KR20130068514A

KR20130068514A - Method for manufacturing marine concrete structure using phase change material

Info

Publication number: KR20130068514A
Application number: KR1020110135746A
Authority: KR
Inventors: 손명수
Original assignee: 지에스건설 주식회사
Priority date: 2011-12-15
Filing date: 2011-12-15
Publication date: 2013-06-26

Abstract

Provided is a marine concrete structure and a method of manufacturing the same, which incorporates a changeable material into concrete and cures at high temperature to maximize watertightness, thereby enhancing durability of the marine concrete structure affected by the diffusion of salts through water. . The method for manufacturing marine concrete structures using phase change materials includes a) 38 to 42 parts by weight of paraffin wax having a phase change temperature of 60 to 90 ° C. and a nonionic surfactant based on poly oxyethylene strearyl ether. Preparing a phase change material for concrete comprising 8 to 12 parts by weight, 18 to 22 parts by weight of anionic surfactants based on sulfates or polycarbonates, and 28 to 32 parts by weight of water; b) incorporating the phase change material into the concrete; c) hot curing the concrete mixed with the phase change material; And d) dissolving paraffin wax of the phase change material in the internal pores of the concrete to coat the pores so as to impede the movement of moisture in the concrete to promote water tightness.

Description

Marine concrete structure using phase change material and its manufacturing method {METHOD FOR MANUFACTURING MARINE CONCRETE STRUCTURE USING PHASE CHANGE MATERIAL}

The present invention relates to a marine concrete structure, and more particularly, to a marine concrete structure using a phase change material (Phase Change Material) and a method of manufacturing the same to increase the durability of the marine concrete structure.

Recently, construction of reinforced concrete structures exposed to the marine environment such as long bridges connecting islands and land, islands and islands, tidal power plants using tidal tides, and high-rise structures around the coast have been increasing.

Reinforced concrete structures exposed to the marine environment have a penetration and diffusion of chloride into concrete over time.

At this time, the chloride penetrated into the concrete to corrode the steel to reduce the cross-sectional area, adhesion strength and stiffness of the reinforcing steel, causing the crack of the concrete and eventually reduce the durability life of the concrete.

In the marine environment, the chloride penetration into the concrete is largely due to the direct penetration from seawater or the adjuvant salt from the atmosphere adsorbed on the concrete surface.

In addition, in marine environments, concrete structures are located in water, splash zones, and atmospheric zones, and when concrete structures are located in water, chlorides penetrate directly from seawater. In the air section, it is penetrated by sea salt particles. In the case of splash zones, chloride is infiltrated directly from seawater by car and tidal penetration in combination with tidal salt.

In particular, the wet zone repeats dryness and wetness only due to the difference between tides, and in the case of winter, complex deterioration such as freeze-thawing occurs, resulting in a relatively low concrete durability.

Therefore, as a countermeasure against flame resistance of concrete structures in the marine environment, the unit quantity or water-binder ratio is lowered on the mixing side, and the concrete structure is water-tightized by using mixed materials such as fly ash, blast furnace slag powder, and silica fume, which are inorganic mixed materials. To inhibit the penetration of chloride ions or mixed with rust inhibitors.

In addition, the splash zone may be additionally applied with an organic coating material or an electric method.

However, lowering the water-bonding material cost and applying a small amount of unit increases the viscosity of the concrete, which causes difficulties in concrete production and quality control.

In addition, when a large amount of fly ash and blast furnace slag powder is used, the initial reactivity is lowered, leading to a decrease in initial strength of the concrete, and when silica fume is used, there is a problem in that the economic efficiency is lowered when concrete is produced.

In addition, when the rust inhibitors are used in combination, rust inhibitors are expensive and still have many problems in practicality.

In addition, when the organic coating material is applied, a phenomenon in which the organic coating material is peeled off with time may occur because the thermal expansion coefficients of the organic and the concrete are different. In the case of the electric system, there is a problem that additional processes are required, and construction costs are increased, as well as continuous maintenance is required.

On the other hand, as a related technology for solving the above problems, the Republic of Korea Patent No. 10-1071239 discloses the invention named "offshore concrete anticorrosive method using organic-inorganic hybrid nano-silica".

The marine concrete anticorrosive method using organic-inorganic hybrid nanosilica includes: a) 30 to 83.5 parts by weight of one kind of ordinary portland cement, 10 to 45 parts by weight of blast furnace slag powder, 5 to 20 parts by weight of fly ash and organic or inorganic Marine concrete manufacturing process for producing marine concrete using marine concrete cement composed of 0.5 to 5 parts by weight of hybrid nanosilica; b) a structure fabrication process of manufacturing concrete structures by pouring the prepared marine concrete; And c) a surface protectant applying process for applying a liquid surface protectant to the concrete structure.

According to the marine concrete anticorrosion method using organic-inorganic hybrid nanosilica according to the prior art, it is possible to densify the structure by filling the voids in the concrete, and to induce the electrochemical equilibrium state to suppress the penetration and diffusion of chloride ions. .

As described above, the marine concrete structure is affected by the diffusion movement of salt through water, and in the case of the marine concrete anticorrosive method using organic-inorganic hybrid nanosilica according to the prior art, blast furnace slag used as a mixed material Na fly ash has a low reactivity, the initial strength is delayed, and also due to the lack of calcium there is a problem that the degradation rate due to concrete neutralization is too fast.

1) Republic of Korea Patent No. 10-683131 (application date: November 14, 2005), the title of the invention: "Phase change material for concrete and its manufacturing method" 2) Republic of Korea Patent No. 10-1071239 (Application Date: April 13, 2009), the title of the invention: "Marine concrete anticorrosive method using organic-inorganic hybrid nano-silica" 3) Republic of Korea Patent No. 10-715517 (application date: February 28, 2007), the name of the invention: "Inflammation resistance enhancer composition for high durability concrete and concrete composition using the same" 4) Republic of Korea Patent No. 10-502278 (application date: December 27, 2002), the title of the invention: "organic-inorganic cross-linked composite polymer coating composition and method for producing a concrete surface finish coating" 5) Republic of Korea Patent No. 10-502698 No. (application date: December 21, 1999), the title of the invention: "Petroleum concrete composition for producing marine structures and environmentally friendly method"

The technical problem to be solved by the present invention for solving the above problems, marine concrete structure affected by the diffusion movement of salt through the moisture by maximizing the water tightness by curing the concrete mixed with the phase change material at high temperature It is to provide a marine concrete structure and a method of manufacturing the same using a phase change material that can improve the durability of the.

As a means for achieving the above technical problem, in the marine concrete structure manufacturing method according to the present invention, a) 38 to 42 parts by weight of paraffin wax of 60 to 90 ℃ phase change temperature, polyoxyethylene stearyl acid ether ( 8 to 12 parts by weight of a nonionic surfactant of poly oxyethylene strearyl ether), 18 to 22 parts by weight of anionic surfactant of sulfate or polycarbonate type, and 28 to 32 parts by weight of water Manufacturing step; b) incorporating the phase change material into concrete; c) hot curing the concrete mixed with the phase change material; And d) dissolving paraffin wax of the phase change material in internal pores of the concrete to coat the pores so as to impede the movement of moisture in the concrete to enhance water tightness.

Herein, the water absorption coefficient of the mortar for concrete, in which the phase change material is mixed and cured, is 0.03.

Here, the step a), a-1) mixing 38 to 42 parts by weight of paraffin wax and 8 to 12 parts by weight of a nonionic surfactant; a-2) heating the mixture of the paraffin wax and the nonionic surfactant above the melting point; a-3) stirring the mixture at 3000 rpm using a homomixer at high speed; a-4) adding 28 to 32 parts by weight of water and 18 to 22 parts by weight of anionic surfactant to the mixture; a-5) rapidly stirring the mixture to which the water and the anionic surfactant are added using a homomixer; a-6) quenching the emulsion at a temperature of 5 ° C. or lower so that the temperature of the emulsion is 20 ° C. or lower to firstly form a creamy phase change material; And a-7) adding 48 to 52 parts by weight of water and 8 to 12 parts by weight of a silicone- or fatty acid-based antifoaming agent to the first phase of the creamy phase change material, thereby changing to a final phase change material suitable for concrete. have.

Here, the step c) is characterized in that the high temperature curing at a temperature of 60 ~ 90 ℃.

According to the present invention, by incorporating a phase change material consisting of paraffin wax, nonionic surfactant, anionic surfactant and water into concrete and curing at high temperature to maximize watertightness, it is influenced by the diffusion movement of salt through water. The durability of the receiving marine concrete structure can be improved. That is, watertight concrete can be formed to ensure waterproofness, and durability and weather resistance of the concrete structure can be improved.

1 is a process flowchart of a method for manufacturing a marine concrete structure using a phase change material according to an embodiment of the present invention.
Figure 2 is a photograph showing the particle shape of the paraffin wax, the main raw material of the phase change material when manufacturing a marine concrete structure using a phase change material according to an embodiment of the present invention.
3 is a detailed process flowchart of the phase change material manufacturing step of FIG.
Figure 4 is an electron microscope (SEM) photograph after the standard curing test specimens dried at room temperature in the marine concrete structure using a phase change material according to an embodiment of the present invention.
Figure 5 is an electron microscope (SEM) photograph after the standard curing test specimen oven dried at 105 ℃ in a marine concrete structure using a phase change material according to an embodiment of the present invention.
6 is an electron micrograph (SEM) of the thermal insulation curing test specimen in the marine concrete structure using a phase change material according to an embodiment of the present invention.
7 and 8 are electron microscopy (SEM) pictures for comparing the drying method of the standard curing test specimen in the marine concrete structure using a phase change material according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

First, Korean Patent No. 10-683131, filed and registered by the same applicant and inventor of the present invention, discloses an invention named "phase change material for concrete and its manufacturing method", which is referred to in the present specification. And form part of the present invention.

1 is a process flow diagram of a method for manufacturing a marine concrete structure using a phase change material according to an embodiment of the present invention, Figure 2 is a main phase of the phase change material when manufacturing a marine concrete structure using a phase change material according to an embodiment of the present invention It is a photograph showing the particle shape of paraffin wax as a raw material.

Referring to Figure 1, the marine concrete structure manufacturing method using a phase change material according to an embodiment of the present invention, first, 38 to 42 parts by weight of paraffin wax having a phase change temperature of 60 ~ 90 ℃, polyoxyethylene stearyl acid Phase change for concrete consisting of 8-12 parts by weight of nonionic surfactants based on ethers of poly oxyethylene strearyl ether, 18-22 parts by weight of anionic surfactants of sulfate or polycarbonate series, and 28-32 parts by weight of water To prepare the material ( S110 ).

Specifically, the paraffin wax used for the phase change may vary depending on the molecular weight and molecular formula of the phase change temperature range, among which the phase change temperature is appropriate within the range of 40 ~ 130 ℃. More preferably, paraffin wax having a phase change temperature within a range of 60-90 ° C. is used because the temperature of the concrete or mortar is usually 60-90 ° C. when it is manufactured according to the rising temperature of concrete. For example, the particles of paraffin wax applied to the embodiment of the present invention form a spherical shape, and the particle diameter thereof is about 13 to 21 μm, as shown by reference numeral A in FIG. 2.

In addition, since the concrete to which the phase change material is applied should use water, paraffin wax should be emulsified using a surfactant. In this case, the surfactant used is manufactured to form an electric double layer.

In addition, the emulsifier is more stable when the high and low HLB value is generally used at the same time, it is preferable that an anionic surfactant and a nonionic surfactant are used together. At this time, when the HLB value is too high or low, a change in the amount of air required according to the change in the interfacial tension in the cement system occurs and the difficulty in practical application increases.

Here, the HLB (hydrophile lipophile balance) value is an indicator for uniformly classifying the characteristics of various types of surfactants and using them for each use. In this case, the surfactant is a hydrophilic group and a lipophilic group in one molecule. Since the lipophilic group is shared, the properties of the surfactants are classified numerically by the strength of the hydrophilic and lipophilic strengths of the respective groups. The HLB value is in the range of 0 to 20, and the smaller the value, the stronger the lipophilic property of the whole molecule, and the larger the hydrophilicity. The relationship with the application is that the HLB values 1 to 3 are antifoaming agents, 3 to 6 are W / O type emulsifiers, 7 to 9 are wetting agents, 8 to 18 are O / W type emulsifiers, 13 to 15 are cleaning agents, and 15 to 18 are It is suitable as a solubilizer.

It is preferable that such a surfactant does not exceed 30% of the total weight fraction, and if it is higher than this, there is a disadvantage that the compressive strength of the concrete is reduced by causing bubbles of concrete due to the change of the interfacial tension. Therefore, it is more preferable that the ratio of surfactant is 20% or less.

In addition, a nonionic surfactant and an anionic surfactant are used together as a surfactant, and a polyoxyethylene sterearyl ether series is used as a nonionic surfactant, and as an anionic surfactant, a hydrophilic When the large sulphate or polycarbonate series is used, it forms a stable emulsion phase and is more suitable for the properties of concrete.

Next, the phase change material is mixed in concrete ( S120 ), and then the concrete in which the phase change material is mixed is cured at high temperature ( S130 ). At this time, the concrete mixed with the phase change material is cured at a high temperature at a temperature of 60 ~ 90 ℃.

Next, paraffin wax of the phase change material is dissolved in the internal pores of the concrete to prevent the movement of moisture in the concrete to enhance water tightness to coat the pores ( S140 ). At this time, the water absorption coefficient of the mortar for concrete heated and cured by mixing the phase change material is 0.03.

According to an embodiment of the present invention, after incorporating a phase change material into concrete, curing at a high temperature of 60 ~ 90 ℃ by dissolving paraffin wax in the pores of the concrete to coat the pores to prevent the movement of moisture to improve water-tightness have.

At this time, it does not affect the physical properties such as the amount of air, slump, compressive strength of the concrete. In addition, as a result of comparing the water absorption coefficient values obtained in the mortar experiment for concrete, the water absorption coefficient of the general mortar without mixing the phase change material is 0.11, the water absorption coefficient of the three-component cement mortar is 0.13, but the embodiment of the present invention The water absorption coefficient of mortar containing phase change material was 0.03. At this time, in the experiment according to an embodiment of the present invention, the phase change material is mixed mortar is heat curing at least 60 days at 60 ℃.

That is, in the marine concrete structure using the phase change material according to an embodiment of the present invention, the water absorption coefficient of the mortar incorporating the phase change material is 0.03, which is very low compared to the water absorption coefficient of the general mortar, thereby improving watertightness. Able to know.

On the other hand, Figure 3 is a specific process flow diagram of the phase change material manufacturing step of FIG.

Referring to Figure 3, in the phase change material manufacturing process in the marine concrete structure manufacturing method using a phase change material according to an embodiment of the present invention, 38 to 42 parts by weight of paraffin wax and 8 to 12 parts by weight of nonionic surfactant After mixing ( S111 ), the melting point is heated above ( S112 ).

Next, using a homomixer, high speed stirring at 3000rpm or more ( S113) . In this case, when the amount of paraffin wax is large, in the emulsification process, it is often difficult to disperse it as agglomerates into wax lumps. In addition, when the amount of the wax is less than this, there is a disadvantage that the amount of the wax is too large to decrease the relative amount of wax for controlling the temperature of the concrete or mortar.

Next, 28 to 32 parts by weight of water and 18 to 22 parts by weight of anionic surfactant are added ( S114 ), and a high speed stirring is performed at 3000 rpm or more using a homomixer ( S115 ).

Next, in a hot bath of 5 ° C or less, the emulsion is quenched to have a temperature of 20 ° C or less to obtain a creamy phase change material ( S116 ).

Next, 48 to 52 parts by weight of water and 8 to 12 parts by weight of a silicone- or fatty acid-based defoamer may be added to the cream-like phase change material to obtain a phase change material suitable for concrete with low viscosity. S117 ).

In this case, water may be properly added in the middle of the manufacturing process to maintain viscosity, but may have too much energy consumption during cooling or excessively large emulsion particles, which may adversely affect compressive strength when used in concrete. Can be.

In addition, the phase change material should not cause a problem of mixing with other concrete admixtures, and when the reaction retardant such as sodium gluconate is included, the calorific value can be further lowered. Such reaction retardants may include all of a series of cement reaction retardants, such as gluconate, citric acid salts, tartaric acid salts, sugars, magnesium silicate salts, and acrylate salts.

On the other hand, Figure 4 is an electron microscope (SEM) picture of the standard curing test specimen after drying at room temperature in a marine concrete structure using a phase change material according to an embodiment of the present invention, Figure 4a) is a 2000 times magnified picture, 4B is an enlarged photograph 5000 times.

In addition, Figure 5 is an electron microscope (SEM) picture of the standard curing test specimen oven dried at 105 ℃ in a marine concrete structure using a phase change material according to an embodiment of the present invention, Figure 5a) is enlarged 2000 times It is a photograph, and b) of FIG. 5 is a 5000 times enlarged photograph.

In addition, Figure 6 is an electron micrograph (SEM) of the thermal insulation curing test specimen in a marine concrete structure using a phase change material according to an embodiment of the present invention, Figure 5a) is a 2000 times magnification photograph, Figure 5b) Is 5000 times magnified.

Marine concrete structure using a phase change material according to an embodiment of the present invention, as shown in Figure 4 to 6, according to an embodiment of the present invention, paraffin wax, nonionic surfactant, anionic surfactant and water By maximizing the watertightness by incorporating the phase change material into concrete and curing at high temperature, it is possible to enhance the durability of the marine concrete structure affected by the diffusion movement of salts through water.

On the other hand, Figures 7 and 8 are electron microscopy (SEM) pictures for comparing the drying method of the standard curing test specimen in the marine concrete structure using a phase change material according to an embodiment of the present invention, Figure 7a) is a standard curing It is a photograph which shows that the test body was dried at normal temperature, and b) of FIG. 7 is a photograph which shows oven drying of the standard curing test body at 105 degreeC. 8 is a photograph showing that the standard curing test body is dried at room temperature, and FIG. 8 b is a photograph showing the oven drying of the standard curing test body at 105 ° C.

Therefore, the marine concrete structure using a phase change material according to an embodiment of the present invention by maximizing water tightness by drying the concrete mixed with the phase change material at high temperature curing, for example, 105 ℃, salt-based salt It is possible to enhance the durability of offshore concrete structures affected by the diffusion movement of.

Accordingly, the marine concrete structure using the phase change material according to the embodiment of the present invention can ensure water resistance by forming watertight concrete, and can improve the durability and weather resistance of the concrete structure.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

Claims

In the method of manufacturing marine concrete structure,
a) 38 to 42 parts by weight of paraffin wax having a phase change temperature of 60 to 90 ° C., 8 to 12 parts by weight of a nonionic surfactant based on poly oxyethylene strearyl ether, sulfate series or polycarbon Preparing a phase change material for concrete comprising 18 to 22 parts by weight of anionic surfactant based on an acid salt, and 28 to 32 parts by weight of water;
b) incorporating the phase change material into concrete;
c) hot curing the concrete mixed with the phase change material; And
d) coating the pores by dissolving paraffin wax of the phase change material in the internal pores of the concrete to prevent water from moving inside the concrete to enhance water tightness;
Marine concrete structure manufacturing method using a phase change material comprising a.

The method of claim 1,
The method of manufacturing a marine concrete structure using a phase change material, characterized in that the water absorption coefficient of the mortar for concrete heated by curing the phase change material is 0.03.

The method of claim 1, wherein step a) comprises:
a-1) mixing 38 to 42 parts by weight of paraffin wax and 8 to 12 parts by weight of a nonionic surfactant;
a-2) heating the mixture of the paraffin wax and the nonionic surfactant above the melting point;
a-3) rapidly stirring the mixture at 3000 rpm using a homomixer;
a-4) adding 28 to 32 parts by weight of water and 18 to 22 parts by weight of anionic surfactant to the mixture;
a-5) rapidly stirring the mixture to which the water and the anionic surfactant are added using a homomixer;
a-6) quenching the emulsion at a temperature of 5 ° C. or lower so that the temperature of the emulsion is 20 ° C. or lower to firstly form a creamy phase change material; And
a-7) changing to a final phase change material suitable for concrete by adding 48 to 52 parts by weight of water and 8 to 12 parts by weight of a silicone- or fatty acid-based antifoaming agent to the first cream-like phase change material.
Marine concrete structure manufacturing method using a phase change material comprising a.

The method of claim 1,
The c) step is a marine concrete structure manufacturing method using a phase change material, characterized in that the high temperature curing at a temperature of 60 ~ 90 ℃.

A marine concrete structure manufactured by the method of manufacturing a marine concrete structure using the phase change material of any one of claims 1 to 4.