KR102187176B1 - Method For Providing Reinforced Concrete Service Life Considering Climate Change and Crack Effect And Recording Medium Thereof - Google Patents

Abstract

The model and program for predicting the useful life of reinforced concrete considering climate change and cracking of the present invention predicts the degree of carbonation of reinforced concrete in response to the continuously increasing carbon dioxide due to global warming, and calculates the possibility of corrosion of reinforced reinforced concrete. There is an advantage in that the useful life can be more accurately evaluated.
The prediction model and program of the present invention has the advantage of being able to easily use even non-professionals without specialized knowledge because the effective life prediction result of reinforced concrete is automatically calculated by putting only the mixing factor information, crack information and climate change information. In addition, it can be applied to various climate change scenarios, concrete mix and crack information, and various types of cement, as well as showing a tendency that is almost similar to the actual experimental results, so that the accuracy is very excellent.
Therefore, it is expected that the model and program for predicting the useful life of reinforced concrete in consideration of climate change and cracking of the present invention can be applied to the concrete material field in various ways and used in the construction of safe structures responding to climate change.

Description

Method For Providing Reinforced Concrete Service Life Considering Climate Change and Crack Effect And Recording Medium Thereof}

The present invention relates to a method for providing the effective life of reinforced concrete in consideration of climate change and cracks, and a medium recording the same.

Carbonation is a major factor in the corrosion of rebars in reinforced concrete structures. When carbonation proceeds, the pH of the solution present in the pores of the concrete drops to the level of 9, which destroys the passive film that protects the reinforcing bar and induces corrosion of the rebar. The reinforced concrete structure has low tensile sensitivity and has a high probability of cracking due to its own load or environmental factors at the beginning of construction. When cracks occur in the reinforced concrete structure, carbon dioxide in the air penetrates into the reinforced concrete. The infiltrated carbon dioxide accelerates the carbonation action of cement and shortens the life of reinforced concrete.

Global warming continues to increase the concentration of carbon dioxide in the atmosphere and the average temperature of the planet. Therefore, in order to accurately predict the lifespan of reinforced concrete, it is necessary to closely observe the degree of corrosion of the reinforced reinforcement by considering the increase rate of carbon dioxide in response to climate change and the resulting increase rate of carbonation of cement in the reinforced concrete as variables.

Korean Patent No. 10-1897551 discloses a program for developing a method for evaluating carbonation of high-volume slag concrete in consideration of environmental factors including carbon dioxide concentration, and predicting the carbonation depth of concrete using this; Papadakis (2000) has conducted studies on the carbon dioxide diffusion coefficient and carbonation resistance of concrete according to the composition and surrounding environment of concrete; Song et al. (2006) conducted a simulation study on the carbonation depth of reinforced concrete with cracks and reinforced concrete without cracks.

However, the previous study provided only the prediction result of the degree of carbonation over time for the concentration of carbon dioxide, and did not take into account the change in the concentration of carbon dioxide in the atmosphere, which continuously rises due to global warming and climate change. Therefore, development of a method of predicting the degree of carbonation by integrating the degree of hydration of cement according to the composition ratio, crack information of reinforced concrete, and the amount of carbon dioxide increasing due to global warming and climate change and predicting the life of reinforced concrete through this need.

The patent documents and references mentioned in this specification are incorporated herein by reference to the same extent as if each document was individually and clearly specified by reference.

Korean Patent Registration No. 10-1897551

Papadakis, V.G. Cem. Concr. Res. 2000, 30, 291-299. Song, H.W., et, al. Cem. Concr. Res. 2006, 36, 979-989.

In order to solve the above problems, the present invention provides a method for predicting the useful life of reinforced concrete in consideration of climate change and cracks, including a cement hydration model and a carbonation reaction model, and a program using the same.

The carbonation reaction model of the present invention predicts the degree of carbonation by simultaneously reflecting the crack information of concrete and the increasing trend of carbon dioxide concentration according to the greenhouse gas scenario, so that the useful life of reinforced concrete can be more accurately predicted.

Therefore, an object of the present invention is to calculate the corrosion probability and useful life of reinforced concrete according to time by inputting information on mixing elements of concrete, crack information and climate change information, and using a model for predicting the useful life of reinforced concrete considering climate change and crack. After that, it is to provide a method for predicting the useful life of reinforced concrete that provides it on the screen and its program.

Other objects and technical features of the present invention are presented in more detail by the following detailed description, claims, and drawings.

In the present invention, when a program for providing prediction of the useful life of reinforced concrete considering climate change and cracks is executed in a computer, the program provides a compounding element information input window, a crack information input window, and a climate change information input window on a screen. ; When the mixing factor information, crack information, and climate change information are entered into the mixing factor information input window, crack information input window, and climate change information input window, respectively, the reinforced concrete life expectancy model considering climate change and cracks is used. Calculating the corrosive potential and useful life over time; And providing the calculated result on the screen; a method for predicting the useful life of reinforced concrete in consideration of climate change and cracks, and a program thereof.

으로 표현되며 상기 P _f 는 부식 발생 확률을 의미하고, 상기 g(t)는 부식발생 기준을 의미하며, 상기 N은 몬테카를로 방법의 계산횟수를 의미하는 것을 특징으로 한다.The model for predicting the useful life of reinforced concrete in consideration of the climate change and cracking is the Monte Carlo method equation:

Wherein P _f denotes a probability of occurrence of corrosion, g(t) denotes a corrosion occurrence criterion, and N denotes the number of calculations of the Monte Carlo method.

In addition, the step of calculating the corrosion potential and useful life of the reinforced concrete over time is to calculate the cement hydration degree ( α ), the amount of voids ( ε ), and the amount of substances (CH and CSH) that can be generated by the carbonation reaction and use them. Calculating the equivalent carbon dioxide diffusion index ( D _eq ); Calculate the equivalent carbon dioxide diffusion index ( D _eq ), the amount of carbon dioxide, and the amount of substances (CH and CSH) that can be generated by the carbonation reaction, and use this to calculate the carbonation depth ( CR ) and the carbonation depth increase ( dx _c ). Step to do; And calculating the corrosion occurrence criterion ( g (t) ) in consideration of the carbonation depth ( x _c ) and the cover thickness of concrete ( CV ), and calculating the corrosion potential and useful life of the reinforced concrete using the Monte Carlo method. Include more.

The model and program for predicting the useful life of reinforced concrete considering climate change and cracking of the present invention predicts the degree of carbonation of reinforced concrete in response to the continuously increasing carbon dioxide due to global warming, and calculates the possibility of corrosion of reinforced reinforced concrete. There is an advantage in that the useful life can be more accurately evaluated.

The prediction model and program of the present invention has the advantage of being able to easily use even non-professionals without specialized knowledge because the effective life prediction result of reinforced concrete is automatically calculated by putting only the mixing factor information, crack information and climate change information.

In addition, it can be applied to various climate change scenarios, concrete mix and crack information, and various types of cement, as well as showing a tendency that is almost similar to the actual experimental results, so that the accuracy is very excellent.

Therefore, it is expected that the model and program for predicting the useful life of reinforced concrete in consideration of climate change and cracking of the present invention can be applied to the concrete material field in various ways and used in the construction of safe structures responding to climate change.

1 shows a result of predicting a change in carbon dioxide concentration and air temperature in air according to a greenhouse gas scenario (RCP).
2 shows a flowchart of a program for predicting the useful life of reinforced concrete in consideration of climate change and cracking of the present invention.
3 shows a screen in which the program for predicting the useful life of reinforced concrete considering climate change and cracks of the present invention is executed.
4 shows a screen in which the calculation result of the reinforced concrete useful life prediction program considering climate change and cracking of the present invention is output.
5 shows the result of outputting the calculation result of the reinforced concrete useful life prediction program in consideration of climate change and cracking of the present invention in Excel format.
6 shows the steps of calculating the possibility of reinforcement corrosion and the useful life of reinforced concrete in the reinforced concrete useful life prediction program in consideration of climate change and cracking of the present invention.
7 shows the result of comparing the carbonation depth prediction result calculated by the reinforced concrete useful life prediction program in consideration of climate change and cracking of the present invention with the experimentally analyzed carbonation depth measurement result.
8 shows the results of analyzing the parameters of the reinforced concrete useful life prediction program considering climate change and cracks of the present invention.

In the present invention, various modifications may be made and various embodiments may be provided. Specific embodiments will be illustrated in the drawings and described in detail. The above description is not intended to limit the present invention to specific embodiments, and it is to be understood that it includes all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination of one or more other features described in the specification. It is to be understood that the presence or addition of numbers, steps, actions, components, parts or combinations thereof does not preclude the possibility of preliminary exclusion.

In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this application. Does not.

In the description with reference to the accompanying drawings, the same elements are assigned the same reference numerals regardless of the reference numerals, and redundant descriptions thereof will be omitted. In describing the present invention, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In the present invention, the subject performing the method for providing the effective life of reinforced concrete in consideration of climate change and cracking may be an overall system that drives a program. The system may be a control unit or a processor that generally controls a system or device driving a program. Accordingly, the method of providing the reinforced concrete useful life in consideration of climate change and cracking of the present invention is composed of a program which is a kind of software, and the program can be executed in a system, a computer, or a processor.

In the present invention, the subject of performing the method for providing the reinforced concrete useful life in consideration of climate change and cracks may be various computer devices. The computer device may be a computer, a control unit of the computer, or a processor.

The present invention relates to a method for providing a reinforced concrete useful life in consideration of climate change and cracks. Since the reinforced concrete has a weak tensile strength, a lot of cracks are generated. Carbon dioxide in the air may penetrate into the concrete through the crack. The carbon dioxide penetrating through the crack reacts with calcium hydroxide in concrete and is carbonated to calcium carbonate rapidly. The carbonation reaction lowers the pH of the solution existing in the inner pores to a level of 9, and the solution in the pores with the lowered pH destroys the passivation film protecting the reinforcing bar and induces corrosion of the reinforcing bar. When the reinforcing bar is corroded, an expansion pressure of the reinforcing bar is generated due to rust, which further induces cracking of the concrete inside the concrete, thereby reducing the service life of the reinforced concrete.

Due to climate change such as global warming, the concentration of carbon dioxide in the air and the temperature of the air are continuously increasing. Does the change in carbon dioxide concentration and temperature continue to threaten the global ecosystem? Therefore, international environmental organizations have prepared a greenhouse gas scenario and used it as basic data for each country's environmental policy. A representative greenhouse gas scenario is the representative concentration pathways (RCP) scenario. The RCP scenario is an index for determining a greenhouse gas emission reduction policy for each social and economic sector as a countermeasure for the climate change scenario after setting the greenhouse gas concentration value.

According to the RCP scenario, the concentration and temperature of carbon dioxide present in the air tend to increase continuously (see FIG. 1). The above RCP scenario is a scenario in which the earth can recover the impact of human activities by itself (RCP 2.6), a scenario in which a GHG reduction policy is implemented considerably (RCP 4.5), in a case in which GHG emissions are emitted in the current trend without reduction. There is a scenario (RCP 8.5). In the present invention, the RCP scenario is used as climate change information to predict and provide the change in the useful life of reinforced concrete due to carbonation reaction of carbon dioxide.

2 shows a flow chart of a method for predicting the useful life of reinforced concrete in consideration of climate change and cracks according to the present invention.

When a program for providing prediction of the useful life of reinforced concrete taking into account climate change and cracks is executed in a computer (S210), the program is a mixing element information input window for entering the numerical value of the mixing element for producing concrete, A crack information input window for inputting a numerical value and a climate change information input window for selecting an RCP scenario are provided on the screen (S220).

The compounding element information input window includes an input window for inputting water, cement, fine aggregate, coarse aggregate, and values of the curing period before carbonation, respectively, and the crack information The input window includes an input window for inputting the values of crack width and crack depth, and the climate change information input window is an input for selecting one of RCP 2.6, RCP 4.5 and RCP 8.5. Includes a window.

When the input is completed through the mixing factor information input window, the crack information input window, and the climate change information input window (S230), the program uses the reinforced concrete useful life prediction model in consideration of climate change and cracks at the time of the reinforced concrete. Corrosion probability and durability according to the life is calculated (S240). The calculated result is provided on the screen (S250).

3 shows a screen in which the program for providing the useful life of reinforced concrete in consideration of climate change and cracks of the present invention is executed. Enter the values of water, cement, fine aggregate, coarse aggregate, and curing time befor carbonation (days) in the concrete miture. It includes an input window that you can do. The crack and exposure conditions are located below the compounding element information input window. The crack and exposure information input window is composed of a crack information input window and a climate change information input window. The crack information input window may input values of crack width and crack depth, and the climate change information input window may select and input RCP.

On the side of the crack and exposure information input window, a window for displaying the calculation result as a graph is located, and under the crack and exposure information input window, an execution button for executing a program after all information is entered is located.

Figure 4 shows that the information used in the embodiment is input and the corrosion probability result of the reinforced concrete calculated through the calculation over time is output in a graph form.

5 shows the result of converting the result output in the graph form to an Excel format and saving it. The result saved in Excel can be processed by extracting only the desired data through an Excel program, and data can be modified and edited.

The model for predicting the useful life of reinforced concrete considering climate change and cracking of the present invention is a method of calculating the carbonation durability life using a probabilistic method. The present invention calculates the corrosion probability of reinforced reinforced concrete in reinforced concrete by carbonation reaction through the Monte Carlo method. The above calculation result shows that P _{f =0.1, the} corresponding use period is the concrete durability life.

The method for predicting the useful life of reinforced concrete in consideration of climate change and cracking of the present invention is expressed by the following Equation 1.

The P _f denotes the probability of occurrence of corrosion, the g (t) denotes a criterion for the occurrence of corrosion in consideration of the thickness of the concrete and the depth of carbonation, and N denotes the number of calculations of the Monte Carlo method.

In the method for predicting the useful life of reinforced concrete in consideration of climate change and cracking, the step of calculating the corrosion potential and useful life of the reinforced concrete over time may include the following detailed steps (see FIG. 6):

Calculating the cement hydration degree ( α ), the amount of voids ( ε ), and the amount of substances (CH and CSH) that can be generated by the carbonation reaction, and calculating the equivalent carbon dioxide diffusion index ( D _eq ) using the same;

Calculate the equivalent carbon dioxide diffusion index ( D _eq ), the amount of carbon dioxide, and the amount of substances (CH and CSH) that can be generated by the carbonation reaction, and use this to calculate the carbonation depth ( CR ) and the carbonation depth increase ( dx _c ). Step to do; And

Calculating the corrosion occurrence criterion ( g(t) ) in consideration of the carbonation depth ( x _c ) and the cover thickness ( CV ) of concrete, and calculating the corrosion potential and useful life of the reinforced concrete using the Monte Carlo method.

Hereinafter, a model for predicting the useful life of reinforced concrete considering climate change and cracking will be described in detail.

1. Hydration reaction model

1.1. Cement Hydration Model

The water ring reaction model applied in this model is the shrinking-core model. The model is expressed as Equation 2 below.

The k _d denotes a reaction coefficient, D _e denotes an effective diffusion coefficient of moisture in consideration of CSH gel, k _ri denotes a reaction rate coefficient of the inorganic compound of cement, and α denotes the weight fraction of the inorganic compound ( g _i ) means the degree of cement hydration that can be calculated from the reactivity of inorganic compounds ( α _i ), where ν means the stoichiometric ratio of water and cement (=0.25), and w _g is the CSH gel It means the number of physical and chemical bonds (=0.15), where ρ _c and ρ _W mean the density of cement and water, respectively, the C _w-free means the total amount of external moisture in the CSH gel, and r ₀ is not It means the radius of the cement particles, the S _w means the effective surface area of the cement in contact with water, the S ₀ means the total surface area.

In addition, the cement hydration degree ( α ) is calculated by the method of Equation 3 below.

The g _i means the weight fraction of the inorganic compound, and the α _{i (i=1,2,3, and 4)} is the cement component (cement C ₃ S, C ₂ S, C ₃ A, and C _{) that} is an inorganic compound ₄ AF).

1.2 Equation of each coefficient in the sign language model

1.2.1 Reaction coefficient

The reaction coefficient ( k _d ) means the reaction coefficient, and it can be inferred from the equation that induces the degree of hydration. The reaction coefficient is expressed as in Equation 4 below.

The B and C denote the initial film formation rate and the film disintegration rate, respectively, and α denotes the reactivity of the cement components C ₃ S, C ₂ S, C ₃ A, or C ₄ AF.

1.2.2 Effective diffusion index of moisture

D _e means the effective diffusion coefficient of water in consideration of CSH gel, and is expressed as Equation 5 below.

The D _e means the initial diffusion index, and α means the reactivity of the cement constituents C ₃ S, C ₂ S, C ₃ A, or C ₄ AF.

1.2.3 Capillary pore number

The moisture content of the cement is determined by the number of pores in the cement. Therefore, in the present invention, the total amount of external moisture ( C _w-free ) of the CSH gel was determined. The C _w-free is expressed as Equation 6 below.

The C ₀ and W ₀ denote the volume of the cement and the volume of water, respectively, in the blending, and the r denotes the accessibility of moisture that can penetrate from the outer film of the cement particles to the unhydrated portion of the cement. If the ratio of water and binder is 0.4 or more, r = 1.0, and if the ratio of water and binder is 0.4 or less, it is determined to be 1.0 or more through the equation r = 2.6-4( W ₀ /[ C ₀ +P]). The P means the volume of the mineral admixture.

1.2.4 Response index according to temperature

The reaction index according to temperature is expressed as Equations 7, 8, 9, and 10 below according to Arrhenius's law.

B means a film formation rate, B ₂₀ means a film formation rate at 20°C, β ₁ means a temperature sensitivity coefficient, and T means an absolute temperature.

C means a film disintegration rate, C ₂₀ means a film disintegration rate at 20° C., β ₂ means a temperature sensitivity coefficient, and T means an absolute temperature.

The k _ri denotes the reaction rate coefficients of the inorganic compound in the cement, and the k _ri20 means a reaction rate coefficient in a 20 ℃, wherein the β ₃ represents a temperature coefficient of sensitivity, the T indicates the absolute temperature.

The D _e means the effective diffusion coefficient of water considering the CSH gel, the D _e20 means the effective diffusion coefficient at 20 ℃, the β ₄ means the temperature sensitivity coefficient, and the T means the absolute temperature do.

1.2.5 CH, CSH and concrete porosity

The amount of CH ( CH(t) ), the amount of CSH ( CSH(t) ) and the concrete porosity ( ε(t) ) were calculated through Equations 11, 12, and 13 below.

The RCH _CE means the volume of CH produced in 1 g of cement, the C ₀ means the volume of cement, and the α means the cement hydration degree.

The f _S,C refers to the amount of SiO _{2 in} the cement chemical component, C ₀ refers to the volume of the cement, and α refers to the cement hydration degree.

The W means the volume of moisture, the ρ _W means the density of water, the C ₀ means the volume of the cement, the α means the cement hydration degree, the △ ε _C is the carbonation reaction Means reduced voids.

2. Carbonation reaction model

2.1 Equivalent carbon dioxide diffusion index

The calculation of the equivalent carbon dioxide diffusion index ( D _eq ) was performed by calculating the carbon dioxide diffusion index ( D ) of the concrete without cracking and the carbon dioxide diffusion index (D _cr /D ₂₈ ) of the cracked part.

First, the carbon dioxide diffusion index ( D ) of the concrete without cracking was calculated. The calculation was performed using Equation 14 below.

The A denotes a coefficient related to the carbonation diffusion index, ε denotes the concrete porosity, the C ₀ and W ₀ denotes the volume of the cement and the water in the mixture, respectively, and ρ _c denotes the ρ _W It means the density of cement and water, respectively, where α means a coefficient related to the carbonation diffusion index, and RH means the relative humidity.

Next, the carbon dioxide diffusion index (D _cr ) of the crack was calculated. The above calculation was performed using Equation 15.

The D _cr denotes the carbon dioxide diffusion index of the cracked portion, the D ₂₈ denotes the carbon dioxide diffusion index of the crack-free concrete after 28 days curing, and W and C denote the moisture and the volume of cement.

The equivalent carbon dioxide diffusion index ( D _eq ) was calculated by considering the calculated carbon dioxide diffusion index ( D ) of the concrete without cracking and the carbon dioxide diffusion index (D _cr ) of the cracked portion as shown in Equation 16 below.

The D _cr refers to the carbon dioxide diffusion index of the cracked part, the D refers to the carbon dioxide diffusion index of the concrete without cracking, the ω refers to the area of the crack, and ι refers to the distance between cracks do.

The effect of temperature on the carbon dioxide diffusion index was considered using Arrhenius's Law equation. The influence of the carbon dioxide diffusion index according to temperature ( D(T) ) is expressed as Equation 17 below.

The D _ref denotes a carbon dioxide diffusion index at a reference temperature, D(T) denotes a carbon dioxide diffusion index at a temperature T, and β denotes an active energy.

2.2 Carbonation depth calculation

The carbonation depth ( CR ) by carbon dioxide and the increase in the carbonation depth over time ( dx _c ) were calculated. The calculation of the carbonation depth and the amount of increase in the carbonation depth was performed by Equations 18 and 19.

The [ CO ₂ ] ₀ denotes the carbon dioxide concentration, the D _eq denotes an equivalent carbon dioxide diffusion index, and the [CH] and [CSH] denote the amount of CH and the amount of CSH that can be generated by the carbonation reaction.

The CR denotes the carbonation depth, and dt denotes an increase in time.

2.3 Carbonation endurance calculation using probabilistic method

The probability of corrosion of reinforced reinforcing bars in reinforced concrete according to carbonation reaction is calculated through the Monte Carlo method. The calculation formula for the corrosion probability of reinforcing bars in reinforced concrete according to the carbonation reaction is shown in Equation 1. P _{f =0.1 The} corresponding service life is the concrete durability life. In Equation 1, P _f denotes a probability of occurrence of corrosion, g(t) denotes a corrosion occurrence criterion, and N denotes the number of calculations of the Monte Carlo method. The corrosion occurrence criterion g(t ) is expressed as Equation 20 below.

The CV means the coating thickness of the concrete and the x _c means the carbonation depth.

Example

Example 1: Calculation of the carbonation depth of cracked concrete

The carbonation depth of the cracked concrete was calculated using the model equation of the present invention. The water-cement ratio (WC) of concrete was 0.45, 0.55, and 0.65, and the crack widths were 0 ㎜, 0.05 ㎜, 0.15 ㎜ and 0.25 ㎜. The calculation results were compared with the experimentally analyzed carbonation depth. 7 shows the result of comparing the carbonation depth of concrete calculated using the model equation of the present invention and the carbonation depth experimentally analyzed (see FIG. 7).

Example 2: Prediction of durability life for carbonation of cracked concrete

The carbonation life prediction program was developed using the cement hydration model and the carbonation model, and the carbonation service life of cracked concrete was predicted. The interface of the program is shown in FIG. 3. For climate change scenarios, RCP 4.5, RCP 8.5, and RCP 2.6 were used. After entering concrete mix, external environmental conditions and climate change scenario information, the program was executed to predict the durability life.

4 shows the output result of actually executing the program. In FIG. 4, a water-cement ratio (W/C) of 0.45, a crack width of 0.1, a cover depth of 35 mm, and a climate scenario RCP of 4.5 were set. As a result of the program implementation, when climate change was not considered, the durable life was 29.889 years, and when climate change was considered, the durable life was 26.876 years, which was predicted to decrease by about 10% due to climate change. In addition, after setting the water-cement ratio of 0.45 or 0.65, the crack width of 0.05, 0.15, or 0.25, the cover thickness of 25 or 35 mm, and the climate scenario RCP 8.5, the program was executed to predict the durability life. The calculation results are shown in Table 1 below.

As a result of the calculation, it was confirmed that the endurance life when climate change is considered decreases compared to the endurance life without climate change.

A parameter analysis was performed for the reinforced concrete useful life prediction program in consideration of climate change and cracks of the present invention. To this end, the ratio of the durable life considering climate change and the durable life without climate change, that is, the relative durable life, was calculated and analyzed.

8 shows the result of calculating the relative durability life. As a result of the analysis, it was confirmed that the relative durable life decreased linearly with the increase of the durable life without considering climate change.

In summary, the reinforced concrete useful life prediction model and program in consideration of climate change and cracks of the present invention have the advantage of being able to easily use even non-professionals without specialized knowledge because only the above parameters are input and the durability life prediction result is automatically calculated.

In addition, it can be applied to various climate change scenarios, concrete mix and crack information, and various types of cement, as well as showing a tendency that is almost similar to the actual experimental results, so that the accuracy is very excellent.

Therefore, it is expected that the model and program for predicting the useful life of reinforced concrete in consideration of climate change and cracking of the present invention can be applied to the concrete material field in various ways and used in the construction of safe structures responding to climate change.

The specific embodiments described herein are meant to represent preferred embodiments or examples of the present invention, and the scope of the present invention is not limited thereby. It will be apparent to those skilled in the art that variations and other uses of the invention do not depart from the scope of the invention described in the claims of this specification.

Claims (7)

In the method for predicting the useful life of reinforced concrete considering climate change and cracks,
When a program for providing prediction of the useful life of reinforced concrete considering climate change and cracks is executed in the computer, the program provides a compounding element information input window, a crack information input window, and a climate change information input window on a screen;
When the mixing factor information, crack information, and climate change information are input into the mixing factor information input window, the crack information input window, and the climate change information input window, respectively, the reinforced concrete useful life prediction model considering climate change and cracks is used. Calculating the corrosion potential and useful life of the reinforced concrete over time; And
Providing the calculated result on a screen;
It is a method for predicting the useful life of reinforced concrete taking into account climate change and cracks including,
The model for predicting the useful life of reinforced concrete taking into account the climate change and cracking is the Monte Carlo method equation:

Is expressed as,
The P _f denotes the probability of occurrence of reinforced corrosion in reinforced concrete, the g(t) denotes a corrosion occurrence criterion considering the cover thickness and carbonation depth of the concrete, and N denotes the number of calculations of the Monte Carlo method,
The steps of calculating the corrosion potential and useful life of the reinforced concrete over time include the concrete porosity ( ε _(t) ), the amount of substances (CH and CSH) that can be generated by the carbonation reaction, and the carbon dioxide diffusion of the concrete without cracking. Calculating and calculating the equivalent carbon dioxide diffusion index ( D _eq ) considering the index (D) and the carbon dioxide diffusion index ( D _eq ) of the crack portion;
Carbonation depth ( CR ) using the amount of carbon dioxide predicted from the climate change information (CO ₂ (t)), the equivalent carbon dioxide diffusion index ( D _eq ), and the amount of substances (CH and CSH) that can be generated by the carbonation reaction ) And calculating and calculating an increase in carbonation depth ( dx _c ); And
Corrosion occurrence criterion ( g(t) ) is calculated by taking into account the carbonation depth ( x _c ) and the cover thickness ( CV ) of concrete, and using this, the possibility of corrosion of reinforced reinforcing bars in reinforced concrete (P _f ) And calculating the useful life; method for predicting the useful life of reinforced concrete in consideration of climate change and cracks, comprising: a.
The method of claim 1, wherein the compounding element information input window includes an input window for inputting water, cement, fine aggregate, coarse aggregate, and values of the curing period before carbonation, respectively. A method for predicting the useful life of reinforced concrete in consideration of climate change and cracks, comprising:
The effective life of reinforced concrete in consideration of climate change and cracks according to claim 1, wherein the crack information input window includes an input window for inputting values of crack width and crack depth. Prediction method.
The method of claim 1, wherein the climate change information input window comprises an input window for inputting values of representative concentration pathways.
delete The prediction of the useful life of reinforced concrete in consideration of climate change and cracks according to claim 1, wherein the calculated result is output in a graph form or the data output in a graph form is converted into an Excel file format and stored. Way.
A computer-readable recording medium in which a program capable of executing the method of claim 1 is recorded.

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