KR101165785B1 - Mortar composition for repairing concrete structure and using method thereof - Google Patents

Abstract

PURPOSE: An inorganic polymer mortar composition for repairing and reinforcing concrete structures and a repairing and reinforcing method of the structure using the same are provided to enhance rapid hardening, super strength, and corrosion resistance by using ultra rapid hardening cement as a main component. CONSTITUTION: An inorganic polymer mortar composition comprises 100.0 parts by weight of Portland cement, 80-100 parts by weight of silica sand, 2-15 parts by weight of cement, 15-40 parts by weight of slag, and 5-12 parts by weight of garnet. The inorganic polymer cement mortar composition comprises more than one or two kinds which are selected from 0.5-4.0 parts by weight of sepiolite, 0.05-0.85 parts by weight of a hardening accelerator, 0.5-3.5 parts by weight of fibrous reinforcing agent, 12-18 parts by weight of aluminate based expanding agent, 1.5-6.0 parts by weight of superplasticizer, and 4.5-7.5 parts by weight of redispersible powder resin. The Portland cement has particle size of 20-90 micro meters.

Description

Inorganic polymer cement mortar composition for repair and reinforcement of concrete structures and method for repair and reinforcement of structures using same {MORTAR COMPOSITION FOR REPAIRING CONCRETE STRUCTURE AND USING METHOD THEREOF}

The present invention relates to an inorganic polymer cement mortar composition for repairing a cross section of a concrete structure and a method for repairing the structure using the same, and more specifically, to cracking, peeling, and concrete caused by salt, alkali aggregate reaction, east sea, chemical corrosion, neutralization, etc. Reinforcement of defects in concrete structures such as fragility, reinforcement corrosion, lifting, and rebar exposure.

In general, concrete structures have been acknowledged that they can be used semi-permanently because they have high durability, but many recent studies and investigations of existing structures reveal that concrete structures cannot avoid ageing deterioration.

In particular, it is often seen that the original function is lost after decades.

As described above, there are various deterioration phenomena that shorten the life of concrete, but the corrosion of reinforcement by chlorides invading from the outside such as melting concrete or snow removing agent used in winter or manufacturing concrete using sea sand without salt removal The impact of concrete structures has been seriously investigated.

In addition, the reinforced concrete structure is cracked due to tensile stress in the tension-side concrete of the structure, and if the crack width is greater than a certain limit, the surrounding air and moisture invade the cracked portion and corrode the steel, and the infiltrated water freezes in winter. Inflate

It may damage concrete.

In addition, concrete is cracked due to drying shrinkage, temperature change, etc., and the neutralization of concrete at the cracked part and surface of the structure is promoted, and at the same time, the deterioration phenomenon occurs at the concrete part of the structure. There is a problem with the phenomenon.

Therefore, it is necessary to repair or reinforce the defect of the reinforced concrete structure, and the mortar used for the repair and reinforcement should be able to be substantially combined with the existing concrete structure when it is poured in addition to the existing surface or cross section.

However, conventional mortar compositions for cross-sectional recovery have a phenomenon in which the adhesive strength decreases due to the difference between the structure, the thermal expansion coefficient, and the elastic modulus, resulting in peeling and peeling off of the structure. There was a problem.

On the other hand, the Republic of Korea Patent No. 10-0474665, registered in 2005 in order to solve the above problems through the surface treatment to remove the deteriorated portion of the concrete and remove foreign matters through the application of the surface reinforcement mortar for the cross-sectional recovery A technology consisting of coating and finishing with ceramic coating has been proposed. In Korea Patent No. 10-0643524, mortar which recovers concrete corroded by neutralization, East Sea, salt sea and alkali is used for general portland cement and silicon dioxide (SiO _2). ) And a silicate compound and metal in an aqueous solution in which a solid component of mortar is made of a finely divided inorganic curing accelerator and sand containing at least 90% of aluminum oxide (Al ₂ O ₃ ) and dissolved in an organoalkoxy silane or an organo carboxy silane. Section Recovery Using Kneading Mortar with Aqueous Solution Adjusted to pH 11 ~ 12 Containing Oxide It was not. However, common components of these compositions include cement, fine calcium carbonate powder, slag fine powder, swelling agent, gypsum and sand, and various resins or dispersants, air entrainers, fibers and antimicrobial agents have been added to maintain functionality. This situation is not being put to practical use.

The present invention is an adhesive strength due to the difference in thermal expansion coefficient and elastic modulus of the mortar composition used for repair or reinforcement and existing concrete, which is a general problem of the above-described conventional reinforcement mortar composition and its reinforcement method. The purpose of the present invention is to solve a phenomenon in which a phenomenon of peeling and peeling off from the structure and the time elapsed and leakage due to cracking and lifting occurs.

That is, the mortar composition of the present invention contains ultrafine portland cement and prompt cement as main components to increase the super hard diameter, ultra high strength, and corrosion resistance, and to inhibit cracking by increasing the durability, water tightness, and adhesiveness using sepiolite and fiber reinforcement materials. By using slag and garnet to improve durability and chemical resistance, it is intended to make the concrete matrix, thermal expansion coefficient, elastic modulus, etc. almost the same.

By repairing and reinforcing the concrete structure using the mortar as described above, by securing a thermal expansion coefficient and elastic modulus similar to the concrete structure to prevent the peeling and peeling from the structure by increasing the adhesive strength and improved durability, by using an acrylic modified epoxy-based primer, Its purpose is to prevent and repair leaks and lifting due to cracking.

The inorganic polymer cement mortar composition for reinforcing and reinforcing the concrete structure of the present invention for achieving the above object is characterized in that it comprises a portland cement, silica sand, a prompt cement, slag and garnet.

And it is characterized in that it comprises 100 parts by weight of the Portland cement, 80 to 100 parts by weight of silica sand, 2 to 15 parts by weight of the prompt cement, 15 to 40 parts by weight of slag and 5 to 12 parts by weight of garnet.

And 0.5 to 4.0 parts by weight of sepiolite, 0.05 to 0.85 parts by weight of curing accelerator, 0.5 to 3.5 parts by weight of fiber reinforcement, 12 to 18 parts by weight of aluminite-based expander, 1.5 to 6.0 parts by weight of fluidizing agent, and 4.5 to 7.5 weight of reemulsified powder resin. It further comprises one or two or more selected from the group consisting of parts.

And the Portland cement is characterized in that the particle size of 20 ~ 90㎛.

In addition, the reinforcement method according to the present invention comprises the steps of chipping and cleaning the deteriorated reinforced concrete structure, the step of applying the anti-rust reducing agent to the rebar of the chipped and cleaned concrete structure, and the reinforcing steel and concrete structure coated with the anti-rust reducing agent And applying a primer to the primer, and pouring the inorganic polymer cement mortar composition onto the primer.

The anti-rust reducing agent is characterized in that the composition is composed of a nitrite lithium salt and silane.

And the primer is composed of 100 parts by weight of acrylic modified epoxy resin, 40 to 75 parts by weight of modified aliphatic amine, 2 to 6 parts by weight of reaction accelerator, 6 to 15 parts by weight of flow modifier and 2.4 to 9 parts by weight of procement. It features.

According to the present invention, by repairing and reinforcing the concrete structure using a high permeability modified epoxy clock primer and an inorganic polymer cement mortar composition, high strength is exhibited by exhibiting a coefficient of thermal expansion and an elastic modulus almost the same as that of the concrete structure. The cross section can be made small, and the adhesion, abrasion resistance, fatigue resistance, chemical resistance and impact resistance are excellent, and water leakage due to peeling peeling and cracking caused by shrinkage and expansion and recovery of the surface of the concrete structure are prevented and lifted. To provide useful effects.

The present invention is a repair and reinforcement method by recovering the cross-section of the concrete structure, the cross-sectional recovery is the salt peeling, alkali aggregate reaction, East Sea, chemical corrosion, neutralization, such as crack peeling, weakening of the concrete, reinforcing corrosion, lifting, rebar exposure As a repair method for many defects, it is a repair method that partially replaces concrete part.

In addition, the inorganic polymer cement mortar composition for repairing and reinforcing the concrete structure of the present invention and the method for repairing the structure using the same, concrete beams, aqueduct bridge, water and sewage water purification plant, retaining wall, tunnel, underground underground pit, water culvert, drainage culvert, sewage culvert, It can be widely applied to concrete repair facilities, manure treatment facilities and water treatment facilities affected by harmful gases, national roads and bridge buildings in coastal or inland areas.

First, the inorganic polymer cement mortar composition for reinforcement of concrete structures used in the present invention will be described.

The inorganic polymer cement mortar composition for reinforcing and reinforcing the concrete structure may include portland cement, silica sand, prompt cement, slag and garnet.

The portland cement is preferably used as the main component of the cement mortar composition having a particle size of 20 ~ 90㎛. This is to limit the particle size of the portland cement, to increase the super speed, ultra-high strength, corrosion resistance, and to have the same behavior as the concrete structure. Hereinafter, the composition ratio of the inorganic polymer cement mortar composition is based on 100 parts by weight of the portland cement.

The silica sand is used as an aggregate, and a weight ratio of 9: 9 to 8: 7 is used in a ratio of 2: 1: 2 to form a common material. Limiting the size of the silica sand is to improve the workability and to reduce cracks, but is not necessarily limited. The silica sand is used as much as 80 to 100 parts by weight in the mortar composition, because if the composition ratio is small, the action is insignificant, and if excessive, the physical properties of the mortar can be lowered.

The cementite has excellent watertightness with ultra-high hardness, high strength and high powder density, and is used to enhance durability with silica sand and to have the same behavior as concrete structures with portland cement. will be. Since the prompt cement is used in the mortar composition as much as 2 to 15 parts by weight, the composition ratio is small because the durability strengthening action is insignificant, and when excessive, the physical properties of the mortar can be lowered.

And the slag (slag) to act as a shrinkage reducing agent, to enhance the durability. The slag has a particle size of about 1 to 140 μm, specific gravity of about 1.9 to 2.3, and the shape of the slag is mostly spherical. The slag is used by 15 to 40 parts by weight in the mortar composition, because if the amount of the slag used is small or large, the physical properties of the mortar is reduced.

The garnet (garnet, particle size 5 ~ 7μm, hardness 7.5) is a high hardness to improve the adhesion, and to increase the strength, wear resistance and durability close to the concrete, the garnet is used in 5 to 12 parts by weight in the mortar composition If the usage of the garnet is small or large, the adhesion, wear resistance, etc. are not good.

That is, as described above, the inorganic polymer cement mortar composition for reinforcing and reinforcing the concrete structure according to the present invention is made of ultra fine particles of portland cement, silica sand, prompt cement, slag and garnet, thereby having the same behavior as that of the concrete structure. will be.

On the other hand, the inorganic polymer cement mortar composition for the reinforcement of the concrete structure further comprises one or two or more selected from the group consisting of sepiolite, curing accelerator, fiber reinforcement, aluminite-based expanding agent, fluidizing agent, re-emulsified powder resin. If it can be, further comprising the above composition can improve the adhesion, workability, strength and the like.

First, the sepiolite (Sepiolite) is an inorganic thickener, it generates hydrate crystals during the hydration reaction of cement to improve the durability, water tightness and high strength, to suppress cracks, to improve the adhesion to concrete and the absorbency and fluidity By improving the workability by expression, it is possible to obtain an air shortening effect. Sepiolite is used by 0.5 to 4.0 parts by weight in the mortar composition, because the use is small, the effect is insignificant, and if excessive, rather it may lower the physical properties of the mortar composition.

The curing accelerator is for promoting the curing rate of the mortar composition, and as the curing accelerator, for example, calcium carbonate may be used, but is not necessarily limited thereto. The curing accelerator is used by 0.05 to 0.85 parts by weight in the mortar composition, because if the amount is small it may not promote the curing, but if excessive, may lower the physical properties of the mortar composition.

Polypropylene fiber may be used as the fiber reinforcing material, and the fiber reinforcing material is to prevent cracking and diffusion of cracks and cracks of concrete and mortar, and has excellent energy absorption ability to exert excellent bending toughness effect to improve durability. It is to reduce the deflection during construction and to enhance the adhesion and cohesive effect. The fiber reinforcing material is used by 0.5 to 3.5 parts by weight in the mortar composition, because if the use is less, the crack resistance is lowered, if excessive, may cause problems in dispersion in the mortar.

The aluminite-based (CSA) expanding agent forms a stable and dense structure in the long term while filling the micro voids in concrete, which is effective in improving the watertightness of the concrete and increasing the stable strength of the structure, and at the same time, the change of the material according to the temperature change. Since it hardly appears, there is an effect of preventing the adhesive force degradation and peeling phenomenon due to the temperature change. In the present invention, the mixture of aurin and calcium oxide may be used as the aluminite-based expander, but the present invention is not limited thereto, and the aluminite-based expander does not limit its type. The aluminite-based (CSA) expanding agent is used by 12 to 18 parts by weight in the mortar composition, because if the use is small, the effect is insignificant, and if excessive, may cause cracking in the mortar by excessive expansion.

The fluidizing agent may be used in the naphthalene-based, it is to increase the fluidity of the mortar to reduce the unit amount by 20 ~ 30% to reduce the material cost and increase the strength. The fluidizing agent is used in the mortar composition as much as 1.5 ~ 6.0 parts by weight, if the use is small, the material cost reduction and the strength of the effect is not increased, if excessive, the fluidity becomes too large, adhesion is reduced, as well as curing This is because there is a delay problem.

The re-emulsified powder resin is used as a polymer, and complements the solidification time, small tensile strength, large dry shrinkage, low chemical resistance, etc. to increase the adhesion between the aggregate, that is, silica sand and cement paste, deformation period of the concrete member It can absorb more fracture energy in the meantime. In addition, since it penetrates into the micro-pore, the effect of combining the hydrated cement with the unhydrated cement can be obtained, and after curing, high strength is expressed early, and the cross section of the member can be made small due to the high strength. Adhesion and wear resistance, fatigue resistance, chemical resistance and impact resistance are excellent. As the re-emulsified powder resin, ethyl vinyl acetate powder resin or SBR powder resin may be used. The re-emulsified powder resin is used in the mortar composition as much as 4.5 to 7.5 parts by weight, because the amount is small, the effect is insignificant and the excess is not economical.

In addition, if necessary, a admixture may be used. The admixture may be a silica fume-based one. The admixture reduces cracks due to hydration heat, increases fire resistance, and achieves high strength to provide excellent weather resistance and chemical resistance in the long term. In addition, it is possible to secure excellent adhesion due to the admixture, and it is possible to construct up to 20cm in thickness at one time for other spraying work, and the rebound amount is less than 5% at the time of work, so the dropout rate is small and the work time is shortened by the connection of continuous process. You can. Since the admixture is used in the range of 0.6 to 4.0 parts by weight in the mortar composition, it is difficult to increase the fire resistance when the amount thereof is used in a small amount.

As described above, the inorganic polymer cement mortar composition of the present invention has a compressive strength of about 472 kgf / cm 2, a flexural strength of about 85 kgf / cm 2, a tensile strength of about 47 kgf / cm 2, and an adhesive strength of about 32 kgf / cm 2.

As described above, the inorganic polymer cement mortar composition according to the present invention is non-toxic and environmentally friendly, and can be variously constructed, such as a spraying method, a plastering method, a concrete pouring method, etc., and thus easy construction, heat resistance, fire resistance, thermal expansion coefficient, elastic modulus The characteristic value of the structure is similar to that of the concrete structure, so that no abnormal behavior due to the structure behavior does not occur, thereby causing damage to the structure such as peeling peeling and cracking.

That is, the mortar composition of the present invention is to enhance the durability by the use of the prom cement, silica sand, slag, the use of garnet and aluminite-based expansion agent to improve the adhesion and strength, durability and wear resistance, ultra-fine particle portland cement The use of and slag to compensate for the deflection of mortar during construction, and the use of sepiolite, slag, aluminite-based expansion agent to increase the water-tightness, durability, rigidity of the concrete and to strengthen the adhesion to suppress cracks.

Hereinafter will be described the repair and reinforcement method of the concrete structure according to the present invention.

As a first step, the degraded reinforced concrete structures are chipped and cleaned. Since the chipping and cleaning method of the reinforced concrete structure is well known in the art to which the art belongs, a detailed description thereof will be omitted.

Next, the antirust agent is applied to the rebar of the chipped and cleaned concrete structure. Here, as the anti-rust reducing agent, a lithium nitrite salt and silane (SiH ₄ ) are used, and the anticorrosive reducing agent formed of the lithium nitrite salt and the silane is applied with a brush or a roller, so that the corroded rebar surface is prevented from rust reducing and It is the way.

And by applying the primer to the concrete structure damaged by the deterioration of the rebar and the rust-reducing agent is applied, it prevents the progress of deterioration and expresses the initial strength. Here, as the primer, a modified epoxy clock primer is used. Specifically, the modified epoxy clock primer includes an acrylic modified epoxy clock resin, a modified aliphatic amine, a reaction accelerator, a flow modifier, and a prompt cement. The composition is based on 100 parts by weight of the acrylic modified epoxy resin, 40 to 75 parts by weight of modified aliphatic amine, 2 to 6 parts by weight of reaction accelerator, 6 to 15 parts by weight of flow modifier and procement 2.4 ˜9 parts by weight is mixed, preferably made of a liquid phase. Here, as the reaction accelerator, a modified aliphatic amine curing agent may be used, and a naphthalene system may be used as the flow adjusting agent, but is not necessarily limited thereto.

Here, the prompt cement has excellent watertightness with ultrafast diameter, ultra high strength, and high powder density, and improves seawater condensation, corrosion resistance, and chemical resistance of the primer, and serves to suppress deterioration damage due to the behavior of concrete structures by enhancing adhesion. . In addition, the reaction promoter and the flow modifier are added to the composition ratio according to the season and temperature change, thereby increasing the permeability and initial expression strength, and the prophylment is added and added to the composition ratio, so that sodium chloride and magnesium sulfate It gives strong corrosion resistance and chemical resistance to, and improves workability and durability.

The modified epoxy clock primer has a low viscosity of 4000 ~ 6000 (25 ℃, cps) is good flow and penetrates to the depth of 3 ~ 15mm of the concrete structure to increase the adhesive strength and durability, since the adhesive strength is more than 20kgf / ㎠ Since there is no peeling, peeling or lifting after recovery, and the tensile elongation is 10% or more, it is possible to prevent cracking and lifting due to deterioration due to the behavior of the structure.

In addition, since the primer according to the present invention does not add a volatile viscosity modifier or diluent, environmentally-friendly cured products are being constructed, the tensile strength is 470kgf / ㎠ or more, the adhesive strength 20kgf / ㎠ or more excellent mechanical properties and elongation of 10% or more It minimizes dry shrinkage and expansion cracks according to the behavior of the structure to prevent peeling peeling and catches leakage and lifting due to cracking.

When the application of the primer is complete, the inorganic polymer cement mortar composition is next poured on the primer. Since the inorganic polymer cement mortar composition has been sufficiently described above, a description thereof will be omitted.

And when the casting of the inorganic polymer cement mortar composition is completed and the cross section is restored, it is to finish with a water repellent or waterproof coating as needed.

As described above, the present invention has been described by the above embodiments, but various modifications can be made without departing from the scope and spirit of the present invention.

Claims (9)

In constructing a cement mortar composition for reinforcement of concrete structures,
100 parts by weight of Portland cement, 80 to 100 parts by weight of silica sand, 2 to 15 parts by weight of prompt cement, 15 to 40 parts by weight of slag, 5 to 12 parts by weight of garnet,
Sepiolite 0.5 to 4.0 parts by weight, curing accelerator 0.05 to 0.85 parts, fiber reinforcement 0.5 to 3.5 parts by weight, aluminite-based expansion agent 12 to 18 parts by weight, fluidizing agent 1.5 to 6.0 parts by weight and re-emulsified powder resin 4.5 to 7.5 parts by weight Inorganic polymer cement mortar composition for reinforcement of a concrete structure, characterized in that it further comprises one or more selected from the group consisting of. delete delete delete The method of claim 1,
The portland cement is an inorganic polymer cement mortar composition for reinforcement of a concrete structure, characterized in that the particle size of 20 ~ 90㎛. Chipping and cleaning the degraded reinforced concrete structure,
Applying an antirust agent to the rebar of the chipped and cleaned concrete structure;
Applying a primer to the reinforcing bar and concrete structure to which the rust-reducing agent is applied;
Comprising the step of pouring the inorganic polymer cement mortar composition of any one of claims 1 and 5 on the primer,
The primer is an acrylic modified epoxy resin, modified aliphatic amines, reaction accelerators, flow modifiers and prophylment, characterized in that the reinforcement method of the concrete structure. The method according to claim 6,
The anti-rust reducing agent is a repair and reinforcement method of a concrete structure, characterized in that composed of a nitrite-based lithium salt and silane. delete The method according to claim 6,
The primer comprises 100 parts by weight of acrylic modified epoxy resin, 40 to 75 parts by weight of modified aliphatic amine, 2 to 6 parts by weight of reaction accelerator, 6 to 15 parts by weight of flow modifier, and 2.4 to 9 parts by weight of prompt cement. Repair reinforcement method of concrete structure.