KR20130058629A - Apparatus for estimating thermal crack susceptibility of concrete and method using thereof - Google Patents

Abstract

PURPOSE: A device and a method for measuring the temperature cracking resistance of concrete are provided to measure the temperature cracking resistance under a controlled environment without the influences of an external environment. CONSTITUTION: A device(100) for measuring the temperature cracking resistance of concrete comprises a first restrictor(11), a second restrictor(12), a first measuring unit, and a second measuring unit. The first restrictor includes a second surface(11b) facing a first surface(11a) and has a closed figure shape. The second restrictor, which is arranged at a predetermined distance with space from the first restrictor, includes a third surface(12a) restraining a concrete test object which is interposed between the second and third surfaces and a fourth surface(12b) and has a closed figure shape. The first and second measuring units are arranged in the first and fourth surfaces, thereby measuring the strain rate of the test object.

Description

Apparatus for Estimating Thermal Crack Susceptibility of Concrete and Method using

The present invention relates to a temperature cracking resistance measuring apparatus and measuring method of concrete, specifically, to quantitatively evaluate the temperature cracking resistance to the heat of hydration of concrete so as to predict and evaluate the possibility of restraint stress and cracking due to the heat of hydration of concrete An apparatus and method for measuring are provided.

In recent years, there has been a trend of increasing the size of civil engineering and building structures using concrete, and mass concrete such as large offshore structures, bridges on long bridges, substructures such as bridges (piers, foundations, etc.), and foundations of high-rise buildings. ) The demand for structures is increasing.

In the case of such mass concrete structures, cracking occurs when the temperature stress inside the concrete due to the heat of hydration of cement and the external constraint condition exceeds the tensile strength. Therefore, in order to prevent and suppress cracking due to the heat of hydration of cement, the heat of hydration itself is reduced, or in the case of large mass concrete construction, the coping method is carried out by adjusting the one-time construction amount of concrete. An example of the prior art for reducing the heat of hydration is disclosed in Korean Patent Laid-Open No. 10-2011-0102749.

On the other hand, the temperature crack caused by the temperature change due to the heat of hydration can be evaluated by measuring the "temperature crack resistance," conventionally used a method of manufacturing a large concrete test specimen in the field to measure the temperature crack resistance, or concrete The adiabatic temperature rise and the strength expression value over time were obtained through laboratory tests. Based on the experimental results and the actual structure design, theoretical temperature cracking potential prediction simulations such as finite element analysis were performed.

However, such a conventional method causes inconveniences such as high cost and necessity of securing a test space for performing a large scale test in the field, and in the case of a simulation method by finite element analysis, structural design of a concrete structure This is accompanied by the inconvenience that the condition that must be prepared in advance.

Therefore, while predicting and evaluating the occurrence of constrained stress due to the volume change due to the heat of hydration of concrete and the possibility of cracking, it is urgently required to provide a device for measuring and measuring the temperature crack resistance of concrete that can solve the above problems.

Republic of Korea Patent Publication No. 10-2011-0102749 (2011. 09. 19. published)

The present invention is to solve the problems of the prior art as described above, an object of the present invention is to propose a temperature cracking resistance measuring apparatus and measuring method that can accurately and quantitatively measure and compare the possibility of cracking due to the heat of hydration of concrete.

That is, the external constraint can be applied to the concrete of the present invention according to the user's requirements, and the temperature cracking of the concrete in a controlled experimental environment to quantitatively evaluate the constrained stress and the occurrence of cracking due to the heat of hydration under such external constraint conditions. An object of the present invention is to provide an apparatus and a method capable of measuring resistance.

An apparatus for measuring temperature cracking resistance according to an embodiment of the present invention may include a first constraining body including a first surface and a second surface opposite thereto and having a closed figure shape; And a second constrained body disposed spaced apart from the first constrained body at a predetermined interval and having a closed figure shape with a third surface constraining the concrete test body between the second surface and a fourth surface opposite thereto. And a first measuring unit and a second measuring unit disposed on the first surface and the fourth surface to measure the strain of the test body.

The first and second constrainers may have shapes of circular rings having different diameters.

The first constrainer and the second constrainer may be made of an alloy material having a thermal expansion coefficient of 1/10 ⁶ or less. An adhesion preventing layer may be formed on the second surface and the third surface so that the test body and the first and second constrainers are not attached. The height of the first and second restraints may be at least three times the dimensions of the coarse aggregate of the test body. The first and second measurement units may include four or more strain gauges attached along the first and fourth surfaces, respectively.

In another embodiment of the present invention, the method for measuring temperature cracking resistance of the present invention includes a first design and a first restraint body having a closed shape and including a first surface and a second surface opposite to the mixing design step of the concrete test body. A temperature spaced apart from the restraint body at a predetermined interval, the temperature including a second restraint body having a closed shape with a third face that constrains the test body and a fourth face opposite to the second face; Providing a crack resistance measuring apparatus, charging the test specimen to the temperature crack resistance measuring apparatus, measuring strain on the first and fourth surfaces, and restraining the generation of the test specimen using the measured strain. Calculating a stress and measuring temperature cracking resistance using the calculated generated constraint stress.

After the compounding design step of the test body, the elastic modulus of the test body may be measured to determine the dimensions of the first and the second restraints.

In addition, the strain of the test body may be measured using the adiabatic temperature rise curve of the test body, and the generated binding stress of the test body may be calculated through the measured strain.

In addition, by measuring the compressive strength of the test body can be calculated the temperature cracking index together with the generated constraint stress.

According to one embodiment of the present invention, it is possible to provide a temperature crack resistance measuring apparatus and a measuring method capable of performing an experimental test without administering a high cost as in the conventional large-scale experimental test evaluation.

In addition, according to an embodiment of the present invention, it is possible to provide a temperature cracking resistance measuring apparatus and measuring method capable of quantitative comparison of the temperature cracking resistance in a controlled environment without being affected by the external environment.

And, according to an embodiment of the present invention, the user can design the temperature cracking resistance measuring apparatus to have a desired degree of restraint, and unlike the finite element analysis based on the design of the concrete structure, the concrete without considering the concrete structure It is possible to provide a temperature cracking resistance measuring apparatus and measuring method which can predict the possibility of cracking in advance in the compounding step through empirical experiments.

1 is a perspective view showing a temperature cracking resistance measuring apparatus according to an embodiment of the present invention, Figure 1b is a perspective view showing a state in which the concrete test specimen is filled in the temperature cracking resistance measuring apparatus of Figure 1a.
FIG. 2 is a plan view of the apparatus for measuring temperature crack resistance of FIG. 1A.
3 is a front view of the apparatus for measuring temperature crack resistance of FIG. 1A.
Figure 4 is a schematic diagram showing a temperature crack resistance measuring method according to an embodiment of the present invention.
5 is a flowchart illustrating a method of measuring a temperature crack resistance according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Although the present invention has been described with reference to the embodiments shown in the drawings, it is to be understood that the technical idea of the present invention and its essential structure and operation are not limited thereby.

1A and 1B are schematic perspective views of a temperature cracking resistance measuring apparatus 100 according to an embodiment of the present invention, respectively, and the concrete test body C is poured concrete into the temperature cracking resistance measuring apparatus 100 and It is a schematic perspective view showing the state in which the test body (C) is installed in the temperature crack resistance measuring apparatus (100). FIG. 2 is a schematic plan view of the apparatus for measuring temperature crack resistance 100 in the state shown in FIG. 1B.

In the present invention, there is provided an apparatus for measuring the resistance to temperature cracking occurring in concrete due to the heat of hydration of concrete, specifically, the temperature of the concrete test body (specifically the mass concrete to be tested) as an embodiment of the present invention A temperature cracking resistance measuring device 100 for measuring crack resistance is provided. As shown in FIGS. 1A, 1B and 2, the temperature cracking resistance measuring apparatus 100 of the present invention includes a first restraint body 11, a second restraint body 12, a first measuring unit 19, and It has the structure containing the 2nd measuring part 20. The temperature crack resistance measuring apparatus 100 is configured to quantitatively calculate the temperature crack resistance of the heat of hydration of the test body in a desired experimental environment.

Specifically, the first constrainer 11 includes a first surface 11a and a second surface 11b opposite thereto and has a closed figure shape. The second restraint body 12 includes a third face 12a and a fourth face 12b opposite thereto, and has a closed figure shape. Since the second constrainer 12 is larger than the first constrainer 11, when the second constrainer 12 is positioned to be spaced apart from the first constrainer 11 at a predetermined interval, the second constrainer 12 may be larger. Concrete is poured into the gap between the face 11b and the third face 12a to produce a concrete specimen. That is, the first restraint body 11 is disposed inside, and the second restraint body 12 is disposed outside, so that concrete is disposed between the first restraint body 11 and the second restraint body 12. It is poured and the concrete test body (C) is installed. In this structure, the first restraint 11 applies a restraining force when the concrete test body C contracts, and the second restraint 12 applies a restraining force when the concrete test body C expands.

In one embodiment of the invention shown in the figures, the first and second restraints 11, 12 are configured to have circular ring shapes with different diameters, wherein the circular ring shaped member has a plate having a thickness. It is formed by winding the member in a circular shape, and the inner and outer surfaces of the ring-shaped member constituting the first constraint 11 correspond to the first surface 11a and the second surface 11b, respectively. In addition, the inner surface and the outer surface of the ring-shaped member constituting the second constraint 12 correspond to the third surface 12a and the fourth surface 12b, respectively. However, in the present invention, the first and second constrainers 11 and 12 are not necessarily limited to such circular ring-shaped members, and may be embodied in various shapes of closed figures that can apply constraining force while measuring the strain of the concrete test body. have.

The first and second restraints 11 and 12 may be made of an alloy material having almost no volume change to heat since the restraint force is affected when the restraint volume changes due to the heat of concrete hydration. Preferably, the first and second constrainers 11 and 12 may be made of an alloy material having a thermal expansion coefficient of 1/10 ⁶ or less, for example, to minimize the volume change of the constrainer.

In the present invention, the dimensions of the first and second restraints 11 and 12 provided in the temperature crack resistance measuring apparatus 100 may be selected to have a desired range of restraint with respect to shrinkage and expansion of the concrete test specimen, for example. have. That is, the dimensions of the first constrainer 11 and the second constrainer 12 may be selected in the following manner, specifically as shown in FIGS. 1A, 1B and 2, the first and the first constraints. 2 When the restraints 11 and 12 are made of a circular ring member, the first face 11a and the second face 11b of the first and second restraints 11 and 12 at the center of the round ring member. , first to said third surface (12a) and a fourth surface (12b) R _1, the radius of each of R _2, R ₃ and R _4, wherein R _1, R ₂ and R ₃ are in accordance with equation 1 Can be selected.

In Equation 1, Es is an elastic modulus of the first and second restraints 11 and 12, E'c is an effective elastic modulus of the concrete test specimen C, and υ _c is a Poisson of the concrete test specimen C. Poisson's ratio, ν _s is the Poisson's ratio of the first and second constrainers 11, 12. Ψ _INT is the constraint on the shrinkage of the concrete specimen, that is, the shrinkage constraint.

Es and υ _s are intrinsic values determined according to the materials of the first and second restraints 11 and 12, and may have a constant value depending on the materials of the first and second restraints 11 and 12.

E'c and υ _c are the effective modulus of elasticity and Poisson's ratio of the concrete test specimen (C), respectively, and may be calculated and calculated theoretically when concrete materials are mixed, or may be calculated through a separate experiment after concrete materials are mixed.

According to an embodiment of the present invention, the temperature cracking resistance measuring apparatus 100 is designed to have a predetermined restraint, and accordingly, it is possible to measure the strain on the restraint having a predetermined restraint.

Therefore, the contraction restraint Ψ _INT which is the restraint for the shrinkage of the concrete test specimen and the expansion restraint Ψ _{OUT which} is the restraint for the expansion of the concrete test specimen are determined in advance to have a preset value, specifically, a value within a predetermined range. Can be.

Es, E'c, υ _s , υ _c and Ψ _INT may have a predetermined constant value depending on the material properties of the restraint body, the material properties of the test body, or the desired degree of restraint. Thus, Es, E'c, υ _s , υ _c and When a predetermined value is substituted for Ψ _INT , R ₁ , R _2, and R ₃ may be selected to any one of values satisfying [Equation 1].

On the other hand, R ₂ , R ₃ and R ₄ may be determined according to [Equation 2], respectively.

In Equation 2, Ψ _OUT is a constraint on expansion of the concrete test body, that is, an expansion constraint, and other symbols are the same as those described in Equation 1 above.

As explained earlier, Es, E'c, υ _s , υ _c and _OUT may have a predetermined predetermined value depending on the material properties of the restraint body, the material properties of the test body, or the desired degree of restraint. Therefore, by assigning a predetermined value to each variable, R ₂ , R _{3 as} one of the values satisfying [Equation 2] or [Equation 1] and [Equation 2] And R ₄ can be selected.

In this manner, the thicknesses of the first and second restraints (R ₂ minus R ₁ and R ₄ minus R ₃ ) and the spacing between the first and second restraints (R ₃ in R can be obtained regarding the dimensions obtained by subtracting the _second value), it is possible to design the apparatus and test sample accordingly.

According to one embodiment of the present invention, the difference between R ₃ and R ₂ may be selected to be at least three times the maximum dimension of the coarse aggregate of the concrete test body. If it is less than three times, the coarse aggregate applied to the concrete compounding will affect the measurement of the strain, making it difficult to obtain accurate data.

Meanwhile, according to an embodiment of the present invention, the first measuring unit 19 and the second measuring unit 20 may be disposed on the first surface 11a and the fourth surface 12b, respectively. Through the first measuring unit 19 and the second measuring unit 20, the strains of the first and second constraints 11 and 12 may be measured, respectively.

2, the first measuring unit 19 and the second measuring unit 20 may be disposed to face each other on the first surface 11a and the fourth surface 12b, respectively, and at the corresponding positions. It can be provided to measure the strain.

In addition, the first and second measurement units 19 and 20 may be configured as strain gages, and at least four may be attached along the first and fourth surfaces 11a and 4b, respectively. Can be. 1A and 1B, a plurality of first and second measuring units 19 and 20 are attached along the first surface 11a and the fourth surface 12b at equal intervals.

The first and second measurement units may be connected to the data recording and storage device 21 (refer to FIG. 4) to record and store the strain, but are not limited thereto. The first and second measurement units 19 and 20 may be used. ) Can be connected to the data logger.

Figure 3 shows a front view of the temperature crack resistance measuring apparatus 100 according to an embodiment of the present invention.

Referring to FIG. 3, the temperature crack resistance measuring apparatus 100 is disposed between the fixing plate 13 to which the first and second constraints are fixed, the fixing plate 13, and the first and second constraints. It may further include an elastic plate 15 to prevent the leakage of the test body.

The fixing plate 13 serves as a support plate that serves to support and fix the concrete test body C and the first and second restraints 11 and 12, and the concrete test body C and the first and second bodies. Constraints (11, 12) may be formed of a plate that is not curved so as not to be able to move freely, it is not necessarily limited to this may be made of wood or metal.

The elastic plate 15 is provided between the fixed plate 13 and the first and second restraints 11 and 12 to more securely support the concrete test body C and the first and second restraints 11 and 12. That is, it may be arranged in such a way that the elastic plate 15 is mounted on the fixing plate 13, and the first and second constraints 11 and 12 are mounted thereon.

In addition, the elastic plate 15 may have a thickness of 1.5 mm or more so as not to leak the concrete test body by close contact between the concrete test body (C) and the first and second constraints (11, 12) and the fixed plate (13). have. On the other hand, the elastic plate 15 may be formed of a synthetic resin, rubber, etc., but is not necessarily limited thereto.

In addition, according to an embodiment of the present invention between the first and second restraints (11, 12) and the elastic plate 15, more specifically, the lower end of the first and second restraints (11, 12) Additional waterproofing can be done to reliably prevent the outflow of the test specimen.

According to an embodiment of the present invention, an adhesion prevention layer (not shown) may be formed on the second surface and the third surface such that the concrete test body and the first and second constrainers are not attached. Although not necessarily limited thereto, the anti-sticking layer may be formed of a release agent or a lubricant such as vinyl.

In addition, the thickness of the anti-sticking layer may be mounted and applied to 0.1 mm or less, without necessarily being limited thereto, so as not to affect the dimensions of the first and second constraints.

Referring to FIG. 3, the first and second restraints 11 and 12 may have a predetermined height H to fill the cinder concrete specimen C, and the height H may be defined by the concrete test specimen. It may be formed to be at least three times the dimensions of the coarse aggregate. If the height (H) is less than three times because the strain is affected by the coarse aggregate. Preferably, the height H of the first and second restraints 11 and 12 may be manufactured to have a height of 152 mm or more in consideration of general coarse aggregate dimensions.

Figure 4 is a schematic diagram showing a temperature crack resistance measuring method according to an embodiment of the present invention.

Referring to FIG. 4, the apparatus for measuring temperature crack resistance 100 according to an embodiment of the present invention may be disposed in the test chamber 23. If the environment of the concrete specimen changes every time it can be difficult to quantitatively evaluate the temperature crack resistance. Therefore, in a state in which the temperature crack resistance measuring apparatus 100 is disposed in an environment in which the temperature and humidity are constantly controlled, such as an indoor laboratory environment, such as an indoor laboratory environment, to have an adiabatic temperature rise curve of a desired test object. By measuring the strain, the temperature cracking resistance of the concrete specimen can be quantitatively measured. In this case, quantitative evaluation is possible without being influenced by the surrounding environment.

According to an embodiment of the present invention, the first measuring unit 19 and the second measuring unit 20 may be connected to a data recording apparatus 21 for recording the measured strain, and the data recording apparatus 21 The data logger may be used, but is not necessarily limited thereto.

5 is a flowchart illustrating a method of measuring a temperature crack resistance according to an embodiment of the present invention.

Referring to FIG. 5, the method for measuring temperature cracking resistance according to an embodiment of the present invention includes a compound design step (S11), a first surface 11a, and a second surface 11b facing and closed of the concrete specimen. The first constrainer 11 having a figure shape, and a third surface spaced apart from the first constrainer 11 at a predetermined interval, and restraining the test body between the second constrained surface 11b. Installing a temperature cracking resistance measuring apparatus (100) comprising a second restraining member (12a) having a closed figure shape with a fourth surface (12b) opposite to it (S12) (see Fig. 1) And filling the test specimen with the temperature cracking resistance measuring apparatus and measuring the strain on the first surface 11a and the fourth surface 12b (S12), using the measured strain. Calculating the generation restraint stress (S14), and measuring the temperature cracking resistance using the calculated restraint stress. And a step (S15) to.

The first step is to mix design a concrete specimen with the desired properties. The elastic modulus, compressive strength and temperature cracking resistance of the test body can be theoretically calculated in the compound design step (S11) of the test body.

On the other hand, in the present invention, as described above, the test body may be tested in a state in which the condition is located under a condition having a desired heat insulation temperature rise curve. The calculation operation (S21) and the calculation operation (S22) of the adiabatic temperature rise curve for the test body are performed to form the test chamber 23 accordingly, and the temperature crack resistance measuring apparatus according to the present invention in the test chamber 23 ( 100) can be placed to perform the test. To this end, in the present invention, it is possible to experiment to measure the compressive strength and modulus of elasticity at intervals of 3 days, 7 days and 28 days for the physical properties of the mixed concrete test specimen. In addition, a single temperature rise curve of the test body can be obtained through the adiabatic temperature rise test of the test body.

The elastic modulus measured in this manner may be used to determine and manufacture the dimensions of the temperature crack resistance measuring apparatus 100 (S12).

On the other hand, by calculating the adiabatic temperature rise curve of the test specimen (S22), it is possible to determine the strain of the test specimen by determining the temperature change condition over time of the test chamber 23 in which the temperature crack resistance measuring device is present (S13). In addition, the generated strain of the test specimen may be calculated based on the strain measured in the strain gauge (S14). The compressive strength may be used to calculate the temperature cracking index together with the calculated generated restraint stress (S15).

After the compounding design step S11, a first restraint body 11 including a first face 11a and a second face 11b opposite thereto and having a closed figure shape, and the first restraint body 11. And a third surface 12a arranged to be spaced apart at predetermined intervals from the second surface 11b to restrain the concrete test body and the fourth surface 12b opposite thereto and having a closed figure shape. The temperature cracking resistance measuring apparatus 100 including the two restraints 12 is installed (S12).

According to an embodiment of the present invention, after installing the temperature cracking resistance measuring device providing a certain degree of restraint (S12), it is possible to measure the strain by filling the concrete test body, preferably the mass concrete test body to the temperature cracking resistance measuring device There is (S13).

According to one embodiment of the present invention, the temperature cracking resistance measuring apparatus measures the strain of the concrete specimen in a controlled laboratory environment, thereby enabling accurate comparison of the temperature cracking resistance without being affected by the surrounding environment.

According to one embodiment of the present invention, the concrete test body may be filled between the second and third surfaces of the first and second restraints in a state of being hardened, and at the height H of the first and second restraints. It can be charged by dividing it into two stages by half. In order to keep the packing density constant, it is possible to prevent the formation of voids or bubbles in the concrete specimen by using a compaction rod or a vibrator.

After the filling is completed, the concrete specimen can be covered with a vinyl cover, etc., to prevent the loss of moisture, thereby making the measurement more accurate.

According to one embodiment of the invention, the change in temperature rise of the concrete test body can be measured within the error range of less than 1 ㅀ at 10 minute intervals. Although not necessarily limited to this, the experiment may be performed for at least 7 days and up to 28 days, and the strain obtained from the first and second constraints may be continuously measured during the experiment.

 According to an embodiment of the present invention, after measuring the strain of the test specimen using the theoretical or experimentally obtained single temperature rise curve (S13), the generated binding stress of the test specimen may be calculated using the measured strain. There is (S14).

More specifically, in the first and second restraints having circular ring shapes having different diameters, the distance from the center of the circular ring to the first, second, third and fourth surfaces is R ₁ , R ₂ , R ₃ , and R ₄ , and the strain days ε _INT and ε _OUT measured on the first and fourth surfaces, and E _INT and E _OUT are elastic moduli of the first and second constraints, respectively. In this case, coefficients P _INT and P _OUT satisfying the following Equations 3 and 4 can be obtained.

That is, since R ₁ , R ₂ , R ₃ , and R ₄ are values set by preset constraints, and E _INT and E _OUT are intrinsic property values of the first and second constraints, respectively, the coefficients P _INT and P _OUT also has a constant value.

Substituting R ₁ , R ₂ , R ₃ , R ₄ , E _INT , E _OUT , P _INT, and P _OUT into Equation 5, the generated constraint stress σ _θ (r) according to the radial distance r is obtained. Can be calculated.

After calculating the generation restraint stress by the above method (S14), the temperature cracking index for each age is quantitatively calculated by calculating the temperature cracking index by dividing the compressive strength for each test specimen measured theoretically or experimentally by the generated generation restraint stress. It can be compared with (S15).

According to the temperature crack resistance measuring apparatus and the measuring method according to an embodiment of the present invention, it is possible to perform the demonstration experiment without administering a high cost as in the conventional large scale experiment evaluation. In addition, according to one embodiment of the present invention, it is possible to quantitatively compare the temperature crack resistance in a controlled environment without being affected by the external environment. And, according to an embodiment of the present invention, the user can design the temperature cracking resistance measuring apparatus to have a desired degree of restraint, and unlike the finite element analysis based on the design of the concrete structure, the concrete without considering the concrete structure The possibility of cracking can be predicted by empirical experiment in advance at the compounding stage.

11: first restraint
11a: first side
11b: second side
12: Second Restraint
12a: third side
12b: fourth side
13: fixed plate
15: elastic plate
100: temperature crack resistance measuring device

Claims (5)

A first restrainer comprising a first face and a second face opposite thereto and having a closed figure shape; And
The second constrainer is spaced apart from the first constrainer at a predetermined interval, and has a third surface constraining the concrete test body between the second constrained body and a fourth surface opposite thereto, the second constrained body having a closed figure shape. Including,
And a first measuring part and a second measuring part disposed on the first and fourth surfaces to measure strain of the test body.
The method of claim 1,
Wherein the first and second constrainers have a shape of circular rings having different diameters.
The method of claim 1,
A fixing plate to which the first and second restraints are fixed; And
And a resilient plate disposed between the fixed plate and the first and second restraints to prevent outflow of the test body.
The method of claim 1,
Temperature cracking resistance measuring apparatus, characterized in that the adhesion prevention layer is formed on the second surface and the third surface so that the test body and the first and second constraints are not attached.
Formulation design step of the concrete specimen;
A first restraint body including a first face and a second face opposite thereto and having a closed figure shape, and spaced apart from the first restraint at a predetermined interval, and restraining the test body between the second face and the second face; Providing a temperature cracking resistance measuring apparatus comprising a second constraining member having a third shape and a fourth surface opposite thereto and having a closed figure shape;
Filling the test body with the temperature crack resistance measuring apparatus and measuring strain on the first and fourth surfaces;
Calculating the generated constrained stress of the test body using the measured strain; And
And measuring temperature cracking resistance using the calculated generated constraint stress.

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