JP7814042B2 - Sealant, structure, method for constructing and repairing a structure - Google Patents

Description

This disclosure relates to a sealant for constructing a structure, a structure equipped with the sealant, and a method for constructing and repairing the structure.

Many structures are being constructed not only above ground, 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 are always present in underground bedrock, through which groundwater can well up, but the deeper the underground cavity being excavated, the more difficult it becomes to avoid sudden wellups due to increased pore water pressure. Therefore, to safely utilize underground environments and cavities over the long term, it is essential to have technology that can stop groundwater from leaking for long periods 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.

Japanese Patent Application Publication No. 4-1365

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

However, it has not been fully verified whether the watertightness achieved by these conventional technologies or the durability of existing structures can be maintained over 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.

The present disclosure has been made in light of these issues, and its purpose is to provide technology for improving at least one of the strength and durability of structures.

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.

Another aspect of the present disclosure is a structure. The structure includes a structure and a sealant present in at least one of the voids and the surface of the structure. The sealant includes a hardly soluble core and a hardly soluble salt present in the vicinity of the core.

Yet another aspect of the present disclosure is a method for constructing a structure. This method includes applying a sealant to 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 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 anion.

Yet another aspect of the present disclosure is a repair method. This method involves applying the above-described sealant to a repaired portion of a structure.

This disclosure makes it possible to improve at least one of the strength and durability of a structure.

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

This disclosure describes a technology that seals voids such as cracks in structures to improve their strength, corrosion resistance, and durability.

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.

When the sealant is kneaded with water or other liquids as needed 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 the sparingly soluble salt will elute from the first compound, and if the sealant contains a second compound, anions that form the sparingly soluble salt will elute from the second compound. If the sealant contains both the first and second compounds, sparingly soluble salt will be generated from the eluted cations and anions. If the sealant contains the first compound, sparingly soluble salt will be generated from the eluted cations and anions contained in the surrounding groundwater, etc. If the sealant contains the second compound, sparingly soluble salt will be generated from the eluted anions and cations contained in the surrounding groundwater, etc. In this process, the sparingly soluble substance contained in the sealant functions as a crystal nucleus, and the sparingly soluble salt will precipitate around the sparingly soluble substance. This promotes the precipitation of sparingly soluble salts, allowing the sparingly soluble salts to precipitate on-site and efficiently block the voids and surfaces before the eluted cations and anions diffuse from the voids and surfaces of the structure to the surrounding area. This improves the strength, corrosion resistance, and durability of the structure.

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.

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 pressed into voids in a structure, etc., and that hardens after being pressed in by a chemical reaction such as hydration or polymerization, or by heating, cooling, drying, or exposure to light. The base material may be, for example, cement, mortar, concrete, a thermosetting resin such as epoxy resin, a thermoplastic resin such as acrylic resin, or a mixture thereof. The sealant, in its solidified form, may be inserted into voids in a structure, etc.

The sparingly 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 sparingly soluble salts include 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), 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 may be lower than the solubility of the compound that is the main component of the base material. The poorly soluble salt may be appropriately selected depending on the environment in which the sealant is 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 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.

When calcium carbonate is precipitated as a sparingly soluble salt, the first compound may be any compound that can generate calcium ions, has sufficiently high solubility in water at the temperature of the environment in which the sealant is installed, and does not pollute the surrounding natural environment. Examples of the first compound include calcium chloride (CaCl ₂ ), calcium nitrate (Ca(NO ₃ ) ₂ ), and calcium bicarbonate (Ca(HCO ₃ ) ₂ ).

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 installed, and not polluting the surrounding natural environment. The second compound may be, for example, sodium bicarbonate (NaHCO ₃ ), potassium bicarbonate (KHCO ₃ ), ammonium bicarbonate (NH ₄ HCO ₃ ), etc.

The base material of the sealant may contain a sparingly soluble compound composed of the same cations or anions as those constituting 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 and concrete. This allows the calcium ions supplied from the first compound to shift the dissolution equilibrium of the sparingly soluble compound within the sealant toward the solid side, even if groundwater or rainwater penetrates into the interior of the sealant, such as concrete, thereby preventing calcium ions from leaching out of the base material. This prevents the calcium ions constituting the base material from gradually leaching out and being lost, which would otherwise cause microvoids and cracks within the base material and thereby reduce the strength of the sealant. This allows the strength of the sealant to be maintained over the long term, significantly improving the durability of structures.

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 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.

The hardly soluble material may be a powder. The particle size of the hardly 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 hardly 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 material may be measured by methods such as dynamic light scattering, laser diffraction/scattering, image imaging, and gravitational sedimentation.

The amount of the difficultly 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 difficultly 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.

The first compound and the second compound may be contained in the sealant as powders to facilitate elution of ions from the first compound and the second compound when the sealant is applied to a structure.

The sealant may include an ion exchange resin to which at least one of the cations and anions that make up the sparingly soluble salt has been 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 chemicals dissolved in the groundwater surrounding the sealant.

At least one of the cations and anions that make up the sparingly soluble salt may be encapsulated in a capsule and contained in the sealing material. The ions encapsulated in the capsule may be contained as at least one of a first compound and a second compound, or 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 ions in an appropriate amount and 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.

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

The base material, the first compound, the second compound, and the difficult-to-dissolve substance may be mixed on-site immediately before applying the mixture to the voids 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 difficult-to-dissolve 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 difficult-to-dissolve 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 difficult-to-dissolve substance may be premixed or mixed on-site. In this case, a difficult-to-dissolve 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 difficult-to-dissolve 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, etc.

Figure 2 shows a schematic cross-section of an example structure according to an embodiment. Structure 5 shown in Figure 2 is a structure that forms 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. Structure 5 includes a structural element 6 that forms the structure of structure 5, and a sealant 1 present in at least one of the voids and surface of structure 6. Structure 6 may be composed of, for example, cement, mortar, concrete, etc. Sealant 1 is disposed in the voids or surface of structure 6. Note that the structure according to the embodiment may be a building such as a house, building, or facility; a structure such as a tunnel, dam, or embankment; or any building, structure, or construction installed on the ground, underground, underwater, or at the bottom of the sea.

Figure 3 shows a schematic cross-section of a sealant according to an embodiment. Figure 3(a) shows a schematic cross-section of sealant 1 immediately after mixing base material 2, first compound 7, second compound 8, and poorly soluble substance 3. Figure 3(b) shows a schematic cross-section of sealant 1 after cations have been eluted from first compound 7 and anions have been eluted from second compound 8. Poorly soluble salt 4 precipitates from the cations generated from first compound 7, the anions generated from second compound 8, and counterions contained in the surrounding groundwater. Although poorly soluble salt 4 precipitates even in the absence of poorly soluble substance 3, crystal growth using poorly soluble substance 3 as a nucleus promotes the precipitation of poorly soluble salt 4. In some cases, poorly soluble salt 4 forms in contact with poorly soluble substance 3. In other cases, base material 2 adheres to the poorly soluble substance 3, and 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 by differences in crystallinity or crystal orientation, etc.

The above explanation describes a technology for sealing voids and surfaces in 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.

FIG. 4 is a flowchart showing the steps of a repair method according to an embodiment. First, the base material of the sealant, the first compound, the second compound, and the poorly soluble substance are mixed (S22). Next, the mixture is injected, inserted, applied, and/or sprayed into the repair area of the 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 poorly soluble substance may be mixed in advance or on-site. In this case, poorly soluble salts are 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 poorly soluble substance may be mixed in advance or on-site. In this case, poorly soluble salts are generated from cations eluted from the first compound and anions contained in the surrounding groundwater, etc.

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

[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: _CaCl2 (2.498 g) Agar (2.517 g)
Example 2: _CaCl2 (2.508 g) Agar (2.520 g)
Example 3: _CaCl2 (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 the presence 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 as a hardly soluble substance to serve as crystal nuclei to Examples 2 and 3. This agar solution was transferred to a molding cup and allowed to cool and solidify.

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 grain size cumulative frequency curve, 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.

[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.

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

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

The particle size of the precipitated calcium carbonate in Example 1, which did not contain calcium carbonate 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 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 limestone standard sample, was approximately 2 to 4 μm. The greater the amount of refractory material that served as crystal nuclei, the smaller the size of the calcium carbonate crystals produced and the greater the amount of particle growth. The greater the amount of refractory material that served as crystal nuclei, the more densely the particles grew, and the harder the sample was when cut with a knife.

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.

The present disclosure has been described above based on examples. These examples are merely illustrative, and those skilled in the art will understand that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present disclosure.

In the embodiment, a sparingly soluble salt is precipitated around the sparingly soluble material, but sparingly soluble compounds other than salt may also be precipitated. In this case, the sealant may contain a compound that is readily soluble in water but reacts chemically with other compounds present in the environment in which the sealant is placed to produce a sparingly soluble precipitate. For example, a compound that generates zinc ions may be contained in a sealant used to construct a structure underground near a volcano, causing zinc sulfide to precipitate by reacting with hydrogen sulfide present in the surrounding area.

An overview of one aspect of this disclosure is as follows:

A sealant according to one aspect 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. 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.

Both the first compound and the second compound may be present in the sealant. This 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.

Both the first compound and the second compound may be present separately in the sealant. This 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.

The sealant may further comprise a base material containing at least one of the first compound and the second compound and a sparingly soluble salt. This allows for efficient sealing of cracks in the structure, improving the strength, corrosion resistance, and durability of the structure.

The hardly soluble substance may be a hardly soluble salt. This promotes 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.

The sparingly 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. This can improve the strength, corrosion resistance, and durability of the structure.

The hardly soluble material may be in powder form. This promotes 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.

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

A structure according to one aspect of the present disclosure comprises a structure and a sealant present in at least one of the voids and surfaces of the structure, the sealant comprising a hardly soluble core and a hardly soluble salt present at least in contact with the core and in the vicinity of the core. This can improve the strength, corrosion resistance, and durability of the structure.

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

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

A method for constructing a structure according to one aspect of the present disclosure includes applying a sealant to at least one of the voids and surfaces of a structure, the sealant comprising at least one of a first compound containing a cation that constitutes a sparingly soluble salt and a second compound containing an anion that constitutes a sparingly soluble salt, and a sparingly soluble substance that serves as a nucleus for precipitating the sparingly soluble salt from at least one of the cation and anion. This 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.

The hardly soluble substance may be a hardly soluble salt. This promotes 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.

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

A repair method according to one aspect of the present disclosure involves applying any of the above-described sealants to the area of a structure to be repaired. This allows cracks and other imperfections in the structure to be efficiently sealed and repaired, improving the strength, corrosion resistance, and durability of the structure.

1. Sealant, 2. Base material, 3. Difficultly soluble substance, 4. Difficultly soluble salt, 5. Structure, 6. Structure, 7. First compound, 8. Second compound.

Claims (16)

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 a sealing material different from the first compound and the second compound. The sealant according to claim 1 , wherein 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 sparingly soluble salt. The sealant according to claim 1 or 2, wherein the first compound and the second compound have higher solubility in water than the hardly soluble compound at a temperature in an environment in which the sealant is disposed. The sealant according to claim 1 , further comprising a base material that encapsulates at least one of the first compound and the second compound and the poorly soluble salt. The sealant according to claim 1 , wherein the hardly soluble substance is the hardly soluble salt. the poorly soluble salt is calcium carbonate,
the first compound is at least one of calcium chloride, calcium nitrate, and calcium bicarbonate;
The sealant according to claim 1 , wherein the second compound is at least one of sodium bicarbonate, potassium bicarbonate, and ammonium bicarbonate. The sealant according to claim 1 , wherein the hardly soluble substance is a powder. The sealant according to claim 7, wherein the hardly soluble material has a particle size of 40 μm or less. The sealant according to claim 1 , further comprising an ion exchange resin to which at least one of the cations and the anions is adsorbed. 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: The structure according to claim 10 , wherein the hardly soluble substance is the hardly soluble salt. 12. The structure according to claim 10, wherein the hardly soluble salt is calcium carbonate. A method for constructing a structure, comprising the step of applying a sealant to 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 that constitutes a poorly soluble salt and a second compound containing an anion that constitutes the poorly soluble salt, and a poorly soluble substance different from the first compound and the second compound that serves as a nucleus for precipitating the poorly soluble salt from at least one of the cation and the anion. 14. The method for constructing a structure according to claim 13, wherein the hardly soluble substance is the hardly soluble salt. 15. The method for constructing a structure according to claim 13 or 14, wherein the sparingly soluble salt is calcium carbonate. A repair method in which the sealant described in any one of claims 1 to 9 is applied to the repaired area of a structure.