “◎” indicates that the material itself was used.

  As an evaluation item of the fluidity of the filler, a flow property test and a consistency test were performed. In addition, as a basic test for the filler, a breathing test, a volume change test, and a uniaxial compressive strength test were performed.

(Flow value test) JHS: Japan Highway Public Corporation standard
Measured by the cylinder method of JHS A 313-1992 “Testing methods for air mortar and air milk”. Specifically, the filler is placed in a cylinder with a diameter of φ80 mm x height of 80 mm that is placed on a smooth plate surface, and this is quickly pulled up vertically to measure the maximum and minimum dimensions of the filler spread on the plate surface. To do.

(Consistency test) JSCE: Japan Society of Civil Engineers
In accordance with JSCE F 531-1999 “PC grout fluidity test method”, measure the flow time of the filler through the J14 funnel.

(Breathing test)
Inject 400 ml of filler into a 500 ml graduated cylinder, seal the top opening with a wrap film, measure the amount of breathing water (A ml) after standing for 24 hours, and convert it to the breathing rate using the following formula. evaluate.
Breathing rate = {100 x Breathing water volume (A)} ÷ 400

(Volume change test)
Fill the 500 ml graduated cylinder with 400 ml of filler, seal the top opening with a wrap film, measure the volume change (B ml) after standing for 24 hours, and convert it to the volume change rate using the following formula. And evaluate.
Volume change rate = {100 × volume change (B)} ÷ 400

(Uniaxial compressive strength test) JSCE: Japan Society of Civil Engineers Standard Uniaxial compressive strength at the age of 28 days was measured by JSCE G 505-1999 “Compression test method of mortar or cement paste using cylindrical specimen”.

  According to this test result, each example obtained a satisfactory result “◯” in each test, whereas in each comparative example, a result “Δ” that could not be satisfied in any of the tests. Or it becomes "x". From this, it can confirm that an Example can achieve required objectives, such as being able to obtain a filler with high fluidity.

(Construction Example 1: Filler setting strength: 0.5 N / mm ² )
When used as a filler for the double-pipe piping structure shown in FIG. 3 and FIG. 4, the interval between the inlets 7 can be 50 m or more. Sufficient expansion and contraction could be obtained. At this time, the existing pipe nominal diameter: 27 inches, the new pipe nominal diameter: 500 mm, the pipeline extension was 100 m, and the gap volume was 20 m ³ . A commercially available grout pump (filling speed: about 40 L / min) was used for filling. The filling time was about 9 hours.

(Construction Example 2: Filler setting strength: 2.0 N / mm ² )
When used as a filler for the double pipe piping structure shown in FIGS. 3 and 4, the interval between the inlets 7 could be 50 m or more. At this time, the nominal diameter of the sheath pipe: 900 mm, the nominal diameter of the new pipe: 500 mm, the pipeline extension was 200 m, and the gap volume was 80 m ³ . A commercially available grout pump (filling speed: about 200 L / min) was used for filling. The filling time was about 7 hours.

  The embodiment was used in the double pipe construction in the sheath pipe propulsion method and the pipe-in-pipe construction method, but not limited to this construction method, various water and sewage pipes, piping by the shield construction method, waste pipes, etc. It goes without saying that the filler of this embodiment can be used to fill voids and other crust voids.

Illustration of pipe-in-pipe method NS type joint cross section Illustration of construction of double pipe piping structure Diagram of construction Diagram of construction

Explanation of symbols

A Sheath pipe P 'New pipe P New pipe a Filling material (grouting material)

Claims (9)

  A filler comprising cement and water, wherein a water retention agent and a fluidizing agent are mixed.   The filler according to claim 1, further comprising a foaming agent.   The water retention agent is montmorillonite and the fluidizing agent is lignin sulfonate, or the water retention agent is montmorillonite, the fluidizing agent is lignin sulfonate and the foaming agent is a metal powder. Or the filler of 2.   Bentonite weight: 0.05 to 0.45 based on the montmorillonite, metal powder weight: 0.00005 to 0.001, weight of the lignin sulfonate: 0.0015 It is -0.05, The filler of Claim 3 characterized by the above-mentioned.   The filler according to claim 3 or 4, wherein the metal powder has a particle size of 1 to 500 µm.   The filler according to any one of claims 1 to 5, wherein a weight ratio of the cement to water is 1: 1.0 to 10.0. Filling material according to any one of claims 1 to 6 compressive strength after solidification, characterized in that a 0.1~2.0 N / mm ^2.   Pipes P are sequentially inserted into the sheath pipe A laid in the ground, and the pipes P are joined together to form a pipe P ′, and a grout material a between the pipe P ′ and the sheath pipe A is formed. A method for filling a grout material, which is filled with the filler according to any one of claims 1 to 7.   Pipes P are inserted into the sheath pipe A laid in the ground one after another, and the pipes P are joined together to form a pipe P ′. Between the pipe P ′ and the sheath pipe A, the grout material a A double pipe piping structure filled with the filler according to any one of claims 1 to 7.

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