Rehabilitation method and structure of existing pipes

Abstract

To provide a method for rehabilitation of existing pipes and a rehabilitation structure that is easy to remove when rehabilitation is required again, such as after the useful life of the pipe has passed.SOLUTION: A peeling coating material 5 composed of a coating material or sheet is provided on the inner surface of an aged existing pipe 2. Then, a first rehabilitation material 3 made mainly of synthetic resin is provided in a tubular form along the inner surface of the existing pipe 2. Between the peeling coating material 5 and the first rehabilitation material 3 on the inner surface of the existing pipe 2, a fillable second rehabilitation material 4 is provided.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method and structure for rehabilitating existing pipes such as aging sewer pipes, and particularly to a method and structure for rehabilitating existing pipes by providing a rehabilitation material along the inner surface of the existing pipe.

Background Art

[0002] When existing pipes such as sewer pipes buried underground are aged, the existing pipes are rehabilitated by providing a rehabilitation material formed into a tubular shape (hereinafter appropriately referred to as a "rehabilitation pipe") on the inner surface of the existing pipe (see Patent Document 1, etc.). This type of rehabilitation method includes a composite pipe method in which the existing pipe, the rehabilitation pipe, and the mortar are integrated through backfill mortar and bear strength together, and a self-supporting pipe method in which the rehabilitation pipe bears strength alone.

[0003] In the composite pipe method, strength design is performed based on the strengths of the three components of the existing pipe, the rehabilitation pipe, and the mortar. For strength expression, the adhesion at the interface between the mortar and the existing pipe is the key point for strength expression. In cases where the strength of the existing pipe has extremely decreased, strength calculation may be performed based on the strengths of only the rehabilitation pipe and the mortar without considering the strength of the existing pipe.

[0004] Even in the self-supporting pipe method, similar to the composite pipe method, mortar may be backfilled between the existing pipe and the rehabilitation pipe. In this case, the mortar is for the purpose of filling voids. Therefore, the strength of the mortar may be about the strength of the ground (soil strength).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0033] )

Summary of the Invention

Problems to be Solved by the Invention

[0006] Currently, pipeline rehabilitation methods have made significant progress and are seeing increased construction track record. However, the rehabilitated pipelines themselves also have a service life, which is currently considered to be 50 years with current technology. After the service life has expired, pipeline rehabilitation will be required again. As for methods of re-rehabilitation, for example, (1) A method of installing a new rehabilitation pipe and mortar inside the old rehabilitation pipe. (2) A method of removing the old rehabilitation pipe and mortar and installing a new rehabilitation pipe and mortar. That is a possibility.

[0007] In method (1), the inner diameter of the new rehabilitated pipe becomes smaller, which reduces its flow performance. In method (2), the old mortar is crushed and removed using a breaker or the like, but usually the existing pipe and mortar are firmly adhered to each other, making it difficult to separate and remove the rehabilitated pipe and mortar at the interface with the existing pipe. In view of these circumstances, the present invention aims to provide an existing pipe rehabilitation method and rehabilitation structure that can be easily removed when rehabilitation is required again, such as when the service life has expired. [Means for solving the problem]

[0008] To solve the aforementioned problems, the present invention provides a method for rehabilitating an existing pipe, wherein a first rehabilitation material mainly composed of synthetic resin is provided in a tubular shape along the inner surface of the existing pipe, and a second filling rehabilitation material is provided between the inner surface of the existing pipe and the first rehabilitation material, The method is characterized by providing a peeling coating material, consisting of a coating material or a sheet, on the inner surface of the existing pipe before providing the first and second rehabilitation materials. The present invention provides a pipe rehabilitation structure in which a tubular first rehabilitation material mainly made of synthetic resin is provided along the inner surface of the existing pipe, and a second rehabilitation material is filled between the inner surface of the existing pipe and the first rehabilitation material. A peeling coating material, consisting of a coating material or a sheet, is provided between the inner surface of the existing pipe and the second rehabilitation material.

[0009] By installing a release coating on the inner surface of the existing pipe (the interface between the existing pipe and the second rehabilitation material) before the application of the first and second rehabilitation materials, adhesion (integration) between the second rehabilitation material and the existing pipe can be prevented. Therefore, when pipe rehabilitation is performed again after the service life has expired, the first and second rehabilitation materials can be easily removed. In particular, this is an effective means of facilitating removal after the service life has expired for rehabilitation methods that do not rely on the strength of the existing pipe. Existing pipes can take various shapes, including circular, rectangular, and horseshoe-shaped pipes. The main material occupies preferably 50% or more, more preferably 60% or more, of the cross-sectional area of ​​the cross-section of the first rehabilitated material. Examples of the first rehabilitation material include strip-shaped members (profiles) mainly made of synthetic resin, tubes made of resin or resin-impregnated fibers, sheath tubes, segments, plate-shaped materials made of fiber-reinforced resin, etc. The tubular first rehabilitation material that runs along the inner surface of the existing pipe may be a spiral pipe made by winding a strip-shaped member in a spiral shape, a resin tube or resin-impregnated fiber tube installed along the inner surface of the existing pipe by an inversion method or a forming method, one or more conduit pipes connected in a line in the direction of the pipe axis, or multiple segments or plate-shaped materials combined in the direction of the pipe circumference and the direction of the pipe axis to form a tubular shape. The cross-sectional shape of the first rehabilitation material, which is formed in a tubular shape, is not limited to circular; it may also be rectangular, horseshoe-shaped, or any other shape. The filling properties of the second rehabilitation material refer to the ability of the second rehabilitation material to be injected and fill (fill) the gap between the inner surface of the existing pipe and the tubular first rehabilitation material. The second rehabilitation material only needs to have fluidity for injection and may harden after injection. Preferably, the hardened second rehabilitation material has a strength of about the same as or greater than the ground strength (compressive strength of about 0.5 MPa). From a cost standpoint, mortar is preferred as the material of the second rehabilitation material, but it is not limited to mortar and may also be a resin-based material, a foamed material, etc.

[0010] Preferably, in the existing pipe rehabilitation structure, the peeling coating material is easily peelable from either the existing pipe or the second rehabilitation material. Easy peelability refers to the fact that the coating material can be easily peeled off from the existing pipe or the second rehabilitation material. Preferably, the adhesion strength between the existing pipe and the second rehabilitation material and the peeling coating material is lower than the tensile strength of the existing pipe and the second rehabilitation material itself. For example, if the existing pipe is made of concrete, the compressive strength of typical concrete is about 18 MPa to 36 MPa, and the tensile strength is about one-tenth of the compressive strength, i.e., about 1.8 MPa to 3.6 MPa. Therefore, it is preferable that the adhesion strength between the concrete existing pipe and the peeling coating material is 1.8 MPa to 3.6 MPa or less. However, considering cases where the existing pipe is aging and its compressive and tensile strengths have decreased, it is preferable that the adhesion strength between the existing pipe and the peeling coating material is lower than 1.8 MPa to 3.6 MPa. Furthermore, the compressive strength of the backfill mortar used as the second rehabilitation material in this type of existing pipe rehabilitation structure is approximately 1.0 MPa to 2.0 MPa, and its tensile strength is approximately one-tenth of the compressive strength, i.e., approximately 0.1 MPa to 0.2 MPa. Therefore, it is preferable that the adhesion strength between the second rehabilitation material, which is made of mortar, and the peeling coating material be approximately 0.1 MPa to 0.2 MPa or less. Either the adhesion strength between the existing pipe and the peeling coating is lower than the tensile strength of the existing pipe itself, or the adhesion strength between the second rehabilitation material and the peeling coating is lower than the tensile strength of the second rehabilitation material itself.

[0011] Preferably, the release coating material consisting of a coating agent is a coating film mainly composed of silicone or fluorine, but the main ingredients are not limited to these, and it is sufficient if it is releaseable from the material of the existing pipe (concrete, iron, or resin (such as polyvinyl chloride (PVC))) or from the material of the second rehabilitation material (hardened mortar, resin, etc.). When a coating material is used as a peeling coating material, the application method involves applying the coating material to the inner surface of the existing pipe in advance. After the coating film is formed, the first and second rehabilitation materials are applied. Therefore, no special techniques or application methods are required. Methods for applying the coating material include spraying with a sprayer and hand application with a roller. The application area is preferably the entire circumference of the inner surface of the existing pipe, but it may also be applied in a spiral pattern or grid pattern along the inner surface of the existing pipe, leaving some areas uncoated. In the uncoated areas, the second rehabilitation material adheres in direct contact with the inner surface of the existing pipe, but it can be peeled off along with the coated portion of the coating material.

[0012] As the release coating material consisting of a sheet, for example, polyethylene (PE), PVC sheet, or other resin-based sheet can be used. Preferably, a general-purpose resin sheet with low cost is used, but it is not necessarily limited to this. A sheet with a mesh structure, such as a mesh, may also be used as the release coating material. In the case of a sheet with a mesh structure, the second rehabilitation material can adhere directly to the inner surface of the existing pipe through the mesh holes, but when the sheet is peeled off, the adhesion portion of the mesh holes can also be peeled off along with it. Preferably, the peel-off coating, which is made of a sheet, is easily peelable from the second rehabilitation material, and the second rehabilitation material does not easily adhere to it. The sheet thickness is preferably around 0.1 mm to 2 mm, but is not limited to this. The sheet size is preferably such that it can be installed by hand, for example, a rectangle with sides of about 1 to 2 m is preferred, but is not limited to this, and a long sheet with a width of 1 to several m is also acceptable. When using a sheet as a peeling coating material, the installation method involves pre-fixing the sheet to the inner surface of the existing pipe using fixing means such as concrete screws or anchors. Preferably, the sheet is installed around the entire circumference of the inner surface of the existing pipe. After the sheet is installed, the first and second rehabilitation materials are applied. Therefore, no special techniques or construction methods are required.

[0013] Preferably, the first rehabilitating material includes a metal reinforcing material. As a result, the strength of the first recycled material is increased, and the strength as a self-supporting pipe can be ensured. There is no need to design it as a composite pipe, and there is no problem even if a peeling coating material is interposed between the existing pipe and the second recycled material. As the material of the metal reinforcing material, steel with excellent ductility is preferable in consideration of deformation occurring along the inner surface of the existing pipe during construction, but it is not necessarily limited to this.

Advantages of the Invention

[0014] According to the present invention, when recycling is required again after the service life has passed, etc., the first recycled material and the second recycled material can be easily peeled off from the inner surface of the existing pipe and removed.

Brief Description of the Drawings

[0015] [Figure 1] FIG. 1 is a cross-sectional view of an existing pipe recycling structure according to a first embodiment of the present invention. [Figure 2] FIG. 2(a) is a cross-sectional view showing a strip-shaped member constituting the first recycled material in the existing pipe recycling structure in a cross-section orthogonal to the strip length direction. FIG. 2(b) is a cross-sectional view of a joint portion of adjacent edge portions of the strip-shaped member in a spiral tubular first recycled material formed from the strip-shaped member with a one-week difference. [Figure 3] FIG. 3 is a cross-sectional view of an existing pipe recycling structure according to a second embodiment of the present invention.

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. <First Embodiment (FIGS. 1 to 2)> As shown in Figure 1, the existing pipe rehabilitation structure 1 according to the first embodiment of the present invention comprises an existing pipe 2, a first rehabilitation material 3, a second rehabilitation material 4, and a peeling coating material 5. The existing pipe 2 is a sewer pipe buried underground and is made of, for example, a reinforced concrete Hume pipe. Note that the existing pipe 2 is not limited to a sewer pipe, but may also be a water supply pipe, gas pipe, agricultural water pipe, hydroelectric power generation water conduit, tunnel, etc. The material of the existing pipe 2 is not limited to reinforced concrete, but may also be unreinforced concrete, synthetic resin, fiber-reinforced resin, etc., or metal such as iron. The cross-sectional shape of the existing pipe 2 is, for example, circular, but is not limited to this, and may also be rectangular, horseshoe-shaped, etc.

[0017] As shown in Figure 1, a first rehabilitation material 3 is provided inside the existing pipe 2. As shown in Figure 2(a), the first rehabilitation material 3 is composed of, for example, a strip-shaped member 10 (profile). The strip-shaped member 10 includes a main strip body 11 and a reinforcing material 20, and is formed in a certain cross-sectional shape. The strip body 11 is made of a synthetic resin such as polyvinyl chloride (PVC). Male and female fitting parts 13 and 14 are provided at both edges in the width direction of the flat strip portion 12 of the strip body 11, and a rib 15 is provided in the middle part in the width direction. Note that the cross-sectional shape of the strip body 11 and thus the strip-shaped member 10 is not limited to the shape shown.

[0018] A reinforcing member 20 is attached to the main body of the strip 11. The reinforcing member 20 is made of metal, preferably highly ductile steel. The reinforcing member 20 includes a body portion 21 with a box-shaped or U-shaped cross-section that opens toward the flat strip portion 12, and a pair of arm portions 22 connected to both ends of the body portion 21. The arm portions 22 are locked to the rib 15. Note that the cross-sectional shape of the reinforcing member 20 is not limited to the shape shown. The reinforcing member 20 may be formed in a flat plate shape and embedded inside the rib 15 of the main body of the strip 11, etc.

[0019] As shown in Figures 1 and 2(b), the strip-shaped member 10 is wound spirally along the inner surface of the existing pipe 2, and the fitting portions 13 and 14 of the adjacent edges of the strip-shaped member 10, offset by one full turn, are joined together by a concave-concave fitting. As a result, as shown in Figure 1, the first rehabilitation material 3 is in a spiral tubular shape (tubular shape) that follows the inner surface of the existing pipe 2. The cross-sectional shape of the first rehabilitation material 3 is circular, matching the cross-section of the existing pipe 2. Furthermore, it is preferable that the cross-section of the first rehabilitation material 3 be rectangular when the cross-section of the existing pipe 2 is rectangular, and that the cross-section of the first rehabilitation material be horseshoe-shaped when the cross-section of the existing pipe 2 is horseshoe-shaped.

[0020] As shown in Figure 1, the second rehabilitation material 4 is filled between the inner surface of the existing pipe 2 and the first rehabilitation material 3. The second rehabilitation material 4 is made of mortar. The mortar has fluidity (filling properties) when injected during the rehabilitation of the existing pipe, and then hardens. The compressive strength of the mortar after hardening is preferably about the ground strength (about 0.5 MPa) or higher, and the tensile strength is, for example, about one-tenth of the compressive strength. More preferably, the compressive strength of the mortar after hardening is about 1.0 MPa to 2.0 MPa, and the tensile strength is about 0.1 MPa to 0.2 MPa.

[0021] As shown in Figure 1, a peeling coating material 5 is interposed between the inner surface of the existing pipe 2 and the second rehabilitation material 4. Therefore, the entire or at least a portion of the inner surface of the existing pipe 2 is in direct contact with the peeling coating material 5, but not in direct contact with the second rehabilitation material 4. The release coating material 5 consists of a coating material. Examples of coating materials include paints mainly composed of silicone or fluorine, but are not limited to these as long as they have the required release properties.

[0022] The release coating material 5 is easily detachable from the concrete constituting the inner surface of the existing pipe 2, or from the hardened mortar constituting the second rehabilitation material 4. Preferably, the adhesion strength between the existing pipe 2 and the release coating material 5 is lower than the tensile strength of the deteriorated existing pipe 2 itself. Preferably, the adhesion strength between the concrete existing pipe 2 and the release coating material 5 is about 1.8 MPa to 3.6 MPa or less, and considering the case where the deterioration of the existing pipe 2 has progressed, it is more preferable that the adhesion strength between the existing pipe 2 and the release coating material 5 is lower than about 1.8 MPa to 3.6 MPa.

[0023] Alternatively, the adhesion strength between the second rehabilitation material 4 and the peeling coating material 5 is lower than the tensile strength of the second rehabilitation material 4 itself. Preferably, the adhesion strength between the second rehabilitation material 4 and the peeling coating material 5 is about 0.1 MPa to 0.2 MPa or less.

[0024] The aging existing pipe 2 will be rehabilitated as follows. Before applying the first rehabilitation material 3 and the second rehabilitation material 4, a peeling coating material 5 made of a coating material is applied to the inner surface of the existing pipe 2. That is, the coating material is applied to the inner surface of the existing pipe 1. The application method may be spraying with a sprayer or hand application with a roller. The application area is preferably the entire circumference of the inner surface of the existing pipe 2, but it may also be applied in a spiral pattern or grid pattern along the inner surface of the existing pipe 2, thereby forming uncoated areas on the inner surface of the existing pipe 2 where the coating material has not been applied.

[0025] Next, the first rehabilitation material 3 is installed. Here, the spiral-shaped first rehabilitation material 3 is manufactured by spirally winding the strip-shaped member 10 along the inner surface of the existing pipe 2. Next, a second rehabilitation material 4 made of mortar is injected and filled into the gap between the inner surface of the existing pipe 2 and the tubular first rehabilitation material 3. A peeling coating material 5 is interposed between the inner surface of the existing pipe 2 and the second rehabilitation material 4. Eventually, the second rehabilitation material 4 hardens, and the existing pipe rehabilitation structure 1 is constructed.

[0026] In the existing pipe rehabilitation structure 1, the rigidity of the strip-shaped member 10 constituting the first rehabilitation material 3 is increased by including the reinforcing material 20, so that the first rehabilitation material 3 can exhibit the strength of a self-supporting pipe. Therefore, even if a peeling coating material 5 is interposed between the existing pipe 2 and the second rehabilitation material 4, or even if the strength of the existing pipe 2 is not expected to be sufficient, the required strength of the existing pipe rehabilitation structure 1 can be secured.

[0027] When the service life of the existing pipe rehabilitation structure 1 expires and rehabilitation becomes necessary again, the first rehabilitation material 3 and the second rehabilitation material 4 are crushed and removed. At this time, the second rehabilitation material 4 and the existing pipe 2 can be reliably and easily separated due to the easy peelability of the peeling coating material 5 between them. Therefore, it is possible to prevent the existing pipe 2 from collapsing along with the first rehabilitation material 3 and the second rehabilitation material 4. When the first rehabilitation material 3 and the second rehabilitation material 4 are crushed and removed, the interface between the existing pipe 2 and the peeling coating material 5 may be peeled off, and the interface between the second rehabilitation material 4 and the peeling coating material 5 may also be peeled off.

[0028] Even if there are areas that remain uncoated, when the peeling coating material 5 is interposed between the inner surface of the existing pipe 2 and the peeling coating material 5, or between the second rehabilitation material 4 and the peeling coating material 5, the inner surface of the existing pipe 2 and the second rehabilitation material 4 in the uncoated areas can be easily separated as a result. This allows the removal of the first rehabilitation material 3 and the second rehabilitation material 4 to be carried out quickly, efficiently, and safely.

[0029] After removing the first rehabilitation material 3 and the second rehabilitation material 4, new rehabilitation material is installed again on the inner surface of the existing pipe 2. Performing the above removal process prevents the pipe cross-sectional area within the new rehabilitation material from becoming smaller, thus preventing a decrease in flow performance.

[0030] Next, other embodiments of the present invention will be described. In the following embodiments, components that overlap with those described above are denoted by the same reference numerals in the drawings and their descriptions are omitted. <Second Embodiment (Figure 3)> As shown in Figure 3, in the existing pipe rehabilitation structure 1B according to the second embodiment of the present invention, a peeling coating material 6 made of a sheet is provided between the inner surface of the existing pipe 2 and the second rehabilitation material 4. The peeling coating material 6 made of a sheet is fixed to the existing pipe 2 via fixing means 7 such as concrete screws and anchors, but does not adhere to the inner surface of the existing pipe 2 with adhesive force. In other words, the peeling coating material 6 has high peelability from the inner surface of the existing pipe 2.

[0031] The second rehabilitation material 4, which is made of mortar, is attached to a release coating material 6, which is made of a sheet. Preferably, the adhesion strength between the second rehabilitation material 4 and the release coating material 6 is lower than the tensile strength of the second rehabilitation material 4 itself, and the release coating material 6 is easily peeled off from the second rehabilitation material 4.

[0032] As the release coating material 6, for example, polyethylene (PE), PVC sheets, and other resin-based sheets are used, and preferably, a general-purpose resin sheet with low cost is used. The release coating material 6 may also be a sheet having a mesh structure such as a mesh.

[0033] The sheet thickness is preferably around 0.1 mm to 2 mm, but is not limited to this. The sheet size is preferably such that it can be installed by hand, for example, a rectangle with sides of about 1 to 2 m is preferred, but is not limited to this, and a long sheet with a width of 1 to several m is also acceptable.

[0034] When performing rehabilitation work on the aging existing pipe 2, before installing the first rehabilitation material 3 and the second rehabilitation material 4, a peeling coating material 6 made of a sheet is stretched across the inner surface of the existing pipe 2, and the peeling coating material 6 is fixed to the existing pipe 2 by fixing means 7. Preferably, the peeling coating material 6 is provided over the entire inner surface of the existing pipe 2, but there may be areas where the peeling coating material 6 is not provided. Subsequently, the first rehabilitation material 3 and the second rehabilitation material 4 are installed in the same manner as in the first embodiment. In this way, the existing pipe rehabilitation structure 1B is constructed. No special techniques or construction methods are required for the rehabilitation work.

[0035] When the service life of the existing pipe rehabilitation structure 1B expires and further rehabilitation becomes necessary, the first rehabilitation material 3 and the second rehabilitation material 4 are crushed and removed. At this time, the easy peelability of the peeling coating material 6 allows for easy separation of the second rehabilitation material 4 from the existing pipe 2. In particular, since the peeling coating material 6, which is made of a sheet, and the inner surface of the existing pipe 2 are not adhered to each other, the peeling coating material 6 and the existing pipe 2 can be easily separated, and consequently, the second rehabilitation material 4 and the first rehabilitation material 3 from the existing pipe 2 can be easily separated. Therefore, it is possible to reliably prevent the existing pipe 2 from collapsing together with the first rehabilitation material 3 and the second rehabilitation material 4.

[0036] Furthermore, the peeling coating material 6 may be separated from the existing pipe 1 and removed by removing the fixing means 7. If the peeling coating 6 is a sheet with a mesh structure, the second rehabilitation material 4 can directly adhere to the inner surface of the existing pipe 2 through the mesh holes. However, when the peeling coating 6 is pulled off, the attached portion of the mesh holes can also be easily pulled off along with it. This allows the removal of the first rehabilitation material 3 and the second rehabilitation material 4 to be carried out quickly, efficiently, and safely.

[0037] The present invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit. For example, the first rehabilitation material 3 is not limited to the strip-shaped member 10, but may also be composed of a tube, sheath, segment, plate-shaped material, etc., made of resin or resin-impregnated fiber. The first rehabilitation material 3, which is formed in a tubular shape, is not limited to a spiral pipe made of a strip-shaped member 10, but may also be a resin tube or a resin-impregnated fiber tube arranged along the inner surface of the existing pipe 2 by an inversion method or a forming method, or one or more sheath pipes made of multi-fiber reinforced resin or the like arranged in a line in the direction of the pipe axis, or multiple segments or plate-shaped materials may be combined in the direction of the pipe circumference and the direction of the pipe axis to form a tubular shape. The material of the second rehabilitation material 4 is not limited to mortar; it may also be a resin-based material, a foamed material, or the like. [Industrial applicability]

[0038] This invention can be applied, for example, to rehabilitation techniques for aging sewer pipes. [Explanation of Symbols]

[0039] 1. Existing pipe rehabilitation structure 2 Existing pipes 3 First rehabilitation material 4 Second rehabilitation material 5. A release coating material consisting of a coating material. A release coating consisting of 6 sheets. 7 Fixing means 10. Strip-shaped member (profile) 11 Band body 12 Flat strip section 13 Female mating part 14 Male mating part 15 Ribs 20 Reinforcement material 21 Torso 22 Arm

Claims

1. In a method for rehabilitating an existing pipe, a first rehabilitation material mainly composed of synthetic resin is provided in a tubular shape along the inner surface of the existing pipe, and a second filling rehabilitation material is provided between the inner surface of the existing pipe and the first rehabilitation material, A method for rehabilitating an existing pipe, characterized in that, before providing the first and second rehabilitation materials, a peeling coating material consisting of a continuous coating material or sheet is provided over the entire circumference of the inner surface of the existing pipe.

2. The method for rehabilitating an existing pipe according to claim 1, wherein the peeling coating material is easily peelable from either the existing pipe or the second rehabilitation material.

3. In an existing pipe rehabilitation structure in which a tubular first rehabilitation material mainly made of synthetic resin is provided along the inner surface of the existing pipe, and a second rehabilitation material is filled between the inner surface of the existing pipe and the first rehabilitation material, A pipe rehabilitation structure characterized in that a peeling covering material, consisting of a coating material or a sheet, is provided between the inner surface of the existing pipe and the second rehabilitation material, and the peeling covering material is continuous around the entire circumference of the existing pipe.

4. The existing pipe rehabilitation structure according to claim 3, wherein the adhesion strength between one of the existing pipe and the second rehabilitation material and the peeling coating material is lower than the tensile strength of one of the existing pipe and the second rehabilitation material itself.

5. The existing pipe rehabilitation structure according to claim 3 or 4, wherein the first rehabilitation material includes a metal reinforcing material.

6. The existing pipe rehabilitation structure according to claim 3 or 4, wherein the peeling coating material has a spiral pattern or grid pattern along the inner surface of the existing pipe.

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