Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
  • C04B40/0028—Aspects relating to the mixing step of the mortar preparation
  • C04B40/0039—Premixtures of ingredients
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators or shrinkage compensating agents
  • C04B22/06—Oxides, Hydroxides
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators or shrinkage compensating agents
  • C04B22/08—Acids or salts thereof
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators or shrinkage compensating agents
  • C04B22/08—Acids or salts thereof
  • C04B22/12—Acids or salts thereof containing halogen in the anion
  • C04B22/126—Fluorine compounds, e.g. silico-fluorine compounds
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators or shrinkage compensating agents
  • C04B22/08—Acids or salts thereof
  • C04B22/14—Acids or salts thereof containing sulfur in the anion, e.g. sulfides
  • C04B22/142—Sulfates
  • C04B22/148—Aluminium-sulfate
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
  • C04B2103/10—Accelerators; Activators
  • C04B2103/12—Set accelerators
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00034—Physico-chemical characteristics of the mixtures
  • C04B2111/00146—Sprayable or pumpable mixtures
  • C04B2111/00155—Sprayable, i.e. concrete-like, materials able to be shaped by spraying instead of by casting, e.g. gunite

Definitions

• the present invention relates to a liquid accelerator. Specifically, the present invention relates to a liquid accelerator which excels in accelerating effect and also excels in storage stability at lower temperatures and inhibitory effect of the alkali-aggregate reaction.
• a liquid accelerator which excels in accelerating effect and also excels in storage stability at lower temperatures and inhibitory effect of the alkali-aggregate reaction.
• alkali metal salts (sodium and potassium) of aluminate, silicic acid, carbonic acid, etc. have been widely used.
• alkaline accelerators which contains alkali metals such as sodium or potassium, may pose a risk of inducing alkali-aggregate reaction with the aggregates in concrete and, therefore, are not preferable in the viewpoint of durability of the concrete.
• sprayed concrete generally includes a large quantity of cement per unit area, and therefore a large quantity of alkali (sodium and potassium) is also induced from the cement. Further, since the ratio of fine aggregates is also large, there was a high probability of causing alkali-aggregate reaction.
• an accelerator which consists of nitrate, sulfate, glycolate, lactate, etc. of aluminum, a compound forming agent, and a corrosion inhibitor and which contains no alkalis and chlorides has been proposed (see, for example, patent document 2).
• an accelerator that contains aluminum salts, which contains aqueous fluorides, and sulfates, and that does not contain alkali metals and chlorides has been proposed (see, for example, document 3).
• a liquid accelerator containing aluminum, sulfur, sodium, and fluorine has been proposed (see, for example, patent document 4).
• an accelerator that consists of a fluoride-containing aqueous aluminum salt, which is obtained through the reaction between the aluminum hydroxides or aluminum oxides and hydrofluoric acid, and a sulfate-containing aqueous aluminum salt such as aluminum sulfate and basic aluminum sulfate, and that does not contain alkali metals and chlorides (see, for example, patent document 5).
• a fluoride-containing aqueous aluminum salt which is obtained through the reaction between the aluminum hydroxides or aluminum oxides and hydrofluoric acid
• a sulfate-containing aqueous aluminum salt such as aluminum sulfate and basic aluminum sulfate
• a liquid accelerator that contains aluminum sulfate, alkanolamine, alkylene diamine, hydrofluoric acid, and 1 to 8.5% by total alkali of alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium sulfate, potassium sulfate.
• this liquid accelerator excelled in accelerating effect and initial strength development, it had a problem in solution stability at low temperatures.
• Patent document 1 Japanese Patent Laid-Open No. 2001-130935.
• Patent document 2 Japanese Patent Laid-Open No. 2001-180994, US 6,514,327
• Patent document 3 Japanese Patent Laid-Open No. 2002-29801.
• Patent document 4 Japanese Patent Laid-Open No. 2002-47048.
• Patent document 5 Japanese Patent Laid-Open No. 2002-80250.
• Disclosure of the Invention [Problem to be Solved by the Invention] [0006] Accordingly, it is the object of the present invention to provide a liquid accelerator which excels in accelerating effect, and which also excels in storage stability at low temperatures and in inhibitory effect of alkali-aggregate reaction.
• the present invention relates to a liquid accelerator composed of a fluoride- containing aqueous aluminum salt, which is obtained through the reaction between aluminum sulfate and hydrofluoric acid, aluminum hydroxide, and one or more kinds of lithium salts selected from the group consisting of lithium hydroxides, lithium carbonates, and lithium sulfates.
• the present invention also relates to the above described liquid accelerator in which total alkali content is less than 1 %.
• the present invention relates to the above described liquid accelerator characterized in that 15 to 35 % by mass of aluminum sulfate, 1 to 5 % by mass of hydrofluoric acid, less than 15 % by mass of aluminum hydroxide, and 3 to 25 % by mass of one or more kinds of lithium salts selected from the group consisting of lithium hydroxides, lithium carbonates, and lithium sulfates are used for the total amount of the liquid accelerator.
• the present invention further relates to the above described liquid accelerator wherein the ratio A/S of the number of moles of A1 2 0 3 (A) to the number of moles of S0 3 (S) in the liquid accelerator is 0.35 to 1.0.
• the present invention further relates to the above described liquid accelerator wherein the source of SO 3 is one or more kinds of sulfuric compounds selected from the group consisting of sulfuric acids, aluminum sulfates, lithium sulfates, sodium sulfates, and potassium sulfates.
• the present invention further relates to the above described liquid accelerator wherein one or more members selected from the group consisting of to Cio organic monocarboxylic and dicarboxylic acids and the metallic salts thereof are contained.
• the present invention further relates to the above described liquid accelerator wherein one or more members selected from the group consisting of alkanolamine, alkylene diamine, and triamine are contained.
• the present invention further relates to the use of the above described liquid accelera- tor for sprayed mortar or concrete applied to a dry or wet spraying process.
• the present invention further relates to a process of dry or wet spraying wherein the above described liquid accelerator is added to a cement composition such as mortar or concrete in a transport pipe, a watering nozzle, or a spray nozzle either directly to the mixture by means of an accelerator feed device, or to the water content.
• the present invention further relates to a process of dry or wet spraying characterized in that the above described liquid accelerator is added to base mortar or concrete which is added with a high-range AE water-reducing agent and/or a retarder of polycarbonic acid base and which is applied to the spraying process.
• the liquid accelerator of the present invention enables to reduce the total alkali of the accelerator by using specific lithium salts and eliminates crystalline precipitation at low temperatures thereby providing excellent storage stability at low temperatures.
• the invention reduces the effect on the environment and human body during spraying operation and the like, and provides the inhibitory effect on the alkali-aggregate reaction.
• the accelerator of the present invention utilizes a fluoride-containing aqueous aluminum salt containing hydrofluoric acid, the accelerator provides a good spraying workability without raising the initial accelerating effect too high, thereby making it possible to prevent the exfoliation of concrete during concrete spraying and enable a thick deposit of concrete. Moreover, since the above described fluoride-containing aqueous aluminum salt is obtained by adding hydrofluoric acid to aluminum sulfate, the manufacturing of the accelerator poses low risk and safer than conventional ones. [The Best Mode for Carrying out the Invention] [0016] Hereinafter, the present invention will be described in more detail.
• the present invention is a liquid accelerator composed of a fluoride-containing aqueous aluminum salt, which is obtained through the reaction between aluminum sulfate and hydrofluoric acid, aluminum hydroxide, and one or more lithium salts selected from the group consisting of lithium hydroxides, lithium carbonates, and lithium sulfates, with the total alkali being less than 1 %, and preferably not more than 0.5%.
• the aluminum sulfate to be used in the present invention may be aluminum sulfate which is generally used as accelerating agent, and it may be either fully or partly hydrated.
• a typical grade is 17% aluminum sulfate (Al 2 (So ) 3 -14.3H 2 0)(the name is after the content of aluminum oxides) and, when using a different grade, a proper quantity may be calculated based on this grade.
• the content of aluminum sulfate is, as the amount of A1 2 (S0 4 ) 3 , 15 to 35 % by mass of the total liquid accelerator.
• the hydrofluoric acid to be used in the present invention is generally used as a HF aqueous solution of about 40 to 55 % by mass.
• the proportion of hydrofluoric acid (as HF) subjected to the reaction with aluminum sulfate is preferably 1 to 5 % by mass of the total liquid accelerator.
• the present invention utilizes a fluoride-containing aqueous aluminum salt which is obtained by the reaction between aluminum sulfate and hydrofluoric acid; it is preferable that aluminum sulfate of 15 to 35 % by mass is reacted with hydrofluoric acid of 1 to 5 % by mass, which would provide a good solution stability at low temperatures for a long term. Since the above described fluoride-containing aqueous aluminum salt is obtained by adding hydrofluoric acid to aluminum sulfate unlike a conventional manner in which aluminum compounds are added to hydrofluoric solution, its manufacturing poses low risk and is safer.
• the aluminum hydroxide to be used in the present invention may be amorphous aluminum oxide which is commonly used as accelerating agent, and which is preferably contained up to 15 % by mass of the liquid accelerator. It is also possible to use inexpensive crystalline aluminum hydroxides; however, those have a low solubility thereby leading to a decline of solution stability at low temperatures, and therefore can not provide the same level performance as that of the amorphous type.
• the lithium salt to be used in the present invention may be any of lithium hydroxide, lithium carbonate, and lithium sulfate, or may be combinations of one or more of them. The preferable proportion of the lithium salt is 3 to 25 % by mass of the total liquid accelerator.
• the content of the lithium ion in the liquid accelerator is preferably such that the molar ratio Li/Na is not less than 0.6 for the Na 2 0 equivalent introduced from the mortar or concrete to inhibit alkali-aggregate reaction. Moreover, in the practical use of the liquid accelerator, the content of the lithium ion in the liquid accelerator is preferably in the range of 0.01 to 1.0 % by the mass of the cement in the mortar or concrete. [0022]
• the liquid accelerator of the present invention has a ratio A/S: the number of moles of A1 2 0 3 (A) to the number of moles of S0 3 (S), of 0.35 to 1.0. The range is preferably 0.35 to 0.55, and when A/S is within this range, the liquid accelerator exerts an excellent initial strength development.
• the liquid accelerator of the present invention may utilize sulfuric compounds such as sulfuric acid, aluminum sulfate, lithium sulfate, sodium sulfate, and potassium sulfate as the source of SO 3 for controlling A/S.
• sulfuric compounds such as sulfuric acid, aluminum sulfate, lithium sulfate, sodium sulfate, and potassium sulfate
• sodium sulfate and potassium sulfate they may be used by an amount that total alkali is less than 1 %.
• the preferable proportion of the sulfuric compounds is 5 to 35 % by mass of the total liquid accelerator.
• the liquid accelerator of the present invention may contain Ci to Cio organic mono- and di-carboxylic acids and one or more metal salts thereof for the purpose of improving the initial strength of concrete.
• the Cj to C 10 organic mono- and di-carboxylic acids and metal salts thereof may be preferably formic acid, oxalic acid, and glycol acid as well as the metal salts thereof, and other acids such as acetic acid, propionic acid, succinic acid, citric acid and tartaric acid may also be used.
• the proportions of these components are preferably 1 to 10 % by mass, and more preferably 4 to 8 % by mass of the total liquid accelerator [0024]
• the liquid accelerator of the present invention may be combinations of one or more members of alkanolamine, alkylene diamine, and alkylene triamine.
• the components of these are preferably efhylenediamine, ethylene- triamine, diethanolamine or triethanolamine, and more preferably diethanolamine. These components are in the proportion of preferably 0.1 to 10 % by mass, and more preferably 0.1 to 8 % by mass of the total liquid accelerator.
• the liquid accelerator of the present invention can be prepared in a simple manner by mixing the above explained components in any order and stirring the mixture, final mixture having a pH of 2 to 8 and containing water of 40 to 70 % by mass.
• the suitable use of the liquid accelerator of the present invention is to add the liquid accelerator of the present invention into a cement composition such as mortar or concrete applied to conventional dry or wet spraying process.
• the liquid accelerator of the present invention may be added by the amount of 5 to 12 % by mass with respect to the mass of the cement in the cement composition, although this will vary depending on the applications.
• the present invention is a process of dry or wet spraying wherein the above described liquid accelerator is added to a cement composition such as mortar or concrete in a transfer pipe, watering nozzle, or a spraying nozzle either directly to the mixture by means of an accelerator feed device, or to the water content.
• the present invention is a process of spraying wherein the liquid accelerator is added by a method shown in [0027] to a base mortar or concrete which is added with high- range AE water-reducing agent and/or a retarder of polycarboxylic acid base and which is applied to the spraying process.
• the high-range AE water-reducing agent of polycarboxylic acid base of the present invention may be any commercially available one for general purpose uses.
• polycarboxylic acid base cement water-reducing agent having polyalkeyleneoxide group such as JP,A,58-38380 (copolymer of polyethylene glycol methacrylate and methacrylic acid), JP,A,62-70250(copolymer of polyethylene glycol methacrylate, methacrylic acid, and amide compound adduct having polyalkeyleneoxide of unsaturated carboxylic acid); and ones containing JP,A,05-213644 (copolymer of polyethylene glycol methacrylate and methacrylic acid), JP,A,05-238795 (copolymer selected from polyalkylene glycol diester base monomers having unsaturated bonds, acrylic acid base monomers and polyalkylene glycol monoester monomers having unsaturated bond) JP,A,09-286645 (copolymer of polyethylene glycol methacrylate, of which oxyethylene group has different chain lengths of
• the retarder in the present invention may be exemplified by phosphonic acid derivatives selected from the group consisting of aminotri(methylenephosphonic acid), amino- tri(methylenephosphonic acid) 5 sodium salt, l-hydroxyethylydene-l,l-diphosphonic acid, 1- hydroxyethylydene-l,l-diphosphonic acid 4 sodium salt, ethyl enedi- aminetetra(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid) calcium/sodium salt, hexamethylene-diaminetetra(methylenephosphonic acid), hexamethylene- diaminetetra(methylenephosphonic acid) potassium salt, diethylenetriamine- penta(methylenephosphonic acid), and diethylenetriaminepenta(methylenephosphonic acid) sodium salt; and hydroxycarbonic acid and the salts thereof selected from salicylic acid, citric acid, lactic acid, gluconic acid, tartaric acid, muconic
• Fig.l shows the results of initial strength for the cases in which the A/S ratio is varied.

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• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Inorganic Chemistry (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Fluid-Pressure Circuits (AREA)
• Lining And Supports For Tunnels (AREA)
• Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)
• Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
• Detergent Compositions (AREA)
• Materials Applied To Surfaces To Minimize Adherence Of Mist Or Water (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

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Cited By (12)

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Citations (5)

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• 2003
  • 2003-09-19 JP JP2003328772A patent/JP4452473B2/ja not_active Expired - Fee Related
• 2004
  • 2004-08-18 WO PCT/EP2004/009253 patent/WO2005028398A1/en not_active Ceased
  • 2004-08-18 ES ES04764239T patent/ES2378992T3/es not_active Expired - Lifetime
  • 2004-08-18 PL PL04764239T patent/PL1663909T3/pl unknown
  • 2004-08-18 PT PT04764239T patent/PT1663909E/pt unknown
  • 2004-08-18 EP EP04764239A patent/EP1663909B1/en not_active Expired - Lifetime
  • 2004-08-18 AT AT04764239T patent/ATE545621T1/de active
  • 2004-08-18 SI SI200431869T patent/SI1663909T1/sl unknown
  • 2004-08-18 US US10/571,728 patent/US7662230B2/en active Active
• 2006
  • 2006-04-07 NO NO20061591A patent/NO342117B1/no unknown

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