JP2007204302A - Modifying agent for concrete and method for modifying concrete product using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out modifying of a concrete product by forming a metal concrete. <P>SOLUTION: The present invention provides a modifying agent for a concrete which comprises as a main component an aqueous solution of a sulfide which is obtained by ionic bonding of any one kind of group I or group II metals or other alkali metal compounds or a mixture thereof and sulfur. The present invention also provides a modifying agent for a concrete which comprises as a main component an aqueous solution of a polysulfide of any one kind of group I or group II metals or other alkali metal compounds or a mixture thereof. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a concrete modifier and a method for modifying a concrete product using the same.

  Since concrete is a porous body resulting from a hydration reaction of cement, it is excellent in breathability and moisture permeability and has been widely used in various structures since ancient times.

  The structure using concrete immediately after construction shows strong alkalinity due to the presence of calcium hydroxide, which is a cement hydrate. Under the influence of carbon dioxide gas and acid rain, carbon dioxide enters the concrete structure and reacts with calcium hydroxide to produce calcium carbonate, which makes the concrete neutral. When the steel rods progress toward the inside of the concrete and reach the reinforcing bars, the reinforcing bars rust, reducing the strength of the reinforcing bars, and cracking occurs inside the concrete due to the volume expansion caused by the rusting, greatly reducing the strength of the concrete. .

As a method of preventing the strength reduction due to the neutralization of such a concrete structure, conventionally, an organic paint is applied to the surface of the concrete structure, and the surface of the concrete structure is coated with the paint, thereby carbon dioxide gas. And rainwater were prevented from entering the concrete (see, for example, Patent Document 1).
JP 7-41730 A

  However, even if the surface of a concrete structure is covered with an organic paint, the paint undergoes a chemical change over time and deteriorates over time, preventing the invasion of carbon dioxide and rainwater. May be reduced.

  Also, when the paint hardens on the concrete surface and cracks occur in the concrete structure, the hard paint also cracks, and carbon dioxide gas and rainwater enter from the cracks, increasing the strength of the concrete. There was a risk of reduction.

  Moreover, if the concrete surface is coated with a hardened paint, the breathability and moisture permeability inherent in the concrete are impaired.

  Therefore, in the present invention according to claim 1, a concrete mainly composed of a sulfurized aqueous solution in which sulfur is ion-bonded with any one of one or two kinds of metal bodies or other alkali metal bodies or a mixture thereof and sulfur. A modifier is provided.

  Moreover, in this invention which concerns on Claim 2, the modifier of concrete which has as a main component the aqueous solution of the polysulfide of any 1 type or 2 types of metal bodies or other alkali metal bodies, or these mixtures is used. It is to provide.

  According to a third aspect of the present invention, there is provided a method for modifying a concrete product, characterized in that a concrete product is produced by adding the concrete modifier according to the first or second aspect to cement. It is to provide.

  According to a fourth aspect of the present invention, there is provided a method for modifying a concrete product, wherein an existing concrete product is impregnated with the concrete modifying agent according to the first or second aspect. It is.

  Moreover, in this invention which concerns on Claim 5, the concrete modifier of the said Claim 1 or Claim 2 is impregnated until it reaches the reinforcing bar inherent in the said existing concrete product, It is characterized by the above-mentioned. A method for modifying a concrete product described in 1. is provided.

  And in this invention, it can be made into metal concrete with the metal body contained in a modifier, and concrete can be improved. As a result, effects such as higher density, higher strength, prevention of neutralization, improved acid resistance, rust prevention of internal rebar, reduction of water absorption rate, improved salt resistance, and improved freezing resistance can be obtained.

  The concrete modifier according to the present invention is mainly composed of a sulfurized aqueous solution in which sulfur is ion-bonded with any one of one or two kinds of metal bodies or other alkali metal bodies or a mixture thereof and sulfur. is there.

  Moreover, the concrete modifier according to the present invention is mainly composed of a polysulfide aqueous solution of one or two kinds of metal bodies or other alkali metal bodies or a mixture thereof.

  Moreover, the concrete modifier according to the present invention may be added with an aqueous solution of metal hydroxide or an aqueous solution containing fine particles of metal hydroxide to any one of the above or a mixed solution.

Here, the class 1 metal body refers to any one of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Indicates beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra), and other alkali metal bodies include slaked lime, quick lime, and these This refers to a substance such as a mixture or a substance that becomes alkali metalized by addition of water or heat. The aqueous sulfide solution is lithium sulfide (Li ₂ S), sodium sulfide (Na ₂ S), potassium sulfide (K ₂ S), rubidium sulfide ( rb ₂ S), cesium sulfide (Cs ₂ S), francium sulfide (Fr ₂ S), beryllium sulfide (BeS), magnesium sulfide (MgS), calcium sulfide (CaS), sulfide stolons Um (SrS), refers to an aqueous solution of barium sulphide (BaS), radium sulfide (RaS), and the aqueous solution of polysulfide, lithium sulfide (Li ₂ S _X), sodium sulfide (Na ₂ S _X), potassium sulfide ( K ₂ S _X ), rubidium sulfide (Rb ₂ S _X ), cesium sulfide (Cs ₂ S _X ), francium sulfide (Fr ₂ S _X ), beryllium sulfide (BeS _X ), magnesium sulfide (MgS _X ), calcium sulfide ( CaS _X ), strontium sulfide (SrS _X ), barium sulfide (BaS _X ), radium sulfide (RaS _X ) refers to an aqueous solution of x = 12 to 12, and the metal hydroxide is lithium hydroxide (Li ₂ OH), Sodium hydroxide (Na ₂ OH), potassium hydroxide (K ₂ OH), rubidium hydroxide (Rb ₂ OH), cesium hydroxide (Cs ₂ OH), francium hydroxide (Fr ₂ OH), beryllium hydroxide (BeOH) ), Magnesium hydroxide (MgOH), calcium hydroxide (CaOH), hydroxide It refers to trontium (SrOH), barium hydroxide (BaOH), and radium hydroxide (RaOH).

  In addition, a sulfurized aqueous solution in which one or two kinds of metal bodies or other alkali metal bodies or a mixture thereof and ion of sulfur are ion-bonded, or one or two kinds of metal bodies or other alkali metal bodies. An aqueous solution of polysulfide of any one of these or a mixture thereof, an aqueous solution of metal hydroxide, or an aqueous solution containing metal hydroxide fine particles can be produced using a known chemical reaction.

  In particular, as a method for stably and safely producing polysulfides (however, Sx (x = 6 to 12)), any one of potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide or a mixture thereof is used. There is a method in which sulfur and sulfur are reacted in an airtight container while stirring and mixing under high pressure of 98 ° C to 345 ° C without discharging steam.

For example, when calcium hydroxide and sulfur are used, they can be produced by mixing slaked lime, sulfur and water,
^{_{Ca (OH) 2 → Ca ++}} + 2OH -
Ca ⁺⁺ + S → CaS
Reaction occurs.
This CaS is
_{^{2CaS + 4OH - → H 2 S}} + Ca (OH) 2 + S + Ca + O 2
It becomes.

  Here, in the conventional manufacturing method, a part of hydrogen sulfide and oxygen was released to the atmosphere as steam, but in the present invention, this reaction is performed in a sealed container so that the steam is not discharged. .

Therefore, the above reaction proceeds accurately,
H ₂ S + Ca (OH) ₂ + S + Ca → Ca (HS) ₂ + Ca (OH) ₂
It becomes.

CaS is
2CaS + 2H ₂ O → Ca (HS) ₂ + Ca (OH) ₂
It becomes.

In addition, CaS
CaS + (x-1) S → CaSx
Thus, CaSx (x = 6) is stably generated.

  This is not limited to the case where calcium hydroxide is used, and even when potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide or a mixture thereof is used, Sx (x = 6) is contained. Can be stably produced.

  In particular, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide, or a mixture thereof and sulfur and potassium, magnesium, calcium, or sodium adhering to the surface of the sulfur particles are crushed and peeled off. By reacting while stirring and mixing, a treatment agent containing polysulfide (however, Sx (x = 6)) as a main component can be generated more stably.

  In addition, when the reaction is performed at a temperature equal to or higher than the melting temperature of sulfur, a treatment agent containing polysulfide (however, Sx (x = 8)) as a main component can be stably generated.

  In addition, when a predetermined amount of potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide or a mixture thereof is continuously mixed in a mixed solution of sulfur and hot water, polysulfide However, it is possible to stably produce a treatment agent mainly composed of Sx (x = 8 to 10).

  Moreover, slaked lime is mixed in a mixed solution of potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide or a mixture thereof and sulfur and hot water in a low temperature environment (−20 ° C. to 0 ° C.). In this case, a treatment agent containing a polysulfide (however, Sx (x = 6 to 12)) as a main component and containing a milky improver capable of solidifying the treatment object is stably generated. be able to.

  In addition, calcium is mixed in a mixed solution of potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide or a mixture thereof and sulfur and hot water in a low temperature environment (-30 ° C to -25 ° C). In this case, it is possible to stably produce a treatment agent containing polysulfide (however, Sx (x = 8)) as a main component.

  In addition, when sulfur pulverized to 100 μm or less (preferably 50 μm or less), potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydroxide or a mixture thereof is used in a powder or silt state Can stably produce a treating agent mainly composed of polysulfide (however, Sx (x = 10 to 12)).

  Moreover, the concrete modifier according to the present invention can be produced using alkaline ash as a raw material. For example, fly ash (coal species; generated by co-firing 50% Musselburg and 50% Drayton, alkalinity PH13.5) as alkali ash, 20 parts by weight fly ash, 20 parts by weight sulfur, 100 parts by weight water First, 20 parts by weight of fly ash and 100 parts by weight of water are placed in a reaction can, the top lid is closed, and the mixer is operated to mix for about 10 minutes.

Next, a safety valve is set, the exhaust pressure is set to about 10 kg / cm ² as the upper limit reaction pressure, the furnace body cooling drain valve and the cooling valve are opened, and the cooling water inlet valve is opened to allow water to flow.

Next, in order to suppress evaporation during the reaction, a preload of about 2.5 kg / cm ² is applied by pressurization with an air compressor.

Next, the burner is ignited, the pressure gauge and the thermometer are confirmed, and the temperature is raised while mixing. At this time, the pressure is set to 10 kg / cm ² or less, and after the thermometer display reaches 110 ° C., the mixture is reacted for about 30 minutes.

  Next, the burner is stopped and left until the pressure gauge is lowered. When the pressure gauge is stabilized, the final residual pressure is completely discharged by the exhaust valve and assimilated with the atmospheric pressure.

  Next, the mixer is stopped, the discharge valve is opened, the precipitate and liquid are discharged, and these are collected.

  Next, the recovered product is cooled and separated by precipitation to obtain a chemical solution and a precipitate. Here, 130 parts by weight of the chemical solution and 20 parts by weight of the precipitate could be obtained.

  The recovered chemical solution contained calcium polysulfide and was a yellow-green pH 10 liquid with a liquid specific gravity of 1.2 g / cc.

  Further, when incineration fly ash PH13.5 was used as a raw material, a brown pH 11 liquid having a liquid specific gravity of 1.15 g / cc containing calcium polysulfide was obtained.

  The liquid thus produced, and further an aqueous precipitate solution can be used as a modifier.

Thus, when a modifier is produced using fly ash, which is a substance containing calcium, magnesium, aluminum, and silica, as raw materials, gehlenite (2CaO · 2) is produced by calcium, magnesium, aluminum, and silica contained in the raw materials. _{Al 2 O 3 · SiO 2)} , Arno site _{(CaO · Al 2 O 3 ·} 2SiO 2), Merubinaito _{(3CaO · MgO · 2SiO 2)} , Akerumanaito _{(2CaO · MgO · 2SiO 2)} , Monte celite (CaO · MgO · SiO _2), rankinite Night (3CaO · 2SiO _2), dicalcium silicate (2CaO · SiO _2), crust Knight (CaO · SiO _2), Subineru _{(MgO · Al 2 O 3)} , leucite ((K ₂ O · A modifier comprising a heavy composition containing N ₂ O) .Al ₂ O ₃ .SiO ₂ ) can be produced.

  The above modifier may be used by adding to the cement during the production process of the concrete product to produce a concrete product, or can be used by impregnating an existing concrete product.

  When a concrete product is manufactured by adding the above-mentioned modifier to cement, or when an existing concrete product is impregnated, it can be converted into a metal concrete with a metal body contained in the modifier. Effects such as higher density, higher strength, prevention of neutralization, improved acid resistance, rust prevention of internal rebar, reduced water absorption, improved salt resistance, improved freeze resistance, and the like can be obtained.

  In particular, the amount of improving agent that reaches the surface of internal metal structures (including reinforcing bars) is applied to concrete that adheres to the surface of metal structures such as columns and beams, and concrete that has reinforcing bars inside. When impregnated or impregnated, the surface of the metal structure can be changed from a metal oxide to a metal sulfide, whereby the rust prevention effect of the metal structure can be obtained.

  Moreover, the penetration | permeation performance of an improving agent can be improved by apply | coating or impregnating to a concrete product after adding surfactant to an improving agent.

  In addition, by adjusting the specific gravity by adding moisture to the improver, the permeability and strength of the improver can be adjusted by applying or impregnating the concrete. For example, in the case of the above chemical solution containing calcium polysulfide, when emphasizing permeability rather than strength, adjust to 1.05 g / cc to 1.1 g / cc, and 1.1 g / cc to 1.2 g for normal use Adjust to / cc and adjust to 1.2g / cc to 1.35g / cc when emphasizing strength.

  Further, an aqueous solution of metal hydroxide or an aqueous solution containing metal hydroxide fine particles may be applied to or impregnated into a concrete product after being added to the modifier, and contains an aqueous metal hydroxide solution or metal hydroxide fine particles. The concrete solution may be applied or impregnated with the aqueous solution and the improving agent simultaneously sprayed onto the concrete product while being added to the improving agent.

  Moreover, the adhesion performance of the improving agent can be improved by applying or impregnating the concrete product after adding or adding the paste to the improving agent.

  Further, after applying or impregnating the improving agent to the concrete product, the concrete product may be fixed by crystallizing sulfur by natural drying or forced drying.

  In this case, the crystal of sulfur grows in a needle shape inside and on the surface of the concrete product, and the strength can be improved.

  In addition, even if a linear gap is formed by drying on the film of the improving agent formed on the surface of the concrete product, sulfur crystals grow into needles from this gap, and the gap can be closed. Also, the strength can be improved. Further, the gap can be completely closed by overcoating with a paint or the like to crush the needle-like crystal.

Claims (5)

  A concrete modifier comprising, as a main component, a sulfide aqueous solution in which sulfur is ion-bonded with any one of a type 1 or type 2 metal body or another alkali metal body or a mixture thereof and sulfur.   A concrete modifier comprising, as a main component, an aqueous solution of a polysulfide of any one of a type 1 or type 2 metal body or another alkali metal body or a mixture thereof.   A method for modifying a concrete product, wherein the concrete product according to claim 1 or 2 is added to cement to produce a concrete product.   A method for modifying a concrete product, comprising impregnating an existing concrete product with the concrete modifying agent according to claim 1 or 2.   5. The method for modifying a concrete product according to claim 4, wherein the concrete modifier according to claim 1 or 2 is impregnated to reach a reinforcing bar inherent in the existing concrete product.