TW201934518A - High strength grout composition and high strength grout mortar using same - Google Patents

Abstract

The invention is a high-strength grouting material composition, which contains cement with a particle content of 5 μm or less and 5 mass% or less and a median particle size of 15 μm or more, microporous ash, water-soluble calcium salt, water reducing agent, hair Foaming agent, antifoaming agent, and fine aggregate.

Description

High-strength grouting material composition and high-strength grouting mortar using the same

The invention relates to a high-strength grouting material composition mainly used in the field of civil engineering and construction, and a high-strength grouting mortar using the same.

Grout, which is a cement mortar used in the field of civil engineering and construction, is usually made by adding a water reducing agent to cement. Furthermore, calcium sulphoaluminate-based expansion materials, lime-based expansion materials, or foaming agents such as aluminum powder are added to make non-shrinkable materials, and river sand or silica sand are blended in these, and they are widely used. It is used to fill fine voids in concrete structures or voids in reverse construction, repair or reinforcement positions of structures, under the base plate of a mechanical device or under the track floor.

In general, cement mortar for filling construction in civil and construction works is called grouting. In grouting, there are prestressed concrete (PC) grouting, prepacked concrete grouting, backfill grouting for tunnels or shields, grouting for precast, and structure repair. Enhanced grouting, grouting of reinforced joints, grouting under bridge support, grouting under paving slabs, grouting under rails, and grouting under storage containers at nuclear power plants.

In recent years, the quality of concrete used in civil engineering and building structures has increased, and the properties required for cement mortars used as grouting have also required high flow and high strength depending on the application.
In order to obtain high fluidity or high strength performance, it is known to use cement, calcium aluminoferrite-based expansion material, silicon dioxide (SiO ₂ ) content of 90% or more, and hydrogen ion concentration in an acidic region. High-strength grouting mortar made of silica fine powder, polycarboxylic acid-based water reducing agent, and fine aggregate (see Patent Document 1).

In addition, in order to further obtain high fluidity or high strength expression, it is also known to use a water-soluble calcium salt in combination with an expansion material without using an expansion material, thereby providing a high-strength grouting mortar (see Patent Document 2).
However, the maximum compressive strength of these high-strength grouting mortars is only about 180 N / mm ² , and there is no high-strength grouting mortar that exhibits a strength of 200 N / mm ² or more.

Even if it is necessary to reduce the water / cement ratio of high-strength grouting mortar and improve the strength performance, it is necessary to use a large amount of water reducing agent to ensure the fluidity of the mortar. Therefore, there are cases in which not only the economic burden becomes large, but also many bubbles, Aggregate sedimentation hinders strength expression.

On the other hand, in order to reduce cracks in high-strength concrete, it has also been proposed to use coarse-grain cement having a Blaine specific surface area of 1000 cm ² / g to 2400 cm ² / g (Patent Document 3). However, with regard to cement that has been pulverized only in such a way that the Branson specific surface area becomes smaller, fine particles are not cut, and the water / cement ratio cannot be reduced when preparing concrete.

In order to prepare high-strength concrete, a hydraulic composition containing a binder including coarse-grained cement, β-1,3 glucan, and a high-performance water reducing agent has been proposed (Patent Document 4). This hydraulic composition uses coarse-grained cement in the range of 40 μm to 100 μm. However, it has the following problems: Due to the distorted particle size of the cement, the densest filling of the particles cannot be performed, and it is difficult to prepare a high particle size exceeding 100 N / mm ² . Strength concrete. In addition, there are problems in that material separation easily occurs and durability is hindered.
[Prior Art Literature]
[Patent Literature]

Patent Literature 1: Japanese Patent Laid-Open No. 2008-094675 Patent Literature 2: Japanese Patent Laid-Open No. 2010-150072 Patent Literature 3: Japanese Patent Laid-Open No. 2006-117439 Patent Literature 4: Japanese Patent Laid-Open No. 06-263506 Bulletin

[Problems to be Solved by the Invention]
Based on the foregoing, an object of the present invention is to provide a high-strength grouting material composition capable of ensuring fluidity even when kneaded at a low water / cement ratio, for example, exhibiting a compressive strength of 200 N / mm ² or more High-strength grouting mortar.

The present inventors have conducted various studies in order to solve the above-mentioned problems. As a result, they have found that by classifying cement and removing fine powder from the cement and combining it with a specific raw material, it is possible to obtain even a significantly reduced water / cement ratio. A high-strength grouting mortar capable of ensuring fluidity, for example, exhibiting a compressive strength of 200 N / mm ² or more, has completed the present invention.
[Means for solving problems]

That is, the present invention is (1) a high-strength grouting material composition, which is cement, pozzolan fine powder, containing 5 μm or less of particles with a content of 5% by mass or less, and a median diameter of 15 μm or more, Water-soluble calcium salt, water reducing agent, foaming agent, defoaming agent, and fine aggregate,
(2) A high-strength grouting material composition, wherein the content of particles of 5 μm to 40 μm of the cement is 75% by mass or more,
(3) A high-strength grouting material composition, wherein the pozzolan fine powder is a silica fine powder having a SiO ₂ content of 90% by mass or more, containing zirconia, and having a hydrogen ion concentration in an acidic region,
(4) A high-strength grouting material composition, wherein the pozzolan fine powder is 20 mass parts to 30 mass parts in a total of 100 mass parts of cement and pozzolan fine powder,
(5) A high-strength grouting material composition, wherein the water-soluble calcium salt is 0.2 parts by mass to 1 part by mass with respect to 100 parts by mass of the total of cement and pozzolan fine powder,
(6) A high-strength grouting material composition, wherein the fine aggregate is a heavy aggregate having a density of 3 g / cm ³ or more,
(7) A high-strength grouting material composition, wherein the fine aggregate is 60 to 100 parts by mass relative to 100 parts by mass of the total of cement and pozzolan fine powder,
(8) A high-strength grouting mortar, which is obtained by mixing the high-strength grouting material composition with water,
(9) A method for manufacturing a high-strength grouting mortar, comprising adding 15 to 18 parts by mass of water to 100 parts by mass of the high-strength grouting material composition and kneading.
[Effect of the invention]

By using the high-strength grouting material composition of the present invention, it is possible to provide a high-strength grouting mortar capable of ensuring fluidity even when kneaded at a low water / cement ratio, for example, exhibiting a compressive strength of 200 N / mm ² or more. .

Hereinafter, the present invention will be described in detail.
The parts or% used in the present invention are based on mass unless otherwise specified.

Examples of the cement of the present invention include various portland cements such as ordinary, early-strength, ultra-early-strength, low heat, and medium heat; or blast furnace slag and fly ash are mixed into these cements. Various cements made from silica or silica; filler cements made by mixing limestone powder or blast furnace slow-cooling slag fine powder, etc .; and environmentally coordinated types made from municipal waste ash or sewage sludge ash Cement (environmentally friendly cement).

In the cement of the present invention, the content of particles of 5 μm or less is 5% by mass or less, and the median particle diameter is 15 μm or more. Furthermore, the content of the particles of 5 μm to 40 μm is preferably 75% by mass or more. When the content of particles having a size of 5 μm or less exceeds 5 mass%, in addition to the inability to reduce the water / cement ratio, the viscosity during mortar kneading also increases, and the load becomes large. When the content of the particles of 5 μm to 40 μm is less than 75% by mass, the initial strength expression is deteriorated, and bleeding is liable to occur.
In addition, the content of particles of 5 μm or less, the median diameter, and the content of particles of 5 to 40 μm can be measured by the method described in the examples.

Cement with a content of 5 μm particles of 5% by mass or less and a median particle size of 15 μm or more generally includes 50 to 70 parts by mass of a C ₃ S solid solution, and 10 to 30 parts by mass of C ₂ S solid solution, 5 to 20 parts by mass of C ₃ A, 2 to 20 parts by mass of C ₄ AF, and 0.1 to 5 parts by mass of gypsum.
The Branson specific surface area is preferably in a range of 1500 cm ² / g to 3500 cm ² / g, and more preferably in a range of 1600 cm ² / g to 3000 cm ² / g.

Examples of the volcanic ash fine powder of the present invention include one or two or more kinds selected from blast furnace slag fine powder, fly ash, and silica fume.
In the present invention, in order to ensure good fluidity with a low water / cement ratio, it is preferable to use zirconia derived from zirconia having a SiO ₂ content of 90% by mass or more, containing zirconia, and having a hydrogen ion concentration in an acidic region. Silica fume.
The so-called hydrogen ion concentration mentioned here is that 20 g of silica ash is put into 100 g of pure water, and after stirring for 5 minutes with a magnetic stirrer, the hydrogen ion concentration (PH) of the suspension is measured by a pH meter. The value obtained.

As stipulated in Japanese Industrial Standards (JIS) A 6207, the so-called silica fume is spherical ultrafine particles containing amorphous silicon dioxide as the main component, and metal silicon is produced in an electric arc furnace or It is captured in the exhaust gas produced by ferrosilicon. In addition, the heat treatment conditions of the raw materials may be adjusted by a method of oxidizing the fine metal silicon powder in a flame or a method of melting the fine powder of the silicon dioxide raw material in a high-temperature flame, and the trapping temperature may be set to 550. Manufactured above ℃. In addition, there is also a so-called zirconia-derived silica fume. The zirconia-derived silica fume is collected by a cyclone or the like when the zircon sand is electrofused in an electric furnace. Made by classification.

In the present invention, it is preferable to use silica fume derived from zirconia. Zirconia-derived silica fume is a by-product of fused zirconia (zirconia ZrO ₂ ) used in the manufacture of refractory materials, grinding and grinding materials, electronic materials, and ceramic pigments. Exhaust dust generated during electrofusion of zircon sand (ZrSiO ₄ ) at ℃.
Its average particle diameter is about 1 μm, which is larger than silica ash with an average particle diameter of 0.1 μm to 0.3 μm captured in the exhaust gas generated when producing metallic silicon or ferrosilicon in an electric arc furnace.

The amount of the pozzolan fine powder used is preferably 20 to 30 parts out of the total 100 parts of the cement and the pozzolan fine powder. If it is less than 20 parts, the strength may be insufficient, or the load during kneading may increase. On the other hand, even if it exceeds 30 parts, the load during kneading may increase, and the flow may not be obtained with a predetermined amount of water. Sexual situation.

The water-soluble calcium salt of the present invention is used to obtain excellent fluidity. In general, examples of the water-soluble calcium salt include calcium acetate, calcium formate, and calcium nitrate. In the present invention, calcium acetate is preferably used.

In order to obtain excellent fluidity at a low water / cement ratio, it is also possible to use silica fume having a SiO ₂ content of 90% or more, containing zirconia, and having a hydrogen ion concentration in an acidic region, and a polycarboxylic acid-based water reducing agent. Achieved, but there are cases where a large amount of water reducing agent must be added depending on the type of cement. A large amount of the water-reducing agent adversely affects the initial strength expression. Therefore, in order to suppress the amount of the water-reducing agent being added to a certain range, a water-soluble calcium salt is also used.

The used amount of the water-soluble calcium salt is preferably 0.2 to 1 part, and more preferably 0.4 to 0.6 part based on 100 parts of the total of the cement and the pozzolan fine powder. If the content is less than 0.2 parts, the liquidity may be insufficient. On the other hand, if the content is more than 1 part, the liquidity may decrease.

The so-called water reducing agent of the present invention is a general term for those who have a dispersing effect on cement or an air-entraining effect, and improve fluidity or increase strength. Generally speaking, naphthalenesulfonic acid type water reducing agent and melamine sulfonic acid type water reducing Agent, lignosulfonic acid-based water reducing agent, and polycarboxylic acid-based water reducing agent.
Regarding the use form of the water reducing agent, both powder and liquid can be used, but when it is used as a premix product, powder is preferred.

The used amount of the water reducing agent is preferably 0.2 to 1 part, and more preferably 0.4 to 0.6 part based on 100 parts of the total of the cement and the pozzolan fine powder. When the content is less than 0.2 parts, the fluidity may be insufficient. On the other hand, when the content is more than 1 part, bubbles may be generated and the strength expression may be insufficient, or there may be a noticeable delay in coagulation.

The so-called foaming agent of the present invention is intended to make the mortar non-shrinkable, but to generate gas during kneading with water and obtain initial expansion.
The foaming agent is not particularly limited, and examples thereof include metal powder and peroxide. Among these, in terms of the amount of addition and the effect, aluminum powder is preferred. The surface of the aluminum powder is easily oxidized, and if it is covered with an oxide film, the reactivity decreases. Therefore, it is more preferable to use an aluminum powder that has been surface-treated with a vegetable oil, mineral oil, or stearic acid.

The use amount of the foaming agent is preferably 0.0003 to 0.002 parts, and more preferably 0.0005 to 0.0009 parts, based on 100 parts of the total of the cement and the pozzolan fine powder. If the content is less than 0.0003 parts, the foaming effect may not be sufficient. On the other hand, if it is more than 0.002 parts, foaming may be excessive and the strength may be reduced.

The so-called defoaming agent of the present invention has the effect of reducing the amount of air entrained during mortar kneading and improving the strength expression.
The defoaming agent is not particularly limited, and examples thereof include a polyoxyethylene alkyl ether-based defoamer and a Pluronic-based compound defoamer.

The use amount of the defoaming agent is preferably 0.02 to 0.2 parts, and more preferably 0.04 to 0.15 parts, based on 100 parts of the total of the cement and the pozzolan fine powder. If it is less than 0.02 parts, the defoaming effect may be insufficient and the strength performance may be adversely affected. On the other hand, even if it exceeds 0.2 parts, the effect may reach its limit and the economic burden may increase.

As the fine aggregate used in the present invention, a heavy aggregate is preferably used.
The heavy aggregate material is not particularly limited as long as it has fluidity retention properties, strength expression properties, and the like having a density of 3 g / cm ³ or more and crushed sand. Examples thereof include crushed sand such as magnetite, hematite, peridot, chromite slag, ferronickel slag, copper slag, and electric furnace oxidized slag. In the present invention, one kind of these may be used or two or more kinds may be used in combination. When used as a premix product, dry sand is preferably used.

The used amount of the fine aggregate is preferably 60 parts to 100 parts, and more preferably 70 parts to 90 parts with respect to 100 parts of the total of the cement and the pozzolan fine powder. If it is less than 60 parts, the self-shrinkage or dry shrinkage of the mortar may increase and cracks may easily occur. On the other hand, if it exceeds 100 parts, the fluidity or strength expression may be reduced.

The high-strength grouting mortar of the present invention is prepared by mixing the high-strength grouting material composition of the present invention described above with water. The high-strength grouting mortar is produced by, for example, adding 15 to 18 parts by mass of water to 100 parts by mass of the high-strength grouting material composition of the present invention and kneading them.

The amount of kneaded water in the present invention is preferably 15 to 18 parts with respect to 100 parts of the high-strength grouting material composition. Outside the range, the fluidity may be greatly reduced or the strength may be reduced.
In the present invention, the mixing method of the high-strength grouting material composition and water is not particularly limited, and it is preferable to use a hand mixer with a rotation speed of 900 rpm or more, a general high-speed grout mixer, or a biaxial type Forced mixer.

For kneading using a hand mixer or a high-speed grout mixer, for example, it is preferable to put predetermined water in a container or a mixer such as a tank, and then, while rotating the mixer, put in a high-strength grouting material composition and mix Refined for more than 3 minutes. In addition, as for the kneading by a forced mixer, for example, it is preferable that a high-strength grouting material composition is put into the mixer in advance, and a predetermined amount of water is added while the mixer is rotated, and the mixing is performed for at least 4 minutes. If the kneading time is less than a predetermined time, the fluidity of a suitable high-strength grouting mortar may not be obtained due to insufficient stirring.
The mixed high-strength grouting mortar is usually pressure-fed to the construction site and filled for construction by a manual injection gun, a diaphragm pump, or a squeeze pump.
[Example]

Hereinafter, the present invention will be described in detail by examples, but the present invention is not limited to these.

(Experimental example 1)
Cement (A) to cement (H) are used to produce a high-strength grouting material composition. At the time of preparation, among the total 100 parts of cement and pozzolan fine powder, 20 parts of pozzolan fine powder (1), and 0.5 parts of water-soluble calcium salt and 0.5 part of water reducing agent relative to 100 parts of total cement and pozzolan fine powder. , 0.0007 parts of foaming agent, 0.09 parts of defoaming agent, and 80 parts of fine aggregate (I). 16 parts of water was added to 100 parts of the high-strength grouting material composition and kneaded to prepare a high-strength grouting mortar, and the fluidity and compressive strength were measured. During the kneading, a hand mixer was used, and kneaded in a laboratory at a temperature of 20 ° C and a humidity of 60% for 5 minutes. The results are shown in Table 1.

(Materials used)
Cement (A): ordinary Portland cement, a commercially available product manufactured by Denka Co., Ltd., Bran's specific surface area of 3,200 cm ² / g, particle content of 5% or less, 28%, median particle size of 12 μm 5% to 40 μm particle content 61%
Cement (B): Graded Cement A, Bran's specific surface area of 2,400 cm ² / g, particle content of 5 μm or less, 5%, median particle size of 15 μm, 5 μm to 40 μm, particle content 75 %
Cement (C): Graded Cement A, with a Bran's specific surface area of 1,700 cm ² / g, a particle content of 5% or less, 3%, a median particle size of 19 μm, and a particle content of 5 to 40 μm 82 %
Cement (D): ordinary Portland cement prepared by using the same cement clinker as cement A and adding the same amount of gypsum. Brin's specific surface area of 1,700 cm ² / g, particle content of 5 μm or less, 6%, median particle diameter of 14 μm, particle content of 5 μm to 40 μm, 70%
Cement (E): Early-strength Portland cement, a commercially available product manufactured by Denka Co., Ltd., and a Blaine specific surface area of 4,500 cm ² / g. 37% particle size below 5 μm, 7 μm median particle size, 61% particle size from 5 μm to 40 μm
Cement (F): The product obtained by classifying cement E, with a Bran's specific surface area of 2,300 cm ² / g, a particle content of 5% or less, 4%, a median particle size of 15 μm, and a particle content of 5 to 40 μm, 85 %
Cement (G): Type B of blast furnace cement, a commercially available product manufactured by Denka Co., Ltd., Bran's specific surface area of 3,800 cm ² / g, particle content of 5% or less, 30% median particle size, 5 μm ～ 40 μm particle content 78%
Cement (H): Graded cement C, with a Branson specific surface area of 2,300 cm ² / g, a particle content of 5% or less, 4%, a median particle size of 17 μm, and a particle content of 5 to 40 μm84 %
Volcanic ash fine powder (1): silica fume, SiO ₂ content of 95.2%, pH (hydrogen ion concentration) = 2.90, containing zirconia, commercially available products

Water-soluble calcium salt: Calcium acetate water reducer: Polycarboxylic acid water reducer, commercially available product (manufactured by BASF, trade name: Melflux AP101F)
Foaming agent: aluminum powder, commercial product (product passing through a 100 mesh screen)
Defoaming agent: Polyoxyethylene alkyl ether-based defoaming agent, commercially available product (made by ADEKA, trade name: ADEKA NATE B115F)
Fine aggregate (I): nickel-iron slag, products with a density of 3.15 g / cm ³ and less than 1.5 mm, commercially available water: tap water

(experiment method)
Particle size distribution measurement: A laser diffraction device (HELOS & RODOS manufactured by Sympatec) was used to dry-disperse the sample and measure the particle size distribution. Thereby, the content of particles of 5 μm or less, the median diameter, and the content of particles of 5 μm to 40 μm were determined. The median particle diameter is a particle diameter at which the cumulative frequency becomes 50%.
Flowability: Static flow was measured in accordance with JIS R 5201 "Physical Test Method for Cement".
Compressive strength: Measured in accordance with Japan Society of Civil Engineering (JSCE) -G 505 "Compression strength test method for mortar or cement paste using cylindrical test specimens". After demolding at 1 day of age, maintenance was performed in water at 20 ° C, and measurements were performed at 28 and 56 days of age.

[Table 1]

(Experimental example 2)
Except having used cement (F) and changing the kind and addition amount of the pozzolan fine powder with respect to 100 parts of total cement and pozzolan fine powder, it carried out similarly to Experimental Example 1. The results are shown in Table 2.

(Materials used)
Pozzolan fine powder (2): blast furnace slag, density 2.92 g / cm ³ , specific surface area 11,090 cm ² / g, commercially available pozzolan fine powder (3): fly ash, density 2.27 g / cm ³ , specific surface area 3,526 cm ² / g, commercially available

[Table 2]

(Experimental example 3)
Except having used cement (F), and changing the addition amount of the water-soluble calcium salt with respect to 100 parts of total cement and pozzolan fine powder, it carried out similarly to Experimental Example 1. The results are shown in Table 3.

[table 3]

(Experimental Example 4)
Except having used cement (F), and changing the addition amount of the water-reducing agent with respect to 100 parts of the total amount of cement and pozzolan fine powder, it carried out similarly to Experimental Example 1. The results are shown in Table 4.

[Table 4]

(Experimental example 5)
Except for using cement (F), the addition amount of the foaming agent to 100 parts of the total of the cement and the pozzolan fine powder was changed, and the expansion and contraction rate was measured. The results are shown in Table 5.

(experiment method)
Swelling and shrinkage rate: Measured in accordance with the Japanese Society of Civil Engineers JSCE-F 533 "Test Method for Water Leakage Rate and Compressive Strength of PC Grouting". Measurement value of 1 day of age.

[table 5]

(Experimental example 6)
Except having used cement (F), and changing the addition amount of the defoaming agent with respect to 100 parts of the total amount of cement and pozzolan fine powder, it carried out similarly to Experimental Example 1. The results are shown in Table 6.

[TABLE 6]

(Experimental Example 7)
Except for using cement (F), the addition amount and type of the fine aggregate with respect to 100 parts of the total amount of the cement and the pozzolan fine powder were changed, and the length change was measured. The results are shown in Table 7.

(Materials used)
Fine aggregate (II): silica sand, products with a density of 2.60 g / cm ³ and less than 1.5 mm, commercially available products

(experiment method)
Length change: Measured in accordance with JIS A 1129-3 "Test method for length change of mortar and concrete-Part 3: Dial gauge method". The temperature was maintained at a temperature of 20 ° C and a humidity of 60% until the age of the wood was 28 days, and the length change was measured.

[TABLE 7]

(Experimental Example 8)
Except that 100 parts of the high-strength grouting material composition of Experimental Example 1-6 was changed, the addition amount of water was changed to produce a high-strength grouting mortar, and the same procedure was performed as in Experimental Example 1. The results are shown in Table 8.

[TABLE 8]


[Industrial availability]

By using the high-strength grouting material composition of the present invention, it is possible to obtain a high-strength grouting mortar that can maintain fluidity even when kneaded at a low water / cement ratio and exhibits a compressive strength of 200 N / mm ² or more.

Claims (9)

A high-strength grouting material composition, which is a cement, pozzolan fine powder, water-soluble calcium salt, water reducing agent, and foaming agent containing 5 μm or less of particles having a content of 5 μm or less and a median particle size of 15 μm or more , Defoamer, and fine aggregate. The high-strength grouting material composition according to item 1 of the scope of patent application, wherein the content of particles of 5 μm to 40 μm of the cement is 75% by mass or more. The high-strength grouting material composition according to item 1 or item 2 of the patent application scope, wherein the pozzolan fine powder is the _second one having a SiO ₂ content of 90% by mass or more, containing zirconia, and a hydrogen ion concentration in an acidic region. Silica fine powder. The high-strength grouting material composition according to any one of claims 1 to 3, wherein the pozzolan fine powder is 20 parts by mass to 100 parts by mass of the cement and the pozzolan fine powder in total. 30 parts by mass. The high-strength grouting material composition according to any one of claims 1 to 4, wherein the water-soluble calcium salt is 0.2 mass based on 100 mass parts of the cement and pozzolan fine powder in total. Parts to 1 part by mass. The high-strength grouting material composition according to any one of claims 1 to 5, wherein the fine aggregate is a heavy aggregate having a density of 3 g / cm ³ or more. The high-strength grouting material composition according to any one of claims 1 to 6, wherein the fine aggregate is 60 parts by mass relative to 100 parts by mass of the cement and pozzolan fine powder in total. ~ 100 parts by mass. A high-strength grouting mortar is prepared by mixing the high-strength grouting material composition according to any one of claims 1 to 7 of the patent application scope with water. A method for manufacturing a high-strength grouting mortar, comprising adding 15 to 18 parts by mass of water to 100 parts by mass of the high-strength grouting material composition according to any one of claims 1 to 7 of the scope of patent application. And knead.