JP7394194B2 - grout mortar - Google Patents

Description

The present invention relates to a grout mortar composition, a grout mortar, a concrete structure, and a method for manufacturing the same.

Grout is used when constructing, repairing and reinforcing civil engineering structures, building structures, etc., or when installing machinery. When construction time is limited, such as when performing partial repair work on structures such as roads and railways, it is desirable to use materials that quickly develop strength after construction. In addition, in recent years, grouts have been required not only to develop strength quickly but also to have high strength.

For example, as a high-strength grout, Patent Document 1 states that it contains cement, 2 to 20% by mass of amorphous aluminosilicate mineral powder, and 3 to 18% by mass of gypsum, and is used at a water binder ratio of 26 to 35%. An ultra-high strength grout composition is disclosed.

Japanese Patent Application Publication No. 2011-136863

By the way, depending on the construction location and construction conditions, in addition to characteristics such as good strength development, grout is required to have quick hardening properties, no sag or movement on slopes, etc., and fluidity similar to mortar that is easy to apply. . However, it has been difficult to prepare materials that have both of these properties.

Therefore, it is an object of the present invention to provide a grout mortar composition and grout mortar that maintain appropriate fluidity and have excellent fast hardening and strength development, as well as a concrete structure using the grout mortar and a method for manufacturing the same. purpose.

As a result of intensive studies regarding the above-mentioned issues, the present inventors have developed a grout that maintains fluidity and has excellent quick hardening and strength development properties by adjusting the content and blending ratio of antifoaming agents and thickeners. It has been found that a mortar composition can be obtained.

That is, the present invention is shown in [1] to [9] below.
[1] Contains a binder made of cement, calcium aluminates, and gypsum, fine aggregate, an antifoaming agent, and a thickener, and the total content of the antifoaming agent and the thickening agent is: The amount is 0.03 to 1.0 parts by mass relative to 100 parts by mass of the binder, and the mass ratio of the antifoaming agent to the thickening agent ([mass of antifoaming agent]/[mass of thickening agent]) is from 0.5 to 9.
[2] The grout mortar composition according to [1], wherein the content of the fine aggregate is 30 to 250 parts by mass based on 100 parts by mass of the binder.
[3] The grout mortar composition according to [1] or [2], further comprising an alkali metal carbonate.
[4] The grout mortar composition according to any one of [1] to [3], wherein the mass ratio of the cement to the total mass of the binder is 60 to 95% by mass.
[5] The grout mortar composition according to any one of [1] to [4], which is used for repairing floor slabs or reinforcing floor slabs.
[6] Contains the grout mortar composition according to any one of [1] to [5] and water, and the content of the water is 22 to 40 parts by mass based on 100 parts by mass of the binder. , grout mortar.
[7] On the concrete slab, from the concrete slab side, a grout mortar layer made of a hardened grout mortar according to [6], a waterproof layer made of a hardened thermosetting resin, and asphalt or concrete. A concrete structure consisting of a surface layer and a surface layer, which are laminated in this order.
[8] The concrete structure according to [7], wherein the thermosetting resin is an epoxy resin or a urethane resin.
[9] A step of casting the grout mortar according to [6] on a concrete slab to form a grout mortar layer, and applying a thermosetting resin on the grout mortar layer before the completion time of the grout mortar. A method for manufacturing a concrete structure, comprising the steps of: coating and curing to form a waterproof layer made of a cured body of the thermosetting resin; and forming a surface layer made of asphalt or concrete on the waterproof layer.

According to the present invention, it is possible to provide a grout mortar composition and grout mortar that maintain appropriate fluidity and have excellent fast hardening and strength development, as well as a concrete structure using the grout mortar and a method for manufacturing the same. can.

1 is a side sectional view schematically showing an embodiment of a concrete structure of the present invention.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited thereto.

[Grout mortar composition]
The grout mortar composition of this embodiment includes a binder made of cement, calcium aluminates, and gypsum, fine aggregate, an antifoaming agent, and a thickener.

In the grout mortar composition of this embodiment, the binder is composed of three components: cement, calcium aluminates, and gypsum.

Various types of cement can be used, such as ordinary, early-strength, ultra-early-strength, low-heat, and medium-heat Portland cements, and various types of Portland cements mixed with blast furnace slag, fly ash, or silica. Examples include mixed cement, filler cement mixed with slowly cooled blast furnace slag powder such as limestone powder, and environmentally friendly cement (ecocement) manufactured using various industrial wastes as main raw materials. One type of cement may be used alone, or two or more types may be used in combination. From the viewpoint of easily ensuring fluidity, the cement is preferably ordinary Portland cement.

The mass proportion of cement is preferably 60 to 95% by mass, more preferably 60 to 90% by mass, and most preferably 70 to 85% by mass, based on the total mass of the binder.

Calcium aluminates include C ₃ A, C ₂ A, C ₁₂ A ₇ , CA when CaO is C, Al ₂ O ₃ is A, Na ₂ O is N, and Fe ₂ O ₃ is F. , or calcium aluminate with a mineral composition expressed as CA ₂ , etc., calcium aluminoferrite expressed as C ₄ AF, etc., C ₃ A ₃・CaF ₂ or C ₁₁ in which halogen is dissolved or substituted in calcium aluminate. Calcium haloaluminates, including calcium fluoroaluminates labeled as A _{7.CaF 2} , etc.; calcium sodium aluminates, calcium lithium aluminates, alumina cements, labeled as C ₈ NA ₃ , C ₃ N ₂ A ₅ , etc.; It is also a general term for calcium sulfoaluminates expressed as C ₃ A ₃ · CaSO ₄ etc. One type of calcium aluminate may be used alone, or two or more types may be used in combination.

As calcium aluminates, calcium aluminates obtained by rapidly cooling a heat-treated product having a CaO/Al ₂ O ₃ molar ratio of 1.0 to 1.8 are preferred from the viewpoint of superior reaction activity. When the molar ratio of CaO/Al ₂ O ₃ is within the above range, better fluidity and strength development are likely to be obtained.

Calcium aluminates preferably have a vitrification rate of 10% or more from the viewpoint of easily imparting sufficient quick hardening properties. The vitrification rate is calculated from the following formula.
Vitrification rate (%) = (1-(MC/MS)) x 100
For calcium aluminates whose mass is MS, the mass of each mineral contained in the calcium aluminates is determined by powder X-ray diffraction using an internal standard method, etc., and the total mass (MC) of the quantified mineral phases is calculated. The remainder is considered to be a pure glass phase.

The fineness of the calcium aluminates is preferably 3000 cm ² /g or more in Blaine specific surface area, more preferably 5000 cm ² /g or more, from the viewpoint of further improving initial strength development. The fineness of the calcium aluminates is preferably 5000 to 8000 cm ² /g in Blaine specific surface area.

The mass proportion of calcium aluminates is preferably 5 to 30 mass%, more preferably 6 to 25 mass%, based on the total mass of the binder, from the viewpoint of further improving rapid hardening. Most preferably it is between 7 and 15% by weight.

Examples of gypsum include anhydrite, hemihydrate gypsum, dihydrate gypsum, and the like. As the gypsum, anhydrite is preferable from the viewpoint of further improving strength development. One type of gypsum may be used alone, or two or more types may be used in combination.

From the viewpoint of further improving long-term strength development, the mass proportion of gypsum is preferably 2 to 15% by mass, more preferably 3 to 12% by mass, based on the total mass of the binder. Most preferably it is 5-10% by weight.

Examples of the fine aggregate include river sand, silica sand, crushed sand, kansui stone, limestone sand, and slag aggregate. Among these fine aggregates, it is preferable to use silica sand, limestone sand, etc. whose particle size has been adjusted to a particle size that does not contain fine powder or coarse aggregate. One type of fine aggregate may be used alone, or two or more types may be used in combination. As the fine aggregate, it is preferable to use a commonly used particle size of 5 mm or less (the amount that passes through a 5 mm sieve).

The particle size of the fine aggregate is not particularly limited, and can be adjusted within the required particle size range of the fine aggregate. The particle size of fine aggregate can be considered from the coarse particle ratio specified by JIS A 1102:2014 "Sieving test method for aggregate". From the viewpoint that better fluidity is easily obtained when made into mortar and bleeding is easily suppressed, the coarse particle ratio of the fine aggregate is preferably 1 to 4, and 1.5 to 3.8. More preferably, it is 2 to 3.5.

The content of the fine aggregate is preferably 30 to 250 parts by mass, more preferably 35 to 180 parts by mass, and even more preferably 45 to 150 parts by mass, based on 100 parts by mass of the binder. The amount is preferably 55 to 140 parts by weight, and most preferably 55 to 140 parts by weight. If the content of the fine aggregate is within the above range, better fluidity will be ensured and strength development in a short period of time will be even more excellent.

The antifoaming agent is not particularly limited as long as it is an antifoaming agent used in general concrete, and examples include mineral oil-based antifoaming agents, ester-based antifoaming agents, amine-based antifoaming agents, amide-based antifoaming agents, and polyamide-based antifoaming agents. Examples include ether defoaming agents and silicone defoaming agents. Among these, polyether antifoaming agents are preferred from the viewpoint of exhibiting better antifoaming effects. The antifoaming agent may be in the form of a liquid or a powder, but when it is used as a premix, it is preferably a powder.

The content of the antifoaming agent is preferably 0.02 to 0.6 parts by mass, more preferably 0.03 to 0.5 parts by mass, and 0.04 parts by mass based on 100 parts by mass of the binder. Most preferably, it is 0.35 parts by weight. If the content of the antifoaming agent is within the above range, connected air can be further reduced, and strength reduction caused by air connections can be easily prevented.

The type of thickener is not particularly limited, and examples thereof include cellulose thickeners, acrylic thickeners, guar gum thickeners, and the like. As the thickener, cellulose-based thickeners are preferred from the viewpoint of superior material separation resistance. Examples of cellulosic thickeners include carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose. One type of thickener may be used alone, or two or more types may be used in combination.

The content of the thickener is preferably 0.01 to 0.4 parts by mass, more preferably 0.01 to 0.2 parts by mass, and 0.01 parts by mass based on 100 parts by mass of the binder. Most preferably, it is 0.15 parts by weight. If the content of the thickener is within the above range, more appropriate fluidity can be easily ensured.

The total content of the antifoaming agent and thickener is 0.03 to 1.0 parts by mass based on 100 parts by mass of the binder. If the total content of the antifoaming agent and thickener is outside the above range, good fluidity and strength development cannot be ensured. From the viewpoint of obtaining more appropriate fluidity and higher strength development, the total content of the antifoaming agent and thickener is 0.04 to 0.7 parts by mass based on 100 parts by mass of the binder. The amount is preferably 0.05 to 0.4 parts by mass, and more preferably 0.05 to 0.4 parts by mass.

The mass ratio of antifoaming agent to thickener ([mass of antifoaming agent]/[mass of thickening agent]) is from 0.5 to 9. If the mass ratio of the antifoaming agent to the thickener is outside the above range, good fluidity and strength development cannot be ensured. From the viewpoint of obtaining more appropriate fluidity and higher strength development, the mass ratio of the antifoaming agent to the thickener is preferably 0.7 to 7, and preferably 0.5 to 5. More preferred.

The grout mortar composition of this embodiment may contain a peroxide substance. Examples of the peroxide substance include percarbonates such as sodium percarbonate, potassium percarbonate, and ammonium percarbonate. One type of peroxide substance may be used alone, or two or more types may be used in combination.

The content of the peroxide substance is preferably 0.03 to 0.2 parts by mass, more preferably 0.05 to 0.15 parts by mass, and 0.07 parts by mass based on 100 parts by mass of the binder. Most preferably ˜0.12 parts by weight. If the content of the peroxide substance is within the above range, sufficient initial expansion hardening is likely to be obtained and strength development is unlikely to decrease.

The grout mortar composition of this embodiment may also contain an alkali metal carbonate. The alkali metal carbonate is not particularly limited as long as it is a carbonate of an alkali metal (group 1 element of the periodic table excluding hydrogen atoms). As the alkali metal carbonate, lithium carbonate, sodium carbonate, and potassium carbonate are preferable from the viewpoint of further promoting strength development. One type of alkali metal carbonate may be used alone, or two or more types may be used in combination.

The content of the alkali metal carbonate is preferably 0.05 to 0.5 parts by mass, more preferably 0.1 to 0.4 parts by mass, and 0.05 to 0.5 parts by mass, more preferably 0.1 to 0.4 parts by mass, based on 100 parts by mass of the binder. Most preferably 15 to 0.3 parts by weight. When the content of the alkali metal carbonate is within the above range, appropriate fluidity can be easily obtained and initial coagulation can be easily promoted.

The grout mortar composition of this embodiment may also contain a water reducing agent. Water reducers include superplasticizers, super AE water reducers, AE water reducers, and superplasticizers. Examples of such water reducing agents include water reducing agents specified in JIS A 6204:2011 "Chemical admixtures for concrete". Examples of the water reducing agent include polycarboxylic acid water reducing agents, naphthalene sulfonic acid water reducing agents, lignin sulfonic acid water reducing agents, melamine water reducing agents, acrylic water reducing agents, and the like. Among these, polycarboxylic acid water reducing agents are preferred. One type of water reducing agent may be used alone, or two or more types may be used in combination.

The content of the water reducing agent is preferably 0.15 to 0.5 parts by mass, more preferably 0.2 to 0.4 parts by mass, and 0.2 to 0.4 parts by mass, based on 100 parts by mass of the binder. Most preferably, it is 0.3 parts by mass. If the content of the water reducing agent is within the above range, good fluidity is likely to be obtained when made into mortar, and strength development during curing is also likely to be improved.

The grout mortar composition of this embodiment may also contain a setting retarder. Examples of setting retarders include organic acids or salts thereof such as citric acid, gluconic acid, malic acid, and tartaric acid; borates such as boric acid and sodium borate, phosphates, alkali metal carbonates, and alkali metal heavy Examples include inorganic salts such as carbonates; sugars. Among these, citric acid, citrates, tartaric acid, tartrates and alkali metal carbonates are preferred. The setting retarder may be in the form of a powder or a liquid (eg, in the form of an aqueous solution, emulsion, or suspension). The setting retarder may be used alone or in combination of two or more.

The content of the setting retarder is preferably 0.05 to 0.7 parts by mass, more preferably 0.1 to 0.5 parts by mass, and 0.2 parts by mass based on 100 parts by mass of the binder. Most preferably, it is 0.4 parts by weight. If the content of the setting retarder is within the above range, it is easier to ensure a longer pot life, and the initial strength development is less likely to deteriorate.

The grout mortar composition of this embodiment may contain various admixtures (materials) to the extent that the effects of the present invention are not impaired. Examples of admixtures (materials) include swelling agents, foaming agents, waterproofing agents, rust preventives, shrinkage reducing agents, water retention agents, pigments, water repellents, anti-efflorescence agents, fibers, and the like.

The grout mortar composition of this embodiment can be prepared by mixing the above-mentioned components using a commonly used kneading device, and the device is not particularly limited. Examples of the kneading device include a hand mixer, a tilting mixer, a pan-type mixer, and a biaxial mixer.

[Grout mortar]
The grout mortar composition of this embodiment can be mixed with water to prepare a grout mortar, and the water content may be adjusted as appropriate depending on the application. The water content is preferably 22 to 40 parts by weight, more preferably 23 to 37 parts by weight, and most preferably 25 to 34 parts by weight based on 100 parts by weight of the binder. If the water content is within the above range, it will be easier to ensure fluidity when made into mortar, further suppress drying shrinkage during curing, and provide even better strength development.

The grout mortar of this embodiment conforms to JIS R 5201:2015 "Physical test method for cement" 12. The flow value (0 stroke) measured in a 20°C environment according to the flow test is preferably 150 to 220 mm, more preferably 155 to 210 mm, and most preferably 160 to 200 mm. If the flow value (0 stroke) of the grout mortar is within the above range, the mortar will be easy to prepare and will not sag even when tilted.

The grout mortar of this embodiment can be prepared by mixing the above-mentioned components using a commonly used kneading device, and the device is not particularly limited. Examples of the kneading device include a hand mixer, a tilting mixer, a pan-type mixer, and a two-shaft mixer.

The grout mortar composition and grout mortar of the present embodiment have excellent rapid hardening properties and strength development while ensuring appropriate fluidity. Therefore, such a grout mortar composition and grout mortar can be used, for example, as a repair/reinforcement material for concrete structures, road slabs, and the like.

[Concrete structure]
The concrete structure of this embodiment will be described in detail with reference to the drawings. For convenience of drawing, the dimensional proportions in the drawings do not necessarily correspond to those in the description.

FIG. 1 is a side sectional view schematically showing one embodiment of the concrete structure of the present invention.
The concrete structure 10 according to the present embodiment includes a grout mortar layer 2 made of a hardened grout mortar and a waterproof layer 3 made of a hardened thermosetting resin on a concrete slab 1 from the concrete deck 1 side. and a surface layer 4 made of asphalt or concrete are laminated in this order.

The concrete floor slab 1 is not particularly limited, and examples thereof include a concrete floor slab, a concrete floor slab partially repaired with polymer cement, and the like.

The grout mortar layer 2 is made by hardening the grout mortar of this embodiment described above. The thickness of the grout mortar layer 2 is preferably from 5 to 50 mm, more preferably from 10 to 40 mm, and from 12 to 30 mm, from the viewpoint of being cost-effective and providing sufficient repair and reinforcing effects. Most preferably.

The waterproof layer 3 is made of hardened thermosetting resin. In the concrete structure 10, since the waterproof layer 3 is formed on the grout mortar layer 2, it is possible to further prevent water from entering the concrete slab 1. Examples of the thermosetting resin include epoxy resin, urethane resin, and unsaturated polyester resin. The thermosetting resin is preferably an epoxy resin or a urethane resin from the viewpoint of superior waterproof properties. The thickness of the waterproof layer is not particularly limited as long as it provides a sufficient waterproof effect.

The surface layer 4 is made of asphalt or concrete. The asphalt and concrete used to form the surface layer 4 are not particularly limited, and any commonly used asphalt may be used. The thickness of the surface layer 4 is preferably 50 to 100 mm, more preferably 60 to 80 mm, from the viewpoint of further protecting the deck layer 1.

In addition, in the concrete structure 10 of the present embodiment, the concrete slab 1, the grout mortar layer 2, the waterproof layer 3, and the surface layer 4 may be laminated in this order from the concrete slab 1 side, and other layers may be excluded. It's not something you do. For example, the concrete structure 10 may further include a second waterproof layer formed of urethane resin or the like between the waterproof layer 3 and the surface layer 4.

[Manufacturing method of concrete structure]
The method for manufacturing a concrete structure according to the present embodiment includes a step of pouring the above-mentioned grout mortar onto a concrete slab 1 to form a grout mortar layer 2, and a step of depositing a thermosetting resin on the grout mortar layer 2. The method includes a step of coating and curing to form a waterproof layer 3 made of a cured thermosetting resin, and a step of forming a surface layer 4 made of asphalt or concrete on the waterproof layer 3. Each step will be explained below.

In the process of forming the grout mortar layer 2 on the concrete slab 1, the surface of the concrete slab 1 is coated with a water jet, Polishing by shot blasting, manual chiseling, etc. is preferable.

In the step of forming the waterproof layer 3 on the grout mortar layer 2, a thermosetting resin may be applied on the grout mortar layer 2 before the grout mortar termination time, and a thermosetting resin may be applied on the grout mortar layer 2 after the grout mortar termination time. A thermosetting resin may be applied to the surface. From the viewpoint of further suppressing cracking during hardening of the grout mortar constituting the grout mortar layer 2 and further improving waterproofness, it is preferable to apply the thermosetting resin before the end time of the grout mortar. In this specification, "completion time" refers to the time measured according to "JIS A 1147:2007 Concrete setting time test method". The coating amount of the thermosetting resin is preferably 250 to 750 g/m ² and more preferably 350 to 650 g/m ² from the viewpoint that it can be applied just the right amount per 1 m ² and is even more effective. It is preferably 400 to 600 g/m ² .

A thermosetting resin composition obtained by adding known additives such as a curing agent, a curing accelerator, and a solvent to the above-mentioned thermosetting resin may be used to form the waterproof layer 3. The viscosity of the thermosetting resin composition is preferably 200 Pa·s or less, more preferably 100 Pa·s or less, from the viewpoint of easy application and further excellent workability.

In the step of forming the surface layer 4 on the waterproof layer 3, the surface layer 4 may be formed by spreading asphalt or pouring concrete on the waterproof layer 3 according to a known method.

The concrete structure of this embodiment has extremely high durability because the concrete slab is repaired or reinforced with the above-mentioned hardened grout mortar, and the hardened grout mortar is also waterproofed with a waterproof layer. It is.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

The materials used in the examples are as follows.
Cement: Ordinary Portland cement (abbreviation C)
Calcium aluminates: Alumina cement (CaO/Al ₂ O ₃ molar ratio: 1.4, vitrification rate: 40%, Blaine specific surface area: 5000 cm ² /g, abbreviation CA)
Gypsum: Anhydrite (abbreviation CS)
Peroxide substance: Sodium percarbonate Alkali metal carbonate: Lithium carbonate Set retardant: Citric acid Water reducer: Polycarboxylic acid-based high-performance water reducer Antifoaming agent: Polyether-based antifoaming agent (abbreviation: Pe)
Thickener: Water-soluble cellulose (methyl cellulose, abbreviation Ce)
Fine aggregate: silica sand (coarse grain ratio: 2.70, abbreviation S)
Water: Water supply (abbreviation W)

[Blend design of grout mortar composition]
The amounts of various materials are shown in Table 1, and 0.1 part by mass of sodium percarbonate, 0.2 part by mass of lithium carbonate, and 100 parts by mass of a binder consisting of cement, calcium aluminates, and gypsum. The formulation was designed using 0.3 parts by mass of the acid and 0.25 parts by mass of the water reducing agent.

[Preparation of grout mortar]
In a 20° C. environment, the designed grout mortar composition and water were added to a 10 L cylindrical container, and mixed with a hand mixer for 120 seconds to prepare about 3 L of grout mortar.

[Evaluation method]
- Consistency JIS R 5201:2015 "Physical test method for cement" 12. According to the flow test, the flow value (0 stroke) of the grout mortar was measured in a 20°C environment, and this was evaluated as the consistency.
- Pot life: The starting time of the grout mortar was measured according to JIS A 1147:2007 "Concrete setting test method". The starting time was evaluated as the usable time, and those whose starting time was 30 minutes or more were evaluated as good (○), and those outside this range were evaluated as poor (x).
・Compressive strength In accordance with the Japan Society of Civil Engineers standard JSCE-G 505-2013 "Test method for compressive strength of mortar or cement paste using cylindrical specimens", compression at 2 hours and 28 days in a 20°C environment. The strength was measured. The dimensions of the specimen were 50 mm in diameter and 100 mm in height. As for the 28-day-old specimens, they were cured in a humid environment at 20°C until the formwork was removed at 2 hours of age, then immediately transferred to water at 20°C, and then cured in water at 20°C until immediately before testing. For specimens with an age of 2 hours, wet curing was performed at 20°C. If the compressive strength at 2 hours of material age is 15 N/mm ² or more, it can be said that the material has excellent rapid hardening properties.

1 concrete floor slab, 2 grout mortar layer, 3 waterproof layer, 4 surface layer, 10 concrete structure.

Claims (7)

Contains a binder made of cement, calcium aluminates and gypsum, fine aggregate, an antifoaming agent, a thickener, and water,
The cement is at least one selected from the group consisting of Portland cement, mixed cement, filler cement, and environmentally friendly cement,
The total content of the antifoaming agent and the thickening agent is 0.03 to 1.0 parts by mass based on 100 parts by mass of the binder,
The mass ratio of the antifoaming agent to the thickening agent ([mass of antifoaming agent]/[mass of thickening agent]) is 0.5 to 9,
The water content is 22 to 40 parts by mass based on 100 parts by mass of the binder,
JIS R 5201:2015 “Physical test method for cement” 12. A grout mortar with a flow value (0 stroke) of 150 to 220 mm measured in a 20°C environment according to a flow test. The grout mortar according to claim 1, wherein the content of the fine aggregate is 30 to 250 parts by mass based on 100 parts by mass of the binder. The grout mortar according to claim 1 or 2, further comprising an alkali metal carbonate. The grout mortar according to claim 3, wherein the alkali metal carbonate is lithium carbonate. The grout mortar according to any one of claims 1 to 4, wherein the mass proportion of the cement to the total mass of the binder is 60 to 95% by mass. The grout mortar according to any one of claims 1 to 5, which is used for repairing or reinforcing floor slabs. According to the Japan Society of Civil Engineers standard JSCE-G 505-2013 "Test method for compressive strength of mortar or cement paste using cylindrical specimens", the compressive strength at 28 days of material age is 76.5 N/mm ² in a 20°C environment. The grout mortar according to any one of claims 1 to 6, which is the above.