KR20020036930A - Permeable inorganic repair material composition of concrete building and its manufacturing method - Google Patents

Abstract

PURPOSE: A permeable inorganic repairing material composition comprising alkali-based silicate, TiO2-sol, silica-sol and permeable surfactant is provided to protect concrete construction resulting from waterproofing and rust prevention, and repair cracking and water leakage parts of construction without crushing. CONSTITUTION: The permeable inorganic repairing material composition comprises 10-35wt.% of sodium silicate with a SiO2/Na2O mole ratio of 3.4 or more, 2.5-22wt.% of lithium polysilicate, 20-30wt.% of colloidal silica with 5-20 nanometer size, 0.1-1.5wt.% of TiO2 sol, 0.05-0.35wt.% of permeable surfactant based on non-ionic or anionic fluoride, and optionally anti-gelation agent.

Description

Permeable inorganic repair material composition for concrete building and its manufacturing method {.}

The present invention relates to the permeable condensation inorganic repair materials of concrete building structures, and more particularly, it can be applied to the places where there is a high probability of leakage, such as underground floors, verandas, bathrooms, swimming pools, water tank reservoirs, wastewater treatment plants, In addition, the present invention relates to a permeable inorganic water-retaining material for concrete structures that can be applied to repairing cracks in buildings due to ground subsidence, structural stress, and external environment. The general repair method can be largely classified into surface coating method, injection method, and filling method.

In the case of the surface coating method, the materials used may be slightly different depending on whether the construction structure is large or small, but most repair materials use polymer materials or organic acids. When these materials are used, the shrinkage expansion ratio with the concrete is large and hardens with time, causing peeling (lifting) and having a problem of being easily broken by an impact. These materials are used to protect against deterioration factors of the structure rather than to improve the durability of the degraded concrete.

In the case of the crack injection method, the crack injection material is epoxy synthetic resin, which is most commonly used because of its small shrinkage and early strength, and excellent adhesion.However, crack cracking occurs after crack repair due to very different elastic modulus and shrinkage expansion rate. Has a problem.

In the case of the filling method, an epoxy mortar or an acrylic mortar is used as the 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 establish the chemical treatment technology for each deterioration factor such as neutralization, salt damage, east sea, chemical corrosion, etc. Since inorganic materials are used together, integration with the mother may be problematic.

Accordingly, an object of the present invention is to overcome the disadvantages of the conventional surface coating method, injection method, filling method used in the existing and to provide a permeable inorganic water-based repair material that can protect the waterproof and concrete while restoring the performance of the degraded concrete performance It is.

In order to achieve the above object, the composition of the permeable inorganic repair material of the concrete structure of the present invention has a SiO ₂ / Na ₂ O Mole ratio (wt%) of 10% by weight to 35% by weight of sodium silicate of 3.4 or more, and 22% by weight to 2.5% by weight of Lithium polysilicate, 30% by weight to 20% by weight of colloidal silica having a size of 5 to 20 nm, 0.1% to 1.5% by weight of TiO ₂ sol, and 0.05% to 0.35% by weight of permeability It is characterized by containing a nonionic or anionic fluorine-type surfactant.

In addition, the method for producing a permeable inorganic repair material composition of the concrete structure of the present invention is 10 wt% to 35% wt% SiO ₂ / Na ₂ O Mole ratio (wt%) of sodium silicate of 3.4 or more, 22 wt% to 2.5 wt% % Lithium polysilicate, 30% to 20% by weight of Colloidal silica having a size of 5 to 20 nm, 0.1% to 1.5% by weight of TiO ₂ sol,%, 0.05% to 0.35% by weight It is characterized by equally mixing permeable nonionic or anionic fluorine-based surfactants.

1 is a spectrum of an X-ray diffractometer appearing on the surface of a building structure before treatment with the penetrating inorganic repair material of the present invention.

2 is a spectrum of an X-ray diffractometer after treatment of the permeable inorganic repair material of the present invention on the building structure surface.

3 is an electron micrograph showing that the net-work is formed on the concrete surface when the permeable inorganic repair material of the present invention is applied to the building structure surface.

The purpose of the present invention described above is to break the condensation part in order to prevent the deterioration of the performance of the surrounding buildings due to the concrete crushing during construction to repair the heterogeneous material due to the polymer or fatty acid used as a repair material and to repair the building structure. Consists of alkali-based silicate, TiO ₂ -sol, Silica-sol and permeable surfactant that can form net work by gelation of inorganic oxide film by using inorganic repairing material of the present invention having similar expansion coefficient with concrete on concrete surface Is achieved by the concrete inorganic repair materials.

Hereinafter, the present invention will be described in detail.

Example 1

10% by weight of sodium silicate with SiO ₂ / Na ₂ O Mole ratio (wt%) of 3.4 or more

Lithium polysilicate 22% by weight

Colloidal silica (5 nm) 30 wt%

TiO ₂ -sol 0.1 wt%

Permeable Fluorine-Based Surfactant 0.05% by weight

The components were mixed evenly in the air to prepare the permeable inorganic repair material for the concrete structure of the present invention. In order to prepare the permeable inorganic water-retaining material of the concrete structure of the present invention containing such a component, the physical property test (penetration thickness, water absorption power, chlorine ion penetration power, chemical resistance) was carried out according to the method described below. It measured, compared, and evaluated.

Example 2

35% by weight of sodium silicate with SiO ₂ / Na ₂ O Mole ratio (wt%) of 3.4 or more

Lithium polysilicate 2.5 wt%

Colloidal silica (5 nm) 10% by weight

TiO ₂ -sol 1.5 wt%

Permeable Fluorinated Surfactant 0.35 wt%

The components were mixed evenly in the air to prepare the permeable inorganic repair material for the concrete structure of the present invention. In order to prepare the permeable inorganic water-retaining materials for concrete structures of the present invention containing such components, physical properties tests (penetration thickness, water absorption power, chlorine ion penetration power, chemical resistance) were carried out according to the method described below. It measured, compared, and evaluated.

Example 3

10% by weight of sodium silicate with a SiO ₂ / Na ₂ O Mole ratio (wt%) of at least 3.7

Lithium polysilicate 22% by weight

Colloidal silica (5 nm) 30 wt%

TiO ₂ -sol 0.1 wt%

Permeable Fluorine-Based Surfactant 0.05% by weight

The components were mixed evenly in the air to prepare the permeable inorganic repair material for the concrete structure of the present invention. In order to prepare the permeable inorganic water-retaining materials for concrete structures of the present invention containing such components, physical properties tests (penetration thickness, water absorption power, chlorine ion penetration power, chemical resistance) were carried out according to the method described below. It measured, compared, and evaluated.

Example 4

35% by weight of sodium silicate with SiO ₂ / Na ₂ O Mole ratio (wt%) of at least 3.7

Lithium polysilicate 2.5 wt%

Colloidal silica (20 nm) 10 wt%

TiO ₂ -sol 1.5 wt%

Permeable Fluorinated Surfactant 0.35 wt%

The components were mixed evenly in the air to prepare the permeable inorganic repair material for the concrete structure of the present invention. In order to prepare the permeable inorganic water-retaining materials for concrete structures of the present invention containing such components, physical properties tests (penetration thickness, water absorption power, chlorine ion penetration power, chemical resistance) were carried out according to the method described below. It measured, compared, and evaluated.

Example 5

20% by weight of sodium silicate with SiO ₂ / Na ₂ O Mole ratio (wt%) of 3.4 or more

Lithium polysilicate 2.5 wt%

Colloidal silica (20 nm) 10 wt%

TiO ₂ -sol 1.5 wt%

Permeable Fluorinated Surfactant 0.35 wt%

The components were mixed evenly in the air to prepare the permeable inorganic repair material for the concrete structure of the present invention. In order to prepare the permeable inorganic water-retaining materials for concrete structures of the present invention containing such components, physical properties tests (penetration thickness, water absorption power, chlorine ion penetration power, chemical resistance) were carried out according to the method described below. It measured, compared, and evaluated.

In the above embodiment, if the pH is considerably high, colloidal silica has a high probability of generating gelation. Therefore, it is advantageous to prevent gelation by adding a gelation inhibitor or by rapid addition or stirring, and preferably lower the pH as much as possible. It is preferable to use a nonionic or anionic fluorine-based surfactant to improve the reactivity and permeability with the concrete surface.

In addition, if the SiO ₂ / Na ₂ O Mole ratio (wt%) of 3.4 or more sodium silicate is more than 35% by weight, the viscosity is significantly increased, so even though the permeable fluorine-based surfactant is added, the penetration into the surface of the concrete structure is insufficient. It is not preferable, and if it is 10 wt% or less, the penetration force is good because there is no viscosity, but it is not preferable because the reactivity with the concrete surface is low.

In addition, colloidal silca is preferable to use as small particles as possible, but it is not preferable because gelation may be promoted when the average particle size is 5 nm or less.

Alkali-based silicates are fragrance-free, non-flammable, heat-resistant inorganic binders. 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 matters due to temperature strengthening, and the bonding strength decreases due to the heterogeneous properties of concrete. It causes peeling and loses the meaning of repairing material.

Therefore, the present inventors confirmed that when alkali-silicate is coated on the surface of the concrete structure, an insoluble calcium silicate is formed while the coating layer having excellent bonding strength is formed to fill the pores of the concrete, thereby protecting the waterproof role and the surface of the concrete. .

Silica-sol is a non-slip and additive of paper because of the large surface area of particles. It is used in a wide range of applications such as wetting effect on hydrophobic properties of vinyl and wax and as an effective precipitant for cationic starch. Silica-sol forms net-work by gelation according to drying process, pH (pH) change and temperature change.

Therefore, the present inventors form a very dense silica film when the silica structure is coated and then dried on the surface of the concrete structure to form a very stable protective film against acid to prevent neutralization of concrete due to acid rain or external environment. Confirmed that it can.

Test piece production

In order to test the repair materials, concrete mixing was carried out according to the method of MTC-M1-79, and the mixed concrete was composed of 15 small slabs (150 × 150 × 150 cm) and 9 large slabs (300 × 300 × 300 cm). After the mold was made and filled by ASTM C192 method, the test specimen including the margin was prepared. All samples were cured for 14 days and compared with those treated with the permeable inorganic repair materials of the present invention, including blank samples. The experimental result made the result of Examples 1-5 the average value.

Average Penetration Thickness Test of Permeable Repair Materials

The solidified 150 × 150 × 150 mm slabs for 14 days were dried under laboratory conditions, and the repair agent of the present invention was immersed in the cured specimen for 14 days for 1 minute. It was made. In this case, the average penetration thickness is 14.3 mm in the case of the blank sample, and the penetration thickness of the present invention is 16.5 mm, which improves the ability of the repairing material because the penetration of the fine crack of the building structure is good and prevents voids.

Average water absorption test

Cured and solidified slabs of 150 × 150 × 150 mm for 14 days were dried under laboratory conditions and lightly sandblasted to remove residual material on the surface of the specimens cured for 14 days. In the case of the specimen of the present invention, the one prepared in Example was coated on the surface once, and the specimen of the blank was completely dried until there was no mass change by temperature heating in an oven of 110 土 5 ℃ without coating. It was then cooled to room temperature in a tessellator. Samples coated with the repair material of the present invention including the test sample on the surface of the specimen were immersed in distilled water for 48 hours, then taken out, wiped with a cloth and weighed. In the case of the test sample, the water absorption was 4.28%, and in the case of the specimen coated with the repairing material of the present invention, the average was 2.17%. This can be explained by the fact that the net-work is formed on the surface of the building structure, resulting in a waterproof effect.

Chlorine Ion Penetration Test

In order to check the chlorine ion permeability, 300 × 300 × 75 mm specimens were prepared, and the coating material of the present invention was coated and uncoated once, and the specimen was immersed in 3% NaCl solution for 14 days. The concentration of chlorine ions was checked according to the thickness. The pretreatment of the sample was carried out by ASTM C114, the analysis of chlorine ions was carried out by ASTM D512, the average chlorine ion concentration value was calculated by subtracting the background value. Table 1 shows the concentration of water-soluble chlorine ions.

As a result of comparing the coating material of the present invention with the one-time coating and the uncoated test sample, the chlorine ion penetration rate in the concrete is very low. The main component of rebar is Fe. Fe is very reactive with chlorine ions. In other words, when using chlorine ion-containing sea sand, the reinforcing steel to increase the tensile strength of the building structure reacts with the chlorine ion to corrode with ferric chloride or iron oxide. As the steel is corroded, the steel reinforces the cracking of the concrete due to the expansion force due to oxide formation. Therefore, when comparing the chlorine ion penetration force of the repair material of the present invention can reduce the corrosion of concrete which is the most important pillar of the building structure.

Chemical resistance test

Coating of the repair agent of the present invention on the concrete surface and uncoated was carried out by the ASTM 1308 Spot Test Open method to confirm the resistance to various chemicals. 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. Subject chemicals were tested against HCl, H ₂ SO ₄ , NaOH, NH ₄ OH, and lead-free gasoline. Resistance to chemicals is shown in Table 2.

Comparing the coating with the permeable inorganic water-retaining material of the present invention with respect to chemical resistance showed similar results in the alkaline solution, but showed a big difference from the uncoated in the acid solution. Acceleration of air pollution caused by modern industrial development causes acid rain. Acid rain not only rapidly weakens the structure of concrete but also causes shortening of life due to corrosion and neutralization of steel. When the repairing material of the present invention is coated, it can play a big role in protecting the building structure by confirming that even a strong acid solution does not cause a bad result.

Organic matter decomposition test by photocatalyst

TiO ₂ -sol is an inorganic oxide used as an inorganic filler in photocatalysts and polymers. Photocatalyst is TiO ₂ having anatase structure and used to remove sunscreen or environmental pollutants in cosmetics with large nm size in order to perform photocatalytic role smoothly.

Therefore, the inventor mixed the surface of the concrete structure with TiO ₂ -sol of 15 nm size using hydrolysis using TTIP (Tetratitanium Isopropoxide) with the water-retaining material of the present invention, and then coated the concrete surface once and coated 1% on it. When the PVA (polyvinyl alchol) was evenly sprayed and left in the sun for one week, it was confirmed that foreign substances were easily removed from the surface coated with the photocatalyst than the uncoated surface. This is effective to clean the surface of the concrete by the adhesion of foreign substances contained in the atmosphere.

According to the existing method of cracking for repairing, it takes a lot of labor and time by crushing to fill the repair material by crushing, and the building structure is more vulnerable due to the surrounding microcracks due to vibration and shock during the crushing process. Can lose. As described above, according to the present invention, the permeable inorganic repair material composition of 10% by weight to 35% by weight of SiO ₂ / Na ₂ O Mole ratio (wt%) is 3.4% or more sodium silicate, 22% by weight to 2.5% by weight Lithium polysilicate, Colloidal silica having a size of 5 to 20 nm from 30% to 20% by weight, 0.1% to 1.5% by weight of TiO ₂ 0-sol, and 0.05% to 0.35% by weight of a permeable interface Since the active agent is contained, it is very effective that the colloidal silica and alkali silicate can easily penetrate the concrete structure and be integrated with the concrete structure without breaking the condensation. There is.

Claims (3)

SiO ₂ / Na ₂ O Mole ratio (wt%) of 10% to 35% by weight is at least 3.4 sodium silicate, 22% to 2.5% by weight of Lithium polysilicate, and 30% to 20% by weight of 5 A colloidal silica having a size of 20 nm, 0.1 wt% to 1.5 wt% of TiO ₂ sol, and 0.05 wt% to 0.35 wt% of a permeable surfactant are uniformly mixed. Manufacturing method. A permeable inorganic repair material composition of a concrete structure prepared by the method of claim 1. A permeable inorganic water-retaining material, wherein the permeable inorganic water-retaining material of the concrete structure manufactured by the method of claim 1 is applied to the surface of the concrete structure without crushing the condensation.