Repair material, repair mortar composition and hardened body

Abstract

To provide a repair material with improved compressive strength and wear resistance, the repair material having high fluidity and capable of enhancing self-healing properties, and to provide a repair composition and a cured product.SOLUTION: A repair material is formed of: a repair mixture containing one or more non-aqueous curing compounds selected from the group consisting of γ-2CaO_SiO2, 3CaO_2SiO2, α-CaO_SiO2, and calcium magnesium silicate; a cement; a polymer emulsion; a fiber; and a fine aggregate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a repair material, a repair mortar composition, and a hardened product thereof. [Background technology]

[0002] Concrete structures deteriorate due to salt damage, neutralization, freezing and thawing, chemical corrosion, etc., and there is a risk of cracks or loosening on the surface. As a countermeasure, deteriorated areas are identified by hammering tests, etc., and then removed using electric picks, air picks, water jets, etc., and repair work is carried out to fill in the gaps with new repair materials. In small-scale repair work where the cross section to be repaired is small, polymer cement mortar is often mixed and applied with a trowel to repair the cross section (see, for example, Patent Documents 1 and 2).

[0003] When repairing with a trowel or the like, a material with good workability, such as rapid hardening, ease of mixing, and ability to be applied thickly, is required. For this reason, in order to impart appropriate viscosity and sagging resistance to the mortar, materials containing inorganic fine powders such as fly ash and silica fume, as described in Patent Documents 1 and 2, and materials containing cellulose ethers, as described in Non-Patent Document 1 and Patent Documents 3 to 6, are used. Cellulose ethers increase viscosity and improve water retention, but they also have the problem of cracks occurring even after repair, necessitating re-repair.

[0004] Furthermore, Patent Document 7 proposes fibers and the like that promote the self-healing of cracks in hardened cement bodies through their self-healing effect even if cracks occur in the hardened cement body. However, when mixed with such fibers, there are problems such as a decrease in fluidity, poor workability, and the self-healing effect taking a long time.

[0005] Furthermore, conventional repair materials have low fluidity, which causes cracks to form in the hardened material. Furthermore, even after cracks occur, they have a low self-healing effect, resulting in low long-term strength and wear resistance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-322858 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-89565 [Patent Document 3] Japanese Patent Application Publication No. 11-349364 [Patent Document 4] Japanese Patent Application Laid-Open No. 2000-103662 [Patent Document 5] Japanese Patent Application Laid-Open No. 2000-128617 [Patent Document 6] Japanese Patent Application Publication No. 06-219807 [Patent Document 7] Japanese Patent Application Publication No. 2017-222555 [Non-patent literature]

[0007] [Non-Patent Document 1] Edited by Shinji Nagatomo: New Applications and Markets of Water-Soluble Polymers, CMC Publishing, pp.173-192, 1988 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, an object of the present invention is to provide a repair material, a repair mortar composition, and a hardened body that have high fluidity, can further enhance the self-healing effect, become dense through natural carbonation, and have improved compressive strength and abrasion resistance. [Means for solving the problem]

[0009] The present invention has been made to solve the above-mentioned problems, and as a result of various efforts made by the inventors to solve the above-mentioned problems, they discovered that by adding a repair material admixture containing a specific non-hydraulic material, it is possible to further increase compressive strength and abrasion resistance, and improve durability, and have thereby completed the present invention. The gist of the present invention is as follows. [1] A grout admixture containing one or more non-hydraulic compounds selected from the group consisting of γ-2CaO·SiO2, 3CaO·2SiO2, α-CaO·SiO2, and calcium magnesium silicate, and a repair material consisting of cement, polymer emulsion, fiber, and fine aggregate. [2] The repair material according to [1], wherein the non-hydraulic compound contains Li, and the Li content in the non-hydraulic compound is 0.001 to 1.0 mass % in terms of oxide. [3] A repair material according to any one of [1] to [2], wherein the amount of SO3 in the repair material is 0.5 mass% or more and 10.0 mass% or less, and the amount of MgO is 0.1 mass% or more and 3.0 mass% or less. [4] The repair material according to any one of [1] to [3], further comprising an expanding material. [5] The repair material according to any one of [1] to [4], further comprising a hardening agent, wherein the hardening agent contains calcium aluminate, the calcium aluminate has a CaO / Al2O3 molar ratio of 1.0 or more and 3.0 or less, and the content of the calcium aluminate is 2 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the cement. [6] The repair material according to any one of [1] to [5], wherein the content of the fine aggregate is 40 parts by mass or more and 300 parts by mass or less per 100 parts by mass of the cement. [7] A repair mortar composition containing the repair material according to any one of [1] to [6] and water. [8] A hardened body obtained by using the repair mortar composition described in [7]. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a repair material, a repair mortar composition, and a hardened body that have high fluidity, can further enhance the self-healing effect, become dense through natural carbonation, and have improved compressive strength and abrasion resistance. BEST MODE FOR CARRYING OUT THE INVENTION

[0011] The present invention will be described in detail below. In this specification, parts and mass % are based on mass unless otherwise specified. The repair mortar composition as used herein is a general term for pastes containing no coarse aggregate and mortars containing fine aggregate.

[0012] The repair material of the present invention comprises a repair admixture containing one or more non-hydraulic compounds selected from the group consisting of γ-2CaO·SiO2, 3CaO·2SiO2, α-CaO·SiO2, and calcium magnesium silicate, as well as cement, a polymer emulsion, fibers, and fine aggregate.

[0013] [Repair admixture] <Non-hydraulic compounds> (γ-2CaO·SiO2) γ-2CaO SiO2 is known as a low-temperature phase of the compound 2CaO SiO2, and is completely different from the high-temperature phases α-2CaO SiO2, α'-2CaO SiO2, and β-2CaO SiO2. Although all of these are expressed as 2CaO SiO2, they have different crystal structures and densities.

[0014] (3CaO 2SiO2) 3CaO·2SiO2 is a mineral called rankinite, which is a pseudowollastonite containing CaO. It is a chemically stable mineral with no hydration activity, but has a strong effect in promoting carbonation.

[0015] (α-CaO SiO2) α-CaO·SiO2 (α-type wollastonite) is known as a high-temperature phase among the compounds expressed as CaO·SiO2, and is completely different from the low-temperature phase β-CaO·SiO2. Although both are expressed as CaO·SiO2, they have different crystal structures and densities.

[0016] Naturally occurring wollastonite is a low-temperature phase of β-CaO SiO2. β-CaO SiO2 has needle-like crystals and is used as an inorganic fibrous material such as wollastonite fiber, but it does not have the carbonation-promoting effect of the α-CaO SiO2 of this embodiment.

[0017] (Calcium Magnesium Silicate) Calcium magnesium silicate is a general term for CaO-MgO-SiO2 compounds, but in this embodiment, merwinite represented by 3CaO·MgO·2SiO2 (C3MS2) is preferred, as merwinite achieves a significant carbonation (salt) promotion effect.

[0018] The non-hydraulic compound may be one or more of the above, and the Li content in the non-hydraulic compound is 0.001 to 1.0%, preferably 0.005 to 1.0%, more preferably 0.010 to 0.90%, and even more preferably 0.015 to 0.80%, calculated as the oxide. When the Li content is 0.001% or more and 1.0% or less, calculated as the oxide, a carbonation-promoting effect is obtained. The Li content calculated as the oxide can be measured by the method described in the Examples. When two or more non-hydraulic compounds are used, the Li content refers to the Li oxide content relative to the total of the two or more non-hydraulic compounds.

[0019] Of the non-hydraulic compounds mentioned above, γ-2CaO·SiO2 is particularly preferred because it requires less energy to grind than other compounds due to the powdering phenomenon known as dusting that occurs during production, it has a significant effect of promoting carbonation over the long term, and when combined with blast furnace cement at a low water-binder ratio, it has a very significant effect of inhibiting carbonation.

[0020] The non-hydraulic compound according to this embodiment is obtained by blending a CaO source, a SiO2 source, a MgO source, and a Li source in a predetermined molar ratio and then heat-treating the blend. Examples of CaO sources include calcium carbonate (e.g., limestone), calcium hydroxide (e.g., slaked lime), by-product slaked lime (e.g., acetylene-based slaked lime), and fine powder generated from waste concrete. Examples of SiO2 sources include silica stone, clay, and various siliceous dusts generated as industrial by-products, such as silica fume and fly ash. Examples of MgO sources include magnesium hydroxide, basic magnesium carbonate, and dolomite. Examples of Li sources include lithium carbonate. Note that if the CaO source, SiO2 source, and MgO source contain Li, there is no need to add a Li source. To reduce non-energy-derived CO2 emissions during heat treatment, one or more selected from industrial by-products containing CaO, such as by-product slaked lime, fine powder generated from waste concrete blocks, municipal waste incineration ash, and sewage sludge incineration ash, can be used. Among these, the use of by-product slaked lime, which contains fewer impurities than other industrial by-products, is more preferable.

[0021] Examples of by-product slaked lime include by-product slaked lime produced during the acetylene gas production process using the calcium carbide method (wet and dry types are available depending on the acetylene gas production method), and by-product slaked lime contained in the dust captured during the wet dust collection process of a calcium carbide electric furnace. By-product slaked lime contains, for example, 65 to 95% (preferably 70 to 90%) calcium hydroxide, 1 to 10% calcium carbonate, and 0.1 to 6.0% (preferably 0.1 to 3.0%) iron oxide. These proportions can be confirmed by X-ray fluorescence analysis and differential thermogravimetric analysis (TG-DTA) based on the mass loss (Ca(OH)2: approximately 405 to 515°C, CaCO3: approximately 650 to 765°C). The volume-average particle size measured by laser diffraction / scattering is approximately 50 to 100 μm. Furthermore, the moisture content measured by the loss on drying method in JIS K 0068 "Method for measuring moisture content in chemical products" is preferably 10% or less. Also, sulfur compounds such as CaS, A12S3, and CaC2·CaS may be contained, but the content is preferably 2% or less.

[0022] The heat treatment at a high temperature of 1,000°C or higher as described above is not particularly limited, but can be carried out, for example, in a rotary kiln, an electric furnace, etc. The heat treatment temperature is not uniquely determined, but is usually carried out in the range of about 1,000 to 1,800°C, and often in the range of about 1,200 to 1,600°C.

[0023] In this embodiment, industrial by-products containing the aforementioned non-hydraulic compounds can also be used. In this case, impurities coexist. Examples of such industrial by-products include steel slag.

[0024] The CaO raw material, SiO2 raw material, and MgO raw material may contain impurities, but these do not pose any particular problems as long as they do not impair the effects of the present invention. Specific examples of impurities include Al2O3, Fe2O3, TiO2, MnO, Na2O, KO, S, PO5, F, BO3, and chlorine. Coexisting compounds include free calcium oxide, calcium hydroxide, calcium aluminate, calcium aluminosilicate, calcium ferrite, calcium aluminoferrite, calcium phosphate, calcium borate, magnesium silicate, leucite (KO, Na2O)·Al2O3·SiO2, spinel MgO·Al2O3, magnetite Fe3O4, and sulfur compounds such as CaS, Al2S3, and CaC2·CaS.

[0025] Of these impurities, the content of S (sulfur) in the non-hydraulic compound is preferably 1.0% or less, more preferably 0.7% or less, and even more preferably 0.5% or less, calculated as oxide (SO3). A content of 1.0% or less provides a sufficient carbonation (salt) promotion effect and also allows the setting and hardening properties to be within an appropriate range. The S content calculated as oxide (SO3) can be measured by X-ray fluorescence analysis. Note that S (sulfur) may be present in the non-hydraulic compound at a concentration of about 2% calculated as oxide.

[0026] In this repair admixture, the content of non-hydraulic compounds (the content of the total amount when multiple types are included) is preferably 65% ​​or more, more preferably 70% or more, and even more preferably 75% or more. Note that hydraulic 2CaO·SiO2 other than γ-2CaO·SiO2 can also be mixed in, up to a maximum of 35%.

[0027] The content of γ-2CaO SiO2 in this repair admixture is preferably 35% or more, more preferably 45% or more. There is no upper limit to the content of γ-2CaO SiO2. Among steelmaking slags, electric furnace reduction slag or stainless steel slag, which have a high content of γ-2CaO SiO2, is preferred.

[0028] As chemical components, it is more preferable that the cement admixture contains 0.002 to 0.5 parts of Li2O, 60 to 70 parts of CaO, 30 to 45 parts of SiO2, and 0.5 to 5 parts of Al2O3 per 100 parts of the cement admixture. Furthermore, as chemical components, the total amount of Li2O, CaO, SiO2, and Al2O3 is preferably 90 parts or more, and more preferably 95 to 100 parts, per 100 parts of the cement admixture.

[0029] The Rietveld method using powder X-ray diffraction may be used to quantify the non-hydraulic compounds in this repair admixture.

[0030] The Blaine specific surface area of ​​this grout admixture is not particularly limited, but is preferably 1,500 cm 2 / g or more is preferable, and the upper limit is 8,000 cm 2 / g or less is preferable. 2 / g is more preferable, and 4,000 to 6,000 cm 2 / g is most preferable. 2 / g or more, good resistance to material separation is obtained, and the carbonation (salt) promotion effect is sufficient. 2 / g or less, the grinding power required for grinding is not large, which is economical, and weathering can be suppressed, thereby preventing deterioration of quality over time.

[0031] [cement] The cement used in the present invention is not particularly limited, and examples include various cements such as normal, early-strength, ultra-early-strength, low-heat, and moderate-heat cements, various mixed cements obtained by mixing these cements with blast furnace slag, fly ash, or silica fume, environmentally friendly cements (ecocement) made from municipal waste incineration ash or sewage sludge incineration ash, and commercially available fine particle cements. It is also possible to use various cements and mixed cements that have been finely powdered. Furthermore, cements prepared by increasing or decreasing the amount of components (such as gypsum) normally used in cements can also be used. In the present invention, it is preferable to select ordinary Portland cement or high-early-strength Portland cement from the viewpoints of high fluidity, improved self-healing effect, increased compressive strength, and improved abrasion resistance.

[0032] The cement used in this invention has a Blaine specific surface area of ​​2,500 cm from the viewpoint of production cost and strength development. 2 / g or more 7,000cm 2 / g or less, and 2 / g or more 6,000cm 2 / g or less is more preferable, and 2 / g or more 4,500cm 2 It is more preferable that the saturation coefficient is 1 / g or less. The Blaine specific surface area value is determined in accordance with JIS R 5201 (physical testing method for cement).

[0033] [Polymer emulsion] The polymer emulsion used in the present invention is not particularly limited, but examples thereof include rubber latexes such as acrylonitrile-butadiene rubber, styrene-butadiene rubber, chloroprene rubber, and natural rubber; resin emulsions such as ethylene-vinyl acetate copolymers, polyacrylates, styrene-acrylate copolymers, and acrylic ester copolymers such as acrylonitrile-acrylate copolymers; and vinyl acetate-vinyl versatate copolymers. The polymer comes in a re-emulsifiable powder form or a liquid form, and is used to improve adhesion to the substrate and the durability of the mortar.

[0034] The content of the polymer emulsion is preferably 1 to 15 parts by mass, more preferably 2 to 12 parts by mass, and even more preferably 3 to 10 parts by mass, in terms of solid content, relative to 100 parts by mass of cement. By having the content of the polymer emulsion within the above range, it is possible to increase fluidity and improve the self-healing effect.

[0035] [fiber] The fibers used in the present invention improve buildability and crack resistance. The type of fiber is not particularly limited, but examples include polymer fibers such as vinylon fiber, propylene fiber, acrylic fiber, nylon fiber, and aramid fiber, and inorganic fibers such as steel fiber, glass fiber, carbon fiber, and fibers made by melt-spinning rocks such as basalt.

[0036] The fiber content is preferably 0.02 parts by mass or more and 1.5 parts by mass or less, more preferably 0.03 parts by mass or more and 1.2 parts by mass or less, and even more preferably 0.05 parts by mass or more and 1.0 parts by mass or less, relative to 100 parts by mass of cement. When the amount of fiber used is 0.02 parts by mass or more, the effect of improving sagging can be fully exerted. Furthermore, when the fiber content is 1.5 parts by mass or less, the fluidity can be increased and the self-healing effect can be improved. From the viewpoint of the aesthetic appearance of the trowel-finished surface, the fiber length is preferably 15 mm or less, more preferably 12 mm or less, and even more preferably 10 mm or less. There is no particular limitation on the lower limit of the fiber length, and it may be, for example, 1 mm or more.

[0037] [Fine aggregate] The chemical components of the fine aggregate used in the present invention preferably contain 85% or more by mass of CaO and 0.2% to 15% by mass of SiO2. When the CaO and SiO2 contents are within the above ranges, a repair material with high fluidity, carbonation resistance, and adhesion strength to reinforcing bars, as well as excellent rust prevention, can be obtained. The proportion of CaO is preferably 87% by mass or more, more preferably 89% by mass or more, and even more preferably 91% by mass or more. The upper limit of the proportion of CaO is not particularly limited, but is preferably 99% by mass or less, and more preferably 98.5% by mass or less. The proportion of SiO2 is preferably 0.25 mass % or more and 13 mass % or less, more preferably 0.3 mass % or more and 11 mass % or less, and even more preferably 0.4 mass % or more and 10 mass % or less. To ensure that the chemical composition of the fine aggregate falls within the above and below-mentioned ranges, silica sand, calcite, scapolite, a metamorphic rock, quartz, a igneous rock, potassium feldspar, and other rocks are mixed together to ensure that the chemical composition falls within the ranges specified in the present invention. The various rocks are mixed and adjusted while checking with X-ray fluorescence analysis. The chemical composition of the fine aggregate used in the present invention is calculated in terms of oxides.

[0038] The fine aggregate used in the present invention can be the same as that used in ordinary cement mortar or concrete. Specifically, river sand, crushed stone, crushed sand, lime sand, silica sand, colored sand, artificial lightweight aggregate, etc. can be used, and combinations of these are also possible. In particular, for applications where increased fluidity and self-healing effects are desired, the use of siliceous silica sand or lime sand is preferred, and the particle size of the fine aggregate is preferably JIS No. 6 to JIS No. 8.

[0039] The content of fine aggregate is preferably 40 to 300 parts by mass, more preferably 45 to 275 parts by mass, and even more preferably 50 to 250 parts by mass, per 100 parts by mass of cement. When the particle size of the fine aggregate is within the above range, sufficient fluidity, self-healing effect, improved abrasion resistance, and low shrinkage can be obtained.

[0040] [Li] The repair admixture can further contain Li in the non-hydraulic compound, and the content can be 0.001 to 1.0 mass% in terms of oxide. It is presumed that Li promotes the formation of vaterite, a type of calcium carbonate, during the carbonation of CSH (calcium silicate hydrate), and that carbonation results in a denser hardened state, which is likely to increase strength, improve abrasion resistance, and reduce shrinkage. Here, "Li contained in a non-hydraulic compound" refers to a state in which the non-hydraulic compound contains Li2O as a chemical composition (its presence can be confirmed by ICP atomic emission spectroscopy), but Li2O is not identified by X-ray diffraction measurement (no clear Li2O peak is observed), and does not simply refer to a state in which the non-hydraulic compound and the Li compound are physically mixed. This state can be achieved by mixing the respective raw materials and heat treating them at high temperatures of 1,000°C or higher. Each component will be explained below.

[0041] [SO3 and MgO] The amounts of SO3 and MgO contained in the repair material can be adjusted, for example, by adding an admixture containing SO3 and MgO when preparing the repair material. The amounts of SO3 and MgO can also be measured by X-ray fluorescence spectroscopy (XRF).

[0042] The amount of SO3 contained in the repair material in the present invention is preferably 0.5 mass% or more, more preferably 0.7 mass% or more, and even more preferably 0.8 mass% or more, from the viewpoint of increasing the fluidity of the repair material and improving the self-healing effect. Also, from the same viewpoint, the amount of SO3 contained in the repair material is required to be 10.0 mass% or less, preferably 8.0 mass% or less, and even more preferably 6.0 mass% or less.

[0043] The amount of MgO contained in the repair material is preferably 0.1 mass% or more, more preferably 0.15 mass% or more, and even more preferably 0.2 mass% or more, from the viewpoint of increasing the fluidity of the repair material and improving the self-healing effect. Also, from the same viewpoint, the amount of MgO contained in the repair material is preferably 3.0 mass% or less, more preferably 2.0 mass% or less, and even more preferably 1.0 mass% or less.

[0044] [Expansive material] The repair material of the present invention can further contain an expansive material. The expansive material used in the present invention is not particularly limited, and any material that generates expansive hydrates and suppresses bleeding can be used. Known expansive materials include free lime, free magnesia, calcium ferrite, ettringite, lime, and ettringite-lime composites, and are not particularly limited, but from the viewpoint of long-term stability, those containing free lime are preferred. Examples of those containing free lime include free lime-anhydrous gypsum systems, free lime-hydraulic compound systems, and free lime-hydraulic compound-anhydrous gypsum systems. Expansion agents and static crushing agents are commercially available from various companies, and representative examples include Denka CSA#20 and Denka Power CSA manufactured by Denka Co., Ltd., and Expan, Hyperexpan, N-EX, and Blaister manufactured by Pacific Materials Corporation, as well as crushed products of these.

[0045] The particle size of the expanding material used in the present invention is not particularly limited, but it is preferably 2,000 cm 2 or less in terms of Blaine specific surface area. 2 / g or more 25,000cm 2 / g or less is preferable, and 2 / g or more 15,000cm 2 / g or less is more preferable, and 2,400 cm 2 / g or more 10,000cm 2 / g or less is more preferable. When the Blaine specific surface area of ​​the expanding material is equal to or greater than the lower limit, bleeding can be suppressed. When the Blaine specific surface area of ​​the expanding material is equal to or less than the upper limit, sufficient expansion can be obtained.

[0046] The content of the expansive agent used in the present invention is preferably 0.5 to 20 parts by mass, more preferably 1.0 to 18 parts by mass, and even more preferably 2 to 15 parts by mass, relative to 100 parts by mass of cement. When the content of the expansive agent is equal to or greater than the lower limit, crack suppression effect is easily achieved. When the content of the expansive agent is equal to or less than the upper limit, strength development is good. When the content of the expansive agent is within the above range, it is easy to obtain a repair material that satisfies the effects of the present invention, i.e., a repair material that has increased fluidity, improved self-healing effect, and low shrinkage.

[0047] [Sudden hardwood] The repair material of the present invention comprises a repair admixture containing one or more non-hydraulic compounds selected from the group consisting of γ-2CaO·SiO2, 3CaO·2SiO2, α-CaO·SiO2, and calcium magnesium silicate, as well as cement, expansive material, polymer emulsion, fiber, and fine aggregate, and may contain a rapid hardening agent to promote setting and increase strength in a short period of time. The hardening accelerator used in the present invention is not particularly limited as long as it promotes setting and increases strength in a short period of time. Examples of hardening accelerators that promote setting include calcium salts of organic acids such as calcium formate, nitrates, sulfates, carbonates, thiocyanates, amines, maleic anhydride, silicates such as water glass, aluminum sulfate, and aluminum salts such as alum, calcium aluminate (calcium aluminate), and aluminates. Among these, aluminates are preferred from the viewpoint of strength development, and calcium aluminate (CA) is preferred. Calcium aluminate is more preferred from the viewpoint of improving strength development when used in combination with gypsum. The amount of gypsum used is preferably 80 to 250 parts by mass, more preferably 90 to 220 parts by mass, and even more preferably 100 to 200 parts by mass, per 100 parts by mass of calcium aluminate. Having a gypsum content equal to or greater than the above-mentioned lower limit facilitates rapid hardening. Furthermore, when the gypsum content is equal to or less than the upper limit, the strength development and self-healing effect are good. When the gypsum content is within the above range, it is easy to obtain a repair material that improves the self-healing effect and satisfies the effects of the present invention. Calcium aluminate is a general term for a hydration-active substance composed primarily of CaO and Al2O3, which is obtained by mixing calcia raw materials and alumina raw materials, firing them in a kiln, or melting them in an electric furnace and cooling them. Either crystalline or amorphous calcium aluminate can be used. It is a material with a fast setting time and high early strength development. Alumina cement is a typical example of calcium aluminate, and commercially available products are usually used. For example, Alumina Cement No. 1 and Alumina Cement No. 2 can be used. Among these, amorphous calcium aluminate, which is melted and then rapidly cooled, is preferred because it sets in a shorter time than alumina cement and subsequently develops high early strength. Among calcium aluminates, the molar ratio of CaO to Al2O3 (CaO / Al2O3 molar ratio) is preferably 1.0 or more and 3.0 or less, and more preferably 1.7 or more and 2.5 or less. By having the molar ratio within the above range, the curing time can be further shortened and the early strength development can be improved.

[0048] In the present invention, the impurity content in calcium aluminate is preferably 15% by mass or less, more preferably 10% by mass or less, from the viewpoint of early strength development. Here, impurities refer to substances other than CaO and Al2O3. If the impurity content exceeds 15% by mass, the hardening process may take a long time and may not solidify at low temperatures. Typical examples of impurities include silicon oxide, magnesium oxide, and sulfur oxide. Other examples include organic substances, alkali metal oxides, alkaline earth metal oxides, titanium oxide, iron oxide, alkali metal halides, alkaline earth metal halides, alkali metal sulfates, and alkaline earth metal sulfates partially substituted or dissolved in CaO or Al2O3. However, impurities are not limited to these.

[0049] The vitrification rate of calcium aluminate used in the present invention is preferably 70% by mass or more, more preferably 90% by mass or more, in terms of reaction activity. If the vitrification rate is less than 70% by mass, the initial strength development may decrease. The vitrification rate of calcium aluminate is preferably 70% by mass or more, more preferably 90% by mass or more, in terms of reaction activity. The vitrification rate is determined by measuring the main peak area S of the crystalline mineral of a measurement sample in advance by powder X-ray diffraction, then heating at 1,000°C for 2 hours, followed by slow cooling at a cooling rate of (1 to 10°C) / min, and determining the main peak area S0 of the crystalline mineral after heating by powder X-ray diffraction. Using these S0 and S values, the vitrification rate is calculated using the following formula: X Calculate. Vitrification rate X (mass%)=100×(1-S / S0) The particle size of calcium aluminate is such that it has a Blaine specific surface area of ​​3,000 cm in terms of early strength development. 2 / g or more is preferable, and 5,000 cm 2When the particle size of calcium aluminate is equal to or greater than the above lower limit, the hardening time is shortened, resulting in good early strength development and good self-healing performance.

[0050] The content of the hardening agent used in the present invention is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, per 100 parts by mass of cement. Furthermore, when calcium aluminate is used as the hardening agent, the content of calcium aluminate is preferably 2 to 20 parts by mass, more preferably 3 to 18 parts by mass, and even more preferably 4 to 15 parts by mass, per 100 parts by mass of cement. When the content of the hardening agent is equal to or greater than the lower limit, rapid hardening and crack suppression effects are easily achieved. Furthermore, when the content of the hardening agent is equal to or less than the upper limit, strength development is improved. When the content of the hardening agent is within the above range, it is easy to improve the self-healing effect, and a repair material that satisfies the effects of the present invention can be obtained.

[0051] [Water reducing agent] The water-reducing agent used in the present invention helps disperse each material and also plays a role in imparting fluidity to the mixed repair mortar.

[0052] The water-reducing agent used in the present invention is not particularly limited, and examples thereof include naphthalene-based water-reducing agents, melamine-based flow-through water-reducing agents, aminosulfonic acid-based water-reducing agents, and polycarboxylic acid-based water-reducing agents. One or more of these water-reducing agents can be used in the present invention. Specific examples of water-reducing agents include naphthalene-based water-reducing agents such as the "Leobuild SP-9 Series" manufactured by NMB Corporation, the "Mighty 2000 Series" manufactured by Kao Corporation, and the "Sunflow HS-100" manufactured by Nippon Paper Industries Co., Ltd.; melamine-based water-reducing agents such as the "Sikament 1000 Series" manufactured by Sika Japan and the "Sunflow HS-40" manufactured by Nippon Paper Industries Co., Ltd.; aminosulfonic acid-based water-reducing agents such as the "Paric FP-200 Series" manufactured by Fujisawa Pharmaceutical Co., Ltd.; and polycarboxylic acid-based water-reducing agents such as the "Leobuild SP-8 Series" manufactured by NMB Corporation, the "Darlex Super 100PHX" manufactured by Grace Chemicals, and the "Chupol HP-8 Series" and "Chupol HP-11 Series" manufactured by Takemoto Oil & Fat Co., Ltd. Powdered water-reducing agents are also available. Specific examples of naphthalene-based water-reducing agents include "Mighty 100" manufactured by Kao Corporation, "Sanyo Revellon P" manufactured by Sanyo Chemical Industries, Ltd., and "Celluflow 110P" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. Melamine-based water-reducing agents include "Melment F10M" manufactured by BASF Pozzolith, Ltd. Polycarboxylic acid-based water-reducing agents include "Queenflow 750" manufactured by Mitsubishi Chemical Corporation and "CAD9000P" manufactured by Kao Corporation.

[0053] The content of the water-reducing agent is preferably 0.1 to 2 parts by mass, more preferably 0.2 to 1.8 parts by mass, and even more preferably 0.3 to 1.0 parts by mass, in terms of solid content, per 100 parts by mass of cement. By having the content of the water-reducing agent be equal to or greater than the lower limit, sufficient fluidity can be obtained. Furthermore, by having the content of the water-reducing agent be equal to or less than the upper limit, material separation can be suppressed.

[0054] [Silica fine powder] The repair material of the present invention can contain, in addition to cement, expansive agent, polymer emulsion, fiber, and fine aggregate, silica fine powder in order to improve strength development, acid resistance, ensure usable time, and improve dimensional stability.

[0055] Examples of the siliceous fine powder include latent hydraulic substances such as ground granulated blast furnace slag, fly ash, and pozzolanic substances such as silica fume, with silica fume being preferred. There are no restrictions on the type of silica fume, but from the viewpoint of fluidity, it is preferable to use silica fume containing 10% or less of ZrO2 as an impurity or acidic silica fume. Acidic silica fume is defined as silica fume that, when 1 g of silica fume is added to 100 cc of pure water and stirred, the supernatant liquid has an acidic pH of 5.0 or less.

[0056] The fineness of the silica powder is not particularly limited, but usually, the fine powder of granulated blast furnace slag and fly ash has a Blaine value of 3,000 cm 2 / g or more 9,000cm 2 / g or less, and silica fume has a BET specific surface area of ​​20,000 cm 2 / g or more 300,000 cm 2 / g or less.

[0057] The content of the siliceous fine powder is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, and even more preferably 3 to 10 parts by mass, per 100 parts by mass of cement. Having the content of the siliceous fine powder equal to or greater than the lower limit mentioned above can improve strength development, acid resistance, ensure usable time, and dimensional stability. Having the content of the siliceous fine powder equal to or less than the upper limit mentioned above can improve fluidity and the self-healing effect.

[0058] [others] In the present invention, one or more of the following may be used to the extent that they do not adversely affect performance: setting regulators, air-entraining agents, rust inhibitors, water repellents, antibacterial agents, colorants, antifreeze agents, fine limestone powder, finely cooled blast furnace slag powder, admixtures such as sewage sludge incineration ash and its molten slag, municipal waste incineration ash and its molten slag, and pulp sludge incineration ash; antifoaming agents; thickeners; shrinkage reducing agents; clay minerals such as bentonite and sepiolite; and anion exchangers such as hydrotalcite.

[0059] In the repair material of the present invention, the method for mixing the materials is not particularly limited, and the materials may be mixed at the time of application, or some or all of the materials may be mixed in advance. As the mixing device, any existing device such as a tilting mixer, an omni mixer, a Henschel mixer, a V-type mixer, or a Nauta mixer can be used.

[0060] The repair mortar composition of the present invention contains the repair material of the present invention and water, and is prepared by kneading the repair material and water. The amount of mixing water in the present invention is not particularly limited, as it varies depending on the purpose and application of use and the content ratio of each material, but is preferably 10 to 70 parts by mass, more preferably 14 to 65 parts by mass, and even more preferably 16 to 60 parts by mass, per 100 parts by mass of repair material. By keeping the amount of mixing water at or above the above lower limit, it is possible to prevent a decrease in fluidity and prevent the heat generation from becoming extremely large. Furthermore, by keeping the amount of mixing water at or below the above upper limit, it is possible to ensure strength development.

[0061] In the present invention, the method for mixing the repair material and water is not particularly limited, but it is preferable to use a hand mixer with a rotation speed of 900 rpm or more, a normal mortar mixer, or a twin-screw forced mixer.

[0062] When mixing with a hand mixer or mortar mixer, it is preferable to first add a predetermined amount of water to a container such as a pail or mixer, then add the remaining repair mortar composition while rotating the mixer, and mix for at least 3 minutes. When mixing with a forced mixer, it is preferable to first add the repair mortar composition to the mixer, add the predetermined amount of water while rotating the mixer, and mix for at least 4 minutes. If the mixing time is shorter than the predetermined time, the repair mortar composition may not have the proper fluidity due to insufficient mixing. The mixed repair mortar composition is usually applied using a plastering trowel or pumped to the application site using a squeeze-type mortar pump, and then sprayed using compressed air with a spray nozzle to form a hardened body using the repair mortar composition of the present invention. [Example]

[0063] The present invention will be further explained below based on experimental examples of the present invention, but the present invention is not limited to these.

[0064] Experimental Example 1 A repair material was prepared by adding 11.1 parts by mass of expansive additive, 3.0 parts by mass of polymer emulsion, 0.1 parts by mass of fiber, and 0.5 parts by mass of water-reducing agent per 100 parts by mass of cement, and by adding the repair admixture, rapid hardening material, and fine aggregate in the amounts shown in Table 1 per 100 parts by mass of cement. Next, the SO3 content of the repair material was measured by X-ray fluorescence analysis, and the MgO content was also measured by X-ray fluorescence analysis. Taking these measurements into consideration, an SO3-containing admixture (material name: potassium sulfate) and an MgO-containing admixture (material name: magnesium carbonate) were mixed so that the final repair material would have the SO3 and MgO contents shown in Table 1 below, to prepare the repair material. 100 parts by mass of the resulting repair material was mixed with 15 parts by mass of water to prepare a repair mortar composition. The prepared repair mortar compositions were tested for fluidity, self-healing effect, compressive strength, and abrasion resistance. The results are shown in Table 1.

[0065] <Materials used> Cement: Ordinary Portland cement, Blaine value 3,450 cm 2 / g Expanding agent: CaO raw material, Al2O3 raw material, SiO2 raw material, and CaSO4 raw material are mixed and crushed, then fired at 1,200°C to synthesize clinker, which is then crushed in a ball mill to produce a clinker with a Blaine specific surface area of ​​3,000 cm 2 / g. Polymer emulsion: Polyacrylate ester re-emulsified resin, commercially available product, moisture content 0.8%, density 0.5g / mL Fiber: Vinylon fiber, fiber length 6mm, fineness 6.6dtex, dry strength 1,850N / mm 2 , dry elongation 6.0% Water reducing agent: Naphthalene-based water reducing agent, commercially available (Dai-ichi Kogyo Seiyaku Co., Ltd. "Cellflow 110P") Water: Tap water · Fine aggregate: lime sand, a mixture of 50% 0.6mm and under and 50% 0.6~1.2mm fine aggregate was used. Repair admixture A: Li-containing γ-2CaO·SiO2. First-grade reagent calcium carbonate and first-grade reagent silicon dioxide were mixed in a molar ratio of 2:1, and then first-grade reagent lithium carbonate was added so that the Li content of the mixture was 0.0005-1.1% (internal substitution) in terms of oxide (Li2O). The mixed sample was heat-treated at 1,400°C for 2 hours and allowed to cool to room temperature. The cooled sample was pulverized and crushed to obtain a Blaine specific surface area of ​​4,000 cm 2 / g. Repair admixture B: Li-containing α-CaO·SiO2. First-grade reagent calcium carbonate and first-grade reagent silicon dioxide were mixed in a 1:1 molar ratio, and then first-grade reagent lithium carbonate was added so that the Li content of the mixture was 0.0005-1.1% (internal substitution) in terms of oxide (Li2O). The mixed sample was heat-treated at 1,500°C for 2 hours and allowed to cool to room temperature. The cooled sample was pulverized and crushed to obtain a Blaine specific surface area of ​​4,000 cm2. 2 / g. Repair admixture C: β-2CaO SiO2. Reagent grade calcium carbonate and reagent grade silicon dioxide were mixed in a molar ratio of 2:1. The mixed sample was heat treated at 1,400°C for 2 hours, allowed to cool to room temperature, crushed, and the same heat treatment was repeated until the peak of γ-2CaO SiO2 was no longer observed by XRD. After the peak of only β-2CaO SiO2 was observed, the Blaine specific surface area was measured to be 4,000 cm 2 / g. Rapid hardening material A: Amorphous calcium aluminate prepared to contain 43% CaO and 53% Al2O3, melted and rapidly cooled in an electric furnace, with a vitrification rate of 98% or more and a Blaine specific surface area of ​​6,050 cm 2 / g, and a mixture of 100 parts by mass of calcium aluminate and 150 parts by mass of gypsum was used. The CaO / Al2O3 molar ratio of calcium aluminate was 1.5. Rapid hardening material B: Alumina cement No. 1, manufactured by Denka (CaO / Al2O3 molar ratio of calcium aluminate: 1.0) Accelerator C: calcium formate, reagent Accelerator D: calcium nitrate, reagent

[0066] <Measurement items> Flowability: In accordance with JISA1171, measured immediately after mixing using the JIS flow value at 20°C. Self-healing effect: In accordance with JISA6206, repair material specimens measuring 10cm x 10cm x 40cm were prepared under rebar restraint conditions. After 56 days, strain gauges were attached to the surface of the specimen and a bending test was conducted. The bending test was terminated when cracks measuring 0.1mm appeared. The specimen was then left to stand for 28 days at 98% relative humidity and 35°C, followed by 7 days at 60% relative humidity and 20°C. This cycle was repeated five times, and the percentage of the area where the cracks were closed (closed area / cracked area) was measured. Compressive strength: In accordance with JSCE-G 505, specimens of the repair material were prepared in a Φ5 x 10 cm formwork, removed from the form after one day, and then cured in water at 20°C for 28 days. They were then air-dried and naturally carbonated. The compressive strength was measured at 700 days. Abrasion resistance: Repair material specimens were prepared in doughnut-shaped molds measuring 100mm diameter x 10mm, demolded after one day, and then cured in water at 20°C until the material was 28 days old, after which it was naturally carbonated in air-dried curing. At 700 days old, the specimens were subjected to a Taber abrasion test (weight loss method). The test conditions were a load of 1kg, an abrasion wheel H-22, and 1,000 cycles. The measurement results are shown in Table 1 below.

[0067] [Table 1]

[0068] From the results in Table 1, it was confirmed that, as shown in the examples, the inclusion of a repair admixture containing a specific non-hydraulic material can further enhance high fluidity and self-healing effects, and also improve compressive strength and abrasion resistance. [Industrial Applicability]

[0069] The repair material of the present invention contains a specific non-hydraulic material, which allows for high fluidity and enhanced self-healing effects, and also provides a repair material, repair mortar composition, and hardened body that become dense through natural carbonation and have improved compressive strength and abrasion resistance, and can be used in a wide range of applications, including civil engineering and construction.

Claims

1. γ-2CaO.SiO ２ , 3CaO・2SiO ２ , α-CaO.SiO ２ and calcium magnesium silicate, and a repair material comprising cement, a polymer emulsion, fibers, and fine aggregate, In the repair material, SO ３ A repair material having an amount of 0.5% by mass or more and 10.0% by mass or less, and an amount of MgO of 0.1% by mass or more and 3.0% by mass or less.

2. γ-2CaO.SiO ２ , 3CaO・2SiO ２ , α-CaO.SiO ２ and calcium magnesium silicate, and a repair admixture containing one or more non-hydraulic compounds selected from the group consisting of cement, a polymer emulsion, fibers, and fine aggregate; The repair material contains Li in the non-hydraulic compound, and the Li content in the non-hydraulic compound is 0.001 to 1.0 mass % in terms of oxide.

3. The repair material according to claim 1 or 2, further comprising an expanding agent.

4. It also contains rapid hardening materials, The hardening agent contains calcium aluminate, The calcium aluminate CaO / Al ２ O ３ the molar ratio is 1.0 or more and 3.0 or less, The repair material according to any one of claims 1 to 3, wherein the content of the calcium aluminate is 2 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the cement.

5. The repair material according to any one of claims 1 to 4, wherein the content of the fine aggregate is 40 parts by mass or more and 300 parts by mass or less per 100 parts by mass of the cement.

6. A repair mortar composition comprising the repair material according to any one of claims 1 to 5 and water.

7. A hardened body obtained by using the repair mortar composition according to claim 6.

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