JPH10101390A - Curing accelerator, spraying material and spraying method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curing accelerator and a spraying material free from the ill effect on working environment or surrounding environment, improved in the adhesion and the curing accelerating property of a concrete and used for spraying on a tunnel or the like. SOLUTION: The curing accelerator uses a calcium aluminate glass or an aluminosilicate calcium glass, aluminum sulfate and a borazon material as available components. In the curing accelerator, the borazon material is composed of one or more kinds selected from a group composed of a silica fume, a metakaoline, a blast furnace slag and a fly ash. The spraying material uses cement and the curing accelerator as available components. A spraying concrete uses the spraying material as an available component and a spraying method is by spraying the spraying concrete.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quick setting material, a spraying material, and a spraying method using the same, and more particularly, to an adhesive property and a quick setting property of concrete sprayed on a ceiling or a wall portion such as a tunnel or a shaft. The present invention relates to an increased quick setting material, a spray material, and a spray method using the same.

[0002] In the present invention, sprayed concrete is a general term for sprayed cement paste, mortar, and concrete.

[0003]

2. Description of the Related Art Conventionally, it has been generally practiced to spray shot concrete or the like during excavation of a tunnel and lining it to prevent collapse of the excavated surface due to falling surface or spring water. In tunnel construction, the primary spraying of sprayed concrete on the excavation surface was often performed, and the secondary lining was often performed on the sprayed surface with concrete walls. The single shell method, which is completed only by itself, tends to be widely adopted.

[0004] The spraying method of sprayed concrete is roughly classified into two methods, a dry spraying method and a wet spraying method. The dry spraying method is a method of transporting a mixture of cement, aggregate, and quick-setting material that has been pulverized by compressed air, adding and mixing water immediately before spraying, and spraying the work surface from a nozzle by wet spraying. The law is
In this method, concrete kneaded with water is transported by wheel, a quick-setting material is added and mixed on the way, and sprayed from a nozzle.

[0005] As a quick setting material used for spraying, a composition comprising calcium aluminate and an alkali metal carbonate or aluminate, a composition comprising calcined alumite, lime and an alkali metal carbonate And compositions comprising alkali metal carbonates, hydroxides, silicates and aluminates have been proposed (JP-B-56-27457, JP-A-60-260452, etc.). . These quick-setting materials are
Usually, in order to obtain a rapid setting, it contains a strongly alkaline alkali metal component such as sodium or potassium in the form of hydroxide, carbonate, silicate and aluminate. Since these alkali metal components are strongly alkaline, when they are contained in shotcrete, there is a problem that an alkali-aggregate reaction occurs depending on the aggregate used, which adversely affects the concrete structure.

[0006] These strongly alkaline substances dissolve in water and have the property of causing severe chemical injury when they come into direct contact with the skin of an operator, which significantly deteriorates the working environment at the excavation site and is contained in the soil. There were problems such as dissolving in water and causing environmental pollution in the surrounding area.

As a measure to solve these problems, a setting accelerator comprising calcium aluminate, calcium sulfoaluminate, a basic aluminum salt or the like is used as a quick-setting material for spraying which contains little or no alkali component. It has been proposed to divert (Japanese Unexamined Patent Publication No.
No. 48553). However, there is a problem that these quick-setting materials have insufficient quick-setting properties and that the sprayed shot concrete rebounds, that is, has a large amount of rebound, so that a large amount of material is lost and dust is easily generated.

As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that by using a specific quick-setting material,
The inventors have found that a shotcrete exhibiting excellent quick-setting characteristics can be obtained without deteriorating the working environment and the surrounding environment, and have completed the present invention.

[0009]

That is, the present invention is a quick-setting material containing calcium aluminate glass or calcium aluminosilicate glass, aluminum sulfate, and a pozzolanic substance as active ingredients, wherein the pozzolanic substance is silica fume. , Metakaolin, blast furnace slag, and a quick-setting material of one or more selected from the group consisting of fly ash, a spray material containing cement and the quick-setting material as active ingredients, the spray material A spraying method comprising spraying concrete as an active ingredient, and spraying the spraying concrete.

Hereinafter, the present invention will be described in detail.

The quick-setting material according to the present invention comprises calcium aluminate glass or calcium aluminosilicate glass,
It contains aluminum sulfate and a pozzolanic substance as active ingredients.

Calcium aluminate used in the present invention
Glass (hereinafter referred to as CA glass)
Required, usually CaO raw material and Al_TwoO_ThreeMix the raw materials
For example, at a high temperature of about 1,200 to 1,700 ° C
Generated, for example, 3CaO.Al _TwoO_Three, 12CaO ・ 7Al_TwoO_Three,
And CaO ・ Al_TwoO_ThreeCalcium aluminate ore
It is a vitrified product obtained by rapidly cooling a molten material. Also,
The calcium aluminosilicate glass used in the present invention (hereinafter referred to as “aluminosilicate glass”)
Lower CAS glass) is usually CaO raw material, Al_TwoO_Threeoriginal
Material and SiO_TwoAluminoke produced similarly by mixing the raw materials
Calcium iate mineral melt was quenched and vitrified
Therefore, it is better to use CAS than CA glass because of its excellent quick setting.
The use of glass is preferred. Calcium aluminate or
Method of quenching melt of calcium aluminosilicate mineral
To blow off the melt with high-pressure air and allow it to cool
There is a high pressure air method and the like.

[0013] As the CaO material, quicklime, slaked lime, limestone, and calcium carbonate and the like, also, as the Al ₂ O ₃ raw material, aluminum oxide, bauxite, Daiasuboa,
Feldspar, and clay, etc., further, as the SiO ₂ raw material, silica sand, terra alba, diatomaceous earth, silicon oxide, etc. can be used, respectively, but calcium carbonate and aluminum oxide, The use of silicon oxide is preferred. The CaO content in the CA glass is preferably 35 to 55% by weight. If the CaO content is outside this range, good quick-setting properties may not be obtained. The composition of the CAS glass is
CaO is 40-50 wt%, Al ₂ O ₃ is 40 to 50 wt%, and SiO ₂
Is preferably 10 to 20% by weight. If CaO or Al ₂ O ₃ is out of this range, good quick-setting properties may not be obtained.
If the content of SiO ₂ is less than 10% by weight, the long-term strength may not elongate, and if it exceeds 20% by weight, the initial strength may be low.

The glass referred to in the present invention is "a glass exhibiting a glass transition point" generally referred to in the field of glass. It is not necessary that all of the CA glass or the CAS glass (hereinafter collectively referred to as a CA glass) be a glass, and the vitrification ratio indicating the degree thereof may be 60% or more. If it is less than 60%, good quick-setting properties may not be obtained. The vitrification rate depends on the sample
After heating at 1,000 ° C. for 2 hours, the mixture was gradually cooled at a cooling rate of 5 ° C./min, and the area So of the main peak of the crystalline mineral was determined by powder X-ray diffraction.
It can be determined from S by the formula of vitrification rate (%) = (1−S / So) × 100. The particle size of the CA-based glass is not particularly limited, but the Blaine value is 3,000 to 9,000 cm ² / g.
Is preferred. If it is less than 3,000 cm ² / g, good quick-setting properties may not be obtained, and if it exceeds 9,000 cm ² / g, further effects may not be expected.

The aluminum sulfate used in the present invention is necessary for improving quick-setting properties, and generally commercially available aluminum sulfate can be used, and is not affected by impurities usually contained. In addition, although aluminum sulfate contains an anhydrous salt and water of crystallization, all of them can be used as they are and are not limited by the amount of water of crystallization. The particle size of aluminum sulfate is not particularly specified, but is preferably in the range of 3,000 to 9,000 cm ² / g in Blaine value. If it is less than 3,000 cm ² / g, good quick-setting properties may not be obtained, and if it exceeds 9,000 cm ² / g, further effects may not be expected. The amount of aluminum sulfate used is
20 to 50 parts by weight, preferably 30 to 40 parts by weight, based on 100 parts by weight of the CA glass. Outside this range, good quick-setting properties may not be obtained.

The pozzolanic substance used in the present invention is a substance containing a reactive silicic acid which hardens by reacting with calcium hydroxide, for example, artificial ones such as silica fume, metakaolin, blast furnace slag and fly ash. There are natural substances such as diatomaceous earth and volcanic ash, and in the present invention, use of one or more pozzolanic substances selected from the group consisting of silica fume, metakaolin, blast furnace slag, and fly ash has a quick setting property. This is preferable from the viewpoint of improving the repellency and reducing the rebound of sprayed concrete.

The silica fume used in the present invention is called silica flour, silica dust, micro silica, or the like, and is used as a deoxidizing agent or a desulfurizing agent in producing steel, or an alloy element is added to steel. This is an industrial by-product produced during the production of ferroalloys such as ferrosilicon used for this purpose and metallic silicon as a raw material for various materials. Ferrosilicon and metallic silicon are manufactured from silica stone or high-purity quartz, iron shavings, carbon or coal as a reducing agent, and heated to a high temperature near 2,000 ° C in an electric furnace. Silicon oxide generated as an intermediate product is gasified, a part of which is scattered in the air, oxidized in an exhaust duct, and SiO ₂ collected by a dust collector is silica fume, which is spherical ultrafine particles. The chemical composition of silica fume varies depending on the raw material used, the production method, the type of main product, and the like, but the main component is amorphous SiO ₂ , and the content of SiO ₂ is preferably at least 80% by weight. Further, specific gravity about 2.L～2.2, a bulk specific gravity of 250~300kg / m ³ approximately, fineness BET specific surface area 15,000 to 25,000 m ² / kg approximately,
And those having an average particle size of about 0.1 to 0.2 μm can be used. The amount of the silica fume used is preferably 50 to 200 parts by weight based on 100 parts by weight of the CA glass, and 100 to 150 parts by weight.
Parts by weight are more preferred. Outside this range, good quick-setting properties may not be obtained.

The metakaolin used in the present invention is obtained by baking kaolinite at 500 to 600 ° C. to make the main components SiO ₂ and Al ₂ O ₃ amorphous. The particle size of the metakaolin is preferably 4,000 cm ² / g or more in Blaine value, 6,000 ² / g or more is more preferable. If it is less than 4,000 cm ² / g, good quick-setting properties may not be obtained. Metakaolin is used in an amount of 50 to 20 with respect to 100 parts by weight of CA glass.
0 parts by weight is preferable, and 100 to 150 parts by weight is more preferable. Outside this range, good quick-setting properties may not be obtained.

The blast furnace slag used in the present invention is obtained by rapidly cooling molten slag by-produced when pig iron is produced from iron ore in a blast furnace with water, air, or the like to pulverize or pulverize the slag.
It is a fine powder mainly composed of aluminosilicate obtained by classification. Blast furnace slag consists of CaO, SiO ₂ , Al ₂ O ₃ , and M
gO, CaO / SiO ₂ = 1.15-1.25, (CaO + MgO) / (S
It is preferred that iO ₂ + Al ₂ O ₃ ) = 0.90 to 1.05, Al ₂ O ₃ be less than 15% by weight, and MgO be less than 5% by weight. The grain size of the blast furnace slag is preferably 4,000 cm ² / g or more as a Blaine value,
000 cm ² / g or more is more preferable. If it is less than 4,000 cm ² / g, good quick-setting properties may not be obtained. The amount of the blast furnace slag is preferably 50 to 200 parts by weight, more preferably 100 to 150 parts by weight, based on 100 parts by weight of the CA glass. Outside this range, good quick-setting properties may not be obtained.

The fly ash used in the present invention, when the combustion of pulverized coal, which was collected by the electrostatic precipitator or the like which molten ash becomes cooled by spherical, a SiO ₂ 60
% Or more, and may also contain Al ₂ O ₃ , Fe ₂ O ₃ and carbon. The fly ash preferably has a Blaine value of 3,000 to 6,000 cm ² / g. If it is less than 3,000 cm ² / g, good quick setting may not be obtained, and 6,000 cm ² / g
In some cases, further effects cannot be expected. The amount of fly ash used is preferably 50 to 200 parts by weight, more preferably 100 to 150 parts by weight, based on 100 parts by weight of the CA glass. Outside this range, good quick-setting properties may not be obtained.

The total amount of alkali metals in the quick-setting material is preferably 0.75% by weight or less in terms of sodium oxide (Na ₂ O). If the content exceeds 0.75% by weight, an alkali-aggregate reaction occurs, which may adversely affect concrete structures. The particle size of the quick-setting material is not particularly limited because it depends on the purpose of use and the method of use, but usually, the Blaine value is 3,000 to 9,000 cm ²
/ g is preferred. If it is less than 3,000 cm ² / g, quick-setting properties may decrease, and if it exceeds 9,000 cm ² / g, further effects cannot be expected. The amount of the quick setting material is preferably 5 to 20 parts by weight, and more preferably 8 to
15 parts by weight is more preferred. Outside this range, good quick-setting properties may not be obtained.

Here, the cement is not particularly limited, and various portland cements, such as ordinary, fast and super fast, which are usually used, can be used.

The quick-setting and spraying materials according to the present invention include, for example, a setting modifier, an AE agent, a water reducing agent, an AE water reducing agent, a fluidizing agent, a thickener, a water retaining agent, a waterproofing agent, a foaming agent, Foaming agents, water-immiscible admixtures such as methylcellulose, antifreeze agents, antirust agents,
Coloring agents (pigments), calcium-containing compounds such as calcium hydroxide, polymer emulsions (latex),
Fiber materials such as glass fiber, carbon fiber, and steel fiber,
In addition, one or more additives such as silica sand, natural sand, and aggregates such as gravel can be used in combination as long as the object of the present invention is not hindered.

In producing the quick setting material and the spraying material of the present invention, for example, existing mixing and stirring devices such as a tilting mixer, an omni mixer, a V-type mixer, a Henschel mixer and a Nauta mixer can be used. It is. The mixing may be performed by mixing the respective materials at the time of construction or by mixing a part or all of the materials in advance. Further, the curing method is not particularly limited, and a generally performed curing method is applicable.

The spraying material of the present invention can be used for both dry spraying and wet spraying. For example, at the time of spraying, it is possible to use a coarse aggregate having a maximum aggregate size of about 10 mm, a concrete ratio of water / (cement + rapidly set) of 45%, and a fine aggregate ratio of 60%. Also, as a wet spraying method,
For example, concrete obtained by mixing water, cement, coarse aggregate and fine aggregate with a mixer is pumped using a spraying machine that can air-pump at 10 to 20 m ³ / hr, or a compressor is used separately for quick-setting material And spraying by mixing with concrete near the nozzle of the spraying machine.

[0026]

The present invention will be described below in detail with reference to examples.

Example 1 A CaO raw material and an Al ₂ O ₃ raw material, or a mixture of a CaO raw material, an Al ₂ O ₃ raw material, and a SiO ₂ raw material, were quenched in an electric furnace at 1600 ° C., and rapidly cooled by a high-pressure air method. , Further crushed, Brain value
5,000 ± 200 cm ² / g CA-based glass shown in Table 1 was prepared. 100 parts by weight of the prepared CA glass, 35 parts by weight of aluminum sulfate α, and 125 parts by weight of a pozzolanic substance were mixed to prepare a quick-setting material, and an alkali metal component in the quick-setting material was analyzed. Table 2 shows the results. A spraying material was manufactured by mixing 10 parts by weight of the quick setting material and cement in 100 parts by weight of the spraying material comprising the cement A and the quick setting material. 700 g of the produced spraying material and 2,100 g of fine aggregate are mixed and kneaded at low speed for 30 seconds using a small table-top mortar mixer.
0 g was added and kneaded at a high speed for 10 seconds to obtain a cement mortar, and its setting property was evaluated by a proctor penetration resistance value.
The results are also shown in Table 2. For comparison, a similar procedure was performed using a commercially available quick setting material instead of the quick setting material of the present invention.
The results are also shown in Table 2.

<Materials> CaO raw material: calcium carbonate, commercially available Al ₂ O ₃ raw material: aluminum oxide, commercially available SiO ₂ raw material: silicon oxide, commercially available aluminum sulfate α: anhydrous, Na ₂ Oeq. 0.04% by weight pozzolan Material: silica fume, ferrosilicon production by-product, specific gravity 2.20, specific surface area 21.9m ² / g, Na ₂ Oeq. 1.4% by weight Commercial quick-setting material: main component calcium aluminate, Na ₂ Oeq
_. 15.8% by weight of the cement A: ordinary Portland cement, Blaine value 3,
300cm ² / g, Na ₂ Oeq. 0.48% by weight Fine aggregate: Himekawa river sand from Niigata prefecture, specific gravity 2.62 Water: Tap water

<Measurement method> Alkali metal: Measured by atomic absorption analysis. Alkali metals other than sodium were converted to Na ₂ O and integrated to obtain Na ₂ Oeq. Proctor penetration resistance: in a thermostatic chamber at a temperature of 20 ° C., kneaded, and immediately divided into two layers into a mold, filled quickly while pushing a stick thrust mortar, a predetermined time after injection, needle point area 1 / 40in ²
Measured according to ASTM C403-65T using a needle.

[0030]

[Table 1]

[0031]

[Table 2]

Example 2 100 parts by weight of the prepared CA glass, aluminum sulfate α
A quick-setting material was prepared by mixing 35 parts by weight and 125 parts by weight of a pozzolanic substance, and an alkali metal component in the quick-setting material was analyzed. Table 3 shows the results. A spraying material was manufactured by mixing 10 parts by weight of the quick setting material and cement in 100 parts by weight of the spraying material comprising the cement A and the quick setting material. Sprayed material 70 manufactured
0 g, 2,100 g of fine aggregate, using a small tabletop mortar mixer, kneading at low speed for 30 seconds, then adding 280 g of water and kneading at high speed for 10 seconds to make cement mortar,
The coagulation characteristics were evaluated by the proctor penetration resistance value. The results are also shown in Table 3.

<Materials used> Pozzolanic substance: blast furnace slag, Blaine value 8,000 cm ² / g,
Na ₂ Oeq. 0.55% by weight

[0034]

[Table 3]

Example 3 The same procedure as in Example 1 was carried out except that 100 parts by weight of a CA glass shown in Table 4 and aluminum sulfate α and 125 parts by weight of a pozzolanic substance shown in Table 4 were used. The results are also shown in Table 4.

[0036]

[Table 4]

Example 4 The procedure of Example 2 was repeated except that 100 parts by weight of CA glass n, aluminum sulfate α shown in Table 5 and 125 parts by weight of a pozzolanic substance were used. The results are also shown in Table 5.

[0038]

[Table 5]

Example 5 The procedure of Example 1 was repeated except that 100 parts by weight of the CA glass shown in Table 6, 35 parts by weight of aluminum sulfate α, and 125 parts by weight of the pozzolanic substance shown in Table 6 were used. The results are also shown in Table 6. <Materials> Pozzolanic substance: metakaolin, average particle size 3.2 μm, Na
₂ Oeq. 0.30% by weight Pozzolanic substance: Blast furnace slag, Blaine value 6,000cm ² / g,
Na ₂ Oeq 0.51 wt% pozzolanic materials:. Blast furnace slag, Blaine value 4,000 cm ² / g,
Na ₂ Oeq 0.50 wt% pozzolanic materials:. Fly ash, Blaine value 4,000 cm ²
/ g, Na ₂ Oeq. 1.40% by weight

[0040]

[Table 6]

Example 6 The procedure of Example 2 was repeated except that 100 parts by weight of CA glass, 35 parts by weight of aluminum sulfate β, and 125 parts by weight of the pozzolanic substance shown in Table 7 were used. Performed similarly. Table 7 shows the results.

<Materials used> Aluminum sulfate β: 14-18 hydrate, primary reagent, Na ₂ Oeq.
0.04% by weight

[0043]

[Table 7]

Example 7 The procedure of Example 1 was repeated except that 100 parts by weight of the CA glass shown in Table 8, 35 parts by weight of aluminum sulfate α, and the pozzolanic substance shown in Table 8 were used. The results are also shown in Table 8.

[0045]

[Table 8]

Example 8 The same procedure as in Example 2 was carried out except that 100 parts by weight of CA glass n, 35 parts by weight of aluminum sulfate α, and pozzolanic substances shown in Table 9 were used. The results are also shown in Table 9.

[0047]

[Table 9]

Example 9 Example 1 was repeated using 100 parts by weight of CA glass b, 35 parts by weight of aluminum sulfate α, and 125 parts by weight of a pozzolanic substance.
A quick-setting material was prepared in the same manner as described above. Na ₂ O eq. In quick-setting material is 0.69
%Met. The procedure was performed in the same manner as in Example 1 except that the quick setting material and the cement shown in Table 10 were used. Table 1 shows the results
0 is also added.

<Materials Used> Cement B: Moderate heat Portland cement, Blaine value
3,100cm ² / g, Na ₂ O eq. 0.46% by weight Cement C: Portland cement with high strength, Blaine value of 4,
400cm ² / g, Na ₂ O eq. 0.43% by weight

[0050]

[Table 10]

Example 10 Example 2 was repeated using 100 parts by weight of CA glass n, 35 parts by weight of aluminum sulfate α, and 125 parts by weight of a pozzolanic substance.
A quick-setting material was prepared in the same manner as described above. Na ₂ O eq. In quick-setting material is 0.69
%Met. The procedure was performed in the same manner as in Example 2 except that the quick setting material and the cements shown in Table 11 were used. Table 1 shows the results
Also described in 1.

[0052]

[Table 11]

Example 11 A quick-setting material was prepared in the same manner as in Example 1 using 100 parts by weight of the CA glass, 35 parts by weight of aluminum sulfate α, and 125 parts by weight of a pozzolanic substance shown in Table 12. The Na ₂ O eq. In the prepared quick-setting material was 0.69%. This quick-setting material was used in the same manner as in Example 1 except that 100 parts by weight of the spray material was used, as shown in Table 12. The results are shown in Table 12.

[0054]

[Table 12]

Example 12 Example 2 was repeated using 100 parts by weight of CA glass n, 35 parts by weight of aluminum sulfate α, and 125 parts by weight of a pozzolanic substance.
A quick-setting material was prepared in the same manner as described above. Na ₂ O e in prepared quick-setting material
q. was 0.69%. Example 2 was repeated except that the quick-setting material was used in parts by weight shown in Table 13 out of 100 parts by weight of the spray material.
The same was done. The results are shown in Table 13.

[0056]

[Table 13]

Example 13 In 100 parts by weight of the spray material, 7 quick-setting materials having the composition shown in Table 14 were used.
Parts by weight, the unit amount of each material is Cement A 360kg / m ³ ,
Fine aggregate 1,130kg / m ^3, the coarse aggregate 756kg / m ^3, and water 162 kg / m ^3, the maximum aggregate size 10 mm, the concrete produced in fine aggregate ratio of 60% of the concrete mix, dry sprayer or Using a wet spraying machine, spraying was performed in a simulated tunnel having a height of 3.5 m and a width of 3 m, and the amount of rebound of concrete dropped into the tunnel was measured as a rebound rate. The results are shown in Table 14.

<Materials used> Coarse aggregate: Gravel from Himekawa, Niigata Prefecture, specific gravity 2.66

<Measurement method> Rebound ratio: The ratio of the amount of material used for spraying to the amount of rebound of concrete that has fallen without adhering when sprayed.

[0060]

[Table 14]

Example 14 n100 parts by weight of CA glass, aluminum sulfate α, and the amount of pozzolanic substance or fly ash i shown in Table 15
Was carried out in the same manner as in Example 13 except that a quick setting material mixed with was used. The results are shown in Table 15.

[0062]

[Table 15]

[0063]

The quick-setting material of the present invention has a small amount of alkali metal, so that it has no adverse effect on the working boundary and the surrounding environment, and has excellent quick-setting characteristics.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 28/02 C04B 28/02 E21D 11/10 E21D 11/10 D // C04B 103: 12 111: 20

Claims (6)

[Claims] 1. A quick setting material containing calcium aluminate glass, aluminum sulfate, and a pozzolanic substance as active ingredients. 2. A quick setting material comprising calcium aluminosilicate glass, aluminum sulfate, and a pozzolanic substance as active ingredients. 3. The quick-setting material according to claim 1, wherein the pozzolanic substance is at least one member selected from the group consisting of silica fume, metakaolin, blast furnace slag, and fly ash. 4. A spray material comprising cement and the quick-setting material according to claim 1 as active ingredients. 5. A sprayed concrete comprising the sprayed material according to claim 4 as an active ingredient. 6. A method for spraying shotcrete, comprising spraying the shotcrete according to claim 5.