JP2002249361A - Spray material and spray technique using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spray material giving a spray structure, which has small amount of dust, small amount of mist and small rebound, enhances long-term strength and excels in durability. SOLUTION: The spray material contains a hydraulic material of 100 pts.wt., aggregate of 150 to 300 pts.wt., polymer emulsion, cement concrete having water and a quick setting admixture having aluminium sulfate. The spray material may include fiber, a viscosity modifier and fine powder. The quick setting admixture may include alkali metal carbonates and is preferably liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to prevent the ground surface and the slope where the ground is exposed from collapsing in tunnel excavation work for roads, railways, and headraces, and to prevent concrete structures from being collapsed. The present invention relates to a spray material used for repairing the like. In the present invention, mortar and concrete are collectively referred to as cement concrete, cement concrete containing no water is called dry cement concrete, and cement concrete containing water is called wet cement concrete.

[0002]

2. Description of the Related Art Conventionally, in the excavation of tunnels for roads and railways, a spraying method using a quick-setting concrete mixed with a quick-setting agent and concrete as a spraying material is used in order to prevent the exposed ground surface from collapsing. It has been implemented. In this method, concrete is usually prepared by mixing cement, aggregate, and water in a concrete manufacturing facility installed at the construction site, transported to the spraying site by an agitator truck, and air-conveyed by a spraying machine. The NATM method in which a quick-setting agent conveyed by air from one of the mixing pipes provided on the way is combined and mixed, and is sprayed as quick-setting spray concrete.

In the after-blowing after excavation by the TBM method, wet mortar is prepared by continuously mixing dry mortar in which a hydraulic material and an aggregate are previously mixed with water by a mixer pump of a continuous kneading type, and is fed and pumped. Then, a method of mixing and mixing with a liquid quick-setting admixture and spraying as a quick-setting spray mortar has been implemented.

In spraying on a slope, a liquid quick-setting agent mainly composed of water glass is combined with concrete to prevent dripping of the mortar sprayed by the free frame method, and the quick-setting spray concrete is obtained. The spraying method has been implemented.

[0005]

In such various conventional spraying methods, for example, in a method of excavating tunnels for roads and railways, a powder quick-setting agent is generally used. Dust may degrade the working environment. Therefore, there has been a problem that the protection against dust has to be sufficient and the workability deteriorates.

[0006] In recent years, early deterioration of concrete has become a problem, and there is a demand for quick-setting shotcrete to have improved durability such as freeze-thaw resistance, neutralization resistance, and drying shrinkage resistance. I have. Therefore, it is necessary to improve the quality of quick-setting sprayed concrete. However, using conventional quick-setting spray concrete,
A relatively large increase of about 0.1 to 3 mm increases the ratio of the voids in the quick-setting sprayed concrete compared to the shotcrete that does not use the quick-setting agent, so that the durability may decrease. there were.

As a result of various studies to solve these problems, the inventor of the present invention has found that the use of a specific spraying material can solve the problems and has completed the present invention.

[0008]

That is, the present invention provides a cement concrete containing 100 parts by mass of a hydraulic material, 150 to 300 parts by mass of an aggregate, a polymer emulsion and water, and aluminum sulfate. A spraying material comprising a quick-setting agent, further comprising: a spraying material comprising fine powder; and a spraying material comprising a viscosity modifier, further comprising a fiber. The sprayed material having a particle size of 3000 cm ^{2 in} Blaine value.
/ G or more, wherein the quick-setting agent is a liquid quick-setting agent. Then, the cement concrete containing 100 parts by mass of the hydraulic material, 150 to 300 parts by mass of the aggregate, the polymer emulsion, and water is pumped, and the quick-setting agent containing aluminum sulfate is mixed and mixed during the pumping. To prepare quick-setting cement concrete,
This is a spraying method characterized by spraying.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The present invention provides a cement concrete by kneading a hydraulic material, a specific amount of aggregate, a polymer emulsion, and water, and mixing and setting a quick-setting agent to the cement concrete. A cement concrete is prepared, and this quick-setting cement concrete is sprayed as a spray material. In particular, the polymer emulsion improves the fluidity, adhesion, freeze-thaw resistance, neutralization resistance, and drying shrinkage resistance, and enables dust, mist,
In addition, it has an effect of being low in rebound and being excellent in initial and long-term strength development.

Examples of the hydraulic material used in the present invention include cements, mixtures of cements and calcium sulfoaluminates, and mixtures of cements, calcium sulfoaluminates, and gypsum.
Among them, a mixture of cements and calcium sulfoaluminates is preferable in terms of excellent initial strength development and reaction activity.

[0012] As cements, various Portland cements such as ordinary, fast, moderate heat, super fast, and low heat, etc.
Various mixed cements in which fly ash, blast furnace slag, and the like are mixed with these Portland cements, fine particle cements, and the like are given.

The calcium sulfoaluminates used in the present invention include those obtained by sintering free lime and anhydrous gypsum. Calcium aluminates may be used instead of calcium sulfoaluminates.

Among the calcium sulfoaluminates
Is superior in drying shrinkage resistance, _FourA_ThreeSO_Three(still,
C stands for CaO, A for Al_TwoO_ThreeIs preferable.

The particle size of the calcium sulfoaluminates is preferably 2000 cm ² / g or more, more preferably 3000 cm ² / g or more in terms of reactivity, in terms of Blaine value. If it is less than 2000 cm ² / g, the reactivity may be low and sufficient effect may not be exhibited.

The amount of the calcium sulfoaluminate to be used is preferably 0.5 to 8 parts by mass, more preferably 2 to 7 parts by mass, based on 100 parts by mass of the cement. If the amount is less than 0.5 part by mass, it is difficult to promote the initial setting, and it is difficult to promote the improvement of the drying shrinkage resistance. If the amount exceeds 8 parts by mass, the fluidity of the cement concrete may be impaired.

The aggregate used in the present invention includes river sand, mountain sand, sea sand, lime sand and the like. Aggregate may be used by mixing with hydraulic material or water at the spraying site, or the dried aggregate is mixed with hydraulic material to form a premix type dry cement concrete, and this dry cement Concrete may be transported to the site.

The particle size of the aggregate is 2.5 mm in terms of pumpability and the like.
Or less, more preferably 1.5 mm or less. 2.5
If it exceeds mm, the pumpability will decrease and the rebound rate when sprayed may increase.

The amount of the aggregate used is 150 to 300 parts by mass with respect to 100 parts by mass of the hydraulic material, and 180 to 27 parts by mass.
0 parts by mass is preferred. If the amount is less than 150 parts by mass, the drying shrinkage resistance may decrease. If the amount exceeds 300 parts by mass, the rebound rate when sprayed may increase.

The polymer emulsion used in the present invention is:
An aqueous emulsion in which a polymer compound is dispersed and stabilized in water, and a commercially available emulsion can be used. The polymer emulsion entrains air during mixing to increase fluidity, enhance water retention after hardening of the quick-setting cement concrete, and coat the particle surface of the quick-setting cement concrete. Resistance to sexual development,
And the resistance to drying shrinkage can be improved. Therefore, the quick-setting cement concrete to which the polymer emulsion is added has excellent durability.

As the polymer compound in the polymer emulsion, styrene-butadiene-based copolymer, polychloroprene, polyurethane,
Acrylic ester copolymer, vinyl acetate copolymer,
And an ethylene-vinyl acetate copolymer.
Among them, the use of a styrene-butadiene-based copolymer is preferred because the miscibility with cements is improved and various physical properties of cement concrete and quick-setting cement concrete can be improved.

The concentration of the polymer emulsion is from 30 to 65
% Is preferable, and 40 to 55% is more preferable. If it is less than 30%, fluidity and durability may not be improved.
%, The stability of the emulsion itself is poor, and the fluidity and durability may not be improved.

The amount of the polymer emulsion to be used is preferably 1 to 20 parts by mass, more preferably 3 to 15 parts by mass in terms of solid content, based on 100 parts by mass of the hydraulic material. If the amount is less than 1 part by mass, the fluidity and durability may not be improved.
If the amount exceeds 0 parts by mass, the onset of setting is delayed, and the long-term strength development may be reduced.

Further, in the present invention, a fine powder may be used in order to improve the pumpability and the adhesion property at the time of spraying.

The particle size of the fines, from the viewpoint of improving the adhesion properties at the time of pumpability and spraying, preferably 3000 cm ² / g or more in Blaine value, 7000 cm ² / g or more is more preferable.

Examples of the fine powder include beidellite, bentonite, metakaolin, kaolinite, halloysite, montmorillonite, and layered aluminosilicates as main components.
Pyrophyllite, vermiculite, mica, chlorite,
Clay minerals such as saponite, sepiolite, and acid clay, fine slag, fine fly ash, silica fume, and limestone powder. Among these,
From the viewpoint of pumpability, fluidity, and adhesion characteristics at the time of spraying, one or two or more kinds selected from the group consisting of silica fume, limestone powder, and clay mineral are preferred, and silica fume is more preferred.

The amount of the fine powder to be used is preferably 0.5 to 5 parts by mass, more preferably 1 to 3 parts by mass, per 100 parts by mass of the hydraulic material. If the amount is less than 0.5 part by mass, the adhesive properties at the time of spraying may not be improved, and if it exceeds 5 parts by mass, the pumpability and the fluidity may decrease.

Further, in the present invention, a viscosity modifier for imparting viscosity to cement concrete and improving the adhesive property at the time of spraying may be used.

As the viscosity modifier used in the present invention, a high molecular compound having hydrophilicity can be mentioned. Examples of hydrophilic polymer compounds include celluloses such as carboxymethylcellulose, methylcellulose, hydroxypropylcellulose, methylethylcellulose, and ethylcellulose; amylose, agar, alginic acid, sodium alginate, pullulan, and polysaccharides such as guar gum; Various derivatives, polyvinyl alcohol, and
Examples include polyethylene oxide. Among these, it is excellent in adhesion characteristics and it is difficult to inhibit strength development,
Cellulose is preferred, and methylcellulose is more preferred.

The amount of the viscosity modifier used is based on 100 parts by mass of the hydraulic material and the fine powder used as required.
0.02 to 0.3 part by mass is preferable, and 0.08 to 0.2 part by mass.
Parts by mass are more preferred. If the amount is less than 0.02 parts by mass, it may be difficult to impart viscosity. If the amount exceeds 0.3 parts by mass, the fluidity may be excessively reduced and the pumpability may be impaired.

Further, in the present invention, fibers may be used to improve the bending properties of the quick-setting cement concrete hardened by spraying and to prevent mortar from falling due to peeling or the like. The fibers are mainly added to the cement concrete side in advance, but may be added to the quick setting agent side in advance.

Examples of the fibers include steel fibers, glass fibers, and polymer fibers. Among these, polymer fibers are preferable in that they have good dispersibility with hydraulic materials and improve bending properties. Vinylon fiber,
Examples include polypropylene fiber, polyethylene fiber, polyacrylonitrile fiber, and aramid fiber. Among these, vinylon fibers are preferred in view of bending toughness.

The fiber length of the fiber is preferably 2 to 15 mm,
-10 mm is more preferred. If it is less than 2 mm, the bending properties may not be improved, and if it exceeds 15 mm, the pumpability of the cement concrete may be impaired.

The amount of the fiber used is preferably from 0.05 to 1 part by mass, more preferably from 0.1 to 1 part by mass, based on 100 parts by mass of the hydraulic material, the aggregate, and the fine powder and the viscosity modifier used if necessary.
0.8 parts by mass is more preferred. If the amount is less than 0.05 part by mass, the bending properties may not be improved. If the amount exceeds 1 part by mass, the fluidity of the cement concrete may be reduced, and the pumpability may be impaired.

The quick-setting agent used in the present invention contains aluminum sulfate. Among the quick-setting agents, a liquid quick-setting agent is preferable because the components in the quick-setting agent can be uniformly dispersed and the handling is easy. Here, the liquid quick-setting agent containing aluminum sulfate includes an aqueous solution and a suspension.

Examples of the aluminum sulfate include generally commercially available powdery aluminum sulfate, and any of anhydrous salts and hydrated salts can be used.

The solid concentration in the liquid quick-setting admixture is 20 to 40.
% Is preferable and 25 to 35% is more preferable. If it is less than 20%, the initial setting and initial strength development may be impaired. If it exceeds 40%, the long-term strength development is impaired, the viscosity of the liquid quick-setting agent increases, and the pumpability decreases. The components in the liquid quick-setting admixture become difficult to uniformly disperse, which may make it difficult to handle the liquid quick-setting admixture.

The amount of the quick setting agent used is preferably from 0.2 to 10 parts by mass, more preferably from 0.5 to 8 parts by mass, based on 100 parts by mass of the hydraulic material. If the amount is less than 0.2 parts by mass, it is difficult to promote the initial setting, the strength developing property is reduced, the adhesion property at the time of spraying is reduced, and dripping and rebound may increase. This may cause solidified matter to adhere to the inside of the pipe, and may reduce the long-term strength development.

Further, in the present invention, a water reducing agent or a setting retarder may be used in combination.

The water powder ratio (W / P) of the cement concrete of the present invention is preferably 30 to 70%, more preferably 35 to 65%. If it is less than 30%, the viscosity of the cement concrete is large, and the spraying workability and pumpability may be reduced. If it exceeds 70%, the strength development and initial setting may be adversely affected. Here, the water in the polymer emulsion is considered as the water here, but the water in the liquid quick-setting agent is not considered. The powder refers to a hydraulic material, and a total of fine powder and a viscosity modifier used as needed.

Examples of the method for preparing the spray material of the present invention include the following methods. The quick-setting agent is pumped by a plunger pump or the like to the outside of a double pipe having several holes or grooves in the inner wall surface. Also, cement concrete is pumped inside the double pipe. The quick-setting agent mixed with air and formed into a mist is pressure-fed from the outside of the double pipe to the inside of the double pipe through the hole or groove of the double pipe to join and mix with the cement concrete, and quickly set. Sprayed as cement cement.

When the quick-setting agent is in a liquid state, examples of its preparation method include the following methods. First,
Pneumatic transportation using a quick-setting additive usually used for powder quick-setting agents, through the inside of a double tube having several holes or grooves on the inner wall, and from the outside of the double tube, Water and, optionally, air are transported through the holes or grooves to prepare a liquid quick setting agent. The prepared liquid quick-setting agent becomes a mist with air, is mixed and mixed with cement concrete, and is sprayed as quick-setting cement concrete.

[0043]

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

Experimental Example 1 Dry cement mortar was prepared by mixing 100 parts by weight of the hydraulic material shown in Table 1 and 200 parts by weight of aggregate. A wet cement mortar was prepared by mixing the dry cement mortar with 100 parts by weight of the hydraulic material and a polymer emulsion having a solid content concentration shown in Table 1 and a water powder ratio of 45%. In this wet cement mortar,
A liquid quick-setting agent composed of aluminum sulfate and having a solid content of 27% was added in an amount of 5 in terms of solid content with respect to 100 parts by mass of the hydraulic material.
A mass part was added and kneaded for 10 seconds to prepare a quick-setting cement mortar. The mortar flow of the obtained wet cement mortar containing no quick setting agent was measured, and the setting property of the obtained quick setting cement mortar was measured. Table 1 shows the results.

(Materials used) Hydraulic material a: ordinary Portland cement (specific gravity 3.1
6, commercially available product) 100 parts by mass, calcium sulfoaluminate (main component C ₄ A ₃ SO ₃ , Blaine specific surface area 350)
0 cm ² / g) Mixture consisting of 5 parts by mass Hydraulic material b: ordinary Portland cement, specific gravity 3.1
6. Commercial product Hydraulic material c: Early strength Portland cement (specific gravity 3.1
4, commercially available product) 100 parts by mass, calcium aluminates (main component C ₁₂ A ₇ , amorphous, Blaine specific surface area 5900)
cm ² / g) A mixture consisting of 2 parts by mass and 2 parts by mass of gypsum Aggregate: lime sand from Aomi-machi, Niigata, particle size of 1.5 mm or less, specific gravity 2.67 Polymer emulsion: styrene-butadiene copolymer Emulsion, solid content concentration 45%, commercial product Aluminum sulfate: dodecahydrate, commercial product

(Measurement Method) Mortar Flow: A wet cement mortar containing no quick-setting agent was measured in accordance with JISA5201. Setting property: Under the condition of 20 ° C, a liquid quick-setting agent is mixed,
28. With regard to the quick-setting cement mortar prepared by kneading for 10 seconds, the time from the quick filling into the mold until the penetration resistance of the proctor reaches 3.5 N / mm ² is the first time.
The time required to reach 0 N / mm ² was defined as the end.

[0047]

[Table 1]

Experimental Example 2 In a dry cement mortar, a polymer emulsion having a solid content concentration of 5 parts by mass with respect to 100 parts by mass of the hydraulic material a,
A wet cement mortar is prepared by mixing 100 parts by mass of the hydraulic material and the aggregate with fibers of the parts by mass shown in Table 2 and water having a water powder ratio of 45% to prepare a wet cement mortar. 27% liquid quick setting agent was added to hydraulic material 1
A quick setting cement mortar was prepared by adding 5 parts by mass in terms of solid content with respect to 00 parts by mass, and the mortar flow was calculated for the obtained wet cement mortar not containing the quick setting agent.
The procedure was carried out in the same manner as in Experimental Example 1 except that the flexural toughness coefficient of the obtained quick-setting cement mortar was measured. Table 2 shows the results.

(Materials used) Fiber A: Vinylon fiber, fiber length 6 mm, commercial product Fiber B: polypropylene fiber, fiber length 6 mm, commercial product

(Measurement method) Flexural toughness coefficient: For quick setting cement mortar, JS
It measured according to CE-G552. The measurement material age is 28 days.

[0051]

[Table 2]

Experimental Example 3 In dry cement mortar, a polymer emulsion having a solid content concentration of 5 parts by mass with respect to 100 parts by mass of the hydraulic material a, a viscosity modifier of parts by mass shown in Table 3, a hydraulic material,
The total amount of aggregate and viscosity modifier is 100 parts by mass.
An experiment was conducted except that 5 parts by mass of fiber A and water having a water powder ratio of 45% were mixed to prepare a wet cement mortar, and the mortar flow was measured for the obtained wet cement mortar containing no quick setting agent. It carried out like Example 1. Table 3 shows the results.

(Materials used) Viscosity modifier: methylcellulose, commercial product

[0054]

[Table 3]

Experimental Example 4 A polymer emulsion having a solid content of 5 parts by mass with respect to 100 parts by mass of the hydraulic material a was added to dry cement mortar.
Total of 10 parts by mass of fine powder, hydraulic material and fine powder shown in Table 4
0.1 parts by mass of a viscosity modifier with respect to 0 parts by mass, and
Hydraulic material, aggregate, viscosity modifier, and fine powder total 100
A wet cement mortar was prepared by mixing 0.5 parts by mass of fiber A and water having a water powder ratio of 45% with respect to parts by mass, and the mortar flow was calculated for the obtained wet cement mortar containing no quick setting agent. Except having measured, it carried out similarly to Experimental example 1. Table 4 shows the results.

(Materials used) Fine powder: silica fume, specific surface area 7000 cm ² / g or more, commercial product

[0057]

[Table 4]

Experimental Example 5 In a dry cement mortar, a polymer emulsion having a solid content of 5 parts by mass with respect to 100 parts by mass of the hydraulic material a,
0.1 parts by mass of a viscosity modifier and 100 parts by mass of a hydraulic material, an aggregate, a viscosity modifier and a fine powder with respect to 2 parts by mass of fine powder, hydraulic material and fine powder in total of 100 parts by mass. A wet cement mortar is prepared by mixing 0.5 parts by mass of fiber A and water having a water powder ratio of 45%, and a liquid quick-setting agent made of aluminum sulfate and having a solid content of 27% is used as a hydraulic material. An experimental example except that a quick-setting cement mortar was prepared by adding 100 parts by weight of a solid content in terms of solid content and a quick-setting cement mortar was prepared, and the setting property and prismatic compressive strength of the obtained quick-setting cement mortar were measured. Performed similarly to 1.
Table 5 shows the results.

(Measurement Method) Prismatic Compressive Strength: Quick-setting cement mortar prepared by cooling all the material temperatures to 5 ° C. in advance and quickly adding
Packing while shaking into the form of cm × 4cm × 16cm,
Cured at 20 ° C until the specified age. Curing is performed at a temperature of 20.
Curing in the air at 60 ° C and 60% humidity.
According to IS R5201.

[0060]

[Table 5]

Experimental Example 6 A polymer emulsion having a solid content concentration of 5 parts by mass relative to 100 parts by mass of the hydraulic material a was added to dry cement mortar,
0.1 parts by mass of a viscosity modifier and 100 parts by mass of a hydraulic material, an aggregate, a viscosity modifier and a fine powder with respect to 2 parts by mass of fine powder, hydraulic material and fine powder in total of 100 parts by mass. A wet cement mortar was prepared by mixing 0.5 parts by mass of fiber A and water having a water powder ratio of 45%, and a liquid quick-setting agent made of aluminum sulfate and having a solid concentration shown in Table 6 was added to water. 5 in terms of solid content with respect to 100 parts by mass of the hard material
A quick-setting cement mortar was prepared by adding parts by mass, and the same procedure as in Experimental Example 1 was carried out except that the setting property and the prismatic compression strength of the obtained quick-setting cement mortar were measured. Table 6 shows the results.

[0062]

[Table 6]

Experimental Example 7 100 parts by mass of hydraulic material a, 200 parts by mass of aggregate, fine powder 2
0.1 parts by weight of the viscosity modifier based on 100 parts by mass of the hydraulic material and the fine powder, and 100 parts by mass of the hydraulic material, aggregate, viscosity modifier and the fine powder. A dry cement mortar consisting of fiber A in parts by mass shown in No. 7 was prepared. This dry cement mortar is put into a pan-type mixer, and 5 parts by mass of a polymer emulsion in terms of solid content and water having a water powder ratio of 45% are mixed with 100 parts by mass of the hydraulic material a, and kneaded for 5 minutes. A wet cement mortar was prepared. Next, this wet cement mortar was dropped into a hopper, and was pressure-fed using a squeeze pump through a pipe 10 m having an inner diameter of 50 mm. The discharge capacity at this time was 1.9 m ³ / hr. The mortar pumpability of the obtained wet cement mortar containing no quick-setting agent was measured. Table 7 shows the results. Experimental Example 8
Thereafter, 5 parts by mass of a liquid quick setting agent composed of aluminum sulfate and having a solid content concentration of 27% in terms of solid content with respect to 100 parts by mass of the hydraulic material, is mixed and mixed with the wet cement mortar just before the nozzle to quickly set. A cement mortar was prepared and sprayed from a nozzle.

(Measurement method) Mortar pumping property: When wet cement mortar containing no quick-setting agent is pumped and the mortar is continuously discharged from the end of the hose, the discharge is possible, but discontinuous discharge is slightly observed. Was evaluated as "poor", and discontinuous discharge was increased, and pressure resistance was applied, and the hose pulsated.

[0065]

[Table 7]

Experimental Example 8 100 parts by mass of hydraulic material a, 200 parts by mass of aggregate, fine powder 2
Parts by mass, with respect to a total of 100 parts by mass of the hydraulic material and the fine powder, the viscosity modifier in parts by mass shown in Table 8, and a hydraulic material,
A dry cement mortar consisting of 0.5 parts by mass of fiber A is prepared with respect to 100 parts by mass of aggregate, viscosity modifier, and fine powder in total, and 5 parts by mass in terms of solid content with respect to 100 parts by mass of hydraulic material a. Polymer emulsion and water powder ratio 45%
Is mixed with water to prepare a wet cement mortar, and 5 parts by mass of a liquid quick setting agent composed of aluminum sulfate and having a solids concentration of 27% is added to 100 parts by mass of the hydraulic material in terms of solids, and quick setting is performed. A cement mortar was prepared, and the same procedure as in Experimental Example 7 was carried out, except that the mortar pumpability and the adhesive property of the obtained quick-setting cement mortar were measured for the obtained quick-setting cement-free wet cement mortar. . Table 8 shows the results.

(Measurement method) Adhesion characteristics: 4 m height x 4 m width x 5 length with nozzle fixed
m of quick setting cement mortar on the side wall of a mock tunnel
Spraying was performed for 5 seconds, and the distance from the side wall serving as the spraying surface to the top of the quick-setting cement mortar adhering thereto was measured, and the result was taken as the adhesion property.

[0068]

[Table 8]

EXPERIMENTAL EXAMPLE 9 100 parts by mass of hydraulic material a, 200 parts by mass of aggregate, 0.1 parts by mass of fineness powder shown in Table 9, 0.1 part by mass of viscosity modifier with respect to 100 parts by mass of total of hydraulic material and fine powder , And a hydraulic material, an aggregate, a viscosity modifier, and a dry cement mortar composed of 0.5 parts by mass of fiber A based on 100 parts by mass of the fine powder, and 100 parts by mass of hydraulic material a A wet cement mortar is prepared by mixing 5 parts by mass of a polymer emulsion in terms of solid content and water having a water powder ratio of 45%, and a liquid quick-setting agent made of aluminum sulfate and having a solid content of 27% is used as a hydraulic material. A quick setting cement mortar was prepared by adding 5 parts by mass in terms of solid content to 100 parts by mass, and the resulting quick setting cement-free wet cement mortar was evaluated for mortar pumpability and obtained quick setting cement mortar. The procedure was performed in the same manner as in Experimental Example 7 except that the adhesion characteristics of rutile were measured. Table 9 shows the results.

[0070]

[Table 9]

Experimental Example 10 100 parts by mass of hydraulic material a, 200 parts by mass of aggregate, fine powder 2
Parts by mass, 0.1 part by mass of the viscosity modifier with respect to 100 parts by mass of the hydraulic material and the fine powder, and 0 parts by mass with respect to 100 parts by mass of the hydraulic material, the aggregate, the viscosity modifier and the fine powder. A dry cement mortar comprising 0.5 parts by mass of fiber A is prepared, and 5 parts by mass of a polymer emulsion in terms of solid content and water having a water powder ratio of 45% are mixed with 100 parts by mass of the hydraulic material a and wetted. A cement mortar was prepared, and a liquid quick-setting agent composed of aluminum sulfate and having a solid content of 27% was converted into a solid content based on 100 parts by mass of the hydraulic material.
Prepare the quick setting cement mortar by adding the parts by mass shown in
The same procedure as in Experimental Example 7 was carried out, except that the obtained quick-setting cement mortar was measured for sag, rebound rate, adhesive strength, and nozzle clogging state. Table 10 shows the results.

(Measurement Method) Dropping: Quick setting cement mortar was sprayed at a pumping speed of 2 m ³ / h for 2 minutes onto a simulated tunnel 3.5 mm high and 2.5 m wide made of an iron plate in an arch shape. Later conditions were observed. When no dripping occurred, it was evaluated as ○, when slight dripping occurred, as Δ, and when much dripping occurred, as X. 2. Rebound rate: Height at which quick-setting cement mortar is made of an iron plate in an arch shape at a pumping speed of 2 m ³ / h for 2 minutes.
It was sprayed on a simulated tunnel of 5m x 2.5m in width. afterwards,
(Rebound rate) = (mass of quick-setting cement mortar dropped without adhering to the simulated tunnel) / (mass of quick-setting cement mortar sprayed on the simulated tunnel) × 100
(%). Adhesion strength: Adhesion properties were also indicated by adhesion strength. Height 30cm
A quick-setting cement mortar was sprayed on a concrete plate having a surface of 30 cm wide by 6 cm thick and chipped to a thickness of 4 to 6 cm, and the surface was immediately capped. Thereafter, the mixture was cured in the air for 28 days under the conditions of a temperature of 20 ° C. and a humidity of 60%, cut in a grid pattern from the surface to a size of 4 cm × 4 cm with a concrete cutter, and the adhesion strength was measured by the Kenken formula. Nozzle clogging condition: After rapidly setting cement mortar was sprayed from the nozzle for 4 minutes, the inside of the nozzle was observed, and when 30% or more of the internal cross-section was closed, x: 10 to 30 of the internal cross-section
% Was closed, and less than 10% of the internal cross section was closed.

[Table 10]

Experimental Example 11 100 parts by mass of hydraulic material a, 200 parts by mass of aggregate, fine powder 2
Parts by mass, 0.1 part by mass of the viscosity modifier with respect to 100 parts by mass of the hydraulic material and the fine powder, and 0 parts by mass with respect to 100 parts by mass of the hydraulic material, the aggregate, the viscosity modifier and the fine powder. A dry cement mortar comprising 0.5 parts by mass of fiber A is prepared, and 5 parts by mass of a polymer emulsion in terms of solid content and water having a water powder ratio of 45% are mixed with 100 parts by mass of the hydraulic material a and wetted. A cement mortar was prepared, and a quick setting cement mortar made of aluminum sulfate was added by adding 5 parts by mass of a liquid quick setting agent having a solid content concentration shown in Table 11 in terms of solid content to 100 parts by mass of the hydraulic material. The same procedure as in Experimental Example 7 was carried out, except that the quick-setting mortar pumpability of the obtained quick-setting cement mortar was measured. Table 11 shows the results.

(Measurement method) Quick setting mortar miscibility: quick setting cement mortar is 2 m
^It was sprayed at a pumping speed of ³ / h for 2 minutes into a simulated tunnel 3.5 mm high x 2.5 m wide made of an iron plate in an arch shape.
Touch the sprayed surface of the quick setting cement mortar, and mark the case where there is a hardened part and the part that is not hardened. When it was, it was marked as ○.

[0075]

[Table 11]

Experimental Example 12 100 parts by mass of hydraulic material a, 200 parts by mass of aggregate, fine powder 2
Parts by mass, 0.1 part by mass of the viscosity modifier with respect to 100 parts by mass of the hydraulic material and the fine powder, and 0 parts by mass with respect to 100 parts by mass of the hydraulic material, the aggregate, the viscosity modifier and the fine powder. A dry cement mortar composed of 0.5 parts by mass of fiber A was prepared, and 100 parts by mass of the hydraulic material a was mixed with 45 parts by mass of a polymer emulsion and 45% by mass of a polymer emulsion as shown in Table 12 in terms of solid content. A wet cement mortar is prepared by adding 5 parts by mass of a liquid quick setting agent consisting of aluminum sulfate and having a solid content of 27% in terms of solid content to 100 parts by mass of the hydraulic material to prepare a quick setting cement mortar. And
The same procedure as in Experimental Example 7 was carried out, except that the number of cycles, the neutralization depth, the change in length, and the column compressive strength of the obtained quick-setting cement mortar were measured. Table 12 shows the results.

(Measurement Method) Number of Cycles: The freeze-thaw resistance was evaluated by the number of cycles. The obtained quick-setting cement mortar is 50 cm long.
After spraying on a box form measuring 50 cm wide by 20 cm thick, a prism having a length of 40 cm, a width of 10 cm and a thickness of 10 cm was cut and taken out to obtain a specimen. Using this specimen, a freeze-thaw test was performed according to JSCE-G501. The relative dynamic elastic modulus was evaluated every 15 cycles, and the number of cycles at which the relative dynamic elastic modulus showed 60% or less was measured. Neutralization depth: The resistance to neutralization was evaluated by the neutralization depth. The obtained quick-setting cement mortar is vertically 50
After spraying on a box form having a size of 50 cm x 50 cm x 20 cm in thickness, a cylinder having a diameter of 5 cm and a height of 10 cm was cut out and taken out to obtain a specimen. An accelerated neutralization test was performed using this specimen. The specimen was air-cured for 28 days at a temperature of 20 ° C. and a humidity of 60%, and the upper and lower surfaces of the specimen were sealed with an epoxy resin, and the specimen was cured at a temperature of 30 ° C., a humidity of 60% and a carbon dioxide concentration of 5%. It was stored in an accelerated neutralization device under the conditions, and the neutralization depth at a given age was measured. Length change: Dry shrinkage resistance was evaluated by length change. The resulting quick-setting cement mortar is 4 cm long x 4 cm wide.
A test piece was sprayed on a triple mold having a size of 16 cm and a thickness of 16 cm, and then removed from the mold. Using this specimen, a length change test was performed. The test specimen was air-cured under the conditions of a temperature of 20 ° C. and a humidity of 60%, and the length change at a predetermined age was measured according to JIS A 1129, a dial gauge method. Cylindrical compressive strength: The obtained quick setting cement mortar
After spraying on a box form of 0 cm × 50 cm × 20 cm in thickness, a cylinder having a diameter of 5 cm × a height of 10 cm was cut out and taken out to obtain a specimen. Using this specimen, a compression strength test was measured according to JIS A 1108.

[0078]

[Table 12]

Experimental Example 13 100 parts by mass of hydraulic material a, 2 parts by mass of aggregates, 2 parts by mass of fine particles shown in Table 13, 0.1 part by mass of viscosity modifier based on 100 parts by mass of hydraulic material and fine particles in total , And a hydraulic material, an aggregate, a viscosity modifier, and a dry cement mortar composed of 0.5 parts by mass of fiber A based on 100 parts by mass of the fine powder, and 100 parts by mass of hydraulic material a A wet cement mortar is prepared by mixing 5 parts by mass of a polymer emulsion in terms of solid content and water having a water powder ratio of 45%, and a liquid quick-setting agent made of aluminum sulfate and having a solid content of 27% is used as a hydraulic material. Experimental Example 7 was repeated except that 5 parts by mass in terms of solid content was added to 100 parts by mass to prepare a quick-setting cement mortar, and the length change and the rebound rate of the obtained quick-setting cement mortar were measured. Similarly row Was. Table 13 shows the results.

[0080]

[Table 13]

[0081]

By using the spray material of the present invention,
A spray structure having excellent durability can be obtained. In particular, when a liquid quick-setting agent is used, dust, mist, and rebound are reduced, and the long-term strength can be improved. In addition, when the deteriorated surface is scraped off and the concrete structure is repaired by spraying with the cement mortar of the present invention, the repaired portion has a height of 10 cm.
The above thick blowing can be performed. Therefore, it can also be used for repair when cement concrete is deeply removed to the back side of the reinforcing bar.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) E21D 11/10 E21D 11/10 D // (C04B 28/04 (C04B 28/04 24:26 24:26 G 22:14 22:14 Z 20:00 20:00 B 24:38 24:38 D 16:06) 16:06) A 103: 12 103: 12 111: 70 111: 70 111: 72 111: 72 F Terms (reference) 2D044 DC04 2D055 BA06 CA01 KA05 KB07 KB10 LA04 LA06 LA10 4G012 MB13 PA10 PA24 PB04 PB10 PB11 PB12 PB28 PB40 PC06 PC08 PE01 4G056 AA07 AA18 CB32 CC01 CD36

Claims (7)

[Claims] 1. 100 parts by mass of hydraulic material, aggregate 150 to
A spray material comprising cement concrete containing 300 parts by mass, a polymer emulsion, and water, and a quick-setting admixture containing aluminum sulfate. 2. The spray material according to claim 1, further comprising fine powder. 3. The spray material according to claim 1, further comprising a viscosity modifier. 4. The method according to claim 1, further comprising a fiber.
4. The spray material according to one of the three items. 5. A fine powder having a Blaine value of 3000 cm.
The spray material according to claim 2, which is not less than ² / g. 6. The quick-setting agent according to claim 1, wherein the quick-setting agent is a liquid quick-setting agent.
The spray material according to any one of the preceding claims. 7. 100 parts by mass of hydraulic material, aggregate 150 to
A cement concrete containing 300 parts by mass, a polymer emulsion and water is pumped, and a quick-setting agent containing aluminum sulfate is mixed and mixed during the pumping to prepare a quick-setting cement concrete and sprayed. A spraying method characterized by the following.