JP2017101406A - Sound-insulating wall and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound-insulating wall that has high strength, offers a fine structure of a cured body, has a thin wall, and achieves reductions in weight and construction cost.SOLUTION: A sound-insulating wall comprises a cured body of a cement composition containing (A) cement, (B) silica fume, (C) inorganic powder, aggregate A with a maximum particle diameter of 1.2 mm or less, high-performance water-reducing agent, antifoaming agent, and water, with following properties and content percentages of (A) cement: 55-65 vol.%, (B) silica fume of with a BET specific surface of 15-25 m/g: 5-25 vol.%, (C) inorganic powder with a 50% volume cumulative particle diameter of 0.8-5 μm: 15-35 vol.% (where, the total content percentage of cement, silica fume, and inorganic powdery percentage content is 100 vol.%).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sound insulation wall excellent in sound insulation and durability and a method for producing the same.

The sound insulation wall is required to have a function of effectively blocking noise generated on railways and highways. And as the material of the sound insulation wall, hard synthetic resin, iron plate, reinforced concrete, fiber reinforced concrete and the like are known. Since the concrete sound insulation wall is superior in sound insulation, strength, durability, workability, and the like as compared with hard synthetic resin and iron plate, the sound insulation wall can be constructed by concrete alone. However, since a concrete sound insulation wall that satisfies the above-mentioned performance is thick and heavy, a material that can easily transport and install the concrete sound insulation wall is required. Therefore, in Patent Document 1, cement, pozzolanic fine powder having an average particle diameter of 1.0 μm or less, fine aggregate having a maximum particle diameter of 2 mm or less, metal fiber or organic fiber, quartz powder having an average particle diameter of 3 to 20 μm, average A cured product (cement composition) of a composition containing fibrous particles or flaky particles having a particle size of 1 mm or less, a water reducing agent, and water has been proposed as a sound insulating wall.
The hardened body is superior in durability because it has high strength and the structure of the hardened body is dense compared with conventional sound insulation walls made of ordinary concrete, but if these characteristics can be improved, the durability will be further improved. In addition, the thickness of the sound insulation wall can be further reduced, and the weight can be reduced and the construction cost of the sound insulation wall can be reduced.

JP 2007-270540 A

  Accordingly, an object of the present invention is to provide a sound insulation wall and the like that have high strength and a hardened structure that is dense and excellent in sound insulation, that the sound insulation wall is thin and lightweight, and that the construction cost of the sound insulation wall can be reduced.

As a result of intensive studies to solve the above problems, the present inventor has found that cement, silica fume having a BET specific surface area of 15 to 25 m ² / g, inorganic powder having a 50% volume cumulative particle size of 0.8 to 5 μm, and the largest particles Cement, silica fume, and inorganic powder in aggregate 100% by volume of aggregate A having a diameter of 1.2 mm or less, high-performance water reducing agent, antifoaming agent, and water, and a total content of cement, silica fume, and inorganic powder It was found that a sound insulating wall made of a cured body of a cement composition having a content of each in a specific range can achieve the object, and the present invention was completed.

That is, the present invention provides the following [1] to [8].
[1] (A) cement, (B) silica fume, and (C) inorganic powder, aggregate A having a maximum particle size of 1.2 mm or less, high-performance water reducing agent, antifoaming agent having the following characteristics and content: And a sound insulation wall comprising a hardened body of a cement composition containing water.
(A) Cement: 55-65% by volume
(B) Silica fume having a BET specific surface area of 15 to 25 m ² / g: 5 to 25% by volume
(C) Inorganic powder having a 50% volume cumulative particle size of 0.8 to 5 μm: 15 to 35% by volume
(However, the total content of cement, silica fume, and inorganic powder is 100% by volume.)
[2] The cement has a particle size obtained by polishing at least one selected from medium heat Portland cement and low heat Portland cement, and shaping the angular surface portion of the cement particles into a rounded shape. A cement polishing product comprising coarse particles of 20 μm or more and fine particles having a particle size of less than 20 μm generated by the polishing treatment,
The sound insulation wall according to [1], wherein the cement polished product has a 50% volume cumulative particle size of 10 to 18 μm and a Blaine specific surface area of 2100 to 2900 cm ² / g.
[3] The sound insulating wall according to [1] or [2], further including 3% by volume or less of one or more selected from metal fibers, organic fibers, and carbon fibers.
[4] The sound insulating wall according to any one of [1] to [3], which is made of a cementitious hardened body having a compressive strength of 330 N / mm ² or more.
[5] The sound insulating wall according to any one of [1] to [3], further including an aggregate B having a maximum particle size of more than 1.2 mm and not more than 13 mm.
[6] The sound insulating wall according to [5], which is made of a cementitious hardened body having a compressive strength of 300 N / mm ² or more.

[7] A method for producing the sound insulation wall according to any one of [1] to [6], wherein the cement composition is kneaded and then placed in a mold to form an uncured molding. A molding process to obtain a body;
After the uncured molded body is sealed or air-cured at 10 to 40 ° C. for 24 hours or more, it is demolded from the mold to obtain a cured body,
About the said hardening body, the heat curing process which performs any one or both of the steam curing or warm water curing of 70 degreeC or more and less than 100 degreeC for 6 hours or more, and the autoclave curing for 1 hour or more at 100-200 degreeC is obtained. When,
A method for producing a sound insulation wall, comprising: heating the cured body after heat curing at 150 to 200 ° C. for 24 hours or more (excluding heating by autoclave curing) to obtain the sound insulation wall.
[8] The method for producing a sound insulation wall according to [7], further including a water absorption step for allowing the cured body to absorb water between the room temperature curing step and the heat curing step.
The sound insulation wall of the present invention includes a sound insulation wall block.

The sound insulation wall of the present invention has a high compressive strength (for example, 300 N / mm ² or more) and a dense hardened body structure. Therefore, the sound insulation wall is excellent in sound insulation, the sound insulation wall is thin and lightweight, and the construction cost of the sound insulation wall can be reduced. Excellent durability such as wear resistance, dimensional stability, water barrier, salt barrier, and freeze / thaw resistance.

It is a front view of an example of the block for sound insulation walls of the present invention. It is sectional drawing which shows the state which cut | disconnected the sound insulation wall block shown in FIG. 1 by the AA line | wire in FIG. It is a front view of an example of a high-speed airflow stirring device partially including a cross section cut in a direction perpendicular to the rotation axis of the rotor.

The sound insulation wall of the present invention is made of cement, silica fume having a BET specific surface area of 15 to 25 m ² / g (hereinafter sometimes abbreviated as “silica fume”), inorganic powder having a 50% volume cumulative particle size of 0.8 to 5 μm ( Hereinafter, it may be abbreviated as “inorganic powder”), aggregate A having a maximum particle size of 1.2 mm or less (hereinafter, abbreviated as “aggregate A”), high-performance water reducing agent, antifoaming agent. In addition, the total content of cement, silica fume, and inorganic powder is 100% by volume, and the cement contains 55-65% by volume, silica fume 5-25% by volume, and inorganic powder 15-35% by volume. It consists of a hardened body of a cement composition.
Hereinafter, the cement composition used in the present invention will be described in detail.

The type of cement is not particularly limited, and is selected from, for example, various Portland cements such as ordinary Portland cement, early-strength Portland cement, super early-strength Portland cement, moderately hot Portland cement, sulfate-resistant Portland cement, and low heat Portland cement. More than species can be used.
Among these, from the viewpoint of improving the fluidity of the cement composition, it is preferably at least one selected from medium heat Portland cement and low heat Portland cement.

Further, from the viewpoint of improving the fluidity of the cement composition and increasing the compressive strength of the cementitious hardened body, the cement is preferably polished at least one selected from moderately hot Portland cement and low heat Portland cement. A cement containing a coarse particle having a particle size of 20 μm or more formed by processing and shaping an angular surface portion of the cement particle into a rounded shape, and a fine particle having a particle size of less than 20 μm generated by the polishing treatment A cement-polished product having a 50% volume cumulative particle size of 10 to 18 μm and a brain specific surface area of 2100 to 2900 cm ² / g is used.

The upper limit of the particle size of the coarse particles is not particularly limited, and is usually 200 μm in consideration of the general particle size of the cement to be polished. From the viewpoint of increasing the compressive strength of the cementitious hardened body, preferably 100 μm. It is.
The lower limit of the particle size of the fine particles is not particularly limited, and is preferably 0.1 μm, more preferably 0.5 μm, from the viewpoint of improving the fluidity of the cement composition and improving workability when producing a sound insulation wall. It is.

50% volume cumulative particle size of the cement grinding process was preferably 10～18Myuemu, more preferably 12～16Myuemu, Blaine specific surface area is preferably 2100~2900cm ² / g, more preferably 2200~2700cm ² / g.
When the 50% volume cumulative particle size is 10 μm or more, the fluidity of the cement composition is improved. Further, when the 50% volume cumulative particle size is 18 μm or less, the compressive strength of the cementitious hardened body becomes higher.
Moreover, if the said brain specific surface area is 2100 cm < ² > / g or more, the compressive strength of a cementitious hardened body will become higher. When the brain specific surface area is 2900 cm ² / g or less, the fluidity of the cement composition is improved.

For the polishing treatment, a known polishing processing apparatus capable of polishing cement particles may be used. Examples of the polishing apparatus include a commercially available high-speed airflow agitator (for example, trade name “Hybritizer NHS-3” manufactured by Nara Machinery Co., Ltd.).
Hereinafter, the high-speed airflow stirring device will be described in detail with reference to FIG.
Cement, which is a raw material, is charged from the charging port 14 at the top of the high-speed airflow stirring device 10 with the on-off valve 18 open. After the introduction, the on-off valve 18 is closed.
The input cement enters the circulation circuit 13 through an opening provided in the middle of the circulation circuit 13, and then enters the collision chamber 17 that is a space for accommodating an object to be processed from the outlet 13 b of the circulation circuit 13. .
After the raw materials are charged, the rotor (rotary body) 11 disposed inside the stator 16 as a fixed body is rotated at a high speed, and a high-speed air current is generated by the rotor 11 and the blade 12 fixed to the rotor 11 to cause a collision. The cement in the chamber 17 is agitated. During agitation, cement particles enter the circulation circuit 13 from the inlet 13 a of the circulation circuit 13 provided in the collision chamber 17, and again from the outlet 13 b of the circulation circuit 13 provided in the central portion of the collision chamber 17. It is thrown into the collision chamber 17 and circulates.
In addition, the arrow shown with a dotted line in FIG. 1 shows the flow of particle | grains (a cement particle | grain and the coarse particle and fine particle which were produced | generated by grinding | polishing process).

  By stirring, the cement particles collide with the inner wall surface of the collision chamber 17, the rotor 11 and the blade 12, and the cement particles collide with each other. Coarse particles (particles having a particle size of 20 μm or more) and fine particles (particles having a particle size of less than 20 μm) that have changed to a rounded shape are generated.

The rotational speed of the rotor 11 is preferably 3000 to 4200 rpm, more preferably 3500 to 4000 rpm. When the rotational speed is 3000 rpm or more, the fluidity of the cement composition is improved. When the rotational speed exceeds 4200 rpm, the effect of improving the fluidity of the cement composition reaches its peak. Moreover, it is difficult for a rotational speed to exceed 4200 rpm on the performance of a high-speed airflow stirring apparatus.
The polishing time is preferably 10 to 60 minutes, more preferably 20 to 50 minutes, still more preferably 20 to 40 minutes, and particularly preferably 20 to 30 minutes. When the time is 10 minutes or more, the fluidity of the cement composition is improved. When the time exceeds 60 minutes, the effect of improving the fluidity of the cement composition reaches its peak.
The obtained cement-polished product (a mixture of coarse particles and fine particles) is discharged from the discharge port 15 by opening the discharge valve 19.

Silica fume has a BET specific surface area of 15 to 25 m ² / g, preferably 17 to 23 m ² / g, more preferably 18 to 22 m ² / g. When the specific surface area is less than 15 m ² / g, the compressive strength of the cementitious cured body is lowered. When this specific surface area exceeds 25 m < ² > / g, the fluidity | liquidity of a cement composition will fall.

Examples of inorganic powders having a 50% volume cumulative particle size of 0.8 to 5 μm include quartz powder (silica powder), volcanic ash, fly ash (classified or pulverized), slag powder, limestone powder, feldspar powder, mullite. 1 type or more chosen from a kind powder, an alumina powder, a silica sol, a carbide powder, and a nitride powder.
Among these, it is preferable to use quartz powder or fly ash from the viewpoint of improving the fluidity of the cement composition and increasing the compressive strength of the cementitious hardened body.
In the present specification, cement is not included in the inorganic powder having a 50% volume cumulative particle size of 0.8 to 5 μm.

The 50% volume cumulative particle size of the inorganic powder is 0.8 to 5 μm, preferably 1 to 4 μm, more preferably 1.1 to 3.5 μm, still more preferably 1.2 μm or more and less than 3 μm. When the particle size is less than 0.8 μm, the fluidity of the cement composition is lowered. When the particle size exceeds 5 μm, the compressive strength of the cementitious cured body is lowered.
The 50% volume cumulative particle size of the inorganic powder can be determined using a commercially available particle size distribution measuring device (for example, product name “Microtrac HRA Model 9320-X100” manufactured by Nikkiso Co., Ltd.).
Specifically, a cumulative particle size curve can be created using a particle size distribution measuring apparatus, and a 50% volume cumulative particle size can be determined from the cumulative particle size curve. At this time, 0.06 g of a sample is added to 20 cm ^{3 of} ethanol, which is a solvent for dispersing the sample, and an ultrasonic dispersion apparatus (for example, product name “US300” manufactured by Nippon Seiki Seisakusho Co., Ltd.) is used for 90 seconds. Measure with ultrasonic dispersion.

The maximum particle size of the inorganic powder is preferably 15 μm or less, more preferably 14 μm or less, and even more preferably 13 μm or less, from the viewpoint of further increasing the compressive strength of the cementitious cured body.
The 95% volume cumulative particle size of the inorganic powder is preferably 8 μm or less, more preferably 7 μm or less, and even more preferably 6 μm or less from the viewpoint of further increasing the compressive strength of the cementitious cured body.

The inorganic powder is preferably composed mainly of SiO ₂ (for example, quartz powder). SiO ₂ content of the inorganic powder is preferably 50 mass% or more, more preferably 60 mass% or more, if more preferably 70 mass% or more, the compressive strength of the cementitious cured body becomes higher.

In the cement composition, the total content of cement, silica fume, and inorganic powder is 100% by volume, and the cement content is 55 to 65% by volume, preferably 57 to 63% by volume. When the content is less than 55% by volume, the compressive strength of the cementitious cured body is lowered. When this content rate exceeds 65 volume%, the fluidity | liquidity of a cement composition will fall.
In the total content of 100% by volume of cement, silica fume, and inorganic powder, the content of silica fume is 5 to 25% by volume, preferably 7 to 23% by volume. When the content is less than 5% by volume, the compressive strength of the cementitious cured body is lowered. When this content rate exceeds 25 volume%, the fluidity | liquidity of a cement composition will fall.
In the total content of 100% by volume of cement, silica fume, and inorganic powder, the content of inorganic powder is 15 to 35% by volume, preferably 17 to 33% by volume. When the content is less than 15% by volume, the compressive strength of the cementitious cured body is lowered. When this ratio exceeds 35 volume%, the fluidity | liquidity of a cement composition will fall.

Aggregate A is river sand, land sand, sea sand, crushed sand, silica sand, artificial fine aggregate (for example, slag fine aggregate, fired fine aggregate obtained by firing fly ash, etc.), recycled fine aggregate, or These mixtures etc. are mentioned.
The maximum particle size of the aggregate A is preferably 1.2 mm or less, more preferably 1.1 mm or less, and further preferably 1.0 mm or less. When the maximum particle size is 1.2 mm or less, the compressive strength of the cementitious cured body is increased.
From the viewpoint of improving the fluidity of the cement composition and increasing the compressive strength of the cementitious hardened body, the particle size distribution of the aggregate A is 95% by mass or more in the aggregate content of the particle size of 0.6 mm or less, The content of the aggregate having a particle size of 0.3 mm or less is preferably 40 to 50% by mass, and the content of the aggregate having a particle size of 0.15 mm or less is preferably 6% by mass or less.
The content of aggregate A in the cement composition is preferably 20 to 40% by volume, more preferably 22 to 38% by volume, still more preferably 30 to 37% by volume, and particularly preferably 32 to 36% by volume. If this content rate is 20 volume% or more, the calorific value of a cement composition will become small, and the shrinkage amount of a cementitious hardened body will become small. If this ratio is 40 volume% or less, the compressive strength of a cementitious hardened body will become higher.

As the high-performance water reducing agent, a high-performance water reducing agent such as naphthalene sulfonic acid, melamine, or polycarboxylic acid can be used. Among these, from the viewpoint of improving the fluidity of the cement composition and increasing the compressive strength of the cementitious hardened body, a polycarboxylic acid-based high-performance water reducing agent is preferable.
The compounding amount of the high-performance water reducing agent is preferably 0.2 to 1.5 parts by mass in terms of solid content with respect to 100 parts by mass of the total amount of cement, silica fume, and inorganic powder, and more preferably 0.8. 4 to 1.2 parts by mass. When the amount is 0.2 parts by mass or more, the water reduction performance is improved and the fluidity of the cement composition is improved. When the amount is 1.5 parts by mass or less, the compressive strength of the cementitious cured body becomes higher.

  A commercial product can be used as the antifoaming agent. The blending amount of the antifoaming agent is preferably 0.001 to 0.1 parts by weight, more preferably 0.01 to 0.07 parts by weight with respect to 100 parts by weight of the total amount of cement, silica fume, and inorganic powder. More preferably, it is 0.01-0.05 mass part. When the amount is 0.001 part by mass or more, strength development of the cement composition is improved. When the amount exceeds 0.1 parts by mass, the effect of improving the strength development of the cement composition reaches its peak.

  The cement composition may contain one or more selected from metal fibers, organic fibers, and carbon fibers from the viewpoint of improving the bending strength, fracture energy, and the like of the cementitious hardened body. The content rate of the fiber in a cement composition becomes like this. Preferably it is 3 volume% or less, More preferably, it is 0.3-2.5 volume%, More preferably, it is 0.5-2.3 volume%. When the proportion is 3% by volume or less, the bending strength and fracture energy of the cementitious hardened body are improved without lowering the fluidity and workability of the cement composition.

Examples of metal fibers include steel fibers, stainless fibers, and amorphous fibers. Among these, steel fibers are excellent in strength, and are preferable from the viewpoints of cost and availability.
The dimension of the metal fiber is 0.01 to 1.0 mm in diameter and 2 to 30 mm in length from the viewpoint of preventing material separation of the metal fiber in the cement composition and improving the bending strength of the cementitious hardened body. The diameter is preferably 0.05 to 0.5 mm, and the length is more preferably 5 to 25 mm. Further, the aspect ratio (fiber length / fiber diameter) of the metal fiber is preferably 20 to 200, more preferably 40 to 150.
Furthermore, the shape of the metal fiber is preferably a shape that imparts some physical adhesion (for example, a spiral shape or a waveform) rather than a straight shape. In the case of a spiral shape or the like, the metal fiber and the matrix secure the stress while being pulled out, so that the bending strength of the cementitious hardened body is improved.

The organic fiber is not particularly limited as long as it can withstand the heating in the method for producing a sound insulating wall of the present invention described later, and examples thereof include aramid fiber, polyparaphenylenebenzobisoxazole fiber, polyethylene fiber, polyaryt fiber, and polypropylene fiber.
Examples of the carbon fiber include PAN-based carbon fiber and pitch-based carbon fiber.
The dimensions of the organic fiber and the carbon fiber are 0.005 to 1.0 mm in diameter and 2 in length from the viewpoint of preventing material separation of these fibers in the cement composition and improving the fracture energy of the cementitious hardened body. It is preferably ˜30 mm, more preferably 0.01 to 0.5 mm in diameter and 5 to 25 mm in length. Moreover, the aspect ratio (fiber length / fiber diameter) of the organic fiber and the carbon fiber is preferably 20 to 200, more preferably 30 to 150.

  Tap water can be used as water. The amount of water is preferably 10 to 20 parts by mass, more preferably 11 to 18 parts by mass, and further preferably 14 to 16 parts by mass with respect to 100 parts by mass of the total amount of cement, silica fume, and inorganic powder. . When the amount is 10 parts by mass or more, the fluidity of the cement composition is improved. When the amount is 20 parts by mass or less, the compressive strength of the cementitious cured body becomes higher.

The flow value before hardening of the mortar composed of the cement composition (not including the aggregate B described later) is 15 times in the method described in “JIS R 5201 (physical test method for cement) 11. Flow test”. The value measured without performing the falling motion (hereinafter, also referred to as “zero stroke flow value”) is preferably 200 mm or more, more preferably 210 mm or more, and even more preferably 220 mm or more.
When the flow value is 200 mm or more, workability when manufacturing the sound insulation wall is improved.
The compressive strength of the (containing no aggregate B to be described later) mortar consisting of cement composition cementitious cured product obtained by curing is preferably 330N / mm ² or more, more preferably 350 N / mm ² or more , more preferably 370N / mm ² or more, and particularly preferably 400 N / mm ² or more.

The cement composition used in the present invention can include aggregate B having a maximum particle size of more than 1.2 mm and 13 mm or less.
Aggregate B is river sand, mountain sand, land sand, sea sand, crushed sand, quartz sand, artificial fine aggregate (for example, slag fine aggregate, calcined fine aggregate obtained by firing fly ash, etc.), regenerated fine bone Wood, river gravel, mountain gravel, land gravel, crushed stone, artificial coarse aggregate (for example, slag coarse aggregate, calcined coarse aggregate obtained by firing fly ash, etc.), recycled coarse aggregate, or a mixture thereof Can be mentioned.
The maximum particle size of the aggregate B is preferably 13 mm or less, more preferably 12 mm or less, still more preferably 11 mm or less, and particularly preferably 10 mm or less. When the maximum particle size is 13 mm or less, the strength development of the cement composition is improved, and for example, a compressive strength of 300 N / mm ² or more can be developed.
Further, the maximum particle diameter of the aggregate B is a value exceeding 1.2 mm from the viewpoint of cost reduction and the like, preferably 3 mm or more, more preferably 5 mm or more, and further preferably 7 mm or more.
In this specification, the “maximum particle size” when the maximum particle size of the aggregate B is 5 mm or more is the nominal size of the smallest size sieve among the sieves through which 90% by mass or more of the entire aggregate B passes. Is the particle size of the aggregate B (generally known as the definition of the maximum particle size of the coarse aggregate).

The minimum particle size of the aggregate B is preferably a value exceeding the maximum particle size of the aggregate A, more preferably 2 mm or more, further preferably 3 mm or more, further preferably 4 mm or more, particularly preferably 5 mm or more (in this case) Corresponds to coarse aggregate).
In the present specification, the minimum particle size of the aggregate B is the aggregate B as a whole when accumulated from the smallest particle size of the aggregate B toward the largest particle size. The particle size of the aggregate B when it reaches 15% by mass.

In the present invention, the total content of aggregate A and aggregate B in the cement composition is preferably 25 to 40% by volume, more preferably 28 to 38% by volume, and even more preferably 30 to 36% by volume. . If this content rate is 25 volume% or more, the calorific value of a cement composition will become small, and the shrinkage amount of a cementitious hardened body will also become small. If this content rate is 40 volume% or less, the strength development property of a cement composition will improve.
The content of aggregate B with respect to the total content of 100% by volume of aggregate A and aggregate B is preferably 40% by volume or less, more preferably 30% by volume or less, and even more preferably 25% by volume or less. If this content rate is 40 volume% or less, the strength expression (for example, compressive strength) of a cement composition will improve.
The compressive strength of a hardened cementitious material obtained by curing a cement composition (for example, concrete) containing aggregate B is preferably 300 N / mm ² or more, more preferably 320 N / mm ² or more, and even more preferably 340 N / mm. ² or more, particularly preferably 360 N / mm ² or more.

Hereinafter, the manufacturing method of the sound insulation wall which consists of cementitious hardened | cured material which the cement composition mentioned above hardened | cured is demonstrated in detail.
An example of a method for producing a sound insulation wall according to the present invention includes a molding step of placing a cement composition in a mold to obtain an uncured molded body, and an uncured molded body at 10 to 40 ° C. for 24 hours or more. After the sealing curing or in-air curing, demolding from the mold and obtaining a cured body, and for the cured body, steam curing or warm water curing at 70 ° C. or more and less than 100 ° C. for 6 hours or more; Perform one or both of autoclave curing at 200 ° C. for 1 hour or longer to obtain a cured body after heat curing, and heat the cured body after heat curing at 150 to 200 ° C. for 24 hours or longer ( However, it includes a high-temperature heating step of obtaining a sound insulation wall made of a hardened cementitious material.

[Molding process]
In this step, the cement composition is placed in a mold to obtain an uncured molded body.
The method of kneading the cement composition before placing is not particularly limited. Moreover, the apparatus used for kneading is not particularly limited, and a conventional mixer such as an omni mixer, a pan-type mixer, a biaxial kneading mixer, and a tilting mixer can be used. Further, the placing (molding) method is not particularly limited.
Further, the uncured molded body in this step may be composed of a cement composition in which bubbles in the cement composition are reduced or removed. By reducing or removing bubbles in the cement composition, the strength development of the cement composition is further improved.
The method for reducing or removing bubbles in the cement composition is as follows: (1) a method of kneading the cement composition under reduced pressure; (2) a pressure reduction before placing the cement composition after kneading into a mold. And (3) a method in which a cement composition is placed in a mold and then defoamed under reduced pressure.

[Normal temperature curing process]
In this step, the uncured molded body is formed at 10 to 40 ° C. (preferably 15 to 30 ° C.) for 24 hours or longer (preferably 24 to 96 hours, more preferably 24 to 72 hours, and further preferably 24 to 48 hours. ), Sealing, or curing in air, and then demolding from the mold to obtain a cured product.
If the curing temperature is 10 ° C. or higher, the curing time can be shortened. When the curing temperature is 40 ° C. or lower, the compressive strength of the cementitious cured body (sound insulation wall) can be further increased.
When the curing time is 24 hours or longer, defects such as chipping and cracking are less likely to occur during demolding.
In this step, it is preferable that the cured body is removed from the mold when the cured body exhibits a compressive strength of preferably ^{20 to} 100 N / mm ² , more preferably 30 to 80 N / mm ² . If the compressive strength is 20 N / mm ² or more, defects such as chipping and cracking are less likely to occur in the cured product during demolding. If the compressive strength is 100 N / mm ² or less, the cured product can absorb water with little effort in the water absorption step described later.

[Heat curing process]
In this step, the cured product obtained in the previous step is subjected to steam curing or hot water curing at 70 ° C. or more and less than 100 ° C. (preferably 75 to 95 ° C., more preferably 80 to 92 ° C.) for 6 hours or more, In this step, one or both of autoclave curing at 200 ° C. (preferably 160 to 190 ° C.) for 1 hour or longer is performed to obtain a cured product after heat curing.
In this step, when only steam curing or warm water curing is performed, the curing time is preferably 24 hours or more, more preferably 24 to 96 hours, and further preferably 36 to 72 hours. When performing only autoclave curing, the curing time is preferably 8 to 60 hours, more preferably 12 to 48 hours. When performing both steam curing or warm water curing and autoclave curing (for example, when performing autoclave curing after performing steam curing or warm water curing), the curing time in steam curing or warm water curing is preferably 6 to 72 hours. More preferably, it is 12 to 48 hours, and the curing time in the autoclave curing is preferably 1 to 24 hours, more preferably 4 to 18 hours.
In this step, if the curing temperature is within the above range, the curing time can be shortened, the compressive strength of the cementitious hardened body is improved, and if the curing time is within the above range, the cemented hardened body is compressed. Strength is improved.

[High temperature heating process]
In this step, the cured body after heat curing is heated at 150 to 200 ° C. (preferably 170 to 190 ° C.) for 24 hours or longer (preferably 24 to 72 hours, more preferably 36 to 48 hours), and heating (however, autoclave This is a process of obtaining a sound insulation wall made of a hardened cementitious material in which the cement composition is hardened.
The heating in this step is usually performed under a dry atmosphere (in other words, a state where water and water vapor are not artificially supplied).
If heating temperature is 150 degreeC or more, heating time can be shortened. If heating temperature is 200 degrees C or less, the compressive strength of a cementitious hardened body will improve more.
When the heating time is 24 hours or more, the compressive strength of the cementitious cured body is further improved.

[Water absorption process]
Between the normal temperature curing process and the heat curing process, a water absorption process for absorbing water in the cured body obtained in the normal temperature curing process may be included.
Examples of the method of causing the cured body to absorb water include a method of immersing the molded body in water. Further, in the method of immersing the molded body in water, from the viewpoint of increasing the amount of water absorption in a short time and increasing the compressive strength of the cementitious cured body, (1) immersing the molded body in water under reduced pressure. (2) A method in which the molded body is immersed in boiling water, and then the water temperature is lowered to 40 ° C. or less while the molded body is immersed. (3) The molded body is boiled. A method of removing the molded body from boiling water and then immersing the molded body in water of 40 ° C. or lower, and (4) the molded body in water under pressure. Or (5) a method of immersing the molded body in an aqueous solution in which a drug for improving water permeability into the molded body is dissolved.

Examples of the method of immersing the molded body in water under reduced pressure include a method using equipment such as a vacuum pump and a large-sized vacuum container.
Examples of the method of immersing the molded body in boiling water include a method using equipment such as a high-temperature and high-pressure vessel and a hot-hot water tank.
The time for immersing the cured body in water under reduced pressure or boiling water is preferably 3 minutes or more, more preferably 8 minutes or more, and even more preferably 20 minutes or more from the viewpoint of increasing the water absorption rate. is there. The upper limit of the time is preferably 60 minutes, more preferably 45 minutes, from the viewpoint of increasing the compressive strength of the cementitious cured body.

The water absorption rate in the water absorption process is determined when the cement composition does not contain coarse aggregate (the cement composition does not contain aggregate B, or the aggregate B in the cement composition is coarse aggregate (minimum particle size is 5 mm). In the case where the above does not apply), the ratio of water to 100% by volume of the cured body of φ50 × 100 mm is preferably 0.2% by volume or more, more preferably 0.3 to 2.0% by volume, and still more preferably 0.8. 35-1.7% by volume.
Further, when the cement composition contains coarse aggregate (when aggregate B in the cement composition corresponds to coarse aggregate), the ratio of water to 100 volume% of φ100 × 200 mm hardened body is preferably 0.00. It is 2 volume% or more, More preferably, it is 0.3-2.0 volume%, More preferably, it is 0.35-1.7 volume%. If these water absorption is 0.2 volume% or more, the compressive strength of a cementitious hardened body can be made higher.

Since the sound insulating wall of the present invention is made of a cementitious hardened body having a high compressive strength, cracks and the like are hardly generated, and the thickness of the sound insulating wall can be reduced. As a result, the sound insulating wall can be reduced in weight.
In addition, the sound insulation wall made of the hardened cementitious material is excellent in wear resistance. For example, the wear depth of the cementitious hardened body after 60 minutes measured according to “ASTM C779” is preferably 0.5 mm or less, more preferably 0.4 mm or less, and still more preferably 0.3 mm or less. It is.

Moreover, the sound insulation wall of the present invention is excellent in salt insulation (for example, chloride ions and sulfate ions do not easily penetrate into the sound insulation wall), water insulation and freeze-thaw resistance.
In addition, the sound insulation wall made of the hardened cementitious material is excellent in dimensional stability. For example, a 40 × 40 × 160 mm specimen measured according to “JIS A 1129-2: 2010 (Method for measuring changes in length of mortar and concrete—Part 2: Contact gauge method)” is stored for 6 months. The shrinkage strain of the hardened cementitious body after the treatment is preferably 10 × 10 ⁻⁶ or less, more preferably 8 × 10 ⁻⁶ or less, and further preferably 6 × 10 ⁻⁶ or less.
Furthermore, the sound insulation wall made of the cementitious hardened body has a large bending strength. For example, when the hardened cementitious body contains fibers, the hardened cementitious body measured in accordance with “Japan Society of Civil Engineers Standard JSCE-G 552-2010 (Bending strength and bending toughness test method of steel fiber reinforced concrete)”. the flexural strength is preferably 20 N / mm ² or more, more preferably 30 N / mm ² or more, more preferably 35N / mm ² or more.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.
[A. Examples 1 to 14 and Comparative Example 1]
[Materials used]
The materials used in Examples 1 to 14 and Comparative Example 1 are shown below.
(1) Cement: Low heat Portland cement (manufactured by Taiheiyo Cement)
(2) Silica fume A: BET specific surface area of 20 m ² / g
(3) Silica fume B: BET specific surface area of 17 m ² / g
(4) Inorganic powder A: silica powder, 50% volume cumulative particle size 2 μm, maximum particle size 12 μm, 95% volume cumulative particle size 5.8 μm
(5) Inorganic powder B: silica powder, 50% volume cumulative particle size 7 μm, maximum particle size 67 μm, 95% volume cumulative particle size 27 μm
(6) Aggregate A1 (fine aggregate): Silica sand (maximum particle size 1.0 mm, particle size of 0.6 mm or less: 98% by mass, particle size of 0.3 mm or less: 45% by mass, 0 .15 mm or less particle size: 3% by mass)
(7) Polycarboxylic acid-based high-performance water reducing agent: solid content 27.4% by mass, manufactured by Floric, trade name “Floric SF500U”
(8) Antifoaming agent: BASF Japan, trade name “Master Air 404”
(9) Water: Tap water (10) Metal fiber: Steel fiber (diameter: 0.2 mm, length: 15 mm)
(11) Aggregate B (coarse aggregate): hard sandstone crushed stone 1005 (particle size: 5-10 mm)

[Example 1]
The total content of cement, silica fume A and inorganic powder A was mixed so that the content of cement and the like would be the amount shown in Table 2. The obtained mixture and the aggregate A1 in which the content of the aggregate A1 in the cement composition was as shown in Table 2 were charged into an omnimixer and air-kneaded for 15 seconds.
Next, water, a polycarboxylic acid-based high-performance water reducing agent, and an antifoaming agent were charged into the omni mixer in the amounts shown in Table 2 and kneaded for 2 minutes.
After kneading, the kneaded material adhering to the side wall in the omni mixer was scraped off and further kneaded for 4 minutes. And the zero strike flow value of the cement composition after kneading was measured.

The obtained kneaded product was cast into a cylindrical mold having a diameter of 50 × 100 mm to obtain an uncured molded body. After the casting, the uncured molded body was sealed and cured at 20 ° C. for 48 hours, and then demolded to obtain a cured body. The compressive strength at the time of demolding was 50 N / mm ² .
This molded body was immersed in water in a reduced pressure desiccator for the time shown in Table 3 (shown as “under reduced pressure” in Table 3). The pressure reduction was performed using “Aspirator (AS-01)” manufactured by ASONE. The mass of the molded body before and after the immersion was measured, and the water absorption was calculated from the obtained measured value.
After the immersion, this molded body was subjected to steam curing at 90 ° C. for 48 hours, then cooled to 20 ° C., and then heated at 180 ° C. for 48 hours.
The compressive strength of the hardened cementitious body (molded body after heating) was measured according to “JIS A 1108 (Method for testing compressive strength of concrete)”.
In addition, a 30 × 30 × 6 cm specimen was manufactured in the same manner as the hardened cementitious body (molded body after heating), and the depth of grinding after 60 minutes was measured according to “ASTM C779”. did.
Table 3 shows each of the values of the zero strike flow value, the water absorption rate, the compressive strength, and the depth of wear. In addition, each value of the zero strike flow value in the below-mentioned Example and a comparative example, a water absorption rate, a compressive strength, and a grinding depth is also shown in Table 3.

[Example 2]
Cement composition and hardened cementitious body (molded body after heating) in the same manner as in Example 1 except that the blending amount of water per 100 parts by mass of the powder raw material was changed from 13 parts by mass to 15 parts by mass. Got.
In the same manner as in Example 1, the zero-flow value of the cement composition was measured. The compressive strength at the time of demolding was 45 N / mm ² .

[Example 3]
Instead of immersing the molded product after demolding in water in a reduced-pressure desiccator, the molded product was immersed in boiling water (boiling water) for the time shown in Table 3, and then the molded product was immersed in water. A cement composition and a hardened cementitious body (molded body after heating) were obtained in the same manner as in Example 1 except that the water temperature was 25 ° C.
In the same manner as in Example 1, the water absorption rate was calculated and the compressive strength of the cementitious hardened body was measured.
[Example 4]
Instead of immersing the molded article after demolding in water in a reduced-pressure desiccator, the cement composition and the cement composition and A hardened cementitious body (molded body after heating) was obtained.
In the same manner as in Example 1, the water absorption rate was calculated and the compressive strength of the cementitious hardened body was measured.

[Example 5]
Cement composition in the same manner as in Example 1, except that the content of silica fume A was changed from 10% by volume to 20% by volume and the content of the inorganic powder A was changed from 30% by volume to 20% by volume. And a hardened cementitious body (molded body after heating) was obtained.
In the same manner as in Example 1, the measurement of the zero-flow value was performed. The compressive strength at the time of demolding was 50 N / mm ² .

In addition, a 40 × 40 × 160 mm specimen was manufactured in the same manner as the hardened cementitious body, and “JIS A 1129-2: 2010 Mortar and Concrete Length Change Measuring Method—Part 2: Contact Gauge Method” The shrinkage strain when stored for 6 months was measured.
Moreover, the water permeability coefficient of the obtained cementitious hardened body was measured according to the water level permeability test method of “Geotechnical Society Standard JGS 0311-2009 (Soil permeability test method)”. As a result, water permeation was not observed and the water permeability coefficient was “0”.
Moreover, the obtained cementitious hardened body was immersed in artificial seawater for 6 months. Artificial seawater was prepared by dissolving the reagents shown in Table 1 in the amounts shown in Table 1 in distilled water.
After immersion, the concentration of chloride ions in the hardened cementitious material was measured using EPMA (manufactured by JEOL Ltd.), and the diffusion coefficient of chloride ions (shown as “diffusion coefficient” in Table 3) was calculated. did.
Furthermore, with respect to the obtained cementitious hardened body, the durability index (300 cycles) of “ASTM C666 75” using values measured in accordance with “JIS A 1148 (freezing and thawing test method of concrete)”. Was calculated. The durability index has a maximum value of 100, and the closer to the maximum value, the better the freeze-thaw resistance.
The above results are shown in Table 3. Table 3 also shows shrinkage strain, water permeability coefficient, diffusion coefficient, and durability index in Examples described later.

[Example 6]
Instead of immersing the molded product after demolding in water in a reduced-pressure desiccator, the cement composition and the cement composition were obtained in the same manner as in Example 5 except that immersion in boiling water was performed in the same manner as in Example 3. A hardened cementitious body (molded body after heating) was obtained.
In the same manner as in Example 1, the water absorption rate was calculated and the compressive strength of the cementitious hardened body was measured.

[Example 7]
Cement composition in the same manner as in Example 2, except that the content of silica fume A was changed from 10% by volume to 20% by volume and the content of inorganic powder A was changed from 30% by volume to 20% by volume. And a hardened cementitious body (molded body after heating) was obtained.
In the same manner as in Example 1, the measurement of the zero-flow value was performed. The compressive strength at the time of demolding was 45 N / mm ² .

[Example 8]
The cement composition was obtained in the same manner as in Example 7 except that the molded body after demolding was immersed in boiling water in the same manner as in Example 3 instead of being immersed in water in a reduced-pressure desiccator. And a hardened cementitious body (molded body after heating) was obtained.
In the same manner as in Example 1, the water absorption rate was calculated, and the compressive strength and ground depth of the hardened cementitious material were measured.
Further, in the same manner as in Example 5, measurement of shrinkage strain and water permeability coefficient, and calculation of chloride ion diffusion coefficient and durability index were performed.

[Example 9]
The total content of cement, silica fume A and inorganic powder A was mixed so that the content of cement and the like would be the amount shown in Table 2. The obtained mixture and the aggregate A1 in which the content of the aggregate A1 in the cement composition was as shown in Table 2 were charged into an omnimixer and air-kneaded for 15 seconds.
Next, water, a polycarboxylic acid-based high-performance water reducing agent, and an antifoaming agent are added to the omni mixer in the amounts shown in Table 2, and after kneading for 2 minutes, the kneaded material adhering to the side wall in the omni mixer is scraped. And kneading was continued for 4 minutes. Thereafter, the metal fibers having the metal fiber content in the cement composition shown in Table 2 were put into an omni mixer and kneaded for another 2 minutes.
About the obtained cement composition, it carried out similarly to Example 1, and measured the zero flow value.
Moreover, the cementitious hardening body (molded object) was obtained by the method similar to Example 1 using the obtained cement composition.
About the obtained cementitious hardened | cured material (molded object), it carried out similarly to Example 1, and measured the water absorption rate and the compressive strength.
Furthermore, the bending strength of the obtained cementitious hardened body was measured according to “Japan Society of Civil Engineers standard JSCE-G 552-2010 (bending strength and bending toughness test method of steel fiber reinforced concrete)”.

[Example 10]
Instead of immersing the molded body after demolding in water in a reduced-pressure desiccator, the cement composition and the cement composition were obtained in the same manner as in Example 9 except that immersion in boiling water was performed in the same manner as in Example 3. The cured product was obtained.
About a cement composition and its hardened | cured material, it carried out similarly to Example 9, and measured various physical properties.
Further, in the same manner as in Example 5, the water permeability coefficient was measured, the diffusion coefficient of chloride ions, and the durability index were calculated.

[Example 11]
The blending amount of water per 100 parts by mass of the powder raw material is changed from 13 parts by mass to 11 parts by mass, and the content ratio of the aggregate A1 is changed from 35.5% by volume to 30.0% by volume. The cement composition and the hardened cementitious body in the same manner as in Example 1 except that the blending amount of the agent was changed from 0.69 parts by mass to 0.76 parts by mass and the molded body was not immersed in water. Got.
In the same manner as in Example 1, the zero-flow value of the cement composition was measured. The compressive strength at the time of demolding was 54 N / mm ² .

[Example 12]
The molded body after demolding was immersed in boiling water (boiling water) for the time shown in Table 3, and then cooled until the water temperature reached 25 ° C. while the molded body was immersed in water. In the same manner as in Example 11, a cement composition and a hardened cementitious material were obtained.
In the same manner as in Example 1, the water absorption rate was calculated and the compressive strength of the cementitious cured body was measured.
Further, in the same manner as in Example 5, the water permeability coefficient was measured, the diffusion coefficient of chloride ions, and the durability index were calculated.

[Example 13]
The content rate of the aggregate A1 was changed from 30.0% by volume to 24.0% by volume, and the aggregate B was used in such an amount that the ratio of the aggregate B in the cement composition was 6.0% by volume. Prepared a cement composition having the same composition as the cement composition of Example 11.
The cement composition was manufactured in the same manner as in Example 1, after kneading each material (powder raw material, aggregate A1, water, polycarboxylic acid-based high-performance water reducing agent, and antifoaming agent), and further aggregate. B was put into an omnimixer and kneaded for 1 minute.
The obtained cement composition (kneaded material) was cast into a cylindrical mold of φ100 × 200 mm, and the cementitious hardening was performed in the same manner as in Example 1 except that the molded body was not immersed in water. Got the body.
The compressive strength of the cementitious cured body was measured in the same manner as in Example 1. The compressive strength at the time of demolding was 43 N / mm ² .

[Example 14]
The content ratio of the aggregate A1 was changed from 35.5 volume% to 28.5 volume%, and the aggregate B was used in such an amount that the content ratio of the aggregate B in the cement composition was 7.0 volume%. A cement composition was produced with the same formulation as that of Example 8 except for the above.
The cement composition was manufactured in the same manner as in Example 1, after kneading each material (powder raw material, aggregate A1, water, polycarboxylic acid-based high-performance water reducing agent, and antifoaming agent), The material B was put into an omni mixer and kneaded for 1 minute.
A hardened cementitious material was obtained in the same manner as in Example 8 except that the obtained cement composition (kneaded material) was cast into a cylindrical mold with a diameter of 100 mm x 200 mm.
In the same manner as in Example 1, the water absorption rate was calculated and the compressive strength of the cementitious hardened body was measured. The compressive strength at the time of demolding was 37 N / mm ² .
Further, in the same manner as in Example 5, the water permeability coefficient was measured, the diffusion coefficient of chloride ions, and the durability index were calculated.

[Comparative Example 1]
Cement, silica fume B, and inorganic powder B were mixed so that the content of cement and the like would be the amount shown in Table 2 in a total of 100% by volume of the content of powder raw materials (cement, silica fume, and inorganic powder). The obtained mixture and the amount of aggregate A1 in which the content of aggregate A1 in the cement composition was the amount shown in Table 2 were charged into an omnimixer and air-kneaded for 15 seconds.
Next, water, a polycarboxylic acid-based high-performance water reducing agent, and an antifoaming agent were charged into the omni mixer in the amounts shown in Table 2 and kneaded for 2 minutes.
After kneading, the kneaded material adhering to the side wall in the omni mixer was scraped off and further kneaded for 4 minutes.
Using the obtained kneaded material, a cementitious cured body was obtained in the same manner as in Example 1.
About the obtained kneaded material (cement composition) and its hardened | cured material, it carried out similarly to Example 1, and measured various physical properties.

[B. Examples 15 to 26, Comparative Examples 2 to 4]
[Materials used]
The materials used in Examples 15 to 26 and Comparative Examples 2 to 4 are shown below.
(1) Medium heat Portland cement: manufactured by Taiheiyo Cement (2) Low heat Portland cement: manufactured by Taiheiyo Cement (3) Silica fume C: BET specific surface area 14 m ² / g
(4) Silica fume D: BET specific surface area 20 m ² / g
(5) Inorganic powder: silica powder, 50% volume cumulative particle size 2 μm, maximum particle size 12 μm, 95% volume cumulative particle size 5.8 μm (same as inorganic powder A used in Examples 1-14)
(6) Aggregate A1 (fine aggregate): silica sand, maximum particle size 1.0 mm, particle size of 0.6 mm or less: 98% by mass, particle size of 0.3 mm or less: 45% by mass, 0 .Particle diameter of 15 mm or less: 3% by mass (the same as the aggregate A1 used in Examples 1 to 14)
(7) Aggregate A2 (fine aggregate): Kakegawa mountain sand, maximum particle size 5.0 mm
(8) Polycarboxylic acid-based high-performance water reducing agent: solid content 27.4% by mass; manufactured by Floric, trade name “Floric SF500U”
(9) Antifoaming agent: BASF Japan, trade name “Master Air 404”
(10) Water: tap water (11) Metal fiber: Steel fiber (diameter: 0.2 mm, length: 15 mm)
(12) Aggregate B (coarse aggregate): hard sandstone crushed stone 1005 (particle size: 5-10 mm)

[Manufacture of polished products of medium heat Portland cement and low heat Portland cement]
Medium-heated Portland cement or low-heat Portland cement was polished for 30 minutes under the condition of a rotational speed of 4000 rpm using a high-speed airflow stirrer (trade name “Hybritizer NHS-3” manufactured by Nara Machinery Co., Ltd.). In the polishing treatment, the amount of medium heat Portland cement or low heat Portland cement charged was 800 g per batch. The 50% volume cumulative particle size and Blaine specific surface area of the ground heat Portland cement or low heat Portland cement, and the intermediate heat Portland cement or low heat Portland cement polished product were measured. The results are shown in Table 4.
Further, when a secondary electron image of the polished material was observed using a scanning electron microscope, coarse particles (particles having a particle size of 20 μm or more) of the polished material were particles of medium heat Portland cement or low heat Portland cement ( Compared to those before the polishing treatment), there were few squared surface portions, and the surface portions were deformed into rounded shapes. Further, it was observed that fine particles (particles having a particle diameter of less than 20 μm) were present in the gaps between the coarse particles.

[Example 15]
The low heat Portland cement polished product, silica fume D, inorganic powder, and aggregate A1 are put into an omni mixer for 15 seconds so that the content of the low heat Portland cement polished product is the amount shown in Table 5. I went to the sky.
Next, water, a polycarboxylic acid-based high-performance water reducing agent, and an antifoaming agent were added to the omni mixer in the amounts shown in Table 5 and kneaded for 2 minutes. In addition, the compounding quantity of the antifoamer was 0.02 mass part with respect to 100 mass parts of powder raw materials.
After kneading, the kneaded material adhering to the side surface of the omni mixer was scraped off and kneaded for 4 minutes. The zero-flow value of the cement composition after kneading was measured.
Further, the cement composition after kneading was placed in a cylindrical mold having a diameter of 50 × 100 mm to obtain an uncured molded body. After casting, the uncured molded body was allowed to stand at 20 ° C. for 72 hours. Subsequently, it was demolded to obtain a cured body. The compression strength at the time of demolding of the molded product was 52 N / mm ² .
Further, the molded body was subjected to steam curing at 90 ° C. for 48 hours, and then cooled to 20 ° C., and further heated at 180 ° C. for 48 hours using a drying furnace.
The compressive strength of the hardened cementitious body (molded body after heating) was measured according to “JIS A 1108 (Method for testing compressive strength of concrete)”. The compressive strength was measured using a 100t universal testing machine (hydraulic) manufactured by Shimadzu Corporation.

[Example 16]
A cement composition and a hardened cementitious body (molded body after heating) were obtained in the same manner as in Example 15 except that a polished product of moderately hot portland cement was used instead of the polished product of low heat Portland cement. . The compression strength at the time of demolding of the molded product was 55 N / mm ² .
In the same manner as in Example 15, the zero-cast flow value and the like of the cement composition were measured.
[Example 17]
Except for changing the amount of water per 100 parts by mass of the powder raw material from 12 parts by mass to 15 parts by mass, in the same manner as in Example 16, the cement composition and the cementitious hardened body (molded body after heating) were obtained. Obtained. The compression strength at the time of demolding of the molded product was 50 N / mm ² .
In the same manner as in Example 15, the zero-cast flow value and the like of the cement composition were measured.

[Example 18]
The molded body after demolding was immersed in boiling water (boiling water) for 30 minutes, and then cooled until the water temperature reached 25 ° C. while the molded body was immersed in water (“Boiling water” in Table 6). In the same manner as in Example 15 except that steam curing was performed later, a cement composition and a cementitious hardened body (molded body after heating) were obtained.
In the same manner as in Example 15, the zero-cast flow value and the like of the cement composition were measured. In addition, the compressive strength of the cured body exceeded the measurement limit (511 N / mm ² ) of the measuring device.
Moreover, the mass of the molded object before and behind immersion was measured, and the water absorption was computed from the obtained measured value.
Further, in the same manner as in Example 5, the measurement of the depth of penetration and the water permeability coefficient, and the calculation of the diffusion coefficient and durability index of chloride ions were performed.

[Example 19]
The molded body after demolding was immersed in water for 30 minutes in a reduced-pressure desiccator (shown as “under reduced pressure” in Table 6), and then subjected to steam curing in the same manner as in Example 15, except that cement was used. A composition and a cementitious cured body (molded body after heating) were obtained.
In the same manner as in Example 15, the zero-cast flow value and the like of the cement composition were measured. In addition, the compressive strength of the cured body exceeded the measurement limit (511 N / mm ² ) of the measuring device.

[Example 20]
Except that the content of silica fume D was changed from 10% by volume to 20% by volume and the content of the inorganic powder was changed from 30% by volume to 20% by volume, a cement composition and A hardened cementitious body (molded body after heating) was obtained. The compression strength at the time of demolding of the molded product was 51 N / mm ² .
In the same manner as in Example 15, the zero-cast flow value and the like of the cement composition were measured.
[Example 21]
The cement composition and the hardened cementitious body (molded body after heating) were obtained in the same manner as in Example 20 except that the molded body after demolding was immersed in water for 30 minutes in a reduced-pressure desiccator and then subjected to steam curing. )
In the same manner as in Example 15, the zero-cast flow value and the like of the cement composition were measured. In addition, the compressive strength of the cured body exceeded the measurement limit (511 N / mm ² ) of the measuring device.
In addition, a 40 × 40 × 160 mm specimen was manufactured in the same manner as the cementitious hardened body, and “JIS A 1129-2: 2010 Mortar and concrete length change measuring method—Part 2: Contact gauge method” In conformity, the shrinkage strain was measured when stored for 6 months.

[Example 22]
The cement composition and the hardened cementitious body (molded body after heating) were obtained in the same manner as in Example 17 except that the molded body after demolding was immersed in water for 30 minutes in a reduced-pressure desiccator and then subjected to steam curing. )
In the same manner as in Example 15, the zero-cast flow value and the like of the cement composition were measured.

[Example 23]
The low heat Portland cement polished product, silica fume D, inorganic powder, and aggregate A1 are put into an omni mixer for 15 seconds so that the content of the low heat Portland cement polished product is the amount shown in Table 5. I went to the sky.
Next, water, a polycarboxylic acid-based high-performance water reducing agent, and an antifoaming agent were added to the omni mixer in the amounts shown in Table 5 and kneaded for 2 minutes. In addition, the compounding quantity of the antifoamer was 0.02 mass part with respect to 100 mass parts of powder raw materials.
After kneading, the kneaded material adhering to the side surface of the omni mixer was scraped off and kneaded for 4 minutes. Thereafter, the metal fibers having the metal fiber content in the cement composition shown in Table 5 were put into an omni mixer and kneaded for another 2 minutes.
About the obtained cement composition, it carried out similarly to Example 15, and measured the zero flow value.
Moreover, the cementitious hardening body (molded object) was obtained by the method similar to Example 18 using the obtained cement composition.
About the obtained cementitious hardened | cured material (molded object), it carried out similarly to Example 18, and measured the water absorption rate and the compressive strength. In addition, the compressive strength of the cured body exceeded the measurement limit (511 N / mm ² ) of the measuring device.
Moreover, the bending strength of the obtained cementitious hardened body was measured in accordance with “JSCE-G 552-2010 (Bending strength and bending toughness test method of steel fiber reinforced concrete)”.

[Example 24]
Instead of immersing the molded body after demolding in boiling water for 30 minutes, cement curing was carried out in the same manner as in Example 23 except that steam curing was performed after immersing in water in a decompressed desiccator for 30 minutes. A composition and a cementitious cured body (molded body after heating) were obtained.
Various physical properties of the cement composition and the hardened cementitious body (molded body after heating) were measured in the same manner as in Example 23. In addition, the compressive strength of the cured body exceeded the measurement limit (511 N / mm ² ) of the measuring device.

[Example 25]
The low heat Portland cement polished product, silica fume D, inorganic powder, and aggregate A1 are put into an omni mixer for 15 seconds so that the content of the low heat Portland cement polished product is the amount shown in Table 5. I went to the sky.
Next, water, a polycarboxylic acid-based high-performance water reducing agent, and an antifoaming agent were added to the omni mixer in the amounts shown in Table 5 and kneaded for 2 minutes. In addition, the compounding quantity of the antifoamer was 0.02 mass part with respect to 100 mass parts of powder raw materials.
After kneading, the kneaded material adhering to the side surface of the omni mixer was scraped off and kneaded for 4 minutes. Thereafter, the aggregate B was put into an omnimixer so that the ratio was the ratio shown in Table 5, and kneaded for another minute.
The cement composition after kneading was cast into a cylindrical mold with a diameter of 100 × 200 mm to obtain an uncured molded body. After casting, the uncured molded body was allowed to stand at 20 ° C. for 72 hours. Subsequently, the mold was removed to obtain a cured body. The compression strength at the time of demolding of the molded product was 41 N / mm ² .
Further, the molded body was subjected to steam curing at 90 ° C. for 48 hours, and then cooled to 20 ° C., and further heated at 180 ° C. for 48 hours using a drying furnace.
The compressive strength was measured in the same manner as in Example 15 for the obtained cementitious cured body (molded body after heating).

[Example 26]
Instead of using a low heat Portland cement polishing treatment, a medium heat hot Portland cement polishing treatment was used, and the molded product after demolding was immersed in water for 30 minutes in a reduced pressure desiccator and then subjected to steam curing. In the same manner as in Example 25, a hardened cementitious body (molded body after heating) was obtained.
About the cementitious hardened body, it carried out similarly to Example 18, and measured the water absorption rate and the compressive strength.

[Comparative Example 2]
Medium-heated Portland cement abrasives, silica fume C, aggregate A2, high-performance water reducing agent, and water are all added to the Hobart mixer in the amounts shown in Table 5, and then kneaded at low speed for 12 minutes. Then, a cured product of the cement composition was obtained in the same manner as in Example 15 except that the cement composition was prepared. In the same manner as in Example 15, the zero-cast flow value and the like of the cement composition were measured.
[Comparative Example 3]
Let's prepare a cement composition by pouring a medium-heated Portland cement abrasive, aggregate A2, high-performance water reducing agent, and water into the Hobart mixer all at once in the amounts shown in Table 5. However, it could not be kneaded.
[Comparative Example 4]
I tried to prepare a cement composition by putting the medium-heated Portland cement, silica fume C, aggregate A2, high-performance water reducing agent, and water into the Hobart mixer all at once with the formulation shown in Table 5. could not.
The results are shown in Table 6.

From Table 3 and Table 6, the compressive strength of the cementitious hardened bodies of Examples 1 to 12 and Examples 15 to 24 including aggregate A but not including aggregate B (coarse aggregate) is 350 N / mm ² or more. high. In particular, the compressive strength of the cementitious cured bodies of Examples 15 to 24 using cement that has been subjected to polishing treatment is as high as 420 N / mm ² or more. In Examples 9 to 10 and Examples 23 to 24 (where the cement composition includes metal fibers), the obtained hardened cementitious material has a compressive strength of 445 N / mm ² or more, and is extremely high. The bending strength is 40 N / mm ² or more.
Moreover, even if it contains aggregate B (Examples 13-14, Examples 25-26), the compressive strength of the cementitious cured body is as high as 333 N / mm ² or more.
Further, the depth of wear of the cementitious hardened bodies of Examples 1-2, 5, 8, 10, 12, 14, and 18 is as small as 0.37 mm or less.
Moreover, the shrinkage | contraction distortion of the cementitious hardened | cured material of Example 5, 8, 21 is as small as 5 * 10 < ^-6 > or less.
Furthermore, from the water permeability coefficient, the diffusion coefficient of chloride ions, and the durability index of the cementitious cured bodies of Examples 5, 8, 10, 12, 14, and 18, the obtained cementitious cured bodies were water-insulating and salt-insulating. , And excellent freeze-thaw resistance.
From these results, since the sound insulating wall of the present invention has a high strength and a dense hardened structure, the thickness of the sound insulating wall can be reduced, as well as salt insulation, wear resistance, dimensional stability, water insulation, and freeze-thaw. It turns out that it is excellent in durability, such as resistance.
On the other hand, the compressive strength of the cementitious cured bodies of Comparative Examples 1 and 2 is 290 N / mm ^2, which is lower than those of Examples 1 to 26. Further, the depth of wear of the cementitious cured body of Comparative Example 1 is 0.57 mm, which is larger than that of the example. Further, the cement compositions of Comparative Examples 3 to 4 could not be kneaded.

[Example 27]
The results of manufacturing a sound insulation wall and evaluating its sound insulation performance are described below. A sound insulation wall (block) having the shape shown in FIG. 1 was produced using the cement composition of Example 8 in the same manner as in Example 8. The outer dimensions of the obtained sound insulation wall were a width of 2000 mm, a height of 1500 mm, and a thickness of 15 mm. Next, with respect to the obtained sound insulation wall, sound transmission loss was measured at each frequency of 100 Hz, 200 Hz, 500 Hz, 1000 Hz, 2000 Hz, and 5000 Hz using an anechoic sound field device, and “measured value (dB) −standard value” was measured. (DB) "was calculated to evaluate the sound insulation performance. The results are shown in Table 7. The standard values in Table 7 are reference values for the sound insulation performance of railway elevateds. If the measured value exceeds the standard value, it can be said that the sound insulation performance is good. In Table 7, the case where the value of “measured value (dB) −standard value (dB)” was 8 or more was evaluated as “◎” (very good). As shown in Table 7, the sound insulation wall of the present invention has a very good sound insulation performance despite being as thin as 15 mm.

DESCRIPTION OF SYMBOLS 1 Sound insulation wall 2 Plate-shaped main body 2a Upper part 2b Lower part 3 Rib (both ends) 3a Upper part 3b Lower part 4 Rib (middle) 4a Upper part 4b Lower part 5 Bottom plate part 10 High-speed airflow stirring apparatus 11 Rotor 12 Blade 13 Circulation circuit 13a Circulation circuit inlet 13b Circulation circuit outlet 14 Input port 15 Discharge port 16 Stator 17 Collision chamber 18 On-off valve 19 Discharge valve

Claims (8)

(A) cement, (B) silica fume, and (C) inorganic powder, aggregate A having a maximum particle size of 1.2 mm or less, high-performance water reducing agent, antifoaming agent, and water having the following properties and content: A sound insulation wall comprising a cured product of a cement composition comprising:
(A) Cement: 55-65% by volume
(B) Silica fume having a BET specific surface area of 15 to 25 m ² / g: 5 to 25% by volume
(C) Inorganic powder having a 50% volume cumulative particle size of 0.8 to 5 μm: 15 to 35% by volume
(However, the total content of cement, silica fume, and inorganic powder is 100% by volume.) The cement has a particle size of 20 μm or more obtained by polishing one or more kinds selected from moderately hot Portland cement and low heat Portland cement, and shaping the angular surface portion of the cement particles into a rounded shape. A cement polishing product comprising coarse particles and fine particles having a particle size of less than 20 μm generated by the polishing treatment,
The sound insulating wall according to claim 1, wherein the cement polished product has a 50% volume cumulative particle size of 10 to 18 µm and a Blaine specific surface area of 2100 to 2900 cm ² / g.   Furthermore, the sound-insulating wall according to claim 1 or 2, comprising 3% by volume or less of at least one selected from metal fibers, organic fibers, and carbon fibers. The sound insulation wall according to any one of claims 1 to 3, wherein the sound insulation wall is made of a cementitious hardened body having a compressive strength of 330 N / mm ² or more.   Furthermore, the sound insulation wall of any one of Claims 1-3 containing the aggregate B whose maximum particle size exceeds 1.2 mm and is 13 mm or less. The sound insulation wall according to claim 5, comprising a cementitious hardened body having a compressive strength of 300 N / mm ² or more. A method for producing the sound insulation wall according to any one of claims 1 to 6, wherein the cement composition is kneaded and then placed in a mold to obtain an uncured molded body. Process,
After the uncured molded body is sealed or air-cured at 10 to 40 ° C. for 24 hours or more, it is demolded from the mold to obtain a cured body,
About the said hardening body, the heat curing process which performs any one or both of the steam curing or warm water curing of 70 degreeC or more and less than 100 degreeC for 6 hours or more, and the autoclave curing for 1 hour or more at 100-200 degreeC is obtained. When,
A method for producing a sound insulation wall, comprising: heating the cured body after heat curing at 150 to 200 ° C. for 24 hours or more (excluding heating by autoclave curing) to obtain the sound insulation wall.   The manufacturing method of the sound insulation wall of Claim 7 including the water absorption process which makes the said hardening body absorb water between the said normal temperature curing process and the said heating curing process.

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