Method for determining micro features of a concrete interface transition zone

Abstract

The application provides a method for determining the micro characteristics of a concrete interface transition zone, comprising: randomly placing cement particles based on the particle size distribution parameters of the cement particles to obtain the particle size and position coordinates of the cement particles; obtaining the cement content and local water-cement ratio of each slice by using a slice processing method according to the particle size and position coordinates of the cement particles; obtaining a porosity distribution curve according to the cement content and local water-cement ratio; and dividing the boundary of the interface transition zone and determining the micro characteristics of the interface transition zone according to the porosity distribution curve. The application comprehensively considers various factors affecting the micro characteristics of the interface transition zone and can provide a theoretical basis for improving the macro mechanical properties of the interface transition zone of the concrete.

Description

Technical Field

[0001] This invention relates to the field of concrete technology, and more specifically, to a method for determining the microscopic characteristics of the transition zone at the concrete interface. Background Technology

[0002] The interfacial transition zone in concrete, located between cement paste and aggregate, is a key component affecting concrete performance. The thickness of this zone is typically between 20-50 μm, characterized by high porosity and low levels of unhydrated cement. Therefore, the interfacial transition zone easily becomes a convenient pathway for crack propagation and harmful ion transport in concrete, negatively impacting its macroscopic mechanical and durability properties. However, due to the extremely small size and opacity of the interfacial transition zone, experimentally obtaining its microscopic characteristics is very difficult. Therefore, numerical prediction of the microscopic characteristics of the concrete interfacial transition zone is crucial for analyzing concrete performance and service life.

[0003] A search revealed a Chinese patent with application number CN202110392899.6, which discloses a method for measuring the thickness of the transition zone at the interface of concrete. By analyzing the compressive deformation diagram of a concrete specimen, displacement data along the thickness direction of the interface transition zone is extracted to delineate the boundary of the transition zone, thereby calculating its thickness. However, this patent has the following problems: the sampling area width is limited, making it difficult to guarantee measurement accuracy; and it does not evaluate the microscopic characteristics of the interface transition zone, such as porosity and chloride ion diffusion coefficient.

[0004] Chinese patent application CN202310540822.8 discloses a sliding evaluation method for the microstructure of the interface transition zone in building materials. By performing tomographic imaging of samples in their original and contrast-enhanced states, and processing the scan results using image registration technology, the grayscale value changes at the same imaging location are obtained, and the corresponding local porosity and interface transition zone thickness are calculated. While the proposed method evaluates the thickness and porosity of the interface transition zone, this patent still has the following problems: the sub-region width is too large, resulting in strong dispersion of the measurement results; and the chloride ion diffusion coefficient, elastic modulus, and compressive strength of the interface transition zone are not evaluated.

[0005] Chinese patent application CN202310353369.X discloses a method for analyzing the thickness of the interface transition zone using backscattered scanning electron microscopy. By obtaining an image of the sample using a scanning electron microscope, binarization processing and a depth optimization algorithm are applied to calculate the aggregate edge. The porosity within a 5μm region along the aggregate edge is then statistically analyzed, and the interface transition zone boundary is defined to obtain the thickness and porosity of the interface transition zone. However, this patent has the following problems: the sample cross-section is randomly selected, which may overestimate the thickness of the interface transition zone; and the porosity characteristics of the interface transition zone are not combined with its performance. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the purpose of this invention is to provide a method for determining the microscopic characteristics of the transition zone at the concrete interface.

[0007] Existing methods for predicting the microscopic characteristics of the concrete interface transition zone mostly employ experimental techniques combining image analysis and strip segmentation, without proposing numerical prediction methods for these microscopic characteristics. Furthermore, existing experimental methods primarily target the thickness and porosity of the interface transition zone under specific mix proportions, and cannot be applied to predicting the chloride ion diffusion coefficient, elastic modulus, and compressive strength of concrete with various cement paste mix proportions and raw material types.

[0008] Therefore, in order to effectively predict the microscopic characteristics of the concrete interface transition zone and evaluate the macroscopic mechanical and durability properties of concrete, it is necessary to develop a method for predicting the microscopic characteristics of the concrete interface transition zone applicable to different cement paste ratios and raw material types, so as to provide theoretical guidance and technical reference for parametric modeling and engineering applications of concrete.

[0009] According to one aspect of the present invention, a method for determining the microscopic characteristics of the transition zone at a concrete interface is provided, the method comprising:

[0010] Cement particles were randomly released based on the particle size distribution parameters of cement particles to obtain the particle size and position coordinates of cement particles.

[0011] Based on the particle size and position coordinates of the cement particles, the cement content and local water-cement ratio of each slice are obtained by slicing.

[0012] Based on the cement content and local water-cement ratio, the porosity distribution curve was obtained;

[0013] Based on the porosity distribution curve, the boundary of the interface transition zone is delineated, and the microscopic characteristics of the interface transition zone are determined.

[0014] Optionally, cement particles are randomly released based on their particle size distribution parameters to obtain the particle size and location coordinates of the cement particles, including:

[0015] According to the experimental requirements, a concrete interface transition zone with length L, width W, and height H was set up to be analyzed. Based on the water-cement ratio m of the cement paste... w / c Density ρ of cement particles c The volume fraction of cement particles was determined by the influence coefficient s of the open boundary.

[0016] Generate random number w i , 0≤w i ≤1, and randomly generate the particle size D of the i-th cement particle. i D min ≤Di ≤D max Calculate the particle size distribution probability density value Among them, D max D is the maximum radius of the cement particles. min Let be the minimum radius of cement particles, and b and n be particle size distribution control parameters;

[0017] When w i ≤f N (D i When the particle size D is... i If effective, continue generating the next cement particle until the ratio of the total volume of all generated particles to the volume of the area to be analyzed in the interface transition zone reaches V. c ;

[0018] The coordinates of the center of each spherical cement particle are [x i ,y i ,z i ], sphere center coordinates and particle size D i The relationship is:

[0019]

[0020] Cement particles are added in descending order of size to create a non-overlapping spherical cement particle system.

[0021] Optionally, based on the particle size and position coordinates of the cement particles, a slicing method is used to obtain the cement content and local water-cement ratio of each slice, wherein: the cement content is expressed as the volume fraction of cement particles; and according to a preset slicing interval, starting from the slice x=0 and proceeding sequentially to the slice x=L, the cross-sectional area S of each cement particle on each slice is calculated. xi Within each slice, use the area fraction S c (x) replaces the volume fraction V of cement particles. c (x):

[0022]

[0023] Where x is the distance from the aggregate surface, W·H is the area of ​​the slice, and d is the preset slice spacing.

[0024] Optionally, based on the particle size and position coordinates of the cement particles, a slicing method is used to obtain the cement content and local water-cement ratio of each slice, wherein: the local water-cement ratio m at each slice w / c,x The calculation formula is:

[0025]

[0026] Where, ρ c This represents the density of cement particles.

[0027] Optionally, based on the cement content and local water-cement ratio, a porosity distribution curve is obtained, including:

[0028] The degree of hydration after a certain hydration time is obtained based on the local water-cement ratio at each slice.

[0029] Based on the degree of hydration at each slice, the volume fraction of each phase in the hydration system is obtained;

[0030] Based on the volume fraction of each phase, the porosity at each slice is obtained, thus yielding a porosity distribution curve.

[0031] Optionally, the degree of hydration after a certain hydration time is obtained based on the local water-cement ratio at each slice, wherein the formula for calculating the degree of hydration ξ(x,t) is:

[0032]

[0033] Where, ξ u,x τ represents the final degree of cement hydration related to the local water-cement ratio. T β and β represent parameters that indicate the influence of cement mineral composition on microstructure.

[0034] Optionally, the volume fraction of each phase in the hydration system is obtained based on the degree of hydration at each slice, wherein:

[0035] The volume fraction of the hydration products is:

[0036] The volume fraction of capillary pores is:

[0037] The volume fraction of the low-density CSH gel is:

[0038] The volume fraction of the high-density CSH gel is: f hdcsh (x,t)=0.8f h (x,t)-f ldcsh (x,t)

[0039] Among them, M r The mass ratio of low-density CSH gel to high-density CSH gel.

[0040] Optionally, the porosity at each slice is obtained based on the volume fraction of each phase, wherein: the porosity at each slice The calculation formula is:

[0041]

[0042] Optionally, based on the porosity distribution curve, the boundary of the interface transition zone is defined, and the microscopic characteristics of the interface transition zone are determined. The boundary of the interface transition zone is the aggregate surface and the location where the slope of the porosity curve begins to be less than -0.25%. The distance between the two boundaries is the thickness T of the interface transition zone. itz The average porosity within the interface transition zone is the porosity within the interface transition zone.

[0043] Optionally, the microscopic characteristics of the interface transition region are determined, including: calculating the chloride ion diffusion coefficient D of the interface transition region. itz Elastic modulus E itz and compressive strength σ itz :

[0044]

[0045]

[0046]

[0047] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0048] 1. This invention is based on the simulation of the formation process of the concrete interface transition zone. It can estimate the thickness and porosity of the interface transition zone according to the cement paste ratio and raw material information, and predict the chloride ion diffusion coefficient, elastic modulus and compressive strength of the interface transition zone. This method comprehensively considers various factors affecting the micro-characteristics of the interface transition zone, such as water-cement ratio, cement mineral composition, hydration time and cement particle size distribution. It can be used to analyze the mechanism of action of each influencing factor and provide a theoretical basis for improving the macroscopic mechanical properties of the concrete interface transition zone.

[0049] 2. The prediction method proposed in this invention is also applicable to analyzing the microscopic characteristics and macroscopic properties of cement paste matrix and cement mortar, thus providing necessary reference and guidance for the accurate modeling and analysis of concrete structures and the prediction of their service life. This method eliminates the need for experimental analysis, saving costs and contributing to the implementation of strategies such as smart construction and green building. Attached Figure Description

[0050] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0051] Figure 1 This is a schematic diagram of the process of generating and discharging cement particles in one embodiment of the present invention;

[0052] Figure 2 This refers to the area fraction of cement and the local water-cement ratio in one embodiment of the present invention;

[0053] Figure 3 This is a comparison of the porosity of the predicted results and experimental data in one embodiment of the present invention. Detailed Implementation

[0054] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0055] An embodiment of the present invention provides a method for determining the microscopic features of the transition zone at a concrete interface, comprising:

[0056] S1. Based on the particle size distribution parameters of cement particles, cement particles are randomly released to obtain the particle size and position coordinates of the cement particles.

[0057] S2. Based on the particle size and position coordinates of cement particles, the cement content and local water-cement ratio of each slice are obtained by slicing.

[0058] S3. Based on the cement content and local water-cement ratio, obtain the porosity distribution curve;

[0059] S4. Based on the porosity distribution curve, delineate the boundary of the interface transition zone and determine the microscopic characteristics of the interface transition zone.

[0060] Reference Figure 1 In some implementations, cement particles are randomly generated and released based on the particle size distribution parameters of the cement particles to obtain the particle size, quantity, and location coordinates of the cement particles, including:

[0061] According to the experimental requirements, a concrete interface transition zone with length L, width W, and height H was set up to be analyzed. Based on the water-cement ratio m of the cement paste... w / c Density ρ of cement particles c The volume fraction of cement particles was determined by the influence coefficient s of the open boundary.

[0062] Generate random number w i , 0≤w i ≤1, and randomly generate the particle size D of the i-th cement particle. i D min ≤D i ≤D max Calculate the particle size distribution probability density value

[0063] Among them, D max D is the maximum radius of the cement particles.min Let b be the minimum radius of the cement particles, and n be the particle size distribution control parameters; the particle size distribution parameters in step S1 refer to the four parameters D that control the particle size distribution. max D min b and n.

[0064] The particle size of cement particles is determined by a probability density function (particle size distribution probability density), while their quantity is controlled by the cement volume fraction and the volume of the interface transition zone to be analyzed. When w i ≤f N (D i When the particle size D is... i Effective. Continue generating the next cement particle until the ratio of the total volume of all generated particles to the volume of the area to be analyzed in the interface transition zone reaches V. c .

[0065] After determining the particle size and quantity of cement particles, the coordinates of the cement particles need to be randomly generated while simultaneously satisfying boundary conditions and non-overlapping conditions. The center coordinates of each spherical cement particle are [x...]. i ,y i ,z i ], sphere center coordinates and particle size D i The relationship satisfies the boundary conditions of formula (3):

[0066] Cement particles are added sequentially from largest to smallest according to their size, creating a non-overlapping spherical cement particle system. The particle size, quantity, and position coordinates of the cement particles in the concrete interface transition zone to be analyzed are determined according to... Figure 1 The process is as follows. To ensure that the cement particles do not overlap, when adding the cement particles, they are first rearranged according to their size, in descending order, generating random coordinates for the i-th particle, and then calculating the distance L between the i-th particle and the already added j-th particle. ij , j∈[1,i-1]. When all L ij ≥D i / 2+D j At / 2, the remaining cement particles are added sequentially to generate a system of non-overlapping spherical cement particles.

[0067] In some embodiments, in step S2, the cement content is expressed as the volume fraction of cement particles. Following a preset slice spacing d, for example, d = 0.1 μm, starting from slice x = 0 and proceeding sequentially to slice x = L, the cross-sectional area S of each cement particle on each slice is calculated. xi Within each slice, use the area fraction S c (x) replaces the volume fraction V of cement particles. c (x):

[0068] Where x is the distance from the aggregate surface, W·H is the area of ​​the slice, L is the length of the interface transition zone to be analyzed, and d is the preset slice spacing.

[0069] Furthermore, based on the cement area fraction S c (x) Determine the local water-cement ratio m at each slice. w / c,x The calculation formula is:

[0070]

[0071] Where, ρ c This represents the density of cement particles.

[0072] In some implementations, step S3 specifically includes:

[0073] S31. Based on the local water-cement ratio at each slice, the degree of hydration after a certain hydration time is obtained; specifically, the formula for calculating the degree of hydration ξ(x,t) is:

[0074]

[0075] Where, ξ u,x τ represents the final degree of cement hydration related to the local water-cement ratio. T β and β represent parameters that indicate the influence of cement mineral composition on microstructure, and are calculated according to the following formula:

[0076]

[0077]

[0078] Where χC3A, χC3S, and χSO3 represent the contents of C3A, C3S, and SO3 in the cement, respectively; Blaine represents the Blaine specific surface area of ​​the cement particles.

[0079] S32. Based on the degree of hydration at each slice, obtain the volume fraction of each phase in the hydration system;

[0080] Specifically, the volume fraction of the hydration products is:

[0081] The volume fraction of capillary pores is:

[0082] The volume fraction of the low-density CSH gel is:

[0083] The volume fraction of the high-density CSH gel is: f hdcsh (x,t)=0.8f h(x,t)-f ldcsh (x,t) (12)

[0085] Among them, M r The mass ratio of low-density CSH gel to high-density CSH gel is calculated using the following formula:

[0086] M r =0.528+ξ(x,t)·(3.017m w / c,x -1.347) (13)

[0087] S33. Based on the volume fraction of each phase, the porosity at each slice is obtained, thus yielding the porosity distribution curve.

[0088] Specifically, the porosity at each slice The calculation formula is:

[0089]

[0090] In some embodiments, in step S4, the boundary of the interface transition zone can be selected as the aggregate surface (x=0) and the location where the slope of the porosity curve begins to be less than -0.25%. The interface transition zone covers the area from the aggregate surface to the location where the slope of the porosity curve begins to be less than -0.25%, and the distance between the two boundaries is the thickness T of the interface transition zone. itz This allows for the quantitative determination of the thickness of the interface transition zone, and the average porosity of each slice within the interface transition zone is the porosity of the interface transition zone.

[0091] Chloride ion diffusion coefficient D in the interface transition region itz Elastic modulus E itz and compressive strength σ itz Porosity of the interface transition zone The relevant calculation formulas are as follows:

[0092]

[0093]

[0094]

[0095] The above embodiments of the present invention first employ random cement particle placement and continuous slicing to obtain the cement content and local water-cement ratio at a certain position from the aggregate surface. Based on the obtained cement content and water-cement ratio, the porosity curve of the interfacial transition zone after hydration for a certain period of time is calculated, ultimately yielding the thickness, porosity, chloride ion diffusion coefficient, elastic modulus, and compressive strength characteristics of the interfacial transition zone. This method comprehensively considers various factors affecting the microscopic characteristics of the interfacial transition zone, such as water-cement ratio, cement mineral composition, hydration time, and cement particle size distribution. It can be used to analyze the mechanism of action of each influencing factor, providing a theoretical basis for improving the macroscopic mechanical properties of the concrete interfacial transition zone.

[0096] In one specific embodiment, a method for predicting the microscopic characteristics of the transition zone at a concrete interface includes:

[0097] S1, based on cement particle density ρ c =3.11g / cm 3 The water-cement ratio m of cement paste w / c =0.35; The size of the area to be analyzed in the interface transition region is 150×150×150μm. 3 Cement particle size distribution parameter D max =100μm, D min =2μm, b=0.03, n=1.14; the open boundary influence coefficient is s=1.125. Based on these parameters, the particle system that meets the requirements is generated 100 times, and the average value of the cement content is taken to ensure the stability of the results.

[0098] S2. Based on the obtained information on the location and particle size of the cement particles, calculate the cement area fraction and local water-cement ratio at the slice location. The results are as follows: Figure 2 As shown. By Figure 2 It can be seen that both the cement area fraction and the local water-cement ratio exhibit gradient distribution characteristics. The smaller x is (the closer to the aggregate surface), the larger the water-cement ratio and the smaller the cement area fraction. This is consistent with the consistent understanding of the microscopic characteristics of the interface transition zone.

[0099] S3. Based on the obtained local area fraction and local water-cement ratio of the cement, calculate the porosity curve of the interfacial transition zone at t = 672 h, and compare the results with the experimental data obtained by backscatter scanning electron microscopy. The results are as follows: Figure 3 As shown. The information on the raw materials used in the experiment is the same as that given in S1. Figure 3 This demonstrates that the prediction method proposed in the embodiments of the present invention can obtain prediction results with high accuracy.

[0100] S4. Based on the obtained porosity curve of the concrete interface transition zone, the boundary of the interface transition zone is defined, and the microscopic characteristics such as the thickness of the interface transition zone and the cement paste matrix (the part of the area to be analyzed excluding the interface transition zone) are determined. The results are shown in Table 1.

[0101] Table 1 Comparison of microscopic parameters of the interface transition zone and cement slurry matrix obtained in this invention

[0102]

[0103] As shown in Table 1, compared with the cement paste matrix, the interfacial transition zone has a higher porosity, resulting in a larger chloride ion diffusion coefficient and lower elastic modulus and compressive strength. Furthermore, the higher porosity of the interfacial transition zone is the reason for its higher chloride ion diffusion coefficient, lower elastic modulus, and lower compressive strength. Therefore, the interfacial transition zone is a weak point in concrete, negatively impacting its macroscopic mechanical and durability properties. Based on the method of the above embodiments of the present invention, it can be found that using finer cement or a lower water-cement ratio can reduce the porosity of the interfacial transition zone. Therefore, in practical engineering, the cement paste mix ratio and raw material information can be reasonably adjusted to improve the performance of the interfacial transition zone, ensure the normal service of concrete structures, and provide necessary reference and guidance for accurate modeling analysis and service life prediction of concrete structures.

[0104] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention. The above preferred features can be used in any combination without conflict.

Claims

1. A method for determining the microscopic characteristics of the transition zone at a concrete interface, characterized in that, include: Cement particles were randomly released based on the particle size distribution parameters of cement particles to obtain the particle size and position coordinates of cement particles. Based on the particle size and position coordinates of the cement particles, the cement content and local water-cement ratio of each slice are obtained by slicing. Based on the cement content and local water-cement ratio, the porosity distribution curve was obtained; Based on the porosity distribution curve, the boundary of the interface transition zone is delineated, and the microscopic characteristics of the interface transition zone are determined.

2. The method for determining the microscopic characteristics of the concrete interface transition zone according to claim 1, characterized in that, Cement particles are randomly generated and released based on their particle size distribution parameters to obtain the particle size and location coordinates of the cement particles, including: According to the experimental requirements, a concrete interface transition zone with length L, width W, and height H was set up to be analyzed. Based on the water-cement ratio m of the cement paste... w / c Density ρ of cement particles c The volume fraction of cement particles was determined by the influence coefficient s of the open boundary. Generate random number w i , 0≤w i ≤1, and randomly generate the particle size D of the i-th cement particle. i D min ≤D i ≤D max Calculate the particle size distribution probability density value Among them, D max D is the maximum radius of the cement particles. min Let be the minimum radius of cement particles, and b and n be particle size distribution control parameters; When w i ≤f N (D i When the particle size D is... i If effective, continue generating the next cement particle until the ratio of the total volume of all generated particles to the volume of the area to be analyzed in the interface transition zone reaches V. c ; The coordinates of the center of each spherical cement particle are [x i ,y i ,z i ], sphere center coordinates and particle size D i The relationship is: Cement particles are added in descending order of size to create a non-overlapping spherical cement particle system.

3. The method for determining the microscopic characteristics of the concrete interface transition zone according to claim 2, characterized in that, Based on the particle size and position coordinates of the cement particles, a slicing method is used to obtain the cement content and local water-cement ratio of each slice, where the cement content is expressed as the volume fraction of cement particles. Following a preset slicing interval, starting from slice x = 0 and proceeding sequentially to slice x = L, the cross-sectional area S of each cement particle on each slice is calculated. xi Within each slice, use the area fraction S c (x) replaces the volume fraction V of cement particles. c (x): Where x is the distance from the aggregate surface, W·H is the area of ​​the slice, and d is the preset slice spacing.

4. The method for determining the microscopic characteristics of the concrete interface transition zone according to claim 3, characterized in that, Based on the particle size and location coordinates of the cement particles, a slicing method is used to obtain the cement content and local water-cement ratio of each slice, where: the local water-cement ratio m at each slice. w / c,x The calculation formula is: Where, ρ c This represents the density of cement particles.

5. The method for determining the microscopic characteristics of the concrete interface transition zone according to claim 4, characterized in that, Based on the cement content and local water-cement ratio, a porosity distribution curve is obtained, including: The degree of hydration after a certain hydration time is obtained based on the local water-cement ratio at each slice. Based on the degree of hydration at each slice, the volume fraction of each phase in the hydration system is obtained; Based on the volume fraction of each phase, the porosity at each slice is obtained, thus yielding a porosity distribution curve.

6. The method for determining the microscopic characteristics of the concrete interface transition zone according to claim 5, characterized in that, Based on the local water-cement ratio at each slice, the degree of hydration after a certain hydration time t is obtained, where: the formula for calculating the degree of hydration ξ(x,t) is: Where, ξ u,x τ represents the final degree of cement hydration related to the local water-cement ratio. T β and β represent parameters that indicate the influence of cement mineral composition on microstructure.

7. The method for determining the microscopic characteristics of the concrete interface transition zone according to claim 6, characterized in that, Based on the degree of hydration at each slice, the volume fraction of each phase in the hydration system is obtained, where: The volume fraction of the hydration products is: The volume fraction of capillary pores is: The volume fraction of the low-density CSH gel is: The volume fraction of the high-density CSH gel is: f hdcsh (x,t)=0.8f h (x,t)-f ldcsh (x,t) Among them, M r The mass ratio of low-density CSH gel to high-density CSH gel.

8. The method for determining the microscopic characteristics of the concrete interface transition zone according to claim 7, characterized in that, Based on the volume fraction of each phase, the porosity at each slice is obtained, wherein: the porosity at each slice The calculation formula is:

9. The method for determining the microscopic characteristics of the concrete interface transition zone according to claim 8, characterized in that, Based on the porosity distribution curve, the boundary of the interface transition zone is defined, and the microscopic characteristics of the interface transition zone are determined. Specifically, the boundary of the interface transition zone is the aggregate surface and the location where the slope of the porosity curve begins to be less than -0.25%. The distance between the two boundaries is the thickness T of the interface transition zone. itz The average porosity within the interface transition zone is the porosity of the interface transition zone.

10. The method for determining the microscopic characteristics of the concrete interface transition zone according to claim 9, characterized in that, Determine the microscopic characteristics of the interface transition region, including: calculating the chloride ion diffusion coefficient D of the interface transition region. itz Elastic modulus E itz and compressive strength σ itz :

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