KR102414798B1 - Crack reducing salt resistance mortar composition having excellent thixotropy and repairing and reinforcing method using the same - Google Patents

Abstract

The present invention relates to a crack-reducing flame-resistant polymer mortar composition with excellent thixotropy containing a thickener consisting of a mixture of a cellulosic organic thickener and sepiolite, a porous inorganic thickener, a powder-type high fluidizing agent, and a moisturizing material, and a cross-section repair and reinforcement method using the same More specifically, sepiolite, a porous inorganic thickener, is used to absorb moisture from the existing concrete sewer pipe to prevent sagging that occurs at the beginning of pouring, and sacran and sodium hyaluronate (moisturizing material) are used simultaneously to mortar during plastering work. It is possible to express excellent workability by reducing the frictional force with, and the moisturizing material further contains sodium chloride to provide a crack-reducing flame-resistant polymer mortar composition with excellent thixotropic properties and a cross-section repair and reinforcement method using the same.

Description

A crack-reducing flame-resistant polymer mortar composition with excellent thixotropy and a cross-section repair and reinforcement method using the same

The present invention relates to a crack-reducing flame-resistant polymer mortar composition with excellent thixotropy containing a thickener consisting of a mixture of a cellulosic organic thickener and sepiolite, a porous inorganic thickener, a powder-type high fluidizing agent, and a moisturizing material, and a cross-section repair and reinforcement method using the same will be.

Reinforced concrete structures deteriorate due to salt damage, neutralization, alkali aggregate reaction, and chemical corrosion, as well as corrosion and expansion of steel materials due to water penetration after construction. If the deterioration of these structures continues, there is a risk of eventually leading to the collapse of the structures, so it is necessary to continuously manage and repair them.

Separation of the structure surface or the occurrence of initial defects or cracks facilitates the movement of deterioration factors and accelerates deterioration. and to improve durability.

Therefore, after removing the concrete part containing deterioration factors such as delamination or drop-off of the cross section of the structure due to deterioration of concrete, corrosion of steel, or other causes, fill or spray with repair reinforcement material to restore the cross section to its original performance and shape. It is common to carry out repairs after construction.

The conventional repair materials for repair and reinforcement have mainly used cement-based mortar or polymer cement mortar. These conventional repair materials have the purpose of suppressing the deterioration of the existing structure and improving the durability performance beyond the present. Most of them focused only on improving the adhesion performance, so there was a problem that the surface had to be repaired frequently because the surface was easily damaged again shortly after construction.

On the other hand, in the repair of a concrete structure, workability is rapidly lost after pouring due to the influence of direct sunlight and outside air, and it is difficult to obtain a predetermined working time. This problem was solved through excessive hydrolysis, which caused the methyl cellulose-based thickener to affect the thixotropic properties of the polymer mortar, leading to sagging of the material, which in turn leads to plastic shrinkage and thus cracks. Microcracks that occurred at the beginning of the work are exposed to calcium chloride and various deterioration factors used on the road, resulting in a significant decrease in the durability of the concrete structure.

In the past, many excellent salt-resistant concrete repair mortars and methods have been developed in this environment, but in general, an acid-based retardant is used to improve the working environment of concrete structures exposed to the outside, so it is improved as a method of securing working time. Although it is common to try to do this, it delays the hydration reaction of the polymer mortar, thereby impairing the mechanical properties of the final cured product.

Therefore, there is a need for a mortar material and a repair and reinforcement method for preventing flow and sagging due to an acid-based retardant used due to excessive drying in construction, as well as strong salt resistance to chemical erosion.

Korean Patent No. 10-1844193

In order to solve the above problems, the present invention provides a crack-reducing salt-resistant polymer mortar composition with excellent thixotropy containing a thickener, a powder-type high fluidizer and a moisturizing material, comprising a mixture of a cellulose-based organic thickener and sepiolite, a porous inorganic thickener, and It is intended to provide a cross-section repair and reinforcement method using this.

According to an embodiment of the present invention, 100 parts by weight of a binder, 80 to 200 parts by weight of silica sand, 0.1 to 5.0 parts by weight of a moisturizing material, 10 to 50 parts by weight of a polymer, 0.5 to 2.0 parts by weight of a shrinkage inhibitor, 2 to 40 parts by weight of a filler , 0.1 to 1.0 parts by weight of an antifoaming agent, 5 to 20 parts by weight of a swelling agent, 0.1 to 10 parts by weight of a curing accelerator, 0.2 to 20 parts by weight of a glidant, 2 to 20 parts by weight of a thickener, 0.1 to 1.0 parts by weight of a retardant, and 0.1 to an alkali active agent A crack-reducing flame-resistant polymer mortar composition with excellent thixotropy comprising 2.0 parts by weight, wherein the binder comprises 20 to 50% by weight of crude Portland cement and 50 to 80% by weight of alumina cement, wherein the alumina cement is calcium alumina Nate (Calcium Aluminate, CA) and amorphous calcium aluminate, C ₁₂ A ₇ , any one or more selected from the group consisting of, the moisturizing material is sodium hyaluronate (Sodium hyaluronate) and sacran (Sacran) in a 1:1 weight ratio, the The thickener consists of a mixture of a cellulose-based organic thickener and sepiolite, which is a porous inorganic thickener, and the polymer is made of at least one of EVA (Ethylene-vinyl acetate) resin, acrylic re-emulsifying resin, and SBR (Styrene Butadiene Rubber), the The anti-shrink agent is made of neopentyl glycol, the filler is made of any one or more of silica fume, blast furnace slag, and fly ash, and the expanding agent is calcium sulfoaluminate (CSA), anhydrite, phosphate gypsum and Any one or more of hydrofluoric acid gypsum, the curing accelerator is made of at least one selected from sodium silicate, lithium carbonate, and lithium sulfate, the fluidizing agent is any one or more of polycarboxylic acid-based and naphthalene-based, and the retarder is Any one or more of citric acid, tartaric acid, and gluconic acid, and the alkali activator is KOH, NaOH, and CaOH ₂ Provided is a crack-reducing flame-resistant polymer mortar composition having excellent thixotropic properties.

The moisturizing material further includes sodium chloride as a thixotropic enhancer, and the sodium chloride is characterized in that it is included in an amount of 1.0 to 5.0 parts by weight based on 100 parts by weight of the moisturizing material.

The thickener is characterized in that the cellulose-based organic thickener and the porous inorganic thickener, sepiolite, are included in a 1:1 content ratio.

According to another embodiment of the present invention, a first step of removing the deteriorated portion of the concrete structure and removing foreign substances and then cleaning the surface of the deteriorated portion in a dry manner using a high-pressure air compressor; A second step of applying an alkali recovery agent to the surface-cleaned concrete structure and applying a rust preventive coating agent to the exposed reinforcing bars; a third step of applying the crack-reducing flame-resistant polymer mortar composition having excellent thixotropy to the surface to which the alkali recovery agent is applied and the anti-rust coating agent is applied; and a fourth step of applying a surface protection agent after the mortar composition for repair and reinforcement is applied.

According to one embodiment of the present invention, it is possible to provide a mortar composition excellent in salt resistance by minimizing the generation of portlandite that combines with carbon dioxide to produce calcium hydroxide weak to acid.

In addition, unlike the conventional mechanism of creating a tight hardening body by simply filling the pores of the mortar with resin, the flame resistance of the mortar binder can be fundamentally increased, and direct sunlight and windy By using sepiolite, a porous inorganic material, for sagging caused by excessive rheological properties of mortar in a poor environment, cracks can be prevented from sagging through initial sagging.

In addition, it is possible to provide a mortar composition for repairing concrete structures having excellent workability while insensitive to water rain by using sacran, a high-functional moisturizing material, in workability that may become somewhat stiff due to the use of sepiolite.

In particular, according to one embodiment of the present invention, sacran as a moisturizing material can retain about 5 to 10 times more moisture than hyaluronic acid, and by adding Sacran as the moisturizing material , even if the content of the other work performance improving agent is reduced, workability can be more excellently improved, and the effect of reducing shrinkage can be excellent.

In addition, when the moisturizing material contains sacran and sodium hyaluronate in a 1:1 content ratio, the workability improvement effect is excellent and the shrinkage reduction effect is excellent.

In addition, as another embodiment of the present invention, the moisturizing material contains sacran and sodium hyaluronate in a 1:1 content ratio, and at the same time, sodium chloride as a thixotropic enhancer is added to 100 parts by weight of the moisturizing material. , by including in an amount of 1.0 to 5.0 parts by weight, there is an excellent advantage that can improve the workability and fluidity by improving the thixotropic properties of the mortar composition for repairing concrete structures.

1 is a photograph of the results of testing the crack resistance according to Examples and Comparative Examples of the present invention.

Hereinafter, the present invention will be described in more detail through Examples and Experimental Examples. However, these examples are only for helping the understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

According to an embodiment of the present invention, 100 parts by weight of a binder, 80 to 200 parts by weight of silica sand, 0.1 to 5.0 parts by weight of a moisturizing material, 10 to 50 parts by weight of a polymer, 0.5 to 2.0 parts by weight of a shrinkage inhibitor, 2 to 40 parts by weight of a filler , 0.1 to 1.0 parts by weight of an antifoaming agent, 5 to 20 parts by weight of a swelling agent, 0.1 to 10 parts by weight of a curing accelerator, 0.2 to 20 parts by weight of a glidant, 2 to 20 parts by weight of a thickener, 0.1 to 1.0 parts by weight of a retarder, and 0.1 to an alkali active agent Provided is a crack-reducing flame-resistant polymer mortar composition having excellent thixotropy comprising 2.0 parts by weight.

The binder includes 20 to 50% by weight of crude portland cement and 50 to 80% by weight of alumina cement, and the alumina cement is selected from calcium aluminate (CA) and C ₁₂ A ₇ which is amorphous calcium aluminate. at least one, and the moisturizing material contains sodium hyaluronate and sacran in a 1:1 weight ratio, and the thickener consists of a mixture of a cellulose-based organic thickener and sepiolite, which is a porous inorganic thickener, and the polymer is made of at least one of EVA (Ethylene-vinyl acetate) resin, acrylic re-emulsifying resin, and SBR (Styrene Butadiene Rubber), the anti-shrinkage agent is made of neopentyl glycol, and the filler is silica fume, blast furnace slag and fly. Consists of any one or more of ash, and the expanding agent is any one or more of calcium sulfoaluminate (CSA), anhydride, phosphate gypsum, and hydrofluoric acid gypsum, and the curing accelerator is sodium silicate, lithium carbonate and lithium sulfate. It consists of at least one selected from among, the fluidizing agent is any one or more of polycarboxylic acid and naphthalene, the retarder is any one or more of citric acid, tartaric acid, and gluconic acid, and the alkali active agent is KOH, NaOH and It is characterized in that at least one of CaOH ₂ .

The crack-reducing flame-resistant polymer mortar composition excellent in thixotropy according to an embodiment of the present invention includes 100 parts by weight of a binder, wherein the binder includes 20 to 50% by weight of crude Portland cement and 50 to 80% by weight of alumina cement .

In one embodiment of the present invention, the binder includes 20 to 50% by weight of crude portland cement and 50 to 80% by weight of alumina cement, so that crude strength is secured through rapid formation of initial etrinzite, and alumina cement By using it, it is possible to relatively decrease the acid-sensitive C ₂ S and C ₃ S compounds, and increase the C ₃ A compounds.

The alumina cement is characterized in that at least one selected from calcium aluminate (Calcium Aluminate, CA) and amorphous calcium aluminate C ₁₂ A ₇ .

According to one embodiment of the present invention, the alumina cement may be any one of calcium aluminate (Calcium Aluminate, CA) and amorphous calcium aluminate C ₁₂ A ₇ .

In particular, when the alumina cement uses calcium aluminate (CA) and C ₁₂ A ₇ , which is an amorphous calcium aluminate, in a 1:1 content ratio at the same time, not only the flame resistance but also the crack resistance effect can be more excellent. have.

The crack-reducing flame-resistant polymer mortar composition excellent in thixotropy according to an embodiment of the present invention includes 80 to 200 parts by weight of silica sand, and it is preferable to use fine sand having an average particle diameter of 0.1 to 1.2 mm, which is a mortar. This is to improve the fluidity and compactness of the composition.

According to one embodiment of the present invention, the thickener consists of a mixture of a cellulose-based organic thickener and sepiolite, which is a porous inorganic thickener.

In one embodiment of the present invention, the thickener is characterized in that it comprises 2 to 20 parts by weight of a thickener mixture in which a cellulose-based organic thickener and sepiolite, which is a porous inorganic thickener, are mixed.

In this case, the cellulose-based thickener is preferably selected from methyl-based cellulose, ethyl-based cellulose, and propyl-based cellulose.

The thickener according to an embodiment of the present invention is characterized in that it does not use only an organic thickener, unlike the conventional mortar composition, but uses a mixture of a cellulose-based thickener and sepiolite, a porous inorganic thickener.

Most of the repair mortars used in the existing sewage pipe repair method are designed to have excellent flame resistance by using polymer materials such as EVA and SBR. , and this may cause cracks before hardening of the mortar, thereby weakening the durability.

In particular, when only an organic thickener is used as a thickener, the rheological properties of the mortar are increased, resulting in sagging of the mortar, which causes cracks before hardening of the mortar, thereby increasing the possibility of weakening durability.

However, according to one embodiment of the present invention, since the thickener is made of a mixture of a cellulose-based organic thickener and sepiolite, which is a porous inorganic thickener, sagging caused by the rheological properties of the mortar that is inevitably generated by using the resin is reduced. It can be prevented by using sepiolite, which is a porous inorganic material, and cracks can be prevented from sagging through the initial pouring.

The thickener is characterized in that the cellulose-based organic thickener and the porous inorganic thickener, sepiolite, are included in a 1:1 content ratio. When the cellulose-based organic thickener and the porous inorganic thickener, sepiolite, are included in a 1:1 content ratio, it is possible to prevent sagging of the mortar, which is unavoidably caused by using the resin, and thus the effect of inhibiting cracking through initial sagging during pouring is better can do.

The crack-reducing flame-resistant polymer mortar composition with excellent thixotropic properties according to an embodiment of the present invention includes 0.1 to 5.0 parts by weight of a moisturizing material, and the moisturizing material may become somewhat stiff due to the use of the porous inorganic thickener, Sepiolite. Workability can improve

In particular, the moisturizing material includes sacran, and by using the high-functional moisturizing material, sacran, it is insensitive to water rain in an environment exposed to direct sunlight and wind, and provides a mortar composition for repairing concrete structures with excellent workability can do.

As the moisturizing material, sacran is a material with very water-retaining power, and is an agar material that covers Suizenji nori, a single-celled organism, and consists of a linear sugar mass (polysaccharide) such as starch.

In particular, the molecular weight of the sacran (Sacran) is 16 million, and shows a moisturizing power of 5 times or more compared to that of hyaluronic acid, which has excellent moisturizing properties.

According to an embodiment of the present invention, the crack-reducing flame-resistant polymer mortar composition with excellent thixotropy includes sacran as a moisturizing material, so that it may become somewhat stiff due to the use of sepiolite, a porous inorganic thickener, as described above. workability can be improved.

In general, it is already known that the use of superabsorbent polymer makes the structure of the hardener more rigid and dense by holding moisture in the structure during the hydration process of cement mortar and slowly providing the necessary moisture during hydration.

However, when the superabsorbent polymer is used alone, the rheology of the mortar is increased, which may lead to sagging, and this has a material limitation in that it may cause an initial crack.

However, as described above, according to one embodiment of the present invention, sepiolite, a porous inorganic thickener, is an inorganic material having porosity due to a hollow structure. At the same time, it is possible to reduce friction with a plastering trowel used at the time of work by creating a water film phenomenon, thereby greatly improving workability, and there is an advantage that the superabsorbent polymer can be used in a sufficient amount.

According to an embodiment of the present invention, the moisturizing material further comprises sodium hyaluronate (Sodium hyaluronate), and the sacran (Sacran) and the sodium hyaluronate (Sodium hyaluronate) are characterized in that they are included in a 1:1 content ratio. do.

When the moisturizing material contains sacran and sodium hyaluronate in a 1:1 content ratio, economic efficiency may be more excellent, and workability that may become somewhat stiff due to the use of the porous inorganic thickener sepiolite can improve

In particular, it is possible to provide a mortar composition for repairing concrete structures having excellent workability by maintaining excellent moisture retention while insensitive to water rain in an environment exposed to direct sunlight and wind.

According to one embodiment of the present invention, the moisturizing material contains sacran and sodium hyaluronate in a 1:1 content ratio, and at the same time, sodium chloride as a thixotropic enhancer is added to 100 parts by weight of the moisturizing material, It is characterized in that it further comprises in an amount of 1.0 to 5.0 parts by weight.

The moisturizing material contains sacran and sodium hyaluronate in a 1:1 content ratio, and at the same time, sodium chloride as a thixotropic enhancer is included in an amount of 1.0 to 5.0 parts by weight based on 100 parts by weight of the moisturizing material. , there is an excellent advantage that can improve workability and fluidity by improving the thixotropic properties of the mortar composition for repairing concrete structures.

Here, the fluidity of the cement composition is a term that comprehensively expresses the workability of mortar, fluidity in transport or equipment, water retention, stability against material separation, compaction, and plastering properties. This can be said to be the relationship between stress and strain. Therefore, according to an embodiment of the present invention, the moisturizing material contains sacran and sodium hyaluronate in a 1:1 content ratio, and at the same time, sodium chloride as a thixotropic enhancer is added to 100 parts by weight of the moisturizing material. , by including in an amount of 1.0 to 5.0 parts by weight, it is possible to improve the fluidity of the mortar by improving the thixotropic properties of the cement composition without deterioration of mechanical properties, and consequently, it is possible to improve the workability of the mortar.

When sodium chloride as the thixotropic enhancer is included in an amount of less than 1.0 parts by weight based on 100 parts by weight of the moisturizing material, there is no thixotropic enhancing effect of the mortar, so the workability improvement effect of the mortar composition for repairing concrete structures may be insufficient.

On the other hand, when sodium chloride as the thixotropy enhancer is included in excess of 5.0 parts by weight with respect to 100 parts by weight of the moisturizing material, sodium chloride may be included in excess and may adversely affect the corrosion of reinforcing bars. As a mortar composition for repairing concrete structures, it may adversely affect concrete structures.

The polymer includes any one or more of ethylene-vinyl acetate (EVA) resin, acrylic re-emulsification resin, and SBR (Styrene Butadiene Rubber).

The polymer serves to increase fluidity and improve workability in the state before curing of the mortar composition, and to increase surface adhesion, increase cohesion, increase flexural strength, increase flexibility, and increase waterproofing in the state after curing of the mortar composition. perform

In the present invention, the acrylic re-emulsification resin increases water resistance and adhesion, and it is preferable to use a re-emulsification resin prepared by a special manufacturing method.

Specifically, the acrylic re-emulsification resin may include: 100 parts by weight of a total monomer comprising 80 to 90% by weight of an acrylic polymer and 10 to 20% by weight of a monomer having a crosslinkable functional group; 0.1-5 parts by weight of reactive anionic emulsifier and nonionic emulsifier; Polymerization initiator 0.01 to 1 part by weight; and an acrylic emulsion polymer obtained by polymerization of a pre-emulsion containing 45 to 50 parts by weight of water.

More specifically, the acrylic polymer is methyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexylacrylate, and 2-hydroxy hexyl. Acrylate (2-hydroxy hexylacrylate), acrylonitrile (acrilonitrile), dimethylaminoethylmethacrylate (dimethylaminoethylmethacrylate), acetoacetoxy ethyl methacrylate, divinyl benzene (divinyl benzene), ethylene glycol Recall ethylene glycol dimethacrylate, butanediol dimethacrylate, cyclo hexyl metharylate, 3-chloro-2-hydroxypropyl methacrylate (3-chloro-2- A copolymer such as hydroxy-propyl methacrylate) may be used.

In addition, the monomer having a crosslinkable functional group is methacryloxypropyltrimethoxysilane, acrylonitrile, acetoacetic ethyl methacrylate, divinylbenzene, ethylene glycol dimethacrylate, butanediol dimethacrylate, cyclohexyl It is preferable that it is 1 type or a mixture of 2 or more types selected from methacrylate and 3-chloro-2-hydroxypropyl methacrylate.

The reactive anionic emulsifier may use polyoxyethylene nonylphenyl ether ammonium sulfate, and the nonionic emulsifier includes alkyl polyethoxy acrylate, alkyl polyethoxy methacrylate, aryl poly Ethoxy acrylate (aryl polyethoxy acrylate), aryl polyethoxy methacrylate (aryl polyethoxy methacrylate), etc. may be used.

The polymerization initiator may include ammonium persulphate (APS), potassium persulfate (KPS), sodium persulfate (SPS), sulfoxylate, t-butyl hydroperoxide, and the like.

The acrylic re-emulsification resin may include: 100 parts by weight of a total monomer comprising 80 to 90% by weight of an acrylic polymer and 10 to 20% by weight of a monomer having a crosslinkable functional group; 0.1-5 parts by weight of reactive anionic emulsifier and nonionic emulsifier; 0.01 to 1 part by weight of a polymerization initiator; and an acrylic emulsion polymer obtained by polymerization of a pre-emulsion containing 45 to 50 parts by weight of water.

The acrylic re-emulsification resin is prepared in a pre-emulsion state by mixing a reactive anionic emulsifier and a non-ionic emulsifier with an acrylic copolymer and a monomer having a crosslinkable functional group and water, and then maintaining the temperature at about 70 to 90 ° C. Up to about 10% by weight of the initial polymerization reaction is carried out. Then, the remaining amount of the pre-emulsion and the polymerization initiator are administered to the reaction material over about 5 to 10 hours to allow a continuous polymerization reaction, followed by aging for about 30 to 90 minutes. Thereafter, it is possible to prepare an acrylic re-emulsification resin by cooling it after undergoing a post-reaction at about 60°C.

In the present invention, the polymer component preferably has a solid content of 45 to 52%, a pH of 8.0 to 9.5, and a viscosity of 200 to 2000 cps. The thus-prepared polymer may be cooled and sprayed to be pulverized and pulverized together with a filler to prevent re-agglomeration through a pulverization process.

In the present invention, the polymer uses a mixture of EVA resin and special acrylic re-emulsification resin, so workability and water resistance are improved, bending strength, tensile strength and adhesion strength, drying shrinkage resistance, mechanical properties are improved, chemical resistance, freeze-thaw resistance It is possible to maximize durability, including

According to an embodiment of the present invention, it is preferable to use neopentyl glycol as the anti-shrink agent. The neopentyl glycol has two symmetrical alcohol groups and two methyl groups at the alpha carbon position, thereby showing excellent reactivity in the esterification reaction. In the present invention, the neopentyl glycol may be used in the form of a flake composed of 100% white crystals or a slurry composed of 90% neopentyl glycol and 10% water.

The filler is made of any one or more of silica fume, blast furnace slag, and fly ash.

In an embodiment of the present invention, the silica fume is an amorphous active silica as a particle close to a perfectly spherical shape consisting of an average particle diameter of about 0.1 to 0.5 mm, and reacts with calcium hydroxide as in the following formula to react with calcium silicate at room temperature. By changing to , it has super pozzolanic properties.

3CaOS0 ₂ + H ₂ O → CSH (cement gel) + Ca(OH) ₂

The reason for adding the silica fume to the mortar composition in one embodiment of the present invention is to improve water tightness and high strength due to the filling effect of silica fume between cement particles, and to reduce the amount of ground by improving the adhesion of shotcrete and suppress alkali silica reaction. This is because there are effects such as improvement of chemical resistance and the like.

In addition, in one embodiment of the present invention, the fly ash (fly ash) remains in the form of oxides remaining after burning coal in facilities using coal as fuel, such as thermal power plants, silicon oxide (SiO ₂ ) or aluminum oxide (Al ₂ ) O ₃ ) It means the remaining fine dust of the component. When the fly ash is mixed and used, workability is improved, heat of curing is lowered, and long-term strength and watertightness are improved, which is economical.

In addition, in one embodiment of the present invention, the expanding agent is characterized in that at least one of calcium sulfoaluminate (Calcium Sulfo Aluminate, CSA), anhydrite, phosphate gypsum, and hydrofluoric acid gypsum.

Anhydrous gypsum, phosphate gypsum and hydrofluoric acid gypsum serve to enhance high strength, quick setting and expandability together with CSA-based expanding agents, and serve to compensate for the shortcomings of CSA-based expanding agents.

In one embodiment of the present invention, the expanding agent may be prepared by mixing calcium sulfoaluminate (CSA) and gypsum in a weight ratio of 4 to 9: 1 to 6, and the gypsum is anhydrous gypsum, phosphate gypsum and hydrofluoric acid gypsum. You can choose from among them.

In one embodiment of the present invention, the expanding agent is preferably included in the range of 5 to 20 parts by weight in the mortar composition. When the content of the expanding agent is less than 5 parts by weight, the resistance to cracking is reduced, and it exceeds 20 parts by weight. In this case, the reaction speed is increased and the pot life is shortened, so there is a problem of poor workability.

In one embodiment of the present invention, the antifoaming agent is a component used to improve the strength and appearance of the mortar by removing the macropores in the mortar. Generally, an oily substance with low volatility and high diffusion power or a water-soluble surfactant is used. For example, higher alcohols, phosphoric acid esters, silicones, non-aqueous alcohols, etc. may be used.

More specific examples include mineral oil-based antifoaming agents such as kerosene and liquid paraffin; Oil-and-oil-based antifoaming agents such as animal and vegetable oils, sesame oil, castor oil, and their alkylene oxide adducts; fatty acid-based antifoaming agents such as oleic acid, stearic acid and their alkylene oxide adducts; fatty acid ester antifoaming agents such as glycerin monoricinolate, alkenyl succinic acid fluid, sorbitol monolaurate, sorbitol trioleate, and natural wax; Polyoxyalkylenes, (poly)oxyalkyl ethers, acetylene ethers, (poly)oxyalkylene fatty acid esters, (poly)oxyalkylene sorbitan fatty acid esters, (poly)oxyalkylenealkyl (aryl) ether oxyalkylene-based antifoaming agents such as sulfate ester salts, (poly)oxyalkylenealkyl phosphate esters, (poly)oxyalkylenealkylamines, and (poly)oxyalkyleneamide; alcohol-based antifoaming agents such as octyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like; amide-based antifoaming agents such as acrylate polyamines; phosphate ester-based 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.

In one embodiment of the present invention, the curing accelerator promotes curing of the mortar to express initial strength, and for example, one or more selected from sodium silicate, lithium carbonate and lithium sulfate may be used.

In one embodiment of the present invention, the fluidizing agent adsorbs to the particle surface of the mortar and gives an electric charge to the particle surface to generate a mutual reaction force between the particles, so that the agglomerated particles are dispersed to increase the flow to increase the strength due to the water-reducing effect. play a role in making it possible. As the fluidizing agent, for example, melamine selphonic acid, naphthalene selphonic acid, polycarboxylic acid, lignin sulfonic acid, or alkylaryl sulfonic acid fluidizing agents may be used, and more specifically, lignin sulfonate, polynaphthalene sulfonate, and polymelamine sulfonate. It is possible to use alone or a mixture of two or more from the group consisting of nate or polycarboxylate-based water reducing agents.

In particular, since the setting time is affected when the fluidizing agent is used, a setting time adjusting agent may be appropriately included for use.

In one embodiment of the present invention, the fluidizing agent reduces 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, etc. can be applied. have. The fluidizing agent is preferably included in the composition in an amount of about 0.2 to 20 parts by weight.

Further, according to an embodiment of the present invention, 0.1 to 1.0 parts by weight of a retarder and 0.1 to 2.0 parts by weight of an alkali active agent are included.

The retarder may be added for the purpose of securing workability for a certain period of time by adjusting the hydration rate of the mortar. The retarder includes boric acid and borates such as borax, sodium borate, potassium borate, gluconic acid, citric acid, tartaric acid, glucoheptonic acid, arabonic acid, malic acid or citric acid and their sodium, potassium, calcium, magnesium, ammonium, triethanolamine oxycarboxylic acids such as inorganic salts or organic salts such as these; Monosaccharides such as glucose, fructose, galactose, saccharose, xylose, abitose, lipose, and isomerized sugar, oligosaccharides such as disaccharide and trisaccharide, oligosaccharide such as dextrin, or polysaccharide such as dextran; sugars such as molasses containing these; sugar alcohols such as sorbitol; magnesium silicofluoride; phosphoric acid and its salts or boric acid esters; aminocarboxylic acids and their salts; 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 an earth metal salt, and its derivative(s), etc. can be used.

The alkali activator is a component affecting strength expression, and one or a mixture of two or more selected from alkali metal hydroxides, chlorides, sulfur oxides and carbonates may be used, and preferably any one of KOH, NaOH and CaOH ₂ It is advantageous in terms of strength development to use the above.

On the other hand, according to another embodiment of the present invention, a first step of removing the deteriorated portion of the concrete structure and removing foreign substances and then cleaning the surface of the deteriorated portion by dry using a high-pressure air compressor; A second step of applying an alkali recovery agent to the surface-cleaned concrete structure and applying a rust preventive coating agent to the exposed reinforcing bars; a third step of applying the crack-reducing flame-resistant polymer mortar composition having excellent thixotropy to the surface to which the alkali recovery agent is applied and the anti-rust coating agent is applied; and a fourth step of applying a surface protection agent after the mortar composition for repair and reinforcement is applied.

First, by chipping the deteriorated part of the damaged concrete structure, the surface or cross-section is trimmed until an undamaged part emerges. In other words, cracks, droppings, rusting, lifting, and corrosion of reinforced concrete structures caused by aging phenomena such as alkali aggregate reaction, freeze damage, salt damage, or neutralization (carbonation) are removed by chipping and dry using a high-pressure air compressor. Clean the deteriorated part with In this case, an electric hammer or a hand tool may be used.

Then, an alkali recovery agent is applied to the surface-cleaned concrete structure, and an anti-rust coating agent is applied to the exposed reinforcing bar.

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

In addition, the rust-preventive coating agent may use a ginseng salt-based rust-preventing agent, but is not limited thereto.

Then, the alkali recovery agent is applied and the anti-rust coating agent is applied to the surface to which the crack reducing type flame-resistant polymer mortar composition excellent in thixotropy is applied by spraying or hand plastering.

The crack-reducing flame-resistant polymer mortar composition excellent in thixotropy used in the present invention contains 100 parts by weight of a binder, 80 to 200 parts by weight of silica sand, 0.1 to 5.0 parts by weight of a moisturizing material, 10 to 50 parts by weight of a polymer, 0.5 to 2.0 parts by weight of a shrinkage inhibitor. Parts by weight, filler 2-40 parts by weight, antifoaming agent 0.1-1.0 parts by weight, expanding agent 5-20 parts by weight, curing accelerator 0.1-10 parts by weight, fluidizing agent 0.2-20 parts by weight, thickener 2-20 parts by weight, retarder 0.1 -1.0 parts by weight and 0.1 to 2.0 parts by weight of an alkali active agent.

The binder includes 20 to 50% by weight of crude portland cement and 50 to 80% by weight of alumina cement, and the alumina cement is selected from calcium aluminate (CA) and C ₁₂ A ₇ which is amorphous calcium aluminate. at least one, and the moisturizing material contains sodium hyaluronate and sacran in a 1:1 weight ratio, and the thickener consists of a mixture of a cellulose-based organic thickener and sepiolite, which is a porous inorganic thickener, and the polymer is made of at least one of EVA (Ethylene-vinyl acetate) resin, acrylic re-emulsifying resin, and SBR (Styrene Butadiene Rubber), the anti-shrinkage agent is made of neopentyl glycol, and the filler is silica fume, blast furnace slag and fly. Consists of any one or more of ash, and the expanding agent is any one or more of calcium sulfoaluminate (CSA), anhydride, phosphate gypsum, and hydrofluoric acid gypsum, and the curing accelerator is sodium silicate, lithium carbonate and lithium sulfate. It consists of at least one selected from among, the fluidizing agent is any one or more of polycarboxylic acid and naphthalene, the retarder is any one or more of citric acid, tartaric acid, and gluconic acid, and the alkali active agent is KOH, NaOH and It is characterized in that at least one of CaOH ₂ .

In the present invention, when applying the crack-reducing flame-resistant polymer mortar composition with excellent thixotropy, use a spray or trowel to first pour 5 to 15 mm, second and third pour 20 to 50 mm, and final pour 5 to 15 It is desirable to construct and plaster with a thickness of mm.

In the present invention, the method may further include applying a primer (base agent) to the trimmed target surface before applying the crack-reducing flame-resistant polymer mortar composition having excellent thixotropy. In the present invention, as the primer, a commonly used primer can be used, and by using the primer, the adhesion to the concrete surface to be constructed can be further strengthened and the construction can be performed more efficiently.

Next, the crack-reducing flame-resistant polymer mortar composition with excellent thixotropy is applied to the crushed concrete site to smooth finish and dry, and then a thin coating of a special surface protection agent according to the present invention is applied to the surface to protect the repaired surface from external conditions. .

The surface protection agent is applied using a brush, roller, spray, etc. to neutralize the concrete structure and prevent salt damage. After mixing the synthetic resin fiber having a density of 10 to 1000 g/m3 in the coating solution, 30 to 300 parts by weight of the inorganic powder component are mixed with 100 parts by weight of the mixture obtained by mixing the acrylic resin, rubber chip, airgel and powder component. Use a surface protectant.

More specifically, the coating solution containing the MMA resin is composed of 78 to 86 wt% of the MMA resin, 0.5 to 5 wt% of a peroxide-based curing agent, and 10 to 20 wt% of the additive. As the MMA resin, 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 may be used. At this time, the mixing ratio is preferably low-viscosity MMA: high-viscosity MMA = 40 to 70: 30 to 60 weight ratio.

In addition, in the MMA or mixed MMA resin, one or more mixtures selected from SIS (styrene isoprene styrene), SBR (styrene butadiene rubber), and SBS (styrene butadiene styrene) are mixed within the range of 1 to 10% by weight of modified MMA. can also be used

In the present invention, the peroxide-based curing agent serves to initiate the polymerization reaction of the MMA resin, and the curing agent includes benzoyl peroxide, t-butylperoxybenzoide, methylethylketone peroxide, cumene hydroperoxide or 2, 5-dimethylhexyl-2,5-diperoxybenzoate and the like can be used. 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 initiation reaction is lowered, and consequently, there is a problem in that the strength characteristics of the flooring material are lowered, When it exceeds 5.0 wt%, there is a problem in that it is difficult to efficiently control the polymerization reaction.

In the present invention, the additive may include an inorganic silane resin, a dispersant, an antifoaming agent, an emulsifier, and the like. In addition, when the base material is concrete, cement may be additionally included in the additive to strengthen adhesion to concrete.

The inorganic silane resin is a transparent liquid material made of aqueous colloidal nanosilica, exhibits strong alkalinity of pH 12 or higher, and penetrates into the interior of the substrate such as concrete through excellent osmotic action to hydrate the substrate, thereby strengthening and protecting the substrate and the interior. do

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

A synthetic resin fiber is mixed with the coating liquid obtained above. The synthetic resin fiber may be a mixture of synthetic resin fibers having a density of 10 to 1000 g/m ³ , for example, nylon-based or polyester-based synthetic resin fibers may be used. These synthetic resin fibers serve to enhance bonding strength.

Then, the acrylic resin, rubber chips, airgel, cellulose powder and powder components are further mixed. Specifically, 20 to 30 parts by weight of acrylic resin, 10 to 15 parts by weight of rubber chips, 1 to 10 parts by weight of cellulose powder, 0.5 to 5 parts by weight of airgel, and 10 to 40 parts by weight of powder components may be mixed.

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

In addition, as the rubber chip, recycled rubber chips such as natural rubber chips or waste tires may be used, and specifically, those pulverized to about 0.2 to 0.8 mm in particle diameter may be used. The rubber chip is mixed with the acrylic resin to provide insulation and anti-condensation effects to the coating layer, prevent damage and floatation of the coating layer, and absorb external shocks.

The airgel (aerogel) can specifically use silica airgel powder, a transparent nano-porous material having a particle diameter of about 10-2000 μm, and a density of about 0.05-0.1 g/cm ³ , a porosity of 90-99%, a specific surface area It is preferable to use 200 to 2000 m ² /g, and a pore volume of 2 to 10 cm ³ /g. The airgel serves to reduce the influence of the external environment by giving an insulating effect due to the pores existing inside the particles.

It is preferable to use the cellulose powder having an average diameter of 1 to 100 μm, and it serves to adjust the viscosity of the surface protection agent coating solution and to enhance the adhesion strength to the surface.

In the present invention, it is preferable to use a mixture of 30 to 50 wt% of mica having a particle size of 1 to 100 μm, 30 to 50 wt% of stone powder, and 5 to 20 wt% of titanium oxide as the powder component in the present invention.

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

The stone powder serves to strengthen abrasion resistance, slip resistance, adhesive strength, and the like.

The titanium oxide serves to improve the thermal insulation performance by suppressing the transmission of radiant light, and to block ultraviolet rays and to impart antifouling properties.

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

Specifically, it is preferable to use the inorganic powder component comprising silica powder, alumina cement and bentonite powder.

More specifically, the inorganic powder component is preferably composed of 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 accelerate 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 diameter of about 0.05 to 2.0 mm.

The bentonite powder absorbs water or moisture and serves to adjust the viscosity, and it is preferable to use one having a particle diameter of about 0.05 to 1.0 mm.

The surface protection agent thus obtained is applied to the surface coated with the mortar composition for repair and reinforcement, and the final operation is finished by coating. Due to the above operation, the bonding force is increased, the peeling phenomenon is prevented, and the waterproof effect is increased. In addition, water resistance is exhibited and water absorption is low, so an excellent waterproof effect is exhibited, and cracking of concrete due to freezing and thawing is suppressed.

The surface protection agent according to the present invention is excellent in effects such as weather resistance, surface strength and water resistance reinforcement only by one coat, but it is preferable to repaint it two to three times in order to optimally exhibit its functions. In the present invention, the surface protection agent is preferably applied to the surface on which the mortar composition for repair and reinforcement has been cured in an amount of 20 to 200 g/m ² , and the coating thickness is preferably applied to a thickness of 50 to 300 μm in the pre-drying stage.

Hereinafter, the present invention will be described in more detail through Examples and Experimental Examples. However, these examples are only for helping the understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

[Example]

(Example 1)

A binder was prepared by mixing 10.0 wt% of crude Portland cement and 25.0 wt% of alumina cement.

As a moisturizing material, 1.0 wt% of a moisturizing material mixture containing sacran and sodium hyaluronate in a 1:1 weight ratio, 0.75 wt% of a cellulose-based organic thickener, and 0.25 wt% of sepiolite, a porous inorganic thickener 1.0% by weight of EVA resin as polymer resin, 6.0% by weight of neopentylglycol anti-shrink agent, 13.0% by weight of silica fume, 2.5% by weight of calcium sulfoaluminate (CSA) as expanding agent and 2.5% by weight of anhydrite, curing accelerator 2.0 A mortar composition was prepared by uniformly mixing an appropriate amount of water with an appropriate amount of water, 0.5 wt% of a fluidizer, 0.25 wt% of an antifoaming agent, 0.25 wt% of a retarder, 0.25 wt% of an alkali active agent, and 35.0 wt% of silica sand.

(Example 2)

It was prepared in the same manner as in Example 1, except that 1.0 wt% of a thickener mixture containing a cellulose-based organic thickener and a porous inorganic thickener, sepiolite, in a 1:1 weight ratio was used.

(Example 3)

Prepared in the same manner as in Example 2, but 13.0 wt% of crude portland cement and 10.0 wt% of each of calcium aluminate (CA) and amorphous calcium aluminate C ₁₂ A ₇ as alumina cement in a 1:1 content ratio, respectively It differs only in that the mortar composition was prepared by mixing the

(Example 4)

It was prepared in the same manner as in Example 1, except that 5.95 wt% of EVA resin was mixed as a polymer resin, and 0.05 wt% of sodium chloride was further mixed as a thixotropic enhancer to prepare a mortar composition.

(Comparative Example 1)

It was prepared in the same manner as in Example 1, except that it contained 7.8 wt% of EVA resin as a polymer resin, did not use a moisturizing material, did not use inorganic sepiolite as a thickener, and used only 0.20 wt% of a cellulose-based thickener as an organic thickener. .

Specific mixing conditions of Comparative Example 1 and Examples 1 to 4 are shown in Table 1 below.

Blending conditions (wt%) Comparative Example 1 Example 1 Example 2 Example 3 Example 4




binder


cement crude steel portland cement 10.0 10.0 13.0 13.0 13.0 Alumina Cement (CA) 25.0 25.0 20.0 10.0 10.0 Amorphous Alumina Cement (C12A7) 0.0 0.0 0.0 10.0 10.0
swelling agent Calcium sulfoaluminate (CSA) 2.5 2.5 3.5 3.5 3.5 anhydrite 2.5 2.5 3.5 3.5 3.5 Subtotal 1 40.0 40.0 40.0 40.0 40.0 filler Silica fume 13.0 13.0 13.0 13.0 13.0 Subtotal 2 13.0 13.0 13.0 13.0 13.0 silica sand 35.0 35.0 35.0 35.0 35.0







admixture polymer EVA 7.8 6.0 6.0 6.0 5.95
thickener cellulose 0.20 0.75 0.50 0.50 0.50 Sepiolite 0.00 0.25 0.50 0.50 0.50
Moisturizer Sakran 0.00 0.50 0.50 0.50 0.50 Sodium Hyaluronate 0.00 0.50 0.50 0.50 0.50 sodium chloride 0.00 0.00 0.00 0.00 0.05 anti-shrink agent neopentyl glycol 0.50 0.50 0.50 0.50 0.50 hardening accelerator lithium carbonate 2.00 2.00 2.00 2.00 2.00 glidant polycarboxylic acid 0.50 0.50 0.50 0.50 0.50 antifoam 0.25 0.25 0.25 0.25 0.25 retardant 0.25 0.25 0.25 0.25 0.25 alkali activator 0.50 0.50 0.50 0.50 0.50 Subtotal 3 12.0 12.0 12.0 12.0 12.0 Sum 100.0 100.0 100.0 100.0 100.0

performance evaluation

(1) Comparison of comprehensive mechanical properties

Test specimens were prepared using the mortar compositions prepared in Examples and Comparative Examples to compare overall mechanical properties, and the results are shown in Table 2 below.

Item Comparative Example 1 Example 1 Example 2 Example 3 Example 4 flow (0 min) 180 180 180 180 180 28 days
Compressive strength (N/mm ² ) 54.0 53.5 52.0 50.0 55.0 28 days
Flexural strength (N/mm ² ) 10.5 12.5 14.2 13.5 14.5 28 days
Adhesive strength (N/mm ² ) 1.2 1.8 2.0 1.8 2.05 28 days
Length change rate (%) 0.08 0.05 0.02 0.01 0.01

Referring to Table 2, it can be seen that the mortar composition prepared according to the example of the present invention has the same or more excellent effect in overall mechanical properties compared to the comparative example.

That is, in the case of 28-day flexural strength and 28-day adhesive strength, it can be seen that the Example of the present invention has a more excellent effect than the Comparative Example.

(2) Comparison of weight reduction rate

Test specimens were prepared using the mortar compositions prepared in Examples and Comparative Examples to compare weight reduction rates, and the results are shown in Table 3 below.

As for the specific test method, the test specimen was prepared according to the test method of KS F 2476 polymer mortar, cured after curing for 28 days, and then immersed in a 5% H ₂ SO ₄ solution to measure the weight loss by age to compare acid resistance.

Item
Comparative Example 1 Example 1 Example 2 Example 3 Example 4 weight loss rate
(%) 14 day immersion product 5.82 5.25 5.05 4.89 4.52 28 day immersion product 6.82 6.52 6.25 4.02 4.00

Referring to Table 3, in the case of the crack reducing type flame-resistant polymer mortar composition having excellent thixotropy according to the present invention, it can be seen that the acid resistance is superior to that of the comparative example.

(3) Comparison of water retention and flow

In order to compare the water retention according to the mixing rate of the moisturizing material, it was measured using the 9.12.1.1 water retention device of KS5219 [Masonry Cement]. Water retention was measured by applying the water ratio of the same sample. In addition, in order to measure the change over time according to water retention, the flow was measured according to the test method of KS F 2476 Polymer Cement Mortar Test Method 6.1.2 after mixing to measure the change. The results are shown in Table 4 below.

Item
Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Conservatism (%)
72 75 82 92 93.0
flow
(mm) Immediately 180 180 180 180 180 30 minutes 150 180 180 180 180 60 minutes 145 150 160 160 180 90 minutes 130 145 170 170 175

Referring to Table 4, it can be seen that, in the case of the crack-reducing flame-resistant polymer mortar having excellent thixotropy produced according to the embodiment of the present invention, the water-retaining property and the flow characteristic are excellent compared to the comparative example.

In particular, in one embodiment of the present invention, 1.0% by weight of a moisturizing material mixture containing sacran and sodium hyaluronate in a 1:1 weight ratio as a moisturizing material and a cellulose-based organic thickener and sepiolite as a porous inorganic thickener In the case of Examples 2 and 3 using 1.0 wt % of the thickener mixture contained in a 1:1 weight ratio, it can be seen that the water retention properties are more excellent, and the flow characteristics are also superior to those of Examples 1 and Comparative Examples.

In addition, 1.0% by weight of a moisturizing material mixture containing sacran and sodium hyaluronate in a 1:1 weight ratio as a moisturizing material, 0.05% by weight of sodium chloride as a thixotropic enhancer, and a cellulose-based organic thickener and a porous inorganic thickener In the case of Example 4 using 1.0 wt% of a thickener mixture containing sepiolite in a 1:1 weight ratio, it can be seen that water retention is more excellent and flow characteristics are also superior to those of Comparative Examples and Examples 1 to 3.

(4) Comparison of sag resistance

In order to compare the sag resistance according to the mixing rate of the thickener, the position correction of 7.3 of KS L 1592 was also tested according to the test method. The specific test method is to use a 150X150mm ceramic tile, knead the mortar, and then pour it on the gypsum board with a 6X6mm uneven trowel and attach it. After the work is carried out at 20±5℃ and 45~55% relative humidity, spread it on the gypsum board and press the tile pieces so that the mortar is 3mm thick. After placing the specimen horizontally in a thermo-hygrostat, after 20 minutes, twist the attached tile by 90° and return it to its original state. The sag properties were compared. The results are shown in Table 5 below.

Item Comparative Example 1 Example 1 Example 2 Example 3 Example 4 the flowing way
(mm) 3.2 2.5 2.2 0.0 0.0

Referring to Table 5, it can be seen that the crack-reducing flame-resistant polymer mortar with excellent thixotropy produced according to the embodiment of the present invention has superior sag resistance compared to the comparative example.

In particular, in one embodiment of the present invention, Examples 2 to 3 using 1.0% by weight of a thickener mixture containing a cellulosic organic thickener and sepiolite, a porous inorganic thickener, in a 1:1 weight ratio, and 0.05% by weight of sodium chloride as a thixotropic enhancer It can be seen that in the case of Example 4 further including a sag resistance is superior to that of Example 1 and Comparative Example.

(5) Comparison of thixotropy (viscosity)

In order to compare the thixotropy according to the incorporation of the thixotropic enhancer, the viscosity of each sample was measured with a rotary viscometer. As for the specific measurement method, the values were recorded by continuously operating the viscometer for 0 minutes, 30 minutes, and 60 minutes based on the time of rubbing with water. The values shown in [Table 6] below are results obtained by combining data obtained with a rotary viscometer (Brookfield, LV Viscometer Spindle No.64 10 rpm at 25°C).

Item hour Comparative Example 1 Example 1 Example 2 Example 3 Example 4
viscosity
(Unit: cps) 0 minutes 30,000 30,000 30,000 30,000 30,000 15 minutes 43,000 36,000 35,000 35,000 30,000 30 minutes 46,000 42,000 39,000 38,000 32,000 45 minutes not measurable 45,000 42,000 40,000 35,000 60 minutes not measurable Measurable 45,000 45,000 42,000

Referring to Table 6, it can be seen that in the case of the crack-reducing flame-resistant polymer mortar with excellent thixotropy produced according to the embodiment of the present invention, the viscosity characteristic is superior to that of the comparative example.

In particular, it can be seen that in the case of Example 4, which further contains 0.05% by weight of sodium chloride as a thixotropic enhancer in one embodiment of the present invention, the viscosity (thixotropic) properties are superior to those of Comparative Examples and Examples 1 to 3.

1 is a photograph of the result of testing the crack resistance according to an embodiment and a comparative example of the present invention.

Crack resistance tests according to Examples and Comparative Examples of the present invention were conducted as follows.

In order to compare the crack resistance according to the mixing rate of the thickener and moisturizer, the number of cracks after the experiment was compared by the plastic shrinkage test method of Krail. The specific test method is to manufacture a 900X600X10 mm mold, fill the mold with mixed mortar, and apply plastering in the same direction to prepare a specimen. After maintaining for 24 hours in a constant temperature and humidity room of 4.5-5 m/s, the amount of cracking was measured.

As a result, as shown in FIG. 1 , it can be seen that no cracks occur in Example 3 of the present invention. It is considered that this is because the generation of tensile stress due to the improvement of moisture retention and sagging resistance is reduced.

As shown in Tables 2 to 5 and FIG. 1, in the case of the crack-reducing flame-resistant polymer mortar composition having excellent thixotropy according to the present invention, the physical properties are remarkably superior to that of the conventional flame-resistant polymer mortar composition, and in particular, flexural strength and adhesion. It can be seen that the strength is remarkably excellent, and it exhibits excellent effects in moisture retention and sag resistance, so that the crack resistance is also excellent.

In addition, from the above results, using the crack-reducing flame-resistant polymer mortar composition with excellent thixotropy according to the present invention to use the repair and reinforcement method for concrete structures, the performance of the mortar is excellent, so workability is remarkably improved, and adhesion to concrete It has excellent properties and excellent properties such as sag resistance and crack resistance, so it can be confirmed that the repair and reinforcement of concrete structures can be efficiently performed, and the effect of repair and reinforcement can be maintained for a long period of time.

The present invention described above is not limited to the above-described embodiments because various substitutions and changes can be made to those of ordinary skill in the art to which the present invention pertains without departing from the technical spirit of the present invention. .

Claims (4)

Binder 100 parts by weight, silica sand 80-200 parts by weight, moisturizing material 0.1-5.0 parts by weight, polymer 10-50 parts by weight, anti-shrinkage agent 0.5-2.0 parts by weight, filler 2-40 parts by weight, anti-foaming agent 0.1-1.0 parts by weight, swelling agent 5 to 20 parts by weight, 0.1 to 10 parts by weight of a curing accelerator, 0.2 to 20 parts by weight of a glidant, 2 to 20 parts by weight of a thickener, 0.1 to 1.0 parts by weight of a retardant, and 0.1 to 2.0 parts by weight of an alkali active agent. As this excellent crack reduction type flame-resistant polymer mortar composition,
The binder comprises 20 to 50% by weight of crude portland cement and 50 to 80% by weight of alumina cement,
The alumina cement is at least one selected from calcium aluminate (CA) and C ₁₂ A ₇ which is an amorphous calcium aluminate, and the moisturizing material is sodium hyaluronate (Sodium hyaluronate) and sacran (Sacran) 1:1 Including in a weight ratio, the thickener consists of a mixture of a cellulose-based organic thickener and a porous inorganic thickener, sepiolite,
The polymer is made of any one or more of EVA (Ethylene-vinyl acetate) resin, acrylic re-emulsifying resin, and SBR (Styrene Butadiene Rubber), the anti-shrinkage agent is made of neopentyl glycol, and the filler is silica fume, blast furnace slag. and fly ash, wherein the expanding agent is any one or more of calcium sulfoaluminate (CSA), anhydrite, phosphate gypsum, and hydrofluoric acid gypsum, and the curing accelerator is sodium silicate, lithium carbonate and Consists of at least one selected from lithium sulfate, the fluidizing agent is at least one of polycarboxylic acid and naphthalene, the retarder is any one or more of citric acid, tartaric acid, and gluconic acid, and the alkali activator is KOH, A crack-reducing flame-resistant polymer mortar composition having excellent thixotropy, characterized in that at least one of NaOH and CaOH ₂ .
According to claim 1,
The moisturizing material further includes sodium chloride, and the sodium chloride is a crack-reducing flame-resistant polymer mortar composition having excellent thixotropic properties, characterized in that it contains 1.0 to 5.0 parts by weight based on 100 parts by weight of the moisturizing material.
According to claim 1,
The thickener is a crack-reducing flame-resistant polymer mortar composition with excellent thixotropy, characterized in that the cellulose-based organic thickener and the porous inorganic thickener, sepiolite, are included in a weight ratio of 1:1.
A first step of removing the deteriorated portion of the concrete structure, removing foreign substances, and then dry cleaning the surface of the deteriorated portion using a high-pressure air compressor;
A second step of applying an alkali recovery agent to the surface-cleaned concrete structure and applying a rust preventive coating agent to the exposed reinforcing bars;
A third step of applying the crack-reducing flame-resistant polymer mortar composition having excellent thixotropy of any one of claims 1 to 3 on the surface to which the alkali recovery agent is applied and the anti-rust coating agent is applied; and
A fourth step of applying a surface protection agent after the crack-reducing flame-resistant polymer mortar composition having excellent thixotropy is applied;

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