KR100841067B1 - Liquid composition for water-proof in concrete - Google Patents

Abstract

A liquid spherical waterproofing material composition and a method for preparing the composition that have excellent waterproof performance and can reduce construction time and cost are presented. According to an aspect of the present invention, it provides a liquid sphere waterproofing material composition prepared by combining oleic acid, silica, ammonia water, a fluidizing agent and water.

Oleic acid, silica, concrete waterproofing

Description

Liquid composition for water-proof in concrete

The present invention relates to a liquid concrete waterproofing material composition used for concrete waterproofing, anticorrosion, flame resistance, neutralization prevention.

In general, concrete structures are known to have a service life of about 50 years, but due to deterioration due to physical and chemical environmental conditions, major repairs and reconstructions are inevitable, causing economic losses.

Waterproofing means blocking water from passing through or seeping through concrete structures. However, due to the deficiency of the waterproof performance of such concrete structures, in case of leakage, compressive strength, freeze-thawing resistance, resistance to chemical erosion, etc. are reduced, which shortens the life of the structure and damages the aesthetics of the building and serves as a living space. Habitability is also greatly reduced, resulting in economic losses.

As a waterproofing method to solve leaks, there are various methods depending on the materials used and construction methods. Recently, research on the development of concrete waterproofing methods is continuously conducted. The concrete waterproofing method is a method of waterproofing the whole structure by remarkably reducing the permeability and absorbency of the concrete itself, and by using concrete waterproofing material when manufacturing ready-mixed concrete or mortar, there is no need for additional waterproofing work. Not only is it economical, it also improves durability, corrosion resistance and heals defects.

Specifically, the concept of waterproofing, anticorrosion of concrete spheres is as follows.

Concrete is mixed with cement (Portland cement), aggregate and water to produce hydrates. The chemical equation is:

3CaOSiO ₂ (C ₃ S)

2CaOSiO ₂ (C ₂ S) CSH (CaO, SiO ₂ , NH ₂ O)

CaSO ₂ H ₂ O (gypsum) + H ₂ O → Ca (OH) ₂

3CaAl ₂ O (C ₃ A) 3CaOAl ₂ O ₃ CaSO ₄ 32H ₂ O

4CaOAl ₂ O ₃ Fe ₂ O ₃ (C ₄ AF) 3CaOAl ₂ O ₃ CaSO ₄ 12H ₂ O

Hydration products are largely composed of four types. CSH (CaO, SiO ₂ , NH ₂ O) is composed of dense or fibrous densities of 1 μm or less, and is the most stable structure among concrete components. 3CaOAl ₂ O ₃ CaSO ₄ 32H ₂ O and 3CaOAl ₂ O ₃ CaSO ₄ 12H ₂ O consist of a needle-like or hexagonal lamination structure of several μm or less, which expands greatly by taking the number of bonds of huge water molecules. This expansion causes concrete to deteriorate, crack, and even collapse. Ca (OH) ₂ is piled up in layers as a hexagonal plate of several tens of micrometers and remains. Neutralization, which is caused by reaction with carbon dioxide (CO ₂ ) in water or in the air, causes deterioration, and reacts with H ₂ SO ₄ to form 3CaOAl ₂ O ₃ CaSO ₄ 32H ₂ O, which expands greatly by taking the bound water. . In other words, calcium hydroxide provides a cause of cracking or greatly promotes the expansion of cracks, thereby playing a decisive role in strength degradation and tissue degradation. After all, it is a good way to remove the calcium hydroxide crystals in order to increase the strength of the hardened cement and to increase the durability by densifying the tissue.

Conventional powder concrete concrete waterproofing material is difficult to mix when mixed in concrete, there was a concern about environmental pollution due to the generation of scattering dust. In addition, it has been developed as a liquid sphere waterproofing material has a disadvantage that many unnecessary additives and the manufacturing method is complicated.

It is an object of the present invention to provide a liquid sphere waterproof composition and a method for producing the composition excellent waterproof performance and can save time and cost.

In order to achieve the above object,

According to an aspect of the present invention, a spherical waterproofing composition including 15 to 25% by weight of oleic acid, 1 to 10% by weight of silica, 1 to 5% by weight of ammonia, 1 to 5% by weight of a fluidizing agent, and water may be provided.

In the present invention, the oleic acid is included in 15 to 25% by weight of the total weight of the waterproofing material. This is because the oleic acid should contain at least 15% by weight of the total weight in order to exhibit a waterproof effect, but when the oleic acid exceeds 25% by weight there is a problem that can weaken the strength of the concrete.

When mixed with higher fatty acids in concrete, it combines with calcium hydroxide produced in the hydration reaction of cement to produce higher fatty acid calcium with water repellency. These higher fatty acid salts have excellent water repellency, which reduces water absorption by capillaries in concrete.

Silica, which is another component of the present invention, reacts with calcium hydroxide during cement hydration, and converts 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, reduction of shrinkage expansion due to temperature change, binding strength, cohesion and adhesion between aggregates is improved, and the effects of suppressing alkali aggregate reaction, improving water resistance, resistance to chloride and enhancing strength are also exerted. It also improves fluidity and workability by minimizing moisture in the pores by reducing water and reducing attraction between particles.

The silica used in the present invention may select one or more materials selected from the group consisting of fume silica, silica sol, silica colloid, silica slurry, zeolite silica and fly ash. Their main component is formed to both the calcium hydroxide Ca (OH) ₂ reacts with the calcium silicate _{CSH (CaO, SiO 2, NH} 2 O) combined with SiO _2. Such a large amount of calcium silicate CSH is densely packed in the pores of the concrete to improve the waterproofing effect and chemical resistance to exhibit the effect of inhibiting the penetration of chloride and excellent rust resistance to the iron structure. In particular, since fumed silica has a SiO ₂ content of 90 to 96% and its particle size is in the form of a fine powder of 0.1 to 0.15 μm, it is more effective because it can form an ultrafine powder as cigarette smoke. In addition, it is mixed into the mortar or concrete in the form of powder to fill the voids between the cement particles after hardening the concrete, and at the same time to fix the calcium hydroxide produced by the cement hydration reaction with the pozzolanic reaction to keep the mortar or concrete tight and crack. It also heals. The more the silica component is contained in the waterproofing material for the concrete structure, the compressive strength of the concrete is increased, but if it is added too much, there is a problem in that the viscosity is increased, so it is used within the range of 1 to 10% by weight of the total weight. desirable.

In addition, the spherical waterproofing material of the present invention preferably contains 1 to 5% by weight of ammonia, which forms a salt with oleic acid and contributes to the water repellency of the concrete sphere. In the present invention, ammonia water was used, but it is also possible to use calcium hydroxide or potassium hydroxide. When the ammonia water is added below 1% by weight, the oleic acid salt is not sufficiently formed, and when added above 5% by weight, there is a problem of odor due to excess ammonia.

The fluidizing agent improves the mortar or concrete's deterioration of fluidity when incorporating concrete waterproofing materials, thereby making compact compacted structures with little compaction when concrete is poured. A fluidizing agent mainly based on melamine-formaldehyde condensate is used, which is preferably included in an amount of 1 to 5% by weight of the total weight of the waterproofing material. When added to 1% by weight or less there is a problem that can not ensure sufficient fluidity of the waterproof material, when added to 5% by weight or more there is a problem that is difficult to harden and may cause a decrease in strength of the concrete.

Water may be added in an appropriate amount to match the contents of the components of the waterproofing material of the present invention. The present invention includes carrying out by modifying the numerical value of the components within the above weight% range, the range is the most appropriate in consideration of economics and effects of the invention.

In order to analyze the waterproof performance of the spherical waterproofing material of the present invention, the inventors prepared concrete and mortar in which the spherical waterproofing material of the present invention was mixed, and measured the compressive strength ratio, absorption ratio, permeability ratio, and flame resistance. As a result, when the concrete is manufactured using the concrete waterproofing material of the present invention, the waterproofing performance is improved, and in particular, when the 0.9 to 0.95% of the cement content is used, the performance is greatly improved (see Table 2). In addition, as shown in Table 3, when the concrete is manufactured using the concrete waterproofing material of the present invention, the strength of the concrete is greatly improved, and the compressive strength ratio of the concrete is increased by 15 to 20% with respect to the control group without the mixing of the concrete waterproofing material. Confirmed. In addition, as shown in Table 4, the composition of the present invention was shown to greatly inhibit the penetration of chloride ions.

In addition, the spherical waterproofing material of the present invention has the advantage of easy to mix concrete, less generation of dust, and simpler components than the conventional spherical waterproofing material can lower the production cost.

In addition, according to another aspect of the present invention,

i) adding water to the oleic acid and stirring;

ii) stirring the reaction product of step i) with silica and water for 30 minutes to 90 minutes;

iii) heating the reaction of step ii) to 50-60 ° C. and stirring;

iv) adding ammonia water and water to the reaction of step iii) and reacting for 3 to 5 hours;

v) adding a fluidizing agent to the reactants of step iv) can provide a process for the preparation of a liquid sphere waterproofing composition.

The oleic acid is preferably included in 15 to 25% by weight of the total weight of the waterproofing material. In a preferred embodiment of the present invention, 20 kg of oleic acid was added to 20 kg of water and stirred at a rotational speed of 120 rpm to emulsify for about 30 minutes.

Subsequently, silica and water are added to the emulsified reactant, followed by stirring. The silica may be at least one material selected from the group consisting of fume silica, silica sol, silica colloid, silica slurry, zeolite silica, and fly ash. . Preferred of the present invention In the example, 5 kg of silica fume and 10 kg of water were added to the emulsified reactant of step i) and reacted for 60 minutes. In the case of stirring for 30 minutes or less, the reaction may not proceed sufficiently, so that the yield may be a problem in a subsequent process, and in the case of stirring for 90 minutes or more, there is a problem of gelation of the reactants.

Subsequently, the reactants were slowly heated to maintain 50 to 60 ° C., sufficiently stirred at 70 to 150 rpm, and slowly added with ammonia water and water. In this step, oleic acid and ammonia water react to form an ammonium oleate salt. When reacting for 3 hours or less, an unpleasant odor unique to ammonia remains and a mild odor is generated around 4 hours. 5 hours or more is excessive time for the yield. The reactant is lowered to 30 ° C. or lower, followed by adding a fluidizing agent to prepare a composition of the present invention.

Hereinafter, the present invention will be described in detail by way of examples and test examples. However, this is only for the purpose of illustrating the present invention is not limited thereto.

Example 1 Preparation of Sphere Waterproofing Composition

20 kg of oleic acid was added to 20 kg of water, stirred at a rotational speed of 120 rpm, emulsified for about 30 minutes, and then 5 kg of silica fume and 10 kg of water were added to the emulsified reaction. After stirring for 60 minutes, the mixture was slowly heated to maintain the temperature at 50 to 60 ° C and stirred at 90 rpm. Here, 3 kg of ammonia water and 40 kg of water were slowly added over 1 hour and reacted for 4 hours. After lowering the reaction product to 30 ° C. or lower, 2 kg of a fluidizing agent was added and stirred. After about 1 hour a viscous off-white solution was obtained, which was packed in plastic containers of 18 kg each.

Test Example 1 Waterproofing Performance Analysis of Concrete Waterproofing Materials

<1-1> Preparation of Test Concrete

In order to analyze the waterproof performance of the concrete waterproofing material of the present invention prepared through Example 1, the concrete was mixed with the material as shown in Table 1 to prepare the concrete waterproofing material of the present invention.

Standard blending ratio (kg / m ³ ) division cement Fine aggregate Coarse aggregate water AE Concrete waterproofing Control 325 754 1.044 172 C x 0.5% - Trial Concrete 1 325 754 1.044 172 C x 0.5% C x 0.5% Test Concrete 2 325 754 1.044 172 C x 0.5% C x 0.7% Trial Concrete 3 325 754 1.044 172 C x 0.5% C x 0.8% Test Concrete 4 325 754 1.044 172 C x 0.5% C x 0.9% Test Concrete 5 325 754 1.044 172 C x 0.5% C x 0.95%

* C: cement content

<1-2> Absorption Ratio and Permeability Ratio Measurement

According to KS F 4926, the absorption ratio and water permeability ratio of the concrete mixed with the concrete waterproofing material of the present invention were obtained. The results are shown in Table 2.

(Test method: KS F 4926) division Absorption ratio Pitching cost Control 0.7 or less 0.7 or less Trial Concrete 1 0.45 0.46 Test Concrete 2 0.44 0.46 Trial Concrete 3 0.41 0.44 Test Concrete 4 0.38 0.38 Test Concrete 5 0.36 0.37

As shown in Table 2, when the concrete is manufactured using the concrete waterproofing material of the present invention, the waterproofing performance is improved. In particular, when using 0.9 to 0.95% with respect to the cement content, the performance was greatly improved.

<1-3> Compressive Strength Ratio Measurement

The compressive strength test was carried out at a age of 7, 8 days according to KS F 2405. The test body was produced according to KS F 2403, and cured at room temperature at 20 ± 3 ° C. humidity (60 ± 6)% after molding for 24 hours, followed by demolding. The solution is then cured until the strength test is carried out in water at a temperature of 20 ± 2 ℃. The number of test specimens was 5 for each age, the maximum value and the minimum value were discarded, and the average of the remaining three measured values was obtained. The compressive strength ratio was calculated according to the following equation.

Compressive Strength Ratio = Strength of Test Concrete (N / mm ² ) / Standard Concrete Strength (N / mm ² )

The results are shown in Table 3.

(Test method: KS F 2405) division Compressive strength ratio Control 7 days: 1 28 days: 1 Trial Concrete 1 7 days: 1.02 28 days: 1.08 Test Concrete 2 7 days: 1.02 28 days: 1.09 Trial Concrete 3 7 days: 1.035 28 days: 1.10 Test Concrete 4 7 days: 1.05 28 days: 1.19 Test Concrete 5 7 days: 1.06 28 days: 1.21

As shown in Table 3, it can be seen that the strength of the concrete is greatly improved when the concrete is manufactured using the concrete waterproofing material of the present invention. Specifically, when the concrete waterproofing material of the present invention is incorporated into concrete, it was confirmed that the compressive strength ratio of concrete was increased by 15 to 20% compared to the control group without the mixing of the concrete waterproofing material.

Test Example 2 Measurement of Chloride Ion Penetration Resistance (KS F 4926)

<2-1> Test Mortar

Test specimen mortar was prepared according to KS L 5109 in order to analyze the anticorrosive performance of the concrete waterproofing material of the present invention prepared in Example 1. Each test specimen mortar contains 0.8 wt%, 0.9 wt% and 0.95 wt% of the spherical waterproofing material of the present invention.

<2-2> Chlorine Ion Penetration Depth Measurement

Each test specimen mortar was immersed in 2.5% aqueous sodium chloride solution for 7 days. Thereafter, the resultant was dried at room temperature for 24 hours, and the test body was divided into two parts, and 0.1 N silver nitrate aqueous solution was sprayed onto the test object section which was divided into two parts, followed by spraying a 1% uranine aqueous solution in succession to measure the depth of three color development parts. The average value of the nine measured values obtained by measuring the depth of the color development portion of each of the three test specimens was determined to be the chloride ion penetration depth (Table 4).

(Test method: KS F 4926) Chloride ion penetration depth (mm) Test mortar 1 (contains 0.8 wt% of concrete waterproofing material) 0.16 Test mortar 2 (contains 0.9 wt% of concrete waterproofing material) 0.13 Test mortar 3 (contains 0.95% by weight of concrete waterproofing material) 0.12 Control (no treatment) 3.0

As shown in Table 4, it was confirmed that the specific waterproofing material composition of the present invention can be effectively used to prevent the flame, neutralization of concrete because it greatly inhibits the penetration of chloride ions.

As described above, the liquid spherical waterproofing composition of the present invention is characterized by a simple component and excellent waterproof and flame resistance. In addition, it is simple to manufacture and has the effect of reducing construction time and costs. Therefore, the concrete concrete waterproofing material composition of the present invention can be usefully used for waterproofing, anticorrosion, flame resistance or neutralization of concrete structures, civil structures, marine structures, wastewater treatment plants, waterworks, railways, bridges and the like.

Claims (4)

delete delete delete i) adding water to 15-25% by weight of oleic acid of the total weight of the liquid sphere waterproofing material to stir to form liquid oleic acid; ii) adding 1 to 10% by weight of fumed silica and water in the total weight of the liquid spherical waterproofing material to the reactant of step i) and then stirring for 30 to 90 minutes; iii) heating the reaction of step ii) to 50-60 ° C. and stirring; iv) adding 1 to 5% by weight of ammonia water and water to the reaction product of step iii) for 3 to 5 hours; And v) adding to the reactant of step iv) a fluidizing agent consisting of 1 to 5% by weight of a melamine-formaldehyde condensate of the total weight of the liquid spherical waterproofing material.