Sealant, structure, method for constructing and repairing a structure

Abstract

To provide a technique for improving at least one of strength and durability of a structure.SOLUTION: A sealing material comprises at least one of a first compound capable of generating cations constituting poorly soluble salt and a second compound capable of generating anions constituting poorly soluble salt, and poorly soluble material that serves as a nucleus for precipitating a poorly soluble salt from at least one of cations and anions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a sealant for constructing a structure, a structure including the sealant, and a method for constructing and repairing the structure. [Background technology]

[0002] Numerous structures are being constructed not only on land, but also underwater and underground. Some structures, such as tunnels and underground disposal sites for radioactive waste, must be built at considerable depths underground. Cavities and cracks always exist in underground bedrock, through which groundwater seeps out. However, the deeper the underground cavity being excavated, the more difficult it becomes to avoid sudden seepage due to an increase in pore water pressure. Therefore, in order to safely utilize underground environments and cavities over the long term, it is essential to develop technology that can stop groundwater from leaking for a long period of time, even under high pore water pressure. It is also necessary to improve the durability of the structural materials that make up the structures. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-1365 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, as described in Patent Document 1, for example, an injection pipe is inserted into an injection hole formed in a crack, and its outlet is positioned facing the crack. A highly permeable cement-based crack injection agent is then injected into the crack, which hardens inside the crack to seal the water.

[0005] However, it has not been fully verified whether the watertightness of these conventional technologies and the durability of existing structures can be maintained for long periods of time, such as several decades. There is a need to develop technologies that can maintain the strength and durability of watertight areas and structural materials over the long term.

[0006] The present disclosure has been made in view of such problems, and its purpose is to provide a technique for improving at least one of the strength and durability of a structure. [Means for solving the problem]

[0007] In order to solve the above problems, a sealing material according to one embodiment of the present disclosure comprises at least one of a first compound capable of generating cations that constitute a poorly soluble salt and a second compound capable of generating anions that constitute a poorly soluble salt, and a poorly soluble substance that serves as a nucleus for precipitating the poorly soluble salt from at least one of the cations and anions.

[0008] Another aspect of the present disclosure is a structure comprising a structure and a sealant present in at least one of voids and a surface of the structure, the sealant comprising a hardly soluble core and a hardly soluble salt present in the vicinity of the core.

[0009] Yet another aspect of the present disclosure is a method for constructing a structure, comprising the step of providing a sealant in at least one of a cavity and a surface of a structure, the sealant including at least one of a first compound containing a cation that constitutes a poorly soluble salt and a second compound containing an anion that constitutes a poorly soluble salt, and a poorly soluble substance that serves as a nucleus for precipitating the poorly soluble salt from at least one of the cation and the anion.

[0010] Yet another aspect of the present disclosure is a repair method, which comprises applying the above-described sealant to a repaired portion of a structure. [Effects of the Invention]

[0011] According to the present disclosure, at least one of the strength and durability of a structure can be improved. [Brief explanation of the drawings]

[0012] [Figure 1]1 is a flowchart showing the steps of a method for constructing a structure according to an embodiment. [Figure 2] FIG. 1 is a diagram schematically illustrating a cross section of a structure according to an embodiment. [Figure 3] 3(a) and 3(b) are diagrams schematically showing a cross section of a sealing material according to an embodiment. [Figure 4] 1 is a flowchart showing the steps of a method for repairing a structure according to an embodiment. [Figure 5] FIG. 1 shows the particle size distribution of a limestone standard sample. [Figure 6] 6(a), (b), and (c) are polarizing microscope photographs of the flakes of Examples 1 to 3 at 200 magnifications, respectively. [Figure 7] 7(a), (b), (c), (d), (e), and (f) are electron microscope photographs of the cross sections of the samples of Examples 1 to 3. DETAILED DESCRIPTION OF THE INVENTION

[0013] In this disclosure, a technique for closing voids such as cracks and fissures in a structure to improve the strength, corrosion resistance, and durability of the structure will be described.

[0014] The sealing material according to an embodiment of the present disclosure comprises at least one of a first compound capable of generating cations that constitute a poorly soluble salt and a second compound capable of generating anions that constitute a poorly soluble salt, and a poorly soluble substance that serves as a nucleus for precipitating the poorly soluble salt from at least one of the cations and anions.

[0015] When the sealant is kneaded with water or a liquid agent, if necessary, and applied to the voids or surfaces of a structure that forms the structure of a structure, if the sealant contains a first compound, cations that form a poorly soluble salt are eluted from the first compound, and if the sealant contains a second compound, anions that form a poorly soluble salt are eluted from the second compound. If the sealant contains both the first compound and the second compound, a poorly soluble salt is generated from the eluted cations and anions. If the sealant contains the first compound, a poorly soluble salt is generated from the eluted cations and anions contained in the surrounding groundwater, etc. If the sealant contains the second compound, a poorly soluble salt is generated from the eluted anions and cations contained in the surrounding groundwater, etc. In this case, the poorly soluble substance contained in the sealant functions as a crystal nucleus, and the poorly soluble salt precipitates around the poorly soluble substance. This promotes the precipitation of the sparingly soluble salt, so that the sparingly soluble salt can be precipitated in situ to efficiently block the voids and surfaces of the structure before the dissolved cations and anions diffuse into the surroundings from the voids and surfaces of the structure, thereby improving the strength, corrosion resistance, and durability of the structure.

[0016] Both the first compound and the second compound may be present together in the sealant. For example, the first compound and the second compound may be present mixedly in the sealant. Both the first compound and the second compound may be present separately in the sealant. For example, at least one of the first compound and the second compound may be encapsulated in a capsule or the like and contained in the sealant. The capsule may be made of a material that dissolves in water or the like.

[0017] The sealant may further include a base material containing at least one of the first compound and the second compound and a sparingly soluble salt. The base material may be a material that has fluidity that allows it to be injected into voids in a structure, etc., and that hardens after being injected by a chemical reaction such as hydration or polymerization, or by heating, cooling, drying, light, or the like. The base material may be, for example, cement, mortar, concrete, or the like; a thermosetting resin such as an epoxy resin; a thermoplastic resin such as an acrylic resin; or a mixture thereof. Note that the sealant in a solidified state of the base material may be inserted into voids in a structure, etc.

[0018] The hardly soluble salt may be any salt that has sufficiently low solubility in water at the temperature of the environment in which the sealant is installed, is chemically stable, and does not pollute the surrounding natural environment. Examples of such salts include carbonates such as calcium carbonate, magnesium carbonate, and iron(II) carbonate (siderite, siderite), double salts such as calcium magnesium carbonate (CaMg(CO3), dolomite, dolomite), and sulfates such as calcium sulfate. The solubility of calcium carbonate, which depends on the crystal structure, is approximately 0.0015 g / 100 g water at 20°C, the solubility of magnesium carbonate is 0.039 g / 100 g water at 20°C, the solubility of iron(II) carbonate is 0.00006554 g / 100 g water at 20°C, and the solubility of calcium sulfate is 0.24 g / 100 g water at 20°C. The solubility of the poorly soluble salt in 100 g of water at 20°C may be, for example, 0.3 or less, more preferably 0.04 or less, and even more preferably 0.002 or less. The solubility of the poorly soluble salt needs only to be lower than the solubility of the compound that is the main component of the base material. The poorly soluble salt may be selected appropriately depending on the environment in which the sealant is to be disposed. For example, calcium carbonate can be converted into calcium bicarbonate, which has a relatively high solubility in water, by a chemical reaction with carbon dioxide. Therefore, when the sealant is to be disposed in an environment with a relatively high concentration of carbon dioxide, the sealant may contain a first compound and a second compound for supplying ions that form a poorly soluble salt other than calcium carbonate.

[0019] When calcium carbonate is precipitated as a sparingly soluble salt, the first compound may be any compound capable of generating calcium ions, having sufficiently high solubility in water at the temperature of the environment in which the sealant is to be disposed, and not polluting the surrounding natural environment. Examples of the first compound include calcium chloride (CaCl), calcium nitrate (Ca(NO), and calcium bicarbonate (Ca(HCO).

[0020] When calcium carbonate is precipitated as a sparingly soluble salt, the second compound may be any compound capable of generating at least one of carbonate ions and bicarbonate ions, having sufficiently high solubility in water at the temperature of the environment in which the sealant is to be disposed, and not polluting the surrounding natural environment. The second compound may be, for example, sodium bicarbonate (NaHCO3), potassium bicarbonate (KHCO3), ammonium bicarbonate (NH4HCO3), etc.

[0021] The base material of the sealant may contain a sparingly soluble compound composed of the same cations or anions as the sparingly soluble salt. For example, the sparingly soluble salt and the sparingly soluble compound may be a sparingly soluble salt of calcium. More specifically, the sparingly soluble salt may be calcium carbonate, and the sparingly soluble compound may be calcium hydroxide or calcium sulfate, which are major components of cement, concrete, etc. This allows the calcium ions supplied from the first compound to shift the dissolution equilibrium of the sparingly soluble compound in the sealant toward the solid side, even if groundwater, rainwater, or the like penetrates into the sealant, such as concrete, thereby preventing calcium ions from leaching out of the base material. This prevents the calcium ions in the base material from gradually leaching out and being lost, which would cause microvoids or cracks to form inside the base material and thereby reduce the strength of the sealant. This allows the strength of the sealant to be maintained over a long period of time, thereby dramatically improving the durability of structures.

[0022] The hardly soluble material may be any material that has sufficiently low solubility in water at the temperature of the environment in which the sealant is to be disposed, is chemically stable, and does not pollute the surrounding natural environment, and may be, for example, carbonates such as calcium carbonate, magnesium carbonate, and iron (II) carbonate (siderite, siderite), double salts such as calcium magnesium carbonate (CaMg(CO3)2, dolomite, dolomite), sulfates such as calcium sulfate, metal hydroxides such as iron hydroxide, metals such as iron, minerals such as sand and rock, etc. The hardly soluble material may be the same as or different from the hardly soluble salt to be precipitated.

[0023] The poorly soluble material may be a powder. The particle size of the poorly soluble material may be, for example, 40 μm or less, 39 μm or less, 38 μm or less, 37 μm or less, 36 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, 19 μm or less, 18 μm or less, 17 μm or less, 16 μm or less, 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, or 10 μm or less. The particle size of the poorly soluble material may be, for example, 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, 10 μm or more, 11 μm or more, 12 μm or more, 13 μm or more, 14 μm or more, or 15 μm or more. The particle size of the hardly soluble substance may be measured by a method such as dynamic light scattering, laser diffraction / scattering, image imaging, or gravitational sedimentation.

[0024] The amount of the hardly soluble substances may be, for example, 0.001% or more, 0.002% or more, 0.003% or more, 0.004% or more, 0.005% or more, 0.01% or more, 0.02% or more, 0.03% or more, 0.04% or more, 0.05% or more, 0.1% or more, 0.2% or more, 0.3% or more, 0.4% or more, 0.5% or more, or 1.0% or more based on the total weight of the sealant. The amount of the hardly soluble substances may be, for example, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.1% or less, 0.09% or less, 0.08% or less, 0.07% or less, 0.06% or less, or 0.05% or less based on the total weight of the sealant.

[0025] The first compound and the second compound may be contained in the sealing material as powders so that ions are easily eluted from the first compound and the second compound when the sealing material is provided on a structure.

[0026] The sealant may include an ion exchange resin to which at least one of the cations and anions constituting the sparingly soluble salt is adsorbed. In this case, the ion exchange resin can be selected or designed to release ions in an appropriate amount and at an appropriate supply rate depending on the type of ions to be supplied and the components, amount, and pH of the chemical substances dissolved in the groundwater surrounding the sealant.

[0027] At least one of the cations and anions constituting the sparingly soluble salt may be encapsulated in a capsule and contained in the sealant. The ions encapsulated in the capsule may be contained as at least one of a first compound and a second compound, or may be contained as an ion exchange resin to which the ions are adsorbed. In this case, too, the material, thickness, shape, etc. of the capsule can be selected or designed to release the ions in an appropriate amount and at an appropriate supply rate depending on the type of ions to be supplied and the components, amount, and pH of the chemicals dissolved in the groundwater surrounding the sealant.

[0028] FIG. 1 is a flowchart showing the steps of a method for constructing a structure according to an embodiment. First, a base material for a sealant, a first compound containing cations constituting a poorly soluble salt, a second compound containing anions constituting a poorly soluble salt, and a poorly soluble substance that serves as a nucleus for precipitating a poorly soluble salt from the cations eluted from the first compound and the anions eluted from the second compound are mixed (S12). Next, the mixture is injected, inserted, applied, and / or sprayed into at least one of the voids and the surface of the structure being constructed, thereby disposing the sealant in the voids and the surface of the structure (S14). When disposing the sealant in a void of a structure, a flowable sealant may be injected into the void, or a solidified sealant may be inserted into the void. When disposing the sealant on the surface of a structure, a flowable sealant may be applied to the surface, or a solidified sealant may be applied to the surface. When the flowable sealant is applied or sprayed onto the surface of the structure, the sealant may be injected into the voids at the same time.

[0029] The base material, the first compound, the second compound, and the hardly-soluble substance may be mixed on-site immediately before applying the mixture to the void or surface of a structure. Either the first compound or the second compound may be premixed with the base material, and the remaining components may be mixed with the mixture on-site. In this case, the hardly-soluble substance may also be premixed with the mixture. A mixture of the first compound and the base material and a mixture of the second compound and the base material may be mixed on-site. In this case, the hardly-soluble substance may be premixed with either mixture or mixed on-site. If the sealant does not contain the first compound, any two or more of the base material, the second compound, and the hardly-soluble substance may be premixed or mixed on-site. In this case, a hardly-soluble salt is generated from anions eluted from the second compound and cations contained in the surrounding groundwater, etc. If the sealant does not contain the second compound, any two or more of the base material, the first compound, and the hardly-soluble substance may be premixed or mixed on-site. In this case, a poorly soluble salt is produced from the cations eluted from the first compound and the anions contained in the surrounding groundwater.

[0030] FIG. 2 is a schematic cross-sectional view of an example of a structure according to an embodiment. The structure 5 shown in FIG. 2 is a structure that constitutes a wall separating a space, such as an underground cavity, a facility such as an underground disposal site, or a tunnel, from the surrounding bedrock. The structure 5 includes a structural element 6 that forms the structure of the structure 5, and a sealant 1 present in at least one of the voids and the surface of the structural element 6. The structural element 6 may be made of, for example, cement, mortar, concrete, or the like. The sealant 1 is disposed in the voids and the surface of the structural element 6. The structure according to the embodiment may be a building such as a house, a building, or a facility; a structure such as a tunnel, a dam, or a levee; or any building, structure, or construction installed on the ground, underground, underwater, or at the bottom of the sea.

[0031] FIG. 3 is a schematic cross-sectional view of a sealant according to an embodiment. FIG. 3(a) is a schematic cross-sectional view of the sealant 1 immediately after mixing the base material 2, the first compound 7, the second compound 8, and the poorly soluble substance 3. FIG. 3(b) is a schematic cross-sectional view of the sealant 1 immediately after cations have been eluted from the first compound 7 and anions have been eluted from the second compound 8. A poorly soluble salt 4 precipitates from the cations generated from the first compound 7, the anions generated from the second compound 8, and counterions contained in the surrounding groundwater. The poorly soluble salt 4 precipitates even in the absence of the poorly soluble substance 3, but precipitation of the poorly soluble salt 4 is promoted by crystal growth using the poorly soluble substance 3 as a crystal nucleus. In some cases, the poorly soluble salt 4 forms in contact with the poorly soluble substance 3. In other cases, the base material 2 adheres to the poorly soluble substance 3, and the poorly soluble salt 4 forms in contact with the adhered base material 2. Therefore, in the sealing material 1, the poorly soluble salt 4 is present at least in a position contacting the poorly soluble substance 3 and in a position near the poorly soluble substance 3. Even if the poorly soluble substance 3 and the poorly soluble salt 4 are the same compound, the poorly soluble substance 3 and the poorly soluble salt 4 can be distinguished from each other by differences in crystallinity, crystal orientation, etc.

[0032] The above explanation has been about a technology for sealing voids and surfaces of a structure under construction by applying a sealant to the voids and surfaces of the structure, but the technology of this embodiment can also be used to repair areas that need repair, such as voids in an existing structure.

[0033] FIG. 4 is a flowchart showing the steps of a repair method according to an embodiment. First, a base material of a sealant, a first compound, a second compound, and a hardly-soluble substance are mixed (S22). Next, the mixture is injected, inserted, applied, and / or sprayed into the repair area of ​​an existing structure, thereby disposing the sealant at the repair area of ​​the structure (S24). If the sealant does not contain the first compound, any two or more of the base material, the second compound, and the hardly-soluble substance may be mixed in advance or may be mixed on-site. In this case, a hardly-soluble salt is generated from anions eluted from the second compound and cations contained in the surrounding groundwater, etc. If the sealant does not contain the second compound, any two or more of the base material, the first compound, and the hardly-soluble substance may be mixed in advance or may be mixed on-site. In this case, a hardly-soluble salt is generated from cations eluted from the first compound and anions contained in the surrounding groundwater, etc.

[0034] [Example] An experiment was conducted to form a hardly soluble salt in a sample simulating the sealing material according to the embodiment.

[0035] [Sample preparation] Anhydrous CaCl2 reagent (Kishida Chemical, special grade) as the first compound and agar powder (Wako Pure Chemical Industries) as the base material were added to three 100 ml beakers in the following weight amounts. Example 1: CaCl (2.498 g) Agar (2.517 g) Example 2: CaCl (2.508 g) Agar (2.520 g) Example 3: CaCl (2.503 g) Agar (2.516 g) 50 ml of ultrapure water heated to approximately 80°C was added to each beaker, and CaCl2 and agar were dissolved. To evaluate the effect of calcium carbonate nuclei on calcium carbonate crystal growth, 0.0133 g and 0.103 g of limestone standard sample JLs-1 issued by the Geological Survey of Japan were added to Examples 2 and 3, respectively, as a difficult-to-dissolve substance that would serve as a crystal nucleus. This agar solution was transferred to a molding cup and allowed to cool and solidify.

[0036] Figure 5 shows the grain size distribution of the limestone standard sample JLs-1. In Figure 5, the bar graph shows the grain size histogram, and the line graph shows the cumulative frequency curve of grain size, both on the phi scale. The grain size of the limestone standard sample JLs-1 is generally in the range of 1.2 μm to 37.2 μm, with an average grain size of 3.31 μm.

[0037] [Reaction experiment] The agars of Examples 1 to 3 were floated in a saturated aqueous solution of sodium bicarbonate (103 g / L, 25°C), which was the second compound, and reacted for one week. The samples floated in the aqueous sodium bicarbonate solution at the beginning of the reaction, but sank into the solution as calcium carbonate crystals grew.

[0038] [Observation of reaction products] The agar was reacted for one week and then removed and dried for one day in a thermostatic chamber set at 60°C. The dried reaction product was solidified with instant adhesive, and thin sections were cut and observed under an electron microscope.

[0039] Figures 6(a), 6(b), and 6(c) are polarizing microscope photographs of thin sections of Examples 1 to 3 at 200x magnification, respectively. Figures 7(a), 7(b), 7(c), 7(d), 7(e), and 7(f) are electron microscope photographs of the cross sections of samples of Examples 1 to 3 at 150x magnification and 1000x magnification, respectively. Figures 7(c) and 7(d) are electron microscope photographs of the cross section of sample of Example 2 at 150x magnification and 1000x magnification, respectively. Figures 7(e) and 7(f) are electron microscope photographs of the cross section of sample of Example 3 at 150x magnification and 1000x magnification, respectively.

[0040] The particle size of the precipitated calcium carbonate in Example 1, which did not contain calcium carbonate as nuclei, was approximately 10 to 30 μm. The particle size of the precipitated calcium carbonate in Example 2, which contained approximately 0.01 g of a limestone standard sample, was approximately 5 to 15 μm. The particle size of the precipitated calcium carbonate in Example 3, which contained approximately 0.1 g of a limestone standard sample, was approximately 2 to 4 μm. The greater the amount of refractory matter that served as crystal nuclei, the smaller the crystal size of the calcium carbonate produced and the greater the amount of particle growth. The greater the amount of refractory matter that served as crystal nuclei, the more densely the particles grew, and the harder the sample was when cut with a knife.

[0041] In this way, it was shown that by adding a hardly soluble nanopowder to a sealant, finer calcium carbonate crystals grow almost uniformly, using the nanopowder as nuclei.

[0042] The present disclosure has been described above based on examples. These examples are merely illustrative, and it will be understood by those skilled in the art that various modifications are possible in the combination of the components and processing steps, and that such modifications are also within the scope of the present disclosure.

[0043] In the embodiment, a poorly soluble salt is precipitated around a poorly soluble material, but a poorly soluble compound other than salt may also be precipitated. In this case, the sealant may contain a compound that is easily soluble in water but reacts chemically with other compounds present in the environment in which the sealant is installed to produce a poorly soluble precipitate. For example, a sealant for a structure constructed underground near a volcano may contain a compound that generates zinc ions, which reacts with hydrogen sulfide present in the surrounding area to precipitate zinc sulfide.

[0044] An outline of one aspect of the present disclosure is as follows.

[0045] A sealant according to one embodiment of the present disclosure includes at least one of a first compound capable of generating cations constituting a poorly soluble salt and a second compound capable of generating anions constituting a poorly soluble salt, and a poorly soluble substance that serves as a nucleus for precipitating the poorly soluble salt from at least one of the cations and anions. This promotes the precipitation of the poorly soluble salt, thereby efficiently sealing cracks in a structure and improving the strength, corrosion resistance, and durability of the structure.

[0046] Both the first compound and the second compound may be present in the sealant, which promotes the precipitation of the sparingly soluble salt, thereby efficiently sealing cracks in the structure and improving the strength, corrosion resistance, and durability of the structure.

[0047] Both the first compound and the second compound may be present separately in the sealant, which can promote the precipitation of the sparingly soluble salt, thereby efficiently sealing cracks in the structure and improving the strength, corrosion resistance, and durability of the structure.

[0048] The sealant may further include a base material containing at least one of the first compound and the second compound and a sparingly soluble salt, thereby efficiently sealing cracks in the structure and improving the strength, corrosion resistance, and durability of the structure.

[0049] The hardly soluble substance may be a hardly soluble salt, which can promote precipitation of the hardly soluble salt, thereby efficiently sealing cracks in the structure and improving the strength, corrosion resistance, and durability of the structure.

[0050] The poorly soluble salt may be calcium carbonate, the first compound may be at least one of calcium chloride, calcium nitrate, and calcium bicarbonate, and the second compound may be at least one of sodium bicarbonate, potassium bicarbonate, and ammonium bicarbonate, thereby improving the strength, corrosion resistance, and durability of the structure.

[0051] The hardly soluble material may be in the form of a powder, which can promote the precipitation of the hardly soluble salt, thereby efficiently sealing cracks in the structure and improving the strength, corrosion resistance, and durability of the structure.

[0052] The sealant may include an ion exchange resin to which at least one of cations and anions is adsorbed, which promotes the precipitation of sparingly soluble salts, thereby efficiently sealing cracks in the structure and improving the strength, corrosion resistance, and durability of the structure.

[0053] A structure according to one aspect of the present disclosure includes a structure and a sealant present in at least one of voids and a surface of the structure, the sealant including a hardly-soluble core and a hardly-soluble salt present at least one of a position in contact with the core and a position near the core, thereby improving the strength, corrosion resistance, and durability of the structure.

[0054] The hardly soluble substance may be a hardly soluble salt, which can improve the strength, corrosion resistance, and durability of the structure.

[0055] The hardly soluble salt may be calcium carbonate, which can improve the strength, corrosion resistance, and durability of the structure.

[0056] A method for constructing a structure according to one aspect of the present disclosure includes applying a sealant to at least one of voids and surfaces of a structure, the sealant comprising at least one of a first compound containing a cation forming a poorly soluble salt and a second compound containing an anion forming a poorly soluble salt, and a poorly soluble substance that serves as a nucleus for precipitating the poorly soluble salt from at least one of the cation and the anion. This promotes the precipitation of the poorly soluble salt, thereby efficiently sealing cracks in the structure and improving the strength, corrosion resistance, and durability of the structure.

[0057] The hardly soluble substance may be a hardly soluble salt, which can promote precipitation of the hardly soluble salt, thereby efficiently sealing cracks in the structure and improving the strength, corrosion resistance, and durability of the structure.

[0058] The hardly soluble salt may be calcium carbonate, which can improve the strength, corrosion resistance, and durability of the structure.

[0059] A repair method according to one aspect of the present disclosure includes applying any one of the above sealants to a portion of a structure to be repaired, thereby efficiently sealing and repairing cracks and the like in the structure, thereby improving the strength, corrosion resistance, and durability of the structure. [Explanation of symbols]

[0060] 1 sealing material, 2 base material, 3 sparingly soluble substance, 4 sparingly soluble salt, 5 structure, 6 structure, 7 first compound, 8 second compound.

Claims

1. At least one of a first compound capable of generating a cation constituting a poorly soluble salt and a second compound capable of generating an anion constituting the poorly soluble salt; a hardly soluble substance serving as a nucleus for precipitating the hardly soluble salt from at least one of the cation and the anion; Equipped with The hardly soluble substance is different from the first compound and the second compound. Sealant.

2. The first compound and the second compound have higher solubility in water at the temperature of the environment in which the sealant is disposed than the poorly soluble salt. The sealant according to claim 1.

3. The first compound and the second compound have higher solubility in water than the poorly soluble compound at the temperature of the environment in which the sealant is disposed. The sealing material according to claim 1 or 2.

4. The composition further includes a matrix that encapsulates at least one of the first compound and the second compound and the poorly soluble salt. The sealing material according to any one of claims 1 to 3.

5. The hardly soluble substance is the hardly soluble salt. The sealing material according to any one of claims 1 to 4.

6. the poorly soluble salt is calcium carbonate, the first compound is at least one of calcium chloride, calcium nitrate, and calcium bicarbonate; The second compound is at least one of sodium bicarbonate, potassium bicarbonate, and ammonium bicarbonate. The sealing material according to any one of claims 1 to 5.

7. The hardly soluble substance is a powder. The sealing material according to any one of claims 1 to 6.

8. The particle size of the hardly soluble material is 40 μm or less. The sealing material according to claim 7.

9. An ion exchange resin on which at least one of the cations and the anions is adsorbed is provided. The sealing material according to any one of claims 1 to 8.

10. a structure; a sealant present in at least one of the voids and the surface of the structure; Equipped with The sealing material is At least one of a first compound capable of generating a cation constituting a poorly soluble salt and a second compound capable of generating an anion constituting the poorly soluble salt; a core made of a poorly soluble material different from the first compound and the second compound; the hardly soluble salt formed around the core; A structure comprising:

11. The hardly soluble substance is the hardly soluble salt. The structure of claim 10.

12. The sparingly soluble salt is calcium carbonate.

12. A structure according to claim 10 or 11.

13. a step of providing a sealant in at least one of a void and a surface of a structure, the sealant comprising at least one of a first compound containing a cation constituting a hardly soluble salt and a second compound containing an anion constituting the hardly soluble salt, and a hardly soluble substance different from the first compound and the second compound, which serves as a nucleus for precipitating the hardly soluble salt from at least one of the cation and the anion; A method for constructing a structure comprising:

14. The hardly soluble substance is the hardly soluble salt.

14. A method for constructing a structure according to claim 13.

15. The sparingly soluble salt is calcium carbonate. A method for constructing a structure according to claim 13 or 14.

16. A repair method comprising applying the sealant according to any one of claims 1 to 9 to a repaired portion of a structure.

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