JPH10167790A - Spraying material and spraying construction method by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a spraying material aiming at the improvement of a slump retaining property, an initial and a long term strength developing property, a dust reducing property, a rebounding property and working efficiency by including a cement and a powdery polycarboxylic acid-based high performance water reducing agent. SOLUTION: This spaying material is obtained by blending 100 pts.wt. cement, 0.01-5.0 pts.wt. powdery polycarboxylic acid-based high performance water educing agent having 0.1-200μm means particle diameter and obtained by reacting a copolymer obtained by mixing a polyalklylene glycol alkenyl ether of the formula [A is a 2-4C alkylene; R is H or a 1-4C alkyl; (a) is 0, 1; (n) is 1-60] with maleic anhydride so as to become 1/2 to 2/1 molar ratio and copolymerizing, with a calcium salt compound, drying and crushing, 1-20 pts.wt. coagulation accelerator such as sodium aluminate, etc., 1-20 pts.wt. rapid coagulating agent, 0.1-10 pts.wt. coagulation retarder, 0.001-1.0 pts.wt. dust reducing agent, 1-100 pts.wt. superfine powder having <=10μm means particle diameter and 0.5-7 pts.wt. fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spraying material containing a specific powdery polycarboxylic acid-based high-performance water reducing agent and spraying it on the ground surface exposed in tunnels such as roads, railways and headraces. The present invention relates to a spraying method using the method. In the present invention, dry cement mortar, cement mortar,
Paste and concrete are collectively called cement mortar or concrete.

[0002]

2. Description of the Related Art Conventionally, a method of spraying quick-setting concrete in which a quick-setting agent is mixed with concrete has been carried out in order to prevent collapse of an exposed ground such as tunnel excavation (Japanese Patent Publication No. Sho 5).
No. 2-4149). In this method, spray concrete is usually produced at a cement, aggregate, and water metering and mixing plant installed at the excavation site, transported by an agitator truck, pumped by a concrete pump, and installed at the junction pipe. This is a method of mixing with a quick-setting agent pumped from the other side and spraying it as a quick-setting sprayable concrete on the ground surface to a predetermined thickness. In this method, a high-performance water reducing agent having water reducing property, air entrainment property, and dispersibility may be added at the time of preparing the shotcrete in order to impart fluidity to the shotcrete. Examples of the high-performance water reducing agent include naphthalene sulfonate, melamine sulfonate, and polycarboxylic acid. The naphthalenesulfonate-based or melaminesulfonate-based high-performance water reducing agent can be used as a spray material by mixing it as a powder with various cement admixtures. However, the naphthalene sulfonate-based high-performance water reducing agent has a drawback that when used in combination with a cellulose-based dust reducing agent or an anti-rebound agent, the water reducing property, air entrainment, and dispersibility are lost. Both naphthalenesulfonate and melaminesulfonate high-performance water reducing agents also have the disadvantage that the effect of improving strength is small. further,
When the prepared shotcrete is kneaded, the slump changes greatly with time, and when it becomes necessary to knead the shotcrete due to mechanical / electrical trouble of the spraying device, the concrete becomes hard, and This has the disadvantage of adversely affecting the properties of the concrete, making it difficult to mix uniformly with the quick-setting agent, resulting in non-uniform quality quick-setting sprayed concrete, and the risk of concrete falling off the tunnel surface. Was.

[0003] Therefore, a polycarboxylic acid-based high-performance water reducing agent having a small slump loss has been used. As polycarboxylic acid type high performance water reducing agents, polyalkylene glycol monoallyl ether-maleic acid type copolymer, polyalkylene glycol mono (meth) acrylate- (meth) acrylic acid type copolymer, water-soluble olefin The use of copolymers with α, β-unsaturated dicarboxylic acid derivatives, saponified sulphonated styrene-maleic acid copolymers, saponified styrene-maleic acid copolymers, etc. A method for improving fluidity and quick setting has been proposed (Japanese Patent Publication No. 5-53743).
JP-A-3-153550).

[0004]

However, these polycarboxylic acid-based high-performance water reducing agents have not been satisfactory in terms of water reduction, slump loss, and strength. The water reducing agent is preferably a powder that can be premixed with various powder materials in advance so that it is not necessary to add the water reducing agent at the spraying site, but a conventional polyalkylene glycol (meth) acrylate- (meth) acrylic acid-based The polymer is
There is a problem that it is usually waxy or syrupy at room temperature and cannot be used unless it is an aqueous solution. Therefore, in the spraying operation, cement, powder cement admixtures such as quick setting agent,
In addition, a powdery cement admixture such as fly ash and the like and the water reducing agent must be separately measured and added separately on site, and there is a problem that workability is significantly reduced. Thus, a spraying material that is satisfactory in terms of dispersibility, quick setting, strength, and workability has been required.

As a result of various studies on these problems, the present inventor has found that various cements such as Portland cement, alumina cement and mixed cement, various cement admixtures such as silica fume, blast furnace slag and fly ash,
And other powdery high-performance water reducing agents, powdery dust reducing agents,
By using a specific powdery polycarboxylic acid-based high-performance water reducing agent that can be premixed with various powder materials such as various powder cement admixtures such as powder antifoaming agents, setting accelerators, setting retarders, etc. The present invention was completed by obtaining the knowledge that a high-quality sprayed material having excellent slump holding properties, quick setting properties, initial and long-term strength development properties, dust reduction properties, rebound properties, and workability can be obtained. .

[0006]

That is, the present invention provides a powdery polycarboxylic acid-based high-performance polymer comprising a cement and a calcium salt of a copolymer of polyalkylene glycol monoalkenyl ether and maleic acid represented by the chemical formula (1). A spray material characterized by containing a water reducing agent.

Embedded image And a cement, a powdery polycarboxylic acid-based high-performance water reducing agent comprising a calcium salt of a copolymer of a polyalkylene glycol monoalkenyl ether represented by the chemical formula (1) and maleic acid, and a rapid mixture comprising calcium aluminate. The spray material according to claim 1 or 2, wherein the spray material comprises a binder.
0 is the spraying material characterized by being 0,
The spraying material characterized in that the setting agent contains a setting accelerator, and further, one or more selected from the group consisting of a setting retarder, a dust reducing agent, an ultrafine powder, and a fiber The spraying material is characterized by containing an admixture of the above, and a spraying method characterized by using the spraying material.

[0007]

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

As the cement used in the present invention, there are various kinds of portland cements which are usually commercially available, such as ordinary, fast, moderate heat, and super fast, and various kinds of portland cement mixed with fly ash, blast furnace slag, etc. A mixed cement, a commercially available fine particle cement and the like can be mentioned, and various Portland cements and various mixed cements may be used after pulverized.

The powdery polycarboxylic acid-based high-performance water reducing agent used in the present invention is a calcium salt of a copolymer of a polyalkylene glycol alkenyl ether and maleic acid represented by the following chemical formula (1) (hereinafter referred to as the present copolymer). Coalesced calcium salt).

Embedded image

In the chemical formula (1), among A, an ethylene group having 2 carbon atoms is preferable in that the calcium salt of the copolymer has high water solubility. The alkyl group represented by R is preferably a methyl group because the copolymer can be easily produced and has high water solubility. n is preferably 1 to 60 from the viewpoint of dispersibility. 1
If it is less than 60, no dispersibility can be obtained, and if it exceeds 60, the viscosity of the reaction solution increases during the production of the copolymer, and the reactivity may decrease.

The weight average molecular weight of the copolymer calcium salt is preferably from 3,000 to 100,000. If it is less than 3,000, the dispersibility decreases, and if it exceeds 100,000, no further effect can be expected, and the cost may increase. The weight-average molecular weight used was, for example, a value determined by aqueous GPC using a known polyethylene glycol as a standard substance.

The copolymer of polyalkylene glycol monoalkenyl ether represented by the formula (1) and maleic acid (hereinafter referred to as the present copolymer) can be produced by a known production method. For example, Japanese Patent Application Laid-Open No.
According to the method described in -46652, a copolymer of polyalkylene glycol monoallyl ether and maleic anhydride or a copolymer of polyalkylene glycol monovinyl ether and maleic anhydride, in an organic solvent or in the absence of a solvent, It can be produced by radical polymerization using a radical initiator. Among the polyalkylene glycol monoalkenyl ethers used in the present copolymer, the copolymerizability with maleic anhydride, productivity, and excellent water reduction, high polymerization rate, and, in the obtained copolymer Polyalkylene glycol monovinyl ether in which a = 0 in chemical formula (1) is preferable because unreacted impurities can be easily removed. Incidentally, the copolymerization molar ratio of the polyalkylene glycol alkenyl ether and maleic anhydride is preferably 1/2 to 2/1 from the viewpoint that the copolymer can be easily obtained, and 1/2 is preferred.
1.2 to 1.2 / 1 is more preferable. Further, citraconic anhydride or maleimides may be used instead of maleic anhydride, but maleic anhydride is preferred in view of dispersibility and cost.

The calcium salt of the copolymer can be obtained by reacting the copolymer with a calcium salt compound.
As a production method, calcium hydroxide or a slurry of a mixture of calcium hydroxide and water is added to an organic solvent solution of the copolymer or a solution obtained by heating and melting the copolymer, followed by neutralization reaction, followed by drying and pulverization. And a method in which an organic solvent of the copolymer is stripped by heating steam to recover an aqueous solution of the copolymer, which is then reacted with calcium hydroxide, and then dried and pulverized.

The average particle size of the powdery polycarboxylic acid-based high-performance water reducing agent comprising the calcium salt of the copolymer is not particularly limited, but is preferably 0.1 to 200 μm. If it is less than 0.1 μm, the cost of forming fine particles increases, and if it exceeds 200 μm, the powdery polycarboxylic acid-based high-performance water reducing agent does not dissolve quickly or segregates when dry blended with various powder materials. May not be effective. Examples of the method of pulverizing the powdery polycarboxylic acid-based high-performance water reducing agent include powder spray drying, pulverization, and solvent precipitation.

The amount of the powdery polycarboxylic acid-based high-performance water reducing agent composed of the calcium salt of the present copolymer represented by the chemical formula (1) is preferably 0.01 to 5.0 parts by weight based on 100 parts by weight of cement. 0.02 to 5.0 parts by weight are more preferred.
If it is less than 0.01 part by weight, sufficient dispersion performance cannot be obtained,
If the amount exceeds 5.0 parts by weight, there is a possibility that setting delay or material separation may occur.

The calcium salt of the copolymer represented by the chemical formula (1) is a powdery polycarboxylic acid-based high-performance water reducing agent. Therefore, various cements, various cement admixtures, and pre-mixed with various powdery cement admixtures in advance. Can be used as a mix product. For example, the effect of reducing dust and preventing rebound can be imparted by mixing in advance with a quick setting agent composed of a setting accelerator such as calcium aluminate, alkali metal aluminate or alkali metal carbonate.

In the present invention, cement mortar or
In terms of causing concrete to set, it is used as a quick setting agent.
It is preferred to use lucium aluminate. Cal
Cium aluminate is an early setting of concrete
A quick-setting component that causes the mineral, and its mineral component is C
aO is C, Al_Two O_Three Is A, C_Three A, C₁₂A
₇ , CA, and CA_Two Calcium aluminum, etc.
Heat-treated products are pulverized. Furthermore,
SiO 2 as another mineral component of_Two Aluminoke containing
Calcium ioate, C₁₂A₇ One of CaO to CaF_Two etc
C substituted with a halide of₁₁A₇・ CaX_Two (X is
Halogen such as fluorine), SO_ThreeC containing component_Four A_Three・ S
O_Three, Alumina cement, and sodium and potassium
And alkali metals such as lithium
Examples include crystalline alumina and amorphous alumina.
All can be used. Among them, in terms of reaction activity,
C₁₂A₇ Amorphous quenched quenched heat-treated material corresponding to composition
Platinum aluminate is preferred. Calcium aluminate
The grain size of the bran is
3000cm in value^Two/ g or more is preferable and 4000 cm^Two/ g or less
The above is more preferred. 3000cm^TwoIf it is less than / g, quick setting or first time
There is a possibility that the initial strength developability may decrease.

The amount of calcium aluminate used is preferably 1 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of cement. If it is less than 1 part by weight, initial setting does not occur, and if it exceeds 20 parts by weight, the long-term strength development may be impaired.

In the present invention, the setting of cement is promoted,
It is preferable to use a setting accelerator in terms of giving a quick setting force to the cement mortar.

Examples of the setting accelerator include alkali metal aluminates such as sodium aluminate, potassium aluminate and lithium aluminate, alkali metal carbonates such as sodium carbonate, potassium carbonate and lithium carbonate, sodium hydroxide, water and the like. Potassium oxide and alkali metal hydroxides such as lithium hydroxide, sodium sulfate, potassium sulfate, aluminum sulfate, and sulfates such as alum, slaked lime,
In addition, there may be mentioned amine compounds and the like, and one or more of these may be used in combination. Of these, the use of alkali metal aluminates or alkali metal carbonates is preferred from the viewpoint of coagulation. In the present invention, it is preferable to use calcium aluminate and a setting accelerator in combination from the viewpoint of improving the initial setting property and the strength developing property. In some cases, the setting accelerator may be dissolved in water and used as a liquid.

When calcium aluminate is not used in combination, the amount of the setting accelerator used is preferably 1 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of cement. If the amount is less than 1 part by weight, the setting of the cement mortar is not promoted, and if it exceeds 20 parts by weight, the long-term strength development may be adversely affected.

When calcium aluminate is used in combination, the amount of the setting accelerator used is preferably 0.5 to 50 parts by weight, more preferably 1 to 30 parts by weight, based on 100 parts by weight of calcium aluminate. preferable. If the amount is less than 0.5 part by weight, the setting of the cement mortar is not promoted, and if it exceeds 50 parts by weight, the long-term strength development may be adversely affected.

When calcium aluminate and the setting accelerator are mixed, the amount of the quick setting agent to be used is preferably 1 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of cement. If the amount is less than 1 part by weight, the setting of the cement mortar is not promoted, and if it exceeds 20 parts by weight, there is a possibility that the long-term strength development may be inhibited.

In the present invention, it is preferable to use one or more admixtures selected from the group consisting of a setting retarder, an ultrafine powder, a dust reducing agent and fibers.

The setting retarder refers to a substance that delays the setting time of cement mortar, and examples thereof include organic acids, alkali metal carbonates, alcohols, phosphates and borates.

Examples of the organic acid include gluconic acid, tartaric acid, citric acid, malic acid, lactic acid and salts thereof. The amount of the organic acid used is preferably 0.05 to 3 parts by weight, more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of cement. Less than 0.05 parts by weight has no effect.
If the amount exceeds 3 parts by weight, curing may be excessively delayed, resulting in poor curing.

Examples of the alkali metal carbonate include sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium hydrogen carbonate. The amount of the alkali metal carbonate used is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of cement. 0.
If the amount is less than 1 part by weight, the effect is not obtained. If the amount is more than 10 parts by weight, the curing is excessively delayed, which may result in poor curing.

Examples of the alcohols include low molecular weight water-soluble alcohols having at least one hydroxyl group such as ethanol, methanol, ethylene glycol and glycerin, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, and amino acids such as triethanolamine. Water-soluble polymer polyols, which are adducts obtained by addition polymerization of propylene oxide and ethylene oxide to alcohols, and the like can be given. The amount of alcohol used is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of cement. If the amount is less than 0.1 part by weight, there is no effect. If the amount is more than 5 parts by weight, curing is excessively delayed, which may result in poor curing.

As the phosphate, monosodium phosphate,
Examples include disodium phosphate, trisodium phosphate, sodium hexametaphosphate, sodium tripolyphosphate, and sodium trimetaphosphate. Further, potassium may be used instead of sodium. Among these, sodium tripolyphosphate is preferable because it does not easily inhibit long-term strength development. The amount of the phosphate used is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 2 parts by weight, based on 100 parts by weight of the cement. If the amount is less than 0.1 part by weight, there is no effect. If the amount is more than 5 parts by weight, curing is excessively delayed, which may result in poor curing.

Examples of the borate include sodium borate and potassium borate. The amount of borate used is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of cement. If the amount is less than 0.1 part by weight, the effect is not obtained. If the amount is more than 10 parts by weight, curing is excessively delayed, which may result in poor curing.

Among these setting retarders, the combined use of an organic acid and an alkali carbonate is preferred from the viewpoint of the development of the initial strength.

When an organic acid and an alkali carbonate are used in combination,
The use amount of the alkali carbonate is preferably from 10 to 1,000 parts by weight, more preferably from 50 to 700 parts by weight, based on 100 parts by weight of the organic acid. Less than 10 parts by weight has no effect,
If the amount exceeds 1,000 parts by weight, the retardability may be reduced. The amount of the mixture of the organic acid and the alkali carbonate is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the cement. If the amount is less than 0.1 part by weight, the effect is not obtained. If the amount is more than 10 parts by weight, curing is excessively delayed, which may result in poor curing.

The dust reducing agent used in the present invention has a dust reducing property and an anti-rebound property, and includes methyl cellulose, hydroxypropyl cellulose, ethyl cellulose, methyl ethyl cellulose, polyvinyl alcohol, polyacrylic acid, polyvinyl acetate, and Examples include a polyethylene-polyvinyl acetate copolymer. Among them, methylcellulose is preferable because of its great effect. The use amount of the dust reducing agent is preferably 0.001 to 1.0 part by weight, and
-0.5 parts by weight is more preferred. If the amount is less than 0.001 part by weight, there is no effect. If the amount exceeds 1.0 part by weight, the viscosity increases, and there is a possibility that the pumping property may be impaired.

The ultrafine powder used in the present invention has an average particle size of 10
μm or less, reducing the amount of cement and dust,
It is possible to improve the pumpability of concrete. As ultra fine powder, fine slag, fly ash, bentonite,
Kaolin, silica fume, and the like. Among them, silica fume is preferred because of its great effect. The amount of the ultrafine powder to be used is preferably 1 to 100 parts by weight, more preferably 2 to 30 parts by weight, based on 100 parts by weight of cement. If the amount is less than 1 part by weight, there is no effect, and if it exceeds 100 parts by weight, the setting and the curing may be delayed.

The fibers used in the present invention can be either inorganic or organic and improve the impact resistance and elasticity of the shotcrete. The length of the fibrous substance is preferably 50 mm or less, and more preferably 30 mm or less, from the viewpoint of pumpability and mixing properties. If it exceeds 50 mm, the sprayed concrete may be blocked during the pumping. Examples of the inorganic fiber include glass fiber, carbon fiber, rock wool, asbestos, ceramic fiber, and metal fiber, and examples of the organic fiber include vinylon fiber, polyethylene fiber, polypropylene fiber, polyacryl fiber, and cellulose fiber. Polyvinyl alcohol fiber, polyamide fiber, pulp,
Hemp, wood wool, wood chips and the like. Among these,
Vinylon fibers and metal fibers are preferred in terms of economy. The amount of fiber used is 0.5 to 100 parts by weight of cement.
7 parts by weight is preferable, and 1 to 5 parts by weight is more preferable.
If it is less than 0.5 part by weight, there is no effect, and if it exceeds 7 parts by weight, the fluidity of the shotcrete may be reduced.

The amount of water used in the present invention is 100
35 to 60 parts by weight or less, preferably 4 parts by weight,
0 to 55 parts by weight is more preferred. If the amount is less than 35 parts by weight, kneading cannot be performed with a mixer, and if it exceeds 60 parts by weight, the strength development may be deteriorated.

The aggregate such as coarse aggregate and fine aggregate used in the present invention preferably has a low water absorption and a high aggregate strength, but is not particularly limited. The coarse aggregate preferably has a maximum diameter of 20 mm or less, and more preferably has a maximum diameter of 5 to 15 mm in consideration of pumpability. Fine aggregates having a maximum diameter of 5 mm or less are preferable.
Mountain sand, lime sand, silica sand, and the like.

When the spray material of the present invention is used, an antifoaming agent may be used to adjust the amount of entrained air. Examples of the antifoaming agent include lower alcohols, higher alcohols, fats and oils, fatty acids, fatty acid esters, phosphate esters, metal soaps, mineral oils, silicones, and polymers of polyethers. Can be Among these, polymers are preferable because of their large effects. Examples of the polymer include polyoxyalkylenes such as polyoxyethylene polypropylene adducts, polyoxyalkylene alkyl ethers in which a part of the terminal groups of polyoxyalkylenes are etherified with an alkyl group, and the terminal groups of polyoxyalkylenes. Polyoxyalkylene (alkyl) aryl ethers, some of which are etherified with aryl groups or alkylaryl groups, polyoxyalkylene fatty acid esters, in which some of the terminal groups of the polyoxyalkylenes are fatty acid-esterified,
Such as polyoxyalkylene (alkyl) aryl ether sulfates in which some of the terminal groups of the polyoxyalkylenes are sulfated, and polyoxyalkylene alkylamines in which some of the terminal groups of the polyoxyalkylenes are aminated. And polyoxyalkylenes. As the method of using the antifoaming agent, a method of adding the antifoaming agent in advance during the production of the present copolymer calcium salt, a method of impregnating the antifoaming agent with an inorganic powder such as white carbon or silica to obtain a powdery antifoaming agent And a method of premixing with the copolymer calcium salt and various powder materials.

The amount of the defoamer used is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the powdery polycarboxylic acid-based high-performance water reducing agent composed of the calcium salt of the present copolymer.
The amount is more preferably from 0.5 to 5 parts by weight. If it is less than 0.01 part by weight, there is no defoaming effect, and if it exceeds 10 parts by weight, no improvement in the defoaming effect can be expected, and the amount of entrained air may be rather increased.

In the spraying method of the present invention, the required physical properties,
From the economic point of view, workability, etc., it is possible to spray as dry cement mortar containing cement, cement mortar containing cement and water, paste, and concrete.If necessary, calcium aluminate may be added to these. The quick-setting agent contained may be mixed and mixed during the flow.

Examples of the spraying method include a dry spraying method and a wet spraying method. As a dry spraying method, while preparing a dry cement mortar that mixes cement and aggregate,
If necessary, a quick-setting agent is also carried in and mixed by a belt conveyor, pneumatically fed, and a quick-setting agent and water are sequentially supplied and sprayed on the way. As a wet spray method, a cement mortar prepared by mixing cement, aggregate, and water is prepared and pneumatically fed, for example, if necessary, a pneumatically setting agent is pneumatically fed from one of Y pipes provided on the way, A method of mixing and mixing with a cement mortar and spraying the mixture is exemplified. In the case of these spraying methods, admixtures other than quick-setting agents such as powdery polycarboxylic acid-based high-performance water reducing agents composed of the copolymer calcium salt, a setting accelerator, a setting retarder, a dust reducing agent, an ultrafine powder, and fibers. The agent or admixture can be mixed on either the mortar side or the quick setting agent side, and may be fed to only one side or may be used on both sides. There is no problem if the spray material according to the present invention is finally sprayed. The setting accelerator, the dust reducing agent, the ultrafine powder, and the fiber are preferably used on the mortar side in that excellent effects can be obtained. In some cases, a quick-setting agent and water may be mixed and used as a quick-setting agent slurry.

In the spraying method of the present invention, a conventional spraying equipment can be used. Normally, spray pressure is 2-5kg / c
m ² , spraying speed is 4-20 m ³ / h. The spraying equipment is not particularly limited as long as the spraying is sufficiently performed. For example, Aliver Co., Ltd. product name “Aliver 280” or the like is used for concrete pumping, and a quick-setting agent pumping device “ Nattom Cleat "or the like can be used.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

Example 1 A unit amount of each material was set to cement 3
60kg / m ^3, coarse aggregate 734kg / m ^3, fine aggregate 1089kg / m
³ and water of 191 kg / m ^3, and a high-performance water reducing agent in an amount shown in Table 1 was mixed with 100 parts by weight of cement to give a shotcrete. For this shotcrete, slump and compressive strength were measured. However, n of the present copolymer calcium salt in the used material is n in the chemical formula (1). Table 1 shows the results.

(Materials used) Cement: Commercial ordinary Portland cement Specific gravity 3.1
6 Coarse aggregate: gravel from Sakaikawa, Toyama Prefecture, surface dry condition, maximum dimension 15 mm
Below, specific gravity 2.64 Fine aggregate: river sand from Sakaigawa, Toyama prefecture, surface dry state, maximum dimension 5 mm or less, specific gravity 2.61 water: tap water, 20 ° C High performance water reducing agent: calcium salt of the copolymer, methoxy polyethylene Glycol vinyl ether-maleic acid copolymer calcium salt, n = 45, weight average molecular weight 2000
0, powder, particle size 200 μm or less High-performance water reducing agent: calcium salt of the present copolymer, calcium salt of methoxypolyethylene glycol vinyl ether-maleic acid copolymer, n = 10, weight average molecular weight 2000
0, powder, particle size of 200 μm or less High-performance water reducing agent: calcium salt of the present copolymer, calcium salt of methoxypolyethylene glycol allyl ether-maleic acid copolymer, n = 10, weight average molecular weight 2,000
0, powder, particle size 200 μm or less High-performance water reducing agent: Commercially available naphthalene sulfonate-based high-performance water reducing agent, powder High-performance water reducing agent: Commercially available melamine-based high-performance water reducing agent, powder High-performance water reducing agent: Commercial High-performance water reducer containing methoxypolyethylene glycol methacrylate-methacrylic acid copolymer salt as a main component, aqueous solution High-performance water reducer: styrene-maleic acid copolymer salt, weight average weight 40000, powder, particle size 200 μm Less than

(Measurement method) Slump: Measured according to JIS A1101. Compressive strength: Concrete was poured into a mold having a diameter of 10 cm and a length of 20 cm, molded, cured, removed from the mold, cured at 20 ° C in water, and measured with a 20-t pressure resistance tester. Weight average molecular weight: measured by aqueous GPC. The weight average molecular weight used a known polyethylene glycol as a standard substance.

[0047]

[Table 1]

Example 2 Same as Example 1 except that 100 parts by weight of cement, 0.3 part by weight of a high-performance water reducing agent, and the setting accelerator in the amounts shown in Table 2 were mixed to give shotcrete. It was carried out. Table 2 shows the results. (Material used) Setting accelerator A: Commercial sodium aluminate Setting accelerator B: Commercial sodium carbonate Setting accelerator C: Commercial alum

[0049]

[Table 2]

Example 3 A unit amount of each material was set to cement 3
60kg / m ^3, coarse aggregate 734kg / m ^3, fine aggregate 1089kg / m
³ and water of 191 kg / m ^3, and a high-performance water reducing agent in an amount shown in Table 3 was mixed with 100 parts by weight of cement to form sprayed concrete.
280 ". From one of the Y-shaped pipes provided on the way, 10 parts by weight of a quick-setting binder consisting of calcium aluminate is mixed with 100 parts by weight of cement, and the mixture is pressure-fed by a quick-setting additive adding machine "Denkan Atom Cleat". As a result, quick-setting shotcrete was prepared. The quick-setting sprayable concrete is 3.5 m high at a spraying speed of 4 m ³ / h for 30 minutes.
m, a mock tunnel having a width of 2.5 m was sprayed, and the amount of dust and the rebound rate were measured. Table 3 shows the results. (Material used) Calcium aluminate: Main component C
₁₂ A ₇ , Blaine value 6100 cm ² / g, specific gravity 2.90 (Measurement method) Dust amount: Every 10 minutes after the start of spraying, it was measured at a fixed position 3 m from the spraying place. Rebound rate: After the spraying was completed, the amount of shotcrete dropped without adhering was measured, and (rebound rate) = (weight of shotcrete dropped without adhering to the simulated tunnel at the time of spraying) / (blowing It was calculated from the formula of (weight of shotcrete used for attachment) x 100 (%).

[0051]

[Table 3]

Example 4 100 parts by weight of cement and 0.3 part by weight of a high-performance water reducing agent were mixed to give a shotcrete, and a quick setting agent composed of calcium aluminate is shown in Table 4 with respect to 100 parts by weight of cement. The same procedure as in Example 3 was carried out except that the amounts were mixed to form a quick-setting spray concrete, and the compressive strength was measured. Table 4 shows the results. (Measurement method) Compressive strength: The prepared shotcrete was sprayed on a pullout mold having a width of 25 cm x a length of 25 cm and a mold having a length of 50 cm x a width of 50 cm x a length of 20 cm. The material age of 3 hours was measured using a pull-out form specimen. The pins are covered with sprayed concrete from the surface of the pull-out formwork, the pins are pulled out from the back side of the formwork, the pullout strength at that time is obtained, and the compression is calculated from the formula of (compression strength) = (pullout strength) × 4 / (specimen surface area). The intensity was calculated. After 1 day of age, a specimen of 5 cm in diameter and 10 cm in length collected from a mold having a width of 50 cm, a length of 50 cm and a thickness of 20 cm was measured with a 20-ton pressure machine to determine the compressive strength.

[0053]

[Table 4]

Example 5 100 parts by weight of cement and 0.3 part by weight of a high-performance water reducing agent were mixed to give a shotcrete, and 100 parts by weight of calcium aluminate and a setting accelerator shown in Table 5 were mixed. Except that the binder was mixed with 10 parts by weight with respect to 100 parts by weight of cement to give a quick setting shotcrete, the same procedure as in Example 3 was carried out, and the compressive strength at a predetermined age was determined according to the method of Example 4. It was measured. Table 5 shows the results.

[0055]

[Table 5]

(Example 6) 100 parts by weight of cement and 0.3 part by weight of a high-performance water reducing agent were mixed to give a shotcrete, and a quick setting agent obtained by mixing 100 parts by weight of calcium aluminate and 10 parts by weight of a setting accelerator A was used. The same procedure as in Example 3 was carried out, except that the amount shown in Table 6 was mixed with 100 parts by weight of the cement to give a quick-setting sprayable concrete, and the compressive strength was measured according to the method of Example 4. Table 6 shows the results.

[0057]

[Table 6]

(Example 7) Unit amounts of each material were the same as those in Example 1, and 100 parts by weight of cement and 0.3 part by weight of a high-performance water reducing agent were used, using coarse and fine aggregates in a surface-dry state. Was mixed to prepare dry concrete, which was then carried into a spraying machine by a belt conveyor. On the other hand, 10 parts by weight of a quick setting agent obtained by mixing 100 parts by weight of calcium aluminate and 10 parts by weight of the setting accelerator A was added to dry concrete on a belt conveyor on the basis of 100 parts by weight of cement. Dry concrete to which the quick setting agent was added was pneumatically fed from a spraying machine, and water was added by a Y-tube so as to be 50 parts by weight with respect to 100 parts by weight of cement. 4 was measured. As a result, it was possible to carry out the spraying work without any trouble such as blockage of the pipe.
The compressive strength at the age of 3 hours at that time compressive strength of 1.3N / mm ^2, 28 days was 33.4N / mm ^2.

When the amount of dust at this time was compared with the case where no high-performance water reducing agent was added, it was 29.6 mg / m ³ when the high-performance water reducing agent was not added. Was 19.6 mg / m ³ , and the amount of dust generation was clearly smaller when the high-performance water reducing agent was added.

Example 8 100 parts by weight of cement, 0.3 part by weight of a high-performance water reducing agent, and a setting retarder in an amount shown in Table 7 were mixed to give a shotcrete, and 100 parts by weight of calcium aluminate and a setting accelerator were mixed. Example 3 was carried out in the same manner as in Example 3, except that 10 parts by weight of the quick setting agent mixed with 10 parts by weight of Agent A was mixed with 100 parts by weight of cement to give a quick setting sprayable concrete. 4 was measured. Table 7 shows the results. (Material used) Setting retarder α: Commercial citric acid Setting retarder β: Commercial potassium carbonate Setting retarder γ: Mixture of commercially available citric acid 3 and potassium carbonate 7 (weight ratio) Setting retarder δ: Commercial ethylene glycol Retarder ε: commercial sodium tripolyphosphate setting retarder: commercial sodium borate

[0061]

[Table 7]

Example 9 100 parts by weight of cement, 0.3 part by weight of a high-performance water reducing agent, and the dust reducing agent in the amounts shown in Table 8 were mixed to give shotcrete, and 100 parts by weight of calcium aluminate and accelerated setting. The same procedure as in Example 3 was carried out, except that 10 parts by weight of the quick setting agent mixed with 10 parts by weight of the agent A was mixed with 100 parts by weight of cement to give a quick setting sprayable concrete. Was measured. Table 8 shows the results. (Materials used) Dust reducer a: Commercial methyl cellulose Dust reducer A: Commercial hydroxypropyl cellulose

[0063]

[Table 8]

Example 10 100 parts by weight of cement, 0.3 parts by weight of a high-performance water reducing agent, and ultrafine powder in the amounts shown in Table 9 were mixed to give shotcrete, and 100 parts by weight of calcium aluminate and a setting accelerator were mixed. A rebound rate was measured in the same manner as in Example 3, except that 10 parts by weight of A, which was mixed with 10 parts by weight of A, was mixed with 100 parts by weight of cement to obtain quick-setting sprayable concrete. Table 9 shows the results. (Materials used) Ultrafine powder a: Commercially available silica fume, average particle size of 10 μm or less Ultrafine powder b: Commercially ground blast furnace slag, average particle size 10 μm
m or less

[0065]

[Table 9]

(Example 11) 100 parts by weight of cement, 0.3 parts by weight of a high-performance water reducing agent, and fibers in the amounts shown in Table 10 were mixed to give shotcrete, and 100 parts by weight of calcium aluminate and a setting accelerator A10 The impact resistance was measured in the same manner as in Example 3, except that 10 parts by weight of the quick-setting admixture was mixed with 100 parts by weight of cement to give a quick-setting sprayable concrete. Table 1 shows the results
0 is shown. (Materials used) Fiber i: Commercial vinylon fiber, fiber length 10 mm Fiber ii: Commercial steel fiber, fiber length 30 mm (Measurement method) Impact resistance: Shotcrete after 3 hours of age is 20 cm wide by 20 cm long. Place a piece of paper cut to a thickness of 2.5 cm on leveled standard sand and weigh 100 cm.
g spheres were dropped from a height of 50 cm. 5 drops
The sample that was broken within the number of times was rated X, the sample that was cracked without breaking was rated as ○, and the sample that was cracked without breaking was rated as ◎.

[0067]

[Table 10]

Example 12 Table 11 shows the unit amount of cement.
The amount of water used is the amount shown in Table 11 with respect to 100 parts by weight of cement, and 100 parts by weight of cement and 0.3 part by weight of a high-performance water reducing agent are mixed to give shotcrete, and calcium aluminate 100 Example 3 was carried out in the same manner as in Example 3 except that a quick-setting admixture obtained by mixing 10 parts by weight of the setting accelerator A with 10 parts by weight was mixed with 100 parts by weight of cement to obtain a quick-setting sprayable concrete. . Regarding shotcrete, the slump immediately after kneading was measured. Table 11 shows the results.

[0069]

[Table 11]

[0070]

By using the spraying material of the present invention, even if it becomes necessary to knead the sprayed concrete due to troubles of the spraying machine, etc., the flowability is large for a long time, the strength is increased, the dust is reduced, and the rebound is reduced. Excellent spray concrete and quick setting spray concrete can be obtained. Further, since the spray material of the present invention is a powder, it can be premixed with cement or various cement admixtures in advance, thereby improving workability and adjusting a higher quality spray material. Further, even when used in combination with a cellulosic dust reducing agent, the water reducing effect and the dispersing effect can be maintained, and the inhibition of strength development can be suppressed.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 55/00 C08L 55/00 E21D 11/10 E21D 11/10 D (72) Inventor Masahiro Iwasaki 2209 Aomi, Aomi-cho, Nishikubiki-gun, Niigata Electric Chemical Industry Co., Ltd.

Claims (6)

[Claims] Claims: 1. A cement and a powdery polycarboxylic acid-based high-performance water reducing agent comprising a calcium salt of a copolymer of polyalkylene glycol monoalkenyl ether and maleic acid represented by the chemical formula (1). A spraying material characterized by: Embedded image 2. A cement, comprising a powdery polycarboxylic acid-based high-performance water reducing agent comprising a calcium salt of a copolymer of a polyalkylene glycol monoalkenyl ether represented by the chemical formula (1) and maleic acid, and calcium aluminate. The spray material according to claim 1 or 2, further comprising a quick setting agent. 3. The spray material according to claim 1, wherein a = 0 in the chemical formula (1). 4. A spray material according to claim 1, wherein said quick-setting agent further comprises a setting accelerator. 5. The composition according to claim 1, further comprising one or more admixtures selected from the group consisting of a setting retarder, a dust reducing agent, an ultrafine powder, and a fiber.
Spray material as described. 6. A spraying method comprising using the spraying material according to claim 1.