KR102531519B1 - Manufacturing method of fiber reinforced plastic reinforcement - Google Patents

Abstract

The present invention relates to a method for manufacturing fiber-reinforced plastic reinforcement. More specifically, the present invention relates to a method of manufacturing fiber-reinforced plastic reinforcement which not only has excellent corrosion resistance, heat resistance, and anti-corrosive characteristics, but also exhibits very high mechanical strength and can replace reinforcing bars conventionally used as concrete reinforcing bars, and which does not require separate reinforcement construction and thus achieves improved economic feasibility. To this end, the manufacturing method includes the steps of: preparing reinforcing fibers containing at least one selected from the group consisting of glass fibers, carbon fibers, aramid fibers, hybrid fibers, and combinations thereof; manufacturing a synthetic resin composition by mixing a synthetic resin and a curing agent; impregnating the reinforcing fibers into the synthetic resin composition; and curing the synthetic resin composition impregnated with the reinforcing fibers at a temperature range of 120 to 240℃ to form a fiber-reinforced plastic reinforcement.

Description

Method for manufacturing fiber-reinforced plastic reinforcing materials {MANUFACTURING METHOD OF FIBER REINFORCED PLASTIC REINFORCEMENT}

The present invention relates to a method for manufacturing a fiber-reinforced plastic reinforcing material, and more particularly, has excellent corrosion resistance, heat resistance, and corrosion resistance, and exhibits very high mechanical strength, which can replace reinforcing bars used as existing concrete reinforcing bars. It relates to a method for manufacturing a fiber-reinforced plastic reinforcing material, which does not require reinforcement construction and can obtain an economical effect.

In general, since the surface of a concrete structure including reinforcing bars is usually exposed to the outside, it deteriorates over time, resulting in poor aesthetics, and cracks occur on the surface to reduce the strength and rigidity of the structure. In addition, when moisture penetrates into such cracks, additional cracks are more easily caused, and the penetrated moisture corrodes the reinforcing bars inside the concrete.

In addition, concrete structures may suffer from serious reinforcement corrosion problems due to the effects of snow removal materials or seawater environments. In the case of reinforcing bars included in concrete structures, it is emerging as a problem that serious corrosion cannot be avoided in a chlorinated concrete environment even if epoxy coating is applied.

In this way, when rust occurs due to corrosion of the reinforcing bars, the strength of the reinforcing bars is lowered and the durability of the building is lowered. do. In addition, there are problems such as cracks and leaks in the building wall due to the decrease in elasticity and tensile force when the high-rise building is shaken, and inconvenient installation, transportation, and storage due to heavy weight during work.

Accordingly, in order to improve performance such as durability, the use of reinforcing materials including metal fibers, organic fibers, and natural fibers has emerged. Representative fiber-containing reinforcing materials currently used are high-performance nylon-based and PVA-based reinforcing materials, which exhibit hydrophilic properties and have good compatibility with mortar, so that cracks or warping can be prevented and the crack suppression effect of concrete is excellent.

However, these reinforcing materials have problems such as poor contact with concrete and low mechanical strength due to a decrease in tensile strength, particularly shear properties, etc. compared to production costs.

Republic of Korea Patent Registration No. 10-1892506

The present invention is to solve the above problems, to provide a method for manufacturing a fiber-reinforced plastic reinforcing material that has very high mechanical strength and is excellent in corrosion resistance, heat resistance, and corrosion resistance and can replace reinforcing bars used as existing concrete reinforcing bars. do.

The above and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

The above object is to prepare a reinforcing fiber comprising at least one selected from the group consisting of glass fibers, carbon fibers, aramid fibers, hybrid fibers, and combinations thereof; preparing a synthetic resin composition by mixing a synthetic resin and a curing agent; impregnating the reinforcing fibers into the synthetic resin composition; and forming a fiber-reinforced plastic reinforcing material by curing the synthetic resin composition impregnated with the reinforcing fibers at a temperature range of 120° C. to 240° C.

Specifically, the reinforcing fiber may be characterized in that it is broken into a plurality of strands and spread without a certain directionality (Non-Axial Type).

Specifically, the curing agent may include at least one selected from the group consisting of amine-based, acid anhydride-based, polyamide-based, polyamide-amine-based, phenol-based, and carboxylic acid polyesters.

According to the present invention, the mechanical strength including tensile strength, yield strength, modulus of elasticity, etc. is very excellent, so it can replace the reinforcing bar used as the existing concrete reinforcing bar, exhibits improved adhesion strength, and has excellent adhesion to concrete , it is possible to manufacture a fiber-reinforced plastic reinforcing material that exhibits a low coefficient of thermal expansion and can prevent deformation of the structure due to rapid temperature change during construction.

However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a flow chart showing a method for manufacturing fiber-reinforced plastics according to an embodiment of the present invention.
2 (a) and (b) are images showing a fiber-reinforced plastic according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. These examples are only presented as examples to explain the present invention in more detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. .

In addition, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art to which this invention belongs, and in case of conflict, this specification including definitions of will take precedence.

In order to clearly explain the proposed invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification. And, when a certain component is said to "include", this means that it may further include other components without excluding other components unless otherwise stated. Also, a “unit” described in the specification means one unit or block that performs a specific function.

In each step, the identification code (first, second, etc.) is used for convenience of description, and the identification code does not describe the order of each step, and each step does not clearly describe a specific order in context. It may be performed differently from the order specified above. That is, each step may be performed in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

Hereinafter, embodiments and embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, it may not be limited to these implementations and examples and figures herein.

In one aspect of the present application, preparing a reinforcing fiber comprising at least one selected from the group consisting of glass fibers, carbon fibers, aramid fibers, hybrid fibers, and combinations thereof; preparing a synthetic resin composition by mixing a synthetic resin and a curing agent; impregnating the reinforcing fibers into the synthetic resin composition; and forming a fiber-reinforced plastic reinforcing material by curing the synthetic resin composition impregnated with the reinforcing fiber at a temperature range of 120°C to 240°C.

The fiber-reinforced plastic reinforcing material according to the present invention has very excellent mechanical strength including tensile strength, yield strength, modulus of elasticity, etc., so it can replace reinforcing bars used as existing concrete reinforcing bars, and exhibits improved adhesion strength to match with concrete. It has excellent adhesion and exhibits a low coefficient of thermal expansion, so it has the effect of preventing deformation of the structure due to rapid temperature change during construction.

Hereinafter, a method for manufacturing a fiber-reinforced plastic reinforcing material according to the present invention will be described in detail with reference to FIG. 1 .

First, a reinforcing fiber is prepared as a component of the fiber-reinforced plastic reinforcing material.

In one embodiment, the reinforcing fiber as a component of the fiber-reinforced plastic reinforcing material is included to impart effects such as water resistance and chemical resistance with high mechanical strength, for example, glass fiber, carbon fiber, aramid It may include at least one selected from the group consisting of fibers, hybrid fibers, and combinations thereof.

In one embodiment, the reinforcing fiber may be characterized in that it is broken into a plurality of strands and spread without a certain direction (Non-Axial Type). For example, the reinforcing fiber may include cutting each fiber strand to a length of about 1 to 50 mm and spreading the cut pieces without directionality. If the reinforcing fiber is cut and included in less than about 1 mm, the effect of improving mechanical strength, water resistance and chemical resistance due to the inclusion of the reinforcing fiber may not be sufficiently exhibited, and if the length exceeds about 50 mm Workability may decrease when manufacturing stiffeners.

Next, a synthetic resin composition is prepared by mixing a synthetic resin and a curing agent.

In one embodiment, the synthetic resin as a component of the fiber-reinforced plastic reinforcing material exhibits higher water resistance and corrosion resistance than reinforcing bars, and has a low coefficient of thermal expansion, so it is not easily deformed by rapid temperature change when used as a reinforcing material for concrete structures. have However, the synthetic resin has low mechanical strength, and in order to compensate for this, the mechanical strength may be supplemented by impregnating reinforcing fibers.

In one embodiment, the synthetic resin is an ethylene vinyl acetate resin, a polyester resin, an unsaturated polyester resin, a polyurethane resin, an acrylic resin, an epoxy resin, a polypropylene resin, a polyamide resin, a polyolefin resin, and combinations thereof It may be characterized in that it includes one or more selected from the group consisting of. Preferably, the synthetic resin may include an unsaturated polyester resin.

In one embodiment, the curing agent is mixed with the synthetic resin and included to promote curing by heat, for example, amine-based, acid anhydride-based, polyamide-based, polyamide-amine-based, phenol-based and carboxylic acid It may be characterized by including one or more selected from the group consisting of polyester. Specifically, the curing agent may include an amine type, and preferably may include [4,4'-methylenebis-(2,6-diethylaniline)] (MBDA).

In one embodiment, the synthetic resin composition may include about 75 to 95% by weight of the synthetic resin and about 5 to 25% by weight of the curing agent. If the synthetic resin is less than about 75% by weight and the curing agent is about 25% by weight or more, the curing speed is too fast and workability may deteriorate, and if the synthetic resin exceeds about 95% by weight or the curing agent is less than about 5% by weight In this case, curing may not be performed sufficiently. Preferably, the synthetic resin composition may include about 75 to about 90% by weight of the synthetic resin and about 5 to 20% by weight of the curing agent.

In one embodiment, the fiber-reinforced plastic reinforcing material may further include magnesium chloride. For example, the fiber-reinforced plastic reinforcing material is added by further mixing magnesium chloride for the purpose of improving workability by increasing the curing speed of the synthetic resin composition in the step of preparing the synthetic resin composition by mixing the synthetic resin and the curing agent it could be The magnesium chloride may be included in about 0.01 to 1% by weight of the synthetic resin composition, and if the magnesium chloride is included in less than about 0.01% by weight, it may take a long time to cure the composition, exceeding about 1% by weight. If the curing speed is too fast, workability may deteriorate.

In one embodiment, the fiber-reinforced plastic reinforcing material may further include yttria-stabilized zirconia. For example, the fiber-reinforced plastic reinforcing material is added by additionally mixing yttria stabilized zirconia for the purpose of improving the mechanical strength of the fiber-reinforced plastic reinforcing material produced later in the step of preparing a synthetic resin composition by mixing a synthetic resin and a curing agent. may be included. The yttria-stabilized zirconia (YSZ) is a ceramic material made stable at room temperature by adding yttrium oxide (yttria) to zirconium oxide (zirconia), and has very high mechanical strength, resulting in surface hardness of fiber-reinforced plastic reinforcements. It can show the effect of maintaining the construction effect for a long time during construction using reinforcing materials by showing improved chemical resistance and acid resistance while improving

In one embodiment, the yttria-stabilized zirconia may be included in about 0.1 to 3% by weight of the synthetic resin composition. If the yttria-stabilized zirconia is included in an amount of less than about 0.1% by weight, the effect resulting from the inclusion may not be sufficiently exhibited, and if it exceeds about 3% by weight, mixing with other components may be inhibited.

In one embodiment, the fiber-reinforced plastic reinforcing material may further include modified starch. For example, in the step of preparing a synthetic resin composition by mixing a synthetic resin and a curing agent, the fiber-reinforced plastic reinforcing material improves adhesion between the synthetic resin and reinforcing fibers to be impregnated later and adds modified starch to increase the stability of the composition itself. It may be further included by mixing with. For example, the modified starch may include at least one selected from the group consisting of cationic starch, amphoteric starch, acetic acid starch, crosslinked starch, hydroxypropylated starch, esterified starch, and combinations thereof. However, it is not limited thereto.

In one embodiment, the modified starch may be included in about 0.1 to 3% by weight of the synthetic resin composition. If the modified starch is included in an amount of less than about 0.1% by weight, the effect resulting from the inclusion of the modified starch may not be sufficiently exhibited, and if it exceeds about 3% by weight, mixability with other components may be impaired.

Next, the reinforcing fiber is impregnated into the synthetic resin composition prepared by mixing the synthetic resin and the curing agent. For example, the reinforcing fibers may pass through a tank containing the synthetic resin composition and the reinforcing fibers may be impregnated with the synthetic resin composition.

Next, a fiber-reinforced plastic reinforcing material including a synthetic resin composite is formed by injecting the synthetic resin composition impregnated with the reinforcing fibers into a predetermined mold and curing it by applying heat.

In one embodiment, the predetermined mold may be manufactured in a shape similar to the shape of a reinforcing bar used in manufacturing a conventional concrete structure, for example, a core having a cylindrical shape and a rib integrally formed with the core It may contain. Specifically, the rib may be formed inclined at a predetermined angle with respect to the longitudinal direction of the cylindrical core, and the thickness of the rib may extend from the outer surface of the core to a constant thickness.

In one embodiment, the curing may be performed by compressing by applying heat in a temperature range of about 120 °C to 240 °C. If the curing is performed at a temperature range of less than about 120 ° C, the curing of the composition may not be sufficiently performed, and if the temperature exceeds about 240 ° C, the mechanical strength of the fiber-reinforced plastic reinforcing material produced due to excessive heat may rather decrease. there is. Preferably, the curing may be performed at a temperature range of about 180 °C to 210 °C.

In one embodiment, it may further include coating the mortar composition on the fiber-reinforced plastic reinforcing material prepared above. The coating is to improve adhesion between the fiber-reinforced plastic reinforcing material and the mortar included in the concrete structure, and specifically, may be performed by spray-coating a mortar composition on the surface of the fiber-reinforced plastic reinforcing material and drying it.

In one embodiment, the mortar composition may include about 45% by weight of marble powder, about 20% by weight of Portland cement, about 15% by weight of ultra-fast cement, about 10% by weight of stone powder, and about 10% by weight of aggregate. .

In one embodiment, it may further include coating a synthetic resin composite on the fiber-reinforced plastic reinforcing material prepared above. The coating is for improving adhesion between the fiber-reinforced plastic reinforcement material and cement, or between the fiber-reinforced plastic reinforcement material and concrete. Specifically, the fiber-reinforced plastic reinforcement material is immersed in a composition containing a synthetic resin composite, or the fiber-reinforced plastic reinforcement material It may be performed by coating a composition containing the synthetic resin composite on and drying it.

In one embodiment, the synthetic resin composite may include a mixture of a metal or metal oxide with a synthetic resin. For example, the synthetic resin may include polyurethane or polyacrylic, and the metal or metal oxide may be a transition metal such as Fe, Ti, Al or the like or FeO, Fe ₂ O ₃ , TiO ₂ , Al ₂ O ₃ It may contain a metal oxide. Specifically, the synthetic resin composite may include a composite obtained by mixing polyurethane and Fe ₂ O ₃ .

In one embodiment, the drying may be performed by a method selected from the group consisting of hot air drying, freeze drying, natural drying, cold air drying, and combinations thereof, and specifically performed through cold air drying it could be

Hereinafter, the configuration of the present invention and its effects will be described in more detail through specific examples and comparative examples. However, these examples are for explaining the present invention in more detail, and the scope of the present invention is not limited to these examples.

[Example 1]

First, after preparing a carbon fiber cut to a length of about 40 mm, it was impregnated with a synthetic resin composition prepared by mixing the components of Table 1 below. Thereafter, the synthetic resin composition impregnated with carbon fiber was injected into a mold and cured at a temperature of 190° C. to prepare a cylindrical reinforcing material including ribs. The prepared reinforcing material was named Example 1.

[Example 2 and Example 3]

A mortar composition prepared in the same manner as in Example 1, but containing 45% by weight of marble powder, 20% by weight of Portland cement, 15% by weight of ultra-fast cement, 10% by weight of stone powder, and 10% by weight of aggregate in a cured reinforcing material. The coating was repeated twice, and a reinforcing material was prepared by further including a process of additionally coating a coating agent in which 15% of Fe ₂ O ₃ was mixed with a polyurethane resin. Examples 2 and 3 were respectively named according to the components of the synthetic resin composition prepared.

Synthetic resin composition (% by weight) Example 1 Example 2 Example 3 unsaturated polyester resin 90.00 86.50 84.50 [4,4'-methylenebis-(2,6-diethylaniline)] 10.00 10.00 10.00 magnesium chloride - 1.00 1.00 Yttria Stabilized Zirconia - 2.50 2.50 Modified Starch (Esterified Starch) - - 2.00 Sum 100.00 100.00 100.00

[Comparative Example 1]

As a reinforcing bar used in concrete structures, a circular steel bar having a diameter of about 10 mm was prepared and named Comparative Example 1.

[Comparative Example 2]

After immersing the powdered glass fiber in polyurethane resin, it was injected into a mold and cured at a temperature of 190° C. to prepare a cylindrical reinforcing material including ribs. The prepared reinforcing material was named Comparative Example 2.

[Experimental Example 1: Mechanical strength measurement]

Weight, tensile strength, modulus of elasticity, and adhesive strength for each of the reinforcing materials prepared in the above Examples and Comparative Examples were measured according to KS F 4042-2012, and the results are shown in Table 2 below. In Table 2 below, the weight is expressed as % based on the weight of the reinforcing bar (Comparative Example 1).

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 weight(%) 26 23 23 100 33 Tensile strength (Mpa) 900 932 952 550 790 Modulus of elasticity (Gpa) 55 52 38 200 94 Adhesion Strength ((Mpa) 30 32 29 40 38

As shown in Table 2, it was confirmed that the fiber-reinforced plastic reinforcing material prepared according to the examples of the present invention exhibited lower weight, improved tensile strength, elastic modulus, and adhesive strength compared to the reinforcing material of the comparative example.

[Experimental Example 2: Thermal Expansion Coefficient Measurement]

The coefficient of thermal expansion for each of the reinforcing materials prepared in the above Examples and Comparative Examples was measured according to ASTM D 696, and the results are shown in Table 3 below.

division Coefficient of thermal expansion (10 ^-5 /℃) Example 1 10.5 Example 2 8.3 Example 3 7.2 Comparative Example 1 14.0 Comparative Example 2 11.5

As shown in Table 3, in the case of the fiber-reinforced plastic reinforcement prepared according to the examples of the present invention, compared to the comparative example, it exhibits a low level of thermal expansion coefficient almost similar to that of concrete, so that it can have a low strain even during rapid temperature change. Confirmed.

[Experimental Example 3: Measurement of water resistance and chemical resistance]

Water resistance and chemical resistance of each of the reinforcing materials prepared in Examples and Comparative Examples were measured. In the measurement method, each prepared reinforcing material was immersed in salt water having a salt concentration of 35‰ and a sulfuric acid solution having a concentration of 2% for 1 hour every day, and whether the surface of the reinforcing material was damaged was checked for 60 days on a daily basis. The confirmation results are shown in Table 4 below.

item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Brine (35‰) 51 58 - 12 32 Sulfuric acid solution (2%) 29 38 52 5 21

As shown in Table 4, it was confirmed that the fiber-reinforced plastic reinforcing material according to the embodiment of the present invention showed higher water resistance and chemical resistance than the comparative example.

In this specification, only a few examples of various embodiments performed by the present inventors are described, but the technical spirit of the present invention is not limited or limited thereto, and can be modified and implemented in various ways by those skilled in the art, of course.

Claims (3)

preparing carbon fibers;
preparing a synthetic resin composition by mixing an unsaturated polyester resin, 4,4'-methylenebis-(2,6-diethylaniline), magnesium chloride, and yttria-stabilized zirconia;
impregnating the carbon fibers into the synthetic resin composition;
Forming a fiber-reinforced plastic reinforcing material by curing the carbon fiber-impregnated synthetic resin composition at a temperature range of 120° C. to 240° C.;
Spray coating and drying a mortar composition containing 45% by weight of marble powder, 20% by weight of Portland cement, 15% by weight of ultra-fast cement, 10% by weight of stone powder, and 10% by weight of aggregate on the fiber-reinforced plastic reinforcing material twice. step; and
Coating and drying a synthetic resin composite composition containing a polyurethane resin and Fe ₂ O ₃ on the coated fiber-reinforced plastic reinforcing material;
As a method for manufacturing a fiber-reinforced plastic reinforcing material comprising a,
The carbon fiber is characterized in that it is broken into a plurality of strands having a length of 1 to 50 mm and spread without a certain direction (Non-Axial Type),
Method for manufacturing fiber-reinforced plastic reinforcement. delete delete

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