JPH0827822A - Manhole repairing method and material - Google Patents

Abstract

PURPOSE:To form a lining layer having sufficient repairing effect and having a smooth inside within a short period of time. CONSTITUTION:A cylindrical section 3 of a manhole repairing material is so constructed that an interior wall surface 19 and a space 37 are provided inside a manhole 15. The space 37 is filled with lining ordinary temperature hardening epoxy resin 43. After the lining ordinary temperature hardening epoxy resin 43 is solidified, a cut head conical section 5 is so mounted to the upper end of a cylindrical section 3 that it is provided with an interior wall surface 19 and a space 49. The space 49 is filled with the lining ordinary temperature hardening epoxy resin 51 to leave it alone until the epoxy resin is solidified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manhole repair method for lining and repairing a manhole and a manhole repair material particularly suitable for use in the repair method.

[0002]

2. Description of the Related Art A manhole is generally made of concrete, and its inner wall surface is corroded for a long time by hydrogen sulfide generated in an underground pipe, especially by a sulfur oxide in rainwater.
In addition, since many manholes are buried in public roads, cracks may occur on the inner wall surface due to vehicle vibration. If corrosion of the inner wall of the manhole progresses or cracks occur on the inner wall, groundwater will enter the underground pipe, and in the case of sewage pipe, the amount of sewage will increase due to the infiltrated groundwater, and the number of man-hours for sewage treatment will increase. There is also a possibility of doing it. If this state is left unattended, the manhole may collapse, so
The inner wall of the manhole must be repaired at an appropriate time.

As a method of repairing the inner wall surface of the manhole,
For example, JP-A-64-29526 and JP-A-64-4
As described in Japanese Patent No. 3623 or Japanese Patent Laid-Open No. 1-198325, a material in which a tubular repair material is fixed to an inner wall surface is generally adopted, but a ceramic-containing liquid resin or a hard liquid urethane resin. There is also used a method in which the inner wall surface is sprayed with to form a lining layer.

[0004]

By the way, when the inner wall surface of the manhole is severely corroded or a large crack is formed, if the lining layer is formed by using the above-mentioned repairing method, the lining layer is formed according to the corrosion and the crack. The lining layer to be formed undulates and the finish of the repaired inner surface is not good.
Moreover, in the method in which the liquid resin is sprayed on the inner wall surface, when the groundwater intrudes from the inner wall surface, the resin does not sufficiently adhere to the inner wall surface at the invading portion, and the lining layer at this portion may be peeled off.

In order to solve such a problem, after cleaning the inner wall surface with high-pressure water or the like, the leaked portion is stopped with quick-setting cement or the like, and then the mortar is used to correct the unevenness of the inner wall surface to form a smooth surface. Although a pretreatment work to be formed is required, it takes several days to complete the pretreatment work, so that the work efficiency is poor and the occurrence of traffic obstacles is also a problem.

Therefore, the present invention has a sufficient repair effect,
Moreover, it is an object of the present invention to provide a manhole repair method capable of forming a lining layer having a smooth inner surface in a short time and a manhole repair material suitable for use in this method.

[0007]

In order to achieve this object, the manhole repair method of the present invention is a manhole repair method for lining and repairing the inside of a manhole, which is made of plastic so as to cover the inner wall surface with a gap. The thin repair material is placed in a manhole, and then a liquid room temperature-curable injection material for lining is filled in the gap between the inner wall surface and the repair material to be cured. When arranging the repair material in the manhole, an annular water stop projection having a diameter smaller than the inner wall surface is formed on the bottom surface of the manhole, and a liquid curable injection material is poured between the annular water stop projection and the inner wall surface. It is preferably cured.

The repair material is preferably a tubular body formed to cover the inner wall surface of the manhole and provided with a vertical cut portion at one location. As the tubular body, a cylindrical tubular body and this tubular body are used. In many cases, two types are used, that is, a truncated cone-shaped tubular body placed on the upper end of a cylindrical tubular body. It is effective to provide a plurality of longitudinally extending ribs for forming a gap on the outer surface of the tubular body in the circumferential direction, and the ribs of the repair material are pressed against the inner wall surface of the manhole so as to be closely attached. Cancel the overlap state. The ribs do not necessarily have to extend continuously in the longitudinal direction, but may extend intermittently.
The outer end of the rib may be corrugated or a recess may be formed at the outer end of the rib so that the cold-setting injection material for lining can easily pass between the rib and the inner wall surface of the manhole.

The bending elastic modulus of the tubular body is 100 kg / mm ^2.
It is preferably 1500 kg / mm ² or less.
Plastics to be used include thermoplastics such as polyethylene, polypropylene, vinyl chloride and polyamide, and thermosetting plastics such as unsaturated polyester, acryl and epoxy, and fiber reinforced unsaturated polyester is particularly preferable. It is effective that the gap between the inner wall surface and the repair material is 2 mm or more and 10 mm or less. Also, the kinematic viscosity of the room temperature hardening injection material for lining is 30 at 25 ° C.
It is preferably 00 cSt or less, and a small amount of a curable water blocking material may be injected and cured prior to filling with the room temperature curable injection material for lining. It is possible to use liquid rubber such as liquid urethane resin and polybutadiene, but it is suitable to use epoxy resin, acrylic resin or unsaturated polyester resin as the room temperature curable injection material for the lining and the curable water blocking material. It is effective to seal the lower end of the repair material to seal between the lower end of the repair material and the bottom of the manhole or the hardened curable injection material.Here, the inside of the lower end of the repair material and the manhole are used. In many cases, the sealing material can be applied to the bottom surface of the base material or the cured curable injection material.

[0010]

[Function] In many cases, a repair material (often made of fiber reinforced plastic) having rigidity that can maintain the standing state is used, and the repair material is directly pressed against the inner wall surface to form the lining layer. Since this is not the case, the repair material is less likely to have undulations corresponding to the unevenness of the inner wall surface. An extremely excellent repair effect is achieved by the repair material and the room temperature hardening injection material for the lining, but in some cases, after the room temperature hardening injection material for the lining is cured, the repair material is removed and the lining layer is formed only by the injection material. May be configured. In this case as well, the inner surface of the room-temperature-curing injection material for lining was in contact with the repair material, and thus formed smooth. The room temperature curable injection material for lining, which is filled in the gap between the inner wall surface and the repair material, enters the corroded portions and cracks of the inner wall surface and has a sufficient water blocking function and a reinforcing function. Therefore, it is sufficient to clean the inner wall surface using high-pressure water, a rotating brush, or the like as necessary for the pretreatment operation.

The bottom surface of the manhole has irregularities due to corrosion and strong deposits. Therefore, when the repair material is placed directly on the bottom surface of the manhole, the repair material is inclined and the lining layer formed is also inclined. The repair material is a tubular body that covers the inner wall surface at least when it is arranged in the manhole, in other words, covers the inner wall surface in an annular shape. Therefore, if an annular water-stop projection is formed on the bottom surface of the manhole, and a liquid curable injection material is poured between it and the inner wall surface to cure it, the upper surface of the cured curable injection material will be the liquid surface of the liquid material. It is a smooth horizontal surface because it is made. Therefore, the annular or annularly deformed repair material can be placed on the upper surface of the curable injection material and placed in the manhole vertically without tilting. The diameter of the annular water-stop projection is usually smaller than the diameter of the repair material in the arranged state.

In most cases, the entrance of the manhole is smaller in diameter than the middle part and the lower part. Therefore, the repair material is deformed so that it can pass through the inlet and is inserted into the manhole. However, since the repair material preferably has a certain degree of rigidity, a structure that is easily deformed should be adopted. A simple cylindrical body is hardly deformed to a small diameter, and a simple plate body is often difficult to be wound into a roll and deformed to a small diameter. If you use a tubular body that is cut vertically in one place as a repair material, you can deform this tubular body so that it will be in an overlapped state and easily reduce the diameter, and you can easily overlap in a manhole. You can also cancel the status. At this time, the seal of the cutting portion may be partially overlapped and fixed, or the both ends of the cutting portion may be sealed by using butting members.
It is quite difficult to release the overlapped state of the tubular body and form a uniform and proper gap between the tubular body and the inner wall surface of the manhole. Therefore, if a plurality of ribs for longitudinally extending gaps are provided in the circumferential direction on the outer surface of the tubular body, and the overlapping state is released so that these ribs are in close contact with the inner wall surface of the manhole, the inside can be easily A uniform gap can be formed with the wall surface. The ribs usually have a height (projection amount) corresponding to the gap to be formed. Further, the upper part of the manhole is often formed in a frustoconical shape whose diameter decreases toward the entrance. When the inner wall surface of the manhole is entirely lined, if the frusto-conical portion and the cylindrical portion are integrally formed, the frusto-conical portion and the cylindrical portion have different deformation modes for smooth overlap. Therefore, it is difficult to reduce the diameter by overlapping. Therefore, the frusto-conical portion and the cylindrical portion are separately configured, the cylindrical portion is first deformed to a small diameter and placed in the manhole, and then the frusto-conical portion is deformed to a small diameter and placed. Is effective. In this case, after arranging the cylindrical portion, the outside of the cylindrical portion is filled with the room temperature curable injection material for lining, and thereafter, the truncated cone-shaped portion is arranged to the outside of the truncated cone-shaped portion. The lining cold-setting injectable material may be filled, or the lining cold-setting injectable material may be filled after the cylindrical portion and the frusto-conical portion are arranged. The tubular body has a flexural modulus of 100 kg /
If it is less than mm ^2, it may be curved inward largely due to its own weight and the liquid pressure of the room temperature-curable injection material for lining, and may be undulated depending on the irregularities of the inner wall surface. Conversely, if the flexural modulus exceeds 1500 kg / mm ² , it will be difficult to deform during insertion.

If the gap between the inner wall surface and the repair material is less than 2 mm, it is difficult to fill the room temperature curable injection material for lining, and air retention may occur or the injection material may not reach the lower end. On the other hand, if it exceeds 10 mm, the room-temperature-curable injection material for lining is unnecessarily used, and the degree of shrinkage due to the curing of the injection material is too large, which may cause the repair material to swell.

If the kinematic viscosity of the room temperature curable injection material for lining exceeds 3000 cSt at 25 ° C., it is difficult to fill the gap between the inner wall surface and the repair material, and air retention occurs.
The injection material may not reach the lower end. If the kinematic viscosity is large even at 3000 cSt or less, it can be said that there is a possibility that air retention will occur due to environmental conditions. Therefore, it is preferable that the kinematic viscosity of the room temperature hardening injection material for lining is small. However,
If the space between the repair material and the inner wall surface is filled with the room temperature curable injection material for lining having a small kinematic viscosity at one time, there is a possibility that it may leak from the lower end of the repair material. First, if a curable water blocking material is injected and cured, a sufficient water blocking structure can be constructed so that the lining room temperature curable injection material for filling will not leak out. Further, in order to prevent the leakage of the room temperature hardening injection material for lining, it is also effective to seal the lower end portion of the repair material. If a seal is applied when injecting the curable waterproof material, it is possible to provide a double excellent sealing structure for the room temperature curable injection material for the lining while completely preventing the curable waterproof material from leaking. .

Epoxy resins, acrylic resins and unsaturated polyester resins are all inexpensive and have excellent adhesiveness.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a manhole repair material according to the present invention.

The manhole repair material 1 is composed of a plastic cylindrical portion 3 and a truncated cone portion 5, and each of the cylindrical portion 3 and the truncated cone portion 5 has a vertical cut. Parts 7, 9 are provided. In order to form the cylindrical portion 3 and the truncated cone-shaped portion 5, a fiber-reinforced unsaturated polyester is molded by a hand lay-up method in a die having a cylindrical outer surface and a die having a truncated cone outer surface, and the die is removed. After performing the cutting, each may be cut at one position in the vertical direction, but the cutting portions 7 and 9 may be formed simultaneously during molding. The outer surface of the mold is formed so as to correspond to the inner wall surface of the manhole to be repaired.

In the figure, reference numerals 11 and 13 are ribs for forming a gap provided on the outer surface of the manhole repair material 1, which are equally spaced in the circumferential direction (the intervals between the cut portions 7 and 9 are large). Are provided in multiple. The ribs 11 extend from the upper end to the lower end of the cylindrical portion 3, and the ribs 13 extend from the upper end to the lower end of the frustoconical portion 5, and the protrusion amount (height) of all the ribs 11 to the outside is about 6 mm. Equal and all ribs 13
The amount of protrusion (height) to the outside is also approximately 6 mm.

FIG. 2 is a sectional view showing a modification of the manhole repair material according to the present invention.

In this modification, the cylindrical portion 3 and the frustoconical portion 5 are used.
The joint structure with is changed. A cylindrical portion 6 is formed at the lower end of the truncated conical portion 5 ′ of the manhole repair material 1 ′, and the cylindrical portion 6 is formed so as to fit outside the upper end portion of the cylindrical portion 3. The rib 11 'for forming a gap ends before the upper end of the cylindrical portion 3, and the rib 13' for forming a gap is not formed on the tubular portion 6.

FIG. 3 is a sectional view showing a state inside the manhole before the manhole repair material 1 is placed.

On the bottom surface 17 of the manhole 15, an annular water stop projection 21 having a diameter smaller than that of the inner wall surface 19 is formed by using glass putty, and a closing plate 27 is provided at the opening end 25 of the sewer pipe 23.
Has been fixed. A liquid room temperature curable acrylic resin 29 (curable injection material) is poured between the inner wall surface 19 and the annular water-stop projection 21 (and the closing plate 27) and cured.
The room temperature curable acrylic resin 29 has a small kinematic viscosity, and therefore it cures after the liquid surface becomes horizontal, so that the upper surface 31 is a smooth horizontal surface.

FIG. 4 is a sectional view showing a state in which the cylindrical portion 3 is arranged in the manhole 15.

The cylindrical portion 3 has a bending elastic modulus of about 800 kg /
The diameter is mm ² and the diameter is reduced so that the overlapped state is achieved in the manner shown by the phantom line in FIG. After that, the rib 11 is pressed against the inner wall surface 19,
The overlapped state is released and the diameter is expanded so that the lower end is placed on the upper surface 31 of the room temperature curable acrylic resin 29. Then, the cut portion 7 which is in a slightly overlapped state (overlap of about 10 mm) is fixed with the tape 35 and hermetically sealed. A plurality of gaps 37 of about 6 mm are formed between the cylindrical portion 3 and the inner wall surface 19 by being partitioned by the rib 11. When the manhole 15 is deep, the cylindrical portion 3 may be formed by stacking a plurality of cylindrical members.

Next, the inside of the lower end of the cylindrical portion 3 is water-stopped (sealed) with a quick-setting cement 39, and then the room temperature curable acrylic resin 41 (25) is provided from above to below the respective gaps 37 between the inner wall surface 19. Inject kinematic viscosity at c of 100 cSt: curable water blocking material). Even when the cylindrical portion 3 is directly placed on the bottom surface 17 of the manhole 15 without providing the annular water-stop projection 21, first, water is stopped between the inside of the lower end portion and the bottom surface 17 with a quick-setting cement or the like. After the room temperature curable acrylic resin 41 is cured to form a sufficient waterproof structure, the room temperature curable epoxy resin 43 for lining (kinematic viscosity at 25 ° C. is 300 cS
t: Room temperature curable injection material for lining) is filled into each of the gaps 37 from above and cured. The kinematic viscosity of the room temperature curable injection material for lining is optimally 100 cSt to 500 cSt at 25 ° C. In this way, with the seal and the (normal temperature) hardening water blocking material, first, if the lower water blocking structure is made sufficient, the movement of the room temperature hardening filling material for lining to be filled next will be performed under any environmental condition. It is possible to lower the viscosity. If the kinematic viscosity of the room temperature curable injection material for lining is low, the injection material penetrates into the corroded parts of the inner wall surface 19 and every corner of the crack and hardens.
You can expect a water stop effect.

Even if groundwater or the like remains in the gap 37, the specific gravity is set to 1 so that the waterproofing material and the injecting material are filled in the lower side.
It is preferable to use the above water-stopping material and injection material.

FIG. 5 is a sectional view showing a state in which the frustoconical portion 5 is arranged in the manhole 15.

Room temperature curable epoxy resin 43 for lining
After curing, the frusto-conical portion 5 having a bending elastic modulus of about 800 kg / mm ² is reduced in diameter so as to be in an overlapped state in the manner shown by the phantom line in FIG. After that, the rib 13 is pressed against the inner wall surface 19, and the overlapped state is released so that the lower end is placed on the upper end of the cylindrical portion 3 to expand the diameter. Then, the cut portion 9 which is in a slightly overlapped state (overlap of about 10 mm) is fixed by the tape 45 and sealed, and the lower end of the truncated cone portion 5 and the upper end of the cylindrical portion 3 are fixed by the tape 47. And seal. A plurality of gaps 49 of about 6 mm are formed between the truncated conical portion 5 and the inner wall surface 19 by being divided by the ribs 13.

Next, the respective gaps 49 with the inner wall surface 19
Room temperature curable epoxy resin for lining 5 from above
1 (kinematic viscosity at 25 ° C., 300 cSt: normal temperature curable injection material for lining) is filled and cured.

Since the curing time of a normal room temperature curable injection material is about 6 hours, if it is necessary to shorten the repairing time, after the cylindrical portion 3 and the truncated conical portion 5 are arranged, It is a good idea to fill it with a room temperature curable injection material. In this case, it is advantageous in terms of placement work to use the repair material 1'shown in FIG. 2 that is easier to assemble.

Then, as shown in the figure, a hole 53 is formed in the open end 25 portion of the sewer pipe 23, and the tapes 35, 45 and 47 are formed.
To complete the repair work. As shown in FIG. 6, the room temperature curable epoxy resins 43 and 51 for the lining are sufficiently hardened by entering the corroded portions and cracks of the inner wall surface 19.
Further, the room temperature curable epoxy resin for lining 43, 51
Since the repair material 1 may be removed so that it can be repeatedly used, since a large number of ribs 11 and 13 are provided as in this embodiment, a room temperature curable epoxy for lining is removed after removal. Since the post-treatment work is required for the resins 43 and 51, the ribs 11 and 13 should not be provided on the repair material 1 when the resin 43 and 51 are removed, or
It is desirable to reduce the number of 1 and 13. To remove it, it is sufficient to apply a release agent to the outer surface of the repair material 1, but if the repair material 1 is made of polypropylene, polyethylene or fluororesin and has a good release property, dare to do so. It is not necessary to apply a release agent.

The cutting portion 7 of the cylindrical portion 3, the cutting portion 9 of the frustoconical portion 5, the upper end of the cylindrical portion 3 and the frustoconical portion 5 are used.
It is preferable to configure a fitting structure such as a fitting type at the lower end of the. This joint structure may be formed at the same time as molding.

[0034]

As described above, when the manhole repairing method of the present invention is used, the swelling does not occur at least without the work that requires a long time to complete, such as stopping the water leakage and correcting the irregularities of the inner wall surface. It is possible to form a lining layer that does not cause a crack and has a sufficient repair effect.

The manhole repair material of the present invention can be easily transformed into a small diameter state and placed in the manhole.

[Brief description of drawings]

FIG. 1 is a perspective view of a manhole repair material according to the present invention.

FIG. 2 is a sectional view showing a modified example of the manhole repairing material according to the present invention.

FIG. 3 is a cross-sectional view showing a state in the manhole before placing a manhole repair material.

FIG. 4 is a cross-sectional view showing a state where a cylindrical portion is arranged in a manhole.

FIG. 5 is a cross-sectional view showing a state in which a truncated cone-shaped portion is arranged inside a manhole.

FIG. 6 is an enlarged cross-sectional view showing a cured state of a room temperature curable epoxy resin for lining.

[Explanation of symbols]

1,1 'Manhole repair material 3 Cylindrical part 5, 5'Frusto-conical part 7, 9 Cutting part 11, 11', 13, 13 'Rib 15 Manhole 17 Bottom surface 19 Inner wall surface 21 Annular water stop projection 29 Room temperature hardening Acrylic resin (curable injection material) 37,49 Gap 39 Quick setting cement (seal material) 41 Room temperature curable acrylic resin (curable water blocking material) 43,51 Room temperature curable epoxy resin for lining (Room temperature curable for lining) Injection material)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 592185666 Kansei Industry Co., Ltd. 1-3-7 Kamigaga, Setagaya-ku, Tokyo (71) Applicant 000227124 3-3 Nihonbashi-honcho, Chuo-ku, Tokyo No. 6 (72) Inventor Isao Natsuhori Komaki City, Aichi Pref. 3600 Gyogaisha, Tokai Rubber Industry Co., Ltd. (72) Inventor Ko Ishihara 3600 Gyougai, Komaki City, Aichi Prefecture Tokai Rubber Industry Co., Ltd. (72) Inventor Shinya Uda 3600 Gyokutsuyama, Komaki City, Aichi Prefecture Tokai Rubber Industry Co., Ltd. (72) Inventor Shuichi Takahashi 4203-1, Komaki, Kochi City, Aichi Prefecture Tokai Kasei Co., Ltd. (72) Inventor Yutaka Tano 12-2 Nihonbashi Odenmacho, Chuo-ku, Tokyo Nisso Yuka Kogyo Co., Ltd. (72) Inventor Katsumi Nakamura Setagaya-ku, Tokyo Yoga 1-7-3 KanKiyoshiko industry within Co., Ltd. (72) inventor Kato Keiki Nihonbashi, Chuo-ku, Tokyo Honcho 3-3-6 days Cao Shoji Co., Ltd. in

Claims (14)

[Claims] 1. A manhole repair method for lining and repairing a manhole, wherein a thin plastic repair material is placed in the manhole so as to cover the inner wall surface with a gap, and thereafter, the inner wall surface and this inner wall A method of repairing a manhole, comprising filling a liquid room temperature-curable injection material for lining in the gap with the repair material and curing the same. 2. A manhole repair method for lining and repairing the inside of a manhole, wherein an annular water-stop projection having a diameter smaller than that of an inner wall surface is formed on the bottom surface of the manhole, and the annular water-stop projection and the inner wall surface are covered with a liquid After the curable injection material is poured and cured, it is placed in the manhole by placing the thin repair material made of plastic on the cured injection material cured so as to cover the inner wall surface with a gap, Thereafter, a manhole repairing method is characterized in that the space between the inner wall surface and the repairing material is filled with a liquid room-temperature chilling-type injectable filling material and then cured. 3. A liquid curable water-stopping material is injected into the lower end of the gap between the inner wall surface and the repair material to be cured, and then the room temperature curable injection material for lining is filled and cured. The manhole repairing method according to claim 1 or 2, which is characterized. 4. In order to prevent liquid leakage from the lower end of the repair material placed in a manhole, a seal is applied to the lower end of the repair material, and then the room temperature curable injection material for lining is filled or cured. The method of repairing a manhole according to claim 1, wherein the water blocking material is injected. 5. The repair material is a tubular body that covers the inner wall surface of the manhole, and is cut at one position in the vertical direction. The repair material is reduced in diameter so as to be in an overlapped state. 5. The manhole repairing method according to claim 1, 2, 3 or 4, wherein the overlapped state is released and the manhole is placed in the manhole. 6. The outer surface of the tubular body is provided with a plurality of longitudinally extending gap forming ribs in the circumferential direction, and the repair material is provided so that the ribs are pressed against the inner wall surface of the manhole. The manhole repair method according to claim 5, wherein the manhole repair method is arranged in a manhole. 7. The cylindrical body as the cylindrical body,
The manhole repairing method according to claim 5 or 6, characterized in that a truncated cone-shaped tubular body placed on an upper end of the cylindrical tubular body is used. 8. The bending elastic modulus of the tubular body is 100 kg /
The manhole repairing method according to claim 5, 6 or 7, characterized in that it is not less than mm ^{2 and not} more than 1500 kg / mm ² . 9. The gap between the inner wall surface and the repair material is 2 mm or more and 10 mm or less.
The manhole repair method according to 3, 4, 5, 6, 7 or 8. 10. The kinematic viscosity of the room temperature curable injectable material for lining is 3000 cSt or less at 25 ° C., according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9. Manhole repair method. 11. The room-temperature-curable injection material for lining is one of an epoxy resin, an acrylic resin, and an unsaturated polyester resin.
The manhole repair method according to 2, 3, 4, 5, 6, 7, 8, 9, or 10. 12. A manhole repair material used for a method of lining and repairing a manhole, wherein a longitudinal cut portion is provided at one location of a plastic cylindrical body molded so as to cover an inner wall surface of the manhole. A manhole repair material characterized by this. 13. The manhole repair material according to claim 12, wherein a plurality of longitudinally extending gap forming ribs are provided on the outer surface of the cylindrical body. 14. The manhole repair material according to claim 12, wherein the tubular body is formed of a cylindrical portion and a frustoconical portion placed on an upper end of the cylindrical portion.