KR101411259B1 - High-efficient and uniformly-heating system for bridge foundations using microwave, and construction method of bridge foundations using the same - Google Patents

Abstract

The present invention relates to a high efficiency and uniformly heating system for bridge foundation construction using a microwave, and a construction method of a bridge foundation using the same, and more specifically, to a heating system for bridge foundation construction, and a construction method of a bridge foundation using the same which is capable of reducing the construction period of a bridge foundation during the time when an outdoor temperature is low by reducing the initial hydration time of the concrete placed inside the mold by heating a mold by using a heating system heated by a microwave when the bridge foundation such as a pier, an abutment, etc. is constructed. The present invention has an effect of reducing the entire construction period by reducing the curing period by reducing the initial hydration time of the concrete when the bridge foundation is constructed by using the heating system using the microwave; warm curing concrete without using a heater, a fan heater, etc. in a warm curing process; and solving the problem of unequally heating, and possibility of crack generation due to the unequally heating.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-efficiency uniform heating system for a bridge foundation using a microwave, and a bridge construction method using the microwave,

The present invention relates to a high-efficiency uniform heating system for bridge foundation construction using a microwave, and more particularly to a high-efficiency uniform heating system using a microwave, , It is possible to shorten the initial hydration time of the concrete placed inside the formwork by heating the formwork, and thus it is possible to remarkably shorten the construction time period of the bridge in a low temperature environment such as the winter season and the cold weather area. System and a method of constructing a bridge foundation using the same.

A form refers to a temporary structure used during the process of manufacturing a concrete structure until the concrete is cured. Since it is a temporary structure, it is common to separate and reuse concrete after curing of concrete is completed. Concrete structures can be mass-produced at the factory or at the construction site, depending on their type and needs. Whether the mass production of the concrete or the production of the site is necessary, the formwork is necessary to accurately determine the shape and dimensions of the concrete structure.

Generally, a method for manufacturing a concrete structure using a conventional mold is to form a mold according to the shape of a concrete structure to be manufactured, to insert a reinforcing assembly into the mold, and then to pour concrete after curing the concrete.

Curing time is the most important factor in the construction period of the concrete structure using this form. That is, if the curing time is long, the construction period becomes longer, which causes the construction cost to increase. In particular, when the outside temperature is low, such as in the winter or in the cold region, the curing time is longer and the construction period becomes longer. As a result, the total construction cost increases and the delivery time is not satisfied. Furthermore, in the winter season, there is a problem in securing the quality of the concrete due to the delay of hydration reaction, so that it is not necessary to use a separate additive or perform the concrete pouring itself.

When manufacturing high-rise buildings such as bridges and buildings, they use the form of a Euro form, a slip form or a climbing form that cures concrete structures from below. In this case, Curing takes a very long time, so there is a problem that the entire construction period is lengthened. In particular, when the outside temperature is low, such as during the winter season or the cold season, this problem is more serious. In the past, in order to shorten the construction period, the construction method in which the heating wire is embedded in the mold to raise the temperature, I have been using the method. However, since the method for raising the temperature by using the heating wire needs to install the heating wire in the formwork, complicated electric work is additionally required. Also, since the electric power must be supplied continuously to the heating wire, a great amount of electricity is consumed. In addition, there is a problem in that a large amount of oil, gas, and electricity are consumed to heat the mold surface by the hot air. Therefore, there is a problem that the construction of the bridge foundation structure such as the bridge is stopped at the winter season due to such a problem.

For example, Korean Patent Registration No. 10-0748636 discloses a method for constructing a coiling portion integrally on top of a pier using a panel form member and a concrete pier provided with such a coping portion.

Korean Patent Laid-Open Publication No. 2003-0052872 also proposes a steel formwork for a pier foundation used in pouring a pier when installing a pier installed on a pile of a bridge site, and a steel material housing using the same.

Korean Patent Registration No. 10-0625782 proposes a method of constructing a reinforced concrete bridge pier structure by using a precast concrete segment manufactured in the form of a segment of a predetermined height as a mold substitute, and a pier structure thereof.

Also, Korean Patent Registration No. 10-0969992 discloses a pier die system capable of adjusting the tilt angle and height of the pier corresponding to the pier coping portions of various sizes and shapes.

Japanese Laid-Open Patent Publication No. 2006-00325292 discloses a method for constructing a building mold, which can be easily and inexpensively constructed using a plurality of formwork heat-insulating panels and a connecting bar having a length longer than the width of the heat- And the like.

However, the above-described prior arts are different from the object of the present invention proposed by the present inventors and the method for implementing the same in order to perform concrete construction when the outdoor air temperature such as the winter season is low.

In the existing method, the use of the existing method was limited, and even if the construction was carried out, there was a problem that the construction work of the foundation of the winter bridge was difficult due to safety problems, environmental problems, and excessive cost.

In order to solve the problems of the prior art, the present applicant has proposed a new construction method capable of shortening the construction period of the bridge foundation due to concrete curing by raising the temperature of the formwork by microwave without using a huge amount of electricity, oil, Method. (Korean Patent Application No. 10-2011-0130016, Patent Registration No. 10-1271397) When the above patented technology is used, the heating efficiency and the effect of promoting concrete curing by this effect are excellent, so that the construction of the base of the winter bridge can be effectively carried out. However, It is not enough to uniformly generate heat as a whole.

The present invention has been developed in order to solve the problems found in the existing technology proposed by the present applicant as described above. The first problem to be solved by the present invention is to provide a partition panel for a bridge foundation, It is possible to remarkably shorten the construction period by promoting the curing of the concrete by applying the heating system which is generated by the microwave, and at the same time, it is possible to achieve the uniform heating of the entire concrete bridge due to excellent heat generation efficiency and heat transfer efficiency And to provide a new environmentally friendly high efficiency heating system capable of improving physical properties such as strength.

A second problem to be solved by the present invention is to provide a new concept of bridge foundation curing construction method capable of accelerating and curing a high quality concrete bridge foundation using the new environmentally friendly high efficiency heating system according to the present invention.

In order to achieve the first object of the present invention,

A heat generating die attached to an outer panel of a partition provided on a bridge foundation construction mold and generating microwave by power supply,

A microwave generator for generating microwaves;

A waveguide connected at one end to the microwave generator and having a pipe shape for receiving a microwave generated from the microwave generator and transmitting the received microwave to the reflector;

A reflector having a sealed inner space for diffusing the microwave transmitted from the waveguide and sharing the inner space with the waveguide;

A distribution plate provided on the opposite side with respect to the waveguide and the sealed inner space and having a distribution hole for passing a microwave that is irregularly reflected by the reflection portion; A heating element which is provided on the opposite side of the reflection part and is in close contact with the distribution plate and absorbs microwaves passing through the distribution hole to generate heat;

And a cavity cover which is connected to the upper ends of the side plates and forms a closed reflective part together with the side plates, A cavity for transferring heat generated from the heating element to the outside; And

A temperature controller for controlling a heat generation temperature of the heating element;

And,

Wherein the heating element is a ceramic composition comprising a rapid cooling steel making slag having a particle size of 5.0 mm or less and a sphericity of 0.5 or more and silicon carbide particles having a particle size of 5.0 mm or less at a weight ratio of 100: 0.1 to 100, Provides a heating system.

In order to achieve the first object of the present invention,

(a) attaching a reinforcing bar for a bridge foundation, installing a mold, and attaching a heating system for bridge foundation construction using the microwave according to the present invention to a partition outer panel of the installed mold;

(b) casting concrete into the installed mold;

(c) supplying power to the heating system for bridge foundation construction using the microwave of (a) to generate heat;

(d) curing the poured concrete; And

(e) separating the heating system for the bridge foundation installation using the installed microwave

The method comprising the steps of:

The advantages of the high efficiency uniform heating system for bridge foundation construction using microwave and the basic construction method using the microwave according to the present invention will be described as follows.

1. It does not require complicated electric wiring work like a separate heating line work because it uses a module type which is generated by a microwave or a heating system which is integrated with a form panel and is attached to a partition of a conventional bridge basic construction form in a detachable or non-detachable manner. Also, after the completion of the construction, the disassembly operation is completed only by separating the heat generation system from the partition, so that there is no difficulty in disassembling the formwork, so the work is simplified, the workability is excellent, and the disassembly and reuse are easy.

2. The high-efficiency uniform heating system for bridge foundation construction using a microwave according to the present invention is designed so that even if electricity is supplied for only a few minutes to several tens of minutes, it reaches a desired temperature in a short time, Therefore, the energy consumption can be significantly reduced compared to the conventional heating line method, so that the energy efficiency can be improved.

3. The high-efficiency uniform heating system for bridge foundation construction using the microwave according to the present invention can be easily changed in design according to the partition form of the formwork, so that it can be freely manufactured in any form that the existing formwork work such as indoor or outdoor Can be utilized.

4. The high-efficiency uniform heating system for the bridge foundation construction using the microwave according to the present invention can be applied regardless of the external temperature, so that the construction period is shortened when the outdoor temperature is low, such as in the winter season or the winter season where the concrete curing time is long It has a great effect.

5. According to the high efficiency uniform heating system for bridge foundation construction using the microwave according to the present invention and the bridge foundation construction method using the same, there is no need to consume fuel such as oil or gas without causing safety problems and environmental problems, Cost can be reduced, and economical construction is possible.

6. In addition, a heating element that generates heat by microwaves is used in combination with materials having excellent heat generation efficiency, that is, energy efficiency, and materials having energy transfer efficiency, that is, excellent energy release rate, at an optimum ratio. The heat uniformity is remarkably improved as compared with the conventional materials.

7. In addition, since the internal structure of the heat-generating die is designed so that the microwave can be efficiently distributed as a whole in order to prevent the microwaves from being irradiated only locally, the uniform heating effect can be further increased in addition to the material design.

8. Therefore, it is possible to obtain high-quality construction because it is possible to obtain homogeneous concrete properties at the time of concrete bridge foundation construction by solving the problem of occurrence of crack due to the existing local overheating and the problem of unevenness of physical properties such as compressive strength.

1 is a plan view showing an example of a heat generation system for a bridge foundation construction using a microwave according to an embodiment of the present invention.
2 is a side cross-sectional view showing an example of a heating system for a bridge foundation construction using a microwave according to an embodiment of the present invention.
FIGS. 3A to 3D are plan views showing several examples of distribution plates applied to a heating system for bridge foundation construction using a microwave according to an embodiment of the present invention. FIG.
FIG. 4 shows an external shape of a heating element used in a heating system for a bridge foundation construction using a microwave according to an embodiment of the present invention.
5 is a graph showing internal energy and emission energy evaluation results of the rapid cooling steel slag, the hydrocarbon, and the mixture thereof according to an embodiment of the present invention.
FIG. 6 is a flowchart showing a basic construction method of a bridge using a microwave-based heating system for a bridge foundation construction according to an embodiment of the present invention.

In the present invention, the meaning of " ideal " means that the value is not less than the corresponding value, and generally has an upper limit that is reasonably understandable in the field to which the present technology belongs. Means that the invention has a lower limit of common sense and reasonably understandable in the field to which the present invention belongs, it should be understood as an expression for expressing the invention in a simple and clear manner.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

FIG. 2 is a plan view showing an example of a heating system for bridge foundation construction using a microwave according to an embodiment of the present invention, and FIG. 3 is a side sectional view thereof.

As shown in FIGS. 2 and 3, the heating system 20 for a bridge foundation construction using a microwave according to the present invention includes:

A microwave generator 21 for generating a microwave;

A waveguide 22 connected at one end to the microwave generator 21 and having a pipe shape for receiving microwave generated from the microwave generator and transmitting the received microwave to the reflector;

A reflector 24 having a sealed inner space 23 for diffusing the microwave transmitted from the waveguide and sharing the inner space with the waveguide;

A distribution plate (25) provided on the opposite side of the waveguide and the sealed inner space and having a distribution hole (26) for passing a microwave that is irregularly reflected by the reflection portion;

A heating element (27) provided on the opposite side of the reflection part to closely contact the distribution plate and absorbing microwaves passing through the distribution hole to generate heat;

A bottom plate (28-1) provided outside the heating element in close contact with a heating element, a side plate (28-2) connected to both side ends integrally with the bottom plate, and an upper A cavity 28 composed of a cavity cover 28-3 forming a closed reflective part 24 and transferring heat generated from the heating element to the outside; And

A temperature controller 33 for controlling the temperature of the heat generated by the heating element,

And,

The heating element is a ceramic composition comprising a rapid cooling steel making slag having a particle size of 5.0 mm or less, a sphericity of 0.5 or more, and silicon carbide particles having a particle size of 5.0 mm or less at a weight ratio of 100: 0.1 to 100.

In the present invention, the microwave generator or other magnetron is connected to a power source by a high voltage transformer 29, and an air cooling type cooling device (for example, a cooling fan 30) for cooling the heat generated in the microwave generator, It is preferable that an apparatus is provided.

In addition, it is preferable that a protective cover 31 for protecting the internal devices such as the microwave generator, the high voltage transformer, and the cooling device is fixed to the cavity cover 28-3.

The cavity 28 is provided with a temperature sensor 32 for detecting the temperature of the cavity. The temperature sensor is connected to the temperature controller 33 to control operation of the microwave generator and the cooling device according to the temperature of the cavity. .

In addition, it is preferable that a case 34 for protecting internal devices is provided outside the microwave generator, the waveguide, and the cavity. The case 34 may be made of a plastic material to reduce weight and may be manufactured by injection molding or extrusion molding.

Further, it is preferable that the heat insulating material 35 is attached to the cavity cover 28-3 in order to prevent the heat generated inside from being diverted to the opposite side of the heating object. Glass wool, gypsum, heat-resistant plastic, heat-resistant ceramic, heat-resistant paper or stone powder can be used as the material of the heat-insulating material.

Wherein the heating element comprises a metal oxide including an iron oxide compound and is heated by a microwave of 300 MHz to 300 GHz. Specifically, the heating element uses a heating element composition that generates heat by using the microwave described above. Specifically, the heating element has a quenching steel slag having a particle size of 5.0 mm or less, a sphericity of 0.5 or more, and silicon carbide particles having a particle size of 5.0 mm or less, Or a cured product obtained by mixing cement in a weight ratio of 0.1 to 50 to 100 parts by weight of the ceramic composition and curing the mixture by hydration with an appropriate amount of water is used. In this case, when the ceramic composition is used as it is, it is preferable to adhere to the bottom plate using a heat-resistant bond. For example, the ceramic composition may be mixed with the heat-resistant bond and attached to the bottom plate.

The heating system for the bridge foundation construction using the microwave can rapidly heat the surface of the bridge foundation concrete through the heating element only by generating microwaves by applying power to the micro generator.

The microwave generator, the waveguide, and the heating element are preferably modularized in the form of being mounted inside the cavity and installed in the heating object, but the present invention is not limited thereto and various design modifications are possible.

In particular, it is preferable that the waveguide has a tubular shape in which one end thereof is directly connected to the microwave generator and the other end is connected to a reflector having a closed space therein.

The microwave generator (magnetron) is connected to the high voltage transformer and the high voltage transformer is connected to the external power source. The high voltage transformer transforms a commercial AC voltage input from the outside into a high voltage (for example, about 2 kilovolts [kV]) suitable for generating a high frequency and applies it to the magnetron. The magnetron generates high frequency oscillation by a high voltage applied from a high voltage transformer Thereby generating microwaves.

It is preferable to use the 2,450 MHz band in order to utilize the advantage of the microwave frequency, such as Industrial, Scientific and Medical (ISM) frequency. However, it is not limited to this, Microwave having a frequency in the range of 300 GHz can be used in various ways.

A cooling device (e.g., a cooling fan) is installed around the magnetron to cool the high temperature generated by the magnetron when the magnetron is driven. A cooling device is connected to the fan motor. A voltage (commercial AC voltage) When the motor is applied to the motor, the fan motor is operated, and the fan of the cooling device is driven by the fan motor to blow the external cool air to the magnetron, thereby cooling the high temperature generated in the magnetron.

The microwave generator is fixed to the side surface of one end of the waveguide by a fixing bracket and is connected to the side surface of one end of the waveguide by a coupling tube protruding from the back surface of the microwave generator, Can be delivered to the department.

These microwave generators are consumables and must be replaced when they reach their end of life. In the heating die according to the present invention, the microwave generator can be easily replaced as if replacing a bulb. Therefore, the microwave generator according to the present invention can be used permanently only when the microwave generator is replaced periodically or when a fault occurs.

In the present invention, the heating element has heat resistance and has a heat resistant plate structure having a long length and a ceramic material (see FIG. 4). When a microwave is irradiated on a ceramic material plate having a high dielectric loss factor, Heat is generated by dipole rotation.

Meanwhile, as described above, since the microwave generator is installed on the side surface of one end of the waveguide to supply microwaves, a portion directly connected to the waveguide in the reflection portion receives a lot of microwaves and receives less influence of microwaves. In order to smoothly diffuse the microwave, a distribution plate is disposed in the middle of the distribution plate so that the microwave is substantially reflected in the distribution plate, so that a certain degree of microwave can be absorbed .

Some forms of the distribution plate having the distribution holes in the present invention are as shown in Figs. 3A to 3D.

As shown in FIGS. 3A to 3D, it is preferable that the distribution plate is formed symmetrically with respect to the waveguide rather than having a distribution hole formed just in front of the waveguide. However, they are not necessarily provided symmetrically but may be provided asymmetrically. In this case, the shape of the dispensing hole may be variously designed such as a circle, an ellipse, and a square.

Further, since the density of the microwave is decreased as the distance from the waveguide decreases, it is preferable that the size of the distribution hole increases as the distance from the waveguide increases, so that the heat is further generated farther from the waveguide, Do.

In addition, in the present invention, since the waveguide can be biased not only at the center of the distribution plate but also at one point, it is preferable that the distribution hole is designed to be optimally designed to absorb the microwave even at a point away from the waveguide.

In the present invention, the material used as the distribution plate is preferably a material that reflects without absorbing microwaves, and examples thereof include steel, aluminum, or copper.

Further, in the present invention, it is preferable that the distribution plate has a smooth plate shape or a plate shape which is uneven on the surface.

Hereinafter, the heating element 27 used in the heating system for bridge foundation construction using the microwave used in the present invention will be described in detail.

4 shows the external shape of the heating body 27 according to the embodiment of the present invention. 4, the heating element according to the present invention is a ceramic composition comprising a rapid cooling steel making slag having a particle size of 5.0 mm or less, a sphericity of 0.5 or more, and silicon carbide particles having a particle size of 5.0 mm or less at a weight ratio of 100: 0.1 to 100 desirable. In the present invention, the particle size of the rapid-cooling steelmaking slag is more preferably 3.0 mm or less, and still more preferably 1.0 mm or less. In addition, in the present invention, the silicon carbide particles preferably have a particle size of 3.0 mm or less, more preferably 1.0 mm or less. The mixing weight ratio of the rapid-cooling steelmaking slag to the silicon carbide particles is preferably 100: 0.1 to 50, more preferably 100: 0.5 to 20. The heating element may be used as the ceramic composition itself. However, the curing composition 10 may be obtained by mixing 100 parts by weight of the ceramic composition with cement in a weight ratio of 0.1 to 50, adding an appropriate amount of water and kneading, Is more preferably used. In this case, since the content of the ceramic composition is high and a small amount of cement is contained, it shows a dark gray or light black color from the outside. Fig. 4 shows the outer shape of the cured product. The cured product may be used as it is in the shape of Fig. 4, or may be used in a state where the surface thereof is processed flat. When the ceramic composition is used as it is, it is preferable to mix it with a heat-resistant bond such as a ceramic bond and attach it to the bottom plate.

Conventionally, the slag discharged from a steel mill is treated by discharging the slag into a slag pot disposed in a lower portion of a converter or an electric furnace and then discharging the slag to a treatment plant. In the conventional treatment method, a large amount of water is sprayed on the discharged slag to cool the slag The iron content in the slag after solidification and subsequent crushing process is selected through a magnetic separator to be used as a steel source, and the remaining slag is mostly used as an aggregate such as landfill or road pavement because it has no special purpose. However, when the waste slag is simply buried in the landfill, the cost of the landfill is inconvenient and the burden of the landfill is considerably burdensome if the amount of the landfill is large. Therefore, there is an environmental problem, .

The steel slag cooled by the cooling (slow cooling) is called a slow cooling steel slag and contains a large amount of free limite (free CaO) ₂ ). Since the calcium hydroxide formed is bulky and prone to be differentiated from free lime, when used as a roadbed material, there is a problem that the road is flooded and the differentiated calcium hydroxide causes pollution of air and water quality. In addition, because calcium hydroxide is alkaline, it causes soil contamination and its use as road pavement aggregate is also very limited.

Rapid cooling steel slag was introduced to solve the problem of the slow cooling steel slag. Rapid cooling steel slag can be produced by a method of dropping a hot molten slag and spraying a high speed air stream to shake a hot molten slag to rapidly cool it by a high speed air stream and to make it into a fine powder form. When this method is used, slag in the form of fine powder is produced instead of bulk slag, so there is no need of separate crushing process and the effect of reducing the amount of free limes. However, since conventional quench steelmaking slag has focused on reducing the amount of free limes and using it as a construction aggregate, the development of new capacity has been sluggish.

The present invention has developed a new application of such a rapid steelmaking slag, and the rapid cooling steel slag absorbs microwaves and finds a property of generating heat, and uses this as a heat generating material.

The rapid-cooling steelmaking slag used in the present invention is not produced by using conventional quenching steelmaking slag which is conventionally used but is manufactured in a refined form by using a special sorting and refining method.

Hereinafter, such a selection / purification method will be described in more detail.

First, an example of a method of manufacturing the rapid cooling steelmaking slag according to the present invention is as follows. That is, the rapid cooling steelmaking slag having a particle diameter of 5.0 mm or less is selected through a sieving process in a first step, and a magnetic separator having a magnetic force of 500 gauss or more, preferably 700 to 5,000 gauss is used as a second step Only the particles having the microwave absorption efficiency required in the present invention are selected, and only spherical particles having a spherical modulus of 0.5 or more are selected through a spherical separator. At this time, the above-described seeding process, spherical sorting process, and magnetic force selecting process may be performed in sequence or simultaneously, all of which are included in the scope of the present invention. In the present invention, the rapid-cooling steelmaking slag obtained through such a special sorting and refining operation is simply referred to as " MIP (Microwave-irradiated pyrogen) ".

In the present invention, the particle size of the quench-hardened steelmaking slag is preferably 5.0 mm or less and the spherical ratio is required to be 0.5 or more. If the particle size exceeds 5.0 mm, if the particle size is excessively large, the total cross-sectional area is not large, and heat efficiency and heat transfer efficiency are deteriorated. The sphericity ratio is, in other words, the shape factor, which means the ratio of the smallest diameter to the longest side diameter of the particles. If the sphericity of the rapid cooling steel slag having a sphericity ratio of less than 0.5 results in a distorted shape, In this case, the spark may occur. Since the energy is concentrated only at the pointed portion or the angled portion and energy loss occurs, the efficiency of heat generation in the entire particle is lowered. Therefore, the spherical ratio should be selected to be 0.5 or more do. This rapid steelmaking slag has the characteristics of a semi-insulator between the conductor and the non-conductor, so that absorption heating and induction heating are performed, and the internal microwave is transferred according to the charging state. That is, when the microwave is applied to the continuous spherical rapid cooling steel making slag, the microwave is transferred along the rapid cooling steel slag due to the surface effect, and absorption heating and induction heating are performed in the adjacent rapid cooling steel slag as before.

The present inventors have proposed a technique of utilizing a rapid-cooling steelmaking slag composition as a heating body to be heated by a microwave through the above-mentioned patent (Korean Patent Application No. 10-2011-0032313).

However, the rapid-cooling steelmaking slag composition described in the above patent has a very high energy generated by the specific heat and the microwave, but it is not so fast in terms of the transfer speed for transferring it to the periphery, i.e., the energy release rate, And it is found that there is a problem that it takes a lot of time and the local fever progresses. As a result of repeated research efforts to overcome these problems, it has been found that a combination of quenching steel slag and silicon carbide (SiC) can be solved. That is, in the case of silicon carbide, which has been known as a material capable of being heated by microwaves, the energy generated by the specific heat and microwave is lower than that of the rapid-cooling steel slag as shown in Table 1 below, The rate of transfer is much higher than that of rapid cooling steelmaking slag. Accordingly, the present inventors have found that when mixed with silicon carbide having a high energy transfer rate, problems of low energy transfer and uneven heat generation, which were problems in using the conventional quenching steel slag alone, can be solved.

Rapid cooling steelmaking slag (MIP) Silicon carbide (SiC) specific heat 0.1807 Cal / g 占 폚 0.1624 Cal / g 占 폚 Energy release rate 0.343 W / m · K 170 W / m · K

Table 2 shows the results of measurement of heat efficiency by microwave using silicon carbide, MIP and water. Using Equation 1, the thermal energy used to raise the temperature is expressed as the used power, and the energy efficiency is calculated based on the ratio of the used power according to the input power using Equation 2.

unit sign Silicon carbide (SiC) MIP water Mass (g) M 200 200 200 Specific heat (Cal / g · ° C) Cp 0.1624 0.1807 One Temperature difference (℃) ΔT 79.1 152.8 22.5 Time (seconds) t 60 60 60 Power (W) P 179.8 386.5 315 Incoming power (W) Pin 700 700 700 Energy efficiency η 0.26 0.55 0.45

(수식1)

(수식2)

(Equation 1)

(Equation 2)

As shown in the above Table 2, it can be seen that the efficiency of heat generated by the microwave for the same input power is more than twice that of the hydrocarbon.

The results of internal energy and emission energy of MIP, silicon carbide, and mixtures thereof obtained through the above experiment are shown in FIG. As shown in FIG. 5, the MIP heating element has a high energy generation rate, but the transfer speed is low. Conversely, the silicon carbide has a relatively small energy generation, but has a high speed of transferring the energy. You can get both effects of delivery. (This experiment was conducted by Korea Polymer Research Institute, Korea). Specific heat analysis was performed using Perkin-Elmer DSC 4000 by KS M 3049 method. Thermal conductivity was measured by Mathis TC -30. In the case of the mixture of the present invention, MIP: SiC was mixed in a weight ratio of 100: 0.5.

As can be seen from the experimental results shown in FIG. 5, in the case of MIP alone, the internal energy is raised by microwave irradiation, but the emission energy is low. In the case of silicon carbide alone, the internal energy raised by microwave irradiation is not limited to MIP, Is very high.

Therefore, when the MIP and silicon carbide are mixed with each other using such a characteristic, the internal energy is relatively high and the energy release property is maintained high. Thus, the problem of using the existing MIP alone can be solved.

In the present invention, such MIP, that is, a rapid cooling steel making slag having a particle size of 5.0 mm or less and a sphericity of 0.5 or more is mixed with silicon carbide particles having a particle size of 5.0 mm or less at an optimum ratio. Since silicon carbide is about 30 to 50 times higher in price than MIP in terms of unit cost, it is not economically advantageous to use a large amount of silicon carbide. Therefore, silicon carbide should be used in an optimum ratio. In the present invention, By weight, and more preferably 100: 0.1 to 50 parts by weight. If the silicon carbide is used in an amount of less than 0.1 part by weight based on 100 parts by weight of MIP, the energy transfer efficiency is lowered. Therefore, it is difficult to solve the problem when the conventional MIP is used alone. If the silicon carbide is used excessively in excess of 100 parts by weight, It is undesirable because the price may fall and the unit price may rise too much and the economic effect may decrease.

In the present invention, the ceramic composition containing the rapid-cooling steelmaking slag (MIP) having a particle size of 5.0 mm or less and a sphericity of 0.5 or more and silicon carbide (SiC) particles having a particle size of 5.0 mm or less in an optimum ratio may be used as it is, Is used as a cured form by mixing cement and water. The reason for using such a cured form is that when the uncured particle (particle) form is used, the handling property is not good and there is a fear that the cement is caught in one side. In the case of cured cement, the latent heat is retained for a long time This is because there is also an effect. In the present invention, the cement mixed with the ceramic composition, for example, Portland cement, is preferably mixed with 100 parts by weight of the ceramic composition in a weight ratio of 0.1 to 50, and the mixture is hydrated by adding an appropriate amount of water, Whereby a cured product is obtained. In this case, the thickness of the cured product may vary depending on the application, and it is preferably 1 to 100 mm for general use. On the other hand, in the production of a cured product, it is also possible to produce a cured product by mixing it with a heat resistant board such as a ceramic bond without using cement.

In the present invention, the ceramic composition may further include a metal oxide, which is conventionally known to absorb microwaves. The content of the metal oxide is preferably in the range of 0.1 to 100 parts by weight, more preferably 0.5 to 50 parts by weight to be. The size of the ceramic composition is preferably 5.0 mm or less, more preferably 3.0 mm or less, and still more preferably 1.0 mm or less. Examples of such metal oxides are iron oxides, and specific examples thereof include Fe ₂ O ₃ , Fe ₃ O ₄ and FeO. Examples of other metal oxides include Al ₂ O ₃ , CaO, SiO ₂ , TiO ₂ , MgO, and the like.

In the present invention, a heating element is manufactured by using a heating element that generates heat by the microwave, and the structure of the heating element is as described above.

The heating system using the microwave according to the present invention can be easily installed by simply attaching the heating system to the outer panels of the partitions of the bridge foundation work structure by detachably or non-detachably installing the power supply, As the temperature rises quickly and the temperature rises slowly, there is an advantage of not consuming excessive power to maintain the set temperature. In addition, the quality of the cured concrete such as strength and durability can satisfy the required quality and above, and uniform quality can be ensured due to uniform heat generation.

In particular, when the outdoor temperature is low, such as during the winter or the cold, the concrete can not be cured due to the natural hydration of the concrete. Thus, the concrete pouring process in the winter is very limited. However, when the heating mold is heated by the microwave according to the present invention, Is supplied to the concrete to induce a temperature increase in the initial stage and then natural hydration proceeds, thereby making it possible to cure the concrete which is not significantly different from the construction in the summer.

Therefore, it can result in accelerating curing of concrete when it is used in a period of long period of concrete curing due to a low temperature such as winter, early spring, and late autumn, or in an extreme region such as Siberia and Mongolia.

In addition, after completion of the construction of the bridge foundation, the heating system needs only to be separated from the partition of the formwork, so that complicated work for separation and disassembly is not necessary, and the heating system can be easily reused.

6 is a flowchart showing a construction method of a bridge foundation according to an embodiment of the present invention.

As shown in Figure 6, a method of constructing a bridge foundation according to the present invention

(a) a step (S100) of attaching a heating system for bridge foundation construction using the microwave according to the present invention to an outer panel of a partition of the installed formwork after the reinforcement for a bridge foundation is installed and a form is installed;

(b) pouring concrete into the installed mold (S200);

(c) a step (S300) of supplying power to the heat generation system for bridge foundation work using the microwave to generate heat;

(d) curing the poured concrete (S400); And

(e) separating the heating system for the bridge foundation construction using the installed microwave (S500)

And a control unit.

In the above description, it is described that the step of attaching the heating system using the microwave according to the present invention to the outer panel of the partition of the mold, which is the step (b), precedes the step of pouring the concrete in the form of the step (c) , The order of steps (b) and (c) may be reversed, so that the order should not be construed as limiting the scope of the present invention.

Generally, in the case of a form, a partition is installed outside the form to prevent the form from being turned or deformed. In the present invention, a device (system) capable of generating heat is installed in the partition to rapidly form a concrete bridge foundation Is a feature of the invention. In the conventional bridge foundation construction method, concrete is placed in the mold, and the concrete surface is heated by heating the concrete surface by blowing hot air from the outside or by raising the temperature by natural hydration heat, Were used. In the case of the conventional method, when the outside air temperature is low, hydration does not occur well. Therefore, it takes a long time to cure, and when hot air is injected to promote this, various problems such as high fuel consumption and environmental problems are caused .

The present invention has been developed to solve the problems of the prior art,

In a method of constructing a bridge foundation according to the present invention, first, a reinforcement is installed at a point where a bridge foundation is to be constructed, and a formwork to support the bridge is installed. Next, a heating system for bridge foundation construction using the microwave according to the present invention is attached to an outer panel of each partition of the installed mold.

In order to facilitate curing by attaching a heating system for bridge foundation construction using a microwave according to an embodiment of the present invention to a partition of a mold according to an embodiment of the present invention, So that the bridge foundation construction can be carried out.

Then, concrete is poured into the mold. Thereafter, power is supplied to the heating system using the microwave attached to the mold partitions to heat the surface of the mold, thereby forcibly inducing the initial hydration of the poured concrete. Since hydration of concrete is difficult to proceed when the outside air is low as in winter, inducing initial hydration of concrete by forced heating promotes curing of concrete since natural hydration proceeds thereafter. Once the curing of the concrete is completed, the heating system using the installed microwave is separated and disassembled to complete the construction of the bridge foundation.

The high efficiency uniform heating system for the bridge foundation construction using the microwave according to the present invention and the bridge foundation construction method using the same have been described above. The high-efficiency uniform heating system for bridge foundation construction using microwave according to the present invention enables sufficient initial hydration even when the outdoor temperature is low, such as in winter, when the bridge foundation is used for early curing of concrete, Can be effectively achieved. Especially, it protects the concrete from the initial East Sea in the winter season, secures the required strength, accelerates the development of the strength by curing the concrete with rapid curing, and it is possible to shorten the length of the air and significantly reduce fuel consumption and power consumption Low-cost, and high-efficiency technology that can be reduced in cost, and is a low-carbon, eco-friendly technology that can be secured with no toxic gas such as the conventional method. Particularly, the possibility of uneven heating, which was a problem in the technique disclosed by the present inventors, and the possibility of cracking due to the uneven heating can be solved by the present technology.

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, something to do.

10: MIP hardener
20: Heat generation system for bridging foundation heat generated by microwave
21: Microwave generator 22: Waveguide
23: inner space 24:
25: Distribution board 26: Distribution board
27: heating element 28: cavity
28-1: bottom plate 28-2: side plate
28-3: Cavity cover 29: High voltage transformer
30: cooling fan 31: protective cover
32: temperature sensor 33: temperature controller
34: Case 35: Insulation
36: Capacitor 37: Capacitor holder

Claims (16)

A heating system installed on an outer panel of a partition provided on a bridge foundation construction mold and generating microwave by power supply,
A microwave generator for generating microwaves;
A waveguide connected at one end to the microwave generator and having a pipe shape for receiving a microwave generated from the microwave generator and transmitting the received microwave to the reflector;
A reflector having a sealed inner space for diffusing the microwave transmitted from the waveguide and sharing the inner space with the waveguide;
A distribution plate provided on the opposite side with respect to the waveguide and the sealed inner space and having a distribution hole for passing a microwave that is irregularly reflected by the reflection portion; A heating element which is provided on the opposite side of the reflection part and is in close contact with the distribution plate and absorbs microwaves passing through the distribution hole to generate heat;
And a cavity cover which is connected to the upper ends of the side plates and forms a closed reflective part together with the side plates, A cavity for transferring heat generated from the heating element to the outside; And
A temperature controller for controlling a heat generation temperature of the heating element;
And,
Wherein the heating element is a ceramic composition comprising a rapid cooling steel making slag having a particle size of 5.0 mm or less and a sphericity of 0.5 or more and silicon carbide particles having a particle size of 5.0 mm or less at a weight ratio of 100: 0.1 to 100, Heating system.
The heating system for a bridge foundation construction using microwave according to claim 1, wherein the heating element is a cured body obtained by mixing 100 parts by weight of the ceramic composition with 0.1 to 50 parts by weight of the cement, and curing the mixture by hydration.
The heating system according to claim 1, wherein the heating element is attached to the bottom plate using a heat-resistant bond.
The heating system according to claim 1, wherein the microwave generator is connected to a power source by a high voltage transformer.
.
[5] The system of claim 4, wherein a cooling device for cooling the heat generated by the microwave generator is provided in the vicinity of the microwave generator.
[6] The heating system for a bridge foundation construction using microwave according to claim 5, wherein a protective cover for protecting the microwave generator, the high voltage transformer, and the cooling device is fixed to the cavity cover.
The microwave-assisted bridge according to claim 1, wherein the cavity is provided with a temperature sensor for detecting the temperature of the cavity, and the temperature sensor is connected to the temperature controller to control the temperature of the microwave generator according to the temperature of the cavity. Heating system for basic construction.
The heating system for a bridge foundation construction using microwave according to claim 1, wherein a case for protecting internal devices is provided outside the microwave generator, the waveguide, and the cavity.
The heating system for a bridge foundation construction using microwave according to claim 1, wherein a heat insulating material is attached to the cavity cover so as to prevent heat generated from the inside of the cavity cover from dissipating toward the opposite side of the concrete to be heated.

[3] The heating system for a bridge foundation construction using microwave according to claim 1, wherein the distribution hole is not formed in a front portion of the wave guide, but is symmetrically or asymmetrically formed around the wave guide.

[3] The heating system for a bridge foundation construction system according to claim 1, wherein the distribution holes are arranged so as to become larger as they are away from the wave guide.
The heating system as claimed in claim 1, wherein the distribution hole is formed in a circular, elliptical or quadrangular shape.
The heating system according to claim 1, wherein the distribution plate is a steel material, an aluminum material, or a copper material.
The heating system according to claim 1, wherein the distribution plate is a plate-like or uneven plate-like shape.
[3] The heating system for a bridge foundation construction using microwave according to claim 1, wherein the ceramic composition further comprises 0.1 to 100 parts by weight of a metal oxide.
(a) attaching a heating system for bridge foundation installation using a microwave according to claim 1 to an outer panel of a partition of the installed mold after a reinforcement for a bridge foundation is installed and a form is installed;
(b) casting concrete into the installed mold;
(c) supplying power to the heating system for bridge foundation construction using the microwave of (a) to generate heat;
(d) curing the poured concrete; And
(e) separating the heating system for the bridge foundation installation using the installed microwave
Wherein the method comprises the steps of:

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