JP7166827B2 - Grout mortar composition, grout mortar, concrete structure and method for producing the same - Google Patents

Description

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

2. Description of the Related Art Grout is used when constructing or repairing civil engineering structures, building structures, etc., or when installing machines. When construction work is limited in time, such as partial repair work of structures such as roads and railways, it is desired to use materials that exhibit strength immediately after construction. Moreover, in recent years, in addition to early strength development, grout has also been required to have high strength.

For example, as a high-strength grout, in Patent Document 1, 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%. Disclosed is an ultra-high strength grout composition characterized by:

JP 2011-136863 A

By the way, depending on the construction site and construction conditions, in addition to the characteristics of good strength development, grout is required to be fast hardening, not to sag or move even on slopes, etc., and to have fluidity similar to mortar that is easy to work. . However, it has been difficult to prepare materials that combine these properties.

Therefore, the present invention aims to provide a grout mortar composition and grout mortar that are fast-hardening and excellent in strength development while maintaining appropriate fluidity, a concrete structure using the grout mortar, and a method for producing the same. aim.

As a result of intensive studies on the above problems, the present inventors have found that by adjusting the content and blending ratio of the antifoaming agent and the thickening agent, a grout that is excellent in rapid hardening and strength development while ensuring fluidity. It has been found that a mortar composition is obtained.

That is, the present invention is represented by the following [1] to [9].
[1] Contains a binder made of cement, calcium aluminates and gypsum, a fine aggregate, an antifoaming agent, and a thickening agent, and the total content of the antifoaming agent and the thickening agent is It is 0.03 to 1.0 parts by mass with respect 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 with respect to 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 for floor slab repair or floor slab reinforcement.
[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 with respect to 100 parts by mass of the binder , grout mortar.
[7] On the concrete floor slab, from the concrete floor slab side, a grout mortar layer made of the hardened grout mortar described in [6], a waterproof layer made of a hardened thermosetting resin, and asphalt or concrete A concrete structure in which a surface layer consisting of and is 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 placing the grout mortar according to [6] on a concrete floor 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: applying and curing to form a waterproof layer composed of a cured body of the thermosetting resin; and forming a surface layer composed of asphalt or concrete on the waterproof layer.

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to provide a grout mortar composition and grout mortar that are fast-hardening and excellent in strength development while maintaining appropriate fluidity, a concrete structure using the grout mortar, and a method for producing the same. can.

BRIEF DESCRIPTION OF THE DRAWINGS It is side sectional drawing which shows typically one Embodiment of the concrete structure of this invention.

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

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

In the grout mortar composition of the present embodiment, the binding material consists of three components: cement, calcium aluminates and gypsum.

Various cements can be used, for example, various Portland cements such as normal, high early strength, super early strength, low heat, moderate heat, 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 fine powder such as limestone powder, and environment-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. The cement is preferably ordinary Portland cement from the viewpoint of easy securing of fluidity.

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

As calcium aluminates, when CaO is C, Al ₂ O ₃ is A, Na ₂ O is N, and Fe ₂ O ₃ is F, C ₃ A, C ₂ A, C ₁₂ A ₇ , CA , or calcium aluminate having a mineral composition indicated as CA ₂ , etc., calcium aluminoferrite indicated 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} denoted as _A7.CaF2 , calcium sodium _aluminates denoted as _C8NA3 and _{C3N2A5 ,} calcium lithium aluminates, alumina cements; and calcium sulfoaluminate indicated as C ₃ A ₃ ·CaSO ₄ and the like. Calcium aluminates may be used singly or in combination of two or more.

As the calcium aluminates, calcium aluminates obtained by quenching a heat-treated product having a CaO/Al ₂ O ₃ molar ratio of 1.0 to 1.8 are preferable from the viewpoint of better reaction activity. When the CaO/Al ₂ O ₃ molar ratio 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 rapid hardening properties. The vitrification rate is calculated from the following formula.
Vitrification rate (%) = (1-(MC/MS)) x 100
In calcium aluminates whose mass is MS, the mass of each mineral contained in this calcium aluminate is quantified by powder X-ray diffraction by an internal standard method, etc., and the total mass (MC) of the quantified mineral phase is calculated. calculated and the remainder is considered as the pure glass phase.

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

The mass ratio of calcium aluminates is preferably 5 to 30% by mass, more preferably 6 to 25% by mass, with respect to the total mass of the binder, from the viewpoint of further improving rapid hardening properties. 7 to 15% by weight is most preferred.

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

The mass ratio of gypsum is preferably 2 to 15% by mass, more preferably 3 to 12% by mass, based on the total mass of the binder, from the viewpoint of further improving long-term strength development. 5 to 10% by weight is most preferred.

Examples of fine aggregates include river sand, silica sand, crushed sand, cold water stone, limestone sand, and slag aggregate. Among these fine aggregates, it is preferable to use silica sand, limestone sand, or the like adjusted to a particle size that does not contain fine powder or coarse aggregate. Fine aggregates may be used singly or in combination of two or more. It is preferable to use fine aggregate having a particle size of 5 mm or less (a portion passed through a 5 mm sieve), which is usually used.

The particle size of the fine aggregate is not particularly limited, and can be adjusted within the range of the required particle size of the fine aggregate. Fine aggregate can consider the particle size from the coarse particle rate prescribed|regulated by JIS A 1102:2014 "sieving test method of an aggregate". From the viewpoint that it is easy to obtain good fluidity when it is made into mortar and it is easy to suppress bleeding, the coarse particle ratio of the fine aggregate is preferably 1 to 4, and 1.5 to 3.8. is more preferred, and 2 to 3.5 is most preferred.

The content of 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 with respect to 100 parts by mass of the binder. It is preferably 55 to 140 parts by mass, and most preferably 55 to 140 parts by mass. If the content of the fine aggregate is within the above range, the strength development property in a short time is further improved while securing better fluidity.

The antifoaming agent is not particularly limited as long as it is an antifoaming agent used in general concrete. Ether antifoaming agents, silicone antifoaming agents and the like are included. Among these, polyether-based antifoaming agents are preferable from the viewpoint of exerting a more excellent antifoaming effect. The form of the antifoaming agent may be liquid or powder, but it is preferably powder when used as a premix.

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 with respect to 100 parts by mass of the binder. Most preferably, it is ~0.35 parts by mass. If the content of the antifoaming agent is within the above range, the amount of connected air can be further reduced, and it is easy to prevent a decrease in strength caused by air connection.

The type of thickener is not particularly limited, and examples thereof include cellulose-based thickeners, acrylic thickeners, guar gum-based thickeners, and the like. As the thickener, a cellulose-based thickener is preferable from the viewpoint of being more excellent in material separation resistance. Cellulosic thickeners include, for example, carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose. A thickener may be used individually by 1 type, and may be used in combination of 2 or more types.

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, more preferably 0.01 part by mass with respect to 100 parts by mass of the binder. ~0.15 parts by weight is most preferred. If the content of the thickener is within the above range, it is easy to ensure more appropriate fluidity.

The total content of the antifoaming agent and thickening agent is 0.03 to 1.0 parts by mass with respect to 100 parts by mass of the binder. If the total content of the antifoaming agent and the thickening agent 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 the thickening agent is 0.04 to 0.7 parts by mass with respect to 100 parts by mass of the binder. is preferred, and 0.05 to 0.4 parts by mass is more preferred.

The mass ratio of antifoaming agent to thickening agent ([mass of antifoaming agent]/[mass of thickening agent]) is 0.5-9. If the mass ratio of the antifoaming agent to the thickening agent 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, more preferably 0.5 to 5. more preferred.

The grout mortar composition of this embodiment may contain a peroxide material. Examples of peroxides 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 is preferably 0.03 to 0.2 parts by mass, more preferably 0.05 to 0.15 parts by mass, more preferably 0.07 parts by mass, based on 100 parts by mass of the binder. ~0.12 parts by weight is most preferred. When the content of the peroxide is within the above range, sufficient initial expansion hardening is likely to be obtained, and strength development is less likely to decrease.

The grout mortar composition of this embodiment may contain an alkali metal carbonate. Alkali metal carbonates are not particularly limited as long as they are carbonates of alkali metals (group 1 elements 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 with respect to 100 parts by mass of the binder. 15 to 0.3 parts by mass is most preferred. When the content of the alkali metal carbonate is within the above range, appropriate fluidity is likely to be obtained, and initial coagulation is likely to be promoted.

The grout mortar composition of this embodiment may contain a water reducing agent. Water reducers include high performance water reducers, high performance AE water reducers, AE water reducers and superplasticizers. Such water reducing agents include those specified in JIS A 6204:2011 "Chemical Admixtures for Concrete". Examples of water reducing agents include polycarboxylic acid water reducing agents, naphthalenesulfonic acid water reducing agents, ligninsulfonic acid water reducing agents, melamine water reducing agents, and acrylic water reducing agents. Among these, polycarboxylic acid-based 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, more preferably 0.2 to 0.2 parts by mass with respect to 100 parts by mass of the binder. 0.3 parts by mass is most preferred. When the content of the water reducing agent is within the above range, good fluidity is likely to be obtained when mortar is formed, and strength development is likely to be improved during curing.

The grout mortar composition of this embodiment may contain a set retarder. Examples of setting retarders include organic acids such as citric acid, gluconic acid, malic acid, and tartaric acid, or salts thereof; 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 powder or liquid (for example, in the form of an aqueous solution, emulsion, or suspension). The setting retarders may be used singly 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, more preferably 0.2 parts by mass with respect to 100 parts by mass of the binder. ~0.4 parts by weight is most preferred. When the content of the setting retarder is within the above range, it is easier to ensure the pot life, and the initial strength development is less likely to deteriorate.

Various admixtures (materials) may be added to the grout mortar composition of the present embodiment as long as the effects of the present invention are not impaired. Examples of admixtures (materials) include expansion agents, foaming agents, waterproof agents, rust inhibitors, shrinkage reducing agents, water retention agents, pigments, water repellent agents, anti-efflorescence agents, and fibers.

The grout mortar composition of the present embodiment can be prepared by mixing the above components with a kneading device that is commonly used, and the device is not particularly limited. Examples of kneading tools include hand mixers, tilting mixers, bread mixers, twin-screw mixers, and the like.

[Grout mortar]
The grout mortar composition of the present embodiment can be prepared as grout mortar by mixing with water, and the content of water may be appropriately adjusted depending on the application. The content of water is preferably 22 to 40 parts by mass, more preferably 23 to 37 parts by mass, and most preferably 25 to 34 parts by mass with respect to 100 parts by mass of the binder. When the water content is within the above range, it becomes easier to ensure fluidity when formed into a mortar, further suppress drying shrinkage during curing, and further improve strength development.

The grout mortar of this embodiment conforms to JIS R 5201:2015 "Physical test method for cement" 12. According to the flow test, the flow value (0 stroke) measured at 20° C. is preferably 150 to 220 mm, more preferably 155 to 210 mm, and most preferably 160 to 200 mm. When the grout mortar has a flow value (0 stroke) within the above range, the mortar is easy to prepare, and sag is less likely to occur even on an inclination or the like.

The grout mortar of the present embodiment can be prepared by mixing the components described above with a commonly used kneading device, and the device is not particularly limited. Examples of kneading tools include hand mixers, tilting mixers, bread mixers, and twin shaft mixers.

The grout mortar composition and grout mortar of the present embodiment are excellent in rapid hardening property and strength development property while securing 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 the convenience of the drawings, the dimensional ratios in the drawings do not necessarily match 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 the concrete floor slab 1 from the concrete floor slab 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 concrete floor slabs and concrete floor slabs partially repaired with polymer cement or the like.

The grout mortar layer 2 is obtained by curing the grout mortar of the present embodiment described above. The thickness of the grout mortar layer 2 is preferably 5 to 50 mm, more preferably 10 to 40 mm, more preferably 12 to 30 mm, from the viewpoint of excellent cost and sufficient repair/reinforcing effect. Most preferably there is.

The waterproof layer 3 is made by curing a thermosetting resin. Since the waterproof layer 3 is formed on the grout mortar layer 2 in the concrete structure 10 , it is possible to further prevent water from entering the concrete floor slab 1 . Examples of thermosetting resins include epoxy resins, urethane resins, unsaturated polyester resins, and the like. The thermosetting resin is preferably an epoxy resin or a urethane resin from the viewpoint of being more excellent in waterproofness. The thickness of the waterproof layer is not particularly limited as long as it is a thickness that 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, as long as they are commonly used. From the viewpoint of further protecting the floor slab layer 1, the thickness of the surface layer 4 is preferably 50 to 100 mm, more preferably 60 to 80 mm.

In the concrete structure 10 of the present embodiment, the concrete floor slab 1, the grout mortar layer 2, the waterproof layer 3, and the surface layer 4 are laminated in this order from the concrete floor 1 side, and other layers are excluded. not something to do. For example, the concrete structure 10 may further include a second waterproof layer made 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 casting the above-described grout mortar on a concrete floor slab 1 to form a grout mortar layer 2, and a step of applying a thermosetting resin on the grout mortar layer 2. It comprises a step of applying and curing to form a waterproof layer 3 made of a hardened 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 described below.

In the step of forming the grout mortar layer 2 on the concrete floor slab 1, from the viewpoint of further improving the adhesiveness between the concrete floor slab 1 and the grout mortar layer 2, the surface of the concrete floor slab 1 is subjected to a water jet, Polishing such as shot blasting or manual chipping is preferred.

In the step of forming the waterproof layer 3 on the grout mortar layer 2, the thermosetting resin may be applied on the grout mortar layer 2 before the grout mortar setting time, and the thermosetting resin may be applied on the grout mortar layer 2 after the grout mortar setting time. may be coated with a thermosetting resin. From the viewpoint of further suppressing cracking of the grout mortar that constitutes the grout mortar layer 2 during hardening and further improving waterproofness, it is preferable to apply the thermosetting resin before the completion time of the grout mortar. As used herein, the term "finishing time" refers to that measured according to "JIS A 1147:2007 Concrete setting time test method". The amount of thermosetting resin to be applied is preferably 250 to 750 g/m ² , more preferably 350 to 650 g/m ² , from the viewpoint that it can be applied in just the right amount per 1 m ² and is more effective. Preferably, 400-600 g/m ² is most preferred.

A thermosetting resin composition obtained by adding known additives such as a curing agent, a curing accelerator, and a solvent to the above-described 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 placing concrete on the waterproof layer 3 according to a known method.

In the concrete structure of the present embodiment, the concrete floor slab is repaired or reinforced with the hardened grout mortar described above, and the hardened grout mortar is waterproofed with a waterproof layer, so the durability is extremely high. is.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these. In addition, No. The grout mortar compositions of 3, 5 and 6 are reference examples.

Materials used in 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: anhydrous gypsum (abbreviation CS)
Peroxide substance: Sodium percarbonate Alkali metal carbonate: Lithium carbonate Setting retardant: Citric acid Water reducing agent: Polycarboxylic acid-based high-performance water-reducing agent Anti-foaming agent: Polyether-based anti-foaming 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)

[Mixing design of grout mortar composition]
The amounts of various materials shown in Table 1 are used, and 0.1 parts by mass of sodium percarbonate, 0.2 parts by mass of lithium carbonate, The mixture was designed to contain 0.3 parts by mass of the acid and 0.25 parts by mass of the water reducing agent.

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

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

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

Claims (10)

Containing a binder made of cement, calcium aluminates and gypsum, a fine aggregate, an antifoaming agent, and a thickening agent,
The cement is at least one selected from the group consisting of Portland cement, mixed cement, filler cement and environmentally friendly cement,
The mass ratio of the cement is 60 to 95% by mass with respect to the total mass of the binder,
The total content of the antifoaming agent and the thickening agent is 0.03 to 0.4 parts by mass with respect to 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 1.6 to 9,
A grout mortar composition for floor slab repair or floor slab reinforcement, wherein the content of the fine aggregate is 30 to 140 parts by mass with respect to 100 parts by mass of the binder. The grout mortar composition according to claim 1, wherein the antifoaming agent is a polyether antifoaming agent. 3. A grout mortar composition according to claim 1 or 2, wherein the thickener is a cellulosic thickener. A grout mortar composition according to any one of claims 1 to 3, further comprising an alkali metal carbonate. A grout mortar composition according to any one of claims 1 to 4, further comprising a peroxide substance. comprising the grout mortar composition according to any one of claims 1 to 5 and water,
Grout mortar, wherein the water content is 22 to 40 parts by mass with respect to 100 parts by mass of the binder. JIS R 5201:2015 "Physical test methods for cement"12. The grout mortar according to claim 6, which has a flow value (0 stroke) of 150 to 220 mm measured in a 20°C environment according to a flow test. On the concrete floor slab, from the concrete floor slab side, a grout mortar layer made of the hardened grout mortar according to claim 6 or 7 , a waterproof layer made of a hardened thermosetting resin, and asphalt or concrete A concrete structure in which the surface layers are laminated in this order. The concrete structure according to claim 8, wherein said thermosetting resin is epoxy resin or urethane resin. A step of placing the grout mortar according to claim 6 or 7 on a concrete floor slab to form a grout mortar layer;
a step of applying and curing a thermosetting resin on the grout mortar layer before the grout mortar finishes to form a waterproof layer composed of a cured body of the thermosetting resin;
and forming a surface layer made of asphalt or concrete on the waterproof layer.

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