KR102087707B1 - Method of repairing and reinforcing cross-section of concrete structure by self healing using calcium hydrate solution, eco-friendly nano bubble water of carbon dioxide and mortar composition for repairment - Google Patents

Abstract

The present invention relates to a method of repairing and reinforcing a cross-section of a concrete structure and, more specifically, to a method of repairing and reinforcing a cross-section of a concrete structure, which forms a calcium carbonate crystal into deep portions in cracks of the structure without using organic materials to restore concrete in an original state, thereby enabling self-healing. Therefore, the method of repairing and reinforcing a cross-section of a concrete structure can prevent a problem in case of use of the organic materials, improve durability by state restoration of raw materials of the structure, extend a lifespan, and increase repairing and reinforcing effects.

Description

Method of repairing and reinforcing cross-section of concrete structure by self healing using calcium hydrate solution, eco-friendly nano bubble water of carbon dioxide and mortar composition for repairment}

The present invention relates to a method of repairing and reinforcing a section of a concrete structure, and more specifically, in repairing and reinforcing a concrete structure, without using an organic material, forming calcium carbonate crystals deep into the cracks of the structure to restore the original state of the concrete. In addition, it is possible to self-healing, thereby preventing problems when using organic materials, while at the same time improving the durability by restoring the condition of the raw materials of the structure and extending the life and repairing and strengthening the cross section of the concrete structure that can increase the effect of reinforcing. It's about the construction method.

In recent years, for the effective response to the NIMBY phenomenon internationally and for the reduction of CO ₂ emissions under the strong regulations of international climate change through the Basel Convention (the Convention on the Movement and Disposal of Wastes), the construction of new structures Rather, focusing on proper maintenance through repair and reinforcement of existing structures, the importance of developing environmentally-reduced repair and reinforcement methods aimed at extending the durability of concrete structures is increasing.

In addition, in order to prevent global warming, reduction of CO ₂ gas emissions is considered to be a key task imposed on the entire industry, and about 40% of total CO ₂ gas emissions were found to be due to construction activities of civil engineering structures. And the part related to the production of concrete also accounts for about 5% or more, so it is inevitable to reduce CO ₂ gas emissions in the construction industry.

On the other hand, after the collapse of Seongsu Bridge in 1994, the 『Special Act on the Safety Management of Facilities』 was enacted in January 1995, and the market size of the facility maintenance business (1995) increased from 540 billion won a year to 1 trillion won in 2001, 2 in 2007 The trillion won, in 2013, has surged to 3.5 trillion won, and the number of maintenance companies has increased rapidly to 292% with 1600 in 2003 and 4669 in 2013. The reason for this is because the maintenance investment portion of major countries is about 21-57%, while Korea is very low at about 8.0%, and the maintenance market for facilities is expected to grow rapidly in the future. In addition, as the national support policy for vitalizing the facility maintenance business, the `` Basic Plan for Safety and Maintenance of Facilities '' was established and implemented until the 3rd (2013-2017) plan.In particular, the 3rd plan converged in the field of facility maintenance reinforcement. The development of advanced maintenance technology through the introduction of technology and advanced technology is emphasized. On the other hand, in the case of apartments, it is expected that the reinforcing and reinforcement market of reinforced concrete structures will expand further and become a new growth engine for the construction industry as the “Vertical Expansion Remodeling” Act passes in the existing reconstruction concept.

Reinforced concrete structures are generally durable and can maintain safety or landscape without deterioration for more than 100 years. However, in addition to cracks due to dry shrinkage on the design and materials, construction side, lack of concrete coating thickness, and poor compaction, carbonization, salt damage, copper sea, alkali aggregate reaction, sulfate erosion, etc. Large and small cracks are generated and advanced in concrete, and eventually deterioration of concrete peeling and delamination due to corrosion of reinforcing bars is accelerated, resulting in loss of safety of concrete structures. Therefore, since cracks are ultimately generated and advanced due to various deterioration phenomena occurring in the reinforced concrete structure, the cause of cracking and crack width and depth for each deterioration phenomenon are accurately diagnosed, and the optimal repair and reinforcement method suitable for this It is very important to apply, and in particular, it is very important to develop a systematic method to fundamentally eliminate the cause of deterioration in order to prevent re-deterioration after maintenance reinforcement.

In general, the amount of organic materials (polymer materials such as epoxy resins) that are typically used to reinforce and repair cracks in concrete structures is limited in small amounts. It is in a very limited state. Here, the organic polymer material including the epoxy resin system has a high probability of causing the following problems in the structure.

First, most organic polymer materials are softened and deformed by heat, and there is a high possibility that a phenomenon in which the property changes and performances are deteriorated.

Second, the organic polymer material melts and burns with high heat from fire, and generates harmful gases.

Third, it is unfavorable to secure the durability of the structure due to differences in thermal expansion coefficients of materials different from the reinforced concrete structure. (Comparison of thermal expansion coefficient for each material-Concrete: 10 × 10 ^-6 , Reinforcing bars: 12 × 10 ^-6 , Epoxy resin: 45-65 × 10 ^-6 )

Fourth, the organic polymer material may be deteriorated in physical properties due to deformation of the internal structure over a long period of time.

In general, securing the safety and usability among the required performance of the concrete structure for civil construction becomes an important evaluation index for this structure, and the required performance is required until the structure is dismantled after the minimum life of the building (about 20 years or more). It must be maintained continuously. In particular, it is absolutely necessary to satisfy these requirements for structures that are required to secure fire resistance and durability. Therefore, in order to satisfy this required performance, the selection and construction of materials and appropriate repair and reinforcement methods considering random items such as fire and endurance are important evaluation indicators.

Meanwhile, Neville, AM Properties of Concrete ; Person Education Limited: London, UK, 1995; p. 328., Sanjun, MA Effectiveness of crack control at early age on the corrosion of steel bars in low modulus sisal and coconut fiber-reinforced mortars. Cem. Concr. Res. 1998, 28 , 555-565., Jacobsen, S. SEM Observations of the microstructure of frost deteriorated and self-healed concrete. Cem. Concr. Res. 1995, 25 , In the papers such as 1781-1790, a part of a crack in a concrete is cracked under rehydration of cement particles and precipitation of CaCO ₃ in a part of the crack of concrete, especially when the crack width is small, that is, magnetic It was confirmed that there is a healing phenomenon. This self-healing mechanism is due to the reaction of calcium ions (Ca2 +) in concrete with carbonate ions (CO32-) dissolved in water, resulting in the formation of calcium carbonate, which is poorly soluble in water. The papers report that the phenomenon is found in cracks less than 0.1 mm.

However, the theory presented in the above papers is only that some cracks are repaired by the reaction of calcium ions present in the cement itself and carbonate ions supplied from the outside, but it is considered that the original state of concrete is restored by such repair. it's difficult. Because the self-healing according to the existing theory is mainly due to the formation of calcium carbonate at the crack inlet, the deep part inside the crack still remains void and the healing of this part has not been done, so the deterioration proceeds to the internal direction. Because it can't be stopped.

Therefore, there is a limitation in fundamentally solving the problem of weakening of concrete structures and shortening of life by the method suggested in the existing studies.

[Related Prior Art Literature]

1. Republic of Korea Registered Patent No. 10-1882787

2. Korean Registered Patent No. 10-1907917

3. Republic of Korea Patent Publication No. 10-2006-0079447

The present invention was developed in consideration of the situation of the prior art as described above, in repairing and reinforcing the deteriorated concrete structure, by filling the micro-crack portion of the concrete with calcium carbonate to fundamentally heal the defects of the concrete structural concrete To strengthen the lifespan, increase the waterproof effect by densifying the pores of the concrete, while strengthening the anti-salt property in the case of coastal or offshore structures, and improving the acid resistance to protect the concrete, especially deep inside the crack area. It is intended to provide a technique to maximize the repair and reinforcement effect by reinforcing the durability of the structure and extending the life of the structure by restoring the original state of the concrete by filling it with calcium carbonate to the site.

The present invention to achieve the above object is

(1) chipping the cross section of the concrete structure that needs repair reinforcement to trim until the undamaged portion comes out;

(2) applying a calcium hydroxide aqueous solution having a pH of 9 to 12 as an aqueous solution obtained by dissolving calcium hydroxide in water on the finished concrete section;

(3) As a process of dissolving carbon dioxide in the mixed solution of water and alcohol on the surface coated with the aqueous solution of calcium hydroxide to treat nanobubble water treated with nano size, the calcium carbonate water is based on 100 parts by weight of total calcium carbonate. (CaO) using a dissolved 0.01 to 1.0 parts by weight;

(4) A binder is prepared by mixing 20-50% by weight fast cement, 30-60% by weight Portland cement, 5-30% by weight of alpha type gypsum and 0.1-5.0% by weight of nitrite powder on the surface treated with the carbonic acid nanobubble water. After preparing and mixing the filler and the aggregate to the binder, the step of mixing the mortar composition prepared by mixing with water to apply;

(5) applying a surface protective agent to the surface coated with the mortar composition

It provides a method of repairing and reinforcing the cross-section of a concrete structure including.

In one embodiment of the present invention, in applying the aqueous calcium hydroxide solution in (2), it is divided into a first step of treating a calcium hydroxide solution of pH 11-12 and a second step of treating a calcium hydroxide solution of pH 9-10. It is characterized by applying.

In addition, in an embodiment of the present invention, in the step of treating the carbon nanobubble water in (3), water and alcohol are each mixed at a ratio of 100: 0.1 to 100.

In addition, in one embodiment of the present invention, in the process of treating the carbonic acid nanobubble water in (3), the carbonic acid nanobubble water is characterized in that the pH is adjusted to 4 to 6.5.

In addition, in one embodiment of the present invention, in the process of treating the carbonic acid nanobubble water in (3), the carbonic acid nanobubble water is characterized in that it is treated for 1 to 6 hours.

In addition, in one embodiment of the present invention, as the carbonic acid nanobubble water is treated in (3), CaCO ₃ crystals in the form of calcite in the micro-cracks of concrete and CaCO in the form of vaterite _It is characterized by self-healing the concrete by filling the micro-crack pores by forming a mixed crystal of ₃ crystals.

In addition, in one embodiment of the present invention, in the above (4), the fastening cement is composed of 20 to 50 parts by weight of the slag-containing mixture and 20 to 40 parts by weight of phosphate gypsum phosphate, and the slag-containing mixture is Mechanochemically activated mixture for mixing and grinding a mixture consisting of 40 to 80% by weight of blast furnace slag, 10 to 30% by weight of lime, and 5 to 45% by weight of flue gas desulfurization gypsum having a surface area of 4,000 to 7,000 cm ² / g It is characterized by being.

In addition, in one embodiment of the present invention, the nitrite powder in (4) is characterized by using a specific surface area of 1,000 to 8,000 cm ² / g.

In addition, in one embodiment of the present invention, the nitrite powder in (4) is characterized in that it is lithium nitrite, potassium nitrite or calcium nitrite.

In addition, in one embodiment of the present invention, it is characterized in that the reinforcing bar rust preventive agent is not applied to the reinforcing bar exposed after step (1) chipping.

In addition, in one embodiment of the present invention, the mortar composition for repair is characterized in that it further comprises 0.1 to 3% by weight of a water-in-water separator.

At this time, the water-in-water separator is characterized in that at least one selected from methyl cellulose, hydroxymethyl cellulose, carboxymethyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxyethyl cellulose, hydroxypropyl cellulose.

In addition, in one embodiment of the present invention, the mortar composition for repair of (4) is 0.1 to 10 parts by weight of a dispersant, 0.01 to 3 parts by weight of an antifoaming agent, and 0.01 to 10 parts by weight of a retarder relative to 100 parts by weight of the binder. Characterized in that it further comprises at least one additive selected.

In addition, in one embodiment of the present invention, the filler of (4) is characterized in that at least one selected from limestone, lime powder, talc.

In addition, in one embodiment of the present invention, the aggregate of (4) is characterized in that the particle size is 0.2 ~ 2.5mm silica sand.

The features and advantages of the repair and reinforcement method of the concrete structure section according to the present invention are as follows.

First, since an organic polymer material is not used as a crack repair material, problems of the organic material, that is, deformation / deterioration due to heat, vulnerability to fire, generation of harmful gas, and deterioration of physical properties over time can be prevented.

In addition, as in the conventional self-healing mechanism of concrete microcracks, calcium carbonate is not generated only at the crack inlet, but the calcium carbonate crystals are filled up to the deep part of the microcracks, thus preventing the further progress of cracks, thereby improving the physical properties of concrete raw materials. Can recover.

In other words, the calcium carbonate crystals are not only present in the form of a large calcite crystal size, but can also fill up the space that the calcite cannot fill by forming together with a fine crystal size (1/10 to 1/100 compared to calcite) vaterite. And by combining with calcitic, the crack filling effect is large and it can contribute to the improvement of water tightness and strength of the concrete, and by forming a dense structure at the crack site, it is possible to perform fundamental self-healing.

Accordingly, it is possible to prolong the life of the concrete structure and to increase the waterproofing effect by densifying the pores of the concrete, while at the same time, in the case of coastal or offshore structures, it is possible to protect the concrete by strengthening the salt-prevention properties and improving the acid resistance. It has the advantage of maximizing the repair and reinforcement effect of the concrete structure.

1 to 11 show the experimental results according to the embodiment of the present invention.

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

As described above, the present invention comprises the following steps. In other words,

(1) chipping the cross section of the concrete structure that needs repair reinforcement to trim until the undamaged portion comes out;

(2) applying a calcium hydroxide aqueous solution having a pH of 9 to 12 as an aqueous solution obtained by dissolving calcium hydroxide in water on the finished concrete section;

(3) As a process of dissolving carbon dioxide nanobubble water treated with bubbles in nano size by dissolving carbon dioxide in a mixed solution of water and alcohol on the surface coated with the aqueous calcium hydroxide solution, based on the total weight of 100 parts by weight of the carbon dioxide nanobubble water Using calcium oxide (CaO) dissolved in 0.01 to 1.0 parts by weight;

(4) A binder is prepared by mixing 20-50% by weight fast cement, 30-60% by weight Portland cement, 5-30% by weight of alpha type gypsum and 0.1-5.0% by weight of nitrite powder on the surface treated with the carbonic acid nanobubble water. After preparing and mixing the filler and the aggregate to the binder, the step of mixing the mortar composition prepared by mixing with water to apply;

(5) applying a surface protective agent to the surface coated with the mortar composition

Hereinafter, each step will be described in detail.

1. Chipping section of concrete structure

As the concrete structure cracks due to deterioration, etc., over time, the compressive strength of the concrete and the tensile strength of the reinforcing bar gradually decrease, and the concrete exposed to the crack site undergoes neutralization and corrosion of the reinforcing bar occurs. If such a phenomenon occurs by conducting safety diagnosis and inspection, the section of the concrete structure must be repaired and reinforced to maintain the life of the building for a long time.

The chipping step is a process of crushing and refining the cross section using a machine until concrete that needs repair reinforcement as a result of safety diagnosis and inspection removes cracked concrete and exposed reinforcing bars until undegraded concrete appears. At this time, it is preferable that the outermost surface of the polished concrete has a rough surface so that the mortar can be easily attached.

2. Applying calcium hydroxide aqueous solution

The concrete section is chipped to remove the deteriorated concrete and corrosion reinforcing bar, and then an aqueous calcium hydroxide solution is applied.

The calcium hydroxide solution is an aqueous solution obtained by dissolving calcium hydroxide in water, and it is preferable to use those having a pH in the range of 9 to 12.

More specifically, it is preferable to apply the calcium hydroxide solution having a pH of 11 to 12 in the first step, and then to treat the calcium hydroxide solution having a pH of 9 to 10 in the second step.

The separation of the above steps is mainly because calcitic crystals are mainly formed when reacting with carbonate ions in the pH range of the first step, and vaterite crystals are mainly formed when reacting with carbonate ions in the pH range of the second step. A detailed description of this will be provided later.

The application of the aqueous calcium hydroxide solution in this step is preferably carried out until the chipping site of the concrete is sufficiently deposited, and more specifically, it is preferable to treat the aqueous solution to be delivered to the deep inside the pores of the micro-cracks.

In addition, in this step, the application of the aqueous calcium hydroxide solution is preferably applied at a temperature of 20 to 40 ° C, at which temperature the formation of calcium carbonate crystals in the subsequent step can be activated.

3. Treatment of carbonic acid nanobubble water

The surface of the aqueous solution of calcium hydroxide is treated with ionized carbonated water. In this case, the carbonated ionized water used is preferably carbonic acid nanobubble water in which carbon dioxide is dissolved in a mixture of water and alcohol and treated with nano-sized bubbles.

The number of nano-carbonate bubbles is made of nano-sized bubbles. Since it can penetrate deep inside the micro-cracks of concrete structures, it reacts with calcium ions (including calcium ions separated from concrete structures) to form calcium carbonate crystals. do.

At this time, the method for manufacturing the carbonic acid nanobubble water may use an existing bubble water production device, and may be manufactured using a bubble water production device that mixes water and alcohol and carbon dioxide and rotates at a high speed. The water and alcohol (eg, ethanol) are preferably mixed in a weight ratio of 100: 1 to 100, respectively. In addition, in this case, it is preferable to add a small amount of calcium oxide (CaO), specifically, based on 100 parts by weight of the total weight of the obtained carbonic acid nanobubble, calcium oxide is added in an amount of 0.01 to 1.0 parts by weight to produce carbonic acid nanobubble water. Can be. Since the calcium oxide added in this way is included in a trace amount, reaction with carbonate ions is rarely generated, and since calcium ions are formed and mixed with bubble water, it can be delivered to the deep portion of the microcracks to contribute to the formation of calcium carbonate crystals. . In addition, by increasing the reaction rate between calcium ions and carbonate ions, it is possible to increase the production of calcium carbonate crystals after self-healing regardless of temperature conditions.

In addition, it is preferable to inhibit the reaction with the calcium carbonate, which is mixed in a trace amount, the pH of the nano-bubble water is preferably adjusted in the range of 4 to 6.5.

In addition, the carbonic acid nanobubble water is preferably treated for a time period within which a sufficient reaction can be achieved, and is preferably treated to the extent that microcracks are deposited. Specifically, it is preferably treated for 1 to 6 hours.

As the carbonic acid nanobubble water is treated, mixed crystals of Calcite-like CaCO ₃ crystals and vaterite-like CaCO ₃ crystals are formed on the micro-cracks of concrete, thereby rehydrating and re-hydrating cement particles. Due to the precipitation of CaCO3, a self-healing phenomenon in which a crack site is filled may occur.

Specifically, the crystals of calcium carbonate can be typically classified into three types: calcite, vaterite, and aragonite. Among the structures, calcium hydroxide and calcium ions in the supplied external aqueous calcium hydroxide solution are external. Calcium carbonate is formed by combining with carbonic acid ions of nanobubble carbonate supplied from, and most of the crystals produced at this time have a calcitic shape.

On the other hand, by adjusting the pH of the aqueous calcium hydroxide solution to form other crystals, when the pH range is set to 9 to 10, a vaterite crystal is formed. Vaterite is a hexagonal crystal, which has a slightly smaller density than calcite, but has a crystal size of about 1/10 to 1/100, and has a stable crystal shape, so the pore filling effect is superior to that of calcite. Therefore, it is possible to fill up the part where the calcite is not filled and also fill the space between the calcites to form dense crystals with the calcite, thereby contributing to the improvement of water tightness and strength of the concrete.

4. Applying mortar composition for repair

It is repaired by applying a repair mortar composition to the surface treated with the carbonic acid nanobubble water.

The mortar composition for repair used in the present invention uses the following composition in order to secure fast-resistance and strength.

That is, after preparing a binder by mixing 20-50% by weight cement, 30-60% by weight Portland cement, 5-30% by weight of alpha-type gypsum plaster and 0.1-5.0% by weight of nitrite powder, the filler and aggregate are added to the binder. The mortar composition for repair prepared by mixing is mixed with water and applied.

Specifically, the fastening cement is composed of 20 to 50 parts by weight of the slag-containing mixture and 20 to 40 parts by weight of phosphate gypsum, and the slag-containing mixture has a specific surface area of 4,000 to 7,000 cm ² / g and blast furnace slag 40 to 40 It is characterized in that the mixture consisting of 80% by weight, 10 to 30% by weight of lime, and 5 to 45% by weight of heat-desulfurized gypsum is a mechanochemically activated mixture that is mixed and ground in a vibration mill.

The present invention is used by mixing the alpha-type gypsum gypsum to the obtained rapid-hardening cement.

That is, when only the fast-cement cement is used, the initial shrinkage occurs due to the fast curing time. Therefore, only the fast-cement cement is used due to the complementary effect between them by mixing and using an alpha-type semi-gypsum gypsum having a hydration rate similar to the fast-cement cement. Curing shrinkage may be reduced compared to the case. Therefore, it is possible to prevent the initial cracking and obtain a result that the initial strength is further improved compared to the case of using the fastening cement alone.

In addition, in the present invention, nitrite powder is mixed and used to protect reinforcing bars.

Specifically, lithium nitrite, potassium nitrite, calcium nitrite, and the like can be used as the nitrite powder, and preferably, a specific surface area of 1,000 to 8,000 cm ² / g is used.

The nitrite powder promotes the hydration reaction with C3A contained in the cement and increases the amount of ethrinite, thereby contributing to strengthening the initial strength of mortar. In addition, since the nitrite powder serves to protect the reinforcing bar inside, the process of separately applying the reinforcing bar rust inhibitor after chipping can be omitted.

The nitrite powder is preferably contained in 0.1 to 5.0% by weight in the binder. If the amount is less than 0.1% by weight, the effect of promoting hydration and protecting the reinforcing bar decreases, and when it exceeds 5.0% by weight, the fluidity of the mortar decreases and workability may deteriorate.

The present invention is to prepare a binder by mixing 20-50% by weight fast cement, 30-60% by weight Portland cement, 5-30% by weight of alpha-type gypsum plaster and 0.1-5.0% by weight of nitrite powder, and then filler and aggregate in the binder It is used by mixing a water-forming mortar composition prepared by mixing with water.

In addition, in order to reinforce and repair the underwater concrete structure, an underwater fire separating agent may be additionally included in a range of 0.1 to 3% by weight. The water-in-water separator is added to prevent decomposition by improving the viscosity of the mortar composition in water, and methyl cellulose such as methyl cellulose, hydroxymethyl cellulose, and carboxymethyl cellulose; Ethyl cellulose such as ethyl cellulose, hydroxyethyl cellulose, and carboxyethyl cellulose; Cellulose thickeners selected from propyl cellulose such as hydroxypropyl cellulose can be used. It is preferable to use the content of 0.1 to 3% by weight since it exhibits appropriate viscosity. If necessary, a water-soluble acrylic resin powder may be further added to further increase the viscosity in water. The water-soluble acrylic resin powder is preferably used in 1 to 30 parts by weight based on 100 parts by weight of the water-in-water separator.

In addition, if necessary, with respect to 100 parts by weight of the binder, 0.1 to 10 parts by weight of a dispersant, 0.01 to 3 parts by weight of an antifoaming agent, and 0.01 to 10 parts by weight of a retardant may further include one or more additives.

In the present invention, the fast-cemented cement prepared by the above method is a mixture of calcium sulfo aluminate and calcium, as a mixture of CaO source cement, CaSO ₄ source phosphoric acid gypsum and reinforcing bar protective nitrite powder is used at the above mixing ratio. To form an aluminate. When mixed with water, the calcium sulfoaluminate mainly produces ettringite or calcium hydroxide by hydration, thereby promoting hydration. In addition, ethrinite of needle-like crystals produced by hydration reaction fills micropores of cement mortar and concrete to express or expand strength, so that mortar with excellent strength and high curing rate can be produced. The calcium aluminate is a general term for a substance having a hydration activity mainly composed of CaO and Al ₂ O ₃ . Specifically, the calcium aluminate reacts with water to form various calcium aluminate hydrates, and is rapidly made in the early stage of the reaction, so that a mortar composition exhibiting fast-hardness can be prepared.

In the present invention, the fastening cement is preferably used 20 to 50% by weight of the total binder component. If it is less than 20% by weight, the mortar strength decreases and a fast curing time cannot be obtained, and if it exceeds 50% by weight, rapid curing properties may be obtained, but cracks may occur due to overexpansion due to interaction with alpha-type hemihydrate gypsum. .

In the present invention, the portland cement among the binder components is used to express late strength of mortar, and it is preferable to use one type of portland cement, and it is preferable to use 30 to 60% by weight of the total binder component.

In the present invention, the alpha-type gypsum among the components of the binder reacts with fast-hardening cement at the beginning of hydration to generate a large amount of ethrinite that expresses the initial strength and expansion of mortar, thereby preventing excellent compression strength and cracking due to shrinkage Used to play a role, it is preferable to use 5 to 30% by weight of the total binder component. If it is less than 5% by weight, it is difficult to express the quick-drying property or expandability of the mortar, and if it is more than 30% by weight, it may cause cracking due to overexpansion and an increase in the raw material price.

In the present invention, the fastening cement, portland cement, alpha-type gypsum plaster, and the binder made of nitrite powder is preferably included in 20 to 50% by weight of the mortar composition for the repair of the concrete structure. When used at less than 20% by weight, the initial strength decreases and adhesion decreases, and when it exceeds 50% by weight, initial cracking may occur due to rapid curing and high heat of hydration when used.

The mortar composition for repairing the concrete structure of the present invention may include a filler and aggregate in addition to the binder, and may additionally include a water-in-water separator.

Specifically, the filler may use one or more selected from limestone, lime powder, and talc, and its content is preferably used in a range of 5 to 20% by weight. If it is less than 5% by weight, the effect of suppressing the shrinkage of the cured body is insignificant and there is a fear that the amount of dry shrinkage increases. When it exceeds 20% by weight, the amount of filler may be excessive and fluidity and workability may decrease.

The aggregate is preferable because silica sand is suitable, and the particle size of the silica sand is 0.2 mm to 2.5 mm, since it is not separated from each other and is suitable for producing a mortar with good adhesion. The aggregate preferably has a ratio of 40 to 70% by weight with respect to the total mortar in consideration of the workability for the mortar.

In addition, the present invention may further include one or more additives selected from 0.1 to 10 parts by weight of a dispersant, 0.01 to 3 parts by weight of an antifoaming agent, and 0.01 to 10 parts by weight of a retarder, based on 100 parts by weight of the binder, if necessary.

The dispersant adsorbs on the surface of the particle of mortar and charges the surface of the particle to cause mutual reaction between the particles, thereby dispersing the agglomerated particles to increase the flow, thereby enhancing strength due to the water-reducing effect. As the dispersing agent, a conventional water reducing agent can be used, and for example, it can be used alone or in combination of two or more from the group consisting of lignin sulfonate, polynaphthalene sulfonate, polymelamine sulfonate or polycarboxylate-based water reducing agents. The content of the dispersant is preferably used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the binder, and when used in an amount of less than 0.1 parts by weight, the performance is not achieved, and when it exceeds 10 parts by weight, mortar due to excessive use It has the disadvantage that material separation occurs due to its low viscosity.

The antifoaming agent is used to remove the large pores in the mortar to improve the strength and appearance of the mortar. Antifoaming agents include mineral oil-based antifoaming agents such as kerosene and liquid paraffin; Oil and fat defoamers such as animal and vegetable oils, sesame oil, castor oil and alkylene oxide adducts thereof; Fatty acid antifoaming agents such as oleic acid, stearic acid and alkylene oxide adducts thereof; Fatty acid ester-based antifoaming agents such as glycerin monoricinolate, alkenyl succinate fluid, sorbitol monolaurate, sorbitol trioleate, natural wax, and the like; Polyoxyalkylenes, (poly) oxyalkyl ethers, acetylene ethers, (poly) oxyalkylene fatty acid esters, (poly) oxyalkylene sorbitan fatty acid esters, (poly) oxyalkylenealkyl (aryl) ethers Oxyalkylene-based antifoaming agents such as sulfate ester salts, (poly) oxyalkylene alkyl phosphate esters, (poly) oxyalkylenealkylamines, (poly) oxyalkyleneamides, etc .; Alcohol-based antifoaming agents such as octyl alcohol, hexadecyl alcohol, acetylene alcohol and glycols; Amide antifoaming agents such as acrylate polyamines; Phosphate ester antifoaming agents such as tributyl phosphate and sodium octyl phosphate; Metal soap-based antifoaming agents such as aluminum stearate and calcium oleate; Silicone-based antifoaming agents such as dimethyl silicone oil, silicone paste, silicone emulsion, organic modified polysiloxane (polyorganosiloxane such as dimethyl polysiloxane), fluorosilicone oil, and the like can be used. The antifoaming agent is preferably used in an amount of 0.01 to 3 parts by weight based on 100 parts by weight of the binder, and when used in an amount of less than 0.01 parts by weight, the performance of removing bubbles generated when stirring is significantly lowered, and when it exceeds 3 parts by weight, the composition There is a disadvantage of lowering the strength of.

The retarder may be added for the purpose of securing workability for a period of time by adjusting the hydration rate of the binder. Retarders include boric acid and borates such as borax, sodium borate and potassium borate, gluconic acid, citric acid, tartaric acid, glucoheptonic acid, arabic acid, malic acid or citric acid and their sodium, potassium, calcium, magnesium, ammonium, and triethanolamine Oxycarboxylic acids such as inorganic salts or organic salts; Monosaccharides such as glucose, fructose, galactose, saccharose, xylose, abitose, lipoose, isomerized sugar, oligosaccharides such as disaccharides, trisaccharides, or oligosaccharides such as dextrins, or polysaccharides such as dextran, Sugars such as molasses containing them; Sugar alcohols such as sorbitol; Magnesium fluoride; Phosphoric acid and salts or boric acid esters thereof; Aminocarboxylic acids and salts thereof; Alkali-soluble protein; Fumic acid; Tannic acid; phenol; Polyhydric alcohols such as glycerin; Aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) and alkali metal salts thereof, alkali Phosphonic acids such as earth metal salts and derivatives thereof can be used. The content is preferably added to 0.01 to 10 parts by weight based on 100 parts by weight of the binder.

In this step, when the mortar composition is repeatedly applied one or more times during application, it is desirable to finish roughly by polishing the outermost surface of the chipped section for adhesion to the target surface. The applying step is preferably 5 to 15 mm for the first pouring using spray or trowel, 20 to 50 mm for the second and third pouring, and 5 to 15 mm for final pouring, but the thickness is chipped concrete It can be changed depending on the thickness.

5. Applying surface protection agent

The mortar composition may be applied to a concrete crushing site to finish smoothly, and after drying, a surface protective agent according to the present invention may be applied to the surface to protect it.

The surface protection agent may use an epoxy-based paint or an unsaturated polyester-based paint, and the like, but the present inventor can use the paint proposed in a separate patent (Republic of Korea Patent No. 10-1284603), but is not limited thereto. Surface protective agents generally used in the art to which the invention pertains may be used without limitation.

Hereinafter, the present invention will be described in more detail based on Examples. However, the scope of the present invention is not limited by the following examples.

[Example]

In the self-healing of cement-based composite materials, since the main reaction material is influenced by the hydration products by hydration reaction between cement particles and water, in this embodiment, it is possible to change the crystalline form of CaCO3 produced in the cement paste cured body by adjusting the pH. Evaluation was carried out.

1. Experimental method

Cement was usually made of Portland cement (C, density: 3.16 g / cm ³ , average particle diameter of 10 μm) to prepare a cement paste test specimen (φ10Х30mm) having a water-cement ratio of 40%. In order to prevent the evaporation (dissipation) of moisture, the test body was subjected to suture curing in a constant temperature and humidity room at a temperature of 20 ± 1 ° C and a humidity of 60% from immediately after pouring to 1 day of age. Subsequently, the molded specimen was cured in water in a water bath at a water temperature of 20 ° C ± 1 ° C until 28 days of age. After 28 days of age, the specimens cut to a size of φ10Х3mm were examined for changes in the crystalline form of CaCO3 according to the pH change and the amount of production thereof.

In order to grasp the effect on the change of the crystalline form and porosity of CaCO3 according to changes in pH conditions, an aqueous Ca (OH) 2 solution and an aqueous NH3 solution (comparative example) were used. At this time, as a solvent for adjusting the pH, the pH was adjusted by a pH control device using Terephthalic Acid in the case of Ca (OH) 2 aqueous solution and Ammonium Chloride in the case of NH3 aqueous solution. In addition, under the temperature condition of 20 ° C., the experiment was conducted by setting the pH conditions at which each crystalline form of CaCO 3 was formed to three levels of pH9.0, pH10.5, and pH12.0, and the self-healing period was set to 7 days.

As an experimental method, first, the test piece cut to a size of φ10Х3mm was dried in a drying furnace at 105 ° C. for 1 day to measure the absolute dry weight before self-healing. Thereafter, the test body was immersed in water for 1 day to make it wet, and the water weight and surface dry weight before self-healing (Step A) were measured. Thereafter, the test body was immersed in a Ca (OH) 2 aqueous solution and an NH 3 aqueous solution with pH adjustments for 7 days. After 7 days immersion, the specimen was immersed in acetone for 4 hours or more to stop the hydration reaction, and in the same manner as before self-healing, the absolute dry weight, surface dry weight, and underwater weight after self-healing (Step B) Measured. Subsequently, absolute dry density, water absorption, and porosity were calculated using the weights of the specimens before and after self-healing (Step. A) and afterwards, and physical property changes due to self-healing were comparatively evaluated.

2. Experimental results

(1) Changes in physical properties

Since the cement paste cured body is a porous structure having a large amount of voids, in order to evaluate the change in the amount of voids of the test body before and after self-healing, the void reduction rate due to the change in weight and absorption rate before and after self-healing was measured. In other words, the porosity reduction was calculated through the correlation between the weight change of the specimen before and after self-healing and the theoretical model of the amount of production and the porosity of the proposed hydration product. Then, the self-healing filling effect by changing the crystal form with CaCO3 was evaluated in comparison with the void reduction rate due to the change in the actual absorption rate. In addition, to evaluate the change in the pore structure, the pore structure was measured using a mercury intrusion porosimeter (MIP). In addition, among the crystals of CaCO ₃ , which is a major precipitate of self-healing, in order to grasp the control of polymorphisms scale formation to vaterite, which has a denser crystal structure than calcite, SEM analysis of each specimen according to changes in pH conditions was performed. . However, based on the results of physical performance evaluations such as absolute dry density and absorption rate, the pore volume change and MIP and SEM analysis were conducted using only the CH series using Ca (OH) 2 aqueous solution.

1 to 4 show the results of the absolute dry density and absorption rate of each test sample according to the pH change under the immersion conditions of the Ca (OH) 2 aqueous solution and the NH3 aqueous solution. First, as shown in FIGS. 1 and 2, in the case of the CH series, regardless of the pH change, the absolute dry density after self-healing (Step B) slightly increases compared to before self-healing (Step A), and the absorption rate is about It tended to decrease by about 1%. In particular, the dry density of each pH change tended to increase by 1.4% for pH9.0, 1.5% for pH10.5, and 2.4% for pH12.0.

Meanwhile, as shown in FIGS. 3 and 4, in the case of the NH series, the absolute dry density after self-healing (Step. B) is slightly reduced compared to before self-healing (Step. A), and the absorption rate tends to increase somewhat. Showed. The dry density of each pH change decreased by 3.6% for pH9.0, 1.2% for pH10.5, and 4.5% for pH12.0, showing the opposite trend from that of the CH series.

5 and 6 show the porosity calculation results of the CH series and the NH series. First, in the case of the CH series, a decrease in porosity of 7.1% for pH9.0, 7.4% for pH10.5, and 6.9% for pH12.0 was confirmed. On the other hand, in the case of the NH series, pH9.0 was 11.0%, pH10.5 was 9.6%, and pH12.0 was confirmed to increase the porosity of 7.8%, showing a similar tendency to the absorption rate result.

From the above results, in the immersion conditions of the Ca (OH) 2 aqueous solution and the NH 3 aqueous solution, the cause of the difference in the absolute dry density, absorption rate, and porosity change is caused by the change in the absolute amount of Ca ²⁺ ions supplied after CaCO3 self-healing. It is judged to affect the production amount. That is, in the case of the CH series using the Ca (OH) 2 aqueous solution, compared with the NH 3 aqueous solution (NH series), a large amount of Ca ²⁺ ions penetrated inside the test body, and it was determined that the amount of CaCO 3 self-healing precipitate increased. do. On the other hand, in the case of the NH series, as compared to the CH series, it is presumed that calcium (Ca) in the cement paste cured body was eluted in an aqueous solution as a factor in which the absolute dry density decreased and the water absorption and porosity increased.

(2) Pore reduction change

를 구했다.Using the actual absorption rate before and after self-healing of the CH series due to the change in pH, to examine the filling effect with CaCO3, substitute the experimental values in the following formula and reduce the voidage by carbonization after self-healing.

I got it.

：자기치유 전(A)의 공극율,

：자기치유 후(B)의 공극율 이다.here,

: Porosity before self-healing (A),

: Porosity after self-healing (B).

On the other hand, for the microscopic examination of the CaCO3 filling effect using the actual weight change under the same conditions as the void reduction rate by the above absorption rate, using the theoretical model of the amount of production and the porosity of the hydration product proposed by Papadakis, carbonization after self-healing The void reduction rate by was determined.

[g] 및 반응율

[%]를 이하의 하기 식을 통해 구할 수 있다.Here, when Ca (OH) 2 (= 74 [g / mol]) changes to CaCO3 (= 100 [g / mol]), the weight of 26 g per 1 mol increases. Based on the theoretical model of the production amount and porosity of the hydrated products of Papadakis, the total weight increase when Ca (OH) 2 is changed to CaCO3 after self-healing of the CH series under each pH condition

[g] and reaction rate

[%] Can be obtained through the following equation.

：자기치유 전(A)의 중량[g],

：자기치유 후(B)의 증감된 중량[g] 이다.here,

: Weight (g) before self-healing (A),

: It is the weight [g] increased or decreased after self-healing (B).

At this time, based on the following formula proposed by Papadakis [Vagelis G. Papadakis; Costas G. Vayenas; and Michael N. Fardis. Physical and Chemical Characteristics Affectiong the Durability of Concrete, ACI Materials Journal , 1991, 88-M24, 186-196], Ca (OH) 2 concentration was calculated.

：시간 t에 대한 물질 i의 반응율,

,

：물질 i의 시간 t에 대한 농도 및 초기농도[mol/m³],

：20°C일때, 물질 i의 반응속도정수[1/sec],

：실험에 의한 수치 이다.here,

: Reaction rate of substance i with respect to time t ,

,

： Concentration and initial concentration of substance i over time t [mol / m ³ ],

: At 20 ° C, the reaction rate constant of substance i [1 / sec],

: It is a value by experiment.

를 구하기 위해, Papadakis의 탄산화에 의한 공극율을 응용한 하기 식을 이용했다. Finally, using actual weight change, the void reduction rate by carbonation after self-healing

In order to obtain the following formula, the porosity by carbonation of Papadakis was applied.

：후레쉬 콘크리트의 초기 공극율,

：수화반응에 의한 공극율,

：탄산화에 의한 공극감소율이다.here,

： Initial porosity of fresh concrete,

: Porosity by hydration reaction,

: Pore reduction rate by carbonation.

)는 흡수율 결과를 이용하였으며, 계산치(

)는 중량변화와 Papadakis의 모델을 이용하였다. Fig. 7 shows the results of the void reduction rate due to carbonation of the CH series according to the pH change. Here, the experimental value (

) Used the absorption rate result, and the calculated value (

) Used the model of weight change and Papadakis.

) 가 계산치(

)와 비교해, pH9.0는 1.0%, pH10.5는 1.2%, pH12.0는 0.7% 정도 공극감소율이 증가하였지만, 그 차이는 크지 않았다. 따라서, W/C 40%의 경우, 자기치유 전후의 흡수율 변화를 통해 구해진 공극량 변화와 거의 동일한 결과로부터, 중량변화와 Papadakis의 모델을 이용하여, 자기치유 후의 탄산화에 의한 공극량 변화의 예측이 가능하다고 판단된다. 다만, Papadakis가 제안하는 수화 생성물의 생성량 및 공극률의 이론적 모델을 본 연구에 적용할 경우, 본 연구에서의 자기치유를 실시한 시험체에서는 Ca(OH)2만이 탄산화에 의한 공극변화에 기여 하는 것으로 가정하여, 평가를 실시했다. 따라서, 본 실험에서의 실제 흡수율에 의한 공극량 변화와 비교해, 약 1%정도 차이가 발생되는 것을 확인할 수 있다. 그러므로, 추후, 자기치유 후의 C-S-H gel, Ettringite, Friedel's salt 등 Ca(OH)2 이외의 수화생성물의 탄산화로 인한 공극량 변화의 정량적 검토가 필요하다.As a result of the experiment, regardless of the pH change, the experimental value after self-healing (Step B) (

) Is calculated

), The void reduction rate increased by 1.0% for pH9.0, 1.2% for pH10.5, and 0.7% for pH12.0, but the difference was not significant. Therefore, in the case of W / C 40%, it is possible to predict the change in the amount of voids due to carbonization after self-healing, using the model of weight change and Papadakis from the results almost identical to the changes in the amount of voids obtained through the change in the absorption rate before and after self-healing. Is judged. However, when applying the theoretical model of the amount and porosity of hydration products proposed by Papadakis to this study, it is assumed that Ca (OH) 2 only contributes to the pore change due to carbonation in the specimen subjected to self-healing in this study. , Was evaluated. Therefore, it can be seen that a difference of about 1% is generated compared to the change in the amount of voids due to the actual absorption rate in this experiment. Therefore, it is necessary to quantitatively examine changes in pore volume due to carbonation of hydration products other than Ca (OH) 2, such as CSH gel, Ettringite, and Friedel's salt after self-healing.

(3) Structural changes in voids

8 and 9 show the results of measuring the pore distribution before and after self-healing of the CH series using a mercury intrusion porosimeter (MIP). Here, the vertical axis of the graph represents the amount of voids and cumulative voids (%), and the horizontal axis represents the diameter in the pores.

As a result of measuring the amount of voids in FIG. 8, in the range of the pore diameter of 0.1-1 μm, after the self-healing (Step B) compared to before the self-healing (Step A) regardless of the pH change, the pore distribution is shifted toward the smaller side. Confirmed. In addition, in the vicinity of the pore diameter of 0.1 to 0.01 μm (capillary pore), a tendency of a slight increase in the amount of pores after self-healing (Step B) was observed. In addition, as a result of measuring the cumulative pore amount of FIG. 9, after self-healing (Step B) compared to before self-healing (Step A), pH 9.0 is about 4%, pH 10.5 is about 2.2%, pH 12.0 is The pore amount decreased by about 2.1%, but the difference according to the pH change was not large.

From these results, in the case of self-healing using an aqueous solution of Ca (OH) 2, since the absolute amount of Ca ²⁺ ions present in the aqueous solution of Ca (OH) 2 increases compared to before self-healing, the amount of CaCO3 generated in the cured cement paste increases Contributed to, it is determined that the voids are filled.

(4) Crystal structure change according to pH change

In order to confirm the possibility of generation and control of bariterite which is a more dense CaCO3 compound by pH adjustment, SEM analysis was performed under each pH condition using the CH series. When self-healing was performed using a Ca (OH) 2 aqueous solution, SEM images of the test body for two conditions of 9.0 and 12.0 for each pH condition are shown in FIGS. 10 and 11, respectively. The SEM observation was performed on the split surface of the φ10Х3mm specimen (inside the specimen), and the CaCO3 crystal form and crystal size confirmed in the existing literature were compared with the crystal structure obtained in this study [24, 25]. The crystalline form was judged and estimated.

As a result of SEM analysis, in the case of pH9.0 and pH12.0, Ca (OH) 2 was hardly observed in cement hydrate, and vaterite was mainly observed at pH9.0, and calsite at pH12.0. Based on these results, when self-healing by pH adjustment is performed, it is determined that the crystalline form of CaCO3 generated in the cement matrix can be controlled by vaterite and calcitic. In particular, by adjusting the pH to about 9.0 under the condition of a temperature of 20 ° C., it is judged that it is possible to effectively produce and control bariterite, which is a more dense CaCO 3 crystal.

3. Experimental conclusion

From the above experiment, when self-healing using an aqueous solution of Ca (OH) 2, the absolute amount of Ca ²⁺ ions supplied is greater than that of the NH 3 aqueous solution, and thus, inside the cement paste cured body after self-healing regardless of the pH condition. It was confirmed that the production of CaCO3 was increased, and due to these causes, the absolute dry density increased, and the absorption rate and porosity decreased, and thus it is considered that more effective self-healing is possible.

In addition, since the difference between the actual absorption rate and the void reduction rate through weight change is not large, the actual weight change before and after self-healing and the application of the theoretical model of the production and porosity of hydration products proposed by Papadakis, the amount of voids by self-healing It is judged that it is possible to evaluate the change and predict the self-healing filling effect.

In the case of self-healing using an aqueous solution of Ca (OH) 2, by adjusting the pH, pH9.0 is mainly vaterite, pH10.5 is aragonite, pH12.0 is mainly calcite, and CaCO3 generated in cement matrix Crystalline change was confirmed. In particular, by adjusting the pH to about 9.0 under the condition of a temperature of 20 ° C., the possibility of effectively generating and controlling bariterite, which is a more dense CaCO 3 crystal, was confirmed.

From the above experimental results, by setting the construction conditions along with the pH change of the calcium hydroxide aqueous solution, it is possible to form crystalline mixtures of calcitic and vaterite in the pores, so that reaction ions can be deposited to deep inside the pores using nano-bubble carbonated water. By doing so, it is possible to regenerate the internal voids with concrete components, thereby extending the life of the concrete and maximizing the repair effect.

Claims (15)

(1) chipping the cross section of the concrete structure that needs repair reinforcement to trim until the undamaged portion comes out;
(2) applying a calcium hydroxide aqueous solution having a pH of 9 to 12 as an aqueous solution obtained by dissolving calcium hydroxide in water on the finished concrete section;
(3) As a process of dissolving carbon dioxide nanobubble water treated with bubbles in nano size by dissolving carbon dioxide in a mixed solution of water and alcohol on the surface coated with the aqueous calcium hydroxide solution, based on the total weight of 100 parts by weight of the carbon dioxide nanobubble water Using calcium oxide (CaO) dissolved in 0.01 to 1.0 parts by weight;
(4) A binder is prepared by mixing 20-50% by weight fast cement, 30-60% by weight Portland cement, 5-30% by weight of alpha type gypsum and 0.1-5.0% by weight of nitrite powder on the surface treated with the carbonic acid nanobubble water. After preparing and mixing the filler and the aggregate to the binder, the step of mixing the mortar composition prepared by mixing with water to apply;
(5) applying a surface protective agent to the surface coated with the mortar composition;
It includes,
In step (3), in the process of treating the carbonic acid nanobubble water, water and alcohol are each mixed at a weight ratio of 100: 0.1 to 100, thereby repairing and reinforcing a concrete structure section.
The method according to claim 1, in applying the aqueous solution of calcium hydroxide in the above (2), the first step of treating the calcium hydroxide solution of pH 11 to 12 and the second step of treating the calcium hydroxide solution of pH 9 to 10 is applied separately A method of repair and reinforcement of a section of a concrete structure characterized by.
delete The method according to claim 1, wherein in the process of treating the carbonic acid nanobubble water in the step (3), the carbonic acid nanobubble water has a pH adjusted to 4 to 6.5.
The method according to claim 1, wherein in the step of treating the carbonic acid nanobubble water in (3), the carbonic acid nanobubble water is treated for 1 to 6 hours.
The method according to claim 1, wherein the mixed crystals of CaCO ₃ crystals of calcite-like and vaterite-like CaCO ₃ crystals in the micro-cracks of concrete as the (3) is treated with the carbonic acid nanobubble water. A method of repair and reinforcement of a section of a concrete structure characterized by self-healing of concrete by forming and filling micro-crack pores.
The method according to claim 1, wherein the fastening cement in (4) is composed of 20 to 50 parts by weight of the slag-containing mixture and 20 to 40 parts by weight of gypsum phosphate, wherein the slag-containing mixture has a specific surface area of 4,000 to 7,000 cm. ² / g of blast furnace slag 40 to 80% by weight, lime 10 to 30% by weight, concrete characterized in that the mixture consisting of 5 to 45% by weight of flue gas desulfurization gypsum is a mechanochemical activated treatment mixture mixed and pulverized in a vibration mill Method of repair reinforcement of the structure section.
The method according to claim 1, wherein in (4), the nitrite powder has a specific surface area of 1,000 to 8,000 cm ² / g.
The method of claim 1, wherein the nitrite powder in (4) is lithium nitrite, potassium nitrite, or calcium nitrite.
The method according to claim 1, Reinforcement reinforcement method of a concrete structure cross-section, characterized in that the reinforcing bar rust inhibitor is not applied to the reinforcing bar exposed after step (1) chipping.
The method of claim 1, wherein the repair mortar composition further comprises 0.1 to 3% by weight of a water-in-water separator.
The concrete according to claim 11, wherein the water-in-water separating agent is at least one selected from methyl cellulose, hydroxymethyl cellulose, carboxymethyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxyethyl cellulose, and hydroxypropyl cellulose. Method of repair reinforcement of the structure section.
The method according to claim 1, wherein the mortar composition for repair of (4) is at least one additive selected from 0.1 to 10 parts by weight of a dispersant, 0.01 to 3 parts by weight of an antifoaming agent, and 0.01 to 10 parts by weight of a retarder relative to 100 parts by weight of the binder. Repair reinforcement method of the concrete structure section, characterized in that it further comprises.
The method according to claim 1, wherein the filler of (4) is a limestone, stone powder, repair and reinforcement method of a concrete structure section, characterized in that at least one selected from talc.
The method of claim 1, wherein the aggregate of (4) is a reinforcing method of repairing a concrete structure in cross-section, characterized in that it is silica sand having a particle size of 0.2 to 2.5 mm.

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