JP2017186182A - Filler for concrete structure, concrete structure and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filler for concrete structure excellent in workability, having fire retardancy and excellent in various physical properties such as wet surface adhesiveness and stretch/contraction followability, a concrete structure of which gaps is filled by the filler and a manufacturing method for obtaining them simply.SOLUTION: There is used a filler for concrete structure containing polymer hydrogel (A) having a three-dimensional network formed from a polymer of a water-soluble organic monomer and a water expansive clay mineral.SELECTED DRAWING: None

Description

  The present invention relates to a filler for a concrete structure excellent in various physical properties such as wet surface adhesion, a concrete structure, and a method for producing the same.

  Conventionally, various fillers have been proposed for concrete structure joints and cracks. However, there is a problem that adhesion itself is difficult on a complicated shape portion or a wet surface, and it cannot follow expansion and contraction due to seasonal fluctuations of the structure, resulting in peeling and brittle fracture.

  In response to these problems, a water-stopping material that has been molded by blending bentonite, thermoplastic resin, plasticizer, and water-absorbing resin as main raw materials has been proposed as an inexpensive water-stopping material that maintains a water-stop function for a long period of time. (For example, refer to Patent Document 1). However, since this water-stopping material has insufficient adhesion on the wet surface, there are problems that require an adhesive and are unsuitable for use in complex shapes.

  Therefore, there has been a demand for a filler that is excellent in workability and can exhibit excellent adhesion even in complex shapes and wet surfaces.

JP 2006-57275 A

  The problem to be solved by the present invention is a filler for a concrete structure that is excellent in workability, flame retardant, and excellent in various physical properties such as wet surface adhesion and stretchability, and the gap is filled with the filler. It is to provide a concrete structure and a manufacturing method thereof.

  The present inventors have found that a filler for a concrete structure containing a specific polymer hydrogel is excellent in workability, flame retardant, and excellent in various physical properties such as wet surface adhesion and stretchability. The present invention has been completed.

  That is, the present invention provides a filler for a concrete structure comprising a polymer hydrogel (A) having a three-dimensional network structure formed from a polymer of a water-soluble organic monomer and a water-swellable clay mineral. It is to provide.

  The filler for a concrete structure of the present invention is excellent in workability, flame retardant, and excellent in various physical properties such as adhesion to a concrete wet surface, stretchable followability, tunnel, road, bridge, track, It can be used as a filler for concrete structures such as buildings, revetments, water supply and sewerage, and as a repair material for them.

  The filler for a concrete structure of the present invention contains a polymer hydrogel (A) having a three-dimensional network structure formed of a polymer of a water-soluble organic monomer and a water-swellable clay mineral.

  As the method for producing the polymer hydrogel (A), a polymer hydrogel having a three-dimensional network structure can be easily obtained, so that a water-soluble organic monomer, a water-swellable clay mineral, a polymerization initiator, water, A method of polymerizing a water-soluble organic monomer in the dispersion liquid (a) containing The obtained polymer of water-soluble organic monomer forms a three-dimensional network structure together with the water-swellable clay mineral and becomes a constituent element of the polymer hydrogel (A).

  The water-soluble organic monomer is not particularly limited, and examples thereof include a monomer having a (meth) acrylamide group, a monomer having a (meth) acryloyloxy group, and an acrylic monomer having a hydroxyl group.

  Examples of the monomer having a (meth) acrylamide group include acrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N-isopropylacrylamide, and N-cyclopropylacrylamide. N, N-dimethylaminopropylacrylamide, N, N-diethylaminopropylacrylamide, acryloylmorpholine, methacrylamide, N, N-dimethylmethacrylamide, N, N-diethylmethacrylamide, N-methylmethacrylamide, N-ethyl Methacrylamide, N-isopropylmethacrylamide, N-cyclopropylmethacrylamide, N, N-dimethylaminopropylmethacrylamide, N, N-diethylaminopropylene Methacrylamide, and the like.

  Examples of the monomer having a (meth) acryloyloxy group include methoxyethyl acrylate, ethoxyethyl acrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, methoxymethyl acrylate, and ethoxymethyl acrylate.

  Examples of the acrylic monomer having a hydroxyl group include hydroxyethyl acrylate and hydroxyethyl methacrylate.

  Among these, from the viewpoint of solubility and physical properties of the resulting polymer hydrogel, it is preferable to use a monomer having a (meth) acrylamide group, and acrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N- Isopropyl acrylamide and acryloyl morpholine are more preferable, N, N-dimethyl acrylamide and acryloyl morpholine are more preferable, and N, N-dimethyl acrylamide is particularly preferable from the viewpoint of easy polymerization.

  The above water-soluble organic monomers may be used alone or in combination of two or more.

  The content of the water-soluble organic monomer in the dispersion (a) is preferably 1 to 50% by mass, and more preferably 5 to 30% by mass. When the content of the water-soluble organic monomer is 1% by mass or more, a hydrogel having excellent mechanical properties can be obtained. On the other hand, when the content of the water-soluble organic monomer is 50% by mass or less, it is preferable because the dispersion can be easily prepared.

  The water-swellable clay mineral forms a three-dimensional network structure with the polymer of the water-soluble organic monomer and becomes a constituent element of the polymer hydrogel.

  The water-swellable clay mineral is not particularly limited, and examples thereof include water-swellable smectite and water-swellable mica.

  Examples of the water-swellable smectite include water-swellable hectorite, water-swellable montmorillonite, and water-swellable saponite.

  Examples of the water-swellable mica include water-swellable synthetic mica.

  Among these, from the viewpoint of the stability of the dispersion, water-swellable hectorite and water-swellable montmorillonite are preferably used, and water-swellable hectorite is more preferably used.

  As the water-swellable clay mineral, naturally-derived, synthesized, and surface-modified ones can be used. Examples of the water-swellable clay mineral whose surface is modified include pyrophosphoric acid-added synthetic hectorite, fluorine-modified synthetic hectorite, and the like.

  In addition, the above-mentioned water-swellable clay mineral may be used alone or in combination of two or more.

  The content of the water-swellable clay mineral in the dispersion (a) is preferably 1 to 20% by mass, and more preferably 2 to 10% by mass. When the content of the water-swellable clay mineral is 1% by mass or more, a hydrogel having excellent mechanical properties can be synthesized. On the other hand, it is preferable that the content of the water-swellable clay mineral is 20% by mass or less because the dispersion can be easily prepared.

  The polymerization initiator is not particularly limited, and examples thereof include water-soluble peroxides and water-soluble azo compounds.

  Examples of the water-soluble peroxide include potassium peroxodisulfate, ammonium peroxodisulfate, sodium peroxodisulfate, and t-butyl hydroperoxide.

  Examples of the water-soluble azo compound include 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 4,4'-azobis (4-cyanovaleric acid), and the like.

  Among these, from the viewpoint of interaction with the water-swellable clay mineral, it is preferable to use a water-soluble peroxide, more preferably potassium peroxodisulfate, ammonium peroxodisulfate, or sodium peroxodisulfate, More preferably, potassium disulfate and ammonium peroxodisulfate are used.

  In addition, the above-mentioned polymerization initiator may be used independently or may be used in combination of 2 or more type.

  The molar ratio of the polymerization initiator to the water-soluble organic monomer in the dispersion (a) (polymerization initiator / water-soluble organic monomer) is preferably 0.01 or more, more preferably 0.02 to 0. .1 and more preferably 0.04 to 0.1.

  The content of the polymerization initiator in the dispersion (a) is preferably 0.1 to 10% by mass, and more preferably 0.2 to 10% by mass. It is preferable that the content of the polymerization initiator is 0.1% by mass or more because the organic monomer can be polymerized even in an air atmosphere. On the other hand, when the content of the polymerization initiator is 10% by mass or less, the dispersion can be used without agglomeration before polymerization, which is preferable because handling properties are improved.

  The dispersion (a) contains a water-soluble organic monomer, a water-swellable clay mineral, a polymerization initiator, and water, and if necessary, an organic solvent, a catalyst, an organic crosslinking agent, a preservative, and a thickener. Etc. may be further included.

  Examples of the organic solvent include alcohol compounds such as methanol, ethanol, propanol, isopropyl alcohol, and 1-butanol; ether compounds such as ethyl ether and ethylene glycol monoethyl ether; amide compounds such as dimethylformamide and N-methylpyrrolidone; acetone, Examples thereof include ketone compounds such as methyl ethyl ketone.

  Among these, from the viewpoint of the dispersibility of the water-swellable clay mineral, it is preferable to use an alcohol compound, more preferably methanol, ethanol, n-propyl alcohol, or isopropyl alcohol, and even more preferably methanol or ethanol. preferable.

  In addition, these organic solvents may be used independently or may be used in combination of 2 or more type.

  The catalyst has a function of increasing the polymerization rate when the water-soluble organic monomer is polymerized.

  Although it does not restrict | limit especially as said catalyst, A tertiary amine compound, thiosulfate, ascorbic acid, etc. are mentioned.

  Examples of the tertiary amine compound include N, N, N ′, N′-tetramethylethylenediamine, 3-dimethylaminopropionitrile and the like.

  Examples of the thiosulfate include sodium thiosulfate and ammonium thiosulfate.

  Examples of the ascorbic acids include L-ascorbic acid and sodium L-ascorbate.

  Among these, from the viewpoint of the stability of the dispersion, a tertiary amine compound is preferably used, and N, N, N ′, N′-tetramethylethylenediamine is more preferably used.

  In addition, the above-mentioned catalyst may be used independently or may be used in combination of 2 or more type.

  In the case of using a catalyst, the content of the catalyst in the dispersion (a) is preferably 0.01 to 1% by mass, and more preferably 0.05 to 0.5% by mass. The catalyst content of 0.01% by mass or more is preferable because the synthesis of the organic monomer of the resulting hydrogel can be efficiently promoted. On the other hand, the catalyst content of 1% by mass or less is preferable because the dispersion can be used without agglomeration before polymerization, and handling properties are improved.

  As a method for preparing the dispersion (a), for example, a method in which a water-soluble organic monomer, a water-swellable clay mineral, a polymerization initiator, water and the like are mixed together; a dispersion (a1) containing a water-soluble organic monomer And a solution containing the polymerization initiator (a2) as a separate dispersion or solution, and a multi-liquid mixing method in which the solution is mixed immediately before use are included. From the viewpoint of dispersibility, storage stability, viscosity control, etc. Therefore, a multi-liquid mixing method is preferable.

  Examples of the dispersion (a1) containing the water-soluble organic monomer include a dispersion obtained by mixing a water-soluble organic monomer and a water-swellable clay mineral.

  As a solution (a2) containing the said polymerization initiator, the aqueous solution etc. which mixed the polymerization initiator and water are mentioned, for example.

  The polymer hydrogel can be obtained by polymerizing a water-soluble organic monomer in the dispersion (a), but the polymerization method is not particularly limited and can be performed by a known method. Specific examples include radical polymerization by heating or ultraviolet irradiation, radical polymerization using a redox reaction, and the like.

  As superposition | polymerization temperature, it is preferable that it is 10-80 degreeC, and it is more preferable that it is 20-80 degreeC. A polymerization temperature of 10 ° C. or higher is preferred because radical reactions can proceed in a chain manner. On the other hand, when the polymerization temperature is 80 ° C. or less, it is preferable because water contained in the dispersion can be polymerized without boiling.

  The polymerization time varies depending on the kind of the polymerization initiator and the catalyst, but is carried out for several tens of seconds to 24 hours. In particular, in the case of radical polymerization utilizing heating or redox, it is preferably 1 to 24 hours, more preferably 5 to 24 hours. A polymerization time of 1 hour or longer is preferable because a polymer of a water-swellable clay mineral and a water-soluble organic monomer can form a three-dimensional network. On the other hand, since the polymerization reaction is almost completed within 24 hours, the polymerization time is preferably 24 hours or less.

  As a method for producing a filler for a concrete structure according to the present invention, it is possible to easily fill a complicated shape portion and the like, and the workability at a civil engineering construction site or a building construction site is further improved. A method in which the liquid (a) is injected into the gaps in the concrete structure and the polymer hydrogel (A) is produced in the gaps is preferred.

  The filler for a concrete structure of the present invention enters and adheres to a porous layer by a capillary phenomenon due to its affinity with concrete. Further, on the wet surface, it is considered that the porous surface enters and adheres so as to level the concentration gradient due to its high water absorption.

  The filler for a concrete structure of the present invention is excellent in workability, flame retardant, and excellent in various physical properties such as adhesion to a concrete wet surface, stretchable followability, tunnel, road, bridge, track, It can be used as a filler for concrete structures such as buildings, revetments, water supply and sewerage, and as a repair material for them.

  Hereinafter, the present invention will be described in more detail with reference to specific examples.

(Example 1: Production and evaluation of filler for concrete structure (1))
In 100 g of pure water, 10 g of N, N-dimethylacrylamide (manufactured by KJ Chemicals Co., Ltd.) and 1.6 g of water-swellable synthetic hectorite (manufactured by Big Chemie Japan Co., Ltd., “Laponite XLG”) are mixed and stirred. (A1-1) was prepared. Further, 5 g of potassium peroxodisulfate (hereinafter abbreviated as “KPS”) was mixed and stirred in 100 g of pure water to prepare an aqueous KPS solution (a2-1).
Next, the dispersion liquid (a1-1) and the KPS aqueous solution (a2-1) were mixed so that the mass ratio [(a1-1) / (a1-2)] was 10, and the dispersion liquid (a-1) Got.

[Evaluation of wet surface adhesion]
After immersing 60 × 300 × 300 mm of concrete flat plate (JIS A 5371) in water for 24 hours and wiping off only the water droplets on the surface, 3 kg / m ^{2 of} the dispersion (a-1) obtained above was applied, After curing for one week in an environment of 23 ° C. and 50% humidity to obtain a concrete structure filler (1), the concrete structure filler (1) is cut to a width of 25 mm in the direction of 180 °. The wet surface adhesion was evaluated according to the following criteria depending on the state of the filler when the filler was pulled.
○: Cohesive failure or substrate failure ×: Delamination

[Evaluation of stretchability]
Using the dispersion liquid (a-1) obtained above, the joint width was expanded / reduced in “Durability Test” of 5.17 of JIS A 1439. The deformation rate was ± 20%, the number of repetitions was 3,650 times, peeling / breaking was confirmed, and the stretchability of the filler for concrete structures (1) was evaluated according to the following criteria.
○: No peeling / breaking ×: Peeling or breaking

[Evaluation of flame retardancy]
The dispersion (a-1) obtained above was poured into a 1 mm thick container and polymerized at 20 ° C. to obtain a 1 mm thick sheet-like filler for concrete structures (1). This concrete structure filler (1) was subjected to an indirect flame for 30 seconds in accordance with the UL standard UL94HB class test method and evaluated according to the following criteria.
○: Not burned ×: Burned

(Example 2: Production and evaluation of filler for concrete structure (2))
In 100 g of pure water, 10 g of N, N-dimethylacrylamide (manufactured by KJ Chemicals Co., Ltd.) and 4 g of water-swellable synthetic hectorite (manufactured by Big Chemie Japan Co., Ltd., “Laponite XLG”) are mixed and stirred to obtain a dispersion (a1 -2) was prepared. Further, 5 g of potassium peroxodisulfate (KPS) was mixed and stirred in 100 g of pure water to prepare a KPS aqueous solution ((a2-2)).
Subsequently, the dispersion liquid (a1-2) and the KPS aqueous solution (a2-2) are mixed so that the mass ratio [(a1-2) / (a2-2)] is 10 to obtain the dispersion liquid (2). It was.

  A concrete structure filler (2) is produced in the same manner as in Example 1 except that the dispersion (a-1) used in Example 1 is changed to the dispersion (a-2), and each evaluation is performed. It was.

(Comparative Example 1)
Each evaluation was performed in the same manner as in Example 1 except that the dispersion liquid (a-1) used in Example 1 was changed to a two-component silicone sealant (“PM700LMG” manufactured by Cemedine Co., Ltd.) that satisfies JIS A5758. Went.

(Comparative Example 2)
Example 1 except that the dispersion liquid (a-1) used in Example 1 was changed to a water-reacting one-component foamed urethane (Japan TACCS Association “TACCS method for structural waterstop grade CR-020NF”). Each evaluation was performed in the same manner as above.

(Comparative Example 3)
Each evaluation was performed in the same manner as in Example 1 except that the dispersion liquid (a-1) used in Example 1 was changed to an epoxy resin satisfying JIS A6024 (“Bond E206” manufactured by Konishi Co., Ltd.).

  Each evaluation result obtained above is shown in Table 1.

  It was confirmed that the fillers for concrete structures of Examples 1 and 2 of the present invention are excellent in wet surface adhesion, stretchability and flame retardancy.

  On the other hand, Comparative Example 1 is an example in which a two-component silicone sealant was used as a filler, but it was confirmed that the wet surface adhesion was insufficient and the flame retardancy was poor.

  Although the comparative example 2 is an example which uses the water-reaction type one-component foaming urethane as a filler, it was confirmed that the stretchable followability is insufficient and the flame retardancy is inferior.

  Although the comparative example 3 is an example which uses an epoxy resin as a filler, it was confirmed that expansion / contraction followability is inadequate and incombustibility is inferior.

As a method for producing a filler for a concrete structure according to the present invention, it is possible to easily fill a complicated shape portion and the like, and the workability at a civil engineering construction site or a building construction site is further improved. liquid (a) is injected into the space of the concrete structure, a method of producing the polymer hydrogel (a) in the gap is preferred.

Claims (5)

  A filler for a concrete structure comprising a polymer hydrogel (A) having a three-dimensional network structure formed of a polymer of a water-soluble organic monomer and a water-swellable clay mineral.   The filler for a concrete structure according to claim 1, wherein the polymer hydrogel (A) comprises a water-soluble organic monomer, a water-swellable clay mineral, a polymerization initiator, and water as essential raw materials.   A concrete structure having a gap filled with the concrete structure filler according to claim 1.   The method for producing a filler for a concrete structure according to claim 1 or 2, wherein the polymer hydrogel (A) is generated in a gap between the concrete structures.   A method for producing a concrete structure, wherein the gap is filled with a filler obtained by the production method according to claim 4.