KR100880932B1 - Producing method for ultra rapid hardening polymer modified concrete - Google Patents

Abstract

A manufacturing method of rapid hardening concrete composition reforming polymer is provided to optimize quality of ultra rapid hardening cement material in order to be suitable for physical properties of the rapid hardening concrete and to improve workability, strength, durability and profitability. A manufacturing method of rapid hardening concrete composition comprises steps of: mixing the rapid hardening cement composition and aggregate; mixing water and polymer modifier and manufacturing combined water; and mixing the combined water with a mixture of the aggregate and the rapid hardening cement composition. The rapid hardening cement composition includes powder 40~60 weight% produced by pulverizing Wien system clinker including calcium sulfoaluminate(3CaO.3Al2O3.CaSO4) 60~85 weight%, plaster powder 15~30 weight% in which anhydrous gypsum and hemihydrate are mixed, normal portland cement 20~40 weight% and calcium hydrooxide 1~4 weight%.

Description

PROCESSING METHOD FOR ULTRA RAPID HARDENING POLYMER MODIFIED CONCRETE

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of construction materials, and more particularly, to a method for producing superhard concrete used for emergency repair of an over-lay of a concrete pavement or bridge.

Repair work on the premise of blocking traffic on public roads causes traffic jams and a lot of inconvenience to users. Therefore, construction is usually done at night or at dawn when traffic is low, especially within 3 to 5 hours after construction commences. Fast concrete is used.

However, fast cement using cemented carbide has the advantage of rapid strength development.However, due to the characteristics of minerals in cemented cement, water resistance, freeze resistance, and long-term durability are weaker than general Portland cement. There are frequent problems.

Accordingly, in recent years, polymer superhard concrete using SBR latex, an acrylic resin, etc., which is a type of water-based polymer, has been actively used as a repair material to supplement the durability of concrete.

Concrete using this polymer has excellent resistance to freeze-thawing and scaling, and has high water resistance and adhesion, greatly compensating the disadvantages of using only cemented carbide, water, and aggregates, and greatly improving the quality of road repair work. Contributed.

Cement, which has been used for the manufacture of fast-hard concrete, can be roughly classified into three types depending on its composition.

First, a portland cement, gypsum and admixture are added to a clinker based on C ₁₁ A ₇ CF ₂ (11CaO.7Al ₂ O ₃ · CaF ₂ ), a calcium fluoroaluminate mineral (Registration No. 10-0033581). , 10-0005309, Japanese Patent Application Laid-Open No. 52-139819).

Secondly, Ca (CaOAl ₂ O ₃ ), C ₂ A (2CaOAl ₂ O ₃ ), C ₁₂ A ₇ Portland cement, gypsum and admixture are added to an alumina cement containing (12CaO.7Al ₂ O ₃ ) as a main component.

Third, the Awin-based clinker is a system containing calcium sulfoaluminate (3CaO.3Al ₂ O ₃ .CaSO ₄ ) as a main component (registration number 10-0755272, 10-0310657, 10-0220340, 10-0122033).

The third of these is the newest cemented carbide cement composition, which is easier to manufacture due to the lower firing temperature of clinker (1,200 ~ 1,350 ℃) compared to other technologies, and is usually used in combination with portland cement, gypsum and admixture. When properly adjusted, it is most commonly used because it shows excellent initial strength expression and stable long-term strength.

In addition, in the manufacture of fast-hard concrete, until now, it is simply used in the composition of the antifoaming agent, the coagulant retardant, the aggregate, and the water (Reg. No. 10-0403979) which is previously dissolved in the Irwin superhard cement, or the Irwin superhard cement. A method of using a mixture of latex with SBR latex and an acrylic resin (registered 10-0807850, 10-0696313) has been proposed, and a method of mixing fly ash, silica fume, blast furnace slag fine powder, etc. as a mixed material in cement ( 10-0696313, 10-0618297, publication 10-2005-0031097), and the like.

Cement for the manufacture of fast-hard concrete is usually designed to meet the commercial strength within 3 to 4 hours by mixing with water, but when used as a polymer concrete or mortar by mixing an aqueous polymer such as SBR latex or There is a big difference in the property expression properties.

In particular, the use of fly ash, slag powder, silica fume, etc., which is a slow reactivity as a mixture, may be advantageous in terms of long-term strength, but it is not an effective method in the art that requires initial strength.

Zinnia Strength Development of diameter cement mechanism and the Al ^{3 +} ion the reaction is eluted from the Ca ^{2 +} ions and calcium aluminate eluted from the like immediately after the contact with water, cement and calcium hydroxide, calcium aluminate hydrates (CaO · Al ₂ O ₃ NH ₂ O) is formed, followed by reaction with gypsum in cement to produce ethrinzite (3CaO.Al ₂ O ₃ .3CaSO ₄ .32H ₂ O), which hardens rapidly, thereby expressing strength early.

Therefore, the quality of cemented carbide cements, such as strength expression rate, strength expression rate, and workability, depend on the technology of controlling the rate and amount of ethrinzite mineral formation and the stability of hydrates.

Particularly, the components of Awin-based clinker minerals (3CaO · 3Al ₂ O ₃ · CaSO ₄ ) and some of gypsum, slaked lime and cement are highly reactive when mixed with water, causing active hydration reactions. In a few minutes, it will progress quickly.

In particular, ethrinzide hydrate combined with sulfate (SO ₄ ^2- ) is monosulfate (3CaO · Al ₂ O ₃ · CaSO ₄ · 12H ₂ O) and calcium when there is insufficient supply of each component that maintains its composition as an unstable hydrate. Transition to aluminate hydrate (CaO.Al ₂ O ₃ .nH ₂ O) or the like results in low strength expression.

When the polymer latex is mixed, the polymer forms a film on the surface of each component constituting the cemented carbide cement, and the hydration activity of these components is greatly reduced, resulting in unstable overall reactor.

Degradation of the hydration activity of cemented carbides delays the development of strength and appearance and prevents the practical strength and pot life of fast curing concrete required for rapid repair due to variations in workability such as quenching or delaying.

To improve this problem, Portland cement and Arwin-based clinker grinds have been artificially present in a specific amount of free CaSO ₄ during mineral formulations in order to enhance and reliably develop high strength initially at the mixture conditions where polymer latex is used. A method (Registration No. 10-0755272) prepared by appropriately mixing gypsum, a coagulation control agent, a curing accelerator and the like has also been proposed.

However, 1,250 ~ 1,350 ℃ sulfuric acid at O wingye clinker synthesis process of firing at a high temperature (SO ₄ ^{2 -)} is that the employment high volatility difficult, preferentially react with other alkali metal salts (Na ^+, K ⁺⁾ compared to the other components Due to the properties it is difficult to constantly present free CaSO ₄ in the clinker as required.

In particular, the free CaSO ₄ produced at a high temperature of about 1,300 ° C. is virtually unhydrated and is present in the form of anhydrous gypsum, known as dead stone gypsum, and thus is highly effective for the formation of ethrinzite in Awin cemented carbide. There is no impact.

Due to these characteristics, in order to obtain the required strength in the early stage of fast concrete production, a considerable amount of super fast cement must be used in the compounding design, which is pointed out as a problem in terms of economics of concrete compounding design.

The present invention is designed to solve the above problems, and unlike the conventional fast-concrete concrete composition for road repair using a polymer latex, the quality of the cemented carbide material used with the latex to meet the properties of the fast-hard concrete The purpose of the present invention is to propose a method for producing a polymer modified cemented carbide concrete composition having improved workability, improved strength, durability, and economic efficiency by optimizing to obtain an economical compounding composition.

The present invention is a dry blending step of mixing the cemented carbide composition and aggregate cemented carbide in order to achieve the object as described above; A premixing step of preparing a blended water by mixing water and a polymer modifier; It proposes a method for producing a polymer-modified cemented carbide concrete composition comprising; concrete mixing step of mixing the blended water to the mixture of the cemented carbide cement composition and aggregate.

The cemented carbide cement composition is 40 to 60% by weight of a powder obtained by grinding an Arwin-based clinker containing 60 to 85% by weight of calcium sulfo aluminate (3CaO.3Al ₂ O ₃ .CaSO ₄ ); 15 to 30% by weight of gypsum powder mixed with anhydrous gypsum and hemihydrate gypsum; Usually 20-40% by weight of Portland cement; Slaked lime 1 to 4% by weight; It is preferable to include.

It is preferable that the powder obtained by pulverizing the above-mentioned clinker has a specific surface area of 6,000 to 9,000 cm ² / g by blain.

The gypsum powder is preferably a mixture of 10 to 45% by weight of the hemihydrate gypsum with respect to 100% by weight of the anhydrous gypsum.

The gypsum powder is preferably a specific surface area of 7,000 ~ 9,000 cm ² / g by the blain.

It is preferable to further mix 0.3 to 1.0 weight% of a high fluidizing agent with respect to 100 weight% of said superhard cement compositions.

It is preferable to mix 0.2-1.0 weight% of coagulation delay agents with respect to 100 weight% of said superhard cement compositions.

It is preferable to mix 0.6-1.5 weight% of hardening accelerators with respect to 100 weight% of said superhard cement compositions.

It is preferable to mix 0.1-0.5 weight% of antifoamers further with respect to 100 weight% of said superhard cement compositions.

The polymer modifier preferably comprises SBR latex.

The mixing amount of the SBR latex is 11 to 17% by weight based on the solid content, based on 100% by weight of the cemented carbide composition.

When the minimum depth of the cross section to be repaired is 50 mm or less, with respect to 100% by weight of the cemented carbide cement composition, 168 to 200% by weight of the coarse aggregate having a maximum dimension of 13 mm; Fine aggregate 230 ~ 265% by weight of the aggregate; 17 to 23% by weight of the water; 26 to 36% by weight of the SBR latex; It is preferable to mix.

When the minimum depth of the cross section to be repaired is 50 mm or more, 195 to 230% by weight of the coarse aggregate having the largest dimension of the aggregate, based on 100% by weight of the cemented carbide cement composition; Fine aggregate 234 ~ 270% by weight of the aggregate; 15 to 20% by weight of the water; 24 to 34% by weight of the SBR latex; is preferably mixed.

The dry blending step is made by injecting coarse aggregate, the cemented carbide cement composition, fine aggregate into a forced pan mixer in order and performing dry rubbing, and the concrete manufacturing step by adding the blended water to the dry blended mixture. It is preferably made by rubbing for 60 to 90 seconds.

Unlike conventional hard latex concrete compositions for road repair using polymer latex, the present invention optimizes the quality of superhard cement material used with latex to meet the fast concrete requirements and results in economical formulation. By presenting a method for producing a polymer modified cemented carbide concrete composition improved workability, strength, durability, economics.

In particular, the present invention, unlike the conventional polymer latex modified cemented carbide concrete, the cemented cement material is used to efficiently hydrate the ethrinite and calcium aluminate to determine the initial strength and pot life in the polymer latex conditions The concrete blended using this cement has sufficient features to secure sufficient workability, and after that, the hydration reaction is rapidly activated to express strength quickly and reach the common strength early.

In addition, by providing a composition with a different maximum particle size of the coarse aggregate according to the repair section of the road or bridge slab, it is possible to reduce the cracks and economical concrete configuration.

In the preparation of concrete of such a composition, water and latex are used in a premixed form, so that the wetting property of the cemented carbide component is improved, thereby improving the stirring performance of the concrete and achieving high quality.

Hereinafter, embodiments of the present invention will be described in detail.

The method for producing a polymer modified cemented carbide concrete composition according to the present invention basically comprises a dry blending step of mixing cemented carbide cement composition and aggregate; A premixing step of preparing a blended water by mixing water and a polymer modifier; It is configured to include; concrete mixing step of mixing the blending water to the mixture of cemented carbide cement composition and aggregate.

Since a polymer modifier such as latex has a high viscosity, when mixing cemented carbide, aggregate, water, and modifier at once, there is a problem in that the mixing operation is difficult and the superhard diameter performance is hardly obtained.

Therefore, according to the present invention, a method of preparing concrete by mixing water and a polymer modifier separately and mixing the same with a dry-blended cement-aggregate mixture provides a superior super speed while reducing the amount of cemented carbide. This is to achieve light performance.

The cemented carbide cement composition used in the present invention comprises 40 to 60% by weight of a powder obtained by pulverizing an Arwin-based clinker containing 60 to 85% by weight of calcium sulfo aluminate (3CaO.3Al ₂ O ₃ .CaSO ₄ ); 15 to 30% by weight of gypsum powder mixed with anhydrous gypsum and hemihydrate gypsum; Usually 20-40% by weight of Portland cement; It is preferable that it is comprised including; 1-4 weight% of slaked lime.

More excellent physical properties when 0.3 to 1.0% by weight of the high fluidizing agent, 0.2 to 1.0% by weight of the coagulation delay agent, 0.6 to 1.5% by weight of the curing accelerator, and 0.1 to 0.5% by weight of the antifoaming agent are further included with respect to 100% by weight of the mixed composition. Can be obtained.

The main components of the Arwin-based clinker are calcium sulfo aluminate (3CaO · 3Al ₂ O ₃ · CaSO ₄ ), dicalcium silicate (2CaO · SiO ₂ ), and calcium aluminate minerals (12CaO · 7Al ₂ O ₃ , CaO · Al ₂ O ₃ , ₂ CaO-Al ₂ O ₃ .SiO ₂ ), and trace amounts of calcium ferrite (4CaO-Fe ₂ O ₃ ) and the like are present.

The calcium sulfoaluminate mineral content of the Irwin clinker used is generally 45 to 60% by weight, and Al ₂ O _{3 preferably} contains 32 to 38% by weight.

Irwin-based clinker is slightly hydrated by the film coating when using the polymer latex, so it is better to increase the powder to increase the surface area of the reaction compared to the water alone.

In the case of the present invention, the specific surface area by the blain was found to be an appropriate particle size between 6,000 and 9,000 cm ² / g.

If the specific surface area is less than 6,000, the strength expression is delayed and the strength level is lowered, while if the specific surface area is higher than 9,000cm ² / g, the pot life is shortened, and the use of the coagulation delay agent for securing workability is greatly increased. This is because a phenomenon in which the strength expression is lowered appears.

The composition according to the present invention is made by mixing 15 to 30% by weight of gypsum powder mixed with anhydrous gypsum and hemihydrate gypsum with respect to 40 to 60% by weight of the Awin-based clinker pulverized to the appropriate powder as described above.

In a hydration reaction mechanism in which cement exhibits rapid hardening, the rapid coagulation and the common strength exerted within a few hours are mainly dependent on the formation reaction of ethrinzite hydrate.

These eth- Lin Xi generated in the tree hydrate ah calcium aluminate of calcium sulfo aluminate major component of wingye clinker minerals (nCaO · mAl ₂ O ₃₎ and gypsum and calcium being eluted from the Portland cement component (Ca ^{2 +),} sulfur (SO ₄ ^{2 -)} depends on the content ratio of.

Among these components, in particular sulfate (SO ₄ ^2- ) is the catalyst that governs the overall reaction.

The calcium aluminate component generates a C ₃ AnH ₂ O (n = 6 ~ 12) hydrate called hydrogarnet, which causes a rapid exothermic reaction upon contact with water, followed by reaction with gypsum (3CaO · Al ₂ O _3). 3CaSO ₄ 32H ₂ O).

However, sulfur (SO ₄ ^{2 -)} in a liquid phase when the concentration of the degradation is broken down into _{monosulfate (3CaO · Al 2 O 3} · CaSO 4 · 12H 2 O).

In the reaction between calcium aluminate and gypsum, the form of the hydrate depends on the molar ratio of these components. When the gypsum / calcium aluminate molar ratio is 3 or more, it is maintained as ethrinzide hydrate, and the molar ratio is 3.0 to 1.0, and the gypsum content is low. If the molar ratio is 1.0, monosulfate is present, and if it is less than 1.0>, it is present as a hydrogarnet (C ₃ AnH ₂ O) hydrate.

In addition, when the content of lime (Ca ^{2 +} ) in the solution component is small, some remain as Al (OH) ₃ .

Monosulfate hydrate does not contribute to strength due to weak bond strength of hydrate in the form of hexagonal plate, and it is a function of Al (OH) ₃ degree gel hydrate coated on calcium silicate component to inhibit their hydration and hinder its strength expression. Do it.

Therefore, under the conditions of using polymer latex together in superhard cement using an Awin-based clinker, the hydration reactions in which ethrinite is produced are delayed, so it is necessary to accelerate the reaction rate and adjust the activity appropriately. have.

To this end, the present invention focuses the invention on the presence of gypsum that acts as a catalyst for reaction rate and its mechanism.

In some cases, there was a method using the gypsum component contained in the clinker, but in the related art, gypsum, known as natural anhydrite, was simply added in terms of coagulation control, but was not used for the reaction mechanism and effect of the component.

The type of gypsum is classified as follows according to the heat treatment conditions, and the reactivity of the gypsum depends on the solubility of each gypsum.

The solubility of gypsum is 2.08 g / l of gypsum gypsum, 6.20 g / l of α hemihydrate gypsum, 8.15 g / l of β hemihydrate gypsum, 6.30 g / l of water soluble anhydrite and 2.70 g / l of natural anhydrite gypsum. The resulting I-type anhydrous gypsum, also known as dead stone gypsum, has little reactivity.

Gypsum, which is one of the components of Irwin cemented carbide, is generally made of natural anhydrous gypsum, which is slightly more active than dihydrate gypsum. There will be no.

Therefore, in order to manufacture a fast cement composition, an excessive amount of gypsum must be added, but there is a limit in variation of the gypsum content in the overall component composition ratio.

In order to stably delay the hydration of calcium aluminate during hydration of fast cement, and to stably produce and maintain ethrinite, SO ₄ ^{2 -} must be continuously supplied in aqueous solution.

For this purpose, when a mixture of high solubility gypsum and low solubility gypsum is appropriately mixed, SO ₄ ^{2 -} is continuously supplied from gypsum with different solubility even in the early stage of hydration reaction of the fast-hardening cement and later after the reaction. Condensation prevention, rapid strength expression, and continuous strength increase effect can be achieved simultaneously.

In other words, SO ₄ ^{2 -} ions eluted from _semi- hydrated gypsum react with calcium aluminate, which is rapidly hydrated at the beginning of contact with water, to produce crystalline ethrinzite on the surface of calcium aluminate hydrate. Prevents rapid hydration reaction by preventing contact with water to delay the reaction rate to secure pot life.

Subsequently, when SO ₄ ^{2 -} eluted from low solubility anhydrous gypsum is continuously supplied, the crystal form of etrinzite grows in a columnar needle shape, destroying the hydrate film surrounding calcium aluminate and contacting with water. Again causes vigorous ethrinzite production.

In the case of the present invention, when using gypsum mixed with anhydrous gypsum and hemihydrate gypsum, it is preferable that the content ratio of anhydrous gypsum and hemihydrate gypsum is mixed with 10-45 wt% of hemihydrate gypsum with respect to 100% by weight of anhydrous gypsum.

When the hemihydrate gypsum is less than 10% by weight, the effect of using the hemihydrate gypsum is small in the initial reaction with water.When the hemihydrate gypsum is more than 45% by weight, the solubility of the hemihydrate gypsum is high. This is because adverse effects such as deterioration of workability and heat generation during the reaction are exhibited.

There are three types of hemihydrate gypsum, α-type, β-type alone, or a mixture of both. In the present invention, any of them may be used, and both exhibit similar performance.

In the present invention, when the gypsum powder mixed with anhydrous gypsum and hemihydrate gypsum is 15 wt% or less with respect to 40 to 60 wt% of the Awin-based clinker, the amount of ethrinite is low, and absolute SO ₄ ^{2 -} ion is insufficient for the reaction. The resulting ethrinzite is decomposed into monosulfate, resulting in low expression.

If more than 30% by weight is added, the excessive gypsum content causes recrystallization of the hydrated gypsum and the relatively small ANN-based component, which causes the strength to be delayed.

The powder of the mixed gypsum used in the present invention is most preferably used in the 7,000 ~ 9,000 cm ² / g in terms of reaction rate control.

To the present invention, long-term eth- Lin ZUID generated and maintained to promote long-term strength increase over the normal hydration of the supply and the cement of calcium (Ca ^{2 +)} required for the process components, usually O wingye clinker of Portland cement 40-60% by weight 20 to 40% by weight is used.

C ₃ S (3CaO · SiO ₂ ) and C ₂ S (2CaO · SiO ₂ ), which usually make up a large portion of portland cement, contribute to the formation of ethrinzite and also provide long-term durability of CSH (CaOCaO · SiO). ₂ nH ₂ O) hydrate is formed to increase the stability.

In general, when the amount of Portland cement used is 40% by weight or less, the long-term stability of the cured product is lowered, and when 60% by weight or more is used, the absolute amount of the Arwin-based clinker component expressing the fastness is insufficient, thereby decreasing the fastness.

In the present invention, increase in the crystallinity of the initial reaction eth- Lin Xi bit and uses the calcium hydroxide (Ca (OH) ₂₎ for the purpose of supplying extra calcium (Ca ^{2 +).}

Ethrinzide hydrate, which determines the initial strength of fast cement, has large water expansion due to 32 water molecules during the formation process. Separated by.

In terms of initial strength development of fast-hardening cements, needles with large crystal phases are preferred, and the short monoliths have lower strength developments than needles and act as a cause of overexpansion in the long term.

In the early stage of the reaction, the decomposition of calcium (Ca ^{2 +} ) in the gypsum during the dissolution of hemihydrate gypsum increases, resulting in reduced ethrinite crystallinity. It is responsible for generating the net.

When the slaked lime is more than 4% by weight, the reaction rate in the composition system is accelerated, resulting in poor workability, and adversely affects strength.

In addition to the above-mentioned mixed composition consisting of the above-mentioned clinker and gypsum mixture, usually Portland cement and calcination circuit, it is more preferable to use a coagulation delay agent for smoothly controlling the pot life according to the use temperature conditions.

Retardants that delay the condensation by inhibiting the hydration of cement are classified into organic and inorganic type. The organic type is gluconate, lignin sulfonate, acetic acid, tartaric acid, citric acid, and polyol polymer complex. Are fluorine compounds, phosphates and silicon-based compounds.

In addition, sugars, such as glucose has a condensation delay effect.

The organic type includes one or several complexes of carboxyl group (-COOH), hydroxyl group (-OH), carbonyl group (-CO), etc. in the molecule, and the more complex these derivatives, the higher the coagulation delay effect. Examples are tartaric acid and citric acid.

The cement when in contact with the water-cement components are dissolved to reach the highest concentration of Ca ^{2 +} ions during the generation of a back hydration products saturated or supersaturated, through I, wherein receiving the hydration process, and the precipitated liquid to the water do.

Retardant acts to inhibit the amount of time that the concentration of Ca ^{2 +} ion reached the peak time, and to generate an insoluble metal complex salt so that the concentration is lowered to delay hydration.

In particular, molecules having a long hydrophobic group, such as a polymer carboxyl group or a carbonyl group, are adsorbed on the surface of the cement hydrate to form a multi-layered adsorption membrane, thereby delaying hydration.

As the retarder used in the present invention, tartaric acid, citric acid and sodium gluconate, which are organic retardants, may be used alone, or two or more thereof may be mixed.

Cemented carbide cement components, which are mainly composed of Irwin-based clinker, show a large difference in hydration reaction rate depending on temperature.

Therefore, in the summer when the temperature is high, the hydration of the cement components is also faster, so the amount of the retardant is increased, and on the contrary, the amount of the retardant is reduced in the winter when the temperature is low.

If the amount of retardant is increased, workability is increased and pot life is long, but it is better to minimize the amount of use as much as possible to reduce the initial strength.

The amount of coagulation delay was 0.2 ~ 1.0% by weight based on 100% by weight of the composition consisting of Irwin-based clinker and gypsum mixture, usually Portland cement and slaked circuit.

In addition, it is preferable to use a curing accelerator to accelerate the hydration of mineral components such as C ₃ S, C ₂ S in cemented carbide.

Inorganic metal salts are widely used as curing accelerators, and chlorine compounds, sulfuric acid compounds, acetates, and lithium salts are typical.

The curing accelerator promotes C ₃ S hydration to increase the calcium saturation (Ca (OH) ₂ ) supersaturation in the aqueous phase and increases the initial strength due to the active precipitation of the (CSH) hydrates called cement gels.

In the present invention, lithium carbonate or sodium sulfate may be used as a curing accelerator, and the amount thereof is appropriately used in an amount of 0.6 to 1.5% by weight based on 100% by weight of the mixed composition consisting of an Arwin-based clinker and a gypsum mixture, usually Portland cement and a slaked circuit.

In the composition of the present invention, it is more preferable to include a high fluidizing agent for improving the workability of concrete, watertightness through reduction of water-cement ratio, and the like.

Naphthalene sulfonic acid high condensate, melanin sulfonic acid formaldehyde high condensate, polycarboxylic acid polymer, and the like may be used as the high fluidizing agent.

The amount of the high fluidizing agent is 0.3 to 1.0% by weight based on 100% by weight of the mixed composition consisting of Irwin-based clinker and gypsum mixture, usually Portland cement and calcined circuit.

If it is more than 1.0% by weight, the slump is high and the fluidity is increased, which makes it difficult to finish the flat surface during construction and increases the bleeding due to the material separation, whereas the water-cement ratio reduction effect is less than 0.3% by weight.

In the present invention, it is preferable to use a small amount of antifoaming agent in order to reduce the air bubbles generated by the use of the polymer latex, and to maintain the amount of entrained air of the concrete at a level of 3 to 5%.

Defoamers used include silicones, alcohols, nonionics, fatty acids, phosphate ethers and the like.

There is no need to specifically limit the amount of antifoaming agent, but 0.1 ~ 0.5% by weight was found to be appropriate for 100% by weight of the mixed composition consisting of Arwin-based clinker and gypsum mixture, usually Portland cement and slaked lime.

If less than 0.1% by weight, the effect of the antifoaming agent appears small, and when used in excess of 0.5% by weight the amount of entrained air is greatly reduced workability and resistance to freeze-thawing is also reduced.

In the method of manufacturing cemented carbide concrete according to the present invention, a polymer modified cemented carbide concrete is prepared by mixing a suitable amount of water, fine aggregate and coarse aggregate, and polymer latex into the cemented carbide cement composition, and mixing it in a forced concrete pan mixer. It is characterized by preparing a composition.

At this time, the mixing amount of the material used depends on the maximum size of the coarse aggregate used.

 The polymer modified cemented carbide concrete of the present invention used in concrete pavement or slab emergency repair construction of bridges uses a larger maximum size of coarse aggregate as the construction thickness for overlaying or repairing is larger, and the maximum when the construction thickness is small. It is better to use coarse aggregates of smaller size, and accordingly, the mixing ratio of polymer modified cemented carbide concrete should be adjusted differently.

The larger coarse aggregates used generally have the same design strength as concrete mixes, resulting in lower unit binder usage and water-cement ratios, less dry shrinkage, and a tighter hardened body than the smaller aggregates. As a result, the high quality and economical concrete can be obtained.

Therefore, in the present invention, when the minimum depth of the cross section to be repaired is 50 mm or less, the maximum size of the coarse aggregate is set to 13 mm or less in consideration of the surface finish, and if more than 20 mm is presented.

This is because concrete with small size coarse aggregate of 13mm or less has a high risk of cracking when the depth of repaired section is large.

When the minimum depth of the cross section to be repaired is 50 mm or less, 168 to 200% by weight of the coarse aggregate having a maximum dimension of 13 mm to 100% by weight of the cemented carbide cement composition; Fine aggregate 230-265% by weight; 17-23 weight% of water; It is preferable to mix; SBR latex 26-36% by weight.

When the minimum depth of the cross section to be repaired is 50 mm or more, 195 to 230% by weight of the coarse aggregate having a maximum dimension of 20 mm to 100% by weight of the cemented carbide cement composition; Fine aggregate 234 ~ 270 wt%; 15-20% by weight of water; SBR latex 24 ~ 34% by weight; is preferably mixed.

The mixing order of these materials is as follows.

Firstly, the amount of water and polymer latex weighed for mixing one batch of superhard polymer concrete is premixed in a dedicated mixing bath.

Secondly, the coarse aggregate weighed into the forced concrete mixer is added, and then cemented carbide and fine aggregate are added in this order, and then mixed with premixed water while rubbing dry, and then mixed for 60 to 90 seconds. .

As the size of coarse aggregate increases from 13mm to 20mm, the volume of aggregate part that occupies concrete volume per 1m ³ increases and the amount of cement and water used decreases relatively. It is reduced, the drying shrinkage is also small, there is an effect of obtaining a good quality and economical composition.

In addition, when mixing water, water and polymer latex are not separately weighed and introduced into the blender, but pre-mixed water and polymer latex for one batch is premixed in a separate mixing tank before being mixed into the blender. There is an advantage that can be smooth and efficient.

Since polymer latex has a viscosity of 40-100 mPa.s higher than water and a surface tension of 25-50 dynes / cm, wetting with cement is lower than that of water, and a lot of bubbles are generated when stirring.

Therefore, if the concrete agitation time is short or there is not enough bibeam, there is a high risk of dispersing evenly and not evenly mixed with cement, and the quality of superhard concrete is increased by white bleeding on the surface after the manufacture or by a large amount of air bubbles. It can be a depressing factor.

Therefore, when the water and the polymer latex is added to the mixer in the pre-mixed water state as in the present invention, wetting with cement is improved and latex dispersibility is improved, and air bubbles are removed due to the reduction of air bubbles. There is no need for additional antifoaming agents.

In addition, the normal hydration reaction between the cemented carbide component and the latex-mixed water makes it possible to sufficiently exhibit the additive effect of the polymer latex.

In the present invention, the latex used for producing polymer modified cemented carbide concrete has a solid content of 44 to 47%, surface tension of 32 to 38 dyne / cm, viscosity (Brookfield viscosity) of 50 to 80 mPa · s, particle size of 130 to 180 nm, pH It is preferable to use SBR (Styrene-Butadiene-Rubber) latex having the characteristics of 9.0 to 10.5.

The amount of SBR-based polymer latex incorporation is preferably 11 to 17% by weight (24 to 36% by weight based on latex) based on 100% by weight of cemented carbide used on a solid content basis.

When the polymer latex is added in an amount of 17 wt% or more, the effects of adhesion, flame resistance, and water resistance are small due to the increase in the amount used, and the strength of 21 MPa or more in 3 to 4 hours due to the hydration of the cemented carbide component due to the excessive coating of the polymer Expression slows down.

If the amount of polymer latex is less than 11% by weight, the initial strength expression is improved, but there is a disadvantage that the effects of waterproofness, adhesion, flame resistance, etc. are reduced.

Hereinafter, an experimental example for examining the effects of the present invention will be described.

Table 1 shows the cement types used in polymer modified cemented carbide concrete, and Table 2 shows the concrete mix ratio.

The cemented carbide cement A of Comparative Example 1-1 is an Arwin-based cemented carbide cement, which is conventionally used like latex, and the cemented carbide cement B of Comparative Example 1-2 is a general cemented carbide cement using water alone.

The slump was measured according to KS F 2402, and the slump test was carried out separately after the discharge and 30 minutes after the discharge.

Concrete air volume was tested according to KS F 2421, hourly compressive strength was tested according to Korean Industrial Standard KS F 2405, and flexural strength was tested according to KS F 2408 respectively.

At this time, the method of using the polymer latex was uniformly applied to the method of pre-mixing water and latex, as in the present invention, in order to evaluate only the effect of the properties of the cement used.

Table 3 shows the physical property test results of the concrete produced by the combination of the above Examples and Comparative Examples.

As a result of the test, the concrete composition using cemented carbide as shown in the present invention was found to be excellent in all aspects, such as workability, compressive strength and flexural strength.

As in Comparative Example 1-1, when using the cemented carbide cement (A) used with the existing latex, the pot life is shorter than the present invention, the strength is slower than the present invention, Comparative Example 1 using only water and cemented carbide cement without latex -2 did not show the required strength even within 4 hours because the hydration of cemented carbide was slower when mixing latex.

Table 4 shows the variation of the aggregate aggregate ratio (s / A) of the mixing ratio up and down based on the composition ratio of the present invention according to the coarse aggregate maximum dimensions to be used, Table 5 is to evaluate the properties of the cemented carbide according to the .

Chlorine ion penetration resistance was tested according to KS F 2711, respectively.

In addition, the initial crack initiation time and crack width of the concrete were evaluated by the O-RING test method of ASTM A 501, which is a method of cracking test, and the waterproof performance of the concrete was performed according to KS F 4926.

As shown in Table 4, when the maximum coarse aggregate size is increased, it can be seen that the unit quantity is reduced in the overall composition by decreasing the water-cement ratio and decreasing the fine aggregate ratio.

Reduction of the unit quantity has the effect of reducing the unit cement amount if the same water-cement.

Accordingly, as shown in Table 4, the maximum amount of coarse aggregates is reduced in the amount of cement or unit water than when the condition of 20mm is 13m, the aggregate aggregate rate is also lowered.

Test results As shown in Table 5, the cemented carbide concrete composition ratio according to the present invention is preferably to vary the optimal mixing conditions of the aggregate and cement, water, etc. according to the maximum size of the coarse aggregate.

If there is too much fine aggregate (Comparative Example 2-2,2-3,3-2,3-3), there are problems such as deterioration of workability, deterioration of strength due to increase of air volume, cracking caused by a large amount of sand, etc. When the amount of aggregate is used too much, there is no big difference in terms of strength or dry shrinkage cracking, but there is a disadvantage that the surface finish is poor due to the roughness of the concrete.

Penetration resistance (chlorine ion permeability), especially for salinity, is generally very high when its value is over 4,000 coulombs, and is poor.It is moderate in the range of 4,000 to 2,000 coulombs and low in the range of 2,000 to 1,000 coulombs. In the case of 1,000 to 100 coulombs, it is considered to be a very low level and 100 coulombs or less.

In the concrete composition ratio of the present invention, the penetration resistance against salinity was 700 to 800 coulombs, which showed the best flame resistance.

Table 6 shows the conditions for preparing the polymer modified cemented carbide concrete, and the conditions for comparing the characteristics of the method of preparing water and latex, respectively, and the method of premixing water and latex before the injection as in the present invention. will be.

Mixing time (mixing time) was set to three 20 seconds, 40 seconds, 60 seconds and the same concrete formulation used in Example 3-1 of Table 4.

The test results are shown in Table 7.

The measurement of the amount of bleeding was performed based on F2414.

Looking at the results of Table 7, when weighing latex and water as in the present invention and premixed prior to the injection, when used for the production of cemented carbide concrete, the workability is improved compared to the conditions for the injection, and the mechanical properties are reduced due to insufficient mixing. And bleeding of unmixed latex appeared to be small.

If water and latex are added separately without premixing, if the boiling time is short, the bleeding results in poor workability and unmixed formula water as the mixing water is not wetted to the cement as in Comparative Example 4-1. This happens.

In addition, strength and durability are also poor.

Generally, latex modified cemented carbide concrete has a short boiling time of 5 to 10 seconds due to the characteristics of the mobile car manufactured in the field.

Therefore, when the blended water (water + latex) is premixed as in the present invention to produce polymer modified superhard concrete, the wetting performance is improved, and the mixing with the blended water occurs well even in a short stirring time.

Since the above has been described only with respect to some of the preferred embodiments that can be implemented by the present invention, the scope of the present invention, as is well known, should not be construed as limited to the above embodiments, the present invention described above It will be said that both the technical idea and the technical idea which together with the base are included in the scope of the present invention.

Claims (14)

delete A dry blending step of mixing the cemented carbide composition and aggregate; A premixing step of preparing a blended water by mixing water and a polymer modifier; And a concrete manufacturing step of mixing the blended water in the mixture of the cemented carbide cement composition and aggregate. The cemented carbide cement composition is 40 to 60% by weight of a powder obtained by pulverizing an Arwin-based clinker containing 60 to 85% by weight of calcium sulfo aluminate (3CaO.3Al ₂ O ₃ .CaSO ₄ ); 15 to 30% by weight of gypsum powder mixed with anhydrous gypsum and hemihydrate gypsum; Usually 20-40% by weight of Portland cement; Slaked lime 1 to 4% by weight; Method for producing a polymer modified cemented carbide concrete composition comprising a. The method of claim 2, The powder obtained by pulverizing the Irwin-based clinker has a specific surface area of 6,000 ~ 9,000cm ² / g by the method of producing a polymer modified superhard concrete composition. The method of claim 2, The gypsum powder is a method for producing a polymer modified cemented carbide concrete composition, characterized in that 10 to 45% by weight of the hemihydrate gypsum is mixed with respect to 100% by weight of the anhydrous gypsum. The method of claim 2, The gypsum powder has a specific surface area of 7,000 ~ 9,000 cm ² / g by the method of producing a polymer modified superhard concrete composition. The method of claim 2, The method of producing a polymer-modified cemented carbide concrete composition, characterized in that 0.3 to 1.0 wt% of the high fluidizing agent is further mixed with respect to 100 wt% of the cemented carbide cement composition. The method of claim 2, The method of producing a polymer-modified superhard concrete composition, characterized in that 0.2 to 1.0% by weight of the coagulation delay agent is further mixed with respect to 100 wt% of the superhard cement composition. The method of claim 2, The method of producing a polymer-modified cemented carbide concrete composition, characterized in that the mixing accelerator 0.6 ~ 1.5 wt% with respect to 100 wt% of the cemented carbide cement composition. The method of claim 2, A method for producing a polymer-modified cemented carbide concrete composition, characterized in that 0.1 to 0.5 wt% of the antifoaming agent is further mixed with respect to 100 wt% of the cemented carbide cement composition. The method of claim 2, Wherein said polymer modifier comprises SBR latex. The method of claim 10, The amount of the SBR latex incorporation is based on solids, based on 100% by weight of the cemented carbide cement composition, the method of producing a polymer-modified cemented carbide concrete composition, characterized in that 11 to 17% by weight. The method of claim 10, If the minimum depth of the section to be repaired is 50 mm or less, For 100% by weight of the cemented carbide cement composition, 168 ~ 200% by weight of the coarse aggregate is the largest dimension of the aggregate; Fine aggregate 230 ~ 265% by weight of the aggregate; 17 to 23% by weight of the water; 26 to 36% by weight of the SBR latex; Method for producing a polymer modified cemented carbide concrete composition, characterized in that mixing. The method of claim 10, If the minimum depth of the section to be repaired is 50 mm or more, For 100% by weight of the cemented carbide cement composition, 195 ~ 230% by weight of the coarse aggregate is the largest dimension of the aggregate; Fine aggregate 234 ~ 270% by weight of the aggregate; 15 to 20% by weight of the water; 24 to 34% by weight of the SBR latex; Method for producing a polymer modified cemented carbide concrete composition, characterized in that mixing. The method of claim 10, The dry blending step is made by injecting coarse aggregate, the cemented carbide cement composition, fine aggregate in the order of forced pan mixer and dry kneading, The concrete manufacturing step is a method for producing a polymer modified superhard concrete composition, characterized in that by adding the blended water to the dry blended mixture is performed for 60 to 90 seconds.