Hydraulic composition

Abstract

To provide a hydraulic composition in which the integrated calorific value of hydration associated with the curing reaction during, for example, 20 hours from the preparation of the hydraulic composition is large even when fine aggregates having a high surface water ratio are used, a method for producing the same and a wet spraying method using the hydraulic composition.SOLUTION: There is provided a hydraulic composition which comprises (A) cement, (B) fine aggregates having a surface water ratio of 0.1% or more and 10% or less, (C) a polyalkylene oxide having a weight average molecular weight of 200000 or more and less than 1000000 and (D) water.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a hydraulic composition, a method for producing the same, and a wet spraying method using the hydraulic composition. [Background technology]

[0002] Concrete is an essential construction material for the development of mankind, and cement concrete in particular is produced by mixing cement, water, fine aggregate, and coarse aggregate, forming the mixture, and then hardening it. Examples of fine aggregates include natural aggregates such as river sand, land sand, mountain sand, sea sand, lime sand, and silica sand, which are defined by number 2311 in JIS A0203-2014, and artificial aggregates such as crushed sands of these, blast furnace slag fine aggregate, ferronickel slag fine aggregate, lightweight fine aggregate, and recycled fine aggregate. Most fine aggregates are inorganic materials composed primarily of silica, which are produced as a result of volcanic activity or industrial by-products. They are exposed to high temperatures during their production, making them porous due to the evaporation of hydration water, dehydration, and the burning of organic matter.

[0003] For this reason, in the concrete industry, fine aggregate is often used with air or water vapor inside it. However, if it is used while it still contains air inside, when water is added to make a slurry, water will be intermittently absorbed into the fine aggregate, reducing workability and causing cracks due to drying during the hardening process. Therefore, it is often used with water already absorbed inside the fine aggregate, in particular in a state where the inside of the fine aggregate is filled with water but the water has not bled to the surface, that is, in a dry surface-saturated state. At construction sites that are constantly affected by wind, rain, and dryness, it is difficult to prepare fine aggregate that is in a dry, water-saturated state on the surface. Also, since the amount of water in concrete has a significant effect on strength, one of the main properties required of concrete, dry or wet fine aggregate is used, and the moisture content is measured, and then the moisture content in fresh concrete is controlled to a constant level by adjusting the mix. The surface water content of fine aggregate is measured according to the method specified in JIS A 1111, and the concrete mix is ​​adjusted based on the calculated surface water ratio. However, at construction sites where the effects of wind, rain, and dryness are particularly severe, the surface water ratio fluctuates greatly, making mix adjustments complicated, and so attempts are being made to directly measure the water content of fresh concrete.

[0004] In addition, a spraying method using a hydraulic composition is used to prevent the collapse of exposed natural ground during tunnel construction, slope protection construction, etc. Among these methods, the wet spraying method is a method in which a hydraulic composition is prepared in a cement, aggregate, and water metering mix plant installed at an excavation work site, and then the hydraulic composition is transported to a transport / spraying machine by an agitator vehicle, and the hydraulic composition is sprayed from the spraying machine onto the natural ground surface until a specified thickness is achieved.

[0005] Patent Document 1 discloses a method for measuring the unit water content of fresh concrete, in which a transmitting antenna and a receiving antenna are arranged opposite each other with a sample in between, microwaves are radiated from the transmitting antenna, and the microwaves that pass through the sample are received by the receiving antenna and measured to calculate the amount of water contained in the sample based on the amount of microwave attenuation by the sample, in which the sample is fresh concrete, and the unit water content is calculated taking into account one or more of the amount of air in the fresh concrete, the water absorption rate and chloride concentration of the aggregate, and the temperature of the fresh concrete.

[0006] Patent Document 2 discloses a method for measuring the unit water content of fresh concrete or fresh mortar, which uses a moisture meter that transmits electromagnetic waves to fresh concrete or fresh mortar and receives electromagnetic waves reflected by moisture, and which is characterized by comprising an actual measurement step of installing the moisture meter in an open space at a work site through which fresh concrete or fresh mortar to be poured flows, and continuously measuring dynamic measurement values ​​of the fresh concrete or fresh mortar flowing and passing through the open space using the moisture meter.

[0007] Patent Document 3 discloses a quick-setting cement concrete with improved dust prevention effect, which uses cement, polyethylene oxide having a weight-average molecular weight of 1,000,000 to 500, inorganic fine powder consisting of talc and / or pyrophyllite, 50 to 80 volume % fine aggregate with a surface water content of 10 mass % or less, and coarse aggregate with a surface water content of 2 mass % or less. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2006-10369 A [Patent Document 2] JP 2015-21905 A [Patent Document 3] JP 2009-78934 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, unless special techniques such as those described in Patent Documents 1 and 2 are used, it is difficult to grasp the amount of water in fresh concrete, and there is a problem that fluctuations in the surface water ratio of fine aggregate cause variations in the strength of fresh concrete.

[0010] The present invention provides a hydraulic composition that increases the integrated heat of hydration associated with a hardening reaction, for example, over 20 hours from the preparation of the hydraulic composition, even when fine aggregate with a high surface water content is used, a method for producing the same, and a wet spraying method using the hydraulic composition. [Means for solving the problem]

[0011] The present invention relates to a hydraulic composition containing (A) cement (hereinafter referred to as component (A)), (B) fine aggregate having a surface water content of 0.1% or more and 10% or less (hereinafter referred to as component (B)), (C) a polyalkylene oxide having a weight average molecular weight of 200,000 or more and less than 1,000,000 (hereinafter referred to as component (C)), and (D) water (hereinafter referred to as component (D)).

[0012] The present invention also relates to a method for producing a hydraulic composition, which comprises mixing the (A) component, the (B) component, the (C) component, and the (D) component.

[0013] The present invention also relates to a wet spraying method comprising mixing the components (A), (B), (C) and (D) to produce a hydraulic composition, and spraying the hydraulic composition onto an object. Effect of the Invention

[0014] According to the present invention, there are provided a hydraulic composition which, even when fine aggregate with a high surface water content is used, exhibits a large integrated heat of hydration associated with a hardening reaction for, for example, 20 hours from the preparation of the hydraulic composition, a method for producing the same, and a wet spraying method using the hydraulic composition.

[0015] By increasing the integrated amount of heat generated by hydration accompanying the setting reaction for, for example, 20 hours from the preparation of the hydraulic composition, the setting strength of the hydraulic composition can be increased. In recent years, the SDGs have been proposed to realize a sustainable society. This invention contributes to improving the quality of hardened concrete, and is believed to be a technology that can contribute to SDGs No. 9, 11, and 12, for example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present inventors have found that even if fine aggregate with a high surface water ratio is used in the hydraulic composition, the integrated heat of hydration accompanying the hardening reaction for, for example, 20 hours from the preparation of the hydraulic composition becomes large. The reason why such an effect is manifested is not necessarily clear, but is presumed to be as follows. For example, as mentioned above, fresh concrete is prepared by mixing water, cement, fine aggregate, coarse aggregate, etc., but in order to improve uniform mixing, a process called "dry mixing" is used in which the cement, fine aggregate, and coarse aggregate are mixed in advance before adding water. In this case, if the surface water content of the fine aggregate is high, the cement is thought to form liquid bridges between the cement and fine aggregate and between the cement and cement through the water on the surface of the fine aggregate, and to adhere in the form of splices around the fine aggregate. Since the hydration reaction, which is the hardening reaction of cement, begins when the cement comes into contact with water, it is assumed that the hydration reaction will proceed to some extent even at the dry mixing stage, and the adhesion of the cement to the fine aggregate will become stronger. If water is added in this state and mixing begins, the cement, fine aggregate, and coarse aggregate will gradually turn into a slurry, but the cement lumps near the fine aggregate that have been solidified by liquid bridging forces will be difficult to remove and the amount of microscopic water relative to the cement will be insufficient, causing the cement hydration reaction to stagnate locally and decreasing the accumulated heat of hydration, which is directly linked to the strength of the hardened concrete. On the other hand, the polyalkylene oxide having a specific weight average molecular weight, which is component (C) of the present invention, has low adsorption to cement and does not inhibit the hydration reaction of cement, and by having a molecular weight above a certain level, it retains water on the surface of the fine aggregate by entanglement of its molecular chains and suppresses the formation of liquid bridges between the fine aggregate and cement, and by having a molecular weight below a certain level, it effectively retains water without being excessively hydrophobic molecularly, and is not accompanied by mixability or inactivation of the hydration reaction due to increased viscosity caused by significant entanglement of the molecular chains. Therefore, it is believed that even if a fine aggregate with a high surface water ratio is used, the accumulated heat of hydration associated with the hardening reaction of the cement becomes large.

[0017] [Hydraulic composition] <Component (A)> The hydraulic composition of the present invention contains cement as component (A). Examples of cement include ordinary Portland cement, belite cement, moderate heat cement, high-early strength cement, ultra-high-early strength cement, and sulfate-resistant cement, and may also include blast furnace slag cement, fly ash cement, and silica fume cement to which blast furnace slag, fly ash, silica fume, stone powder (calcium carbonate powder), etc. have been added. One or more of these may be used.

[0018] In the hydraulic composition of the present invention, the content of component (A) is, relative to 100 parts by mass of the hydraulic composition, preferably 10 parts by mass or more, more preferably 12 parts by mass or more, and even more preferably 14 parts by mass or more from the viewpoint of the strength of the hardened body, and is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less from the viewpoint of suppressing cracking of the hardened body.

[0019] <(B) component> The hydraulic composition of the present invention contains, as component (B), fine aggregate having a surface water content of 0.1% or more and 10% or less.

[0020] The surface water content of the fine aggregate, component (B), is 0.1% or more, preferably 0.5% or more, more preferably 1% or more, and 10% or less, preferably 5% or less, more preferably 3% or less, from the viewpoints of the strength of the hardened body and suppression of cracking in the hardened body. The surface water ratio of the fine aggregate of component (B) is measured by the method described in JIS A 1111. More precisely, it is measured at 20°C by the following procedure. 200 mL of tap water and 500.0 g of fine aggregate were placed in a 500 mL Chapman flask (KC-103, manufactured by Kansai Machinery Manufacturing Co., Ltd.), gently shaken, and left to stand for 30 minutes to degas and absorb water. The Chapman flask's scale (V) was recorded, and the surface water ratio was calculated as the average value of two tests based on the following formula. Surface water rate (%) ={(V-500.0)-(500.0 / surface dry density of each fine aggregate)} / {500.0-(V-500.0)}×100

[0021] Fine aggregate is defined as aggregate which passes entirely through a 10 mm sieve and at least 85% by weight through a 5 mm sieve. Examples of fine aggregates include those specified by number 2311 in JIS A0203-2014. Specific examples of fine aggregates include one or more types selected from river sand, land sand, mountain sand, sea sand, lime sand, silica sand and crushed sands thereof, blast furnace slag fine aggregate, ferronickel slag fine aggregate, lightweight fine aggregate (artificial and natural), and recycled fine aggregate.

[0022] In the hydraulic composition of the present invention, the content of the (B) component is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, even more preferably 60 parts by mass or more, and preferably 90 parts by mass or less, more preferably 85 parts by mass or less, even more preferably 80 parts by mass or less, based on 100 parts by mass of the hydraulic composition, from the viewpoint of the fluidity of the hydraulic composition.

[0023] In the hydraulic composition of the present invention, the mass ratio (B) / (A) of the content of the (A) component to the content of the (B) component is preferably 2 or more, more preferably 3 or more, and even more preferably 3.5 or more, from the viewpoint of the workability of the hydraulic composition, and is preferably 6 or less, more preferably 5.5 or less, even more preferably 5 or less, and even more preferably 4.5 or less, from the viewpoint of the fluidity of the hydraulic composition.

[0024] <(C) component> The hydraulic composition of the present invention contains, as component (C), a polyalkylene oxide having a weight average molecular weight of 200,000 or more and less than 1,000,000.

[0025] The weight average molecular weight of component (C) is, from the viewpoint of promoting the cement hydration reaction, 200,000 or more, preferably 250,000 or more, more preferably 300,000 or more, even more preferably 350,000 or more, and even more preferably 400,000 or more, and from the viewpoint of the workability of the hydraulic composition, less than 1,000,000, preferably 900,000 or less, more preferably 800,000 or less, even more preferably 700,000 or less, even more preferably 600,000 or less, and even more preferably 500,000 or less. In the case of commercially available products, the weight average molecular weight of the polyalkylene oxide may be a value based on the product information (catalog, etc.). The weight average molecular weight of the polyalkylene oxide can be determined by gel permeation chromatography (GPC) under the following measurement conditions. Measurement conditions: Equipment: Product name "LC-10AD" (manufactured by Shimadzu Corporation) Detector: Refractive index detector (RID) Column: Product name "SHODEX KF-804" (manufactured by Showa Denko K.K.) ·Measurement temperature: 30℃ ·Eluent:THF ·Flow rate: 1.0mL / min Sample concentration: 0.2% by mass (THF) Sample injection volume: 100μL Conversion standard: Polyethylene oxide

[0026] The component (C) preferably contains ethylene oxide and / or propylene oxide as polymerization units, and more preferably contains ethylene oxide. When component (C) contains ethylene oxide and propylene oxide as polymerization units, the ethylene oxide and propylene oxide may be either a random copolymer or a block copolymer. From the viewpoint of water solubility, the component (C) is preferably at least one selected from a copolymer of polyoxyethylene oxide and polypropylene oxide, and polyethylene oxide, and more preferably polyethylene oxide.

[0027] In the hydraulic composition of the present invention, the content of the (C) component is, relative to 100 parts by mass of the hydraulic composition, preferably 0.001 part by mass or more, more preferably 0.005 part by mass or more, and even more preferably 0.01 part by mass or more, from the viewpoint of promoting cement hydration reaction, and is preferably 1 part by mass or less, more preferably 0.5 part by mass or less, and even more preferably 0.1 part by mass or less, from the viewpoint of promoting cement hydration reaction and the workability of the hydraulic composition.

[0028] In the hydraulic composition of the present invention, the content of the (C) component, relative to 100 parts by mass of the (A) component, is 0.05 parts by mass or more, preferably 0.075 parts by mass or more, and more preferably 0.1 parts by mass or more, from the viewpoint of promoting cement hydration reaction, and is 2 parts by mass or less, preferably 1.75 parts by mass or less, more preferably 1.5 parts by mass or less, even more preferably 1 part by mass or less, and still more preferably 0.5 parts by mass or less, from the viewpoint of promoting cement hydration reaction and the workability of the hydraulic composition.

[0029] <(D) component> The hydraulic composition of the present invention contains water as the component (D). In the hydraulic composition of the present invention, the mass ratio (D) / (A) of the content of the (A) component to the content of the (D) component is 0.4 or more, preferably 0.45 or more, more preferably 0.5 or more, from the viewpoint of suppressing a decrease in the fluidity of the hydraulic composition, and is 0.8 or less, preferably 0.75 or less, more preferably 0.7 or less, from the viewpoint of the strength of the hardened body.

[0030] <Other ingredients, etc.> The hydraulic composition of the present invention may contain coarse aggregate as component (E) within the range not impairing the effects of the present invention. Coarse aggregate is aggregate that retains 85% or more by mass on a 5 mm mesh sieve. Examples of coarse aggregate include those specified by number 2312 in JIS A0203-2014. Examples of coarse aggregate include river gravel, land gravel, mountain gravel, sea gravel, limestone gravel, crushed stones of these, blast furnace slag coarse aggregate, ferro-nickel slag coarse aggregate, lightweight coarse aggregate (artificial and natural), and recycled coarse aggregate.

[0031] When the hydraulic composition of the present invention contains the component (E), the content of the component (E) is, from the viewpoint of the fluidity of the hydraulic composition, preferably 1 part by mass or more, more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, and preferably 50 parts by mass or less, more preferably 45 parts by mass or less, even more preferably 40 parts by mass or less, based on 100 parts by mass of the hydraulic composition.

[0032] The hydraulic composition of the present invention may contain a quick-setting admixture, but the content is limited from the viewpoint of suppressing cracking of the set body. The accelerator may be one or more selected from inorganic salt-based accelerators, cement mineral-based accelerators, and natural mineral-based accelerators. Examples of inorganic salt-based quick-setting agents include alkali metal aluminates, alkali metal carbonates, aluminum sulfate, gypsum dihydrate, gypsum hemihydrate, anhydrous gypsum, calcium chloride and silicates, calcium hydroxide, etc. Examples of cement mineral-based quick-setting agents include calcium aluminate and calcium sulfoaluminate, etc. Examples of natural mineral-based quick-setting agents include calcined alumite, etc.

[0033] In the hydraulic composition of the present invention, the content of the quick-setting admixture is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.1 parts by mass or less, per 100 parts by mass of component (A), from the viewpoint of suppressing cracking of the hardened body. The hydraulic composition of the present invention may not contain a quick-setting admixture.

[0034] The hydraulic composition of the present invention may contain, as necessary, one or more selected from dispersants, expansion agents, hardening accelerators, hardening retarders, polymers for cement, foaming agents, waterproofing agents, rust inhibitors, shrinkage reducing agents, pigments, fibers, water repellents, efflorescence inhibitors, etc. (excluding those corresponding to the above-mentioned components) within the scope not impairing the effects of the present invention.

[0035] The hydraulic composition of the present invention is most suitable for a wet spraying method in which even if fine aggregate with a high surface water content is used, the integrated heat of hydration accompanying the hardening reaction for, for example, 20 hours from the preparation of the hydraulic composition becomes large, and therefore the hydraulic composition must be prepared outdoors, and control of the surface water content of the fine aggregate is difficult. That is, the hydraulic composition of the present invention is suitable for wet spraying.

[0036] The present invention may be a hydraulic composition comprising the components (A), (B), (C), and (D). The components (A), (B), (C), and (D) are the same as those described in the hydraulic composition of the present invention. The other components other than the components (A) to (D) can be blended in the hydraulic composition in the same manner. The amounts and mass ratios of each component described in the hydraulic composition of the present invention can be applied to the hydraulic composition by replacing the contents with the amounts.

[0037] [Method for producing hydraulic composition] The present invention provides a method for producing a hydraulic composition, which comprises mixing the components (A), (B), (C) and (D). The components (A), (B), (C), and (D) are the same as those described in the hydraulic composition of the present invention. The other components other than the components (A) to (D) are also the same and can be mixed in the manufacturing method of the hydraulic composition of the present invention. The mixing amount and mass ratio of each component can be applied to the manufacturing method of the hydraulic composition of the present invention by replacing the content with the mixing amount with respect to the content and mass ratio of each component described in the hydraulic composition of the present invention. The method for producing the hydraulic composition of the present invention can be appropriately applied to the aspects described for the hydraulic composition of the present invention.

[0038] In the method for producing the hydraulic composition of the present invention, the mixing of the components (A), (B), (C), and (D) can be carried out by a known method. Specifically, the components (A), (B), (C), and (D) may be mixed simultaneously, but from the viewpoint of promoting the cement hydration reaction, it is preferable to add the component (C) to the component (B), add the component (A) and mix, and then add the component (D) to the mixture and further mix. A mixing mixer such as a pan-type forced mixer, a two-shaft forced mixer, or a tilting mixer can be used to mix these components.

[0039] [Wet spraying method] The present invention provides a wet spraying method comprising mixing components (A), (B), (C) and (D) to produce a hydraulic composition, and spraying the hydraulic composition onto an object.

[0040] The hydraulic composition in the wet spraying method of the present invention is the same as the hydraulic composition of the present invention, and the embodiments described in the hydraulic composition of the present invention and the manufacturing method thereof can be appropriately applied. The components (A), (B), (C), and (D) are the same as those described in the hydraulic composition of the present invention. The other components other than the components (A) to (D) are also the same and can be mixed in the method for producing the hydraulic composition. The mixing amount and mass ratio of each component can be applied to the manufacturing method of the hydraulic composition by replacing the content with the mixing amount with respect to the content and mass ratio of each component described in the hydraulic composition of the present invention.

[0041] In the spraying method of the present invention, the hydraulic composition thus prepared is sprayed onto an object, which corresponds to the so-called wet spraying method. The wet spraying method of the present invention can be carried out using conventional spraying equipment. The spraying equipment may be any equipment capable of performing wet spraying without any problems, and for example, the hydraulic composition may be pumped to a spraying machine using equipment such as "Ariva 280" manufactured by Arriva, and sprayed. EXAMPLES

[0042] The components in the table are as follows: <Component (A)> A-1: Ordinary Portland cement (manufactured by Taiheiyo Cement Corporation, specific gravity 3.16) <(B) component> B-1: Mountain sand (from Joyo City, Kyoto Prefecture, surface dry density 2.51)

[0043] <(C) component> C-1: Alcox R-1000 (manufactured by Meisei Chemical Industry Co., Ltd., polyethylene oxide, weight average molecular weight: 325,000) C-2: Alcox E-30 (manufactured by Meisei Chemical Industry Co., Ltd., polyethylene oxide, weight average molecular weight: 475,000) C-3: Alcox E-45 (manufactured by Meisei Chemical Industry Co., Ltd., polyethylene oxide, weight average molecular weight: 800,000) <Component (C') (comparison component of component (C))> C'-1: Alcox R-150 (manufactured by Meisei Chemical Industry Co., Ltd., polyethylene oxide, weight average molecular weight: 150,000) C'-2: Polyethylene oxide, molecular weight 1,000,000 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) <(D) component> D-1: Tap water (Wakayama City tap water, specific gravity 1.00)

[0044] (1) (B) Adjustment of the surface water content of the component The above (B) component was placed in a constant temperature air blower dryer DRM620DE (manufactured by Advantec Co., Ltd.) and dried at 105°C for 24 hours to obtain an absolute dry state. Next, after cooling to room temperature, it was spread out, and Wakayama City water was sprayed with a shoulder-mounted sprayer (manufactured by Kinboshi Co., Ltd.), while homogenizing with a shovel, and the surface water ratio measured by JIS A 1111 was adjusted to 0%, 1%, and 5%, respectively. The surface water ratios of the (B) components used are also shown in Table 1. Note that the one with a surface water ratio of 0% is the comparative component of the (B) component. In addition, in Reference Example 1, an attempt was made to adjust the surface water ratio to more than 10%, but this was not possible because the fine aggregate would not be able to retain water, and the following evaluation was not performed.

[0045] (2) Preparation of hydraulic composition Component (C) or (C') was added to component (B) so as to obtain the blending amount (parts by mass) shown in Table 1, and then component (A) was added, and the mixture was charged into a Hobart-type mixer described in JIS R 5201 and dry mixed at 62 rpm for 10 seconds. Next, component (D) was added so as to obtain the blending amount (parts by mass) shown in Table 1, and the mixture was kneaded at 62 rpm for 2 minutes to prepare a hydraulic composition.

[0046] (3) Measurement of the accumulated heat of hydration A 20.0 g sample of the hydraulic composition immediately after preparation, prepared by the method described in (2), was taken, and the integrated heat of hydration (kJ·h / g) from immediately after preparation until 20 hours later was measured using an isothermal calorimeter TAM Air (manufactured by TA Instruments), and used as an index of the strength of the hardened body. The results are shown in Table 1.

[0047] [Table 1]

[0048] In Table 1, the "amount (parts by mass) relative to (A)" of component (C) or (C') indicates the amount of component (C) or (C') relative to 100 parts by mass of component (A).

[0049] In Table 1, comparing the Examples and Comparative Examples with the same surface water ratio and blending amount of the (B) component (specifically, Examples 1 to 4 and Comparative Examples 1 to 3, and Example 5 and Comparative Example 4), the Examples of the present invention showed a large cumulative heat of hydration. This is considered to be because the polyalkylene oxide, which is the (C) component of the present invention, having a moderately large weight-average molecular weight, suppresses the formation of cement splices due to water derived from fine aggregate, and effectively promotes the hydration reaction of cement. As described above, even if fine aggregate with a high surface water ratio is used, the hydraulic composition of the present invention is most suitable for wet spraying construction methods in which the hydraulic composition must be prepared outdoors and the control of the surface water ratio of fine aggregate is difficult. Furthermore, in Example 4 and Comparative Example 1, the difference in the accumulated heat of hydration was 6 kJ h / g. However, considering that hydration, which is a chemical reaction, is visualized by thermal energy and the scale effect in actual concrete structures, this is by no means a small difference in the accumulated heat of hydration, and therefore can be said to be a significant difference.

Claims

1. A hydraulic composition containing (A) cement (hereinafter referred to as component (A)), (B) fine aggregate with a surface moisture content of 0.1% or more and 10% or less (hereinafter referred to as component (B)), (C) polyalkylene oxide with a weight-average molecular weight of 200,000 or more and less than 1,000,000 (hereinafter referred to as component (C)), and (D) water (hereinafter referred to as component (D)).

2. The hydraulic composition according to claim 1, wherein the mass ratio (B) / (A) of the content of component (A) to the content of component (B) is 2 or more and 6 or less.

3. The hydraulic composition according to claim 1 or 2, wherein the mass ratio (D) / (A) of the content of component (A) to the content of component (D) is 0.4 or more and 0.8 or less.

4. The hydraulic composition according to claim 1 or 2, wherein the content of component (C) is 0.05 parts by mass or more and 2 parts by mass or less per 100 parts by mass of component (A).

5. The hydraulic composition according to claim 1 or 2, wherein the content of the rapid setting agent is 1 part by mass or less per 100 parts by mass of component (A).

6. A hydraulic composition according to claim 1 or 2, for use in wet spraying.

7. A method for producing a hydraulic composition, comprising mixing (A) cement (hereinafter referred to as component (A)), (B) fine aggregate with a surface moisture content of 0.1% or more and 1% or less (hereinafter referred to as component (B)), (C) polyalkylene oxide with a weight-average molecular weight of 200,000 or more and less than 1,000,000 (hereinafter referred to as component (C)), and (D) water (hereinafter referred to as component (D)).

8. A method for producing a hydraulic composition according to claim 7, comprising adding component (C) to component (B), adding component (A) and mixing, and then adding component (D) to the mixture and mixing.

9. A wet spraying method comprising: (A) cement (hereinafter referred to as component (A)); (B) fine aggregate with a surface moisture content of 0.1% or more and 1% or less (hereinafter referred to as component (B)); (C) polyalkylene oxide with a weight-average molecular weight of 200,000 or more and less than 1,000,000 (hereinafter referred to as component (C)); and (D) water (hereinafter referred to as component (D)), to produce a hydraulic composition, and spraying the hydraulic composition onto an object.