JP7744792B2 - Grout material, grout mortar composition and hardened product - Google Patents

Description

The present invention relates to grout materials, grout mortar compositions, and hardened products made from grout mortar compositions, primarily used in the civil engineering and construction industries.

Grout materials are used to improve the workability and filling properties of mortar and concrete, and to facilitate grouting work.
Its main applications include the construction of underground structures, the installation of bridge bearings, the installation of various types of machinery, and the filling of gaps in walls and columns in earthquake-resistant reinforcement. In order to fill and integrate gaps in structures, it is required that it has (1) the required fluidity depending on the filling location and filling method, (2) non-shrinkage properties that prevent bleeding, settlement, and the generation of voids after filling, and (3) various strengths that are required depending on the conditions of use of the structure (see, for example, non-patent document 1).

Hardened cement paste loses volume as the cement hydrates or dries, which can lead to cracks and a decrease in adhesion to existing structures. Cracks not only ruin the aesthetic appearance, but can also have a negative impact on the stability, waterproofing, and watertightness of the structure.
Therefore, the expanding materials used to compensate for cement shrinkage, prevent cracking, and maintain adhesion to structures include, for example, 3CaO.3Al ₂ O _{3.CaSO 4} (auin), calcium sulfoaluminate-based materials (auin-based expanding materials) whose main components are CaSO ₄ and CaO, lime-based materials whose main component is free lime (lime-based expanding materials), and expanding materials containing free lime, hydraulic materials, and gypsum.

A grout material has been proposed that combines cement, expansive materials, and specific water-reducing agents to have low temperature dependency, significantly high fluidity and filling retention, and long-term strength-enhancing effects (see, for example, Patent Document 1).
Furthermore, a high-strength grout material has been proposed that has excellent fluidity, suppresses bubble generation, and maintains an optimum length change rate and volume expansion rate (see, for example, Patent Document 2).

However, conventional grout materials containing expansive additives have the risk of losing their fluidity and expansion performance when stored beyond the quality assurance period due to moisture seeping in from the outside, especially at high temperatures. Furthermore, when applied to relatively large areas such as mass concrete, the high heat of hydration can cause drying shrinkage cracks, and excessive use of water-reducing agents to improve filling properties can lead to the risk of solid-liquid separation of the grout.
Therefore, there is a need to reduce the heat of hydration and drying shrinkage, and to improve filling properties without using an excessive amount of water-reducing agent.

Patent No. 3894780 International Publication No. 2007/029399

New Admixtures for Cement and Concrete, pp. 304-307, Yoshio Kasai and Etsuro Sakai, Gijutsu Shoin, published January 15, 2007

The objective of the present invention is to provide a grout material, grout mortar composition, and hardened product that reduces hydration heat and drying shrinkage and improves filling properties without using an excessive amount of water-reducing agent.

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 a grout material prepared by combining specific fine aggregates has low heat of hydration and drying shrinkage, and also improves filling properties, and they have thus completed the present invention. The gist of the present invention is as follows.
[1] A grout material containing cement, an expansive agent, a gas foaming substance, a water reducing agent, fine aggregate A, and fine aggregate B, wherein the particle diameter of the fine aggregate A is less than 1.2 mm and the average particle diameter is 0.4 to 0.8 mm, the particle diameter of the fine aggregate B is in the range of 1.2 to 10 mm and the average particle diameter is 2 to 9 mm, the mass ratio of the fine aggregate A to the fine aggregate B (fine aggregate A/fine aggregate B) is 50 to 200%, and the angle of repose is 40 to 55°.
[2] The grout material described in [1] above, wherein the expansive material contains ternesite, and the content of the ternesite is 0.05 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the expansive material.
[3] The grout material according to [1] or [2] above, wherein the fine aggregate A has a reduction in coarse particle ratio of 70% or more and 100% or less according to JIS A1121 "Abrasion test of coarse aggregate using a Los Angeles tester."
[4] The chemical components of the fine aggregate A are such that the proportion of CaO is 85% by mass or more, the proportion of SiO ₂ is 0.2% by mass or more and 14% by mass or less, the proportion of K ₂ O is 40 ppm by mass or more and 3,000 ppm by mass or less, and the proportion of SO ₃ is 40 ppm by mass or more and 3,000 ppm by mass or less, and the chemical components of the fine aggregate B are such that the proportion of SiO ₂ is 75% by mass or more. [1] The grout material according to any one of [1] to [3] above.
[5] The grout material according to any one of [1] to [4] above, wherein the chemical components of the fine aggregate A are such that the proportion of Fe ₂ O ₃ is 0.1 mass% or more and 3.0 mass% or less, and the proportion of Al ₂ O ₃ is 0.1 mass% or more and 3.0 mass% or less.
[6] The grout material according to any one of [1] to [5] above, wherein the content of the fine aggregate A is 50 parts by mass or more and 300 parts by mass or less relative to 100 parts by mass of the cement, and the content of the fine aggregate B is 50 parts by mass or more and 300 parts by mass or less relative to 100 parts by mass of the cement.
[7] A grout mortar composition containing the grout material according to any one of [1] to [6] above and water.
[8] A hardened body obtained by using the grout mortar composition described in [7] above.

The present invention provides a grout material, grout mortar composition, and hardened product that reduces hydration heat and drying shrinkage, and improves filling properties without using an excessive amount of water-reducing agent.

The present invention will be described in detail below.
In this specification, parts and percentages are by mass unless otherwise specified.
In addition, the term "grout mortar" as used in this specification is a general term for paste containing no coarse aggregate and mortar containing fine aggregate.

The grout material of the present invention is a grout material containing cement, an expansive agent, a gas foaming substance, a water reducing agent, fine aggregate A, and fine aggregate B, wherein the particle size of the fine aggregate A is less than 1.2 mm and the average particle size is 0.4 to 0.8 mm, the particle size of the fine aggregate B is in the range of 1.2 to 10 mm and the average particle size is 2 to 9 mm, the mass ratio of the fine aggregate A to the fine aggregate B (fine aggregate A/fine aggregate B) is 50 to 200%, and the angle of repose is 40 to 55°.
The inventors have focused on fine aggregate and discovered that the angle of repose and the ratio of two types of fine aggregate with specific particle sizes affect the packing properties of grout materials. The present invention was completed based on this finding.
In other words, if the angle of repose of the grout material is less than 40° or exceeds 55°, or if the average particle size of fine aggregate A is less than 0.4 mm or exceeds 0.8 mm, or if the average particle size of fine aggregate B is less than 2 mm or exceeds 9 mm, or if the mass ratio of fine aggregate A to fine aggregate B (fine aggregate A/fine aggregate B) is less than 50% or exceeds 200%, the filling ability will be low.

<Angle of repose>
The angle of repose of the grout material of the present invention is 40 to 55°. A repose angle within this range improves packing properties. From the above viewpoints, the angle of repose is preferably 42 to 50°, more preferably 43 to 49°, and even more preferably 45 to 48°.
The angle of repose of a grout material can be adjusted, for example, by changing the particle size and proportions of the cement, expansive agent, gas-foaming agent, water-reducing agent, fine aggregate A, and fine aggregate B contained in the grout material. The particle size of the cement and fine aggregate, which are the main components of the grout material of the present invention, has a particularly large effect, with smaller particle sizes tending to result in smaller angles of repose. For example, a grout material with an angle of repose of 40 to 55° can be obtained by including 20 to 40% by mass of fine aggregate A, 20 to 60% by mass of fine aggregate B, and 10 to 40% by mass of cement with a particle size of 5 to 20 μm. Furthermore, the angle of repose of the grout material can be adjusted by using a finer cement depending on the materials used. Furthermore, when a large amount of expansive agent is added, the angle of repose can be adjusted by changing its particle size, making it possible to achieve the effects of the present invention.
The angle of repose was obtained by allowing the measurement sample to fall naturally onto a table with a diameter of 80 mm using a funnel and measuring the angle of the peak of the powder that formed.

<Fine aggregate>
The grout material of the present invention has two types of fine aggregate, one of which (fine aggregate A) has a particle diameter of less than 1.2 mm. When the particle diameter of fine aggregate A is within this range, the filling property is improved. From the above viewpoints, the particle diameter of fine aggregate A is preferably 1.1 mm or less, and more preferably 1.0 mm or less. Furthermore, the average particle diameter of fine aggregate A is 0.4 to 0.8 mm. When the average particle diameter of fine aggregate A is within this range, the filling property is improved. From the above viewpoints, the average particle diameter of fine aggregate A is preferably 0.5 to 0.8 mm, and more preferably 0.6 to 0.8 mm.
The grout material of the present invention also contains another fine aggregate (fine aggregate B) with a particle size ranging from 1.2 to 10 mm, with an average particle size ranging from 2 to 9 mm. When the particle size of fine aggregate B is within this range, a good balance with fine aggregate A is achieved, making it easier to obtain the suitable angle of repose. From the above perspectives, the particle size of fine aggregate B is preferably within the range of 1.2 to 8 mm, and more preferably within the range of 1.2 to 6 mm.
Furthermore, when the average particle size of fine aggregate B is within the above range, a good balance with fine aggregate A is achieved, the above-mentioned preferable angle of repose is obtained, and the effects of the present invention are achieved. From the above viewpoints, the average particle size is more preferably 3 to 7 mm, and even more preferably 4 to 5 mm.
Furthermore, the mass ratio of the fine aggregate A to the fine aggregate B (fine aggregate A/fine aggregate B) is 50 to 200%. The effects of the present invention are achieved when the mass ratio is within this range. From the above perspectives, the mass ratio of the fine aggregate A to the fine aggregate B is more preferably 70 to 180%, and even more preferably 90 to 160%. The mass ratio here is the result of dividing the mass of the fine aggregate A by the mass of the fine aggregate B, expressed as a percentage.
The particle size and average particle size were determined from the weight passing percentage by sieving.

<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 (ecocements) 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 (e.g., 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 heat of hydration, drying shrinkage, and filling properties.

From the viewpoints of production costs and strength development, the cement used in the present invention preferably has a Blaine specific surface area value of 2,500 cm ² /g or more and 7,000 cm ² /g or less, more preferably 2,750 cm ² /g or more and 6,000 cm ² /g or less, and even more preferably 3,000 cm ² /g or more and 4,500 cm ² /g or less.
The Blaine specific surface area value is determined in accordance with JIS R 5201 (physical testing method for cement).

<Expansive material>
The expanding agent used in the present invention is not particularly limited, and any agent can be used as long as it generates an expansive hydrate and suppresses bleeding.
Known expansive materials include free lime, free magnesia, calcium ferrite, ettringite, lime, and ettringite-lime composites, and although there are no particular limitations, those containing free lime are preferred from the viewpoint of long-term stability. Examples of materials containing free lime include free lime-anhydrous gypsum systems, free lime-hydraulic compound systems, and free lime-hydraulic compound-anhydrous gypsum systems.

The expansive material used in the present invention preferably contains ternesite. ternesite is a mineral expressed as _{5CaO.2SiO2.SO3} , and promotes hydraulic reaction. Furthermore, since ternesite itself is almost unreactive, it is presumed to act as _a filler and improve fluidity retention. Therefore, the fluidity retention effect can be maintained even at high temperatures.
The content of ternesite is preferably 0.05 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass or more and 18 parts by mass or less, and even more preferably 0.5 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the expanding agent. By keeping the content of ternesite within the above range, both the hardening acceleration and the fluidity retention can be improved.

In the present invention, it is preferable to use a free lime-hydraulic compound-anhydrous gypsum system because of its good expansion performance, and it is particularly preferable to use a system having a free lime content of more than 40% by mass.
Here, examples of the hydraulic compound include one or more of auin, calcium ferrite, calcium aluminoferrite, calcium silicate, calcium aluminate, etc. In the present invention, commercially available expansive materials and static crushing materials can be used as the expansive material.
Expansion materials and static crushing materials are commercially available from various companies, and representative examples include "Denka CSA#20" and "Denka Power CSA" manufactured by Denka Company Ltd., "Expan,""Hyperexpan,""N-EX," and "Blister" manufactured by Pacific Materials Corporation, and crushed products thereof.

The particle size of the expanding agent used in the present invention is not particularly limited, but a Blaine specific surface area value in the range of 2,000 cm ² /g to 25,000 ^{cm 2} /g is preferred, 2,200 cm ² /g to 15,000 ^{cm 2} /g is more preferred, and 2,400 cm ² /g to 10,000 cm ² /g is even more preferred. When the Blaine specific surface area value of the expanding agent is equal to or greater than the above lower limit, bleeding can be suppressed. Furthermore, when the Blaine specific surface area value of the expanding agent is equal to or less than the above upper limit, sufficient expandability can be obtained.

The content of the expansive agent used in the present invention is preferably 0.5 to 20 parts by mass, more preferably 1 to 18 parts by mass, and even more preferably 2 to 15 parts by mass, per 100 parts by mass of cement. When the content of the expansive agent is above the above lower limit, it becomes easier to achieve a crack suppression effect. On the other hand, when the content of the expansive agent is below the above upper limit, good strength development is achieved. When the content of the expansive agent is within the above range, it becomes easy to obtain a grout material that satisfies the effects of the present invention, i.e., a grout material that has low heat of hydration, drying shrinkage, and excellent filling properties.

<Gas foaming material>
The gas foaming substance used in the present invention is a substance used for the purpose of preventing the unhardened grout material from sinking or shrinking due to bleeding after application of the grout mortar composition. The gas foaming substance used in the present invention is not particularly limited as long as it generates gas after being mixed with water.

Examples of gas foaming substances include oily substances such as vegetable oils and mineral oils. Examples of gas foaming substances include powdery substances such as flaky aluminum powder surface-treated with stearic acid and aluminum powder produced by atomization. Examples of gas foaming substances include nitrogen gas foaming substances that foam nitrogen gas in an alkaline atmosphere, such as azo compounds, nitroso compounds, and hydrazine derivatives. Examples of gas foaming substances include percarbonates such as sodium percarbonate, potassium percarbonate, and ammonium percarbonate; perborates such as sodium perborate and potassium perborate; permanganates such as sodium permanganate and potassium permanganate; and peroxides such as hydrogen peroxide.
As the gas foaming substance used in the present invention, it is preferable to use aluminum powder whose surface has been treated with stearic acid or the like, because this has a great effect of suppressing subsidence.

The nitrogen gas foaming substance that can be used in the present invention contains a compound that generates nitrogen gas by reacting with alkali generated when cement contained in the grout material is mixed with water, and may also generate gases such as carbon monoxide, carbon dioxide, and ammonia as by-products.
The nitrogen gas foaming agent used in the present invention is not particularly limited as long as it can be used to integrate the material with the structure, to prevent the unhardened grout mortar from settling or shrinking, and to improve crack resistance when left in a dry state.

The content of the gas foaming substance is preferably 0.0001 to 1 part by mass, more preferably 0.0005 to 0.5 parts by mass, and even more preferably 0.001 to 0.2 parts by mass, per 100 parts by mass of cement. A content of the gas foaming substance equal to or above the lower limit mentioned above can provide a sufficient initial expansion effect. Furthermore, a content of the gas foaming substance equal to or below the upper limit mentioned above can provide good strength development.

<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 grout mortar.

The water-reducing agent used in the present invention is not particularly limited, and examples thereof include naphthalene-based water-reducing agents, melamine-based 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 those manufactured by NMB Corporation under the trade name "Rheobuild SP-9 Series," Kao Corporation under the trade name "Mighty 2000 Series," and Nippon Paper Industries Co., Ltd. under the trade name "Sunflow HS-100." Melamine-based water-reducing agents include those manufactured by Sika Japan under the trade name "Sikament 1000 Series" and Nippon Paper Industries Co., Ltd. under the trade name "Sunflow HS-40." Aminosulfonic acid-based water-reducing agents include those manufactured by Fujisawa Pharmaceutical Co., Ltd. under the trade name "Paric FP-200 Series." Polycarboxylic acid-based water-reducing agents include those manufactured by NMB Corporation under the trade name "Rheobuild SP-8 Series," Grace Chemicals Corporation under the trade name "Darlex Super 100PHX," and Takemoto Oil & Fat Co., Ltd. under the trade names "Chupol HP-8 Series" and "Chupol HP-11 Series."
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 "Cellflow 110P" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. Melamine-based water-reducing agents include "Melment F10M" manufactured by BASF Pozzolith AG Polycarboxylic acid-based water-reducing agents include "CAD9000P" manufactured by Kao Corporation.

The content of the water-reducing agent is preferably 0.1 to 5 parts by mass, in solids equivalent, per 100 parts by mass of cement, more preferably 0.2 to 4 parts by mass, and even more preferably 0.3 to 3.5 parts by mass. By ensuring that the content of the water-reducing agent is at or above the lower limit, sufficient fluidity can be achieved. Furthermore, by ensuring that the content of the water-reducing agent is at or below the upper limit, material separation can be suppressed.

<Fine aggregate A>
The chemical components of the fine aggregate A used in the present invention preferably contain CaO at a rate of 85% by mass or more _{and SiO2} at a rate of 0.2% by mass to 14% by mass or less. When the CaO and _SiO2 contents of the chemical components of the fine aggregate A are within the above ranges, a grout material with low heat of hydration, low drying shrinkage, and excellent filling properties 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% by mass or more and 13% by mass or less, more preferably 0.3% by mass or more and 11% by mass or less, and even more preferably 0.4% by mass or more and 10% by mass or less.
In order to ensure that the chemical composition of fine aggregate A falls within the above and later-described ranges, silica sand, calcite, scapolite, a metamorphic rock, quartz, a igneous rock, potassium feldspar, and other rocks are mixed together to prepare the fine aggregate. The chemical composition is checked by fluorescent X-ray diffraction to ensure that it falls within the ranges specified in the present invention, and the various rocks are mixed and adjusted accordingly. The chemical composition of fine aggregate A used in the present invention is calculated in terms of oxides.

The fine aggregate A used in the present invention preferably contains, as chemical components, K ₂ O, SO ₃ , Fe ₂ O ₃ , and Al ₂ O _3. When the fine aggregate A contains K ₂ O, SO ₃ , Fe ₂ O ₃ , and Al ₂ O ₃ , it can contribute to low heat of hydration, low drying shrinkage, and good packing properties.
The proportion of K ₂ O is preferably 40 mass ppm or more and 3,000 mass ppm or less, more preferably 50 mass ppm or more and 2,500 mass ppm or less, even more preferably 60 mass ppm or more and 2,250 mass ppm or less, and even more preferably 70 mass ppm or more and 2,000 mass ppm or less.
The proportion of SO ₃ is preferably 40 mass ppm or more and 3,000 mass ppm or less, more preferably 50 mass ppm or more and 2,500 mass ppm or less, even more preferably 60 mass ppm or more and 2,250 mass ppm or less, and even more preferably 70 mass ppm or more and 2,000 mass ppm or less.
The proportion of _Fe2O3 is preferably 0.1 mass% or more _and 3.0 mass% or less, more preferably 0.13 mass% or more and 2.5 mass% or less, and even more preferably 0.15 mass% or more and 2.0 mass% or less.
The proportion of Al ₂ O ₃ is preferably 0.1 mass % or more and 3.0 mass % or less, more preferably 0.13 mass % or more and 2.5 mass % or less, and even more preferably 0.15 mass % or more and 2.0 mass % or less.

The fine aggregate A used in the present invention preferably exhibits a reduction in the coarseness ratio of 70% to 100% in accordance with JIS A1121, "Abrasion Test of Coarse Aggregate Using a Los Angeles Tester," more preferably 75% to 99%, even more preferably 80% to 98%, and even more preferably 85% to 97%. When the reduction in the coarseness ratio of fine aggregate A is equal to or greater than the lower limit, the packing property can be improved. Furthermore, when the reduction in the coarseness ratio of fine aggregate is equal to or less than the upper limit, the packing property can be improved. In this specification, the "coarseness ratio of fine aggregate" refers to a value obtained from the results of sieving, and is an index that indicates the approximate size of the fine aggregate. In this specification, the "reduction in the coarseness ratio of fine aggregate" refers to the percentage reduction in the coarseness ratio after the Los Angeles test, comparing the coarseness ratio before and after the test.
In order to reduce the coarseness ratio of the fine aggregate within the above range, silica sand, calcite, scapolite, which is a metamorphic rock, quartz, which is an igneous rock, potassium feldspar, etc. are mixed to prepare the aggregate. The reduction in the coarseness ratio of the fine aggregate is adjusted by mixing the various rocks while checking the abrasion test of the coarse aggregate using a Los Angeles tester so that it falls within the range of the present invention.
As long as the reduction in the coarse particle ratio of the fine aggregate is within the above range, the place of production or the origin of the fine aggregate is not particularly limited.

The content of fine aggregate A is preferably 50 to 300 parts by mass, more preferably 75 to 250 parts by mass, and even more preferably 150 to 230 parts by mass, per 100 parts by mass of cement. Having a content of fine aggregate A equal to or greater than the above lower limit reduces the amount of heat generated, suppresses shrinkage, and inhibits cracking. Furthermore, having a content of fine aggregate equal to or less than the above upper limit results in a grout material with excellent filling properties.

<Fine aggregate B>
The chemical components of the fine aggregate B used in the present invention preferably contain 75% by mass or more of _SiO2 . When the chemical components of the fine aggregate B contain 75% by mass or more of _SiO2 , a grout material with low heat of hydration, low drying shrinkage, and excellent filling properties can be obtained.
From the above viewpoint, the proportion of SiO ₂ is more preferably 78% by mass or more, and even more preferably 80% by mass or more.
In order to ensure that the chemical composition of fine aggregate B falls within the above and later-described ranges, silica sand, calcite, scapolite, a metamorphic rock, quartz, a igneous rock, potassium feldspar, and other rocks are mixed to prepare the fine aggregate B. The chemical composition of the fine aggregate B used in the present invention is determined by calculating the oxide equivalent.

The content of fine aggregate B is preferably 50 to 300 parts by mass, more preferably 70 to 280 parts by mass, and even more preferably 90 to 250 parts by mass, per 100 parts by mass of cement. Having a content of fine aggregate B equal to or greater than the above lower limit reduces the amount of heat generated, suppresses shrinkage, and inhibits cracking. Furthermore, having a content of fine aggregate equal to or less than the above upper limit results in a grout material with excellent filling properties.

<Silica fine powder>
The grout material of the present invention can contain, in addition to cement, expansive agent, gas foaming substance, water reducing agent, fine aggregate A, and fine aggregate B, silica fine powder in order to improve strength development, acid resistance, ensure usable life, and improve dimensional stability.

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.
Although there are no limitations on the type of silica fume, from the viewpoint of fluidity, it is more preferable to use silica fume containing 10% or less of _ZrO2 as an impurity or acidic silica fume. Acidic silica fume refers to silica fume that, when 1 g of silica fume is added to 100 cc of pure water and stirred, the supernatant liquid exhibits an acidic pH of 5.0 or less.

The fineness of the siliceous fine powder is not particularly limited, but it is generally preferable that the Blaine value of ground granulated blast furnace slag and fly ash is in the range of 3,000 cm ² /g to 9,000 cm ² /g, and that the BET specific surface area of silica fume is in the range of 20,000 cm ² /g to 300,000 cm ² /g.

The content of 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 a content of siliceous fine powder above the lower limit mentioned above can improve strength development, acid resistance, ensure usable time, and dimensional stability. Furthermore, having a content of siliceous fine powder below the upper limit mentioned above can improve fluidity, adhesion to rebar, and anti-corrosion properties.

In the present invention, one or more of the following additives may be used, provided they do not adversely affect performance: setting regulators, air-entraining agents, rust inhibitors, water repellents, antibacterial agents, colorants, antifreeze agents, admixtures such as finely divided limestone, finely divided slowly cooled blast furnace slag, 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; fibrous materials such as steel fiber, vinylon fiber, carbon fiber, and wollastonite fiber; polymers; clay minerals such as bentonite and sepiolite; and anion exchangers such as hydrotalcite.

In the grout material of the present invention, the method of 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.

<Grout mortar composition>
The grout mortar composition of the present invention contains the grout material of the present invention described above and water, and is prepared by kneading the grout 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 5 to 70 parts by mass, more preferably 7 to 65 parts by mass, and even more preferably 9 to 60 parts by mass, per 100 parts by mass of grout material. By having the amount of mixing water equal to or greater than the above-mentioned lower limit, it is possible to prevent a decrease in fluidity and an extremely large heat generation. Furthermore, by having the amount of mixing water equal to or less than the above-mentioned upper limit, it is possible to ensure strength development.

In the present invention, the method for mixing the grout 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 conventional high-speed grout mixer, or a twin-screw forced mixer.

When mixing with a hand mixer or high-speed grout mixer, it is preferable to first charge a specified amount of water into a container such as a pail or mixer, then add the grout material while rotating the mixer, and mix for at least three minutes. When mixing with a forced mixer, it is preferable to first charge the grout material into the mixer, then add the specified amount of water while rotating the mixer, and mix for at least four minutes. Mixing for less than the specified time may result in insufficient mixing, making it difficult to achieve the appropriate fluidity of the grout mortar.

<Cured body>
The mixed grout mortar composition is usually pumped to the application site using a manual injection gun, a diaphragm hand pump, or a squeeze type mortar pump, and then filled and applied to form a hardened body using the grout mortar composition of the present invention.

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

Experimental Example 1 (No. 1-1 to 1-9)
A grout material was prepared containing 12.0 parts by mass of expansive material, 0.0025 parts by mass of gas foaming material, 1.5 parts by mass of water reducing agent, and 300 parts by mass of fine aggregate (A+B) per 100 parts by mass of cement.
100 parts by mass of the obtained grout material was mixed with 15 parts by mass of water to prepare a grout mortar composition.
The prepared grout mortar compositions were measured for simple adiabatic temperature rise, drying shrinkage, and filling property. The results are shown in Table 1. The drying shrinkage was expressed as a change in length. The larger the absolute value of the numerical value, the larger the drying shrinkage.

<Materials used>
Cement: trial cement (various commercially available pure chemicals were used to adjust the raw materials and chemical components of the cement factory, and pure anhydrous gypsum was used to adjust the amount of SO ₃ ), chlorine content 1.5 mass% ppm, Blaine value 3,450 cm ² /g
-Expansive additive: CaO raw material, _{Al2O3 raw} material, _SiO2 raw material, and _CaSO4 raw material were blended, mixed and crushed, and then fired at 1,200°C to synthesize clinker, which was then crushed using a ball mill to a Blaine specific surface area of 3,000 ^cm2 /g. The mineral composition of ternesite was calculated based on the chemical composition determined from fluorescent X-rays and the identification results of powder X-ray diffraction. The amount of ternesite contained in 100 parts by mass of the expansive additive is shown in Table 1.
Gas foaming agent: flaky aluminum powder surface-treated with stearic acid, commercially available product. Setting regulator: a mixture of 25 parts of reagent-grade citric acid and 75 parts of reagent-grade potassium carbonate. Water reducing agent: a naphthalene-based water reducing agent, commercially available (Dai-ichi Kogyo Seiyaku Co., Ltd.'s "Selflo-110P")
Water: Tap water Fine aggregates A and B: The tests were conducted using the fine aggregates shown in Table 1. The chemical components of the fine aggregates were measured by X-ray fluorescence analysis. To prepare the chemical components, silica sand (produced in Aichi Prefecture), calcite (CaCO ₃ ), scapolite ((Na, Ca, K) 4Al ₄ Si ₉ O ₂₄ (Cl, CO ₃ , SO ₄ )), quartz (SiO ₂ ), igneous rock, and potassium feldspar (KAlSi ₃ O ₈ ) were mixed.
The average particle size is a value determined from the weight passing percentage by the sieving method as described above.

<Measurement items>
- Simplified adiabatic temperature rise: The maximum temperature was measured immediately after mixing in a 2 L simple pot.
Length change (drying shrinkage): The length change at 28 days of age was measured in accordance with JIS A 6202.
Static flow: According to JIS R 5201, measurements were taken immediately after mixing and after 15 and 30 minutes.
Filling rate: A 1000 x 1000 mm acrylic plate was fixed at a height of 100 mm in the center of a 1200 x 1200 mm formwork. A hose nozzle was inserted into the back of the gap, and concrete was filled while being pulled toward the front. After filling, the volume of the void was measured.

The results in Table 1 confirm that using a grout material with a specific angle of repose that contains two types of fine aggregate with specific particle sizes in a specific ratio can reduce hydration heat and drying shrinkage and improve filling properties.

Experimental Example 2 (No. 1-3, No. 2-1 to 2-4)
The same procedure as in Experimental Example 1 was carried out, except that the grout mortar composition was prepared by blending the fine aggregates shown in Table 2. The results are also shown in Table 2. The amount of ternesite used in the expansive additive was 5 parts by mass per 100 parts by mass of the expansive additive.
The abrasion test of fine aggregate using the Los Angeles tester was first conducted by loading 5 kg of fine aggregate A and six iron balls into the tester. The average diameter of the iron balls was approximately 46.8 mm, and each ball weighed 390 to 445 g. The tester was then rotated at 500 revolutions per minute (30 revolutions per minute). The fine aggregate sampled from the tester was then sieved using metal mesh sieves with mesh sizes of 5 mm, 2.5 mm, 1.2 mm, 0.6 mm, 0.3 mm, and 0.15 mm. The coarse aggregate ratio (R1) of fine aggregate A before loading into the Los Angeles tester was compared with the coarse aggregate ratio (R2) of fine aggregate A after loading into the Los Angeles tester, and the decrease in coarse aggregate ratio after the test was calculated using the following formula. The coarse aggregate ratios R1 and R2 were calculated in accordance with JIS A 1102.
Reduction in coarse grain ratio = R2/R1
The grout materials used in Nos. 2-1 to 2-4 had the same composition as in No. 1-3. That is, the particle size, average particle size, fine aggregate A/fine aggregate B (mass ratio), and angle of repose of fine aggregate A and fine aggregate B were the same as in No. 1-3.

The results in Table 2 confirm that by using a grout material with a specific angle of repose that contains two types of fine aggregate with specific particle sizes in a specific ratio, and that contains fine aggregate with specific chemical components and a specific range of reduction in coarseness, it is possible to reduce hydration heat and drying shrinkage and improve filling properties.

Experimental Example 3 (No. 1-3, No. 3-1 to 3-4)
The same procedure as in Experimental Example 1 was carried out except that the grout mortar compositions were prepared by blending the fine aggregates shown in Table 3. The results are also shown in Table 3.
The grout materials used in Nos. 3-1 to 3-4 had the same composition as in No. 1-3. That is, the particle size, average particle size, fine aggregate A/fine aggregate B (mass ratio), and angle of repose of fine aggregate A and fine aggregate B were the same as in No. 1-3.

The results in Table 3 confirm that using a grout material with a specific angle of repose that contains two types of fine aggregate with specific particle sizes and specific chemical compositions in specific ratios can reduce hydration heat and drying shrinkage and improve filling properties.

The grout material of the present invention is prepared by combining specific fine aggregates, and provides a grout mortar composition that reduces hydration heat and drying shrinkage and improves filling properties. Therefore, this grout mortar composition can be used in a wide range of applications, including steel plate wrapping methods for bridge piers, filling methods for large support bases, anchoring materials for reinforcing steel bars, other gap filling, concrete cross-section repair, self-leveling flooring materials, as well as civil engineering and construction applications.

Claims (8)

A grout material containing cement, an expansive agent, a gas foaming agent, a water reducing agent, fine aggregate A, and fine aggregate B,
the particle size of the fine aggregate A is less than 1.2 mm and has an average particle size of 0.4 to 0.8 mm, the particle size of the fine aggregate B is in the range of 1.2 to 10 mm and has an average particle size of 2 to 9 mm, and the mass ratio of the fine aggregate A to the fine aggregate B (fine aggregate A/fine aggregate B) is 50 to 200%,
The chemical components of the fine aggregate A are such that the proportion of CaO is 85% by mass or more and the proportion of SiO2 _is 0.2% by mass or more and 14% by mass or less,
The chemical composition of the fine aggregate B is such that the proportion of SiO2 _is 75% by mass or more,
A grout material with an angle of repose of 40 to 55 degrees. The expanding material contains ternesite,
The grout material according to claim 1, wherein the content of the ternesite is 0.05 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the expansive agent. The grout material according to claim 1 or 2, wherein the fine aggregate A exhibits a reduction in coarseness ratio of 70% or more and 100% or less according to JIS A1121 "Abrasion test of coarse aggregate using a Los Angeles testing machine." The grout material according to any one of claims 1 to 3, wherein the chemical components of the fine aggregate A include a K ₂ O ratio of 40 mass ppm or more and 3,000 mass ppm or less and a SO ₃ ratio of 40 mass ppm or more and 3,000 mass ppm or less. The grout material according to any one of claims 1 to 4, wherein the chemical components of the fine aggregate A include a proportion of _{Fe2O3 of} 0.1 mass% or more and 3.0 mass% or less, _and a proportion of _Al2O3 of 0.1 mass% or more and 3.0 mass% or less. The grout material according to any one of claims 1 to 5, wherein the content of the fine aggregate A is 50 to 300 parts by mass per 100 parts by mass of the cement, and the content of the fine aggregate B is 50 to 300 parts by mass per 100 parts by mass of the cement. A grout mortar composition containing the grout material according to any one of claims 1 to 6 and water. A hardened body obtained using the grout mortar composition described in claim 7.