KR20030074092A - Inorganic composition of concrete repairing agent and concrete surface treatment method using the same - Google Patents

Abstract

PURPOSE: Provided is a composition of inorganic concrete repairing agent, a double-liquid type agent, which penetrates concrete structures easily, prevents steel corrosion and concrete deterioration, and improves strength and waterproofness. CONSTITUTION: The double-liquid type concrete repairing agent comprises the components of: (A) inorganic composition penetrative into concrete containing 40-96wt.% of anhydrous alcohol such as ethanol, methanol or 2-propanol, and 4-60wt.% of one or two more of silane-based compounds selected from trimethyl methoxy silane, triethyl methoxy silane, dimethylvinyl methoxy silane, dimethylvinyl ethoxy silane, phenyl trimethoxy silane, etc.; (B) inorganic composition preventive of concrete deterioration containing 5-25wt.% of one more of alkali silicate selected from sodium silicate and potassium silicate, 0.05wt.% of surfactant based on non-ions, anionic fluoride or silicon, and the remains of water. The surface of concrete is treated by spraying the (A) composition, leaving for 5-240min, and spraying the (B) composition.

Description

Composition for concrete inorganic repair agent and method for concrete surface treatment using same {INORGANIC COMPOSITION OF CONCRETE REPAIRING AGENT AND CONCRETE SURFACE TREATMENT METHOD USING THE SAME}

The present invention relates to an inorganic repair agent composition of concrete, and more particularly, to a two-component composition comprising a penetration-intensifying inorganic repair agent composition, and a degradation inhibitory inorganic repair agent composition and a surface treatment method of concrete.

The penetration-intensifying inorganic repair agent generally used at home and abroad is composed of alkali silicates. Such alkali-based silicates form calcium silicates by reacting with calcium ions, which are the main components of concrete, at a very high rate, even if the surface tension is small. The calcium silicate thus formed is an insoluble and chemically stable oxide that only protects the surface of the concrete and has a problem of not penetrating deep into the concrete because the penetration depth is only about 5 mm, thereby appropriately protecting the concrete structure. There is a drawback to not playing a role.

According to a UK study that examined the causes of damage to concrete structures in the past decades, corrosion caused by reinforcing steel accounts for 47% of the overall performance deterioration of the structure, and corrosion caused by salt damage accounts for 66%. It is known. In Korea, since the three sides are composed of the sea, there are many areas where damage can occur, as well as the four seasons are clearly affected by shrinkage and expansion, and the neutralization of the exhaust gases due to the concentration of cities is severe. The durability of concrete is worse than that of any country. According to the Seoul Metropolitan Report <Corporate Condition Survey and Prevention Measures for Concrete Structures> published in December 1997, some of the concrete structures managed by the city have been eroded, resulting in cracks, peelings or droppings in concrete. 18%. In addition, the ratio of maintenance of the structure accounted for more than 40% of Seoul's total construction budget in 2000. For the repair of the structure, not only Seoul but also the large-scale organizations use huge budgets for the repair. Is expected to continue to surge. In addition, in Tokyo, Japan, where our environment is similar, the maintenance cost of existing structures accounts for 47% of the total construction budget in 2000. In 2001, maintenance costs are expected to exceed new facilities.

The maintenance materials used for the maintenance of reinforced concrete structures are mainly resin-based and cement-based materials.However, the repair methods using these materials take action when the performance deterioration is in full swing. There are many. In addition, when repairing the section, it is necessary to remove the concrete that has degraded durability, and in this process, a large amount of noise, dust, vibration, construction waste, etc. increases the burden on the environment and economic burden. In addition, the impact caused by removing the concrete may cause damage due to cracks, etc., in the surrounding concrete, which is not deteriorated due to the impact. In addition, when reinforcing the structure using fiber reinforcement materials without improving the durability and reinforcing corrosion of the concrete, the structural function of the load is improved, but since the corrosion of the steel can be continued in the structure, the durability of the reinforced concrete It may not be effective for performance recovery.

The repair method currently in use is largely divided into surface coating method, crack injection method, and filling method according to the type of damaged part. The materials used for the surface coating method are beautifully colored, have excellent initial adhesive strength and chemical resistance, and are economical and workable, and many products are commercially available as paints. It hardens and causes peeling (floating), and it is easily broken by impact. In recent years, shrinkage and expansion rate have been achieved by using an aqueous paint or the like which has improved physical properties or by adding a silica material to the polymer material as a filler. And efforts to complement the brittle properties due to curing. However, the surface coating method is only a repair of the crack surface, so in the case of a progressive crack, the elongation of cracks is poor. Since the thickness of the coating material is thin, the durability of the repaired part is increased over time after repair. It is necessary to pay attention because it may be lowered. In addition, the material used for the surface coating method is used to protect the structure from deterioration factors rather than to improve the durability of the deteriorated concrete, and as shown in the present invention, In addition, there is a big difference in the functionality from the penetration-improving inorganic repair agent to improve the durability of damaged concrete.

In the case of the crack injection method, the crack injection material is an epoxy-based synthetic resin, which is most commonly used because of its small shrinkage and early strength, and excellent adhesive strength.However, the crack injection material is re-cracked after crack repair due to a very different elastic modulus and shrinkage expansion rate. There is a problem such as.

In the case of the filling method, an epoxy mortar or an acrylic mortar is used as a material to be used. This filling method removes the defects of the structure, mixes it with the cement mortar using an epoxy or acrylic resin at a constant mixing ratio, and then fills and installs the defective parts of the structure. Although it has excellent short-term adhesion, it can be surely repaired physically. However, it has not been able to build chemical treatment technology for each deterioration factor such as neutralization, salt, east sea, chemical corrosion, etc. The use of inorganic materials together can cause problems in the long-term integration with the mother.

Therefore, the new surface treatment method and weapon that can protect the interior and exterior of the concrete as well as waterproof while overcoming the disadvantages of the general surface coating method, the injection method and the filling method as described above and recovering the performance of the degraded concrete performance There has been a demand for repairs.

It is an object of the present invention to provide an effective concrete surface treatment method as described above.

Another object of the present invention is to provide a new type of inorganic inorganic repair agent as described above.

1 is a graph showing the penetration depth from the concrete surface according to the change of tetraethoxysilane.

2 is a graph showing the penetration depth from the concrete surface according to the use of the silane mixture.

3 is a graph showing the penetration depth from the concrete surface with the change of the solvent.

4 is a graph showing the penetration depth from the concrete surface according to the change of the silane series.

Figure 5 is a graph comparing the depth of penetration from the concrete surface of the composition according to the invention and a third party product.

Figure 6 is a graph comparing the depth of penetration from the concrete surface with the case of applying the composition for penetration-enhancing inorganic repair agent and the degradation inhibitory inorganic repair agent according to the present invention, respectively.

7 is a graph showing the results of the absorption test of the composition according to the present invention and other companies' products.

8 is a graph showing the results of the chloride immobilization of the composition according to the present invention and other companies' products.

Figure 9 is a graph showing the results of the chloride immobilization experiments with the case of applying the composition for penetration-enhancing inorganic repair agent and the degradation inhibitory inorganic repair agent according to the present invention, respectively.

In order to achieve the object as described above, the present invention, on the concrete surface, trimethyl methoxy silane, trimethyl ethoxy silane, dimethyl dimethoxy silane, dimethyl diethoxy silane, methyl trimethoxy silane, methyl triethoxy silane, tetramethoxy Methoxy silane, tetraethoxy silane, methyldimethoxy silane, methyl diethoxy silane, dimethyl ethoxy silane, dimethyl vinyl methoxy silane, dimethyl vinyl ethoxy silane, methyl vinyl dimethoxy silane, methyl vinyl diethoxy silane, diphenyldimeth 4 to 60 weights of one or two or more silane compounds selected from the group consisting of methoxy silane, diphenyldiethoxy silane, phenyltrimethoxy silane, phenyltriethoxy silane, octadecyltrimethoxy silane, and octadecyltriethoxy silane % And a first step of spraying a mixture of 40 to 96% by weight of anhydrous alcohol; And 5 to 25% by weight of alkali silicate consisting of at least one silicate of sodium silicate and potassium silicate and 0.05% by weight or less of nonionic or anionic fluorine-based or silicon-based surfactant after 5 to 240 minutes. It provides a concrete surface treatment method comprising a; the second step of spraying a mixture filled with 100% by weight.

The present invention also provides trimethylmethoxy silane, trimethylethoxy silane, dimethyldimethoxy silane, dimethyldiethoxy silane, methyltrimethoxy silane, methyltriethoxy silane, tetramethoxy silane, tetraethoxy silane and methyldimethoxy silane. , Methyl diethoxy silane, dimethyl ethoxy silane, dimethyl vinyl methoxy silane, dimethyl vinyl ethoxy silane, methyl vinyl dimethoxy silane, methyl vinyl diethoxy silane, diphenyl dimethoxy silane, diphenyl diethoxy silane, phenyltrimeth 4 to 60% by weight of one or two or more mixtures selected from the group consisting of oxysilane, phenyltriethoxy silane, octadecyltrimethoxy silane, and octadecyltriethoxy silane, and 40 to 96% by weight of anhydrous alcohol, Alkali silicate consisting of at least one silicate of the concrete penetration strengthening inorganic repair composition (A), sodium silicate and potassium silicate Concrete deterioration inhibiting inorganic repair composition (B) comprising 5 to 25% by weight of 100% by weight of a mixture of 0.05% by weight of a nonionic or anionic fluorine- or silicone-based surfactant with distilled water, and (A) and (B It provides a two-component concrete inorganic repair composition containing all).

The inorganic repair composition according to the present invention has a two-component structure of a silane compound and an alkaline silica, and the concrete surface treatment method according to the present invention overcomes the disadvantages of conventional surface coating methods, injection methods, and filling methods. It consists of two steps to do this.

Therefore, when using such a method and composition, it is possible to protect the interior and exterior of the concrete as well as waterproof while restoring the performance of the deteriorated concrete performance, due to deterioration factors such as salting or neutralizing the existing concrete structure When corrosion of reinforcing bars, cracking and dropping of coated concrete occur, and the durability of concrete decreases, neutralization after repair by improving the pH of concrete or fixing salts that have penetrated into concrete with anti-corrosion treatment of corroded reinforcing bars By suppressing secondary corrosion of reinforcing bars due to salt damage and improving the strength and watertightness of concrete, it is possible to improve the durability performance of the deteriorated concrete.

As described above, the present invention relates to a silane composition, in particular trimethylmethoxy silane, trimethylethoxy silane, dimethyldimethoxy silane, dimethyldiethoxy silane, methyltrimethoxy silane, methyltriethoxy silane, tetramethoxy silane, Tetraethoxy silane, methyldimethoxy silane, methyl diethoxy silane, dimethyl ethoxy silane, dimethyl vinyl methoxy silane, dimethyl vinyl ethoxy silane, methyl vinyl dimethoxy silane, methyl vinyl diethoxy silane, diphenyl dimethoxy silane, 4 to 60% by weight of a mixture of one or more selected from diphenyldiethoxy silane, phenyltrimethoxy silane, phenyltriethoxy silane, octadecyltrimethoxy silane and octadecyltriethoxy silane, and 100% anhydrous alcohols. Alkali silicate 5 having a molar ratio of SiO ₂ / Na ₂ O to SiO ₂ / K ₂ O and a molar ratio of SiO ₂ / Na ₂ O to SiO ₂ / K ₂ O, which is uniformly mixed after addition to% ˜25 weight percent; Lithium polysilicate 2.5-22 wt%; The non-ionic or anionic fluorine-based surfactant for reducing the surface tension is characterized in that it contains less than 0.05% by weight and the portion of the degradation inhibitory mixed composition (B) filled with distilled water is physically separated.

In particular, the penetration-enhancing composition consists of a mixture of silane-based compounds and anhydrous alcohols. Since they do not contain water, they have a small surface tension and can penetrate deep into the concrete. Will be. After sufficient time to penetrate the concrete, the secondary silica silicate is sprayed, and the moisture contained in the alkali silicate penetrates into the concrete in advance, and the silane system is hydrolyzed by the moisture to form nano-sized silica. Alcohol is formed. Nano sized silica prevents fine pores inside the concrete by gelation, thereby increasing the strength deep inside the concrete, inhibiting penetration of deteriorated materials, waterproofing and neutralizing. In addition, the alkali-based silica in the deterioration inhibiting composition reacts with calcium ions, which is the main component of the concrete, to form insoluble calcium silicate on the concrete surface and to protect the surface of the concrete by forming a compound having high acid resistance and alkali resistance.

Therefore, when the construction using the two-step method and two-component composition as in the present invention, to form a physical, chemically stable concrete structure on the interior and surface of the concrete structure.

Hereinafter, the present invention will be described in more detail with reference to the following examples. The following Examples are only examples for more specifically examining the present invention, and the present invention is not to be construed as being limited by the following Examples. In the examples,% means% by weight.

Example 1

After filling the tetraethoxy silane 5%, 10%, 20%, 30%, 50%, 80%, respectively, the remainder was mixed with ethanol to 100% by weight to prepare a penetration-enhancing composition (a). Tetraortho silicate (TEOS) was mixed with ethanol that passed through the water absorption column to prevent water from being contained in the solvent, and then dissolved in a glass bottle by adding a very small amount of phenolphthalein to check the penetration of concrete. Stored.

10% sodium silicate having a SiO ₂ / Na ₂ O molar ratio of 2.2 or more, lithium polysilicate 20%, fluorine-based surfactant 0.05%, distilled water 69.95%, and uniformly mixed so as to have a total weight of 100% (b) Prepared.

The penetration inhibiting composition (a) thus prepared was wetted on the concrete surface, and after 2 hours, the degradation inhibitory composition (b) was applied. After 24 hours, in order to determine the physical characteristics of the composition for penetration-reinforced inorganic repair agent, the compressive strength test described below and the penetration depth test were conducted and evaluated.

The concrete used in the experiment used ready-mixed concrete to produce specimens under the same mixing conditions. Table 1 shows the concrete mix table used in this experiment.

Water / cement ratio (%) Fine Aggregate Rate (%) Air volume (%) Slump (cm) Unit content (kg / ㎥) water cement sand Pebble Air entrainment 54.9 47.7 4.5 10 168 306 871 963 0.92

Example 2

30% by weight of tetraethoxy silane was mixed with 70% by weight of ethanol to prepare a penetration-enhancing composition. After mixing 20% by weight of lithium polysilicate and 0.05% by weight of fluorine-based surfactant and sodium silicate having a SiO ₂ / Na ₂ O molar ratio of 2.2 or more, respectively, 5%, 15%, 30%, 45%, 60%, 75% Distilled water was evenly mixed so that the total weight was 100% to prepare a deterioration inhibiting composition.

After applying the prepared composition to the same concrete specimens as in Example 1 in the same manner as in Example 1, in order to determine the physical properties by comparing the compression strength test and the neutralization inhibitory test described later was compared and evaluated.

Example 3

A penetration-enhancing composition was prepared by mixing 70% by weight of ethanol with 30% by weight of tetraethoxy silane. 10% by weight of sodium silicate having a SiO ₂ / Na ₂ O molar ratio of 2.2 or more, 0.05% by weight of fluorine-based surfactant, and 5%, 10%, 20%, and 40% of lithium polysilicate, respectively, and then mixed Distilled water was mixed evenly so as to be 100% to prepare a deterioration inhibiting composition.

After applying the prepared composition to the same concrete specimens as in Example 1 in the same manner as in Example 1, in order to grasp the physical properties of the inorganic repair agent was performed by comparing the compression strength test and the neutralization inhibitory test to be described and evaluated.

Example 4

A penetration-enhancing composition was prepared by mixing 70% by weight of ethanol in 30% by weight of a mixture of ten silane compounds including tetraethoxy silane. In addition, 10% by weight of the sodium silicate having a SiO ₂ / Na ₂ O molar ratio of 2.2 or more, 20% by weight of lithium polysilicate, 0.05% by weight of fluorine-based surfactant, and 69.95% by weight of distilled water are mixed so that the total weight is 100%. Was prepared.

After applying the prepared composition to the same concrete specimens as in Example 1 in the same manner as in Example 1, in order to determine the physical properties of the inorganic repair agent by performing the compressive strength test, water absorption test and neutralization inhibition test described below to compare and evaluate It was.

Example 5

Ten kinds of silane-based compounds including tetraethoxy silane were mixed with 30 wt% of the mixture, 70 wt% of 2-propanol (isopropyl alcohol) and 70 wt% of methanol, respectively, to prepare two kinds of penetration strengthening compositions. In addition, 10% by weight of the sodium silicate having a SiO ₂ / Na ₂ O molar ratio of 2.2 or more, 20% by weight of lithium polysilicate, 0.05% by weight of fluorine-based surfactant, and 69.95% by weight of distilled water are mixed so that the total weight is 100%. Was prepared.

After applying the prepared composition to the same concrete specimens as in Example 1 in the same manner as in Example 1, in order to determine the physical properties of the inorganic repair agent by performing the compressive strength test, penetration depth experiment and neutralization inhibitory test described below, Evaluated.

Example 6

30% by weight of tetraethoxy silane and 70% by weight of ethanol were mixed to prepare a penetration strengthening composition. 5% by weight of sodium silicate having a SiO ₂ / Na ₂ O molar ratio of 2.2 or more, 5% by weight of lithium polysilicate, 10% by weight of a fluorine-based surfactant, and 5% of potassium silicate having a SiO ₂ / K ₂ O molar ratio of 2.2 or more, respectively. After containing 10%, 20%, 30%, 50% differently, distilled water was mixed evenly so that the total weight was 100%, and five deterioration inhibiting compositions were prepared.

After applying the prepared composition to the same concrete specimens as in Example 1 in the same manner as in Example 1, in order to grasp the physical properties of the inorganic repair agent was performed by comparing the compression strength test and the neutralization inhibitory test to be described and evaluated.

Example 7

To 70% by weight of ethanol, trimethylethoxysilane, dimethyldiethoxysilane, and octadecyltrimethoxysilane were included 30% to prepare a composition for penetrating-intensity inorganic repair. In addition, 10 wt% of sodium silicate having a SiO ₂ / Na ₂ O molar ratio of 2.2 or more, 20 wt% of lithium polysilicate, and 0.05 wt% of a fluorine-based surfactant were then mixed equally with 69.95 wt% of distilled water to prepare a deterioration inhibitor. It was.

After applying the prepared composition to the same concrete specimens as in Example 1 in the same manner as in Example 1, in order to determine the physical properties of the inorganic repair agent by performing the compressive strength test, penetration depth experiment and neutralization inhibitory test described below, Evaluated.

Example 8

30% by weight of tetraethoxy silane and 70% by weight of ethanol were mixed to prepare a composition for penetration strengthening inorganic repair. In addition, 10% by weight of sodium silicate having a SiO ₂ / Na ₂ O molar ratio of 2.2 or more, 20% by weight of lithium polysilicate, 0.05% by weight of fluorine-based surfactant, and 69.95% by weight of distilled water were deteriorated to 100% by weight. A composition for the inhibitory inorganic repair agent was prepared.

The prepared composition was compared and evaluated with other companies' products (Radcon's Radcon # 7 and Surtreat's GPHP products; hereinafter referred to as R and S products, respectively), and the experimental items were the compressive strength test, penetration test, and neutralization inhibition described below. Capacity test, chemical resistance test, water absorption test, chloride immobilization test.

Example 9

30% by weight of tetraethoxy silane and 70% by weight of ethanol were mixed to prepare a composition for penetration-improving inorganic repair agent (a) and 10% by weight of sodium silicate having a SiO ₂ / Na ₂ O molar ratio of 2.2 or more and lithium polysilicate Was prepared by mixing 20% by weight, 0.05% by weight of fluorine-based surfactant and 69.95% by weight of distilled water so that the total weight is 100% by weight to prepare a composition for inhibiting deteriorating inorganic repair (b).

The inorganic repair preparations a and b prepared as described above were subjected to comparative evaluation experiments with the inorganic repair preparations of the R and S companies described above.

The following experiments were carried out on the composition obtained according to the above embodiment.

Experiment 1: Compressive Strength Experiment

In order to examine the effect on the compressive strength of concrete, the composition prepared in Example 1 was applied to a cylindrical specimen having a diameter of 100 mm × 200 mm in the same manner as in Example 1, and then wet curing in a room at a temperature of 23 ° C. for 24 hours. After sufficient water supply by sprinkling, dry curing (temperature 23%, relative humidity 55%) was performed for 4 days, and then the compressive strength test was performed. In the compressive strength test, the compressive strength was measured by pressurizing the load until the specimen was destroyed at a constant speed within 1.5 ~ 3.5kgf / cm2 per second using the universal testing machine according to KS F 2405. Table 2 to Table 10 show the experimental results of the compressive strength enhancement effect of the composition prepared in each example.

Table 2 shows the results of measuring the compressive strength using the inorganic repair composition prepared by varying the addition rate of tetraethoxy silane in the penetration-enhancing composition according to Example 1.

When the addition rate of tetraethoxysilane was 30%, it showed the highest strength-promoting effect, and when the tetraethoxysilane was added 5% or more, it was found that a predetermined effect could be obtained in terms of strength. This is because tetraethoxysilane not only penetrates the concrete and fills the pores therein, but also the alkali-based silicate coated on the surface reacts with calcium hydroxide, a hydrating component of cement, to form a C-S-H gel, which shows strength enhancing effect. When the C-S-H gel is in contact with water, the volume increases, filling the fragile tissues such as voids and cracks in the concrete, thereby densifying the concrete structure.

Tetraethoxysilane addition rate 0% 5% 10% 20% 30% 50% 80% Compressive strength (kgf / cm ² ) 158 172 189 204 221 202 208 Compressive strength increase rate (%) - 8.86 19.62 29.11 39.87 27.85 31.65

Table 3 shows the results of measuring the change in compressive strength using the composition prepared by changing the addition rate of sodium silicate in the composition for inhibiting deterioration inorganic repair according to Example 2. As can be seen from Table 3, the most significant increase in strength was achieved when the addition rate of sodium silicate was 30% and 45%. When sodium silicate was used at more than 15% but less than 60%, a predetermined effect was observed in terms of strength. It can be seen as obtaining.

The silicate is water soluble and alkaline, which is good for the recovery of neutralized concrete. The silicate reacts with calcium hydroxide produced by the hydration of cement to produce insoluble calcium silicate, making the concrete structure dense.

In the present invention, the actual reaction of the alkali silicate is as follows.

Na ₂ SiO ₃ + yH ₂ O + xCa (OH) ₂ → xCaSiO ₂ yH ₂ O + ₂ NaOH

Sodium silicate 0% 5% 15% 30% 45% 60% 75% Compressive strength (kgf / cm ² ) 158 162 178 221 220 187 165 Compressive strength increase rate (%) - 2.53 12.66 39.87 39.24 18.35 4.43

Table 4 shows the results of measuring the change in compressive strength using the composition prepared by changing the addition rate of lithium silicate in the degradation inhibitory composition according to Example 3. It can be seen that when the addition rate of the lithium silicate is 20%, the greatest strength enhancing effect is exhibited, and when the lithium silicate is added by 5% or more, a predetermined effect is obtained in terms of strength enhancement.

Lithium Polysilicate Addition Rate 0% 5% 10% 20% 40% Compressive strength (kgf / cm ² ) 158 185 198 221 190 Compressive strength increase rate (%) - 17.09 25.32 39.87 20.25

Table 5 below shows the results of measuring compressive strength using the composition prepared according to Example 4. Ten kinds of silane mixtures containing tetraethoxysilane in the penetration-enhancing composition showed a similar compressive strength enhancement effect as the case of using only tetraethoxysilane.

Coating material No treatment Tetraethoxysilane Silane mixture Compressive strength (kgf / cm ² ) 158 221 217 Compressive strength increase rate (%) - 39.87 37.34

Table 6 below shows the results of measuring compressive strength using 2-propanol and methanol, respectively, as solvents of the composition for penetrating-hardening inorganic repair agents according to Example 5. Not only ethanol but also 2-propanol and methanol exhibit sufficient strength enhancing effects and can be used as a solvent.

menstruum No treatment ethanol 2-propanol Methanol Compressive strength (kgf / cm ² ) 158 217 214 205 Compressive strength increase rate (%) - 37.34 35.44 29.75

The results of measuring the change in compressive strength by changing the addition rate of potassium silicate in the degradation inhibitory composition according to Example 6 are shown in Table 7 below. The addition rate of potassium silicate showed the greatest strength enhancing effect at 20%, and it was found that a predetermined effect could be obtained when added at 5% or more.

Potassium Silicate Addition Rate 0% 5% 10% 20% 30% 50% Compressive strength (kgf / cm ² ) 158 199 204 224 215 208 Compressive strength increase rate (%) - 25.95 29.11 41.77 36.08 31.65

The compressive strengths of the silane compounds used in the penetration enhancing composition according to Example 7 were measured. Trimethylethoxysilane, dimethyldiethoxysilane, and octadecyltrimethoxysilane all exhibit sufficient compressive strength enhancing effects, and any of the silane mixtures may be considered sufficient.

Silane type No treatment Tetraethoxysilane Trimethylethoxysilane Dimethyldiethoxysilane Octadecyltrimethoxysilane Compressive strength (kgf / cm ² ) 158 221 194 211 187 Compressive strength increase rate (%) - 39.87 22.78 33.54 18.35

According to Example 8, the compressive strength measurement results of the R company and S company products which are commonly used as the penetration strengthening composition, and the composition according to the present invention are shown in Table 9 below. The composition according to the present invention showed that the compressive strength enhancement effect was about 2.4 times and 1.9 times higher than that of other products, and it was confirmed that there was an excellent effect on the performance improvement of the concrete structure.

Kinds No treatment Composition according to the invention R company products S company product Compressive strength (kgf / cm ² ) 158 221 184 191 Compressive strength increase rate (%) - 39.87 16.46 20.88

Composition a for penetration-enhancing inorganic repair agent according to Example 9 and composition b for degradation inhibitory inorganic repair agent, R and S products currently used in Australia and the United States and the compressive strength measurement results are shown in Table 10 below. It was. Composition a for penetration-enhancing inorganic repair composition according to the present invention is about 2.3 times and 1.8 times the compressive strength enhancement effect compared to other imported products, the composition b for degradation inhibitory inorganic repair agent is 1.5 times and 1.2 times the compressive strength enhancement effect Appeared to be higher, even when the composition for penetrating-hardening inorganic repair agent and the composition for inhibiting deteriorating inorganic repair agent according to the present invention, respectively, it was confirmed that there is an excellent effect on the performance of the concrete structure.

Kinds No treatment Composition according to the invention R company products S company product a b Compressive strength (kg / cm ² ) 158 215 198 184 191 Compressive strength increase rate (%) - 37.98 25.32 16.46 20.88

Experiment 2: Penetration Depth Experiment

In order to determine the depth of the composition according to the present invention to penetrate into the concrete, the composition for the two-component inorganic repair agent according to the present invention on one side of a 100 mm × 100 mm × 100 mm concrete test body subjected to standard curing for 28 days is the same method as Example 1 After application for 24 hours, a wet curing (sufficient water supply by spraying) was performed in a room at a temperature of 23 ° C. for 24 hours, and then dried for 4 days (23% of temperature and 55% of relative humidity), and the penetration depth was measured. As described in Example 1, a very small amount of phenolphthalein may be added to prepare a penetration-enhancing composition as described in Example 1, and the measurement may be performed up to the depth of reddish red color inside the concrete. Phenolphthalein is a substance that develops red cerise color when it comes into contact with calcium hydroxide (Ca (OH) ₂ ) of concrete. After applying the two-component inorganic repair composition according to the present invention, the concrete specimen is split in half and the red cerise color develops. Up to 0.02 mm was measured with a vernier caliper. 1 is a graph showing the results of penetration depth of the composition according to Example 1 in FIG. 1. As a result of measuring the change of the penetration depth according to the change of the tetraethoxysilane, it was confirmed that the penetration force decreased when the content of the tetraethoxysilane was 50% or more, and when the content of the tetraethoxysilane was 30% or less, It was confirmed that the penetration power is secured. Considering that the reinforcement depth of the general concrete structure is 25 mm, it can be concluded that the penetration enhancer of the present invention sufficiently penetrates to the reinforcement depth of the concrete to exert the reinforcing effect of the concrete sphere.

The penetration depth of the composition according to Example 4 is shown graphically in FIG. As a result of measuring the change of penetration depth according to the use of the silane mixture, it was confirmed that sufficient penetration power can be obtained even when 10 kinds of silane mixtures including tetraethoxysilane were used.

3 shows the results of the penetration depth of the composition according to Example 5 in a graph. As a result of measuring the change in penetration depth according to the change of solvent, it was confirmed that similar penetration depth can be obtained by using 2-propanol and methanol as a solvent in addition to ethanol.

4 is a graph showing the results of experiments on penetration depth by changing the type of silane compound according to Example 7. In addition to tetraethoxysilane, silane-based compounds were changed to trimethylethoxysilane, dimethyldiethoxysilane, octadecyltrimethoxysilane, etc., but all exhibited sufficient depth of penetration. It was confirmed that it can be done.

5 is a graph showing the depth of penetration measured in the case of using the composition according to the present invention according to Example 8 and the R and S products of the imported products. In case of the R company product, the penetration depth is 4mm, and in the case of the company S company, the penetration depth is 6mm, but when the composition according to the present invention is used, the penetration depth is 34 mm, indicating that the composition according to the present invention has an excellent penetration force into the concrete structure. Could know.

6, the penetration depth of the composition permeation strengthening inorganic repair composition a according to the present invention according to Example 9, the composition for degradation inhibitory inorganic repair agent b and the imported product R company and S company product were used One graph is shown. In case of the R company, the penetration depth was 4 mm, and in the case of the S company, the penetration depth was 6 mm, but the penetration depth was 37 mm and the degradation inhibitory inorganic repair composition b was used when the composition according to the present invention was used. The penetration depth was 11mm. Penetration-enhancing inorganic repair composition a according to the present invention was excellent in penetration power to the concrete structure, the degradation inhibitory inorganic repair agent composition b was also found to be superior to the penetration of the concrete structure compared to the existing product.

Therefore, in the case of using the composition according to the present invention, it fills the pores by excellent penetration force, forms a certain protective layer up to the depth of the reinforcement of the reinforcement to exhibit the effect of inhibiting the corrosion of the reinforcing bars, and thus serves as an inorganic repair agent and a waterproof role. It can be seen that the improvement. In addition, the third-party products imported from the United States and Australia can be used to protect the surface of the concrete rather than the effect of reinforcing concrete, neutralizing performance recovery and reinforcement corrosion, but the composition according to the present invention As well as protection, it can be seen that it can play an excellent role in concrete reinforcement, neutralization performance recovery and reinforcement corrosion inhibition.

Experiment 3: Neutralization Inhibitory Performance Experiment

After applying the composition for inorganic repair preparation prepared according to Examples 2, 3, 6 and 8 on the surface of 100mm × 100mm × 100mm concrete test body subjected to standard curing for 28 days, the temperature 23 for 24 hours. Wet curing (sufficient water supply by watering) at room temperature was performed, and then dried for 4 days (23% temperature, 55% relative humidity) to prepare a test specimen for neutralization inhibition performance. The test specimens were placed in a chamber having a temperature of 30 ° C., a relative humidity of 60%, and a carbon dioxide concentration of 10% for 90 days. The specimens subjected to the neutralization promotion experiment were split in half and sprayed with a phenolphthalein solution, and then the depth to the reddish red color was measured. As a result of the neutralization inhibitory performance test, the concrete without the composition according to the present invention was found to have a neutralization depth of 23 mm, but the progress of the neutralization in the concrete specimen coated with the composition according to the present invention and the products of the R company and the S company was Hardly observed. From these results, it was confirmed that both the present invention and the imported products R company and S company product had an excellent effect on the neutralization inhibitory performance.

Experiment 4: Resistance to Chemicals

The composition prepared according to Example 8 was coated on the concrete surface according to the method described in Example 8 and coated using imported products R and S products to confirm the resistance to various chemicals. Resistance tests on chemicals were performed using the 1308 Spot Test Open. Each surface was divided into six equal areas, and the test drug was applied in the form of a drop of approximately 1 ml to observe the phenomenon on the surface for 15 minutes. The chemicals used were HCl, H ₂ SO ₄ , NaOH, NH ₄ OH, lead-free gasoline, and the experimental results are shown in Table 11.

The comparison between the coated and uncoated compositions according to the invention with respect to chemical reagents showed similar alkali corrosion results in alkaline solutions, but in acid solutions, those coated with concrete were not coated on the concrete surface. The big difference is shown. And when the composition according to the present invention and the imported product R company and S company product were compared, the alkali solution showed similar alkali corrosion results, but in acid solution, the present invention had superior resistance to chemicals compared to the imported product. Indicated.

Recently, the acceleration of air pollution caused by industrial development is the cause of acid rain. Acid rain not only rapidly weakens the structure of concrete, but also causes shortening of life due to reinforcing corrosion and neutralization. When the composition according to the present invention is coated, it can be obtained that chemically stable calcium silicate is formed on the concrete surface from preventing the corrosion of the concrete surface due to the strong acid from the result of not causing a bad result even with the strong acid reagent. .

reagent concrete Uncoated (not coated) Composition according to the invention R company, S company product 31% HCl Maintains droplet shape, very fast response, yellow drops appear, hole with large final surface, and discoloration is not permanent Unfolded on the surface, very slow reaction, almost no yellow droplets, almost no holes, discoloration is not permanent Spread on surface, somewhat slow reaction, slight yellow droplets, small holes, discoloration not permanent 15% H ₂ SO ₄ · Drop-shaped maintenance, reaction occurs slowly, small bubbles occur, white bubbles, some holes in final surface, discoloration is not permanent · No droplet shape, spreads rapidly, almost no reaction · almost no foaming · almost no surface corrosion · discoloration is not permanent · Small bubble appearance, rapid spreading, slow reaction, almost no foaming, faint white foam, slight surface corrosion, discoloration is not permanent 34% NaOH The surface is wet and spreads quickly and is not reactive.The final surface has no effect.No discoloration The surface is wet and spreads quickly and is not reactive.The final surface has no effect.No discoloration The surface is wet and spreads quickly and is not reactive.The final surface has no effect.No discoloration 34% NH ₄ OH The surface is wet and spreads quickly and is not reactive.The final surface has no effect.No discoloration The surface is wet and spreads quickly and is not reactive.The final surface has no effect.No discoloration The surface is wet and spreads quickly and is not reactive.The final surface has no effect.No discoloration Lead free gasoline Slow spreading, Wet surface, No reactivity, Fully evaporated, No stain Very spreading, wet surface, no reactivity, completely evaporated, no stain Quick spread, wet surface, no reactivity, completely evaporated, no stain

Experiment 5: Absorption Rate Experiment

For the absorption experiment, the composition of the two-component inorganic repair agent was applied to a 100 mm diameter 100 mm columnar specimen by the method of Example 1, and then the sides of the test specimen were coated with epoxy to induce one-way penetration. Absorption rate test was performed to measure the weight of the specimen before absorption in order to allow the surface coated with the inorganic refining agent to be submerged in water and to examine the ratio of absorption rate over time, and then consider the hydrophilicity of the silicate for 24 hours Specimen weight was measured by immersion in natural drying and water at intervals. The measurement method was taken out every time the weight of the specimen after absorption, wiped with a dry moisture absorbent cloth to remove the water on the surface, and weighed to 0.01g. Absorption rate was obtained by subtracting (weight of specimen before absorption) from (weight of specimen after absorption) and dividing by (weight of specimen before absorption) and multiplying by 100.

Figure 7 shows the results of the absorption rate of the composition prepared according to Example 8 in a graph. As shown in FIG. 7, the composition according to the present invention shows stable absorption after 48 hours of repeated deposition and drying once. Since the composition according to the present invention is hydrophilic, the initial absorption rate is higher than that of the coating with epoxy or urethane, but the inorganic water-repellent composition penetrating into the concrete requires H ₂ O in the process of forming the CSH gel. Because of this hydrophilicity, the water vapor inside the concrete is dissipated and the water penetrating from the outside absorbs little more than about 1% of the water required for the reaction. When the surface of the concrete structure is treated with epoxy or polyurethane, the moisture inside the concrete is not discharged, and the steel reinforcement embedded in the concrete provides an easy environment to corrode and causes secondary deterioration. Therefore, when the composition according to the present invention is used as a concrete inorganic repair agent, it is to prevent the deterioration due to the corrosion of the concrete structure by forming a structure capable of discharging the water with the hydrophilic properties. In the case of the composition according to the present invention, the difference between the absorption rate during deposition and the absorption rate during the wet and dry conditions is 0.11%, while maintaining a very stable state while the imported products of the R company and the S company are deposited. The difference in absorption rate between the wet and the wet is 0.37% and 0.39%, and the absorption rate is continuously increased even if the deposition and the wet and dry are repeated seven times. This is because, as found in the penetration depth test, the products of R and S, which are imported products, exhibit void filling and concrete strengthening effects only on the concrete surface, whereas the present invention penetrates deep into the inner surface of the concrete structure to form a network between inorganic repair agents. to be.

Experiment 6: Chloride Immobilization Experiment

In order to determine the degree of chloride immobilization, 0.7 kg of chloride per 1 m ^{3 of} concrete was mixed during concrete mixing, and then the two-component inorganic repair agent prepared according to Example 1 was applied according to the described method for 24 hours. Chloride concentration was measured after wet curing (sufficient water supply by watering) in a room temperature of 23 ° C. Chloride content was measured by taking 20 g of sample at 10mm interval from the concrete surface, and then using chloride ion extraction method AG-100 according to the Japan Concrete Engineering Association's draft (Method of Measuring Salt Content in Hardened Concrete). .

8 is a graph measuring chloride immobilization effect when the composition according to Example 8 and the products of R and S which are imported products are coated. The product of GPHP of R company and S company, which are imported products, showed a significant decrease in chloride immobilization effect from 10mm or more from the concrete surface and little effect of chloride immobilization from 20mm or more. Regardless, the chloride immobilization effect was found to be very high.

9 shows the immobilization effect of chloride when the composition a for penetration-reinforcement inorganic repair agent a and the composition for degradation inhibitory inorganic repair agent b according to Example 9 are applied, respectively and when the R and S companies, which are imported products, are coated. It is a graph measured. The composition a for the penetration-reinforced inorganic repair agent had a higher chloride immobilization effect than the imported products R and S regardless of the depth of the concrete, and the composition for degradation inhibitor inorganic repair agent was also immobilized to 20mm from the concrete surface. The effect of the immobilization of chloride was higher than that of R and S imported products.

The main component of rebar is iron (Fe). Iron is very reactive with chlorine ions in chloride compared to other anions. In other words, when using sea ions containing chlorine ions or reinforcing bars to increase tensile strength in concrete structures directly affected by sea water, such as coastal bridges or breakwaters, corrosion of ferric chloride or iron oxides may occur. do. When the steel is corroded or oxidized, the cracking of the concrete is accelerated by the expansion force due to the formation of the corrosion product of the steel. Therefore, when the inorganic repair agent of the present invention is applied to concrete structures and coastal bridges and breakwaters using sea sand, the effect of suppressing the corrosion of reinforcing bars is exerted. This is because the present invention penetrates into the concrete, and the silica component and chloride ions react to form silicate gels (SiO ₂ · nNaCl) to produce immobilized Friedel's salt.

In the case of the composition according to the present invention, since the organosilane compound is hydrolyzed by reacting with water to form silica, the water of the silane-based and alcohol-based solvents should be as low as possible in order to improve penetration. In addition, it is preferable to use a nonionic or anionic fluorine-based surfactant in the alkali silica to improve the reactivity and permeability with the concrete surface.

In addition, the alkali-based silica that is commercially available or in use has a very small penetration force because it rapidly bonds with calcium ions, which is the main component of concrete. Therefore, the alkali-based silica is effective for chemical stability on the surface of the concrete, but the penetration depth is about 5mm is not preferable because it can not penetrate deep into the concrete, alkali-based silica after penetrating deep into the concrete surface using the silane series of the present invention It is very desirable to use.

In addition, as a result of using various silanes and various alcohols, it is considered that there is no compound that causes problems in penetration related to concrete, and thus it is judged to have high useful value. Fire must be taken care of.

Alkali silicates are inorganic binders that are fragrance free, nonflammable, and have heat resistance. This material is used for polymer reinforcement, coating and glass surface treatment. However, when used as a repair material for polymers and fatty acids, there is a high risk of decomposition and damage of organic materials by temperature strengthening, and the bonding strength is lowered due to the heterogeneous properties of concrete. In particular, in Korea, where the four seasons are distinct, shrinkage and expansion rates are different, and in the long run, it causes the concrete to peel and loses its meaning as a repair material.

In addition, when alkali silicate is coated on the surface of the concrete structure, a coating layer having excellent bonding strength is formed and insoluble calcium silicate is formed to fill the voids of about 5mm from the surface of the concrete, thereby protecting the surface of the concrete and infiltrating deteriorated materials. To block. Therefore, the research results of the present invention confirmed that the alkali silicate included in the deterioration inhibitory composition has a very low reaction rate with calcium ions, which is the main component of concrete, and is very unlikely to penetrate into the concrete. However, when using the penetration-enhancing composition of the present invention containing a solvent and a silane series, there is no reactivity with calcium ions, and since the surface tension is very small, it can penetrate deep into the concrete, and the secondary silicate silicate and Sprinkle a solution containing water to react with water in the concrete to form nano-sized silica and alcohol by hydrolysis, filling the voids, alcohol is released into the atmosphere, and the concrete surface is rapidly formed with calcium silicate. It can provide physical and chemical protection of concrete interior and surface.

Particularly in the case of tetraethoxysilane, in the Si (CO ₂ H ₅ ) ₄ solution, Si (CO ₂ H ₅ ) ₄ is hydrolyzed to a molecule containing an OH group, and further, H ₂ O is derived from molecules containing an OH group. Then, Si passes through O, and a linked siloxane bond -Si-O-Si- is formed into a polysiloxane. Fully developed siloxane bonds result in gelation of the solution. Particles produced and dispersed in the state of the sol before becoming a gel are one-dimensional polymers, and the sol exhibits ordinary properties.

There are two types of reactions in alkoxide solutions: hydrolysis and polycondensation. In these reactions, the composition of the solution, catalyst (acid, alkali), pH, and temperature are affected, and these factors change with the progress of the reaction. The reaction process can be explained as very complicated.

Substantial reactions in the present invention are as follows.

nSi (OC ₂ H ₅ ) ₄ + (3n + 1) H ₂ O → SinO _{n + 1} (OH) _{2n + 2} + 4nC ₂ H ₅ OH

Therefore, the present inventors penetrate deep into the concrete surface when the silane-based penetration strengthening composition is applied to the surface of the concrete structure, hydrated with water contained in the alkali silicate, and gelation occurs to prevent voids in the concrete, thereby reinforcing concrete recovery and neutralization. Alkaline silicate has a very dense insoluble calcium silicate film formed by the main component of concrete reacting with calcium ion, forming a very stable protective film in acid not only inside the concrete but also on the surface. The neutralization of concrete by acid rain or external environment can be prevented, and it was confirmed that the effect of concrete reinforcement and blocking of deteriorated material is very excellent.

As described above, when repairing concrete through the composition and treatment method according to the present invention, unlike the conventional method, the concrete does not crush around damaged concrete when deterioration occurs, and penetrates deeply into the concrete structure quickly and causes hydrolysis. By forming a fine sol-gel by filling the fine pores to prevent the neutralization deep in the surface and the interior of the concrete structure and has the effect of strengthening the concrete sphere. In addition, by forming a barrier with improved strength up to the reinforcement depth of the reinforcement, there is a very excellent effect of protecting the concrete structure from harmful substances such as chloride or carbon dioxide (CO ₂ ) and consolidating the concrete structure with repairability of cracks.

Therefore, the concrete surface treatment method and the composition for two-component concrete inorganic repair agent according to the present invention are excellent in permeability, surface protection, stability, etc., civil engineering structures such as bridges, underground roadways, dams, breakwaters, and basement floors, verandas, bathhouses, It can be applied to building structures such as swimming pools, water tank reservoirs, industrial facilities such as wastewater treatment plants, and also in repairing cracked areas of concrete structures due to ground subsidence, structural stress, and external environment.

Claims (5)

On the concrete surface, Trimethylmethoxy silane, trimethylethoxy silane, dimethyldimethoxy silane, dimethyldiethoxy silane, methyltrimethoxy silane, methyltriethoxy silane, tetramethoxy silane, tetraethoxy silane, methyldimethoxy silane, methyldiethoxy Silane, dimethylethoxy silane, dimethylvinylmethoxy silane, dimethylvinylethoxy silane, methylvinyldimethoxy silane, methylvinyldiethoxy silane, diphenyldimethoxy silane, diphenyldiethoxy silane, phenyltrimethoxy silane, phenyl 4 to 60% by weight of one or two or more silane compounds selected from the group consisting of triethoxy silane, octadecyltrimethoxy silane, and octadecyltriethoxy silane, and an agent for injecting a mixture of 40 to 96% by weight of anhydrous alcohol. Stage 1; And After 5 to 240 minutes, containing 5 to 25% by weight of alkali silicate consisting of at least one silicate of sodium silicate and potassium silicate, and 0.05% by weight or less of nonionic or anionic fluorine-based or silicon-based surfactant, and distilled water 100 Spraying a mixture filled with weight percent; Concrete surface treatment method comprising a. According to claim 1, The anhydrous alcohol in the first step is one or a mixture of two or more selected from ethanol, methanol or 2-propanol How to Treat Concrete Surfaces. Trimethylmethoxy silane, trimethylethoxy silane, dimethyldimethoxy silane, dimethyldiethoxy silane, methyltrimethoxy silane, methyltriethoxy silane, tetramethoxy silane, tetraethoxy silane, methyldimethoxy silane, methyldiethoxy Silane, dimethylethoxy silane, dimethylvinylmethoxy silane, dimethylvinylethoxy silane, methylvinyldimethoxy silane, methylvinyldiethoxy silane, diphenyldimethoxy silane, diphenyldiethoxy silane, phenyltrimethoxy silane, phenyl Concrete penetration reinforcement by mixing 4 to 60% by weight of one or two or more mixtures selected from the group consisting of triethoxy silane, octadecyltrimethoxy silane, and octadecyltriethoxy silane with 40 to 96% by weight of anhydrous alcohol. An inorganic inorganic repair composition (A), Concrete deterioration inhibiting inorganic repair agent comprising 5 to 25% by weight of alkali silicate consisting of at least one silicate of sodium silicate and potassium silicate, and 100% by weight of 0.05% by weight of a nonionic or anionic fluorine- or silicone-based surfactant Comprising composition (B) Composition for two-component concrete inorganic repair agent. Trimethylmethoxy silane, trimethylethoxy silane, dimethyldimethoxy silane, dimethyldiethoxy silane, methyltrimethoxy silane, methyltriethoxy silane, tetramethoxy silane, tetraethoxy silane, methyldimethoxy silane, methyldiethoxy Silane, dimethylethoxy silane, dimethylvinylmethoxy silane, dimethylvinylethoxy silane, methylvinyldimethoxy silane, methylvinyldiethoxy silane, diphenyldimethoxy silane, diphenyldiethoxy silane, phenyltrimethoxy silane, phenyl Concrete penetration reinforcement by mixing 4 to 60% by weight of one or two or more mixtures selected from the group consisting of triethoxy silane, octadecyltrimethoxy silane, and octadecyltriethoxy silane with 40 to 96% by weight of anhydrous alcohol. Composition for sex inorganic repair agent. Concrete deterioration inhibiting inorganic repair agent comprising 5 to 25% by weight of alkali silicate consisting of at least one silicate of sodium silicate and potassium silicate, and 100% by weight of 0.05% by weight of a nonionic or anionic fluorine- or silicone-based surfactant Composition.