Rehabilitation method for existing sewer pipes

Abstract

The present invention provides an existing pipe rehabilitation method for repairing and rehabilitating existing pipes consisting of manholes and sewer pipes having irregular shapes, including circular and / or rectangular, horseshoe, and triangular shapes, and which also exhibits excellent chemical resistance and abrasion resistance. [Solution] An existing pipe rehabilitation method for repairing and rehabilitating existing pipes consisting of manholes and sewer pipes having irregular shapes consisting of a circular shape and / or a rectangular shape, a horseshoe shape and a triangle, the method comprising the steps of: attaching and fixing a grid-like reinforcing material made of inorganic fibers to the inner surface of the existing pipe; fixing a sheet-like and / or panel-like structure made of synthetic resin to the back of the reinforcing material with fasteners; flowing an injection material into the space formed between the reinforcing material and the structure and curing and solidifying it; and welding the synthetic resin to the joints formed in the structure after the injection material has cured and solidified.

Description

Technical Field

[0001] The present invention relates to a method for rehabilitating existing pipe channels composed of manholes and sewer pipes, and particularly to a method for rehabilitating existing pipe channels that is excellent in chemical resistance and abrasion resistance.

Background Art

[0002] Regarding the method for rehabilitating existing pipe channels composed of manholes and sewer pipes, it is classified according to the conventional structure and method, and further subdivided according to the method of forming the in-house pipes. Among them, particularly the pipe manufacturing method is known. In this pipe manufacturing method, after installing a spacer on the upper part of the inner surface of the existing pipe, a long strip-shaped pipe component is spirally wound inside the existing pipe, and adjacent wound side edges are joined to assemble a tubular body. It is known that by performing this assembly process with a pipe manufacturing device, it is possible to reduce labor and increase the daily progress in the process.

[0003] In the above process, a nozzle and a hose for injecting the backfill material are passed between the spacer installed on the upper part of the inner surface of the existing pipe and the same pipe, and the backfill material is injected from the nozzle to fill the backfill material between the existing pipe and the tubular body. At this time, the spacer secures a space for inserting the nozzle and the hose, and a space for facilitating the spread of the backfill material, and prevents the tubular body from floating due to the buoyancy of the backfill material. After that, the existing pipe and the tubular body are integrated by the curing of the backfill material, and the existing pipe is rehabilitated.

[0004] However, when the above spacer is installed, the inner space of the rehabilitated existing pipe is greatly biased, and the effective cross-section, which is the cross-section of the inner space, becomes small. Therefore, in the rehabilitation method for pipe channels, it is required to increase the effective cross-section of the rehabilitated existing pipe.

[0005] Furthermore, in the rehabilitation method for pipe channels, it is also required to increase the strength of the rehabilitated pipe channels. Conventionally, reinforcing bars have been arranged and reinforced between the existing pipe channels and the pipe components. However, because reinforcing steel is prone to rusting, Patent Documents 1 and 2 disclose methods for reinforcing existing pipes and concrete structure walls using reinforced fiber lattice reinforcement, which is made by laminating carbon fibers or glass fibers in a lattice pattern, as an alternative to reinforcing steel.

[0006] Furthermore, Patent Document 3 discloses a corrosion-resistant sheet made of synthetic resin, a corrosion-resistant concrete structure, and a construction method applicable to corrosion protection of concrete structures such as manholes and pipelines in sewers. It discloses that the corrosion-resistant sheet is applied to the concrete surface by impregnating a fabric with a room-temperature curing adhesive and then adhering it to it.

[0007] However, each document highlighted various challenges, such as the increased number of work steps due to the large-scale installation of equipment into pipes and manholes, seismic resistance during natural disasters, and increased wear and tear due to aging, necessitating countermeasures. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 5774467 [Patent Document 2] Japanese Patent Publication No. 2010-189834 [Patent Document 3] Japanese Patent Publication No. 2001-32309 [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention was made to solve the problems of the prior art described above, and provides a rehabilitation method for existing pipes consisting of manholes and sewer pipes. [Means for solving the problem]

[0010] The invention according to claim 1 is, A method for repairing and rehabilitating existing sewer pipes consisting of manholes and sewer pipes having a circular and / or irregular shape, wherein the method is: The process involves fixing a grid-like reinforcing material made of inorganic fibers to the inner surface of the existing conduit to which the aforementioned paint has been applied, A step of fixing a sheet-like and / or panel-like structure made of synthetic resin to the back of the reinforcing material with fasteners, A step of allowing an injection material to flow into the space formed between the reinforcing material and the structure and curing and solidifying it, After the injection material has cured and solidified, the process involves welding the synthetic resin to the joints formed in the structure. This invention relates to a method for rehabilitating existing pipes, characterized by comprising the following:

[0011] The invention according to claim 2 relates to the method for rehabilitating existing pipes according to claim 1, characterized in that the inorganic fibers consist of carbon fibers.

[0012] The invention according to claim 3 relates to the method for rehabilitating existing pipes according to claim 1 or 2, characterized in that the synthetic resin is made of a polyethylene resin.

[0013] The invention according to claim 4 relates to the existing pipe rehabilitation method according to claim 3, characterized in that staggered projections are provided at regular intervals on the back surface of the structure.

[0014] The invention according to claim 5 relates to the method for rehabilitating an existing pipe according to claim 3, characterized in that the synthetic resin is heat-fused to the joint portion.

[0015] The invention according to claim 6 relates to the method for rehabilitating an existing pipe according to claim 1, characterized in that the injection material consists of mortar that does not produce excess water after mixing. [Effects of the Invention]

[0016] A method for rehabilitating an existing pipeline consisting of a manhole and a sewer pipe, having a circular shape and / or a non-circular shape according to the invention of claim 1, the method comprising: A step of affixing and fixing a lattice-shaped reinforcing material made of inorganic fibers to the inner surface of the existing pipeline; A step of fixing a structure having a sheet shape and / or a panel shape made of synthetic resin to the back surface of the reinforcing material with a fixture; A step of flowing an injection material into the space formed between the reinforcing material and the structure and curing and solidifying it; A step of welding the synthetic resin to the joint portion formed on the structure after the injection material has cured and solidified; According to the method for rehabilitating an existing pipeline, which is characterized by comprising the above steps, even in a dangerous situation where hydrogen sulfide gas is generated under sulfuric acid-based acidic drainage such as sewage, it has excellent chemical resistance and abrasion resistance, so there is little deterioration even after the rehabilitation work. Furthermore, when a natural disaster such as an earthquake occurs and a situation that affects the pipeline occurs, the structure provided in the rehabilitated pipeline extends in a bellows shape in terms of its structure, reducing the damage to the pipeline and also having excellent earthquake resistance. In addition, since the number of man-hours at the site can be significantly reduced, the construction period can be shortened, and the rehabilitation work can be carried out easily and effectively.

[0017] According to the method for rehabilitating an existing pipeline according to claim 1, wherein the inorganic fiber according to the invention of claim 2 is made of carbon fiber, it has excellent chemical resistance without rusting like a steel frame due to acidic drainage such as sewage, and also has high mechanical strength such as tensile strength.

[0018] According to the method for rehabilitating an existing pipeline according to claim 1 or 2, wherein the synthetic resin according to the invention of claim 3 is made of a polyethylene-based resin, it has high airtightness and anticorrosion performance, is also difficult to break, so it has excellent abrasion resistance, and furthermore has easy processability. The polyethylene-based resin has a large extensibility and has the effect of following the force and not being damaged even when a large force is applied to the existing pipeline such as an earthquake.

[0019] According to the existing pipe rehabilitation method described in claim 3, characterized in that staggered projections are provided at regular intervals on the back surface of the structure according to claim 4, after the injection material has cured and solidified, the staggered shape of the projections on the back surface of the structure provides excellent anchoring effect, preventing air from entering the space formed between the reinforcing material and the structure, and further preventing shifting or peeling after construction due to deterioration over time as the structure becomes heavier due to its own weight, thus providing the effect of stable maintenance.

[0020] According to the existing pipe rehabilitation method described in claim 3, which is characterized by heat-fusing the synthetic resin to the joint portion of the invention according to claim 5, the joint portions, which are gaps, are firmly adhered to each other by the synthetic resin, so that the rehabilitation surface becomes seamless without gaps and can be formed into an integrated synthetic resin lining (tubular body).

[0021] The invention according to claim 6 is characterized in that the injection material is made of mortar that does not produce excess water after mixing. According to the existing pipe rehabilitation method described in claim 1, the water used when mixing the mortar can suppress the separation of sand, cement, aggregate, etc., after placement, thereby ensuring high strength and reducing the likelihood of cracking. [Brief explanation of the drawing]

[0022] [Figure 1A] This is a schematic diagram showing the first step of the existing pipe rehabilitation method according to the present invention. [Figure 1B] This is a schematic diagram showing the second step of the existing pipe rehabilitation method according to the present invention. [Figure 1C] This is a schematic diagram showing the third step of the existing pipe rehabilitation method according to the present invention. [Figure 1D] This is a schematic diagram showing the fourth step of the existing pipe rehabilitation method according to the present invention. [Figure 1E] This is a schematic diagram showing the fifth step of the existing pipe rehabilitation method according to the present invention. [Figure 2A] This is a schematic diagram of the construction of the existing pipe rehabilitation method according to the present invention, and is a cross-sectional view of a circular pipe. [Figure 2B] This is a schematic diagram of the construction of the existing pipe rehabilitation method according to the present invention, and is a cross-sectional view of a rectangular pipe. [Figure 3] (a) A schematic diagram showing a reinforcing structure for the existing pipe rehabilitation method according to the present invention, a schematic diagram showing a front view. (b) A schematic diagram showing a reinforcing structure for the existing pipe rehabilitation method according to the present invention, a schematic diagram showing the intersection of the reinforcing bars of the reinforcing structure. [Figure 4] This is a schematic diagram showing the structure of the existing pipe rehabilitation method according to the present invention, where (1) is a front view and (2) is a cross-sectional view. [Figure 5] This is a schematic diagram showing the welding process to the joints of the existing pipe rehabilitation method according to the present invention. [Modes for carrying out the invention]

[0023] The following describes in detail, with reference to the drawings, a preferred embodiment of the existing pipe rehabilitation method according to the present invention.

[0024] As described above in the background art, the method for rehabilitating existing pipes according to the present invention is suitably used, for example, when the pipe itself is damaged or cracks occur on the wall surface, or in acidic corrosive environments such as sewers and drainage channels. The shape of the existing pipe may be circular and / or irregular. Irregular shapes include, for example, rectangles, horseshoes, and triangular portal shapes. These shapes may also be combinations of multiple shapes.

[0025] In particular, the walls of pipes such as sewers are exposed to a hydrogen sulfide atmosphere generated from sewage, and when hydrogen sulfide adheres to these walls, it reacts with water to form sulfuric acid, which corrodes the walls.

[0026] The rehabilitation method of the present invention is applied to existing pipelines 1 that are subjected to such acidic corrosive environments, particularly when corrosion, cracks, and damage to the pipeline itself occur due to sulfuric acid or the like, making it difficult to maintain them structurally and functionally. In this embodiment, the term "acidic corrosion environment" refers to an acidic atmosphere with a pH of 1 to 3.

[0027] In the rehabilitation method described above, if necessary, a primer or other coating with high adhesive properties may be applied to the wall surface of the existing pipe before fixing the grid-like reinforcing material described later (see Figure 1A). This step is not always necessary. The application method involves evenly coating the wall surface using a brush or sprayer, but it is advisable to first ascertain the condition of the wall surface inside the pipe using a television camera or visual inspection before starting the application work.

[0028] In the situations described above, if there is damage to the wall, water seepage, or further intrusion of tree roots, it is advisable to take appropriate measures. Furthermore, to enhance the adhesive effect after coating, it is desirable to perform surface preparation such as scraping or cleaning, or to perform high-pressure water washing on the wall surface.

[0029] Next, the reinforcing material 2 shown in Figures 3(a) and 3(b) is attached to the wall surface and fixed in place after the coating process (see Figure 1B). Reinforcement 2 is composed of a grid of high-tensile carbon fibers integrally laminated together, as shown in Figures 3(a) and 3(b).

[0030] Reinforcement 2 has a very low specific gravity, and because the intersections of the grid are flush, it is thinner than reinforcing bars. Furthermore, because reinforcement 2 has high-strength and high-elasticity continuous reinforcing fibers arranged in both vertical and horizontal directions, it has the same reinforcing effect as reinforcing bars. Furthermore, since structure 2 does not rust and has excellent corrosion resistance, deterioration due to corrosion can be avoided.

[0031] Here, we will explain reinforcement 2 in detail with reference to Figure 3(b). The reinforcing element 2 typically comprises multiple reinforcing bars arranged in a grid pattern at right angles to each other, namely, longitudinal reinforcing bars 21 and transverse reinforcing bars 22. In this embodiment, each reinforcing bar 21, 22 is formed by laminating multiple carbon fiber layers 20a, in which carbon fibers are arranged in one direction, and then curing them.

[0032] Reinforcement 2 has a reinforcement width (w) of 1 to 50 mm, usually 2 to 20 mm, a thickness (t) of 1 to 100 mm, usually 2 to 20 mm, and a grid spacing (W) of 1 to 50 cm. Specifically, it is preferable that the reinforcement width (w) × thickness (t) is 6.6 square mm to 17.5 square mm, and the grid spacing (W) is 5 to 10 cm. Furthermore, although each reinforcing bar 21 and 22 is arranged perpendicular to each other, it is also possible to configure them to intersect at predetermined angles other than 90°, as desired, to form a grid.

[0033] Examples of reinforcing fibers used include inorganic fibers such as carbon fibers, glass fibers, and ceramic fibers; organic fibers such as fully aromatic polyamide fibers, fully aromatic polyester fibers, and aramid fibers; and metallic fibers such as titanium and steel. However, inorganic fibers are preferred due to their superior chemical resistance and mechanical strength, such as tensile strength, and carbon fibers are the most preferred.

[0034] Reinforcement 2 is fixed to the inner surface of the existing pipe using a physical fixing method, as shown in 5 of Figure 2B. In particular, it is preferable to fix it using fasteners that are spaced at a predetermined distance from the repaired or rehabilitated surface of the existing pipe. It is preferable that reinforcement 2 be embedded and fixed in the injection material, as this improves the reinforcement effect. Two or more reinforcement 2 may be stacked and fixed. It is important that when installing reinforcement 2, there are no areas where reinforcement 2 is absent. It is important to avoid leaving any areas where reinforcement 2 is absent, for example, by installing and fixing two reinforcement 2 so that the lattice structure overlaps at the edges of reinforcement 2.

[0035] Thus, when carbon fiber is used as the reinforcing fiber, the reinforcing material 2 has a strength of 1400 N / mm². 2 The above tensile strength, and 100,000 N / mm² 2 It has the above tensile modulus of elasticity. For example, the reinforcing material 2 can be shrunk into a roll and easily transported into an existing pipe. Furthermore, it is preferable that the carbon fiber surface of reinforcing material 2 be surface-treated, as this can prevent scratches.

[0036] Furthermore, a fastener (concrete anchor) 5 is used to secure the reinforcing material 2 (see Figure 2B). The fastener 5 is preferably made of plastic. Using a plastic fastener reduces the risk of corrosion due to acid.

[0037] Furthermore, the method of fixing the reinforcing material 2 with the fastener 5 is not limited, but the fastener 5 is driven into the inner surface of the pipe at the corner of the grid of the reinforcing material 2, that is, at the intersection of the grid bars 21 and 22 (see Figure 3(b)), and if necessary, a fastener retaining plate (not shown) or the like is used to press and fix the reinforcing material 2 toward the inner surface of the pipe. The fasteners 5 are driven into the ground every 2 or 3 squares of the reinforcing material 2, but the driving positions are not limited to these.

[0038] Next, a lining structure 3 (see Figure 4), which is a sheet or panel made of synthetic resin, is wrapped around or arranged on the upper surface of the fixed reinforcing structure 2 and secured using fasteners (see Figure 1C). On the back surface of the above-mentioned structure 3, protrusions are arranged at predetermined intervals to enhance integration with the solidified and cured injection material, which will be described later.

[0039] Structure 3 has a sheet-like and / or panel-like form. The sheet-like structure is effective when repairing and rehabilitating existing pipes that have curved surfaces because it conforms to the curved surface. The panel-like structure is effective when repairing and rehabilitating existing pipes that have flat surfaces, such as rectangular or triangular portal-type structures, because it can be assembled facing the flat surface. Structure 3 is fixed at a position where the desired thickness can be obtained, spaced apart from the repaired and rehabilitated surfaces of the existing pipe, as well as from the reinforcing material 2.

[0040] Structure 3 is provided with projections having a roughly V-shaped cross-section (see Figure 4(2)). As a result, these projections improve the entanglement with the grout material through an anchoring effect, allowing for greater integration between structure 3 and the grout material. Furthermore, the roughly V-shaped projections are arranged in a roughly staggered pattern on the sheet-like or panel-like structure (see Figure 4(1)). Therefore, when the grout material is injected, no air is trapped near structure 3, ensuring that the structure and the grout material are firmly fixed together, enabling robust pipe rehabilitation.

[0041] Furthermore, it is desirable to install the above-mentioned protrusions at intervals of 40 to 100 mm, and especially at 44 mm intervals.

[0042] Here, synthetic resins such as polyester, polyamide (nylon), polyethylene, and polypropylene can be used as the above-mentioned structure. From the viewpoint of chemical resistance and abrasion resistance, polyethylene resin is preferable. Polyethylene resin has approximately 30 times the abrasion resistance of polyvinyl chloride. In addition, polyethylene resin has excellent extensibility of approximately 600%. As a result, even if strain occurs in the existing conduit due to earthquakes or other events, it can expand and follow the bending displacement.

[0043] Furthermore, since the amount of fluid flowing through the pipe decreases, it is preferable to use a material that is strong even if it is thin for the structure. The thickness of this structure is preferably in the range of 2 to 10 mm, and especially 3 to 5 mm. If the thickness is less than 2 mm, the structure will be weak and will have difficulty standing on its own. Conversely, if the thickness exceeds 10 mm, the structure will be too strong, making construction difficult in areas with small diameters, and the structure will be heavy, which may cause displacement or spalling after construction.

[0044] Furthermore, when fixing the above-mentioned structure, the structure is first installed on the formwork and then secured with fasteners.

[0045] After fixing structure 3 inside the reinforcing material 2 within the conduit, the injection material is poured into the gap S between reinforcing material 2 and structure 3 via hose 8, filling the gap and allowing it to solidify (see Figure 1D). Mortar is preferred as the injection material, and inorganic cement mortar, polymer cement mortar, asphalt mortar, resin mortar, etc. can also be used, but it is particularly preferable to use one that does not shrink and does not have bleeding properties, meaning that no excess water is generated after mixing with the mortar.

[0046] Finally, the joints 10, which are gaps at the ends of the structure, are heat-sealed with a sealant made of the same material as the structure, such as a fast-curing polyethylene resin (see Figures 1E and 5). Additionally, scaffolding hardware and other necessary items will be restored inside the pipes as needed.

[0047] As described above, according to the construction method of the present invention, rehabilitation work on existing sewer pipes consisting of concrete manholes and sewer pipes can be completed in a short construction period. In particular, because it uses polyethylene structures with a thickness of 3-5 mm, it is self-supporting and can be constructed in a short time. Furthermore, it allows for appropriate rehabilitation and repair depending on the degree of deterioration of the concrete on the pipe wall. Furthermore, this construction method is suitable for circular conduits with an inner diameter of Φ800mm, and for rectangular conduits, it is suitable if both the length and width are 800mm or more, and it allows workers to perform the work safely. [Examples]

[0048] The effects of the present invention will be made clearer by showing the following examples of the existing pipe rehabilitation method according to the present invention. However, the present invention is not limited in any way to these examples.

[0049] The following describes one embodiment of the method for rehabilitating existing pipes according to the present invention. This embodiment involves the rehabilitation of an existing box culvert. This box culvert houses underground power transmission lines and has a manhole on top that serves as an access point for inspections and other purposes. Multiple power transmission line conduits for bringing in power transmission lines are formed in the wall surface of the box culvert, and in this embodiment, the wall surface below the opening of the power transmission line conduits was reinforced. The deterioration was such that cracks had formed in the concrete and water was leaking from the cracks.

[0050] Herein, the reinforcing materials, structures, and injection materials used in this embodiment will be described below. Reinforcement 1 is a grid reinforcement made of carbon fiber. Considering the ease of construction at the site, reinforcement 1 was made with a reinforcement width (w) x thickness (t) of 6.6 square mm and a grid spacing (W) of 5 cm. Furthermore, regarding the carbon fibers used in the reinforcement according to the present invention, strength tests were conducted on their tensile strength and tensile modulus using a test method in accordance with the Japan Society of Civil Engineers standard JSCE-E531-1999 "Tensile Test Method for Continuous Fiber Reinforcements". The tensile strength was found to be 1400 (N / mm²). 2 ) or more, tensile modulus is 100,000 (N / mm²). 2 The above results were obtained for each case, confirming that they possess high strength.

[0051] Furthermore, the structure in this embodiment is made of polyethylene panels, and multiple panels were fixed to the wall surface according to the construction conditions to carry out the rehabilitation. Furthermore, the structure in this embodiment was tested for strength (tensile strength, tear strength, elongation at fracture), specific gravity, and brittleness temperature, etc., using test methods compliant with Japanese Industrial Standards JIS K6760 and 6301, respectively, and it was confirmed that the measured values ​​converged within the range of the standards.

[0052] Furthermore, regarding the chemical resistance and abrasion resistance of this structure, tests were conducted using test methods compliant with the Japan Sewage Works Agency's "Guidelines and Manual for Corrosion Inhibition and Corrosion Prevention Technologies for Concrete Sewage Structures" and the Japanese Industrial Standard JIS K7204, respectively, and it was confirmed that the structure possesses the above-mentioned characteristics.

[0053] Furthermore, the injection material M used in this embodiment is a mortar having the aforementioned characteristics of being free from shrinkage and bleeding, and experiments were conducted on its compressive strength after curing for a predetermined number of days. The results are shown in Table 1.

[0054] [Table 1]

[0055] First, we examined the structure of the pipe wall to be rehabilitated and estimated its bending, shearing, and thrust-out shearing strength. While detailed calculations are omitted as the purpose was to determine the strength of the wall to be rehabilitated and confirm its strength in its existing state, the results showed that it possessed sufficient bending, shearing, and thrust-out shearing strength.

[0056] Next, we examined the current condition of the existing wall surface and considered its potential for rehabilitation. In this example, although the load-bearing capacity was confirmed to be sufficient in all cases during the load-bearing capacity check, the current condition of the wall surface shows cracks in the concrete and water leakage from the cracks. Therefore, after examining the factors causing the discrepancy between the structural calculation results obtained above and the current condition, it was determined that the current wall surface deterioration is due to these factors, and a construction plan was created based on the calculation results and the condition of the wall surface.

[0057] Next, I will explain the construction process. First, as a preliminary step, wire protection and drainage treatment were carried out. Since the wall surface 4 to be reinforced has a power transmission line conduit opening and power transmission lines are drawn into it, it is necessary to protect the power transmission lines. In addition, water was leaking from cracks in wall surface 4 and accumulating inside the box culvert, so the accumulated water was removed beforehand.

[0058] We performed water-stopping and drainage treatment on the leaking sections of the wall that needed rehabilitation. Since it was not possible to install reinforcement while the wall was leaking, we injected water-stopping materials such as urethane-based water-stopping material into the leaking sections. In areas where the injection of this waterproofing material was insufficient to stop water leakage, measures such as installing water conduits were taken to stop leaks from the wall surface being constructed.

[0059] Furthermore, the wall surface that needed rehabilitation was chipped away and its cross-section repaired. When the wall surface is severely deteriorated, it may be difficult to integrate it with the reinforcement and install it in its original state. In such cases, the wall surface is chipped away and its cross-section repaired. In this example, due to the severe deterioration, the wall surface was chipped away to a depth of 5 cm, and polymer cement mortar was used to fill in cracks and areas with cross-sectional defects to repair it.

[0060] After repairing the aforementioned wall surface, the reinforcement 2 was set in the designated location according to the construction plan and secured using fasteners. At this point, it became necessary to connect and extend the reinforcing structures, and since the reinforcing structures were arranged in a grid pattern, they were installed and fixed in place, overlapping every two sections.

[0061] Furthermore, after setting and fixing the reinforcing members 2 in the designated locations, the formwork was installed in the direction of fluid flow in the conduit, and the panel-shaped structures 3 were attached to the dedicated formwork. Next, an injection material (PL mortar, manufactured by Chichibu Concrete Industry Co., Ltd.) was poured between the repaired and rehabilitated surfaces of the pipe and structure 3, and then cured and solidified. Reinforcement 2 was embedded in the mortar.

[0062] After the injected material had cured and solidified, the formwork attached to the structure was removed, and, if necessary, the joints of reinforcement 2 were sealed by heat fusion using polyethylene resin wire.

[0063] By implementing this construction method, the pipe wall P, the reinforcing material 2, and the structure 3 are integrated, allowing for reinforcement of cracks in the wall surface and suppression of wall displacement due to water pressure. Furthermore, compared to conventional rehabilitation methods, this method eliminates the need for rebar placement and concrete pouring, thus improving construction efficiency.

[0064] In this embodiment, the rehabilitation method was applied to rehabilitate a box culvert. However, the rehabilitation method according to the present invention is applicable to various locations. Furthermore, when applying the reinforcing materials, structures, and injection materials used in the method according to the present invention, the shape of the wall surface to be rehabilitated is not limited to a flat surface, but can also be curved.

[0065] In addition to the embodiments described above, the present invention can be modified in various ways without altering the essence of the invention. In the above embodiment, a reinforcement made of carbon fiber was exemplified, but the present invention is not limited thereto, and a reinforcement made of reinforcing fibers mixed with fibers that have excellent chemical resistance and mechanical strength can also be applied.

[0066] Furthermore, although the above embodiment shows an example in which the reinforcing material 2 is fixed to the wall surface of the existing conduit P using a fastener 5, the present invention is not limited to this, and the reinforcing material 2 may also be fixed to the wall surface of the existing conduit P using simple fastening members such as small pegs or nails, and any method is applicable as long as it reduces the stress generated in the existing conduit P when attached to the wall surface of the existing conduit P.

[0067] Furthermore, while the above embodiment illustrates an example in which an injection material M is flowed and filled into the gap S between the pipe wall of the conduit and the structure 3, the present invention is not limited to this. For example, holes may be drilled from the inside of the tubular body formed by the structure using a drill or the like, and the injection material M may be filled through the holes using a nozzle or hose for injecting backfill material. The location and number of holes to be drilled can be appropriately set considering the size of the tubular body and the gap S.

[0068] Furthermore, in the supply of the injection material, a step of mixing short fibers into the injection material M may be incorporated. The short fibers mixed into the injection material M will entangle with the staggered protrusions of the structure, and after the injection material M has cured and solidified, the bonding force between the injection material M, the reinforcement 2, and the structure 3 will increase, making it possible to further increase the strength of the rehabilitated existing pipe P.

[0069] In the embodiments described above, examples were given of applying the method of the present invention to the rehabilitation of existing circular and rectangular conduits P. However, the method of the present invention can also be applied to the rehabilitation of existing conduits with irregular shapes, such as horseshoe-shaped or triangular conduits. [Industrial applicability]

[0070] The present invention is particularly suitable for use in narrow sections of manholes and waterways, as well as in environments where corrosive gases such as hydrogen sulfide are generated, in addition to conduits. This includes the rehabilitation method, reinforcing materials, structures, and injection materials used in the present invention. [Explanation of Symbols]

[0071] 1: Rehabilitated pipes 2: Reinforcements 3: Structure 5: Fixtures 8: Hose 10: Joint area 20a: Carbon fiber layer 21, 22: Grid lines P: Existing conduit S: Gap M: Injection material

Claims

1. A method for repairing and rehabilitating existing sewer pipes consisting of manholes and sewer pipes having a circular and / or irregular shape, wherein the method is: The process involves fixing a lattice-shaped reinforcing material made of inorganic fibers to the inner surface of the existing conduit, A step of fixing a sheet-like and / or panel-like structure made of synthetic resin to the back of the reinforcing material with fasteners, A step of allowing an injection material to flow into the space formed between the reinforcing material and the structure and curing and solidifying it, After the injection material has cured and solidified, the process involves welding the synthetic resin to the joints formed in the structure. A method for rehabilitating existing pipes, characterized by comprising the following.

2. The method for rehabilitating an existing pipe according to claim 1, characterized in that the inorganic fiber consists of carbon fiber.

3. The method for rehabilitating an existing pipe according to claim 1 or 2, characterized in that the synthetic resin is made of a polyethylene resin.

4. The method for rehabilitating an existing pipe according to claim 3, characterized in that staggered projections are provided at regular intervals on the back surface of the aforementioned structure.

5. The method for rehabilitating an existing pipe according to claim 3, characterized in that the synthetic resin is heat-fused to the joint portion.

6. The method for rehabilitating an existing pipe according to claim 1, characterized in that the injection material consists of mortar that does not generate excess water after mixing.

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