Ultra-fast hardening mortar material for grouting, hardened mortar body

Abstract

To provide an ultra-rapid hardening mortar material for grout, which can make a long-term expansion coefficient moderate.SOLUTION: There is provided an ultra-rapid hardening mortar material for grout, in which the mortar material contains cement, calcium aluminate and gypsum, and has expansion coefficients of 0.005-0.5%, 0.01-0.75%, and 0.015-1.0% at material ages of 3 days, 7 days, and 28 days, respectively.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to an ultrafast-setting mortar material for grouting and a hardened mortar body. [Background technology]

[0002] Grout is used in the construction of underground structures, the installation of bridge bearings, the installation of various types of machinery, and the filling of gaps between walls and columns in seismic reinforcement. In recent years, there has been an increasing demand for rationalized construction methods, so there is a need for mortar materials that have ultra-fast hardening properties, self-compacting and self-leveling capabilities.

[0003] Mortar materials decrease in volume as cement hydrates or dries, so when used as grout, there is a risk of cracking or reduced adhesion to existing structures. The occurrence of cracks not only impairs the aesthetics but also poses a risk of adversely affecting the stability, waterproofing, and watertightness of the structure.

[0004] Therefore, in order to compensate for cement shrinkage, suppress crack formation, and maintain adhesion to the structure, various types of expanders are used, such as 3CaO·3Al2O3·CaSO4 (hauyne), calcium sulfoaluminate-based expanders mainly composed of CaSO4 and CaO (hauyne-based expanders), lime-based expanders mainly composed of free lime (lime-based expanders), and expanders containing free lime, hydraulic substances, and gypsum.

[0005] As materials with excellent ultrafast hardening properties, for example, ultrafast hardening cement compositions are known in which metal sulfates or fly ash are added to calcium aluminates or gypsum to ensure fluidity (Patent Documents 1-3). Furthermore, ultrafast-setting cement containing calcium aluminate, gypsum, and lithium carbonate (Patent Document 4), and mortar containing Portland cement, calcium aluminate, anhydrous gypsum, lithium carbonate, and slaked lime have also been proposed (Patent Document 5). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 03-12350 [Patent Document 2] Japanese Patent Application Publication No. 01-230455 [Patent Document 3] Japanese Patent Application Publication No. 11-139859 [Patent Document 4] Japanese Patent Application Publication No. 01-290543 [Patent Document 5] Japanese Patent Publication No. 2005-75712 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the conventional materials mentioned above do not take long-term expansion into account, and after being applied to structures as grout, excessive expansion over a long period of time can occur, potentially damaging the structures. Therefore, there is a need for mortar materials for grout that take into account expansion performance from the initial stage to the long term.

[0008] Based on the above, the present invention aims to provide an ultra-fast-setting mortar material for grout that can achieve an appropriate long-term expansion rate. [Means for solving the problem]

[0009] The inventors of the present invention conducted intensive research to solve the above-mentioned problems and found that these problems can be solved by a super-fast-setting mortar material for grouting that contains cement, calcium aluminate, and gypsum, and is adjusted so that the initial expansion rate is within a predetermined range. This led to the present invention. In other words, the present invention is as follows.

[0010] [1] A super high early strength mortar material for grouting, comprising cement, calcium aluminate, and gypsum, and having expansion rates at 3 days, 7 days, and 28 days of age of 0.005 - 0.5%, 0.01 - 0.75%, and 0.015 - 1.0% respectively. [2] The super high early strength mortar material for grouting according to [1] above, wherein the air content after mixing is 0 - 5%. [3] The super high early strength mortar material for grouting according to [1] or [2] above, wherein the flow value after mixing is 170 - 320 mm. [4] After mixing, J

[0012] The super high early strength mortar material for grouting according to any one of [1] - [3] above, wherein the flow time of the J - funnel is 6 - 10 seconds. [5] The super high early strength mortar material for grouting according to any one of [1] - [4] above, further comprising a foaming agent. [6] The super high early strength mortar material for grouting according to any one of [1] - [5] above, further comprising an antifoaming agent. [7] The super high early strength mortar material for grouting according to any one of [1] - [6] above, further comprising one or more water - reducing agents selected from the group consisting of lignin - based water - reducing agents, melamine - based water - reducing agents, and naphthalene sulfonate - based water - reducing agents. [8] A mortar hardened body using the super high early strength mortar material for grouting according to any one of [1] - [7] above. [Advantages of the Invention]

[0011] According to the present invention, it is possible to provide a super high early strength mortar material for grouting that can moderate the long - term expansion rate. [Embodiments for Carrying out the Invention]

[0012] Hereinafter, an embodiment of the present invention (this embodiment) will be described in detail, but the present invention is not limited to this embodiment. In this specification, “%” and “parts” are based on mass unless otherwise specified.

[0013] [Super High Early Strength Mortar Material for Grouting] The ultra-high early strength mortar material for grouting of the present invention contains cement, calcium aluminate, and gypsum, and is an ultra-high early strength mortar material for grouting with expansion rates at 3 days, 7 days, and 28 days of age being 0.005 to 0.5%, 0.01 to 0.75%, and 0.015 to 1.0% respectively. It is preferable that the expansion rate satisfies the relationship: expansion rate at 3 days of age ≤ expansion rate at 7 days of age ≤ expansion rate at 28 days of age. The ultra-high early strength mortar material for grouting can be used as grout by mixing with water, and by adjusting the initial expansion rate to be within a predetermined range, the long-term expansion rate can be made appropriate. Thereby, when used as grout for a structure or the like, damage to the structure or the like can be prevented. Note that "long-term" refers to at least 60 days or more of age. Also, the expansion rate in the present invention is measured by a measurement method in accordance with the method specified in Appendix A, "Test Method for Expansion of Expansive Agents by Mortar", of JIS A 6202:2017, "Expansive Agents for Concrete".

[0014] The ultra-high early strength mortar material for grouting has an expansion rate at 3 days of age of 0.005 to 0.5%, preferably 0.01 to 0.4%, more preferably 0.05 to 0.3%, and even more preferably 0.1 to 0.2%. If the expansion rate at 3 days of age is less than 0.005%, there is a risk that the long-term expansion rate will be insufficient, and if it exceeds 0.5%, there is a risk that the long-term expansion rate will be excessive.

[0015] The ultra-high early strength mortar material for grouting has an expansion rate at 7 days of age of 0.01 to 0.75%, preferably 0.02 to 0.5%, more preferably 0.08 to 0.4%, and even more preferably 0.12 to 0.3%. If the expansion rate at 7 days of age is less than 0.01%, there is a risk that the long-term expansion rate will be insufficient, and if it exceeds 0.75%, there is a risk that the long-term expansion rate will be excessive.

[0016] The ultra-fast-setting mortar material for grouting has an expansion rate of 0.015 to 1.0% at 28 days of age, preferably 0.03 to 0.6%, more preferably 0.1 to 0.5%, and even more preferably 0.16 to 0.4%. If the expansion rate at 28 days of age is less than 0.015%, the long-term expansion rate may be insufficient, and if it exceeds 3.5%, the long-term expansion rate may be excessive.

[0017] The ultra-fast-setting mortar material for grout preferably has an air content of 0-5% after mixing, more preferably 0-4%, and even more preferably 0-3%. When the air content after mixing is within the above range, the strength development is improved. The air content in this invention was measured in accordance with the method specified in JIS A 1116:2019 "Test method for unit volume mass of fresh concrete and test method for air content by mass (mass method)".

[0018] The ultra-fast-setting mortar material for grouting preferably has a flow value of 170 to 320 mm after mixing, more preferably 190 to 250 mm, and even more preferably 200 to 220 mm. When the flow value after mixing is within the above range, the filling performance is improved. The flow value in this invention was measured using the method specified in JIS R 5201:2015 "Physical Testing Methods for Cement" without performing 15 drop tests.

[0019] The ultra-fast-setting mortar material for grouting is J after mixing. 14 The funnel flow time is preferably 6 to 10 seconds, more preferably 7 to 9 seconds, and even more preferably 7.5 to 8.5 seconds. 14 When the funnel flow time is within the above range, the filling performance improves. 14 The funnel flow time was measured in accordance with the method specified in the Japan Society of Civil Engineers standard JSCE-F 541-2013, "Test Method for Flowability of Filling Mortar."

[0020] The cement contained in the ultra-fast-setting mortar material for grout according to this embodiment is not particularly limited and includes various types of Portland cement such as ordinary, rapid-hardening, ultra-rapid-hardening, low-heat, and moderate-heat cements; various blended cements obtained by mixing these Portland cements with blast furnace slag, fly ash, silica fume, etc.; environmentally friendly cements (eco-cements) manufactured using municipal solid waste incineration ash, sewage sludge incineration ash, etc. as raw materials; commercially available fine-particle cements; white cements, etc. It is also possible to use various types of cement after they have been finely powdered. Furthermore, cements that have been adjusted by increasing or decreasing the content of components normally used in cement can also be used. In addition, combinations of two or more of these can also be used.

[0021] From the viewpoint of achieving appropriate fluidity and initial strength, cement should have a Blaine specific surface area value (hereinafter also simply referred to as "Blaine value") of 2,500 to 7,000 cm². 2 It is preferable that the amount is / g, and the range is 2,750 to 6,000 cm³. 2 It is more preferable that the amount is / g, and the range is 3,000 to 4,500 cm 2 It is even more preferable that the value is / g. In this invention, the Blaine specific surface area value was measured in accordance with JIS R 5201:2015 "Physical Testing Methods for Cement".

[0022] The calcium aluminate contained in the ultrafast-setting mortar material for grout according to this embodiment is a general term for compounds that have hydration activity and are mainly composed of CaO and Al2O3. It is a compound in which a portion of CaO and / or Al2O3 is substituted with alkali metal oxides, alkaline earth metal oxides, silicon dioxide, titanium dioxide, iron oxide, alkali metal halides, alkaline earth metal halides, alkali metal sulfates, and alkaline earth metal sulfates, or a substance in which a small amount of these is solid-dissolved in a substance mainly composed of CaO and Al2O3. The calcium aluminate may be crystalline or amorphous.

[0023] As a specific example of a crystalline material, if we consider CaO as C, Al2O3 as A, and R2O (Na2O, K2O, Li2O) as R, then C3A and C3A with alkali metals in solid solution are examples.14 RA5, CA, C 12 A7 or C 11 Examples include A7·CaF2, C4A·Fe2O3, and C3A3·CaSO4. However, amorphous calcium aluminate is preferred because of its good quick-setting property. In the case of amorphous calcium aluminate, the vitrification rate is preferably 80% or more.

[0024] The CaO / Al2O3 molar ratio of calcium aluminate is not particularly limited. From the perspective of maintaining fluidity and appropriate initial strength, the molar ratio is preferably 1.3 - 3.0, and more preferably 1.5 - 2.0.

[0025] As a method for obtaining calcium aluminate, heat treatment of a CaO raw material such as calcium carbonate or calcium hydroxide and an Al2O3 raw material such as bauxite in a rotary kiln or an electric furnace can be mentioned. Specifically, examples include mixing each raw material in a predetermined ratio, heating and melting using an electric furnace, etc., and then rapidly cooling by contacting with compressed air or water. By adjusting the ratio of each raw material, the above-mentioned CaO / Al2O3 molar ratio can be adjusted, and the vitrification rate can be adjusted by the temperature during heating and melting and the cooling method.

[0026] When obtaining calcium aluminate industrially, impurities may be contained. Specific examples include, for example, SiO2, Fe2O3, MgO, TiO2, MnO, Na2O, K2O, Li2O, S, P2O5, and F, etc. However, the presence of these impurities does not pose a particular problem as long as it does not substantially impede the object of the present invention. Specifically, there is no particular problem as long as the total of these impurities is 10% or less.

[0027] It is preferable to use calcium aluminate with an ignition loss of 1% or more, as specified in JIS R 5202:2015 "Methods for Chemical Analysis of Cement," and more preferably calcium aluminate with an ignition loss of 2% or more. An ignition loss of 1% or more in calcium aluminate helps to suppress the occurrence of "spotting." There are no particular limitations on the method for achieving an ignition loss of 1% or more, but examples include methods of supplying moisture or humidity, or supplying carbon dioxide.

[0028] The Brain value of calcium aluminate is not particularly limited, but is typically 3,000 to 9,000 cm². 2 A value of / g is preferred, and the range is 4,000 to 8,000 cm². 2 / g is preferable.

[0029] The calcium aluminate content of the ultrafast-setting mortar material for grouting is preferably 2 to 30 parts by mass, and more preferably 5 to 20 parts by mass, per 100 parts by mass of cement in the mortar material, from the viewpoint of adjusting the expansion rate at 3, 7, and 28 days of age.

[0030] The gypsum contained in the ultrafast-setting mortar material for grout according to this embodiment is a general term for anhydrous gypsum, hemihydrate gypsum, or dihydrate gypsum, and is not particularly limited, but from the viewpoint of strength development, the use of anhydrous gypsum or hemihydrate gypsum is preferred, and the use of anhydrous gypsum is more preferred.

[0031] The Blaine value of gypsum is not particularly limited, but is typically 3,000 to 9,000 cm³. 2 A value of / g is preferred, and the range is 4,000 to 8,000 cm². 2 / g is preferable.

[0032] The gypsum content of the ultrafast-setting mortar material for grouting is preferably 3 to 40 parts by mass, and more preferably 5 to 30 parts by mass, per 100 parts by mass of cement in the mortar material, from the viewpoint of adjusting the expansion rate at 3, 7, and 28 days of age.

[0033] The ultrafast-setting mortar material for grouting preferably further contains a foaming agent. The type of foaming agent can be an organic foaming agent, an inorganic foaming agent, or a foaming agent combining these. Examples of organic foaming agents include oily substances such as vegetable oils and mineral oils, and nitrogen gas foaming materials that foam nitrogen gas under an alkaline atmosphere, such as azo compounds, nitroso compounds, and hydrazine derivatives. Examples of inorganic foaming agents include percarbonates such as sodium percarbonate, potassium percarbonate, and ammonium percarbonate, permanganates such as potassium permanganate, peroxides such as hydrogen peroxide, and powders such as aluminum powder produced by the atomization method. Other foaming agents include flaky aluminum powder surface-treated with stearic acid.

[0034] The foaming agent content is preferably 0.002 to 0.5 parts by mass, more preferably 0.005 to 0.45 parts by mass, and even more preferably 0.008 to 0.4 parts by mass, per 100 parts by mass of cement in the ultra-fast-setting mortar material for grouting.

[0035] The ultrafast-setting mortar material for grouting preferably further contains an antifoaming agent. The type of antifoaming agent is not particularly limited as long as it does not significantly adversely affect the properties of the grout, and can be used in either liquid or powder form. Examples include polyether-based antifoaming agents, polyhydric alcohol-based antifoaming agents such as esterified polyhydric alcohols or alkyl ethers, alkyl phosphate-based antifoaming agents, and silicone-based antifoaming agents.

[0036] The amount of defoaming agent contained in the ultra-fast-setting mortar material for grout is preferably 0.002 to 0.5 parts by mass, more preferably 0.005 to 0.45 parts by mass, and even more preferably 0.01 to 0.4 parts by mass, per 100 parts by mass of cement. Having the defoaming agent contained within the above range improves strength development.

[0037] The ultra-fast-setting mortar material for grouting preferably further contains one or more water-reducing agents selected from the group consisting of lignin-based water-reducing agents, melamine-based water-reducing agents, and naphthalene sulfone-based water-reducing agents, and more preferably contains three types: lignin-based water-reducing agents, melamine-based water-reducing agents, and naphthalene sulfone-based water-reducing agents. Examples of lignin-based water-reducing agents include Kao Corporation's product name "Mighty 150" and Nippon Sika Corporation's product name "Plastcrete NC". Examples of melamine-based water-reducing agents include Nippon Sika Corporation's product name "Sikament FF24" and BASF Pozzoliths' product name "Master Reobuild 4000". Examples of naphthalene sulfone-based water-reducing agents include Kao Corporation's product name "Mighty 100", Sanyo Chemical Industries' product name "Sanyo Revelon PHL", and Daiichi Kogyo Seiyaku Co., Ltd.'s product name "Cellflow".

[0038] The water-reducing agent content is preferably 0.05 to 2.0 parts by mass, more preferably 0.1 to 1.8 parts by mass, and even more preferably 0.15 to 1.0 parts by mass, based on solid content, per 100 parts by mass of cement in the ultra-fast-setting mortar material for grouting. Having the water-reducing agent content within the above range improves filling properties.

[0039] The total content of cement, calcium aluminate, gypsum, foaming agent, defoaming agent, and water-reducing agent, excluding aggregate, in the ultra-fast-setting mortar material for grouting is preferably 90% or more, and more preferably 95% or more. This makes it easier to maintain a moderate long-term expansion rate.

[0040] The aggregates used in this invention can be the same fine aggregates and coarse aggregates used in ordinary cement mortar and concrete. Specifically, river sand, river gravel, mountain sand, mountain gravel, crushed stone, crushed sand, limestone aggregate, lime sand, silica sand, colored sand, artificial aggregate, blast furnace slag aggregate, sea sand, sea gravel, artificial lightweight aggregate, and heavy aggregate can be used, and these can also be combined.

[0041] The aggregate content is preferably 40 to 250 parts by mass, more preferably 50 to 230 parts by mass, and even more preferably 60 to 200 parts by mass, per 100 parts by mass of cement in the ultra-fast-setting mortar material for grouting. Having the aggregate content within the above range improves strength development and facilitates moderate long-term expansion.

[0042] In this invention, the fluidity retention effect can be enhanced and strength development further improved by using alkali metal carbonates. Examples of alkali metal carbonates include sodium carbonate, potassium carbonate, lithium carbonate, sodium bicarbonate, potassium bicarbonate, and lithium bicarbonate, and combinations of these are also possible. In particular, the use of lithium carbonate is preferred from the viewpoint of strength development.

[0043] The alkali metal carbonate content is preferably 1 to 6 parts by mass, and more preferably 2 to 5 parts by mass, per 100 parts by mass of cement in the ultra-fast-setting mortar material for grouting. Having the alkali metal carbonate content within this range makes it easier to ensure a consistent handling time and improves strength development.

[0044] The ultra-fast-setting mortar material for grout of the present invention can contain silicate fine powder from the viewpoint of enhancing strength development. Examples of silicate fine powder include latent hydraulic substances such as blast furnace granulated slag fine powder, fly ash, and pozzolanic substances such as silica fume, among which silica fume is preferred. The type of silica fume is not limited, but from the viewpoint of fluidity, the use of silica fume containing 10% or less of ZrO2 as an impurity, or acidic silica fume, is more preferred. Acidic silica fume refers to silica fume in which the pH of the supernatant liquid when 1 g of silica fume is added to 100 cc of pure water and stirred exhibits acidity of 5.0 or less.

[0045] The fineness of silica-based fine powder is not particularly limited, but typically, blast furnace granulated slag powder and fly ash have a Blaine value of 3,000 to 9,000 cm³. 2 The silica fume is in the range of / g, with a BET specific surface area of ​​20,000 to 300,000 cm². 2 It is within the range of / g.

[0046] The content of silica fine powder is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, and even more preferably 3 to 12 parts by mass, per 100 parts by mass of cement in the ultra-fast-setting mortar material for grouting. Having the silica fine powder content within the above range enhances the strength development.

[0047] In the present invention, a setting retarder may also be used. Preferably, the setting retarder is an oxycarboxylic acid or a salt thereof, with gluconic acid being more preferred as the oxycarboxylic acid, and sodium salt being more preferred as the salt.

[0048] The proportion of the setting retarder is preferably 0.3 to 6 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of cement in the ultra-fast-setting mortar material for grouting.

[0049] In the present invention, one or more of the following can be used, within a range that does not adversely affect performance: gas foaming substances, water-reducing agents, coagulation regulators, air-entraining agents, rust inhibitors, water-repellent agents, antibacterial agents, colorants, antifreeze agents, admixtures such as limestone fine powder, blast furnace slow-cooling slag fine powder, sewage sludge incineration ash and its molten slag, municipal solid waste incineration ash and its molten slag, and pulp sludge incineration ash, as thickeners, shrinkage reducing agents, polymers, clay minerals such as bentonite and sepiolite, and anion exchangers such as hydrotalcite, within a range that does not substantially hinder the objective of the present invention.

[0050] In the ultra-fast-setting mortar material for grout of the present invention, the method of mixing each material is not particularly limited. The materials may be mixed at the time of construction, or some or all of them may be mixed in advance. Any existing mixing device can be used, such as a tilting drum mixer, omni mixer, Henschel mixer, V-type mixer, Proscher mixer, and Nauta mixer.

[0051] [Hardened mortar] The hardened mortar of the present invention contains the ultra-fast hardening mortar material for grout of the present invention described above and water, and is formed by mixing the ultra-fast hardening mortar material for grout and water. The amount of mixing water in the present invention is not particularly limited as it varies depending on the purpose and use and the content ratio of each material, but it 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 cement material. When the amount of mixing water is within the above range, the filling properties and strength development are improved.

[0052] The construction methods using the ultra-fast-setting mortar material for grout of the present invention include methods of adding a predetermined amount of water, mixing it, and pouring it into the construction area; filling the area with the mixed grout using a pump; spraying the mixture after mixing it and then blowing compressed air into it; and applying it with a trowel. The mixing method is not particularly limited and includes methods of putting the material into a container such as a pail and mixing it with a hand mixer; mixing it using a mixer or the like; and mixing it by hand. The cement composition of the present invention hardens when mixed and filled into the construction area. That is, a hardened body made using the ultra-fast-setting mortar material for grout of the present invention is obtained. [Examples]

[0053] The present invention will be further described below based on experimental examples, but the present invention is not limited thereto.

[0054] <Experimental Example 1> A super-fast-setting mortar material for grouting was prepared by mixing the materials listed below with 100 parts by mass of cement in the proportions shown in Table 1. Aggregates and setting regulators were added in amounts of 100 parts by mass and 1.5 parts by mass, respectively, per 100 parts by mass of cement, calcium aluminate, and gypsum. Grout was prepared by adding 18 parts by mass of water to 100 parts by mass of the prepared super-fast-setting mortar material and mixing, and various measurements were performed. Furthermore, a hardened mortar body was manufactured using the prepared grout, and its strength was measured.

[0055] (Materials used) Cement: A trial cement based on ordinary Portland cement (various commercially available pure chemicals were used to adjust the raw materials and chemical components of the cement factory's mixture), Blaine value 3,450 cm². 2 / g. Calcium aluminate: Vitrification rate 97%, CaO / Al2O3 molar ratio 1.7, ignition loss 1.0%, main components CaO·Al2O3 and 12CaO·7Al2O3, Blaine value 5,000 cm² 2 / g. Gypsum: Anhydrous gypsum, reagent. Aggregate: A mixture of fine aggregate and lime sand (50% 0.6 mm or smaller, 50% 0.6-1.2 mm) was used. Density: 2.52 g / cm³ 3 . Antifoaming agent: A mixture of special nonionic surfactant and silica; commercially available. Foaming agent: Aluminum powder (surface-treated), commercially available product. Water-reducing agent 1: Naphthalene sulfonic acid-based water-reducing agent, commercially available product. Coagulation regulator: Sodium gluconate, reagent. Water: Tap water.

[0056] (Measurement items) Expansion Rate: The expansion rate of the grout after mixing was measured at 3, 7, 28, and 60 days of age, according to the measurement method specified in JIS A 6202:2017 "Expanding Agents for Concrete," Annex A "Test Method for Expansion of Expansing Agents by Mortar." The results are shown in Table 1. Air content: The air content of the grout after mixing was measured in accordance with the method specified in JIS A 1116:2019 "Test method for unit volume mass of fresh concrete and test method for air content by mass (mass method)". The results are shown in Table 1. Flow value: For the grout after mixing, the flow value was measured without performing 15 drop tests, according to the method specified in JIS R 5201:2015 "Physical Testing Methods for Cement". The results are shown in Table 1. J 14 Funnel flow time: For the grout after mixing, the flow time was measured in accordance with the method specified in the Japan Society of Civil Engineers standard JSCE-F 541-2013 "Test method for fluidity of filling mortar". The results are shown in Table 1. Expansion and contraction rates: The expansion and contraction rates of the grout after mixing were measured in accordance with the method specified in JSCE-F 542-2013 "Test method for bleeding rate and expansion rate of filling mortar". The results are shown in Table 1. Compressive Strength: The compressive strength of the hardened mortar was measured at 3 hours and 28 days of age in accordance with the method specified in JSCE-G 505-2018, "Test Method for Compressive Strength of Mortar or Cement Paste Using Cylindrical Specimens." The results are shown in Table 1.

[0057] [Table 1]

[0058] <Experimental Example 2> Grout was prepared and a hardened mortar body was manufactured in the same manner as in Experimental Example 1, except that the water-reducing agent shown below was also used.

[0059] (Materials used) Water-reducing agent 2: Lignin-based water-reducing agent, commercially available product. Water-reducing agent 3: Melamine-based water-reducing agent, commercially available product. [Table 2] [Industrial applicability]

[0060] The ultra-fast-setting mortar material for grouting of the present invention contains cement, calcium aluminate, and gypsum, and its initial expansion rate is within a predetermined range, allowing for an appropriate long-term expansion rate. Therefore, it can be widely applied in civil engineering and construction fields, such as anchoring to reinforcing bars in concrete structures used in water supply and drainage, agriculture and fisheries, railways, power plants, roads, and buildings.

Claims

1. Cement and calcium aluminate (however, C １１ A ７ CaF ２ (excluding) and gypsum, The CaO / Al of the aforementioned calcium aluminate ２ O ３ The molar ratio is 1.5 to 3.

0. The vitrification rate of the calcium aluminate is 80% or more. An ultra-fast-setting mortar material for grouting, with expansion rates of 0.005-0.5%, 0.01-0.75%, and 0.015-1.0% at 3, 7, and 28 days of age, respectively.

2. The ultra-fast-setting mortar material for grout according to claim 1, wherein the amount of air after mixing is 0-5%.

3. An ultrafast-setting mortar material for grout according to claim 1 or 2, wherein the flow value after mixing is 190 to 220 mm.

4. J after mixing １４ The ultra-fast-setting mortar material for grout according to claim 1 or 2, wherein the funnel flow time is 6 to 10 seconds.

5. The ultrafast-setting mortar material for grout according to claim 1 or 2, further comprising a foaming agent.

6. The ultrafast-setting mortar material for grout according to claim 1 or 2, further comprising an antifoaming agent.

7. The ultrafast-setting mortar material for grout according to claim 1 or 2, further comprising one or more water-reducing agents selected from the group consisting of lignin-based water-reducing agents, melamine-based water-reducing agents, and naphthalene sulfone-based water-reducing agents.

8. A hardened mortar body made using the ultrafast-setting mortar material for grout according to claim 1 or 2.

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