JP2008051183A - Method of rehabilitating existing pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of rehabilitating an existing pipe, which provides sufficient strength only by a back-filling material and a tubular body of a composite pipe without depending on the strength of the existing pipe. <P>SOLUTION: The method for rehabilitating an existing pipe includes: forming a tubular body 30 within the existing pipe 20 by spirally winding a lengthy strip body 50 having joint parts at both side end portions around the existing pipe while mutually bonding the adjacent joint parts; and injecting the back-filling material 40 composed of mortar into a clearance 21 between the inner surface of the existing pipe and the outer surface of the tubular body. The back-filling material 40 contains fiber 41 having an elasticity of 50 GPa or more, and also having a weight ratio of water/cement set at 0.1-0.5, is injected so that the ratio of existing pipe inside diameter/back-filling material thickness is 20-80. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for rehabilitating an existing pipe, in which a tubular body is formed on the inner surface of an aged existing pipe, and then a backfill material is injected and filled into a gap between the existing pipe and the tubular body.

  In particular, the present invention relates to a rehabilitation method for existing pipes using a backfill material containing fibers.

  Existing pipes buried in the ground, such as sewers, waterworks, and gas pipes, will become obsolete due to long-term use, and cracks, corrosion, etc. will occur.

  For this reason, various methods have been proposed for rehabilitating aging existing pipes, and as one of them, adjacent strips are joined together while spirally winding long strips with joints formed on both side edges. By joining the parts together to form a tubular body on the inner surface of the existing pipe and filling and filling the backfill material into the gap formed between the inner surface of the existing pipe and the outer surface of the tubular body, the existing pipe, the backfill material and the tubular body A rehabilitation method for forming a composite pipe is proposed (Patent Document 1).

This existing pipe rehabilitation method can achieve high strength because the composite pipe has a three-layer structure including an existing pipe, a backfill material, and a tubular body.
JP 2003-56745 A

  However, when the strength of the existing pipe is significantly reduced, the strength cannot be ensured with the backfill material and the tubular body of the composite pipe. There is a risk that the composite pipe may be damaged or collapsed by an external force due to the above.

  Therefore, it is common practice to investigate the strength of existing pipes in advance before rehabilitation. On the other hand, when the inner diameter of the existing pipe is too small to accommodate an operator or a large investigation device, a strength investigation is performed using a small investigation device or the like.

  If the above strength survey reveals that the existing pipes are not strong enough, the strength of the composite pipes can be increased by reinforcing the existing pipes before rehabilitation, or by increasing the thickness of the backing material when rehabilitating. However, there is a problem that the construction period is extended by these reinforcements and the construction cost is greatly increased.

  In addition, in a simple survey conducted on existing pipes with small inner diameters, it is difficult to grasp the detailed state of the existing pipes, such as strength and cracks, and leaks from the survey results even though the existing pipes have insufficient strength. There is. In this case, since the existing pipe is rehabilitated without reinforcement, the formed composite pipe becomes insufficient in strength, and the composite pipe is damaged or collapsed due to external force such as earth pressure or earthquake. There was a problem.

  The present invention has been made in view of such circumstances, and the object thereof is not dependent on the strength of the existing pipe, and can be obtained with sufficient strength only with the backfill material and the tubular body of the composite pipe. The purpose is to provide a pipe rehabilitation method.

  In order to solve the above-mentioned problem, the rehabilitation method for an existing pipe according to the present invention joins the adjacent joints to each other while spirally winding a long strip having joints formed on both side edges. In a rehabilitation method for an existing pipe in which a tubular body is formed in the existing pipe, and a backfilling material made of mortar is injected and filled into the gap between the inner surface of the existing pipe and the outer surface of the tubular body, fibers having an elastic modulus of 50 GPa or more are contained. In addition, the backfilling material having a water / cement weight ratio of 0.1 to 0.5 is injected and filled so that the existing pipe inner diameter / backing material thickness ratio is 20 to 80. .

  According to the present invention, the backfilling material containing fibers as described above is injected and filled into the gap between the inner surface of the existing tube and the outer surface of the tubular body, so that the backfilling material and the tubular body of the composite tube Therefore, even if the strength of the existing pipe is low, there is no risk that the composite pipe will be damaged or collapsed by an external force such as earth pressure or earthquake.

  Here, when the elastic modulus of the fiber is less than 50 GPa, the bending crack strength after curing of the back-filling material containing the fiber becomes low, and the back-filling material is easily cracked by an external force. However, when the elastic modulus of the fiber is 50 GPa or more, the bending cracking strength after curing of the backfill material containing the fiber becomes a sufficiently high value, so that there is no possibility that the backfill material is cracked by an external force.

  Further, if the weight ratio of the water / cement of the backfilling material is less than 0.1, the amount of water is too small and it becomes difficult to knead the backfilling material. When the weight ratio exceeds 0.5, the amount of water is too large and the strength of the back-filling material after curing becomes low. However, when the water / cement weight ratio of the backfilling material is in the range of 0.1 to 0.5, kneading is facilitated and the strength of the backfilling material after curing does not decrease.

  Further, if the ratio of the existing pipe inner diameter / backing material thickness is less than 20, the backfilling material layer is formed thicker than the existing pipe, and the inner diameter of the tubular body is reduced. Compared to the amount of treated water in the pipe, the amount of treated water in the composite pipe is extremely reduced, making it difficult to secure a predetermined amount of treated water. On the other hand, if the ratio of the existing pipe inner diameter / backing material thickness exceeds 80, the layer of the backfilling material is formed thinner than the existing pipe, and the layer of the backfilling material reinforced with fibers is compared with the composite pipe. As a result, the composite tube cannot obtain sufficient strength. However, since the backfilling material is injected and filled so that the ratio of the existing pipe inner diameter / backfilling material thickness is 20 to 80, it is not possible to secure a predetermined amount of treated water in the composite pipe or the strength of the composite pipe is insufficient. Nothing happens.

  Further, a tubular body is formed in the existing pipe by joining the adjacent joints adjacent to each other while spirally winding a long strip having joints formed on both side edges, and an inner surface of the existing pipe In the rehabilitation method of an existing pipe in which a backfill material made of mortar is injected and filled in the gap between the outer surface of the tubular body, the fiber is contained in an amount of 0.5 to 5.0 vol%, and the weight ratio of water / cement is 0.1 to 0 The backfilling material set to .5 is injected and filled so that the ratio of the existing pipe inner diameter / backfilling material thickness is 20 to 80.

  According to the present invention, the backfilling material containing fibers as described above is injected and filled into the gap between the inner surface of the existing tube and the outer surface of the tubular body, so that the backfilling material and the tubular body of the composite tube Therefore, even if the strength of the existing pipe is low, there is no risk that the composite pipe will be damaged or collapsed by an external force such as earth pressure or earthquake.

  Here, if the fiber content in the backfilling material is less than 0.5 vol%, the fiber content is too small to obtain the effect of reinforcing the backfilling material with fibers, and the strength of the backfilling material. Does not improve much. Also, if the fiber content in the backfilling material exceeds 5.0 vol%, the fiber content is too high and the viscosity of the backfilling material becomes high, so the gap between the existing pipe inner surface and the outer surface of the tubular body When the backfill material is injected into the substrate, the resistance becomes large and the injection becomes difficult. However, if the fiber content in the backfilling material is in the range of 0.5 to 5.0 vol%, the fiber content is too small and the strength of the backfilling material does not improve so much, There is no case where the fiber content is too high to make it difficult to inject the backfill material 40.

  Further, if the weight ratio of the water / cement of the backfilling material is less than 0.1, the amount of water is too small and it becomes difficult to knead the backfilling material. When the weight ratio exceeds 0.5, the amount of water is too large and the strength of the back-filling material after curing becomes low. However, when the water / cement weight ratio of the backfilling material is in the range of 0.1 to 0.5, kneading is facilitated and the strength of the backfilling material after curing does not decrease.

  Further, if the ratio of the existing pipe inner diameter / backing material thickness is less than 20, the backfilling material layer is formed thicker than the existing pipe, and the inner diameter of the tubular body is reduced. Compared to the amount of treated water in the pipe, the amount of treated water in the composite pipe is extremely reduced, making it difficult to secure a predetermined amount of treated water. On the other hand, if the ratio of the existing pipe inner diameter / backing material thickness exceeds 80, the layer of the backfilling material is formed thinner than the existing pipe, and the layer of the backfilling material reinforced with fibers is compared with the composite pipe. As a result, the composite tube cannot obtain sufficient strength. However, since the backfilling material is injected and filled so that the ratio of the existing pipe inner diameter / backfilling material thickness is 20 to 80, it is not possible to secure a predetermined amount of treated water in the composite pipe or the strength of the composite pipe is insufficient. Nothing happens.

  The fiber may be made of at least one of alkali-resistant glass fiber, carbon fiber, steel fiber, and aramid fiber.

  In this case, since the fiber has a high elastic modulus, the strength of the back-filling material after curing can be remarkably improved by containing the fiber in the back-filling material.

  The rehabilitation method for an existing pipe according to the present invention produces an effect that a sufficient strength can be obtained only with the back-filling material and the tubular body of the composite pipe without depending on the strength of the existing pipe.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 is an explanatory view showing a first step of an existing pipe rehabilitation method in the present embodiment, FIG. 2 and FIG. 3 are a cross-sectional view and a schematic view showing a strip in the present embodiment, and FIG. FIG. 5 is a partial sectional view showing the pipe making machine in the present embodiment, and FIG. 6 is an explanation showing another example of the first step of the existing pipe rehabilitation method in the present embodiment. FIG. 7, FIG. 7 is a schematic diagram showing a pipe making state by the pipe making machine in FIG. 6, FIG. 8 is a side view showing a support apparatus in the present embodiment, and FIG. 9 shows a composite pipe in the present embodiment. It is a side view.

  The rehabilitation method of the existing pipe 20 in the present embodiment includes a first step of forming the tubular body 30 in the existing pipe 20, a second step of fixing the tubular body 30 with the support 70, an existing pipe inner surface and a tubular body. And a third step of injecting and filling the backfill material 40 into the gap 21 with the outer surface.

  In addition, the rehabilitation method of the existing pipe 20 in this Embodiment is good to use when the viscosity of the backfilling material 40 is comparatively low, for example, the content rate of the fiber 41 is the range of 0.5-2.0 vol%. Since the backfilling material 40 has high fluidity and low viscosity, the filling and filling can be smoothly performed by this rehabilitation method even in the gap 21 between the existing pipe inner surface and the tubular body outer surface having a large volume.

  First, as shown in FIG. 1, a first step of forming a tubular body 30 in the existing pipe 20 is performed.

  The existing pipe 20 has various shapes such as a circular shape, a rectangular shape, and a horseshoe shape as a cross-sectional shape. In the present embodiment, an example in which the existing pipe 20 having a circular cross-sectional shape is regenerated is shown. .

  First, the drum 84 around which the belt-like body 50 (see FIGS. 2 and 3) is wound is installed on the ground or in the existing pipe 20. Thereafter, as shown in FIG. 1, the belt-like body 50 is continuously supplied from the drum 84 to a self-propelled pipe making machine 60 (see FIGS. 4 and 5) disposed in the existing pipe 20. While the strip-shaped body 50 is spirally wound by the pipe making machine 60, the joint portions at both side edges of the strip-shaped bodies 50 adjacent to each other are joined to each other, and the tubular body 30 is formed in the direction indicated by the arrow in FIG. Can be formed.

  As long as the said strip | belt-shaped body 50 is a long thing by which the junction part was formed in the both-sides edge part, it does not specifically limit a shape, For example, as shown to Fig.2 (a), and A thing as shown to Fig.3 (a) etc. is used.

  The former strip 50 shown in FIG. 2A has a plurality of ribs 53... 53 formed along the longitudinal direction, and is joined to both side edges overlapping with each other inside and outside. The convex part 51 and the joining recessed part 52 are formed along the longitudinal direction. As shown in FIG. 2B, a reinforcing member 54 is provided between the two ribs 53 of the strip-like body 50 shown in FIG. 2A in order to ensure the strength of the tubular body 30 after pipe production. It may be provided.

  On the other hand, the latter strip 50 shown in FIG. 3A is a combination of a main strip member 501 and a fitting member 502, and the main strip member 501 has a plurality of ribs 53. Are formed along the longitudinal direction. Further, the fitting member 502 is provided with a joint convex portion 51 that is elastically fitted to the joint concave portion 52 of the main belt-like member 501. Accordingly, when the band-like body 50 is joined, as shown in FIG. 3B, the fitting member 502 is fitted over the joining recesses 52 and 52 of the adjacent main band-like members 501 and 501. The main strip members 501 and 501 adjacent to each other can be connected to each other. A reinforcing member (not shown) may be provided between the two ribs 53 of the main belt-like member 501 in order to ensure the strength of the tubular body 30 after pipe production.

  In addition, the material of the strip 50 is not particularly limited as long as it is a synthetic resin, and examples thereof include hard vinyl chloride, polyethylene, and polypropylene.

  As shown in FIGS. 4 and 5, the pipe making machine 60 is a self-propelled pipe making machine 60 used for construction of the tubular body 30 having a circular cross section, and is installed on the forming frame 61 and the forming frame 61. And a joining mechanism portion 62. The joining mechanism portion 62 includes an outer roller 63 and an inner roller 64 for sandwiching the belt-like body 50 from both the outer surface and the inner surface. The rotation of the outer surface roller 63 and the inner surface roller 64 causes the entire pipe making machine 60 to move around the existing tube 20 and advance while spirally winding the belt-like body 50. The joint convex part 51 and the joint concave part 52 of the body 50 can be joined to each other.

  The inner roller 64 is driven by hydraulic oil supplied from a hydraulic unit 81 (see FIG. 1). The hydraulic unit 81 is driven by electric power supplied from a generator 82 (see FIG. 1).

  Note that the first step of the present embodiment is not limited to the formation of the tubular body 30 using the self-propelled pipe making machine 60 as described above. For example, as shown in FIG. It may be performed using a pipe making machine 60 that is fixed to the open end of the pipe 20. In this case, the first step is performed as follows.

  First, the drum 84 around which the belt-like body 50 (see FIGS. 2 and 3) is wound is installed on the ground or in the existing pipe 20. After that, as shown in FIG. 6, the belt-like body 50 is continuously supplied from the drum 84 to the fixed type pipe making machine 60 arranged so as to face the opening end of the existing pipe 20. The strip-shaped body 50 is spirally wound by the pipe making machine 60, and joint portions at both side edges of the strip-shaped bodies 50 adjacent to each other are joined together to form the tubular body 30. At that time, the tubular body 30 formed and led out by the pipe making machine 60 is directly introduced into the existing pipe 20 and is propelled in the direction of the arrow in FIG. 6 while rotating in the existing pipe 20. The tubular body 30 is formed in the inside 20.

  As shown in FIG. 7, the pipe making machine is configured so that the belt-like body 50 to be introduced is spirally wound in the direction of the arrow in the figure by the pipe-making roller 65, and both sides of the belt-like bodies 50, 50 adjacent to each other. By joining the joint portions of the edge portions to each other, the tubular body 30 is sequentially formed, and the tubular body 30 is further pushed into the existing tube 20.

  Next, as shown in FIG. 8, a second step of fixing the tubular body 30 with the support work 70 is performed.

  The support 70 is for fixing the tubular body 30 from the inside in order to prevent the tubular body 30 from being lifted when the backfill material 40 is injected and filled in a third step to be described later. The support work 70 is not particularly limited. For example, a support work 70 as shown in FIG. 8 can be used. The support 70 shown in FIG. 8 includes a frame 71, an advancing and retracting rod 72 extending radially from each side of the frame 71, an abdominal erection member 73 attached to the tip of the advancing and retracting 72, and a frame And a reaction force member 74 extending vertically upward from the upper side of 71.

  Next, a third step of injecting and filling the backfill material 40 into the gap 21 between the existing pipe inner surface and the tubular body outer surface is performed.

  The filling and filling of the backfill material 40 is performed by providing a plurality of injection holes (not shown) in the tubular body 30 and filling and filling the backfilling material 40 into the gap 21 between the inner surface of the existing tube and the outer surface of the tubular body through the injection holes. .

  The backfill material 40 contains fibers 41 having an elastic modulus of 50 GPa or more and has a water / cement weight ratio of 0.1 to 0.5, or fibers 41 of 0.5 to 5. A material containing 0 vol% and having a water / cement weight ratio of 0.1 to 0.5 is used.

  By filling and filling these backfilling materials 40 into the gap 21 between the inner surface of the existing pipe and the outer surface of the tubular body, high strength can be obtained only by the backfilling material 40 and the tubular body 30 in the composite pipe 10. Even if the strength of the existing pipe 20 is low, there is no possibility that the composite pipe 10 is broken or collapsed by an external force such as earth pressure or earthquake.

  Here, as described above, the former backfilling material 40 contains fibers 41 having an elastic modulus of 50 GPa or more and a water / cement weight ratio of 0.1 to 0.5.

  If the elastic modulus of the fiber 41 is less than 50 GPa, the bending crack strength after curing of the backfilling material 40 containing the fiber 41 becomes low, and the backfilling material 40 is easily cracked by an external force. . However, if the elastic modulus of the fiber 41 is 50 GPa or more, the bending crack strength after curing of the backfilling material 40 containing the fiber 41 becomes a sufficiently high value, so that the backfilling material 40 is cracked by an external force. There is no fear.

  Further, if the water / cement weight ratio of the backfill material 40 is less than 0.1, the amount of water is too small to make it difficult to knead the backfill material 40, while the water in the backfill material 40 If the weight ratio of / cement exceeds 0.5, the amount of water is too large and the strength of the back-filling material 40 after curing will be low. However, when the water / cement weight ratio of the backfilling material 40 is in the range of 0.1 to 0.5, kneading is facilitated and the strength of the backfilling material 40 after curing does not decrease. .

  On the other hand, as described above, the latter backfilling material 40 contains 0.5 to 5.0 vol% of the fiber 41 and has a water / cement weight ratio of 0.1 to 0.5.

  If the content of the fiber 41 in the backfilling material 40 is less than 0.5 vol%, the content of the fiber 41 is too small and the effect of reinforcing the backfilling material 40 with the fiber 41 cannot be obtained so much. The strength of the embedding material 40 is not improved so much. Further, if the content of the fiber 41 in the backfilling material 40 exceeds 5.0 vol%, the content of the fiber 41 is too large and the viscosity of the backfilling material 40 becomes high. When the backfilling material 40 is injected into the gap 21 with the outer surface, the resistance is large and the injection becomes difficult. However, when the content of the fiber 41 in the backfilling material 40 is in the range of 0.5 to 5.0 vol%, the content of the fiber 41 is too small, and the strength of the backfilling material 40 is hardly improved. In addition, there is no case where the content of the fiber 41 is excessive and injection of the backfill material 40 becomes difficult.

  Further, as described above, when the water / cement weight ratio of the backfill material 40 is in the range of 0.1 to 0.5, kneading is facilitated, and the strength of the backfill material 40 after curing is reduced. There is no such thing as to do.

  The backfill material 40 contains 0.5 to 5.0 vol% of fibers 41 having an elastic modulus of 50 GPa or more and a water / cement weight ratio of 0.1 to 0.5. May be. Since such a backfilling material has the advantages of the former backfilling material 40 and the latter backfilling material 40, the formed composite pipe 10 can obtain higher strength.

  The backfilling material 40 is injected and filled into the gap 21 between the existing tube inner surface and the tubular body outer surface so that the ratio of the existing tube 20 inner diameter / backing material 40 thickness is 20-80.

  If the ratio of the existing tube 20 inner diameter / backfilling material 40 thickness is less than 20, the layer of the backfilling material 40 is formed thicker than the existing tube 20 and the inner diameter of the tubular body 30 is reduced. Therefore, compared to the original treated water amount of the existing pipe 20, the treated water amount of the composite pipe 10 is extremely reduced, and it becomes difficult to secure a predetermined treated water amount. On the other hand, when the ratio of the inner diameter of the existing pipe 20 / the thickness of the backfilling material 40 exceeds 80, the layer of the backfilling material 40 is formed thin with respect to the existing pipe 20, and the backfilling material 40 reinforced with the fibers 41 is formed. Since the layer becomes too thin with respect to the composite tube 10, the composite tube 10 cannot obtain sufficient strength. However, since the backfilling material 40 is injected and filled so that the ratio of the existing pipe 20 inner diameter / backfilling material 40 thickness is 20 to 80, a predetermined amount of treated water in the composite pipe 10 cannot be secured, or the composite pipe 10 There will be no shortage of strength.

  In addition, as the fiber 41 contained in the backfill material 40, it is preferable to use a fiber having an aspect ratio of 50 or more, a diameter of 8 to 500 μm, and a length of 2 to 50 mm.

  If the aspect ratio of the fiber 41 is less than 50, the fiber 41 becomes thick and short, and the elasticity of the fiber 41 may be lost. I can't expect much improvement. However, when the aspect ratio of the fibers 41 is 50 or more, the fibers 41 are thin and long and have sufficient elasticity, so that the strength of the backfilling material 40 containing the fibers 41 can be improved.

  Further, when the backfilling material 40 containing the fibers 41 is kneaded when the diameter of the fibers 41 is less than 8 μm, the fibers 41 are easily entangled with each other, so that the fibers 41 are uniformly dispersed in the backfilling material 40. It is difficult to make the strength of the backfilling material 40 uniform. On the other hand, when the diameter of the fiber 41 exceeds 500 μm, the adhesiveness between the mortar of the backfilling material 40 and the fiber 41 is lowered. Therefore, when an external force is applied to the backfilling material 40 containing the fiber 41, The mortar slips at the interface, and the effect of improving the strength of the backfilling material 40 is reduced. However, when the diameter of the fiber 41 is in the range of 8 to 500 μm, the fiber 41 is not too thin to be uniformly dispersed in the backfill material 40, and is too thick to adhere the mortar to the fiber 41. There will be no decline.

  Moreover, since the fiber 41 is too small as the length of the fiber 41 is less than 2 mm, even if it is contained in the backfilling material 40, the effect of reinforcing the backfilling material 40 with the fiber 41 cannot be obtained. On the other hand, when the length of the fiber 41 exceeds 50 mm, the fibers 41 are easily entangled when the backfilling material 40 containing the fiber 41 is kneaded. Therefore, the fibers 41 are uniformly dispersed in the backfilling material 40. It is difficult to make the strength of the backfilling material 40 uniform. However, when the length of the fiber 41 is in the range of 2 to 50 mm, it is not too short and it is difficult to obtain the effect of reinforcing the fiber, and the fiber 41 is uniformly dispersed in the backfilling material 40 because it is too long. It's not difficult.

  Further, the cement used for the mortar of the backfill material 40 is not particularly limited. For example, Portland cement such as ordinary Portland cement, early-strength Portland cement, ultra-early strong Portland cement, and moderately hot Portland cement, and Examples include mixed cements such as blast furnace cement and silica cement.

  As the fiber 41, it is preferable to use at least one of alkali-resistant glass fiber, carbon fiber, steel fiber, and aramid fiber. In this case, since the fiber 41 has a high elastic modulus, the strength of the back-filling material 40 after curing can be remarkably improved by containing the fiber 41 in the back-filling material 40.

  In particular, the alkali-resistant glass fiber 41 is most suitable in terms of adhesion to mortar and rust prevention as compared with carbon fiber, steel fiber, and aramid fiber. However, carbon fiber, steel fiber, and aramid fiber can also be obtained by coating the surface with a sizing agent to obtain properties such as adhesion to mortar equivalent to alkali-resistant glass fiber and rust prevention.

  Note that when the water / cement weight ratio is decreased (the amount of water is reduced) in order to improve the strength of the backfilling material 40, the flowability can be increased by adding a water reducing agent. Workability such as kneading and injection filling can be improved.

  The water reducing agent is not particularly limited, and examples thereof include lignin sulfonic acid type, naphthalene sulfonic acid type, melamine sulfonic acid type, polycarboxylic acid type and amino sulfonic acid type. The water reducing agent is usually added in the range of 0.5 to 5.0% by weight with respect to the cement.

Further, the backfilling material 40 includes admixtures such as fly ash, blast furnace slag and silica fume for suppressing hydration heat generation of cement, and CaO, 3CaO.Al ² O ³ .CaSO for suppressing shrinkage during cement hardening. ⁴ and ^{6CaO · Al 2 O 3 · SO} 3 -CaO expansion material, such as may be added. When the admixture and the expansion material are added to the backfill 40 as described above, the water / cement weight ratio is calculated by using the admixture and the expansion material as a cement component.

  Further, the backfill material 40 may be mixed with a separation reducing agent, an aggregate, a polymer dispersion, and the like. Examples of the separation reducing agent include methyl cellulose, polyvinyl alcohol, hydroxyl alcohol, sodium polyacrylate and polyacrylamide, and examples of the aggregate include quartz sand, river sand and crushed stone powder. Examples of the polymer dispersion include acrylics, vinyl acetates, ethylene vinyl acetates, and styrene / butadiene rubbers.

  Finally, after the backfilling material 40 filled in the gap 21 between the inner surface of the existing pipe and the outer surface of the tubular body is hardened to some extent, the supporting work provided inside the tubular body 30 is removed to rehabilitate the existing pipe 20. Ends (see FIG. 9).

  Next, a modified example of the existing pipe rehabilitation method in the present embodiment will be described with reference to FIGS.

  FIG. 10 is an explanatory view showing a rehabilitation method for an existing pipe in this modification, FIG. 11 is a side view showing the pipe making machine in this modification, and FIG. 12 is a partial sectional view showing the pipe making machine in this modification. is there.

  The rehabilitation method for the existing pipe 20 according to the present modification is that a gap 21 between the inner surface of the existing pipe and the outer surface of the tubular body is formed while the tubular body 30 is formed in the existing pipe 20 by the pipe making machine 60 installed in the existing pipe 20. The backfill material 40 is injected and filled by inserting the injection nozzle 65 of the pipe making machine 60.

  In addition, the rehabilitation method of the existing pipe 20 in this modification is good to use when the viscosity of the backfilling material 40 is comparatively high, for example, the back of the range whose content rate of the fiber 41 is 2.0-5.0 vol%. Since the filling material 40 has low fluidity and high viscosity, the filling material 40 is not suitable for pouring and filling the gap 21 between the existing pipe inner surface and the outer surface of the tubular body having a large volume. It is good to perform the construction method. Further, even in the case of the backfilling material 40 having a fiber 41 content of 0.5 to 2.5 vol%, it is possible to increase the viscosity by adding a separation reducing agent. The rehabilitation method for the existing pipe 20 can be used.

  The rehabilitation method for the existing pipe 20 will be described in detail. First, a drum 84 on which the belt-like body 50 is wound in advance is installed on the ground or in the existing pipe 20, and then the self-propelled pipe making arranged in the existing pipe 20 is performed. The belt-like body 50 is continuously supplied from the drum 84 to the machine 60, and the belt-like body 50 is spirally wound by the pipe making machine 60, and the joint portions 51, 52 at both side edges of the belt-like bodies 50 adjacent to each other. The tubular body 30 is formed in the existing pipe 20 by fitting each other. Then, the backfilling material 40 is supplied from the backfilling material supply machine 67 to the injection nozzle 65 provided in the pipe making machine 60, and simultaneously with the formation of the tubular body 30, the inner surface of the existing pipe and the outer surface of the tubular body are supplied from the injection nozzle 65. The backfill material 40 is injected into the gap 21.

  According to this construction method, since the backfilling material 40 is sealed simultaneously with the formation of the tubular body 30, the installation and removal of the support work 70 is unnecessary, rapid construction is possible, and man-hours more than necessary for construction are required. It does not take. Moreover, since it is possible to form the tubular body 30 so that it may affix on the whole circumference of the existing pipe 20, the tubular body 30 has very little cross-sectional reduction after rehabilitation. Furthermore, there is an advantage that the construction speed is fast and the process is simplified.

  As shown in FIGS. 11 and 12, the pipe making machine 60 is one in which an injection nozzle 65 and a hose 66 are provided in the pipe making machine 60 shown in FIGS. 3 and 4.

  As shown in FIG. 10, the backfilling material supplier 67 pushes out the backfilling material 40 by a certain amount, and the amount of extrusion can be arbitrarily adjusted. This backfilling material supply machine 67 is mounted on a carriage 83 and is connected to an injection nozzle 65 of the pipe making machine 60 via a hose 66.

  As shown in FIG. 10, the carriage 83 is equipped with a backfilling material supply machine 67 and a hydraulic unit 81, and as indicated by an arrow in the figure, the tubular body 30 is formed in the existing pipe 20 together with the pipe making machine 60. It is moved in the forming direction. However, the backfilling material supply machine 67 may be fixedly arranged on the ground.

  Table 1 shows an example and a comparative example when the bending strength test was performed on the backfill material 40 of the present embodiment.

ここで、実施例及び比較例において、セメントは普通ポルトランドセメント又はＢ種高炉セメントを用い、また、繊維４１は長さ６ｍｍで直径１８μｍの耐アルカリガラス繊維のチョップドストランドを用いた。また、実施例及び比較例の試験体は、オムニミキサーにより作製し、２８日後における試験体に対して曲げ強度試験を行った。

Here, in Examples and Comparative Examples, ordinary Portland cement or B-type blast furnace cement was used as the cement, and chopped strands of alkali-resistant glass fibers having a length of 6 mm and a diameter of 18 μm were used as the fibers 41. Moreover, the test body of an Example and a comparative example was produced with the omni mixer, and the bending strength test was done with respect to the test body in 28 days.

  In Comparative Example 1, the backfill material 40 does not contain any fibers 41. In Comparative Example 2, the water / cement weight ratio is 0.65, and the water / cement of the present invention is used. The weight ratio was greatly exceeded.

  The backfilling material 40 of all the examples was able to obtain a bending strength nearly four times that of the backfilling material 40 of the comparative example.

It is explanatory drawing which shows the 1st process of the rehabilitation method of the existing pipe | tube in this invention. It is sectional drawing which shows the strip | belt-shaped body in this invention. It is the schematic which shows the other example of the strip | belt-shaped body in this invention. It is a side view which shows the pipe making machine in this invention. It is a fragmentary sectional view showing the pipe making machine in the present invention. It is explanatory drawing which shows the other example of the 1st process of the rehabilitation method of the existing pipe | tube in this invention. It is a schematic diagram which shows the pipe making state by the pipe making machine in FIG. It is a side view which shows the support work apparatus in this invention. It is a side view which shows the composite pipe | tube in this invention. It is explanatory drawing which shows the modification of the rehabilitation method of the existing pipe in this invention. It is a side view which shows the pipe making machine in a modification. It is a fragmentary sectional view showing a pipe making machine in a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Composite pipe 20 Existing pipe 21 Clearance 30 between existing pipe inner surface and tubular body outer surface Tubular body 40 Back-filling material 41 Fiber 50 Band-shaped body

Claims (3)

A tubular body is formed in an existing pipe by joining the adjacent joints to each other while spirally winding a long strip having joints formed on both side edges, and the inner surface of the existing pipe and the tubular body In the rehabilitation method of existing pipes that inject and fill backfilling material consisting of mortar into the gap with the outer surface,
A backfilling material containing fibers having an elastic modulus of 50 GPa or more and a water / cement weight ratio of 0.1 to 0.5, and an existing pipe inner diameter / backing material thickness ratio of 20 to 80 A rehabilitation method for existing pipes, which is characterized by filling and filling. A tubular body is formed in an existing pipe by joining the adjacent joints to each other while spirally winding a long strip having joints formed on both side edges, and the inner surface of the existing pipe and the tubular body In the rehabilitation method of existing pipes that inject and fill backfilling material consisting of mortar into the gap with the outer surface,
A backfilling material containing 0.5 to 5.0 vol% of fiber and having a water / cement weight ratio of 0.1 to 0.5 is used, and the existing pipe inner diameter / backing material thickness ratio is 20 to 80. An existing pipe rehabilitation method characterized by filling and filling so that   The method for rehabilitating an existing pipe according to claim 1 or 2, wherein the fiber comprises at least one of alkali-resistant glass fiber, carbon fiber, steel fiber, and aramid fiber.

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