KR101867550B1 - Composition for waterproof of concrete structure - Google Patents

Abstract

The present invention relates to a liquid-phase absorption inhibitor. In other words, it is applied to the surface of concrete and permeates into the surface of concrete, thereby improving the waterproof and flame resistance of the surface layer of concrete. In particular, the anti-wrinkle agent according to the present invention improves the workability at the time of application by imparting rigidity by using the thixotropy improving agent and stays without falling down for a long period of time on the vertical surface. Therefore, even if it is applied to the vertical surface, There is an advantage.

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for preventing water absorption,

The present invention relates to a concrete absorber composition for preventing water from being infiltrated onto the surface of a concrete structure.

Concrete structures or reinforced concrete structures are degraded as they react with surrounding environmental elements after being built. Degradation of concrete can be divided into deterioration due to chemical action such as salting, neutralization and alkali aggregate reaction, and deterioration due to physical action due to repetition of freezing-thawing.

In the case of salting, the chlorine component flows into the concrete to destroy the passive film of the reinforcing bar and corrodes the reinforcing bar. When the rebar is corroded, the volume expands, cracking occurs on the concrete surface and peeling occurs. Chlorine attack occurs mainly when chlorine component penetrates into the concrete due to spraying of snow remover mainly composed of chlorine in winter, or chlorine component in the air is injected into the concrete at the coast.

Neutralization of concrete occurs when the atmospheric carbon dioxide gas is introduced into concrete and calcium hydroxide formed by concrete hydration reaction is converted into calcium carbonate. As the pH inside the concrete decreases, the passive film of the reinforcing bar is removed and the reinforcing bar is corroded as in the previous case.

The freezing and thawing effect also causes cracks in the concrete due to the volume change during the freezing and melting of the water penetrating into the concrete.

Most of these concrete deterioration occurs when deteriorated materials are introduced into the concrete in a state of being dissolved in water. Therefore, the concrete structure, especially the concrete bridge pavement, is waterproofed. There are various methods for waterproof treatment. A method of forming a protective layer on a top surface of a concrete pavement by a dry or spray method has been widely used. However, since the surface protective layer is not adhered to concrete, it is peeled off from the concrete surface to prevent deterioration of concrete, and it causes secondary contamination. Therefore, a method of increasing the waterproof property by penetrating the liquid waterproofing agent into the concrete has been suggested. Instead of forming a separate protective layer on the concrete surface, a liquid waterproofing agent permeates the surface of the concrete pavement to form a waterproof layer.

However, when the direction of the penetration of the waterproofing agent and the direction of gravity are different, such as the lower surface of the package (for example, the lower surface of the bridge) or the vertical surface of the road boundary stone, There is a problem in that the structure can not sufficiently penetrate and flow down.

Particularly, the boundary seams of the road or the outer side of the road are formed not only vertically but also as a place for laying the snow during the snow removal operation, so that the damage to the snow removal agent is much more serious. In addition, since the drainage port of the road pavement is installed in the central separator or the boundary area, contact with deteriorated materials such as chlorine and carbonic acid becomes more frequent and the damage of the deterioration becomes larger as compared with the road surface.

It is an object of the present invention to provide a liquid-permeation-type anticorrosive composition having improved adhesiveness and permeability to concrete and improved applicability to a vertical surface or a ceiling surface.

In order to accomplish the above object, the present invention provides a waterproofing agent for concrete, which is bonded to a concrete surface to prevent water from penetrating into the concrete; A diluent mixed with the waterproofing agent to dilute the waterproofing agent; And a thixotropy improving agent for controlling the degree to which the diluent and the waterproofing agent flow downward from the concrete surface to the bottom due to gravity action.

According to the present invention, the waterproofing agent may include any one of silane and polysiloxane or a mixture thereof, and the diluent is preferably volatile organic compounds (VOC).

In one embodiment of the present invention, the thixotropy improver comprises at least one of polyacrylate, polyacrylate sodium salt, polyacryl-ethyl acrylate copolymer, polymethyl methacrylate, polyacryl-ethyloxylate copolymer It is preferable to use a material of a polymer series.

Or as the thixotropy improving agent, at least one selected from the group consisting of cellulose acetate, 2-hydroxyethyl cellulose, cellulose acetate butyrate, cellulose triacetate, cellulose acetate propionate, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose sodium salt, Cellulose-based materials containing at least one of ethyl cellulose and ethyl cellulose may be used.

In another embodiment of the present invention, the thixotropy improving agent is a wax comprising at least one of paraffin wax, microcrystalline wax, polyethylene wax, polypropylene wax, cow vanilla wax, soy wax, rice wax, bayberry wax and montan wax A series of materials can be used.

In one embodiment of the present invention, the waterproofing agent may be blended in an amount of 30 to 70 wt%, the diluent 20 to 50 wt%, and the thixotropy improving agent 1 to 20 wt%.

The liquid absorptive inhibitor according to the present invention exhibits ricketting and acts as a sol state at the time of coating so that fluidity is ensured and the application is easy. After the application is completed, the liquid absorber is maintained in a gel state, . That is, even when the antidowsing agent according to the present invention is applied to the vertical surface, the antidispersing agent penetrates deep into the surface layer of the concrete because it stays in place for a long period of time, thereby ensuring waterproofness at the same level as applied to the horizontal surface.

Due to the ruggedness imparted by the thixotropic property improving agent, the liquid absorptive inhibitor according to the present invention is expected to exert excellent performance, in particular, by being applied to a bridge pier, a lower surface, a vertical surface of a boundary stone, and the like.

Figure 1 is a schematic view of a bridge.
2 is a view for explaining the chemical action of the waterproofing agent.
3 is a photograph of the vertical surface of the mortar specimen after application of the absorption inhibitor according to the comparative example.
Fig. 4 and Fig. 5 are photographs of the anti-absorption agent according to Examples 2 and 3, respectively, after they are applied to the mortar specimen.
6 is a cross-sectional photograph of the mortar specimen of Examples 2 and 3.
Fig. 7 is a photograph of a state in which the comparative example (left side) and the example 1 (right side) are coated on the vertical face of the mortar specimen and then water is sprayed.

Hereinafter, concrete absorbers according to one embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

The present invention relates to a concrete absorber. When applied to road pavement as a liquid composition, it permeates into the surface layer portion of the table surface to form a waterproof layer. Particularly, it is used for the packing layer of the bridge top plate. In other words, unlike ordinary roads, bridge pavement is not connected to the ground, so snow does not easily melt, so spray a large amount of snow remover. Therefore, bridges are the most severely damaged structure. Of course, the present invention is not limited to road pavement or bridge pavement, and can be applied to concrete structures.

The liquid composition according to the present invention can be applied to a horizontal plane (the upper surface of a road), but when applied to a vertical plane or a ceiling plane such as a central separator of roads, A large effect can be obtained. When the absorptive agent is applied to the horizontal surface, the direction of gravity acting on the absorptive agent and the direction to be infiltrated are mutually coincident, so that permeability is not a problem. However, when the direction of gravity acting on the absorption inhibitor is different from the direction of gravity acting on the vertical surface or the ceiling surface, there is a problem that the permeability of the concrete to the surface layer is weakened as the absorption inhibitor flows down.

The present invention is intended to provide an anticorrosive agent excellent in adhesion and permeability for a vertical surface and a ceiling surface, such as a separator (A) of a paved road, a bottom surface (B) of a bridge and a bridge pillar (C) as shown in Fig.

The anti-absorption agent according to the present invention is a mixture of a silane-based waterproofing agent, a diluent, and a thixotropic agent. Other additives may be included to improve the physical properties.

The silane-based waterproofing agent is applied to the concrete surface to form a waterproof layer with a certain thickness on the surface of the concrete. The silane-based material is characterized by being excellent in bonding with inorganic materials, especially SiO ₂ , and has a hydrophobic functional group and is excellent in water resistance.

2 is a view for explaining the chemical action of the silane-based waterproofing agent.

The concrete is mixed with the largest specific gravity for the improvement of strength, and the aggregate mainly consists of SiO ₂ component. A silane-based waterproofing agent such as silanol is bonded to the SiO ₂ of the concrete through a condensation reaction as shown in FIG. And the organic group (R) of the silane-based material is mainly hydrophobic. When the hydrophobic organic group is bonded to the structure that surrounds the silica, that is, the coated structure, the water can not enter the concrete but drains to the outside. That is, the upper surface layer of the concrete is modified to be hydrophobic.

In this embodiment, the silane used for imparting the concrete absorption inhibiting property is R _n Si (OR) _4-n (wherein R represents an alkyl group, an aryl group, an organic functional group, OR represents a methoxy group, an ethoxy group or an acetoxy group ) Can be used as the organic silane. More specifically, there may be mentioned methyldimethoxysilane, n-hexyltrimethoxysilane, phenyltrimethoxysilane, aminoethylaminopropyltrimethoxysilane, propyltrimethoxysilane, n-octyltrimethoxysilane, bis-triethoxy Silane, hexamethyldisilane and the like can be used.

In addition, polysiloxane usable in one embodiment of the invention _{R1 n - [Si (R2)} 2] Structure of -R3 and _{R1 n - [Si (R2)} 2] x [Si (OR) 2] Y -R3 ( wherein , R 1 represents an alkyl group, an aryl group, an organic functional group, R 2 represents an alkyl group, R 3 represents an alkyl group, an aryl group, an organic functional group, OR represents a methoxy, ethoxy or other organic functional group. More specifically, polydimethylsiloxane (number average molecular weight Mn 2000 to 20,000), polydimethylsiloxane-alkylmethylsiloxane copolymer, polydimethylsiloxane-methylphenylsiloxane copolymer, polydimethylsiloxane-methyl (stearoyloxyalkyl) siloxane copolymer , Polydimethylsiloxane-graft-polyacrylate, and the like can be used.

In the present invention, the silane-based material may be used alone, or at least two of them may be used in combination.

On the other hand, the diluent is for dissolving the silane-based material in powder form and diluting and dispersing it in a solution state. Silane-based materials can also be dissolved in water, but in this embodiment organic solvents, especially volatile organic compounds (VOC), are used. Further, in this embodiment, a substance having a small environmental impact, particularly a substance having a low ability to generate ozone, is used among the volatile organic compounds. For example, dimethyl carbonate and para-chlorobenzotrifluoride can be used as an exempt solvent, and ethyl lactate as a biodegradable solvent can also be used. In general use agents, acetone, isopropyl alcohol, toluene, xylene, cyclohexane, methyl ethyl ketone, n-hexane and the like can be used.

 The thixotropic modifier that plays the most important role in the present invention is to prevent the water repellent agent dispersed in the diluent from flowing downward from the concrete surface due to gravity. The anti-irrigation agent according to the present invention is intended to solve the problem that the absorption inhibitor does not penetrate into the surface layer of the concrete immediately after it is applied when the bridge is applied to the bridge, the lower surface of the bridge, . However, it is not desirable to simply increase the viscosity of the absorption inhibitor. This is because when the viscosity is increased only, the workability of coating the surface of the concrete remarkably decreases. Accordingly, the thixotropy improving agent used in the present invention solves the above problem by imparting thixotropic to the liquid absorption inhibitor. The roughening is a state in which the liquid is in a sol state close to a liquid state, and a gel state in which viscosity increases when the liquid is stable. That is, when the antidowsing agent is applied to the surface of the concrete, it acts in a sol state and is easy to apply. Once stabilized after being coated, the liquid-phase anti-absorption agent behaves in a gel state and does not flow down.

In the embodiment of the present invention, polymer-based, cellulose-based and wax-based thixotropy improving agents can be used.

Examples of the polymer type thixotropic improving agent include polyacrylate, sodium polyacrylate salt, polyacryl-ethyl acrylate copolymer, polymethyl methacrylate, polyacryl-ethyloxylate copolymer and the like.

Examples of the cellulose type thixotropic improving agent include cellulose acetate, 2-hydroxyethyl cellulose, cellulose acetate butyrate, cellulose triacetate, cellulose acetate propionate, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose sodium salt, Hydroxyethyl cellulose and the like can be used.

Examples of wax-based thixotropic agents include petroleum wax, paraffin wax, microcrystalline wax, synthetic wax, polyethylene wax, polypropylene wax, natural wax cow vanishing wax, soy wax, rice wax, bayberry wax, mineral wax Montan wax and the like can be used.

In the mixing ratio of the water repellent agent, the diluent and the thixotropic property improving agent described above, the water repellent agent may be compounded in the range of 30 to 70% by weight, the diluent 20 to 50% by weight, and the thixotropy improving agent 1 to 20% by weight.

When the waterproofing agent is added in an amount of less than 30%, the waterproofing function may be deteriorated due to insufficient amount of penetration into the concrete. If the waterproofing agent is added in excess of 70%, the waterproofing agent may remain on the concrete surface to cause pollution.

When the organic solvent used as the diluting agent is less than 20%, the waterproofing agent is not diluted properly and the effect is decreased. When the organic solvent is more than 40%, the waterproofing agent and the thixotropy improving agent are decreased.

The thixotropy improving agent is preferably contained in an amount of 1 to 20%. If it is less than 1%, it is difficult to impart plasticity. If it is more than 20%, there is a risk of damaging the capillary phenomenon, and it is difficult to penetrate the concrete of the waterproofing agent. That is, the waterproofing agent penetrates into the surface layer of the concrete along microcracks or pores of the concrete by capillary action or osmotic pressure. The thixotropy improving agent may not penetrate into the concrete surface layer due to the viscosity increase in a stable state.

The present inventors made experiments on the absorption resistance, the resistance to water permeation and the resistance against chloride ion penetration by making the absorption inhibitor according to the four examples and one comparative example by varying the amount of the liquid absorption inhibitor according to the invention.

The compositions of Examples 1 to 4 and Comparative Examples are shown in Table 1 below.

[Table 1]

Wherein A is trimethyloxymethylsilane, B is triethoxyoctylsilane, C is polydimethylsiloxane, D is dimethyl carbonate, E is isopropyl alcohol, F is polyacryl-co-ethyl acrylate, G is cow vanilla wax , And H: ethyl cellulose.

For example, in the case of Example 1, 150 g of trimethyloxymethylsilane, 150 g of triethoxyoctylsilane and 300 g of polydimethylsiloxane were diluted with 200 g of dimethyl carbonate, an organic solvent prepared in advance, and 150 g of isopropyl alcohol to prepare a low viscosity liquid compound. 20 g of polyacryl-co-ethyl acrylate and 30 g of cow vanishing wax were added and dissolved for 30 minutes by using a high-speed stirrer to prepare a concrete infiltration type liquid absorptive inhibitor. In the case of the remaining embodiments, the manufacturing method is the same. In the comparative example, only waterproofing agent and organic solvent were used, and no thixotropy improving agent was used.

First, the test was applied to mortar specimens.

Mortar specimens were prepared according to the standard and method of KS F 4930 "Liquid Absorbent for Concrete Surface Coating", and the above Examples 1 to 4 and comparative examples were applied to specimens. The applied amount for each test piece is 0.4 Liter / m ² . The results are shown in Table 2 below and in Table 3, respectively, for horizontal and vertical surfaces, respectively.

[Table 2]

[Table 3]

[Table 2] shows that the penetration depth of concrete in the surface layer of the water absorption inhibitor is much higher than the reference value of 2 mm in both Comparative Examples and Examples. Of these, Example 3 was found to penetrate most deeply at 6.2 mm, and Comparative Example was the lowest at 5.2 mm. In the case of the water absorption coefficient ratio, the reference value after the alkali resistance test after the low temperature and high temperature repetition resistance test is 0.1 or less, and after the accelerated weather resistance test, it is 0.2 or less. Examples 1 to 4 were about 0.02 to 0.06, and the comparative examples were 0.05 to 0.08, which was slightly higher than those of the examples. The chloride ion penetration performance was also as low as 0.01 for the examples compared to the comparative example (0.04). In all the items, the examples and the comparative examples were found to satisfy the standard values, and it was confirmed that the embodiments were small, but the infiltration performance and the functionality in the horizontal plane were superior to the comparative example.

The reference value for penetration depth is 2.0 mm, but it is 0.4 mm for comparative example. However, in Examples 1 to 4, penetration depths of 4.8 to 5.4 mm were found to be very high. In the case of the vertical surface, when the anti-absorption agent according to the comparative example is applied, the anti-absorption agent does not have time to permeate the concrete because it immediately flows down. However, in the case of this embodiment, It can penetrate deep into the concrete surface.

Fig. 3 is a photograph of the vertical surface of the mortar specimen after application of the absorption inhibitor according to the comparative example, and Figs. 4 and 5 are photographs of the absorption inhibitor according to the second and third embodiments, respectively, applied to the mortar specimen. In the case of Fig. 3, all of the absorption preventing agent flows down and the surface of the mortar specimen is directly exposed. However, in the photographs of FIGS. 4 and 5, it can be seen that the vertical absorption surface of the mortar specimen stays as it is. This difference can be explained by the difference in the action of the rheology modifier, and it can be confirmed from the test results of penetration depth to concrete. 6 is a cross-sectional photograph of the mortar specimen of Examples 2 and 3. It is possible to visually confirm that the absorber is completely penetrated into the concrete surface layer.

If the absorber does not penetrate into the concrete, it will surely degrade both the water absorption resistance, the water permeability and the chloride ion penetration resistance. The test results were the same. That is, the water absorption coefficient ratio in the water absorption resistance is 0.1 or less, and the water absorption coefficient ratio in the comparative example is 0.2 or 0.5, while the water absorption coefficient does not satisfy the standard value. However, in the case of Examples 1 to 4 according to the present invention, all of 0.02 to 0.06 were found to be excellent in all of the cases. These results are almost the same as the test results for the horizontal surface of the mortar specimen, and it can be seen that the performance of the absorber according to this embodiment is uniformly guaranteed in both the vertical surface and the horizontal surface.

In the case of permeability, the comparative example did not satisfy the reference value of 0.1 or less, whereas the comparative example did not satisfy the reference value of 0.1 or less, whereas the embodiments of the present invention showed a value much lower than the reference value of 0.02 to 0.05. The chlorine ion penetration resistance performance is a reference value of the bridging waterproofing of 1.0 mm or less and the other 3.0 mm or less, and the comparative example shows 2.0 mm, which does not satisfy the reference value for bridges. However, in the case of the embodiment according to the present invention, the chloride ion penetration resistance of 0.01 to 0.03 mm was found to satisfy not only the standard value but also the salt resistance at a very high level.

FIG. 7 is a photograph of a comparative example and Example 1, respectively, applied with water on a vertical surface of a mortar specimen. In the case of the comparative example (left side), water is absorbed as it is, whereas in case of Example 1 (right side), water drops are observed on the concrete surface. In the example, the water absorptive agent penetrates into the concrete surface layer to exhibit waterproof property, but in the case of the comparative example, the water absorptive property is remarkably lowered because the water absorptive agent is hardly penetrated.

As can be seen from the above results, the liquid-type absorptive inhibitor according to the present invention exhibits the plasticity and acts as a sol state at the time of coating to ensure fluidity, so that the application work is easy, and after the application is completed, So as to maintain its position. That is, even when the antidowsing agent according to the present invention is applied to the vertical surface, the antidispersing agent penetrates deep into the surface layer of the concrete because it stays in place for a long period of time, thereby ensuring waterproofness at the same level as applied to the horizontal surface.

Due to the ruggedness imparted by the thixotropic property improving agent, the liquid absorptive inhibitor according to the present invention is expected to exert excellent performance, in particular, by being applied to a bridge pier, a lower surface, a vertical surface of a boundary stone, and the like.

Claims (7)

delete delete delete delete A silane-based waterproofing agent which is bonded to the concrete surface to prevent water from penetrating into the concrete;
A diluent mixed with the waterproofing agent to dilute the waterproofing agent; And
And a thixotropy improving agent for controlling the degree to which the diluent and the waterproofing agent flow down from the concrete surface to the bottom due to gravity action,
The thixotropy improving agent may be selected from the group consisting of cellulose acetate, 2-hydroxyethylcellulose, cellulose acetate butyrate, cellulose triacetate, cellulose acetate propionate, methylcellulose, ethylcellulose, hydroxypropylcellulose, carboxymethylcellulose sodium salt, hydroxyethyl Wherein the cellulose-based material comprises at least one of cellulose and cellulose. A silane-based waterproofing agent which is bonded to the concrete surface to prevent water from penetrating into the concrete;
A diluent mixed with the waterproofing agent to dilute the waterproofing agent; And
And a thixotropy improving agent for controlling the degree to which the diluent and the waterproofing agent flow down from the concrete surface to the bottom due to gravity action,
Wherein the thixotropy improving agent is a wax-based material comprising at least one of paraffin wax, microcrystalline wax, polyethylene wax, polypropylene wax, cow vanishing wax, soy wax, rice wax, bayberry wax and montan wax Concrete anti-absorption agent. The method according to claim 5 or 6,
Wherein the waterproofing agent is formulated in an amount of 30 to 70% by weight, the diluent 20 to 50% by weight, and the thixotropy improving agent 1 to 20% by weight.

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