Gap repair method

Abstract

To repair a gap while removing a foreign substance influence even if the gap exists within a concrete structure and its inside may have the foreign substance with flowability.SOLUTION: A gap filler according to the present invention is to fill a gap that exists in a concrete structure and that may assume the existence of a foreign substance with flowability in a hollow part. The gap filler includes a normal temperature curable resin. The viscosity of the resin at 25°C is 80% or more of the viscosity of the assumed foreign substance at 25°C.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a gap filling material and a gap repair method. [Background technology]

[0002] Conventionally, concrete structures have often been used as the framework of various manufacturing facilities and buildings. Such concrete structures may develop cracks or other gaps on their surfaces due to the installation environment, deterioration over time, etc. If such gaps are left unattended, they will lead to a decrease in the strength of the concrete structure, and therefore various techniques have been proposed for repairing such gaps.

[0003] For example, Patent Document 1 below proposes a geopolymer for use in repairing cracks in concrete and repairing cross sections. Patent Document 2 below also proposes a technique for stopping water leakage from joints in concrete structures by filling the joints with wool and then injecting and hardening a waterproofing agent. Patent Document 3 below also proposes a repair material used to repair gaps at the boundary between soil and concrete slopes, and a repair method using such a repair material. The techniques disclosed in Patent Documents 1 to 3 can be said to be techniques for repairing gaps visible from the outside that exist in concrete structures. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-163196 [Patent Document 2] Japanese Patent Application Publication No. 2019-178485 [Patent Document 3] Japanese Patent Publication No. 2020-133215 Summary of the Invention [Problem to be solved by the invention]

[0005] Here, concrete structures may have not only gaps that can be seen from the surface of the structure, but also gaps that were formed inside the concrete structure during manufacturing or other processes and that the person in charge of managing the concrete structure may not be aware of. Therefore, there is a demand for technology that can repair gaps even if they exist inside a concrete structure.

[0006] Furthermore, depending on the installation environment of the concrete structure, it is anticipated that various foreign objects (e.g., foreign objects with fluidity) may enter the hollow portions of the gaps present inside the concrete structure through minute holes or cracks present in the concrete structure. The repair materials disclosed in the above Patent Documents 1 to 3 contain various resins. Therefore, it is important to remove foreign objects from gaps, as some foreign objects may hinder the hardening of the resin used as the repair material. However, it is anticipated that removing foreign objects from gaps present inside the concrete structure will be difficult.

[0007] As described above, there is a need for technology that will enable the repair of gaps that exist inside concrete structures and that may contain fluid foreign matter while eliminating the effects of such foreign matter.

[0008] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a gap filling material and a gap repair method that can repair gaps that exist inside concrete structures and that may contain fluid foreign matter while eliminating the effects of such foreign matter. [Means for solving the problem]

[0009] In order to solve the above problems, the inventors conducted extensive research and came up with the idea that if it were possible to fill the gap with gap filler while flushing out any foreign matter that may be present inside the gap, it would be possible to repair the gap while eliminating the effects of the foreign matter. Based on this idea, further research was conducted into techniques that would enable repairing gaps that exist inside concrete structures, and as a result, the inventors came up with the present invention, as described below. The gist of the present invention, which has been completed based on the above-mentioned concept, is as follows.

[0010] (1) A gap filler for filling gaps that exist in a concrete structure and in which the presence of a fluid foreign object in the hollow portion is expected, the gap filler containing a room temperature curing resin, the viscosity of the resin at 25°C being 80% or more of the viscosity of the expected foreign object at 25°C. (2) The gap filler according to (1), wherein the compressive strength of the gap filler after 72 hours of curing is 18 MPa or more. (3) The gap filler according to (1) or (2), wherein the resin is an epoxy resin. (4) A gap repair method for repairing gaps that exist in a concrete structure and in which the presence of a fluid foreign object in the hollow portion may be expected by filling the gap with a gap filler, the gap repair method comprising the steps of: inspecting the concrete structure by at least one of cavity investigation and non-destructive testing to identify the location of the gap; forming an opening in the concrete structure with a check valve that reaches the identified gap to serve as an injection port for the gap filler; pressing in the gap filler through the injection port, using a gap filler that contains a room temperature curing resin and whose viscosity at 25°C is 80% or more of the viscosity at 25°C of the expected foreign object; and curing the gap filler for 72 hours or more after pressing in the gap filler. (5) The gap repair method according to (4), wherein in the pressurizing step, the gap filler is pressurized at a pressure of 10 MPa or more and less than 50 MPa. (6) A gap repair method according to (4) or (5), wherein in the press-fitting step, additional openings with check valves are formed until the gap filler can be press-fitted. (7) A gap repair method described in any one of (4) to (6), further comprising an outlet forming step of forming an opening in the concrete structure other than the injection port that reaches the gap, to serve as an outlet for the foreign matter. (8) The gap repair method according to any one of (4) to (7), which is carried out on a gap having a maximum width of the hollow portion of 10 mm or less. (9) The gap repair method according to any one of (4) to (8), wherein the compressive strength of the gap filler after curing for 72 hours is 18 MPa or more. (10) The gap repair method according to any one of (4) to (9), wherein the resin is an epoxy resin. [Effects of the Invention]

[0011] As described above, according to the present invention, even if a gap exists inside a concrete structure and there is a possibility that a fluid foreign object may be present inside the gap, it is possible to repair the gap while eliminating the influence of such foreign object. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is an explanatory diagram for explaining gaps that may exist inside a concrete structure. [Figure 2] FIG. 1 is an explanatory diagram for explaining a test specimen used in verifying a gap filling material. [Figure 3] 1 is a flowchart illustrating a gap repair method according to an embodiment of the present invention. [Figure 4] 4A to 4C are explanatory diagrams for explaining a gap repair method according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0014] (Regarding gaps that may exist inside concrete structures) First, gaps that may exist inside a concrete structure will be described with reference to Fig. 1. Fig. 1 is an explanatory diagram for explaining gaps that may exist inside a concrete structure.

[0015] As shown schematically in Figure 1, gaps may form inside concrete structures during manufacturing. Furthermore, depending on the environment to which the concrete structure is exposed, gaps may also appear after the fact. For example, production lines in the steel industry contain many different heavy pieces of equipment, and extremely high loads are applied continuously or intermittently to the concrete structures that form their frameworks. Therefore, these loads may cause gaps to form inside the concrete structure that were not intended by the structure's manager.

[0016] For example, continuous casting lines used in the steel industry are equipped with equipment called a ladle turret. This ladle turret is equipment for continuously pouring molten steel into a tundish, and although it depends on the scale of the continuous casting line, multiple ladles holding molten steel in the order of tens to hundreds of tons are arranged in the ladle turret. When the volume of molten steel held in one ladle becomes low, the ladle turret is put into operation to place a new ladle above the tundish. When the inventors inspected this equipment, they found that there were minute gaps (the maximum width W of the gap shown in Figure 1) inside the concrete structure that constitutes the frame of the equipment. MAX It was found that a crack of approximately 0.5 to 10.0 mm occurs.

[0017] Because the ladle turret described above is equipment that operates constantly, lubricating oils (oils with fluidity) such as grease are used on the moving parts to ensure smooth operation of the equipment. If gaps that occur during the operation of the equipment reach the surface of the concrete structure, the lubricating oil will enter the hollow parts of the gaps as foreign matter. In addition, since there may be minute pores on the surface of the concrete structure, even if the gaps that occur do not reach the surface of the concrete structure, the lubricating oil will enter the hollow parts of the gaps as foreign matter through the minute pores.

[0018] Furthermore, in the steel industry, it is common for manufactured steel to be cooled with a coolant such as water. Therefore, in concrete structures constructed in an environment where liquids such as water are present, water and other liquids can enter the hollow parts of gaps as foreign matter.

[0019] In addition to the fluid substances mentioned above, various fluid foreign substances such as seawater, rainwater, various types of water to be treated, and flammable liquids such as gasoline and diesel can get into the gaps in concrete structures that are exposed to various environments.

[0020] In view of the above circumstances, the present inventors have conducted extensive research into a technology that can fill gaps of approximately 0.5 to 10.0 mm, in which fluid foreign matter may be present in the hollow portion, with a gap filler while sweeping away the foreign matter. As a result, they have completed the gap filler and gap repair method described in detail below.

[0021] (About gap fillers) A gap filling material according to an embodiment of the present invention will be described in detail below with reference to Fig. 2. Fig. 2 is an explanatory diagram for explaining a test specimen used to verify the gap filling material.

[0022] <Verification using test specimens> The inventors first considered three types of gap filler (hereinafter sometimes abbreviated as "filler") for filling the above-mentioned gaps: resin, concrete, and mortar. Here, while concrete and mortar can be applied to gaps of a sufficiently wide width, they confirmed that they have difficulty filling gaps of about 10.0 mm in width as described above. Therefore, they confirmed that resin-based gap fillers are suitable for gaps of about 0.5 to 10.0 mm in width.

[0023] Next, a test specimen, as shown in Figure 2, was prepared to simulate gaps in a concrete structure. This test specimen consisted of a 500mm x 1000mm acrylic plate and a steel plate, spaced 3mm apart. Two sides of the specimen were sealed with acrylic plates, and an opening was drilled through the top acrylic plate at the right edge of the plate to serve as an injection port. The gap between the acrylic plates was then filled with grease (viscosity at 25°C: 42000 mPa·s) to simulate a foreign object. By injecting the target gap filler into this test specimen through the injection port, it was possible to visually observe how the gap filler spread through the top acrylic plate.

[0024] As a result of the inventors' investigations, they found that the relationship between the viscosity of the gap filler and the foreign matter (grease in this example) is important for the gap filler injected through the injection port to flush out the foreign matter. In other words, they found that if the viscosity of the gap filler is too low compared to the foreign matter, the gap filler will not be able to flush out the foreign matter. Therefore, the inventors changed the viscosity of the resin used as the gap filler (a room-temperature curing acrylic resin in this example) and observed how the gap filler expanded the gap.

[0025] As a result, when acrylic resins with viscosities of 500 [mPa·s] and 6000 [mPa·s] at 25°C were used as gap fillers, water paths formed in the grease, but they did not spread any further and were unable to push away the foreign grease.On the other hand, when acrylic resin with a viscosity of 40,000 [mPa·s] at 25°C was used as gap filler, the resin spread concentrically and was able to fully push away the foreign grease.

[0026] As a result of conducting such verification by varying the type and viscosity of the foreign matter filled into the gap, as well as the type and viscosity of the gap filler used, it was discovered that it is possible to flush out the foreign matter by using a resin as a gap filler that has a viscosity of 80% or more of the viscosity of the foreign matter at 25°C.

[0027] Here, the higher the viscosity of the gap filler, the better, as long as it is at least 80% of the viscosity of the foreign matter. On the other hand, when considering repair work on actual concrete structures, if the viscosity of the gap filler becomes too high, it is expected that it will become difficult to inject the gap filler into the gaps, even when the gap filler is pressed in using a pump. From the above perspective, it has become clear that the viscosity of the gap filler to be used should be determined taking into account the capacity of the pump or other equipment available for injection.

[0028] Next, using the above test specimens, grease, and gap filler, we verified whether the injected gap filler would harden after curing. The results showed that by curing for 72 hours or more after filling the gap filler, it was possible for it to harden to a compressive strength of 18 MPa or more, equivalent to that of concrete.

[0029] <Gap filling material> Based on the above verification results, the inventors have come up with the following gap filling material according to this embodiment.

[0030] That is, the gap filler according to this embodiment is intended to fill gaps in concrete structures where fluid foreign matter may be present in the hollow portion. This gap filler contains a room temperature curing resin, and the viscosity of this resin at 25°C is 80% or more of the viscosity of the foreign matter at 25°C.

[0031] Here, there are no particular limitations on the method for identifying foreign matter that may be present in the hollow portion of the gap, and it can be easily estimated from the installation environment of the concrete structure in question, etc., and it is highly likely that it is a fluid substance adhering to the surface of the concrete structure. In addition, by carrying out a known inspection method such as a boring inspection on the concrete structure, it is possible to identify any foreign matter that may be present in advance.

[0032] If foreign matter can actually be collected by boring inspection or the like, it is possible to identify its viscosity by measuring the collected foreign matter with a known viscosity measuring device. Even if it is not possible to collect actual foreign matter, it is thought that the viscosity can be estimated if its constituent components are identified.

[0033] The resin used as the gap filler is a room-temperature curing resin. By using a room-temperature curing resin, when the gap filler is filled into the gaps of a concrete structure, the gap filler can be cured to a sufficient compressive strength by curing. An example of such a room-temperature curing resin is an epoxy resin. In addition to room-temperature curing resins, it is also possible to use grout, which is a mixture of water and cement.

[0034] The viscosity of the resin (at 25°C) is set to 80% or more of the viscosity of the expected foreign matter, as described above. By controlling the resin components to achieve this viscosity, it becomes possible to fill the resin while pushing away even highly viscous foreign matter present in narrow gaps, for example, of about 0.5 to 10.0 mm. As a result, not only can it be possible to omit a cleaning process such as pre-cleaning foreign matter with a detergent, but it also becomes possible to fill gaps present inside concrete structures with the resin while pushing away foreign matter.

[0035] The viscosity of the resin is preferably 85% or more, and more preferably 90% or more, of the viscosity of the expected foreign matter. Meanwhile, the higher the viscosity of the resin, the better, and it may be 100% or more of the viscosity of the expected foreign matter. However, since the viscosity of the resin that can be injected also depends on the capacity of the pump used for injection, it is preferable to use a resin that exhibits a viscosity that satisfies the above-mentioned conditions within the capacity of the pump used. The viscosity of the resin can be measured using various known viscosity measuring devices.

[0036] Furthermore, the compressive strength of such gap filler after 72 hours of curing is preferably 18 MPa or more. A compressive strength of 18 MPa or more after curing means that the hardened gap filler exhibits compressive strength equivalent to that of concrete, enabling more robust repair of concrete structures. The compressive strength of the gap filler after curing can be controlled to a desired state by adjusting the type of resin contained in the gap filler before curing, the compounding ratio of the curing agent, etc. The compressive strength of the gap filler after 72 hours of curing is more preferably 21 MPa or more. Meanwhile, there is no particular upper limit for the compressive strength of the gap filler after 72 hours of curing. However, if the compressive strength after curing becomes too high, the solidified gap filler may become brittle, raising concerns about plastic fracture when subjected to repeated loads. To prevent such plastic fracture, the compressive strength of the solidified concrete after curing is generally set to, for example, 100 MPa or less. Therefore, the compressive strength of the solidified gap filler after 72 hours of curing is preferably 100 MPa or less, and more preferably 60 MPa or less. The compressive strength can be determined by measuring the solidified gap filler after 72 hours of curing using a compression tester in accordance with JIS K7181 (2011).

[0037] (How to repair gaps) Next, a gap repair method according to this embodiment using the gap filler as described above will be described in detail with reference to Figures 3 and 4. Figure 3 is a flow chart for explaining the gap repair method according to this embodiment, and Figure 4 is an explanatory diagram for explaining the gap repair method according to this embodiment.

[0038] The gap repair method according to this embodiment is a method for repairing gaps that exist in concrete structures and in which the presence of fluid foreign matter in the hollow portion may be expected, by filling such gaps with a gap filler.

[0039] 3, the gap repair method includes at least an injection port forming step (step S11), a press-fitting step (step S15), and a curing step (step S17). Furthermore, the gap repair method according to this embodiment may further include an outflow port forming step (step S13) between the injection port forming step (step S11) and the press-fitting step (step S15), as needed. These steps will be described in detail below.

[0040] <Injection port formation process> The injection port forming step (step S11) according to this embodiment is a step in which, after identifying the position of the gap by at least one of cavity investigation and non-destructive testing, an opening with a check valve that reaches the identified gap is formed in the concrete structure to serve as an injection port for the gap filler. By providing this injection port forming step, it is possible to ensure that the gap filler according to this embodiment reaches the gap.

[0041] Here, the cavity investigation described above is not particularly limited, and various methods for investigating the presence or absence of cavities in concrete structures, including core boring, can be used. Furthermore, the non-destructive testing method described above is also not particularly limited, and various known testing methods can be used as long as they can detect gaps that may exist inside a concrete structure. Examples of such non-destructive testing methods include ultrasonic testing, electromagnetic radar testing, and impact acoustic wave testing. By performing both the cavity investigation and the non-destructive testing method, it is possible to more accurately detect the location of gaps that exist inside a concrete structure.

[0042] It is also important to provide an opening with a check valve as the injection port, because in order to inject a high-viscosity gap filler having a viscosity close to that of foreign matter, such as the gap filler according to this embodiment, even into a narrow gap of, for example, about 0.5 to 10.0 mm, it is important to pressurize the gap filler.

[0043] The size of the opening to be provided is not particularly limited, and may be set appropriately depending on the press-fitting conditions in the press-fitting step described below.

[0044] <Outlet formation process> The outflow outlet forming step (step S13) according to this embodiment is a step that is provided as needed. The outflow outlet forming step is a step of forming an opening in the concrete structure, separate from the injection port that reaches the gap, to serve as an outlet for foreign matter.

[0045] Not all hollow portions of gaps present inside a concrete structure necessarily contain fluid foreign matter. Furthermore, even if the location of a gap is identified by non-destructive testing in the above-described injection port formation process, there is a possibility that an opening leading to the outside exists in a gap outside the inspection range, or that a gap present within the inspection range is connected to another gap outside the inspection range. Therefore, even if an outflow port is not formed, it is possible to repair a concrete structure until it has sufficient strength as a concrete structure. For these reasons, the outflow port formation process according to this embodiment is a process that is provided as needed.

[0046] Here, the size of the opening to be provided is not particularly specified and may be set appropriately.

[0047] Furthermore, the timing of carrying out the outflow port formation process may be determined by observing the state of injection of the gap filler in the press-fitting process described later, and may be determined when it becomes difficult to inject the gap filler, or may be carried out in parallel with the press-fitting process described later.

[0048] 3, the case where the outflow port forming step (step S13) is performed after the injection port forming step (step S11) is described, but the present invention is not limited to this flow. For example, the injection port forming step may be performed after the outflow port forming step, or the injection port forming step and the outflow port forming step may be performed in parallel.

[0049] <Press-fitting process> The press-in step (step S15) according to this embodiment is a step of press-injecting a gap filler containing a room-temperature curing resin, as explained above, in which the viscosity of the resin at 25° C. is 80% or more of the viscosity of the expected foreign matter at 25° C., through the formed injection port. This makes it possible to fill the hollow portion with the gap filler while pushing out the foreign matter, even in gaps in which fluid foreign matter may be present.

[0050] In this press-fitting step, the gap filler is preferably pressed in at a pressure of 10 MPa or more and less than 50 MPa. By pressing the previously mentioned gap filler under such pressure, it becomes possible to fill even narrow gaps, for example, about 0.5 to 10.0 mm, with the gap filler while pushing out any foreign matter that may be present in the hollow portion of the gap.

[0051] In this injection process, additional injection ports with check valves may be formed until the gap filler can be injected. This allows the gap filler to be injected into the target gap even if it is not possible to inject the gap filler from the originally intended injection port for some reason, thereby making it possible to repair the concrete structure.

[0052] <Curing process> The curing step (step S17) according to this embodiment is a step of curing the gap filler for 72 hours or more after the gap filler is pressed in, thereby hardening the pressed-in gap filler. By undergoing this curing step, the gap filler filled in the gaps will exhibit a compressive strength of, for example, 18 MPa or more, making it possible to improve the strength of the concrete structure.

[0053] The gap repair method using the gap filler according to this embodiment has been described in detail above. [Example]

[0054] The gap filler and gap repair method according to the present invention will be specifically described below with reference to examples and comparative examples. Note that the examples shown below are merely examples of the gap filler and gap repair method according to the present invention, and the gap filler and gap repair method according to the present invention are not limited to the following examples.

[0055] In this test example, we focused on a ladle turret that was actually in operation as a concrete structure, and attempted to repair tiny gaps (approximately 0.5 to 10.0 mm) that had occurred in the ladle turret's frame using gap filler. In this ladle turret, gaps in the frame had created areas where horizontality was not guaranteed. Furthermore, since the ladle turret requires smooth operation of its mechanism, a large amount of grease is used in the moving parts. Therefore, there is a possibility that such grease may be present in gaps that have occurred inside the frame. The viscosity of the grease used for ladle turret maintenance was separately confirmed, and was found to be 42,000 mPa·s at 25°C.

[0056] The ladle turret body was inspected for cavities by core boring and ultrasonic testing to detect the locations of gaps within the body. In this test example, three gaps that were sufficiently spaced apart were selected, and various gap filling materials were pressed into these gaps.

[0057] Since the suspected foreign substance was grease with a viscosity of 42,000 mPa·s at 25°C, three types of resin were prepared as gap fillers: a resin (Alphatec 370, manufactured by Alpha Industries Co., Ltd.) with a viscosity of 500 mPa·s at 25°C (1.2% of the viscosity of grease); a resin (Alpron W221, manufactured by Nichibei Resin Co., Ltd.) with a viscosity of 6,000 mPa·s at 25°C (14% of the viscosity of grease); and a resin (Everbond EP-100, manufactured by Daiflex Co., Ltd.) with a viscosity of 40,000 mPa·s at 25°C (95% of the viscosity of grease). All of these resins are commercially available, room-temperature curing epoxy resins. Furthermore, a solidified sample of Everbond EP-100 was separately prepared, and its compressive strength was measured after 72 hours of curing; the compressive strength was 54.1 MPa.

[0058] An inlet with a check valve (maximum pressure resistance 25 MPa) and an outlet were provided for each of the three selected gaps. The pump used for injection was a commercially available pump with a maximum pressure of 50 MPa. The pump was installed at each injection port, and the gap filler was injected at a pressure of 10 MPa or more but less than 20 MPa. The mass of the injected resin was approximately 150 kg, of which about 40 kg leaked through the gaps, leaving a net filling amount of approximately 110 kg.

[0059] After the resin was pressed in, no outflow of grease was observed from the outlet installed in the gap into which a resin with a viscosity of 500 mPa·s at 25°C was injected, and from the outlet installed in the gap into which a resin with a viscosity of 6000 mPa·s at 25°C was injected. On the other hand, outflow of grease was observed from the outlet installed in the gap into which a resin with a viscosity of 40000 mPa·s at 25°C was injected. From these results, it can be inferred that in the cases of resins with a viscosity of 500 mPa·s at 25°C and resins with a viscosity of 6000 mPa·s at 25°C, the gap filler was pressed in without forcing out the grease.

[0060] Furthermore, when the horizontality of the frame was checked again after 72 hours of curing, no improvement in horizontality was observed in the gaps where resin with a viscosity of 500 mPa·s at 25° C. and resin with a viscosity of 6000 mPa·s at 25° C. were injected, while improvement in horizontality was observed in the gaps where resin with a viscosity of 40000 mPa·s at 25° C. was injected. These results demonstrate that the gap repair method according to this embodiment can be used to repair the frame of a ladle turret.

[0061] Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

Claims

1. A gap repair method for repairing a gap that exists in a concrete structure and in which the presence of a foreign object having a predetermined viscosity and fluidity in a hollow portion is expected, by filling the gap with a gap filler, an injection port forming step of inspecting the concrete structure by at least one of cavity investigation and non-destructive testing to identify the position of the gap and identify any foreign matter that may be present in the hollow portion of the gap, and then forming an opening with a check valve in the concrete structure that reaches the identified gap, and using the opening as an injection port for the gap filler; a pressure-injecting step of using a gap filler containing a room temperature curing resin, the viscosity of which at 25°C is 80% or more of the viscosity of the expected foreign matter at 25°C, as the gap filler, and pressure-injecting the gap filler through the injection port; a curing step of curing the gap filling material for 72 hours or more after pressing the gap filling material into the cavity; A gap repair method comprising:

2. The gap repair method according to claim 1 , wherein in the pressurizing step, the gap filler is pressurized at a pressure of 10 MPa or more and less than 50 MPa.

3. The gap repair method according to claim 1 or 2, wherein in the press-fitting step, the openings with check valves are additionally formed until the gap filler can be press-fitted.

4. The gap repair method according to any one of claims 1 to 3, further comprising an outlet forming step of forming an opening in the concrete structure other than the injection port that reaches the gap, as an outlet for the foreign matter.

5. The gap repair method according to any one of claims 1 to 4, which is carried out on a gap having a maximum width of the hollow portion of 10 mm or less.

6. The gap repair method according to any one of claims 1 to 5, wherein the compressive strength of the gap filler after 72 hours of curing is 18 MPa or more.

7. The gap repair method according to any one of claims 1 to 6, wherein the resin is an epoxy resin.

8. A gap repair method described in any one of claims 1 to 7, wherein the foreign matter is a lubricating oil having a predetermined viscosity at 25°C.

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