KR101674923B1 - Repairing method of concrete structure using high-strength polymer mortar and fireproof mortar - Google Patents

Abstract

The present invention relates to a high strength polymer mortar, and to a fireproof repair method of a concrete structure using fireproof mortar. More particularly, the present invention relates to a repair method to repair a thermally deteriorated region in a concrete structure by using a fireproof mortar composition which can be simply put on the surface or the cross-sectional area of the concrete structure by spray-coating. The polymer mortar has high strength and excellent fire resistance, and thus is suitable to be used for the repair method under inadequate environment. Also, the polymer mortar has excellent durability with little amount of rebounding, and has excellent physical properties such as compression strength, flexural strength, and the like. Thus, the fireproof repair method of a concrete structure using the polymer mortar can prevent problems regarding thermal spalling in case of fire after repairing the concrete structure.

Description

[TECHNICAL FIELD] The present invention relates to a high-strength polymer mortar and a fireproof mortar for a concrete structure using a high-strength polymer mortar and a refractory mortar,

The present invention relates to a refractory repairing method for a concrete structure using a high strength polymer mortar and a refractory mortar, and more particularly, to a fire proofing method and a refractory mortar capable of preventing the explosion due to water vapor in a repair mortar The present invention relates to a method of refracting and repairing a concrete structure capable of maintaining a maintenance effect for a long period of time.

Generally, concrete used in construction and civil engineering structures is exposed to high temperature in the event of fire, resulting in explosion of scattering of debris from the surface. In the case of high-strength concrete with a dense internal structure when the water inside the concrete evaporates due to high-temperature heating, it is known that the explosion phenomenon occurs because the water vapor pressure is extremely increased because there is no ventilation passage for discharging water vapor. It is more problematic because of the use of high-strength concrete in ultra-high-rise reinforced concrete structures such as large office buildings and kitchen complex buildings in recent years.

When such a heat radiation phenomenon occurs, the covered concrete is broken, and the high temperature is transmitted to the inside of the structure and the reinforcing steel, which causes a decrease in the strength of the fatal member, which causes a major accident such as a collapse of the structure.

For example, a method of covering the surface of a concrete member with a steel plate (steel plate covering method), an organic material (organic fiber) having a low melting point in a concrete bimbe, A method of attaching various fireproof panels to the surface of a concrete member with an anchor (a method of attaching a refractory panel), a method of applying various refractory coatings to the surface of a concrete member (a refractory paint application method Method) have been proposed.

However, there is a problem in that the steel sheet coating method is complicated and takes a high cost, and when the steel sheet is damaged by heat in the case of fire, it becomes useless. In the heat resistant concrete method, fluidity is lowered due to incorporation of organic fibers, There is a problem that the refractory panel attachment method is complicated in construction process and the cost is high. In addition to the refractory panel, in addition to the refractory panel, there is a problem that the cross section of the member increases, and the refractory paint application method is simple in construction The possibility of increasing the member cross section is small, but the problem that the fire resistance performance of the required level is not satisfied is pointed out.

In recent years, a fireproof mortar spraying method in which a porous fireproof mortar is sprayed on the surface of a structure to form a fireproof layer has been developed and widely used. This method has excellent heat shielding performance, Compared to existing methods, molds are not needed and they can be used in places where the shape is not uniform, which is excellent in workability. However, since it is porous, its strength is insufficient and external deterioration factors such as air and water are easily penetrated. have.

Several techniques have been proposed to solve the problems of the conventional fireproof mortar spraying method.

Among them, Korean Patent Registration No. 10-0582840 discloses a method for improving the durability performance of buildings and civil structures by producing a high-toughness and high-refractory mortar composition by mixing polymer cement mortar, short fiber, refractory powder, High fire resistance mixed mortar composition capable of simultaneously improving refractory performance such as heat resistance and resistance to explosion due to heat.

In addition, Korean Patent No. 10-0659458 discloses a method of mixing a polypropylene powder, a glass bead, a resin bead, and the like with a dry mortar composed of an admixture composed of cement, a blast furnace slag fine powder, a limestone fine powder, etc. and fine aggregate, swelling agent, The present invention proposes a technology for injecting and curing a refractory filled mortar prepared by mixing a heat absorbing material, an organic fiber, a water reducing agent and a mixing water into a space formed between a surface of a concrete member and a finishing panel to exert a fire resistance performance by self-

Korean Patent No. 10-1117634 discloses a cement admixture comprising a binder including cement, slag, and a swelling agent, an inorganic salt additive including a silica fine powder, a silicide salt, a potassium sulfate, an EVA resin, an auxiliary including a PP resin, , A thickener and the like, and an aggregate. The present invention provides a refractory mortar composition which can exhibit stable fire resistance by adding the inorganic salt additive, has excellent compression strength and durability, and has improved resistance to high temperature do.

In addition, Korean Patent No. 10-1016156 discloses a fire-resistant mortar composed of a binder, a fiber, a melamine-based fluidizing agent, and an aggregate on the surface of a concrete structure, which increases the amount of fiber added to provide excellent strength and improve fire resistance and heat insulation This paper proposes a fireproofing technique for concrete structures.

As described above, most of the conventional techniques claim that the refractory concrete composition has the effect of improving the durability by adjusting the ratio of the composition of some refractory concrete or improving the endothermic and thermal insulation performance by adding a material having an endothermic performance. The degree of improvement is not large.

On the other hand, in general reinforced concrete structures, concrete detachment due to neutralization, salt erosion, chemical erosion, freezing and thawing, poor construction, and corrosion of reinforcing steel occur over time after construction, . Therefore, it is necessary to repair the deteriorated part by using repair mortar or the like because the deterioration of the concrete structure continues to cause the collapse of the structure.

In the case of existing repair mortar, it is often used to form a compact structure in order to exhibit high strength performance, and a composition for minimizing drying shrinkage cracks generated in the curing process is mainly used.

However, in the case of such a high-strength repair mortar, the above-mentioned concrete explosion phenomenon occurs more frequently than general mortar, and in particular, when the partial repair is performed, Occurs.

Therefore, in the case of the repair mortar, studies on the composition capable of preventing the explosion of the concrete are underway in various fields, but the conventional techniques have problems in each case, and therefore there is a great need for improvement.

The present invention has been developed in order to overcome the problems and limitations of the prior art as described above and it is an object of the present invention to repair a deteriorated portion of a concrete structure by using a refractory mortar composition which can be simply applied to a surface or a cross section of a concrete structure by spraying As a construction method, it has high fire resistance and excellent fire resistance. It is suitable for maintenance work in poor environments, has excellent durability, has a small amount of rebound, and has excellent properties such as compressive strength and bending strength. And to provide a refractory repair work method for a concrete structure which can prevent a fire.

In order to achieve the above object,

(a) a first step of chipping, grinding, and cleaning the concrete structure requiring repairing, followed by high pressure cleaning;

(b) a second step of applying the rust preventive agent to the exposed reinforcing bars after the concrete is dropped in the first step;

(c) a third step of applying an adhesive to the surface of the concrete structure and the reinforcing bar after the second step;

(d) 1 to 5 parts by weight of a CSA quick-setting swelling agent, 2 to 10 parts by weight of blast furnace slag powder and 1 to 5 parts by weight of fly ash are mixed with 20 to 40 parts by weight of the binder on the surface of the surface to which the adhesive is applied 0.01 to 1.0 part by weight of porous organic peroxide, 0.05 to 2.0 parts by weight of porous perlite, 0.1 to 1.0 part by weight of silica sand, 0.2 to 2.0 parts by weight of glass fiber, 0.1 to 0.5 parts by weight of neopentyl glycol, A third component obtained by mixing 0.01 to 2.0 parts by weight of a fine alumina powder, 0.01 to 2.0 parts by weight of a fine silica powder and 0.01 to 2.0 parts by weight of a polyvinyl alcohol powder, A fourth component composed of 0.1 to 5.0 parts by weight of a propylene fiber, 0.1 to 3.0 parts by weight of a water-swellable polysaccharide polymer powder and 0.01 to 1.0 part by weight of a PVC fiber, is sprayed to form a cross section, step; And

(d) a fifth step of applying a refractory coating agent on the surface of the refractory mortar composition sprayed and cured;

The present invention provides a refractory repairing method for a concrete structure including:

In one embodiment of the present invention, in the fourth step, the binder is one or a mixture of two or more selected from the group consisting of portland cement, white portland cement, alumina cement, .

In an embodiment of the present invention, in the fourth step, the binder comprises 100 parts by weight of artificial marble waste powder, 20 to 50 parts by weight of a slag-containing mixture, 20 to 50 parts by weight of phosphorus- 20 to 50% by weight of a cemented cement comprising 10 to 30 parts by weight of sintered magnesia cement and 5 to 20 parts by weight of ammonium phosphate; 30 to 60 wt% portland cement; 5 to 20% by weight of a cellulose fiber; And

And 5 to 10% by weight of an EVA resin.

In one embodiment of the present invention, the slag-containing mixture comprises 65 to 80% by weight of blast furnace slag having a specific surface area of 6,000 to 7,000 cm ² / g, 10 to 20% by weight of lime, 5 to 15% cm ² / g specific surface area to 20,000cm having a fineness of ² / g by the average particle diameter of 1 ~ 10㎛ the kiln mixed and pulverized mechanochemical activation process of the dust mixture consisting of 5 to 20% by weight in a vibration mill To 10,000 to 20,000 cm < ² > / g.

In one embodiment of the present invention, in the fourth step, the second component further comprises 1 to 5 parts by weight of a silicon powder component composed of n-octitriethoxysilane.

In one embodiment of the present invention, in the fifth step, the refractory coating agent comprises 10 to 50 wt% of an epoxy resin, 5 to 40 wt% of a polymethyl methacrylate resin, 1 to 25 wt% of a diluent, 0.1 Soluble oil 1 to 20 parts by weight based on 100 parts by weight of a main component obtained by mixing 1 to 20% by weight of an inorganic filler, 1 to 20% by weight of an inorganic filler, 0.1 to 5% by weight of an accelerator, 0.05 to 20% 5 to 50 parts by weight of a polyamide and 0.1 to 50 parts by weight of an amine compound based on 100 parts by weight of the obtained aqueous solution are mixed with each other in an amount of 0.1 to 10% by weight, an emulsifier of 1 to 10% by weight, an accelerator of 5 to 20% To 40 parts by weight of a curing agent component obtained by mixing 5 to 50 parts by weight of a curing agent component and 1 to 15 parts by weight of a powder component obtained by mixing white cement and limestone powder at a ratio of 10 to 90:90 to 10 parts by weight, The application of the mortar composition before curing .

In one embodiment of the present invention, the method further comprises a step of applying a component obtained by mixing the acrylic resin with the bar-cut fiber powder on the surface of the third surface coated with the adhesive.

The characteristics and advantages of the refractory repairing method of the concrete structure using the high strength polymer mortar and the refractory mortar according to the present invention are as follows.

1. First, by using blast furnace slag powder and fly ash for the first component used in the mortar composition, active silicon dioxide (SiO ₂ ), which is a reactive active ingredient of the material, It shows strong characteristics against chemical corrosion. By acting CSA type hard swelling agent, it increases activity of blast furnace slag and fly ash, induces early hardening and prevents cracks, and it is possible to secure high strength performance.

2. The second component used in the mortar composition also contains an acrylic-based organic lightweight agent and porous pearlite, silica, glass fiber, neopentyl glycol, loess and silica fume components to increase the thickness of the spray and prevent sagging, It is possible to improve the durability by lowering the water repellency and at the same time, the water repellency can be enhanced, so that it has a long-term durability and water resistance.

3. Further, since the third component used in the mortar composition includes the alumina fine powder and the fine silica powder, the firing of the mortar is promoted, so that the firing strength is increased and the bulkability is improved, and the adhesive force of the mortar is increased by including the polyvinyl alcohol powder The friction between the components is reduced and the dispersibility is improved, so that the effect of dispersing heat in the fire is excellent.

4. Further, by including the polypropylene fiber, the water-swellable polysaccharide-based polymer and the PVC fiber in the fourth component used in the mortar composition, the bonding strength with concrete is increased and the penetration of external harmful substances is blocked, And it is utilized as a discharge passage for vapor pressure in case of fire, so that the fire resistance can be increased.

5. It is also possible to improve the barrier performance against heat by applying a refractory coating agent containing epoxy and a refractory additive to the surface of the mortar, thereby further improving the refractory performance of the repair mortar.

6. Further, in the application of the mortar, the adhesion performance of the mortar can be further improved by further using an acrylic liquid component including the special fibers made of the Vasartite fiber.

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

As described above, the refractory repair work method for a concrete structure according to the present invention comprises the following steps. In other words,

(a) a first step of chipping, grinding, and cleaning the concrete structure requiring repairing, followed by high pressure cleaning;

(b) a second step of applying the rust preventive agent to the exposed reinforcing bars after the concrete is dropped in the first step;

(c) a third step of applying an adhesive to the surface of the concrete structure and the reinforcing bar after the second step;

(d) 1 to 5 parts by weight of a CSA quick-setting swelling agent, 2 to 10 parts by weight of blast furnace slag powder and 1 to 5 parts by weight of fly ash are mixed with 20 to 40 parts by weight of the binder on the surface of the surface to which the adhesive is applied 0.01 to 1.0 part by weight of porous organic peroxide, 0.05 to 2.0 parts by weight of porous perlite, 0.1 to 1.0 part by weight of silica sand, 0.2 to 2.0 parts by weight of glass fiber, 0.1 to 0.5 parts by weight of neopentyl glycol, A third component obtained by mixing 0.01 to 2.0 parts by weight of a fine alumina powder, 0.01 to 2.0 parts by weight of a fine silica powder and 0.01 to 2.0 parts by weight of a polyvinyl alcohol powder, A fourth component composed of 0.1 to 5.0 parts by weight of a propylene fiber, 0.1 to 3.0 parts by weight of a water-swellable polysaccharide polymer powder and 0.01 to 1.0 part by weight of a PVC fiber, is sprayed to form a cross section, step; And

(d) a fifth step of applying a refractory coating agent on the surface of the refractory mortar composition sprayed and cured;

.

Hereinafter, each of the above steps will be described in detail.

First, when cracks are generated in concrete due to deterioration in concrete structures, the compressive strength of concrete and the tensile strength of reinforcing bars gradually decrease after a lapse of time, and the concrete exposed to the cracks is neutralized and corrosion of reinforcing bars occurs. Diagnosis and inspection of the structure should be carried out. If such a phenomenon occurs, the concrete structure must be repaired to maintain the life of the building for a long time.

The first step is a pretreatment step. In the pretreatment step, the concrete in which the cracks are generated and the exposed reinforcing bars are removed from the concrete structures requiring maintenance as a result of the inspection, and the sections are crushed by using a machine until the unreacted concrete comes out It is a process of refining. In this case, the outermost surface of the refined concrete is preferably provided with a rough surface so as to facilitate the attachment of the mortar.

Specifically, the surface condition of the concrete structure to be subjected to the repair work before the repair work of the concrete structure is checked, and the depth of the neutralization is measured using the phenolphthalein solution while chipping the surface of the deteriorated concrete. Remove the advanced concrete surface.

Subsequently, the concrete is removed and the surface is ground and cleaned using high-pressure water. A process of washing with an air compressor before the high-pressure water operation can be additionally provided.

After the pretreatment, concrete is removed in the pretreatment step, and the rust inhibitor is applied to the exposed reinforcing bars. That is, if the condition of the reinforcing bars is confirmed, if the corrosion of the reinforcing bars is severe, the back side of the reinforcing bars is taken out to remove the corrosion parts (rust) by using an iron brush or a grinder to the parts with high corrosion, It is possible to add a work of cutting a reinforcing bar and reinforcing it by inserting a reinforcing material such as a new reinforcing bar, a carbon rod, and a rod. In the present invention, an amine-based rust inhibitor such as a carboxylamine is preferably used as the rust inhibitor, but not limited thereto, and general rust inhibitor that can be used as a rust inhibitor of a steel can be used without limitation.

After the rust-preventive step, an adhesive is applied to the surface of the pretreated concrete structure and the rust-inhibited reinforcing bar. The adhesive is used to increase the adhesive force between the concrete matrix and the polymer mortar composition to be newly filled, and a commonly used adhesive may be used, which is not particularly limited in the present invention.

Specifically, the application of the adhesive is performed by applying an adhesive composed of an emulsion such as acrylic or silicone to a surface or a repair part of the structure by using a roller, a brush or the like. Since the adhesive has a high adhesive force by crosslinking with the concrete surface, It improves the adhesion when refractory mortar is applied to the process, thereby maintaining the durability performance continuously.

Next, the refractory mortar composition according to the present invention is sprayed onto the surface of the concrete structure and the reinforcing bars to which the adhesive is applied by using a mechanical injection device.

As the mechanical injection device that can be used in the present invention, it is preferable to use an integrated mortar injection device in which a mixing device, a discharge device, a generator, and a compressor are combined or mounted.

Hereinafter, each component constituting the refractory mortar composition according to the present invention will be described in detail.

The refractory mortar composition according to the present invention is prepared by preparing each of a first component, a second component, a third component and a fourth component, and mixing the components thus prepared.

Hereinafter, the above respective procedures will be described in detail.

First, a first component is prepared by mixing 1 to 5 parts by weight of CSA (calcium sulfur alumite) fast-growing swelling agent, 2 to 10 parts by weight of blast furnace slag powder and 1 to 5 parts by weight of fly ash .

In the present invention, the CSA type hard swelling agent is used for accelerating the hardening of the mortar, and the initial strength is applied to prevent the composition from sagging. The CSA quick-setting swelling agent used in the present invention is preferably contained in an amount of 1 to 5 parts by weight, more preferably 1 to 3 parts by weight, in order to ensure initial strength and exhibit fast curing and adhesion performance.

In the present invention, the blast furnace slag powder and the fly ash form the thickness of the mortar and serve to enhance the long-term strength by potential hydraulic reaction. The blast furnace slag powder and the fly ash used in the present invention preferably have an average particle diameter of not less than about 6,000 cm ² / g and an average particle diameter of not more than 5 μm. In the present invention, the blast furnace slag powder is preferably contained in a range of 2 to 10 parts by weight, and the fly ash is preferably contained in a range of 1 to 5 parts by weight.

Next, a second component is prepared, wherein the second component is selected from the group consisting of 0.01 to 1.0 parts by weight of an acrylic organic lightweight material, 0.05 to 2.0 parts by weight of porous perlite, 0.1 to 1.0 part by weight of silica, 0.2 to 2.0 parts by weight of glass fiber, 0.1 to 0.5 part by weight, yellow loam 0.1 to 1.0 part by weight, and silica fume 0.1 to 1.0 part by weight.

In the present invention, the acryl-based organic light-weight material is a powdery resin composed of an acrylate ester or a methacrylate ester resin, and a typical example thereof is a methyl methacrylate resin. The acrylic organic lightweight material used in the present invention is preferably contained in a range of 0.01 to 1.0 part by weight, more preferably 0.01 to 0.5 part by weight.

In the present invention, the porous pearlite can increase the water content due to porosity and improve the flowability, thereby making it possible to mechanize the concrete structure during the repairing work of the concrete structure through the water-repellent mortar composition. The porous pearlite used in the present invention is preferably contained in a range of 0.05 to 2.0 parts by weight, more preferably 0.1 to 1.0 part by weight.

In the present invention, it is preferable to use a cedar having an average particle diameter of 0.1 to 1.2 mm, which is advantageous for improving the flowability and compactness of the mortar composition. The silica sand used in the present invention is preferably contained in a range of 0.1 to 1.0 part by weight, more preferably 0.2 to 0.5 part by weight.

In the present invention, the glass fiber can reduce the surface crack (crack) during curing as well as increase the flexural strength, tensile strength, and is effective for initial stability after the mortar application and is used for the purpose of increasing initial dispersibility. The amount of the glass fiber used in the present invention is preferably in the range of 0.2 to 2.0 parts by weight, more preferably 0.5 to 1.0 parts by weight.

In the present invention, the neopentyl glycol has two alcohol groups symmetrically and two methyl groups at the alpha carbon position, and thus exhibits excellent reactivity to the esterification reaction. In the present invention, the neopentyl glycol may be used in the form of a flake consisting of 100% white crystals or a slurry composed of 90% neopentyl glycol and 10% water. The amount of neopentyl glycol used in the present invention is preferably in the range of 0.1 to 0.5 parts by weight, more preferably 0.2 to 0.4 parts by weight.

In the present invention, the loess is excellent in deodorization, antimicrobial and antifungal properties and has beneficial microorganisms and enzymes to block the characteristic odor of cement and alkaline substance and to decompose and remove the toxicity of cement. In the course of curing the mortar composition, the loess component strongly bonds between the fiber and the polyvinyl alcohol powder resin, the cement and the siliceous component, and the strong adhesion between each constituent constituting the structure and the binding force by penetration are exhibited, And to make it happen. The amount of the loess used in the present invention is preferably in the range of 0.1 to 1.0 part by weight, more preferably 0.2 to 0.8 part by weight.

In the present invention, the silica fume is an amorphous activated silica having an average particle diameter of about 0.1 to 0.5 mm, which is an almost spherical particle, and reacts with calcium hydroxide and changes to calcium hydrate at room temperature to have a super pozzolanic property. In addition, the silica fume improves dispersibility and water reducing effect by ball bearing effect by spherical particles and improves watertightness and strength by adhesion effect of silica fume between cement particles and improves adhesion of mortar, thereby reducing ground amount, inhibiting alkali silica reaction And improvement of chemical resistance. The amount of the silica fume used in the present invention is preferably in the range of 0.1 to 1.0 part by weight, more preferably 0.2 to 0.8 part by weight.

Next, the third component is prepared by mixing 0.01 to 2.0 parts by weight of fine alumina powder, 0.01 to 2.0 parts by weight of fine silica powder, and 0.01 to 2.0 parts by weight of polyvinyl alcohol powder. The alumina fine powder and the silica fine powder fill the polypropylene fiber and the acrylic organic lightweight material and promote the sintering of the mortar to increase the plasticity strength. In addition, the polyvinyl alcohol serves to increase the adhesive force of the mortar and to reduce the friction of the raw material during the press-feeding, thereby improving the dispersibility. In the present invention, the alumina fine powder and the silica fine powder are preferably contained in an amount of 0.01 to 2.0 parts by weight, more preferably 0.01 to 1.0 part by weight. In the present invention, the polyvinyl alcohol powder is preferably contained in an amount of 0.01 to 2.0 parts by weight, more preferably 0.01 to 1.0 part by weight.

The fourth component is prepared by mixing 0.1 to 5.0 parts by weight of polypropylene fiber, 0.1 to 3.0 parts by weight of water swellable polysaccharide polymer powder and 0.01 to 1.0 part by weight of PVC fiber.

In the present invention, the polypropylene fiber plays a role of enhancing the crack resistance due to shrinkage of the mortar and acts as a passage of heat when a fire occurs, thereby preventing the explosion phenomenon. In the present invention, the length of the polypropylene fiber is suitably in the range of 0.01 to 3.0 mm. The polypropylene fiber used in the present invention is preferably contained in a range of 0.01 to 3.0 parts by weight, more preferably 0.01 to 1.5 parts by weight.

In the present invention, the water swellable polysaccharide polymer powder serves to increase the material separation resistance of the mortar and to impart rheological properties. Further, the water swellable polysaccharide polymer powder is melted and decomposed in the event of a fire to form a discharge passage for vapor pressure. The water swellable polysaccharide polymer powder used in the present invention is preferably contained in the range of 0.1 to 3.0 parts by weight, more preferably 0.1 to 2.0 parts by weight.

In the present invention, the PVC fiber improves bending strength, reduces cracking, increases dispersibility, and serves as a passage of heat when a fire occurs, thereby preventing a thermal expansion phenomenon. In the present invention, it is suitable to use the PVC fibers having a length of 0.01 to 3.0 mm. The PVC fiber used in the present invention is preferably contained in a range of 0.01 to 1.0 part by weight, more preferably 0.1 to 2.0 parts by weight.

The prepared first to fourth components are mixed with the binder in an amount of 20 to 40 parts by weight as they are, and an appropriate amount of an additive such as a water reducing agent or defoaming agent and aggregate are mixed to prepare a mortar.

In the present invention, the first component to the fourth component are separately prepared and mixed with the binder and the aggregate to increase the efficiency of mixing, to achieve uniform mixing, and to prevent the function from decreasing due to mutual reaction. In addition, when applied to mortar, it improves the initial strength of the mortar and sufficiently exhibits the compressive strength and bending strength characteristics. In addition, it improves the chemical resistance and improves the fire resistance by securing the vapor pressure discharge passage in the case of fire, This is to enhance insulation.

In the present invention, general cement may be used as the binder, or special binders may be used, and there is no particular limitation.

The cement may be selected from the group consisting of portland cement, white portland cement, alumina cement, weatherproof cement, and aged steel cement.

In addition, the special binders are made of artificial marble waste powder, which is an industrial by-product, and also have an effect of recycling waste resources.

Specifically, the special binder includes 100 parts by weight of artificial marble waste powder, 20 to 50 parts by weight of a slag-containing mixture, 20 to 40 parts by weight of gypsum or flue gas desulfurizing agent, 10 to 30 parts by weight of sintered magnesia cement, 20 to 50% by weight of a cement having a diameter of 2 to 20 parts by weight of ammonium phosphate monobasic; 30 to 60 wt% portland cement; 5 to 20% by weight of a cellulose fiber; And 5 to 10% by weight of an EVA resin.

The artificial marble waste powder for use as a source of Al ₂ O ₃ in the present invention is a building waste generated in the form of powder in a polishing process of an artificial marble made of an acrylic resin or an unsaturated polyester resin, Aluminum hydroxide. The aluminum hydroxide which is the main component of the artificial marble waste powder is desorbed at high temperature to be made aluminum oxide so that it is combined with CaO or calcium sulfate to form calcium aluminum Nate and calcium sulfoaluminate are produced to exhibit quickness.

The slag-containing mixture in the present invention specifically, a specific surface area of 6,000 to 7,000 cm ² / g is 65 to 80% by weight blast furnace slag, lime 10 to 20% by weight, 5 to 15% by weight of gypsum and 8,000cm ² / g to about 20,000 cm ² / g of the powder have an average particle diameter of 1 ~ 10㎛ the kiln dust with a specific surface area of 10,000 through the mixing and grinding mechanochemical activation process of a mixture consisting of 5 to 20% by weight in a vibration mill to about 20,000 cm ² / g. < / RTI > Hereinafter, each component of the slag-containing mixture used in the present invention will be described in detail.

Firstly, the blast furnace slag is produced as a by-product when producing pig iron in a steel mill, and is formed into an amorphous state by quenching, and the basicity is in the range of 1.6 to 2.0. The blast furnace slag is generally CaO 40 to 50 wt%, MgO 1 to 10 wt%, Al ₂ O ₃ 10 to 25% by weight and SiO ₂ 33 to 38% by weight. The blast furnace slag is also used as an admixture for concrete. The blast furnace slag used as an admixture for concrete has a specific surface area of about 4,000 to 5,000 cm ² / g. In the present invention, the blast furnace slag is ground using a ball mill or the like And has a specific surface area of about 6,000 to 7,000 cm ² / g. The blast furnace slag is added in an amount of 65 to 80% by weight. When the blast furnace slag is less than 65% by weight, the reactivity increases due to the increase in the weight percentage of lime and gypsum, The initial reaction and the settling time are delayed, which makes it difficult to secure initial strength.

The lime and gypsum are used as an activator. When the slag powder is contacted with water, a dense impermeable acid film is formed on the surface of slag particles. In order to continue the reaction, it is necessary to destroy the acid film by the activator. Is used.

When the dissolution reaction occurs on the surface of the blast furnace slag by the activation action of the lime and the gypsum, the insoluble matter precipitates from the solution and starts to cure. In this case, the blast furnace slag is composed of Ca (OH) ₂ To form a hydrate. The hydrate of the blast furnace slag may contain calcium silicate hydrate by the activating agent, may form ettringite or aluminum hydroxide, thereby compensating for shrinkage of the cured body, forming dense texture, and contributing to increase the compressive strength . In addition, gypsum serves as a stimulant in the latent hydraulic reaction, which is a characteristic of the slag fine powder, thereby enhancing the reactivity of the slag fine powder and serving as an auxiliary agent for further enhancing the strength.

If less than 10% by weight, the amount of Ca (OH) ₂ that contributes to the hydration of the blast furnace slag powder and the formation of etyne zeite is insufficient, If the Ca (OH) ₂ is added in an amount exceeding 20% by weight, Ca (OH) ₂ remaining unreacted may act as a cause of swelling and cause a problem.

The gypsum may be a gypsum of any one of anhydrous gypsum, semi-gypsum or alum-gypsum, or a mixture of two or more kinds of gypsum. Preferably, the gypsum is added in an amount of 5 to 15 wt% The amount of the nitrile is excessively increased. When the amount of the nitrile is more than 15% by weight, the amount of the nitrile is excessively large, which may cause expansion of the structure and inhibition of smooth strength development.

In the present invention, the kiln dust is a particulate dust powder which is fed in the cement manufacturing process. However, the kiln dust is fed back during the process so that a certain amount of the dust is recirculated. However, Mixing of minor components or uneven mixing during recycling can cause process instability or product quality fluctuation. These kiln dusts contain trace amounts of sulfur trioxide (SO ₃ ), alkali (K ₂ O), and salt (NaCl), which are the main ingredients of CaCO ₃ as irritant components of the slag fine powder.

In the present invention, since blast furnace slag powder, lime and plaster, which are industrial byproducts, as well as kiln dust, which is a particulate dust powder blended in the cement manufacturing process, are mixed, it is possible to reduce the cost and promote early hydration, And durability over a long period of time can be ensured.

In the present invention, it is preferable that the kiln dust has a powdery degree of 8,000 cm ² / g or more, more preferably 8,000 to 20,000 cm ² / g and has an average particle diameter of 1 to 10 μm in an amount of 5 to 20 wt% desirable.

The blend of blast furnace slag, gypsum, lime and kiln dust is subjected to mechanochemical activation treatment, wherein the mechanochemical activation treatment is carried out by mixing and pulverizing in a vibration mill for 5 to 60 minutes, more preferably for 10 to 30 minutes .

In the present invention, the mechanochemical activation treatment changes the physico-chemical properties of the material by changing the bonding state of the material by a mechanical grinding process. When mixed and pulverized, uniform mixing is possible in the grinding operation, There is an advantage to proceed at the same time. That is, the mechanical collision in the milling system by the mechanochemical activation process develops elasticity, plasticity and shear deformation, causing destruction of the particles, non-crystallization, and even chemical reaction in the solid state.

Generally, in the field of cement milling, a fine mill such as a ball mill or a roller mill is used. In the case of a ball mill, in a rotating cylinder, the milling medium moves upwardly along the inner wall of the cylinder by centrifugal force, The roller mill is a system in which 3 to 4 rollers are rotated in a mill on a disk and the whole is revolved to use a principle in which the pulverized material is crushed by compression and frictional force between the roller, the disk and the inner wall. On the other hand, the vibrating mill is a system in which a whole mill is vibrated by an eccentric circle, and a grinding medium such as a ball or bar in the mill simultaneously transmits impact force and frictional force to the grinding product to grind the grinding product to a micron unit, By supplying a large amount of pulverizing energy to the pulverization raw material. In other words, vibration mill is a pulverizing system suitable for mechanochemical activation process. It can pulverize target powder in a shorter time than conventional pulverizing media such as ball mill, and it gives shear frictional force and impact force at the same time. Therefore, In the case of pulverization, the fine particles of the product are surface-treated to increase the affinity between the particles, resulting in an increase in chemical activity.

In the present invention, the mechanochemical treatment is preferably performed in a vibration mill for 5 minutes to 60 minutes, more preferably 10 minutes to 30 minutes. This is because it is the most ideal time to treat the specific surface area of the mixture of the present invention from 10,000 to 20,000 cm ² / g.

Also, in the present invention, the phosphorus-containing diatomaceous earth or the flue gas desulfurizing agent included in the hydrous cement may be used as a source of CaSO ₄ . It is preferable that the content is 20 to 40 parts by weight based on 100 parts by weight of artificial marble waste powder. When it is used in an amount of less than 20 parts by weight, the calcium sulfoaluminate component is not sufficiently produced and it is difficult to improve the initial strength due to densification of the structure. When the amount exceeds 40 parts by weight, unreacted gypsum remains and is inefficient.

In the present invention, the sintered magnesia cement to be included in the above-mentioned cement comprises the sintered magnesia cement sintered at about 800 to 1500 ° C. The sintered magnesia cement has excellent fast-curing properties and is excellent in reactivity with cations, thereby enhancing adhesion strength with concrete. The sintered magnesia cement contained in the cement according to the present invention is preferably contained in the range of 10 to 30 parts by weight based on 100 parts by weight of the artificial marble waste powder.

Further, ammonium monophosphate is further used as a material for activating the sintered magnesia cement. The formula of the first ginseng ammonium is NH ₄ H ₂ PO ₄ , is stable in air, has a specific gravity of about 1.8, and has a pH of 4.3 to 5.0 in an aqueous solution. The sintered magnesia cement contained in the hollow cement according to the present invention is preferably contained in the range of 5 to 20 parts by weight based on 100 parts by weight of the artificial marble waste powder.

In order to produce the above-mentioned cemented cement, artificial marble waste powder, a slag-containing mixture, a phosphorus acid busulfide resin gypsum or an exhaust gas desulfurization water gypsum, sintered magnesia cement and ammonium phosphate monobasic are mixed, It is preferable to use a material obtained by pulverizing the mixture to have an average particle size of 10 to 20 탆 after firing for 1 hour to exhibit fastness suitable for use in repairing and reinforcing concrete structures and to improve the denseness of the structure when applied to mortar Do. If the average particle size is smaller than the above range, the fastness is improved to a greater extent, but it is inefficient because it is necessary to use a retarder for the pot life to apply to the mortar. In the present invention, it is preferable to use 20 to 50% by weight of the whole binder component. If it is less than 20% by weight, the mortar strength is lowered and fast curing time can not be obtained. If it exceeds 50% by weight, fast curing characteristics can be obtained, but cracks due to over expansion can occur.

In the present invention, among the binder components, the portland cement is used for expressing the late strength of the mortar. It is preferable to use one type of portland cement, and it is preferable to use 30 to 60 wt% of the total binder components.

In the present invention, the cellulose fibers included in the binder component are used for improving the flexural strength and tensile strength and reducing surface cracking during curing, and are effective for initial stability after the mortar application and for increasing initial dispersibility. In the present invention, the cellulose fibers are preferably used in an amount of 5 to 20% by weight in the binder. If the content is less than 5% by weight, the effect of improving the tensile strength and the bending strength is insignificant. If the content is more than 20% by weight, workability and economical efficiency may be deteriorated.

In the present invention, the EVA resin included in the binder component serves to increase the fluidity and workability of the mortar composition before curing. In the cured state of the mortar composition, the EVA resin increases surface adhesion, increases cohesive strength, It has the effect of improving flexibility and increasing water resistance. In the present invention, the EVA resin is preferably contained in the binder in an amount of 5 to 10% by weight. The content of the EVA resin is less than 5 wt% and the effect of strengthening the surface adhesion is insignificant. If it exceeds 10 wt%, the hydration reaction is inhibited and the strength is lowered.

In the present invention, a known water reducing agent may be used for the water-cement ratio reduction in the mortar composition, and a known defoaming agent may be used to prevent the occurrence of large bubbles. Aggregates can be used as a filler. It is not particularly limited in the present invention.

Further, it is preferable that the aggregate is used by mixing the No. 4 and the No. 6 in a weight ratio of 30:70 to 50:50 in order to prevent the rebound and increase the filling property.

In addition, the present invention may further comprise additives such as the dispersing agent, retarding agent, fluidizing agent and the like, if necessary.

The fourth step is a step of applying the refractory mortar according to the present invention to a concrete structure, and may be performed using spray or trowel or by a mixing pumping device.

It is preferable that the mortar composition is applied at a time of 5-15 mm for the first casting, 20-50 mm for the second casting and the third casting, and 5-15 mm for the final casting at the fourth step of the repairing (spraying) And is more preferable for improving durability.

Next, a refractory coating agent is applied to the surface of the applied refractory mortar to enhance fire resistance.

The refractory coating agent to be used in the present invention may include 10 to 50 wt% of an epoxy resin, 5 to 40 wt% of a polymethyl methacrylate resin, 1 to 25 wt% of a diluent, 0.1 to 15 wt% of a flocculant, 1 to 20 wt% of an inorganic filler 1 to 20% by weight of a water-soluble oil, 1 to 10% by weight of an emulsifier, 1 to 10% by weight of an emulsifier, 0.1 to 5% by weight of an accelerator, 0.05 to 20% by weight of an emulsifier and 10 to 80% 5 to 20% by weight of water and 50 to 90% by weight of water are mixed to prepare an aqueous solution. 5 to 50 parts by weight of a polyamide and 0.1 to 40 parts by weight of an amine compound are mixed with 100 parts by weight of the obtained aqueous solution to obtain a curing agent component To 50 parts by weight of a white cement and 1 to 15 parts by weight of a powder component mixed with white cement and limestone powder in an amount of 10 to 90: 90 to 10 parts by weight, respectively, is preferably used. Particularly, Application and refractory mortar It is desirable to integrate the fire-resistant coating.

In the present invention, since the refractory coating agent has a thermal expansion coefficient and a drying shrinkage rate similar to those of the refractory mortar according to the present invention, it has excellent adhesion with refractory mortar and improved durability.

The third step may further include applying a component obtained by mixing the acrylic resin with the basalt fiber powder on the surface to which the adhesive is applied. In this case, since adhesion performance between the mortar and concrete can be further improved, It is possible to prevent the mortar from falling off due to shear stress at the interface where the refractory mortar is applied.

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

[Example]

The first component, the second component, the third component and the fourth component were prepared in accordance with the formulation composition (unit: parts by weight) in Table 1 below, and the components thus prepared were mixed with a binder (cement) , And the resulting mixture was mixed with water reducing agent, antifoaming agent and sand according to the composition shown in the following Table 1 and mixed with water to prepare a refractory mortar.

The physical properties (slurry density, rebound amount, compressive strength, bending strength and adhesion strength) of the mortar were measured using the refractory mortar thus obtained according to the standard of KS F 4042 2007. The acid resistance of the specimens cured for 28 days was measured using 5% After 7 days of immersion, weight loss and compressive strength reduction were measured. The table is shown in Table 2 below. The heat resistance was measured at 900 ° C and then the residual compressive strength was measured.

[Comparative Example]

The mortar was produced in the same manner as in Example 1 except that the proportions of the respective admixtures were varied according to the composition shown in Table 1. The properties were evaluated in the same manner as in Comparative Examples 1 and 2. [

As Comparative Example 3, the respective components were mixed in the same proportions as in Example 1, and mortar was prepared by batchwise blending the components from the top in any order, and the properties were evaluated in the same manner.

Raw material Example 1 Example 2 Comparative Example 1 Comparative Example 2 The first component CSA type hard swelling agent 3.0 2.0 3.0 3.0 Fine powder of blast furnace slag 7.0 7.0 7.0 8.0 Fly ash 3.0 4.0 4.0 4.0 The second component Acrylic-based organic lightweight material 0.5 1.0 0.5 0.5 Porous pearlite 0.5 1.0 0 0.5 Silica sand 2.0 1.0 0 2.0 Glass fiber 0.5 0.5 0 0.5 Neopentyl glycol 0.3 0.4 0 0 ocher 0.5 0.4 0 0 Silica fume 0.4 0.5 0 0 The third component Alumina fine powder 0.5 0.7 0.5 0.5 Fine powder of silica 0.5 0.8 0.5 0.5 Polyvinyl alcohol powder 1.0 0.5 1.0 1.0 The fourth component Polypropylene fiber 2.0 3.0 2.0 2.0 Water swellable polysaccharide polymer powder 1.0 1.5 0 0 PVC fiber 0.5 0.5 0 0 cement Type 1 portland cement 25.0 25.0 27.0 27.5 Other Water reducing agent 0.3 0.3 0.3 0.3 Defoamer 0.2 0.2 0.2 0.2 sand 56.0 56. 56.0 56.0 water 18.0 18.0 18.0 18.0

Item unit Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Slurry density 1.89 1.88 2.00 1.90 1.85 Rebound amount % 4.9 4.5 12.0 11.6 13.0 Compressive strength N / mm ² 55.5 57.3 51.6 51.4 51.2 Flexural strength N / mm ² 12.3 13.0 12.2 12.3 11.1 Bond strength N / mm ² 2.5 2.3 2.0 1.0 1.2 Acid resistance (5% sulfuric acid solution) Weight reduction % -0.01 -0.01 -0.35 -1.56 -1.70 Compressive strength N / mm ² 48.8 53.6 48.0 44.5 41.5 decrease% 5.0 4.6 12.9 16.0 16.3 Heat resistance Remaining compressive strength N / mm ² 47.5 48.5 28.3 26.0 30.0

As shown in Table 2, the mortar composition according to the present invention has the same physical properties as those of the mortar composition prepared according to the comparative example, namely, the slurry density, the bending strength, the compressive strength and the adhesion strength are equal to or more than that, It can be confirmed that the efficiency of the construction is excellent and in particular, it is remarkably excellent in terms of chemical resistance (acid resistance) and fire resistance (heat resistance). In the case of Comparative Example 3, the mortar was prepared by simply mixing the respective components, and the physical properties of the mortar were poor. This is because the mixing of the components is not efficiently and uniformly carried out, and therefore, the components are not sufficiently functional, and the functions are reduced due to the mutual interactions.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, The present invention is not limited thereto.

Claims (7)

(a) a first step of chipping, grinding, and cleaning the concrete structure requiring repairing, followed by high pressure cleaning;
(b) a second step of applying the rust preventive agent to the exposed reinforcing bars after the concrete is dropped in the first step;
(c) a third step of applying an adhesive to the surface of the concrete structure and the reinforcing bar after the second step;
(d) 1 to 5 parts by weight of a CSA quick-setting swelling agent, 2 to 10 parts by weight of blast furnace slag powder and 1 to 5 parts by weight of fly ash are mixed with 20 to 40 parts by weight of the binder on the surface of the surface to which the adhesive is applied 0.01 to 1.0 part by weight of porous organic peroxide, 0.05 to 2.0 parts by weight of porous perlite, 0.1 to 1.0 part by weight of silica sand, 0.2 to 2.0 parts by weight of glass fiber, 0.1 to 0.5 parts by weight of neopentyl glycol, A third component obtained by mixing 0.01 to 2.0 parts by weight of a fine alumina powder, 0.01 to 2.0 parts by weight of a fine silica powder and 0.01 to 2.0 parts by weight of a polyvinyl alcohol powder, A fourth component composed of 0.1 to 5.0 parts by weight of a propylene fiber, 0.1 to 3.0 parts by weight of a water-swellable polysaccharide polymer powder and 0.01 to 1.0 part by weight of a PVC fiber, is sprayed to form a cross section, step; And
(e) a fifth step of applying a refractory coating agent on the surface of the refractory mortar composition applied by spraying to cure the mortar composition,
In the fourth step, the binder comprises 100 parts by weight of artificial marble waste powder, 20 to 50 parts by weight of a slag-containing mixture, 20 to 40 parts by weight of gypsum or flue gas desulphurizing admixture, 10 to 30 parts by weight of sintered magnesia cement And 20 to 50% by weight of a cemented latex comprising 5 to 20 parts by weight of ammonium phosphate; 30 to 60 wt% portland cement; 5 to 20% by weight of a cellulose fiber; And 5 to 10% by weight of an EVA resin,
In the fifth step, the refractory coating agent comprises 10 to 50 wt% of an epoxy resin, 5 to 40 wt% of a polymethyl methacrylate resin, 1 to 25 wt% of a diluent, 0.1 to 15 wt% of a flocculant, 1 to 20 wt% 1 to 20% by weight of a water-soluble oil, 1 to 10% by weight of an emulsifier, 5 to 10% by weight of an emulsifier, 5 to 20% by weight of an emulsifier, 0.1 to 5% by weight of an accelerator, 0.05 to 20% To 20% by weight of water and 50 to 90% by weight of water to prepare an aqueous solution, mixing 5 to 50 parts by weight of a polyamide and 0.1 to 40 parts by weight of an amine compound based on 100 parts by weight of the obtained aqueous solution, 50 weight ratio, and 1 to 15 parts by weight of a powder component obtained by mixing white cement and limestone powder in a weight ratio of 10 to 90: 90 to 10, respectively, is applied to the refractory mortar composition before curing,
The PVC fiber in the fourth component used in the fourth step has a range of 0.01 to 3 mm so as to serve as a passage of heat when a fire occurs,
The step of further applying a component obtained by mixing the acrylic resin with the basalt fiber powder on the surface coated with the adhesive in the third step further improves the adhesion performance between the refractory mortar composition and the concrete to increase the shear stress at the interface Thereby preventing deterioration of the mortar caused by the fireproofing of the concrete structure.
delete delete The method according to claim 1, wherein the slag-containing mixture having a specific surface area of 6,000 to 7,000 cm ² / g is 65 to 80% by weight blast furnace slag, lime 10 to 20% by weight, 5 to 15% by weight of gypsum and 8,000cm ² / g to about 20,000 cm ² / g of the powder have an average particle diameter of 1 ~ 10㎛ the kiln dust with a specific surface area of 10,000 through the mixing and grinding mechanochemical activation process of a mixture consisting of 5 to 20% by weight in a vibration mill to about 20,000 cm ² / g. < / RTI > A method of refractory repair work in a concrete structure, comprising:
The method according to claim 1, wherein in the fourth step, the second component further comprises a silicon powder component consisting of n-octyltriethoxysilane at a weight ratio of 1 to 5.
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