KR101798953B1 - Mortar composition for repairing and reinforcing concrete structure with superior property of waterproof and rust prevention, and method of repairing and reinforcing concrete structure using the same - Google Patents

Abstract

The present invention relates to a mortar composition to repair and reinforce a concrete structure with excellent waterproof and anti-corrosion performance, and a concrete structure repairing and reinforcing method using the same and, more specially, related to a concrete structure repairing and reinforcing method capable of: improving durability and bonding strength when a damaged part of a deteriorated concrete structure is repaired, to maintain a repair effect for a long term and also stably complete a repair construction in a short time, to provide excellent economic efficiency and an excellent anti-neutralization effect; reinforcing water-tightness to minimize an effect due to an external atmospheric effect, such as acid rain; and mixing a binder and a control agent at an optimal ratio to control an agglomeration speed and exhibit rapid hardening property. When a damaged part of a concrete structure is repaired by such method, excellent physical characteristics, such as bending strength, tensile strength, compressive strength, etc., excellent bonding properties with the concrete structure, excellent chemical resistance and waterproofing effect, and excellent durability against freezing/melting and salt damage are provided, a curing speed of mortar is increased, and anti-neutralization effect and waterproof effect is able to be increased. In particular, provided are advantages capable of reinforcing water-tightness to minimize an effect due to external atmospheric environment, such as acid rain, and capable of mixing the binder and the control agent at an optimal ratio to control an aggregation speed and provide rapid curing properties. Moreover, a surface protection agent with excellent bonding force with recovery mortar disposed in a lower part, and excellent properties, such as impact resistance, chemical resistance, and waterproof, anti-neutralization, anti-collision, anti-bacterial, anti-fouling, ventilation, and weather resistance properties, is used, thus providing an effect capable of maintaining repair/reinforcement effect for a long term. According to the present invention, the method comprises: a surface treatment step; an anti-rust agent coating step; a repair/reinforcement mortar composition coating step; and a surface protection agent coating step.

Description

Technical Field [0001] The present invention relates to a mortar composition for repairing and reinforcing a concrete structure having excellent waterproof performance and a method for repairing and reinforcing a concrete structure using the same }

The present invention relates to a mortar composition for concrete repair and reinforcement excellent in waterproofness and anticorrosion property, and a repair and maintenance method using the same. More particularly, the present invention relates to a mortar composition for repairing and repairing damaged parts of a deteriorated concrete structure, It is possible to achieve long-term maintenance and stable completion of repair work in a short time, thus providing excellent economic efficiency and excellent effect of preventing the neutralization of concrete. Especially, water tightness can be strengthened to minimize the influence of external atmosphere such as acid rain, To a method of repairing and reinforcing a concrete structure capable of controlling a coagulation rate and exhibiting rapidity by mixing an agent at an optimum ratio.

Reinforced concrete structures are deteriorated in durability and usability in the long term due to deterioration of structures due to salt corrosion, neutralization, alkali aggregate reaction, chemical corrosion as well as corrosion expansion of steel due to penetration of water. As the deterioration of these structures continues, there is a risk of eventual collapse of the structures, so it is necessary to continuously manage and repair them.

Since the detachment of the structure surface or the occurrence of initial defects or cracks facilitates the movement of deterioration factors and promotes the progress of deterioration, in order to secure the stability and performance of the reinforced concrete structure, And it is necessary to improve the durability performance.

Therefore, after removing the concrete part including deterioration factors such as deterioration factor such as deterioration of concrete, corroded steel, and other factors, it is necessary to fill or spray the maintenance reinforcement material to restore the original section to its original performance and shape. It is general to carry out repair by construction.

Conventional repair materials for cement mortar and polymer cement mortar have been used as repair materials for conventional repair and reinforcement. These conventional repair materials are used for the purpose of suppressing deterioration of existing structures and improving the durability of the existing structure. Since most of the focus is on improving the performance, the surface is often easily damaged again after the construction.

For example, Korean Patent Laid-Open No. 10-2006-0079447 proposes a method for producing a mortar composition by adding CSA (calcium sulfoaluminate) and a predetermined powdery binding material. However, the mortar composition prepared using the above-mentioned materials causes an increase in the unit cost of the construction due to the use of expensive Hauyene cement, and sufficient results in terms of the initial setting time and the strength were not obtained.

In addition, when the conventional repair method is applied, water and oxygen penetrate into fine gaps on the surface, so corrosion of the reinforcing bar due to oxygen progresses, deterioration of the concrete due to moisture occurs, There was a problem that construction work should be carried out frequently.

On the other hand, the surface protecting agent for protecting the surface of the concrete structure is a fluid material, which is widely applied to the surface of the structure to form a thin coat layer, and by drying over time, protects the surface of the structure and enhances aesthetics It prevents damage such as corrosion and improves durability.

These surface protective agents have conventionally been used as aqueous surface protective agents, oily surface protective agents, and enamel surface protective agents. However, they have not been effective in preventing the release of harmful components generated from concrete, and also have been used for various bacterial and fungal Prevention effect, prevention effect against pollution, and prevention effect of neutralization of inner concrete have not been widely used.

The present invention has been developed in view of the circumstances of the prior art as described above, and it is an object of the present invention to improve the durability and the adhesive strength in repairing a damaged part of a deteriorated concrete structure to maintain a repairing effect for a long time, It is possible to minimize the effect of external atmosphere such as acid rain and to control the setting speed by mixing the binder and control agent at an optimum ratio. And to provide a method of repairing and reinforcing a concrete structure that can exhibit rapid hardening.

In addition, as a surface protective agent, it has excellent adhesion with the restoration mortar and has excellent properties such as impact resistance, chemical resistance, water resistance, anti-neutralization, anti-corrosion property, We want to provide the construction method.

In order to achieve the above object,

(1) a first step of removing a deteriorated portion of a concrete structure, removing foreign matter, and arranging the surface of the deteriorated portion using high-pressure washing water;

(2) a second step of applying an alkali remover to the surface-finished concrete structure and applying a rust-preventive coating agent to the exposed reinforcing bars;

(3) a third step of applying the repair reinforcing mortar composition to the surface to which the alkali remover is applied and the rust-preventive coating agent is applied; And

(4) a fourth step of applying a surface protective agent after the repair and reinforcing mortar composition is applied,

In the third step, the mortar composition for maintenance and repair comprises 20 to 40 parts by weight of cement, 2 to 10 parts by weight of a calcium sulfoaluminate (CSA) based swelling agent, 5 to 25 parts by weight of a fine powder filler, 1 to 10 parts by weight of re- parts, water reducing agent 0.1 to 0.5 parts by weight of a reinforcing fiber 0.1 to 0.5 parts by weight of silica sand of 40 to 60 parts by weight, 0.1 ~ 3mm density 0.2 ~ 0.4 g / cm ³ silica lightweight claim 1 to 20 having an average diameter of the parts by weight of 0.1 to 10 parts by weight of an inorganic curing agent,

In the fourth step, the surface protecting agent may be prepared by mixing synthetic resin fibers having a density of 10 to 1000 g / m < ³ > to a coating liquid containing a methyl methacrylate (MMA) resin, a peroxide curing agent and an additive, Reinforcing method for a concrete structure is characterized in that a coating film is formed by using a surface protective agent obtained by mixing 30 to 300 parts by weight of an inorganic powder component with 100 parts by weight of a mixture obtained by mixing a rubber chip, an airgel, a cellulose powder and a powder component to provide.

In one embodiment of the present invention, the inorganic curing agent is a binder comprising CaO and SO _3, and a control agent comprising a mixture of Al ₂ O ₃ and Na ₃ O as a controlling agent for controlling the setting speed of the binder The binder and the control agent are preferably mixed so that the binder / control agent ranges from 1.2 to 1.8.

The inorganic curing agent may further include 1 to 10 parts by weight of a polymer powder based on 100 parts by weight of the binder and the control agent.

In one embodiment of the present invention, in the fourth step, the powder component is mixed with 30 to 50 wt% of mica having a particle diameter of 1 to 100 탆, 30 to 50 wt% of a stone powder, and 5 to 20 wt% Can be used.

Further, in one embodiment of the present invention, the inorganic powder component in the fourth step may include silica powder, alumina cement, bentonite powder, and ceramic nanoparticle mixture.

When the damaged part of the concrete structure is recovered by using the method according to the present invention, the physical properties such as the bending strength, the tensile strength and the compressive strength are excellent, the adhesion with the concrete structure is excellent, the chemical resistance and the waterproof property are excellent, Resistance to freezing and thawing and salt corrosion is also excellent and the curing speed of the mortar can be improved and the anti-neutralization effect and waterproof effect can be increased. Particularly, the water tightness can be enhanced to minimize the influence of external atmosphere such as acid rain, and the mixing speed of the binder and the control agent can be controlled at an optimal ratio, and the fastness can be exhibited.

Also, it is possible to maintain the maintenance effect for a long time by using the surface protection agent having excellent adhesion with the repair mortar formed and excellent in properties such as impact resistance, chemical resistance, waterproofness, anti-neutralization, anticorrosion, antimicrobial property, antifouling property, air permeability and weather resistance There is an effect.

Hereinafter, the present invention will be described in more detail.

The method for repairing and reinforcing a concrete structure according to the present invention proceeds in the following order. In other words,

(1) a first step of removing a deteriorated portion of a concrete structure, removing foreign matter, and arranging the surface of the deteriorated portion using high-pressure washing water;

(2) a second step of applying an alkali remover to the surface-finished concrete structure and applying a rust-preventive coating agent to the exposed reinforcing bars;

(3) a third step of applying the repair reinforcing mortar composition to the surface to which the alkali remover is applied and the rust-preventive coating agent is applied; And

(4) a fourth step of applying the surface protective agent after the repair and mortar composition is applied.

First, the deteriorated portion of the damaged concrete structure is chipped and the surface or section is trimmed until the undamaged portion comes out. That is, it is possible to remove cracks, dropouts, rebar rust, lifting and corrosion of the reinforced concrete structure caused by the aging phenomenon such as alkali aggregate reaction, sea damage, salt corrosion or neutralization (carbonation) . At this time, an electric hammer or a hand tool can be used, and a high-pressure water cleaner can be used.

Subsequently, an alkaline recovery agent is applied to the surface-finished concrete structure, and a rust-inhibitive coating agent is applied to the exposed reinforcing bars.

The alkaline recovery agent may be, for example, a silicate-based alkaline recovery agent, and more specifically, a lithium silicate-based alkaline recovery agent may be used, but is not limited thereto.

The anti-corrosive coating agent may be a ginseng base antirust agent, but is not limited thereto.

Subsequently, the alkaline recovery agent is applied to the surface to which the rust-inhibitive coating agent is applied, and the mortar composition for maintenance and reinforcement is applied by spraying or by hand application.

The mortar composition for repair and reinforcement used in the present invention comprises 20 to 40 parts by weight of cement, 2 to 10 parts by weight of a calcium sulfoaluminate (CSA) type swelling agent, 5 to 25 parts by weight of a fine powder filler, 1 to 10 parts by weight of re- parts, water reducing agent 0.1 to 0.5 parts by weight of a reinforcing fiber 0.1 to 0.5 parts by weight of silica sand of 40 to 60 parts by weight, 0.1 ~ 3mm density 0.2 ~ 0.4 g / cm ³ silica lightweight claim 1 to 20 having an average diameter of the parts by weight of 0.1 to 10 parts by weight of an inorganic curing agent

In the present invention, the cement may be ordinary portland cement, and other types of cement such as alumina cement, Auwin cement, and quick-setting cement may be used singly or in combination.

In the present invention, the calcium sulfoaluminate (CSA) type expanding agent serves to prevent shrinkage and cracking of the single-sided repair mortar and to impart early curing properties, and is preferably included in the composition in a range of 2 to 10 parts by weight.

In the present invention, the above-mentioned fine powder filler is a filler composed of a slag component, and serves to densify the structure by filling micro voids when curing the mortar composition for maintenance reinforcement, and to strengthen durability and resistance to sulfate and chloride ions. To 25 parts by weight.

In the present invention, the re-melting type powdered resin may be used for adhesion to concrete structures, prevention of penetration of water and harmful substances by filling of voids, resistance to abrasion, bending and impact, Ethylene vinyl acetate (EVA), styrene butadiene rubber (SBR), or acrylic resin may be used, and it is preferably contained in the range of about 1 to 10 parts by weight of the composition.

In the present invention, the water reducing agent serves to reduce the water-cement ratio to secure fluidity and prevent durability deterioration, and naphthalene-based, melamine-based, sulfonic acid-based, polycarboxylic acid-based water reducing agents and the like can be used. The water reducing agent is preferably contained in the composition in an amount of about 0.1 to 0.5 parts by weight.

In the present invention, the reinforcing fiber may be hydrophilic nylon or PVA fiber having a length of about 3 to 10 mm to prevent cracking and to maintain the shape of the mortar during construction. In the present invention, the reinforcing fiber is preferably included in the composition in an amount of about 0.1 to 0.5 parts by weight.

In the present invention, the silica sand serves to prevent drying shrinkage and increase the strength of the mortar, and it is preferable that the silica sand is included in the composition in a range of 40 to 60 parts by weight.

In the present invention, the silica lightweight material plays a role of reducing the density of the mortar and enhancing the freeze-thaw resistance. In the present invention, the silica lightweight material has a density of 0.2 to 0.4 g / cm ³ having an average diameter of 0.1 to 3 mm It is preferable to use expanded silica formed into a spherical shape whose interior is closed as a lightweight sieve.

In the present invention, it is preferable that the silica light weight material is included in the range of about 1 to 10 parts by weight of the whole mortar composition.

In the present invention, the inorganic curing agent provides an integral structure with the concrete matrix when the mortar composition is applied, and the cured body has high strength, durability and water resistance, and controls the setting speed to impart fastness.

That is, the inorganic curing agent comprises a binder for enhancing integration with the concrete matrix and a controlling agent for controlling the setting speed, the binder being made of CaO and SO ₃ , the controlling agent being Al ₂ O _3, and comprises a Na ₂ O. Further, it is more preferable to use a mixture of the binder and the control agent falling within the range of 1.2 to 1.8 as the binder / control agent.

In addition, in the present invention, the inorganic curing agent may further comprise a powdery polymer resin in addition to the mixture of the binder and the control agent.

The polymer powder resin is a dispersion material prepared by spray-drying a liquid resin, and is a liquid liquid resin when dispersed in water. The powdered resin dispersed in water forms an irreversible polymer film that does not dissolve in water after drying and is mixed with cement like liquid resin to improve tensile and flexural strength. The polymer powder resin may be a natural rubber-based or polyacetate-based resin, and is preferably mixed with about 1 to 10 parts by weight based on 100 parts by weight of the binder and the control agent.

In the present invention, when applying the mortar composition for repairing and reinforcing concrete structures, spray or trowel is used to apply 5 to 15 mm for primary casting, 20 to 50 mm for secondary and tertiary casting, and 5 to 15 mm for final casting And the like.

In the present invention, before applying the mortar composition for repair and reinforcement, the method may further include a step of applying a primer (primer) to the refinement target surface. In the present invention, the primer may be a generally used primer. By using a primer, the adhesion of the primer to the concrete surface to be applied can be further strengthened, and the construction can proceed more efficiently.

Then, the mortar composition for repair and reinforcement is coated on the concrete crushing site, smoothly finished and dried, and then the special surface protection agent according to the present invention is thinly coated on the surface thereof to protect the repaired surface from external conditions.

The surface protecting agent is applied by using a brush, roller, spray or the like in order to prevent the neutralization of the concrete structure and the prevention of salt damage. The surface protecting agent used in the present invention includes a methyl methacrylate (MMA) resin, a peroxide type curing agent, 30 to 300 parts by weight of an inorganic powder component are mixed with 100 parts by weight of a mixture obtained by mixing synthetic resin fibers having a density of 10 to 1000 g / m < ³ > in a coating liquid and mixing acrylic resin, rubber chip, aerogel and powder components The resulting surface-protective agent is used.

More specifically, the coating liquid containing the MMA resin comprises 78 to 86% by weight of an MMA resin, 0.5 to 5% by weight of a peroxide-based curing agent, and 10 to 20% by weight of an additive. The MMA resin may be a mixture of a low viscosity MMA resin having a viscosity of 10 to 1,000 cps and a high viscosity MMA having a viscosity of 2,000 to 20,000 cps. In this case, it is preferable that the mixing ratio is mixed at a low viscosity MMA: high viscosity MMA = 40 to 70: 30 to 60 weight ratio.

Also, a modified MMA obtained by mixing 1 to 10% by weight of a mixture of at least one selected from styrene isoprene styrene (SIS), styrene butadiene rubber (SBR), and styrene butadiene styrene (SBS) It can also be used.

In the present invention, the peroxide-based curing agent serves to initiate the polymerization reaction of the MMA resin. Examples of the curing agent include benzoyl peroxide, t-butyl peroxybenzoate, methyl ethyl ketone peroxide, cumene hydroperoxide, 5-dimethylhexyl-2,5-diperoxybenzoate, and the like. In the present invention, the peroxide-based curing agent is preferably used in the range of 0.5 to 5% by weight. When the content is less than 0.5% by weight, the polymerization initiating reaction is lowered, If it exceeds 5.0% by weight, it is difficult to control the polymerization reaction efficiently.

In the present invention, the additive may include an inorganic silane resin, a dispersant, a defoamer, an emulsifier, and the like. If the base material is concrete, cement may be added to the additive in order to strengthen adhesion with concrete.

The inorganic silane resin is a transparent liquid material composed of an aqueous colloidal nano silica and exhibits a strong alkalinity of pH 12 or more. The inorganic silane resin penetrates into the surface of a concrete or the like due to its excellent osmosis action, .

In the present invention, the emulsifier serves to easily mix water and a resin to be mixed with a coating liquid containing the MMA resin according to the present invention. As the emulsifier in the present invention, a glycerin fatty acid ester, a sorbitan fatty acid ester, or a polyglycerin fatty acid ester may be used.

The synthetic resin fiber is mixed with the coating liquid obtained above. The synthetic resin fibers may be mixed with synthetic resin fibers having a density of 10 to 1000 g / m ² , for example, nylon-based or polyester-based synthetic resin fibers may be used. Such synthetic resin fibers serve to strengthen the bonding force.

Then, an acrylic resin, a rubber chip, an airgel, a cellulose powder and a powder component are further mixed.

Specifically, it may be mixed at a ratio of 20 to 30 parts by weight of an acrylic resin, 10 to 15 parts by weight of a rubber chip, 1 to 10 parts by weight of a cellulose powder, 0.5 to 5 parts by weight of an airgel and 10 to 40 parts by weight of a powder component.

More specifically, as the acrylic resin, specifically, one or two or more kinds of copolymers selected from butyl acrylate, acrylic acid, methyl methacrylate (MMA) and 2-ethylhexyl acrylate may be used as the acrylic latex.

The rubber chip may be a natural rubber chip or a recycled rubber chip such as a waste tire. Specifically, a rubber chip having a diameter of about 0.2 to 0.8 mm may be used. The rubber chip is mixed with an acrylic resin to impart heat and dew condensation preventing effect to the coating layer, to prevent damage and lifting of the coating layer, and to absorb external impact.

The airgel may be a silica airgel powder. The powder may be a transparent nanoporous material having a particle diameter of about 10 to 2000 μm, having a density of about 0.05 to 0.1 g / cm ³ , a porosity of 90 to 99% 200 to 2000 m ² / g, and a pore volume of 2 to 10 cm ³ / g. The aerogels serve to reduce the influence of the external environment by providing a heat insulating effect due to pores existing in the particles.

The cellulose powder preferably has an average diameter of 1 to 100 mu m, and serves to adjust the viscosity of the surface protective coating liquid and improve the adhesion strength to the surface.

In the present invention, it is preferable to use a mixture of 30 to 50% by weight of mica having a particle diameter of 1 to 100 μm, 30 to 50% by weight of an abrasive, and 5 to 20% by weight of titanium oxide.

The mica is used in the coating film to strengthen the elasticity, elongation and adhesion strength.

The above-mentioned stone powder plays a role of strengthening abrasion resistance, slip resistance, adhesion and the like.

The titanium oxide serves to improve the heat insulating performance by suppressing the transmission of the radiant light, and blocks ultraviolet rays and imparts antifouling properties.

The inorganic powder component is further mixed with the thus obtained mixture to obtain a surface protective agent. The inorganic powder component is preferably used in a range of about 30 to 300 parts by weight based on 100 parts by weight of the mixture.

Specifically, the inorganic powder component is preferably composed of silica powder, alumina cement and bentonite powder.

More specifically, the inorganic powder component preferably comprises 40 to 70 parts by weight of silica powder, 1 to 5 parts by weight of alumina powder, and 0.5 to 5 parts by weight of bentonite powder.

The silica powder serves to promote curing of the coating film, and it is preferable to use a powder having a particle diameter of about 0.05 to 0.1 mm.

The alumina powder serves to reduce drying shrinkage and it is preferable to use a powder having a particle size of about 0.05 to 2.0 mm.

The bentonite powder plays a role of absorbing water and moisture and adjusting the viscosity, and preferably has a particle diameter of about 0.05 to 1.0 mm.

The surface protective agent thus obtained is coated on the surface to which the repair and reinforcement mortar composition is applied and coated to finish the final work. With the above-described operation, the bonding force is increased, the peeling phenomenon is prevented, and the waterproof effect is increased. In addition, water resistance is exhibited, water absorption effect is low and excellent waterproof effect is exhibited, and cracking of concrete caused by freezing and thawing is suppressed.

The surface protective agent according to the present invention is excellent in weatherability, surface strength and water resistance by coating only once, but it is preferable to repaint 2-3 times in order to exhibit its function optimally. In the present invention, it is preferable that the surface protecting agent is applied to the cured surface of the mortar composition for maintenance and repair at 20 to 200 g / m ² , and the coating thickness is applied at a thickness of 50 to 300 μm before the drying.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by the following examples.

[Example]

Production Example 1 (Mortar composition production)

30 parts by weight of portland cement, 3 parts by weight of calcium sulfoaluminate (CSA) based swelling agent, 15 parts by weight of fine powder filler (slag), 2 parts by weight of re-oiled powder resin, 0.2 parts by weight of water reducing agent, 0.3 parts by weight of reinforcing fiber 50 parts by weight of silica sand, 5 parts by weight of a silica lightweight having an average diameter of 0.2 to 0.4 g / cm ³ having an average diameter of 0.1 to 3 mm and 0.8 parts by weight of an inorganic curing agent were mixed with a predetermined amount of water to prepare a mortar composition. Wherein the inorganic curing agent comprises a binder consisting of CaO and SO ₃ and a control agent comprising a mixture of Al ₂ O ₃ and Na ₂ O as a controlling agent for controlling the setting speed of the binder, The mixing ratio of the control agent was used in the range of binder (CaO + SO ₃ ) / control agent (Al ₂ O ₃ + Na ₂ O) = 1.5.

Comparative Preparation Example 1 (Mortar Composition Preparation)

A mortar composition was prepared in the same manner as in Preparation Example 1 except that the silica lightweight agent was used.

Comparative Production Example 2 (Mortar composition production)

The mortar composition was prepared in the same manner as in Preparation Example 1 except that the inorganic curing agent was not used.

Comparative Preparation Example 3 (Preparation of mortar composition)

The mortar composition was prepared in the same manner as in Preparation Example 1 except that the silica lightweight agent and the inorganic hardening agent were not used.

Performance evaluation of mortar

1. Bending strength, compressive strength, tensile strength, bond strength and volume change rate test

The flexural strength, compressive strength, tensile strength, volume change rate and adhesion strength of the mortar composition prepared according to Preparation Example 1 and Comparative Preparation Examples 1 to 3 were measured.

The flexural strength, compressive strength, tensile strength, and adhesion strength were measured according to the standard of KS F 4042-02 after 28 days of application of the concrete repair agent. The volume change rate was such that the volume of the mortar composition after 28 days of application was changed from 0 ° C to 35 ° C And the degree of volumetric change was measured daily by varying the temperature. The results are shown in Table 1 below.

Sample Flexural strength
(N / mm < 2 & Compressive strength
(N / mm < 2 & The tensile strength
(N / mm < 2 & Bond strength
(MPa) Volume change rate
(%) Production Example 1 21.0 62.8 6.0 1.7 0.0001 Comparative Preparation Example 1 17.2 50.0 4.0 1.0 0.0005 Comparative Production Example 2 15.5 35.5 3.5 0.5 0.0009 Comparative Production Example 3 10.6 40.0 4.0 1.2 0.0012

Referring to Table 1, the mortar composition for repair and reinforcement according to the present invention shows that the mortar composition of the present invention is superior in strength and adhesion performance compared to conventional materials.

2. Waterproof and chemical resistance test

The waterproofing and chemical resistance of the mortar composition for repair and reinforcement prepared according to Preparation Example 1 and Comparative Preparation Examples 1 to 3 were measured.

The waterproof property was evaluated by coating the mortar composition on the concrete structure to a thickness of 1 cm and installing a cylindrical water tank on the mortar composition layer to check the permeation of water for 6 months.

The chemical resistance was evaluated by treating the mortar composition layer having a salt concentration of 35 ‰ and the sulfuric acid solution having a concentration of 2% on the mortar composition layer after 28 days of curing on the concrete structure for 1 hour each day, And was confirmed for 60 days.

The results are shown in Table 2 below.

Sample Water resistance test
(month) Chemical resistance test (days) Brine Sulfuric acid solution Production Example 1 - - 66 Comparative Preparation Example 1 One 20 26 Comparative Production Example 2 One 25 25 Comparative Production Example 3 2 32 19

As shown in Table 2, in the case of Production Example 1, moisture was not penetrated at all for 6 months, whereas in Comparative Production Examples 1 to 7, it was confirmed that moisture penetrated after 1 to 2 months. This is interpreted as a result of showing the excellent waterproof performance of the mortar composition for repair and reinforcement according to the present invention.

In Table 2, it can be seen that no surface damage was caused by the brine treated for 60 days in Production Example 1, and no surface damage was observed 60 days before the treatment with sulfuric acid solution. On the other hand, in Comparative Preparation Examples 1 to 3, surface damage occurred 20 to 40 days after the saline treatment, and surface damage was observed within 10 to 30 days when the sulfuric acid solution was treated.

This is interpreted as a result of supporting the excellent chemical resistance of the mortar composition according to the present invention.

3. Freeze-thaw resistance, crack resistance and dry shrink resistance

The freeze-thaw resistance, crack resistance and shrinkage resistance of the mortar composition prepared according to Preparation Example 1 and Comparative Preparation Examples 1 to 3 were measured.

The freeze-thaw resistance was tested by the freeze-thaw resistance test according to KS F 2456.

Crack resistance was tested according to AASHTO PP34-98.

Dry shrinkage resistance was tested according to KS F 2424.

The results are shown in Table 3.

Sample Freeze-thaw resistance (%) Crack resistance Dry shrinkage resistance Reference value: 80% or more Reference value: No crack up to 56 days Reference value: 0.15 or less Production Example 1 98 No crack 0.01 Comparative Preparation Example 1 88 No crack 0.02 Comparative Production Example 2 87 No crack 0.03 Comparative Production Example 3 82 No crack 0.03

Table 3 shows that the mortar composition of Production Example 1 according to the present invention is superior to the comparative preparation examples in terms of freeze-thaw resistance, crack resistance and drying shrinkage resistance.

(Production Example 2) Production of surface protective agent

Then a solution of methyl methacrylate (MMA) resin, 82 parts by weight benzoyl peroxide 2.0 parts by weight of various additives mixture 16 parts by weight mixed to create a coating solution portion polyester synthetic resin fiber here (density 100 g / m ³⁾ , 30 parts by weight of an acrylic resin, 15 parts by weight of a rubber chip, 5 parts by weight of an airgel, 5 parts by weight of a cellulose powder and 30 parts by weight of a powder. At this time, the powder component used was a mixture of 40 wt% of mica having a particle diameter of about 20 mu m, 50 wt% of a stone powder, and 10 wt% of titanium oxide. The MMA resin was prepared by mixing a mixture of a low viscosity MMA resin having a viscosity of about 100 cps and a high viscosity MMA having a viscosity of about 9,000 cps at a weight ratio of 50:50. 100 parts by weight of the obtained mixture and 50 parts by weight of inorganic powder components were mixed to prepare a surface protective agent. At this time, the inorganic powder component was mixed with silica powder, alumina cement and bentonite powder in a ratio of 50: 3: 3 parts by weight, respectively.

4. Functional evaluation

The functionality of the special functional surface protective agent obtained in Preparation Example 2 was evaluated by the following evaluation method.

1) Antifungal test

ASTMG-21. The fungal strains used were Aapergillus Aspergillus niger ATCC9642 , Penicillium pinophilum ATCC11797 , Chaetomium globosum Spores such as ATCC6205 were collected and used as mixed strains. The size of the specimen used was 20 × 30 × 3 mm. After 8 weeks, the antifungal test showed no fungal growth on the surface-protective agent.

2) Antibacterial test

The antibacterial test was carried out by the KICM-FIR-1002 method. The fungi used in this test were Escherichia coli 25922 and Pseudomonas aeruginosa ATCC 15442 was used, and the size of the specimen used was 20 × 30 × 3 mm. The surface protective agent according to the present invention was used as Escherichia coli 25922 ) and Pseudomonas aeruginosa ATCC 15442 ). As a result, the bacterial counts of E. coli and BLANK increased after 24 hours, and the bacterial counts after 24 hours decreased by 98.0 ~ 99.0%. In the case of Pseudomonas aeruginosa, BLANK increased after 24 hours, and the surface protective agent of the present invention showed a decrease in bacterial count after 24 hours and a reduction rate of 52% to 55%.

From the above results, it can be seen that when the repair and reinforcement method of the concrete structure according to the present invention is used, the effects of adhesion, durability, weather resistance, waterproofness, freezing and thawing resistance and the like are excellent, and concomitant effects have.

Claims (5)

(1) a first step of removing a deteriorated portion of a concrete structure, removing foreign matter, and arranging the surface of the deteriorated portion using high-pressure washing water;
(2) a second step of applying an alkali remover to the surface-finished concrete structure and applying a rust-preventive coating agent to the exposed reinforcing bars;
(3) a third step of applying the repair reinforcing mortar composition to the surface to which the alkali remover is applied and the rust-preventive coating agent is applied; And
(4) a fourth step of applying a surface protective agent after the repair and reinforcing mortar composition is applied,
In the third step, the mortar composition for maintenance and repair comprises 20 to 40 parts by weight of cement, 2 to 10 parts by weight of a calcium sulfoaluminate (CSA) based swelling agent, 5 to 25 parts by weight of a fine powder filler, 1 to 10 parts by weight of re- parts, water reducing agent 0.1 to 0.5 parts by weight of a reinforcing fiber 0.1 to 0.5 parts by weight of silica sand of 40 to 60 parts by weight, 0.1 ~ 3mm density 0.2 ~ 0.4 g / cm ³ silica lightweight claim 1 to 20 having an average diameter of the parts by weight of 0.1 to 10 parts by weight of an inorganic curing agent,
In the fourth step, the surface protecting agent may be prepared by mixing synthetic resin fibers having a density of 10 to 1000 g / m < ³ > to a coating liquid containing a methyl methacrylate (MMA) resin, a peroxide curing agent and an additive, Wherein a coating film is formed by using a surface protective agent obtained by mixing 30 to 300 parts by weight of an inorganic powder component with 100 parts by weight of a mixture obtained by mixing rubber chips, cellulose powder, aerogels and powder components.
The inorganic curing agent according to claim 1, wherein the inorganic curing agent comprises a binder composed of CaO and SO ₃ and a control agent composed of a mixture of Al ₂ O ₃ and Na ₂ O as a control agent for controlling the setting speed of the binder, Wherein the mixing ratio of the binder and the control agent falls within the range of 1.2 to 1.8 as the binder / control agent.
[3] The method of claim 2, wherein the inorganic curing agent further comprises 1 to 10 parts by weight of polymer powder based on 100 parts by weight of the binder and the control agent.
[3] The method according to claim 1, wherein in the fourth step, the powder component is a mixture of 30 to 50 wt% of mica having a particle diameter of 1 to 100 mu m, 30 to 50 wt% of a stone powder, and 5 to 20 wt% Repair and Rehabilitation Method of Concrete Structures.
The method of claim 1, wherein in the fourth step, the inorganic powder component comprises silica powder, alumina cement, and bentonite powder.