KR100548172B1 - A multi-functional admixture for a concrete structure - Google Patents

Abstract

The present invention relates to a multifunctional admixture used in mixing with concrete, and more specifically, to improve the physical properties and quality of concrete by simultaneously giving sensitivity, fluidity, water resistance and chemical resistance when placing concrete for construction of civil structures and building structures. A multifunctional admixture capable of achieving the same, which is 40 to 65% by weight of dispersant, 5 to 20% by weight of fatty acid salt, 15 to 35% by weight of silica, 5 to 10% by weight of accelerator, 1 to 5% by weight of plasticizer and interface It contains 0.2 to 1% by weight of the active agent, and when the concrete is poured in small amounts of the admixture can be obtained such as quality improvement effect, such as improving the durability of concrete and waterproof, chemical resistance.

Concrete, Admixture, Waterproof, Dispersant

Description

A multi-functional admixture for a concrete structure

The present invention relates to a multifunctional admixture used in mixing with concrete, and more specifically, to improve the physical properties and quality of concrete by simultaneously giving sensitivity, fluidity, water resistance and chemical resistance when placing concrete for construction of civil structures and building structures. It relates to a multifunctional admixture that can achieve.

In general, concrete is a mixture of cement and water in a certain amount of sand and gravel, stirred, and then poured to form a structure such as a building. The concrete structure is dried and hardened to maintain a certain strength, but moisture in the rainwater or air leaks into the numerous voids formed by the gravel and sand constituting the concrete, and not only weakens the strength of the concrete itself, but also the temperature. Due to the change of the volume of water in the air gap due to the cracking of the structure, cavitation and the outflow of slaked lime generated during hardening shrinkage, such as mold and bleaching of the inner wall occurs, there is a problem that the life is shortened and hurt the aesthetics. In addition, as time goes by, corrosion occurs in the steel reinforcing bars included in the concrete, thereby causing a problem in that the concrete is separated from the reinforcing bars.

In order to solve this problem, in recent years, there is a case in which a waterproof effect is obtained by densifying concrete structure or applying a separate waterproofing agent to a civil construction or building structure requiring waterproofing. For example, in the case of the inorganic spray penetrating waterproofing agent, an insoluble crystal formed by reacting the cement component in the concrete structure with soluble calcium hydroxide and the waterproofing agent component penetrated after application by applying the inorganic powder to the structure after concrete pouring fills the voids in the structure. One way is waterproofing. However, this method alone is not only enough to achieve the waterproof effect of concrete, but additional measures to infiltrate a large number of additives such as surface treatment or penetrant as a measure to compensate for the insufficient functions and properties after concrete construction are inevitable. In addition to being the main cause, there is a problem that can act as a cause of concrete deterioration due to the compositional imbalance with such additives. In order to solve this problem, in recent years, a mixture of a reducing agent, a fluidizing agent and other compounding agents are collectively administered at a time, but these are also manufactured without a clear standard of composition ratio between the compoundings. Offsets may not meet certain objectives or may cause unexpected concrete deterioration of properties.

Accordingly, the present invention, in consideration of the above problems, to solve the above problems that may occur when each of the additives to the concrete or when the batch is administered at the same time to further improve the quality of the concrete, fatty acid salts, dispersants, By providing surfactants, silica, accelerators, and plasticizers in a specific ratio, the effect of each component is not canceled to provide a multifunctional admixture for concrete structures that can effectively provide sensitivity, fluidity, water resistance, rust resistance and chemical resistance. .

The composition of the present invention for exhibiting multifunctionality with one mixing agent is 40 to 65% by weight, 5 to 20% by weight fatty acid salt, 15 to 35% by weight silica, 5 to 10% by weight accelerator, 1 to 5% by weight plasticizer % And 0.2 to 1% by weight of surfactant. The compositions have important meanings in proportions that can achieve the optimum effect without counteracting the effect of each component.

The dispersant used in the present invention is a surfactant component in which the molecules adsorbed on the cement particles act on the principle of dispersing the cement particles by electrostatically acting on the cement particles, and have the characteristics of bubbles, wetting, dispersion, emulsification and solubilization. It contributes to the improvement of cement particle dispersion, fluidity, uniform cement hydration and workability in concrete. It can be arbitrarily selected from known dispersants, and generally includes hydrophilic groups such as sulfonic acid group (-SO ₃ ), carboxyl group (-COO), and hydroxyl group (-OH), and typical examples thereof include lignin and naphthalene ( naphthalene), melamine or polycarboxylic acids. Specifically, lignin sulfonates, polycarbonates, oxycarbonates, polyol derivatives, polyoxyethylene alkylallyl ether derivatives, alkyl allyl sulfonic acid formalin condensates, melamine sulfonate formalin condensates, polycarboxylic acid polymer compounds, such as lignin Calcium sulfonate, sodium lignin sulfonate, sodium naphthalene sulfonate formalin condensate, polycarboxylic acid copolymer or melamine sulfonate sodium formalin condensate. In the case of using these dispersants, not only can the water content be reduced by 20 ~ 30% in concrete manufacturing, but also the working efficiency can be increased by increasing the fluidity of the concrete, and the strength of the cured concrete can be increased to the granite level. It can also be suitably used for special structures requiring strength such as bridges or bridges. The composition ratio of the dispersant in the present invention is 40 to 65% by weight. This is a ratio determined according to the composition ratio of fatty acid salts, etc., which will be described below, and is a residual ratio excluding the composition limit ratio of the other components based on 100 wt%.

Next, the fatty acid salt used in the present invention may be selected from any one of fatty acid metal salts or fatty acid esters, but in the case of fatty acid esters, the fatty acid metal salts may act as a factor in impairing the cement hydration reaction or degrading adhesion. This is more preferably used. As the fatty acid metal salt, higher fatty acid salts such as zinc oleate, calcium oleate, aluminum oleate, zinc stearate, calcium stearate or magnesium stearate are preferable. Fatty metal salts or fatty acid esters can be administered into concrete by either direct injection into cement mortar or concrete to remain in the voids, and into the concrete to react with the metal in the cement to convert to insoluble fatty acid metal salts. You can also use. In the present invention, the fatty acid is mixed at about 5 to 20% by weight of the total weight of the admixture. This is because the fatty acid should contain at least 5% by weight in order to exhibit the waterproof effect, but if the content exceeds 20% by weight, there is a disadvantage that can weaken the strength of the concrete. In particular, it is more preferable to contain 10 to 15% by weight in order to obtain the optimum waterproofing effect and the optimum strength within the above range. In addition, in the case of fatty acid metal salts, it is preferable to select a powder type having a particle diameter of 5 μm or less because the smaller the particle size is, the greater the effect exerted.

Silica, which is another component of the present invention, reacts with calcium hydroxide during cement hydration to be converted to calcium silicate to form a fine concrete structure. In order to work more effectively, it is preferable to use amorphous amorphous or ultrafine silica. . By mixing the silica with the admixture, the reduction of shrinkage expansion due to temperature change, the binding force between the aggregates, the cohesion force and the adhesive force are improved, and the effects of inhibiting alkali aggregate reaction, improving water resistance, resistance to chloride and enhancing strength are also exerted. In addition, by reducing the water content in the air gap by minimizing the action of interparticles to reduce the flow and workability is also improved. The silica used in the present invention may be selected from fume silica, silica sol, silica colloid, silica slurry or zeolite silica, and these main components are all SiO ₂ to react with Ca (OH) ₂, which is a cement component, to form CSH bonds. do. Such a large amount of calcium silicate CSH gel is densely packed in the pores of concrete to enhance the waterproofing and chemical resistance to exert the effect of inhibiting the penetration of chloride to have excellent corrosion resistance to the iron structure. Particularly, among them, fume silica has a SiO ₂ content of 90 to 96% and a fine powder with a particle size of about 0.1 to 0.15 μm, which is effective because it can form ultra fine powders equivalent to tobacco smoke. The more the silica component is contained in the mixture for the concrete structure, the compressive strength of the concrete is increased, but if it is excessively added, there is a problem in that the viscosity is increased. Therefore, it should be used within the range of 10 to 25% of the total weight of the admixture. do. It is preferable to add in 15 to 20weight% in this range, in order to show the optimal strength and viscosity.

Accelerators are added to control the rate of hardening of concrete, which shortens the congealing time of concrete due to temperature changes and prevents collapse. As the accelerator in the present invention, for example, inorganic salts such as calcium chloride, sodium chloride, carbonate or triethanolamine salt, calcium silicate and the like can be used. The content of the accelerator in the admixture of the present invention is to be contained in 5 to 10% by weight in consideration of the concrete setting time and the ratio with other components.

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Plasticizer is a material mixed in small amounts to increase the activity of concrete, so that sodium gluconate is used in the present invention. This not only serves to reduce the dryness of the concrete surface, to maintain moisture retention and to delay the cement condensation, and also to prevent the microcracks by inhibiting the plastic condensation of the concrete. In addition, it forms a complex with alkaline earth metals Ca ²⁺ , Mg ²⁺ and Al ³⁺ to dissolve or disperse metal salts, thereby increasing the hydration rate and inhibiting cracking or shrinkage by susceptibility, bleeding, and exothermic action. The effect of increasing plasticity is also exhibited. However, if it is excessively added, it may affect the setting time of the composition, so it should be used within a maximum of 5% by weight.

In the present invention, the surfactant plays a role in helping components that are not well mixed with water, such as fatty acid salts, to be well dissolved in water. It is used as a component to assist the dissolving power as described above in a very small amount, preferably less than 1%.

The admixture of the present invention prepared by mixing the above components is preferably sprayed using a high pressure disperser. In this case, since the particles of the composition are dispersed at a high pressure in a very fine state, it is possible to prevent the composition from being sprayed in a less mixed agglomerate state and to further increase adhesion and density with the structure. However, at this time, since the bonding structure of the composition polymers may be broken when the pressure is too strong, the injection pressure is preferably in the range of about 250 to 300 bar.

The admixture for concrete structures thus prepared exhibits susceptibility and fluidity by dispersants and promotes pozzolanic hydration of silica by such a cement dispersing force to form gel silicate calcium silicate. It is distributed, so that the waterproof effect and chemical resistance are significantly improved, and the penetration inhibitory effect of chloride is exerted. In addition, the fatty acid metal salt is uniformly filled in the pores of the hydration reactant to maintain the high strength of the concrete due to excellent water resistance and dense pore formation, and does not corrode easily by being eroded by acid and alkali. In particular, it is possible to exhibit a multi-function as described above, by limiting the composition ratio of each component of the admixture of the present invention to a specific ratio, the effect of each component is not canceled, but the effectiveness of each component can be exerted, but the physical properties of the concrete This is because the composition ratio was limited so as not to adversely affect the composition. The composition ratio is specific to the composition ratio that can exhibit the optimum effect through various experiments carried out by the inventors, the effect can be confirmed in the following examples. In addition, the admixture does not contain chloride and does not cause environmental pollution, and even when the admixture is used in an excessive amount by limiting the composition ratio of each component that may cause the deterioration of the physical properties of the admixture, there is an advantage that does not cause the deterioration of the properties of the concrete. .

Hereinafter, the present invention will be described in more detail. However, this is for the purpose of helping the understanding of the present invention, and the scope of the present invention is not limited thereto.

Example 1

40 to 65% by weight of the total composition of any one or two of lignin sulfonate or naphthalene sulfonate formalin condensate, polycarboxylic acid copolymer, melamine sulfonate formalin condensate as a dispersant Then, 0.3 to 1% by weight of 8 to 20 mol of nonylphenol is added as a surfactant, followed by stirring at about 60 to 80 ° C for 30 minutes. As the higher fatty acid metal salt, any one or two of calcium stearate, zinc stearate, magnesium stearate, calcium oleate, zinc oleate, and aluminum oleate is mixed, and 5 to 15% by weight is added, followed by stirring at 400 to 600 RPM for 40 to 60 minutes. Here, since the particles of the stearic acid metal salt exhibit fine waterproofing effect as fine as possible, the particles of the stearic acid metal salt are preferably micronized to 5 탆 or less. 15 to 35% by weight of silica sol, silica slurry or silica fume is added thereto, and the mixture is stirred at 50 to 80 minutes while decelerating to 250 to 400 RPM while maintaining the temperature at 40 to 60 ° C. 1 to 5% by weight of sodium gluconate in an aqueous solution of 10 to 30% by weight as a plasticizer and 5 to 10% by weight of triethanolamine as an accelerator are added to the mixture and stirred at constant speed for 40 to 60 minutes. Thereafter, the mixture is left at 40 to 60 ° C. for 3 hours and then sprayed at a pressure of 250 to 300 bar using a high pressure disperser.

Example 2

In the following, tests were conducted to confirm the effects of compressive strength, permeability ratio, flexural strength and the like when using the mixture of the present invention in concrete.

[Example 1]

0.6 mol% of 10 mole of nonylphenol was added to 60 wt% of a mixture of a naphthalene sulfonic acid formaldehyde condensate, an aqueous solution having a 40% active ingredient and a 40% active ingredient as a polycarboxylic acid, and 0.6% by weight of 10 mol of nonylphenol. Raise and stir for 30 minutes. After stirring 6 weight% of calcium oleate at 400 RPM for 60 minutes, liquid temperature was lowered to 60 degreeC, 18 weight% of silica sol of 30% of solid content of 20-50 nm of particle diameter was added, and it stirred for 40 minutes. Then, a mixture of 3.4% by weight of sodium gluconate, 3% by weight of triethanolamine, and 8% by weight of water was added to the mixture by stirring for 30 minutes, stirred at constant speed for 40 minutes, and aged for 5 hours while maintaining the liquid temperature at 40 ° C. Let's do it. This is dispersed at a pressure of 300 bar using a high pressure disperser.

[Example 2]

Melaminesulfonic acid formalin condensate 38% aqueous solution and 40% polycarbonate sodium soda was added to 55.5% by weight of the mixture at a mixing ratio of 3: 1, 10 moles of nonylphenyl 0.6% by weight was raised to 70 ° C, and stirred for 30 minutes. Add 8% by weight of calcium stearate and disperse for 30 minutes. Then, the solution temperature is lowered to 40 ° C. and 18% by weight of 30% silica sol having a particle diameter of 20 to 50 nm is added and stirred for 40 minutes. Next, 4.4% by weight of sodium gluconate, 3% by weight of triethanolamine, and 10% by weight of water are added to the mixture, followed by constant stirring for 40 minutes. This is dispersed at 250 bar pressure using a high pressure disperser.

Example 3

After heating 65% by weight of 40% polycarbonate sodium at 70 ° C, 0.5% by weight of 10 moles of nonylphenol, 5% by weight of gluconda, 9.5% by weight of triethanolamine and 10% by weight of water were added at 40 ° C. It stirred for 20 minutes, and stirred for 35 minutes. 10 wt% of calcium stearate was added thereto, dispersed for 50 minutes, and the liquid temperature was maintained at 40 ° C. This is dispersed at a pressure of 300 bar using a high pressure disperser.

Example 4

65% by weight of 38% melamine sulfonate formalin condensate is heated to 80 ° C, 0.6% by weight of 10 mol of nonylphenol is added thereto, and stirred for 20 minutes, followed by 4% by weight of triethanolamine, followed by stirring for 20 minutes. Then, 12% by weight of calcium stearate is added, the mixture is stirred for 40 minutes, and the liquid temperature is lowered to 40 ° C. 18 wt% of 30% silica sol having a particle diameter of 20 to 50 nm was added thereto, followed by stirring for 40 minutes. This is dispersed at a pressure of 300 bar using a high pressure disperser.

The admixtures of the present invention prepared in Examples 1 to 4 were mixed at a ratio of 1% by weight with respect to concrete to test compressive strength, permeability ratio, flexural strength, and the like. In the table below, the standard is the test result of the general concrete which does not blend the admixture of the present invention, and Examples 1 to 4 are the results measured by blending the admixture of the present invention prepared from Examples 1 to 4 above. As shown in the table below, the admixture of the present invention exhibits susceptibility and fluidity by the dispersant and promotes pozzolanic hydration of silica by such cement dispersing force to form gel calcium silicate, and the calcium silicate voids Evenly distributed in the inside, significantly increasing the waterproof effect. In addition, the fatty acid metal salt was uniformly filled in the pores of the hydration reactant to maintain the high strength of the concrete due to excellent water resistance and compact pore formation, it was confirmed that it is suitable as a physical property improving agent of the mold product by reducing the foaming rate. In particular, as shown in Tables 2 and 3, it was confirmed that the use of the admixture of the present invention was superior in slump, compressive strength, permeability ratio, flexural strength, etc. It was confirmed that the best functional effect.

division W / C (%) S / A (%) Coarse aggregate (mm) Formulation (kg / ㎥) W C S H SP Standard 37 68 25 180 485 676 992 - Yes 37 68 25 180 485 676 992 C x 1%

division Air volume (%) Slump (cm) Compressive strength (㎏ / ㎠) Pitching cost 3 days 7 days 28 days Standard 1.82 4.3 280 323 428 - Yes One 1.62 22 332 428 464 0.32 2 1.7 23.2 358 462 512 0.28 3 1.64 22.8 350 440 506 0.42 4 1.72 23 352 456 504 0.30

Unit Cement (㎏ / ㎥) Yes W / C S / A Slump (cm) Flexural strength (㎏ / ㎠) Added amount (C x 1%) 500 0 37 34 6.1 67.4 One 32.6 33.4 7.4 86.8 2 31.6 33.3 6.9 90.2 3 32.3 34.2 7.5 89.2 4 32 32.6 7.2 89.6

The present invention is a multifunctional admixture capable of performing a multifunction by combining the admixture functions of various components into one, limiting the composition ratio of each component of the admixture to a specific ratio so that the effect of each component does not cancel the effect of each component By limiting the composition ratio so that it can be exerted, it is possible to maintain high watertightness by simultaneously giving concrete properties improvement and susceptibility, fluidity, waterproofness and chemical resistance when concrete is used for civil structures and building structures. It is excellent in melting stability and pore filling, and it enhances the strength of concrete, prevents it from being eroded by acid and alkali, and makes material management and construction quality control easy and cost-effective. In particular, since the admixture does not contain chloride, it does not have any influence on the secondary process after environmental pollution or concrete pouring, and thus does not cause deterioration of properties of concrete even when excessively used.

Claims (9)

In the admixture for concrete structures, 40 to 65% by weight of dispersant, 5 to 20% by weight of fatty acid metal salt, 15 to 35% by weight of silica, 5 to 10% by weight of accelerator, 1 to 5% by weight of plasticizer and 0.2 to 1% by weight of surfactant Admixture for concrete structures comprising a. delete delete The admixture for concrete structures according to claim 1, wherein the fatty acid metal salt is at least one of zinc oleate, calcium oleate, aluminum oleate, zinc stearate, calcium stearate, and magnesium stearate. delete delete The method of claim 1, wherein the silica is fume silica or silica slurry having a particle size of 0.1 to 0.15㎛ m, or at least any one of silica sol, silica colloid and zeolite silica having a particle size of 20 to 50nm. Admixture for concrete structures, characterized in that. The admixture for concrete structures according to claim 1, wherein the admixture for concrete structures is dispersed at a pressure of 250 to 300 bar using a high pressure disperser. delete