JP2006225172A - Spray material and spray construction method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spray material comprising less alkali amount and excellent in initial strength development, and to provide a spray construction method using the same. <P>SOLUTION: This spray material containing a liquid quick-setting agent and cement concrete is characterized by using, in combination, an aluminum sulfate powder and an acidic-liquid quick-setting agent containing aluminum, sulfur and fluorine, or containing aluminum, sulfur and an alkanolamine, alternatively containing aluminum, sulfur, fluorine and an alkanolamine. The invention also relates to the spray construction method comprising spraying the above spray material on the natural ground. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spraying material sprayed onto an exposed natural ground surface in a slope or a tunnel such as a road, a railway, and a waterway, and a spraying method using the same.

  Conventionally, in order to prevent collapse of exposed ground in tunnel excavation work or the like, a method of spraying quick setting concrete in which a powder quick setting agent is mixed with concrete has been used (Patent Document 1, Patent Document). 2).

As the quick setting agent used in these spraying methods, a mixture of calcium aluminate or alkali metal carbonate or the like with calcium aluminate has been used because of its excellent quick setting performance.
However, a quick setting agent having a lower pH value than a quick setting agent obtained by mixing calcium metal aluminate, alkali metal carbonate, or the like with calcium aluminate, is required to have a weak alkalinity, preferably a neutral or weak acid setting agent. It was.

In order to solve this problem, the liquid accelerating agent is mainly composed of a basic aluminum salt or an organic carboxylic acid (see Patent Document 3), and mainly composed of aluminum sulfate or alkanolamine (see Patent Document 4). In addition, a basic aqueous solution of aluminum, lithium silicate, and lithium aluminate as main components (Patent Document 5) are used.
However, this liquid quick-setting agent is difficult to obtain an initial strength, and there is a risk of peeling off when blown thickly in a tunnel pit, compared to conventional powder-based quick setting agents.
In recent years, the development of a liquid quick-setting agent that has less influence on the human body than conventional basic quick-setting agents and is excellent in initial strength development has been awaited.
Japanese Patent Publication No. 60-004149 JP 09-019910 A Special table 2001-509124 Japanese Patent Laid-Open No. 10-087358 JP 2001-130935 A

  As a result of various studies to solve the above problems in view of the above situation, the present inventor can obtain a spray material having a small amount of alkali and excellent initial strength development by using a specific spray material. As a result, the present invention was completed.

The present invention relates to a spray material containing a liquid quick-setting agent and cement concrete, using an acidic liquid quick-setting agent containing aluminum, sulfur and fluorine in combination with powdered aluminum sulfate, containing aluminum, sulfur and alkanolamine. A spray material characterized by using a combination of an acidic liquid accelerator and powdered aluminum sulfate, and using an acidic liquid accelerator containing aluminum, sulfur, fluorine and alkanolamine in combination with powdered aluminum sulfate . Furthermore, the spraying agent characterized in that the liquid accelerator contains a complex-forming agent, the liquid accelerator contains an alkali metal element, and the pH of the liquid accelerator is 6 or less. The spray material is characterized in that the amount of the liquid quick-setting agent used is 5 to 15 parts with respect to 100 parts of cement. The powdered aluminum sulfate is 1 to 10 parts relative to 100 parts of cement in cement concrete, and the powdered aluminum sulfate has an n _{2 of} Al ₂ (SO ₄ ) ₃ · nH ₂ O of 5 to 20. This spray material is characterized by the above. Moreover, it is set as the spraying method characterized by spraying to a natural ground using this spraying material.

  By adopting the spraying material of the present invention and the spraying method using the same, it is excellent in quick setting even when a liquid quick-setting agent is used, and has an effect of preventing peeling after spraying.

Hereinafter, the present invention will be described in detail.
The cement concrete referred to in the present invention is a general term for cement paste, mortar, and concrete.
Further, parts and% in the present invention are based on mass unless otherwise specified.

The liquid quick-setting agent of the present invention is an acidic liquid quick-setting agent and preferably has a pH of 6 or less.
The main components of the liquid quick setting agent are aluminum (Al ₂ O ₃ ) and sulfur (SO ₃ ), and additionally contain fluorine, alkanolamine, a complex-forming agent, an alkali metal, and the like.

  What contains the fluorine component used for the liquid quick setting agent of this invention is not specifically limited, As what contains a fluorine, if it is a compound which melt | dissolves or disperses in water, it will not specifically limit. , Fluoride salts, silicofluoride salts, boron fluoride salts, organic fluorine compounds, and fluorine compounds such as hydrofluoric acid, and one or more of them can be used.

Examples of the fluoride salt include lithium fluoride, sodium fluoride, potassium fluoride, calcium fluoride, aluminum fluoride, and cryolite.
Cryolite can be either natural or synthetic.
Examples of the silicofluoride include ammonium silicofluoride, sodium silicofluoride, potassium silicofluoride, and magnesium silicofluoride.
As boron fluoride salts, boron fluoride, boron trifluoride, boron trifluoride monoethylamine complex, boron trifluoride acetic acid complex, and boron trifluoride triethanolamine, ammonium borofluoride, sodium borofluoride, potassium borofluoride , And ferrous borofluoride.

In the present invention, fluoride salt, silicofluoride salt, or hydrofluoric acid is preferable from the viewpoints of high safety, low production cost, and excellent coagulation properties.
The amount of fluorine, relative to SO ₃ 100 parts of a liquid quick-setting admixture is preferably 2.5 to 50 parts.

The alkanolamine used in the liquid accelerator of the present invention is an organic compound having an N—R—OH structure in the structural formula.
Here, R is an atomic group called an alkyl group or an allyl group, for example, a linear alkyl group such as a methylene group, an ethylene group, and an n-propylene group, an alkyl group having a branched structure such as an isopropyl group, In addition, an allyl group having an aromatic ring such as a phenyl group or a benzyl group is exemplified.
R may be bonded to the nitrogen atom at two or more locations, and a part or all of R may have a cyclic structure.
Furthermore, R may be bonded to a plurality of hydroxyl groups, and an element other than carbon or hydrogen, for example, sulfur, fluorine, chlorine, oxygen, or the like may be included in part of the alkyl group.
Examples of such alkanolamines include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N, N-dimethylethanolamine, N, N-dibutylethanolamine, N- (2-aminoethyl) ethanolamine , Boron trifluoride triethanolamine, and derivatives thereof, etc., and one or more of these can be used in the present invention, of which diethanolamine, N, N-dimethylethanolamine, and A mixture thereof is preferred, and a mixture of diethanolamine and N, N-dimethylethanolamine is more preferred.
The amount of the alkanolamine used is preferably 2.5 to 75 parts with respect to 100 parts of SO ₃ in the liquid quick setting agent.

In addition, the liquid accelerator of the present invention can use a complex-forming agent for the purpose of improving storage stability.
Specific examples of the complex-forming agent include, for example, (1) monocarboxylic acids such as formic acid, acetic acid, and propionic acid, (2) oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, malein Dicarboxylic acids such as acid, fumaric acid and phthalic acid, (3) tricarboxylic acids such as trimellitic acid and tricarbaryl, (4) oxymonocarboxylic acids such as hydroxybutyric acid, lactic acid and salicylic acid, oxydicarboxylic acid of malic acid Acids, (5) aminocarboxylic acids such as aspartic acid and glutamic acid, (6) aminopolycarboxylic acids such as ethylenediaminetetraacetic acid (EDTA) and trans-1,2-diaminocyclohexanetetraacetic acid (CyDTA), (7) ethylenediaminetetraacetic acid (Methylenephosphonic acid) [EDTPO], ethylenediaminedi (methylenephosphonic acid) [EDDPO], nitrilotris ( Tylene phosphonic acid) [NTPO], 1-hydroxyethylidene-1,1'-diphosphonic acid [HEDPO] and other phosphonic acids, (8) condensed phosphoric acids such as phosphoric acid, tripolyphosphoric acid, hexametaphosphoric acid, (9) acetylacetone and Examples include diketones such as hexafluoroacetylacetone. In the present invention, one or more of these complex-forming agents can be used.
Of these, oxalic acid, malonic acid, succinic acid, and condensed phosphoric acids are preferred.
The amount of the complex-forming agent used is preferably 2.5 to 75 parts with respect to 100 parts of SO ₃ in the liquid accelerating agent.
The liquid quick setting agent of the present invention can contain other than the elements and components of the present invention within the range where the effects of the present invention are not significantly reduced due to the property of using various materials in combination.

The liquid quick setting agent of the present invention can contain an alkali metal for the purpose of improving the quick setting property.
The alkali metal feedstock is not particularly limited, but may be any water-soluble compound containing an alkali metal element, that is, lithium, sodium, potassium, rubidium, and cesium. Oxide, chloride, hydroxide, nitrate, nitrite, phosphate, silicate, aluminate, sulfate, thiosulfate, persulfate, sulfide, carbonate, bicarbonate, oxalic acid A salt, borate, fluoride, silicate, silicofluoride, alum, metal alkoxide, and the like can be used, and one or more of these can be used. Among these, sulfate, bicarbonate, oxalate, fluoride, silicofluoride, alum and the like are preferable.
The content of the alkali metal is preferably 2.5 to 50 parts with respect to 100 parts of SO ₃ in the liquid quick setting agent.

In addition, it is possible to use a known water-soluble hydration accelerator in combination with the liquid accelerator of the present invention.
Examples of the hydration accelerator include organic hydration accelerators such as formic acid or a salt thereof, acetic acid or a salt thereof, and lactic acid or a salt thereof, water glass, nitrate, nitrite, thiosulfate, and thiocyanic acid. It is possible to use inorganic hydration accelerators such as salts.

  The solid content in the liquid quick-setting agent is preferably 20 to 60%, more preferably 25 to 50%. If it is less than 20%, an excellent quick setting property may not be obtained, and if it exceeds 60%, the viscosity of the liquid is high and the pumpability of the pump may be deteriorated.

  The form of the liquid accelerating agent of the present invention is liquid and includes a suspension, and the size of the suspended particles in the suspension is not particularly limited, but from the dispersibility of the suspended particles. It is preferably 5 μm or less.

  5-15 parts are preferable with respect to 100 parts of cement, and, as for the usage-amount of the liquid quick setting agent of this invention, 7-10 parts are more preferable. If the amount of the liquid quick-setting agent used is less than 5 parts, excellent quick setting may not be exhibited, and if it exceeds 15 parts, long-term strength development may be deteriorated.

  The spray material of the present invention is a combination of a liquid quick-setting agent and powdered aluminum sulfate. Powdered aluminum sulfate can be preliminarily contained in the spray concrete used as a base, but it is mixed with water or the liquid quick setting agent immediately before the spray concrete is sprayed onto the ground. It is also possible to mix the material immediately before discharging concrete, and the latter method is preferable from the viewpoint of reducing dust.

The powdered aluminum sulfate used in the present invention has a chemical formula of Al ₂ (SO ₄ ) ₃ .nH ₂ O, Al ₂ (SO ₄ ) ₃ .14 to 18 H ₂ O and Al ₂ (SO ₄ ) ₃ .8H _2. O, anhydrous aluminum sulfate, and the like can be used, but n is preferably 5 to 20 because of good initial adhesion.

  1-10 parts are preferable with respect to 100 parts of cement, and, as for the usage-amount of the powdered aluminum sulfate of this invention, 1.5-5 parts are more preferable. If the amount of powdered aluminum sulfate used is less than 1 part, excellent rapid setting properties may not be exhibited or dripping may increase during spraying, and if it exceeds 10 parts, long-term strength development may be deteriorated.

  The cement used in the present invention is not particularly limited, and various portland cements such as normal, early strength, very early strength, moderate heat, and low heat, and blast furnace slag, fly ash, and limestone fine powder such as portland cement. Any of various mixed cements mixed with can be used. The ratio of the mixture and cement in the mixed cement is not particularly limited, and a mixture obtained by mixing these admixtures more than specified by JIS can be used.

  In the present invention, in addition to the above-mentioned materials and aggregates such as sand and gravel, water reducing agents, AE agents, thickeners, and admixtures or additives such as fibers do not substantially impede the purpose of the present invention. It is possible to use together in a range.

  As the water reducing agent, for example, all known water reducing agents such as lignin sulfonic acid, naphthalene sulfonic acid, and polycarboxylic acid can be used.

  The AE agent prevents frost damage of concrete.

  Thickeners improve the material separation resistance of aggregates, cement pastes, and other additives, for example, celluloses such as methylcellulose, carboxymethylcellulose, and cellulose ether, polyethylene oxide, polypropylene oxide, polybutylene oxide Polymers such as, acrylic polymers having acrylic acid, methacrylic acid, and ester copolymers as a main component can be used.

Fibers are used from the viewpoint of improving the impact resistance and elasticity of cement concrete, and both inorganic and organic materials can be used.
Examples of the inorganic fiber include glass fiber, carbon fiber, rock wool, asbestos, ceramic fiber, and metal fiber.
Examples of the organic fiber include vinylon fiber, polyethylene fiber, polypropylene fiber, polyacryl fiber, cellulose fiber, polyvinyl alcohol fiber, polyamide fiber, pulp, hemp, wood wool, and wood chip. From the viewpoint of properties, metal fibers and vinylon fibers are preferable.
The length of the fiber is preferably 50 mm or less and more preferably 5 to 30 mm in terms of pumpability and mixing properties. The aspect ratio of the fiber is not particularly limited.

  As the slope of the present invention or the tunneling method for the tunnel, any of the commonly used dry and wet spraying methods can be used. Among them, the wet spraying method is preferable in terms of the generation amount of dust.

  The liquid quick setting agent of this invention can improve quick setting property by heating in the range of 20 degreeC or more and 90 degrees C or less, and making it mix with cement concrete.

  The slump value and flow value of the cement concrete for spraying of the present invention are not particularly limited, and any value can be used as long as it can be constructed without any problem within the range of combinations of known construction systems.

A mortar was prepared using a blend of 1/3 cement / sand and 52% W / C, and using a water reducing agent to adjust the slump (SL) to about 15 cm.
5 parts of powdered aluminum sulfate is added to 100 parts of cement in the prepared mortar, and 10 parts of liquid quick setting agent shown in Table 1 is further mixed with 100 parts of cement and packed in a mold, and tested. Procter penetration resistance value was measured at an environmental temperature of 20 ° C. The results are also shown in Table 1.
For comparison, the same test was performed in a system that did not use powdered aluminum sulfate.

<Materials used>
Powdered aluminum sulfate (A): Aluminum sulfate 14-18 hydrate, raw material manufactured by Kishida Chemical Co., Ltd. A: Aluminum sulfate 14-18 hydrate, raw material manufactured by Kishida Chemical Co., Ltd. b: Fluorine / alkali metal feedstock, sodium fluoride, Kishida Chemical Made by the company, reagent grade 1 raw material c: alkanolamine, diethanolamine, manufactured by Kishida Chemical Co., Ltd., reagent grade 1 raw material d: complex forming agent, succinic acid, made by Kishida Chemical Co., reagent grade 1 raw material e: fluorine feedstock, Hydrofluoric acid (55%), manufactured by Kishida Chemical Co., Ltd., reagent grade 1 liquid quick setting agent: Each raw material was calculated to have the composition shown in Table 1 and mixed. Use a solution dissolved at 80 ° C. for 30 minutes. All the liquid quick setting agents were adjusted to contain 8 parts of Al ₂ O ₃ in 100 parts of the liquid quick setting agent.
Cement: Ordinary Portland cement, commercially available, density 3.15 g / cm ³
Sand: Himekawa, Niigata Prefecture, density 2.62 g / cm ³
Water reducing agent: Naphthalenesulfonic acid water reducing agent, commercial water: tap water

<Measurement method>
Proctor penetration resistance value: measured according to JSCE D-102-1999, material age 15 minutes

From Table 1, Experiment Nos. 1-2 to 1 in which a liquid accelerator containing aluminum (Al ₂ O ₃ ), sulfur (SO ₃ ), fluorine (F) and / or alkanolamine and powdered aluminum sulfate are used in combination. It can be seen that the material of Example 8 has a large Procter penetration resistance value of 15 minutes of age and is excellent in quick setting. In particular, as shown in Experiment Nos. 1-4 and 1-8, an excellent quick setting material can be obtained by containing both fluorine, alkanolamine and alkali metal.
On the other hand, the material of the comparative example of experiment No. 1-1 which does not contain fluorine (F) and / or alkanolamine in the liquid accelerator, and the experiments No. 1-9 and 1-10 which do not use powdered aluminum sulfate together 1-12, 1-13, and 1-14 were low in Procter penetration resistance value of 15 minutes of age, and did not exhibit excellent rapid setting properties.
In addition, even when not using powdered aluminum sulfate, when both fluorine, alkanolamine and alkali metal are included (Experiment No.1-11, 1-15), Although it is considerably high, as shown in Example 4, there is much sagging during spraying, which is not preferable.

  Implemented except that the liquid quick-setting agent in Experiment 1-8 in Table 1 was used in the amount shown in Table 2 for 100 parts of cement and 5 parts of powdered aluminum sulfate (a) was used for 100 parts of cement. Performed as in Example 1. The results are also shown in Table 2.

  From Table 2, it can be seen that as the amount of liquid quick setting agent increases, the Procter penetration resistance value for the age of 15 minutes increases and the quick setting improves, so the amount of liquid quick setting agent used is: 5 parts or more is preferable with respect to 100 parts of cement. However, even if it is used in excess of 15 parts, the rapid setting properties are saturated as in Experiment No. 2-4, and long-term strength development may be deteriorated. preferable.

  Implemented except that powdered aluminum sulfate in the amount shown in Table 3 was used for 100 parts of cement, and 10 parts of the liquid quick setting agent of Experiment No. 1-8 in Table 1 was used for 100 parts of cement. Performed as in Example 1. The results are also shown in Table 3.

  From Table 3, it can be seen that, as the amount of powdered aluminum sulfate used increases, the Procter penetration resistance value at a material age of 15 minutes increases, and the rapid setting improves. One part or more is preferable with respect to 100 parts. However, even if it is used in excess of 10 parts, the quick setting properties are saturated as in Experiment No. 3-4, and the long-term strength development may be deteriorated. preferable.

Concrete with unit cement amount 400kg / m ³ , water cement ratio = 50%, s / a = 65% was adjusted to about 15cm slump using water reducing agent, and 100 parts of cement powder aluminum sulfate shown in Table 4 3 parts and 8 parts of the liquid quick-setting agent used in Experiment No. 1-8 were sprayed into the simulated tunnel. The spray rate of spray concrete was 10 m ³ / h, and the liquid quick-setting agent and powdered aluminum sulfate were added together with 4 m ³ / h spray air from a branch pipe 1 m before the concrete discharge port. The results of confirming the adhesive properties are also shown in Table 4.

<Materials used>
Cement: Ordinary Portland cement, commercially available, density 3.15 g / cm ³
Fine aggregate: Himekawa, Niigata Prefecture, density 2.62 g / cm ³
Coarse bone: Himekawa, Niigata Prefecture, density 2.64 g / cm ³
Water: tap water reducing agent: polycarboxylic acid type water reducing agent liquid quick setting agent: Experiment No. 1-8 composition powder aluminum sulfate (A): aluminum sulfate 14-18 hydrate powder aluminum sulfate (I): aluminum sulfate 8 Salt water aluminum sulfate (U): anhydrous aluminum sulfate

As shown in Table 4, when the powdered aluminum sulfate hydrate is used in combination, the adhesion during spraying is good. The property was good.
On the other hand, when powdered aluminum sulfate was not used in combination, as shown in Experiment No. 4-1, there was much sagging during spraying, and the adhesion state was not good.

Claims (10)

  A spray material comprising a liquid quick-setting agent and cement concrete, wherein an acidic liquid quick-set agent containing aluminum, sulfur and fluorine is used in combination with powdered aluminum sulfate.   A spray material comprising a liquid quick-setting agent and cement concrete, wherein an acidic liquid quick-set agent containing aluminum, sulfur and alkanolamine is used in combination with powdered aluminum sulfate.   A spray material comprising a liquid quick-setting agent and cement concrete, wherein an acidic liquid quick-set agent containing aluminum, sulfur, fluorine and alkanolamine is used in combination with powdered aluminum sulfate.   Furthermore, the said liquid quick setting agent contains a complex formation agent, The spraying material as described in any one of Claims 1-3 characterized by the above-mentioned.   Furthermore, the said liquid quick setting agent contains an alkali metal element, The spraying material as described in any one of Claims 1-4 characterized by the above-mentioned.   The spray material according to any one of claims 1 to 5, wherein the pH of the liquid quick-setting agent is 6 or less.   The spraying material according to any one of claims 1 to 6, wherein an amount of the liquid quick-setting agent used is 5 to 15 parts with respect to 100 parts of cement in the cement concrete.   The spraying material according to any one of claims 1 to 7, wherein the powdered aluminum sulfate is 1 to 10 parts with respect to 100 parts of cement in the cement concrete. 9. The spray material according to claim 1, wherein n of Al ₂ (SO ₄ ) ₃ .nH ₂ O is 5 to 20 in the powdered aluminum sulfate. The spraying method characterized by spraying to a natural ground using the spraying material as described in any one of Claims 1-9.