Microscopic series and parallel homogenization model generation method for recycled concrete

Abstract

The invention provides a method for generating a mesoscopic series and parallel homogenization model of recycled concrete. The method mainly comprises the following steps: 1) obtaining the particle number of recycled concrete aggregate; 2) obtaining the thickness of an old mortar layer of the recycled concrete aggregate; 3) determining the distribution position of the recycled concrete aggregate, namely determining the putting position of each aggregate, and establishing a recycled concrete two-dimensional random aggregate distribution model; 4) performing automatic grid subdivision and unit attribute determination on the recycled concrete two-dimensional random aggregate distribution model; and 5) homogenizing the recycled concrete mesoscopic model. The method is reasonable in conception, the complex microstructure of the recycled concrete can be homogenized by adopting a series connection and parallel connection homogenization combination method, and therefore the model calculation efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a method for generating a microscopic series and parallel homogenization model of recycled concrete. Background Art

[0002] As the construction industry's requirements for resources and the environment continue to increase, recycled concrete has become a research hotspot due to its environmental advantages. However, the mesostructure of recycled concrete is complex, consisting of multiphase materials such as recycled aggregates, old mortar, and new mortar, which makes its mechanical properties have great uncertainty. Therefore, mesoscale mechanical analysis is of great significance for studying the performance of recycled concrete.

[0003] When conducting numerical analysis of recycled concrete, traditional mesoscopic models require detailed modeling of each phase of material in the mesoscopic structure, resulting in a large number of finite element units and low computational efficiency, especially in large-scale structural analysis, which shows a more obvious computational bottleneck. Since these models require a lot of computing resources and time, they are difficult to meet the needs of efficient analysis in engineering applications.

[0004] The traditional recycled concrete mesoscopic model has a large amount of calculation and low calculation efficiency when analyzing large-volume structures, and cannot meet the needs of efficient analysis in engineering applications. Therefore, a mesoscopic homogenization model and its corresponding analysis method that can improve calculation efficiency are urgently needed. Summary of the invention

[0005] In view of the technical problems existing in the above-mentioned background technology, the present invention proposes a method for generating a microscopic series and parallel homogenization model of recycled concrete. The conception is reasonable. By adopting a combination of series and parallel homogenization methods, the complex microscopic structure of recycled concrete can be homogenized, thereby greatly improving the model calculation efficiency.

[0006] In order to solve the above technical problems, the present invention provides a method for generating a microscopic series and parallel homogenization model of recycled concrete, which mainly includes the following steps:

[0007] 1) Obtain the number of particles of recycled concrete aggregate;

[0008] 2) Obtaining the thickness of the old mortar layer of recycled concrete aggregate;

[0009] 3) Determination of the distribution location of recycled concrete aggregate

[0010] Determine the placement location of each aggregate and establish a two-dimensional random aggregate distribution model for recycled concrete;

[0011] 4) Automatic mesh generation and unit attribute determination of the two-dimensional random aggregate distribution model of recycled concrete;

[0012] 5) Homogenization of recycled concrete mesoscopic model.

[0013] The method for generating a microscopic series and parallel homogenization model of recycled concrete, wherein the step 1) specifically includes the following steps:

[0014] According to the Walravin formula, the cumulative distribution probability of aggregate with particle size D<D0 is as follows:

[0015]

[0016] In the above formula (1), P k is the percentage of aggregate volume to total concrete volume; P c is the cumulative distribution probability of aggregate with particle size less than D0, D max is the maximum particle size of aggregate;

[0017] The formula for calculating the number of aggregate particles n with a particle size of D1<D<D2 in a recycled aggregate concrete specimen with a cross-sectional area of ​​A is as follows:

[0018] n=[P c (D<D2)-P c (D<D1)]×A / A i (2);

[0019] In the above formula (2), A i The diameter represents the area of ​​recycled aggregate; P c is the cumulative distribution probability of aggregate.

[0020] The method for generating a microscopic series and parallel homogenization model of recycled concrete, wherein the specific process of step 2) is as follows:

[0021] The volume percentage of old mortar is calculated by the density of natural aggregate, the density of mortar and their mass content percentage; the volume percentage of aggregate in concrete is basically equal to the area percentage of aggregate at a certain section, so the area ratio of old mortar to natural aggregate in recycled aggregate at a certain section can be calculated, and then the thickness of the old mortar layer in the recycled aggregate can be calculated:

[0022]

[0023] In the above formulas (3)-(4), V s ,V g Respectively represent the area occupied by old mortar and aggregate in the recycled aggregate; ρ s ,ρ g Represent the density of old mortar and aggregate respectively; m s ,m 总 Respectively represent the mass of old mortar and recycled aggregate; ω represents the mass content of old mortar; It represents the ratio of the old mortar area to the aggregate area;

[0024] The ratio of old mortar area to aggregate area The thickness of the mortar layer h is obtained:

[0025]

[0026] In the above formula (5), a represents the aggregate particle size.

[0027] The method for generating a microscopic series and parallel homogenization model of recycled concrete, wherein in step 3), a Monte Carlo method is used to generate a random number sequence, and then the center coordinates of the aggregate placement position are determined. The specific aggregate placement process is as follows:

[0028] 3.1) Determine the boundary range according to the size of the recycled aggregate concrete specimen and select the coordinate system;

[0029] 3.2) Obtain uniformly distributed random numbers R and E in the interval (0,1) using the Monte Carlo method;

[0030] 3.3) Calculate the center coordinates (x n ,y n ), as follows:

[0031]

[0032] In the above formula (6), b is the width of the cross section of the recycled aggregate concrete specimen; h is the length of the cross section of the recycled aggregate concrete specimen;

[0033] 3.4) Aggregates are placed in sequence according to the coordinates of the center of the aggregate circle. The aggregates placed are guaranteed to be within the size range of the recycled aggregate concrete specimen. There is no overlap between the aggregates placed later and the aggregates already placed. The distance between the centers of adjacent aggregate circles is greater than 1.05 times the sum of the radii of the two aggregates to ensure that there must be a cement mortar layer of a certain thickness between the two aggregates.

[0034] The method for generating a microscopic series and parallel homogenization model of recycled concrete, wherein the specific process of step 4) is: using a regular triangular meshing method, based on the cross-sectional size and meshing step size of the recycled aggregate concrete specimen, generating nodes with consistent density information, connecting the nodes to form plane triangular units, and then projecting the finite element mesh onto the two-dimensional random aggregate distribution model of recycled concrete generated in step 3); after the finite element mesh is projected, determining the unit type of the plane triangular unit by judging the relative position of the nodes of the plane triangular unit, and assigning unit attributes to each unit according to different unit types.

[0035] The method for generating a microscopic series and parallel homogenization model of recycled concrete, wherein the process of determining the relative position of the nodes of a plane triangular unit to determine its unit type is as follows: when all nodes of the plane triangular unit fall in the natural aggregate area, the unit is a natural aggregate unit; when all nodes fall in the old mortar area, the unit is an old mortar unit; when all nodes fall in the new mortar area, the unit is a new mortar unit; when some nodes are in the natural aggregate area and the rest fall in the old mortar area, the unit is an old bonding strip unit; when some nodes are in the old mortar area and the rest fall in the new mortar area, the unit is a new bonding strip unit; when unit nodes fall into the natural aggregate area, the old mortar area, and the new mortar area, the unit is also an old mortar unit.

[0036] The method for generating a microscopic series and parallel homogenization model of recycled concrete, wherein the specific process of step 5) is: using the random aggregate distribution model generated by the homogenization grid division step 3), according to the fraction of each phase material in each homogenization unit generated by the homogenization grid division, the series model and the parallel model are respectively used for homogenization equivalence, and the equivalent elastic modulus and Poisson's ratio of each homogenization unit are solved to obtain a microscopic homogenization model with uniformity and homogeneity inside the homogenization unit and different mechanical properties between units.

[0037] The method for generating the microscopic series and parallel homogenization model of the recycled concrete, wherein the specific solution process of the equivalent elastic modulus and Poisson's ratio of each homogenization unit is:

[0038] The parallel model is used to derive the equivalent elastic modulus of the microscopic homogenized unit at different damage stages. The materials of each phase in the homogenized unit satisfy the equal strain assumption. If the homogenized unit contains two phases of material, the effective elastic modulus of the parallel model can be given:

[0039]

[0040] Among them, c in the above formula (7) i =V i / V represents the volume fraction of the i-th phase; E i represents the elastic modulus of the i-th phase; K i represents the effective bulk modulus of the i-th phase; G i represents the shear modulus of the i-th phase; K v and G v is the value obtained using the parallel model;

[0041] For the special case where the two phases of material in the homogenized unit have the same Poisson's ratio, that is, E = E1c1 + E2c2 is obtained by ignoring the lateral deformation; for multiphase materials with n phases, there is

[0042] Assuming that each phase material in the homogenized unit satisfies the equal stress assumption, for the case of slight lateral deformation:

[0043]

[0044] For n-phase multiphase materials, we have

[0045] By adopting the above technical solution, the present invention has the following beneficial effects:

[0046] The method for generating a mesoscopic series and parallel homogenization model of recycled concrete of the present invention is well-conceived, and adopts a combination of series and parallel homogenization methods to simplify the complex mesoscopic structure of recycled concrete and significantly reduce the number of finite element units. Compared with the traditional mesoscopic model, the method of the present invention can greatly reduce the calculation time and resource consumption, and is particularly suitable for the numerical analysis of large-volume structures, providing an efficient calculation tool for engineering practice.

[0047] The present invention provides upper and lower limit estimates of material strength and elastic modulus respectively through parallel and series homogenization models. This dual estimation method improves the reliability of model prediction, provides a strong theoretical basis for engineering design and safety assessment, and can effectively solve the problems caused by uncertainty in material properties in engineering practice.

[0048] The method of the present invention is simple and easy to implement, and can be easily implemented in existing finite element analysis software, or used to develop autonomous and controllable high-efficiency computing software, thereby reducing the complexity of model construction and providing engineering technicians with a practical analysis method.

[0049] Through the model and method of the present invention, the performance of recycled concrete can be better understood and predicted, its application in construction projects can be promoted, the impact of construction waste on the environment can be reduced, and significant social and economic benefits can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 It is a flow chart of the method for generating the microscopic series and parallel homogenization model of recycled concrete of the present invention;

[0052] Figure 2It is a schematic diagram of a random aggregate distribution model of recycled concrete involved in the method for generating a mesoscopic series and parallel homogenization model of recycled concrete of the present invention;

[0053] Figure 3 It is a schematic diagram of a uniformly projected grid model involved in the method for generating a mesoscopic series and parallel homogenization model of recycled concrete according to the present invention;

[0054] Figure 4 A basic process diagram of mesoscopic homogenization involved in the method for generating a mesoscopic series and parallel homogenization model of recycled concrete according to the present invention;

[0055] Figure 5 Schematic diagram of the Voigt parallel model involved in the method for generating the microscopic series and parallel homogenization model of recycled concrete of the present invention;

[0056] Figure 6 It is a schematic diagram of the Reuss series model involved in the method for generating the micro-series and parallel homogenization model of recycled concrete of the present invention;

[0057] Figure 7 It is a schematic diagram of an L-type plate calculation model involved in the method for generating a microscopic series and parallel homogenization model of recycled concrete of the present invention;

[0058] Figure 8 It is a schematic diagram of the numerical calculation of the failure morphology of the L-type plate involved in the method for generating the microscopic series and parallel homogenization model of recycled concrete of the present invention;

[0059] Fig. 9 It is a force-displacement curve diagram of the loading points involved in the method for generating the microscopic series and parallel homogenization models of recycled concrete of the present invention. DETAILED DESCRIPTION

[0060] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] The present invention is further explained below in conjunction with specific implementation modes.

[0062] like Figure 1 As shown, this embodiment provides a method for generating a microscopic series and parallel homogenization model of recycled concrete, which mainly includes the following steps:

[0063] S100, obtain the number of particles of recycled concrete aggregate

[0064] According to the Walravin formula, the cumulative distribution probability of aggregate with particle size D<D0 is as follows:

[0065]

[0066] In the above formula (1), P k It is the percentage of aggregate volume to total concrete volume, generally 0.75; P c is the cumulative distribution probability of aggregate with particle size less than D0, D max is the maximum particle size of aggregate;

[0067] The formula for calculating the number of aggregate particles n with a particle size of D1<D<D2 in a recycled aggregate concrete specimen with a cross-sectional area of ​​A is as follows:

[0068] n=[P c (D<D2)-P c (D<D1)]×A / A i (2);

[0069] In the above formula (2), A i The diameter represents the area of ​​recycled aggregate; P c is the cumulative distribution probability of aggregate.

[0070] S200, obtain the thickness of the old mortar layer of recycled concrete aggregate

[0071] Through the density of natural aggregate (2600kg / m 3 ), density of mortar (2000kg / m 3 ) and its mass content percentage to calculate the volume percentage of old mortar. The volume percentage of aggregate in concrete is basically equal to the area percentage of aggregate at a certain section. From this, the area ratio of old mortar and natural aggregate in recycled aggregate at a certain section can be calculated, and then the thickness of the old mortar layer in the recycled aggregate can be calculated.

[0072]

[0073] Where V s ,V g Respectively represent the area occupied by old mortar and aggregate in recycled aggregate, ρ s ,ρ g Represent the density of old mortar and aggregate, m s ,m 总 Respectively represent the mass of old mortar and recycled aggregate, ω represents the mass content of old mortar, It represents the ratio of old mortar area to aggregate area.

[0074] The mortar layer thickness h is obtained from the area ratio.

[0075]

[0076] In the formula, a represents the aggregate particle size.

[0077] S300, Determination of the distribution location of recycled concrete aggregate

[0078] In order to better simulate the distribution of real aggregates, a set of random numbers needs to be generated to determine the placement of the aggregates. The present invention uses the Monte Carlo method to generate a random number sequence, and then determines the center coordinates of the aggregate placement position. The specific aggregate placement process is as follows:

[0079] S301, determining the boundary range according to the size of the recycled aggregate concrete specimen and selecting a coordinate system;

[0080] S302, obtaining uniformly distributed random numbers R and E in the interval (0,1) according to the Monte Carlo method;

[0081] S303, calculate the center coordinates (x n ,y n ), as follows:

[0082]

[0083] In the above formula (6), b is the width of the cross section of the recycled aggregate concrete specimen; h is the length of the cross section of the recycled aggregate concrete specimen;

[0084] S304. Aggregates are placed in sequence according to the coordinates of the center of the aggregates. The placed aggregates are guaranteed to be within the size range of the recycled aggregate concrete specimen, and there is no cross-overlap between the later placed aggregates and the already placed aggregates, and the distance between the centers of adjacent aggregates is greater than 1.05 times the sum of the two aggregate radii, so as to ensure that there must be a cement mortar layer of a certain thickness between the two aggregates.

[0085] The placement position of each aggregate is determined by the above method, and a two-dimensional random aggregate distribution model of recycled concrete at each level is established, such as Figure 2 Numerical specimens of recycled concrete are shown.

[0086] S400, Automatic mesh generation and unit attribute determination for a two-dimensional random aggregate distribution model of recycled concrete

[0087] A regular triangle meshing method is used. Based on the cross-sectional size and meshing step size of the recycled aggregate concrete specimen, nodes with consistent density information are automatically generated, and the nodes are connected to form plane triangle units. Then, the finite element mesh is projected onto the two-dimensional random aggregate distribution model of recycled concrete generated in step S300, as shown in FIG. Figure 3 shown.

[0088] After the finite element mesh is projected, the unit type is determined by judging the relative position of the nodes of the plane triangle unit. The specific process is: when all the nodes of the plane triangle unit fall in the natural aggregate area, this unit is a natural aggregate unit; when all the nodes fall in the old mortar area, this unit is an old mortar unit; when all the nodes fall in the new mortar area, this unit is a new mortar unit; when some nodes are in the natural aggregate area and the rest fall in the old mortar area, this unit is an old bonding strip unit; when some nodes are in the old mortar area and the rest fall in the new mortar area, this unit is a new bonding strip unit; when the unit nodes fall into the natural aggregate area, the old mortar area, and the new mortar area, this unit is also an old mortar unit.

[0089] According to different unit types, unit properties such as elastic modulus, Poisson's ratio and tensile strength are assigned to each unit.

[0090] S500, mesoscopic model homogenization

[0091] According to the fraction of each phase material in each homogenized unit generated by homogenized meshing (each homogenized unit contains one or more material phases, and the equivalent mechanical properties of the unit are calculated using the series or parallel model based on the volume fraction of these phases), the series model and the parallel model are used for homogenization and equivalence, and the equivalent elastic modulus and Poisson's ratio of each homogenized unit are solved, thereby obtaining a microscopic homogenized model with homogeneous homogeneity inside the homogenized unit and different mechanical properties between units, such as Figure 4 As shown; the specific solution process is as follows:

[0092] The Voigt parallel analysis model is used to derive the equivalent elastic modulus of the mesoscopic homogenized unit at different damage stages, such as Figure 5 As shown in the figure, each phase material in the homogenized unit satisfies the equal strain assumption;

[0093] If the homogenized element contains two phases of material, the effective elastic modulus of the parallel model can be given as:

[0094]

[0095] Among them, c in the above formula (7) i =V i / V represents the volume fraction of the i-th phase; E i represents the elastic modulus of the i-th phase; K i represents the effective bulk modulus of the i-th phase; G i represents the shear modulus of the i-th phase; K v and G v is the value obtained using the parallel model;

[0096] For the special case where the two phases of material in the homogenized unit have the same Poisson's ratio, that is, E = E1c1 + E2c2 is obtained by ignoring the lateral deformation; for multiphase materials with n phases, there is

[0097] like Figure 6 As shown in the figure, assuming that each phase material in the homogenized unit satisfies the equal stress assumption, for the case of slight lateral deformation:

[0098]

[0099] For n-phase multiphase materials, we have

[0100] Examples

[0101] Take the L-type plate test as an example. Figure 7 (a) The maximum size of recycled coarse aggregate is 31.5 mm, the minimum size is 5 mm, and the content of coarse aggregate larger than 5 mm is 46.6%. The content of aggregate attachment mortar is selected as 42%. The micro-unit size is 0.75 mm, and a two-dimensional finite element model is established. Figure 7 (b) The series homogenization model and the parallel homogenization model are respectively used to generate the series homogenization model and the parallel homogenization model, where the homogenization unit size is 1.5mm and 2.25mm respectively. The loading point adopts displacement stepwise static loading with a loading step of 0.001mm.

[0102] The numerical analysis results are as follows Figure 8-Figure 9 As shown, the simulation results show that the parallel homogenization model and the series homogenization model give the upper and lower limits of material strength and elastic modulus. This result is meaningful. It gives the maximum and minimum allowable values, which can solve some engineering problems.

[0103] The present invention has a reasonable concept. By adopting a combination method of series and parallel homogenization, the complex microstructure of recycled concrete can be homogenized, thereby greatly improving the calculation efficiency of the model.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for generating a microscopic series and parallel homogenization model of recycled concrete, characterized in that: The main steps include: 1) Obtain the number of particles of recycled concrete aggregate; 2) Obtaining the thickness of the old mortar layer of recycled concrete aggregate; 3) Determination of the distribution location of recycled concrete aggregate Determine the placement location of each aggregate and establish a two-dimensional random aggregate distribution model for recycled concrete; 4) Automatic mesh generation and unit attribute determination of the two-dimensional random aggregate distribution model of recycled concrete; 5) Homogenization of recycled concrete mesoscopic model.

2. The method for generating a microscopic series and parallel homogenization model of recycled concrete according to claim 1, characterized in that: The step 1) specifically comprises the following steps: According to the Walravin formula, the cumulative distribution probability of aggregate with particle size D<D0 is as follows: In the above formula (1), P k is the percentage of aggregate volume to total concrete volume; P c is the cumulative distribution probability of aggregate with particle size less than D0, D max is the maximum particle size of aggregate; The formula for calculating the number of aggregate particles n with a particle size of D1<D<D2 in a recycled aggregate concrete specimen with a cross-sectional area of ​​A is as follows: n=[P c (D<D2)-P c (D<D1)]×A / A i (2); In the above formula (2), A i The diameter represents the area of ​​recycled aggregate; P c is the cumulative distribution probability of aggregate.

3. The method for generating a microscopic series and parallel homogenization model of recycled concrete according to claim 1, characterized in that: The specific process of step 2) is as follows: The volume percentage of old mortar is calculated by the density of natural aggregate, the density of mortar and their mass content percentage; the volume percentage of aggregate in concrete is basically equal to the area percentage of aggregate at a certain section, so the area ratio of old mortar to natural aggregate in recycled aggregate at a certain section can be calculated, and then the thickness of the old mortar layer in the recycled aggregate can be calculated: In the above formulas (3)-(4), V s ,V g Respectively represent the area occupied by old mortar and aggregate in the recycled aggregate; ρ s ,ρ g Represent the density of old mortar and aggregate respectively; m s ,m 总 Respectively represent the mass of old mortar and recycled aggregate; ω represents the mass content of old mortar; It represents the ratio of the old mortar area to the aggregate area; The ratio of old mortar area to aggregate area The thickness of the mortar layer h is obtained: In the above formula (5), a represents the aggregate particle size.

4. The method for generating a microscopic series and parallel homogenization model of recycled concrete according to claim 1, characterized in that: In step 3), the Monte Carlo method is used to generate a random number sequence, and then the center coordinates of the aggregate placement position are determined. The specific aggregate placement process is as follows: 3.1) Determine the boundary range according to the size of the recycled aggregate concrete specimen and select the coordinate system; 3.2) Obtain uniformly distributed random numbers R and E in the interval (0,1) using the Monte Carlo method; 3.3) Calculate the center coordinates (x n ,y n ), as follows: In the above formula (6), b is the width of the cross section of the recycled aggregate concrete specimen; h is the length of the cross section of the recycled aggregate concrete specimen; 3.4) Aggregates are placed in sequence according to the coordinates of the center of the aggregate circle. The aggregates placed are guaranteed to be within the size range of the recycled aggregate concrete specimen. There is no overlap between the aggregates placed later and the aggregates already placed. The distance between the centers of adjacent aggregate circles is greater than 1.05 times the sum of the radii of the two aggregates to ensure that there must be a cement mortar layer of a certain thickness between the two aggregates.

5. The method for generating a microscopic series and parallel homogenization model of recycled concrete according to claim 1, characterized in that: The specific process of step 4) is as follows: using a regular triangular meshing method, based on the cross-sectional size and meshing step of the recycled aggregate concrete specimen, nodes with consistent density information are generated, the nodes are connected to form plane triangular units, and then the finite element mesh is projected onto the two-dimensional random aggregate distribution model of recycled concrete generated in step 3); after the finite element mesh is projected, the unit type of the plane triangular unit is determined by judging the relative position of the nodes of the plane triangular unit, and unit attributes are assigned to each unit according to different unit types.

6. The method for generating a microscopic series and parallel homogenization model of recycled concrete according to claim 5, characterized in that: The process of judging the relative positions of the nodes of the plane triangle unit to determine its unit type is as follows: when all the nodes of the plane triangle unit fall in the natural aggregate area, this unit is a natural aggregate unit; when all the nodes fall in the old mortar area, this unit is an old mortar unit; when all the nodes fall in the new mortar area, this unit is a new mortar unit; when some nodes are in the natural aggregate area and the rest fall in the old mortar area, this unit is an old bonding strip unit; when some nodes are in the old mortar area and the rest fall in the new mortar area, this unit is a new bonding strip unit; when some unit nodes fall in the natural aggregate area, some fall in the old mortar area, and some fall in the new mortar area, this unit is also an old mortar unit.

7. The method for generating a microscopic series and parallel homogenization model of recycled concrete according to claim 1, characterized in that: The specific process of step 5) is: using the random aggregate distribution model generated by the homogenization meshing step 3), according to the fraction of each phase material in each homogenized unit generated by the homogenization meshing, respectively adopting the series model and the parallel model for homogenization equivalence, and solving the equivalent elastic modulus and Poisson's ratio of each homogenized unit to obtain a microscopic homogenized model with uniformity and homogeneity inside the homogenized unit and different mechanical properties between units.

8. The method for generating a microscopic series and parallel homogenization model of recycled concrete according to claim 7, characterized in that: The specific solution process of the equivalent elastic modulus and Poisson's ratio of each homogenized unit is: The parallel model is used to derive the equivalent elastic modulus of the microscopic homogenized unit at different damage stages. The materials of each phase in the homogenized unit satisfy the equal strain assumption. If the homogenized unit contains two phases of material, the effective elastic modulus of the parallel model can be given: Among them, c in the above formula (7) i =V i / V represents the volume fraction of the i-th phase; E i represents the elastic modulus of the i-th phase; K i represents the effective bulk modulus of the i-th phase; G i represents the shear modulus of the i-th phase; K v and G v is the value obtained using the parallel model; For the special case where the two phase materials in the homogenized unit have the same Poisson's ratio, that is, E = E1c1 + E2c2 is obtained by ignoring the lateral deformation; for multiphase materials with n phases, there is Assuming that each phase material in the homogenized unit satisfies the equal stress assumption, for the case of slight lateral deformation: For n-phase multiphase materials, we have

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