Method for determining self-healing asphalt pavement induction medium type and mixing amount
Through formula calculations and induction heating tests, the type, size, and dosage of the induction medium in the upper and lower layers of self-healing asphalt pavement were determined. This solved the problems of time-consuming, labor-intensive, and error-prone processes in existing technologies, and achieved temperature uniformity and design accuracy in self-healing asphalt pavement, thus promoting its application in road maintenance engineering.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-28
- Publication Date
- 2026-03-27
AI Technical Summary
Existing technologies require extensive testing to determine the type and dosage of the sensing medium for self-healing asphalt pavements, which is time-consuming, labor-intensive, and prone to errors, affecting the accuracy and efficiency of the design scheme.
Through formula calculations and induction heating tests, the type, size, and dosage of the induction medium in the upper and lower layers of self-healing asphalt pavement were determined. The method of "coarse adjustment followed by fine adjustment" was adopted to reduce temperature differences, ensure temperature uniformity, and reduce the number of tests and errors.
It achieves uniform temperature distribution in self-healing asphalt pavements, significantly reduces the number and time of tests, improves the accuracy and efficiency of design schemes, and promotes the application of road maintenance projects.
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Figure CN116068020B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of asphalt pavement design, and particularly relates to a method for determining the type and amount of inductive medium of self-healing asphalt pavement. TECHNICAL BACKGROUND
[0002] Vehicle overload and overloading on the road can cause road damage such as cracks and deformation. Self-healing asphalt pavement can achieve self-repair of the road, saving manpower and material resources and not affecting the normal use of the road. The existing self-healing asphalt pavement has the phenomenon of uneven temperature distribution in actual application, causing different self-healing conditions at different depths of the road and affecting the road performance.
[0003] To solve the above phenomenon, some scholars propose a new type of self-healing asphalt pavement, which has two layers, and realizes road self-healing through electromagnetic induction heating. By adjusting the type and amount of inductive medium of each layer, the influence of the change of magnetic field strength at different depths on heat generation is eliminated, and the temperature is uniformly distributed at different depths during inductive heating. It has great use value for future road maintenance engineering.
[0004] However, the existing design method for determining the type, size and amount of inductive medium of the new type of self-healing asphalt pavement needs a large number of tests to obtain the optimal scheme, which not only consumes time and effort, but also inevitably produces errors in the test, affecting the accuracy of the design scheme. SUMMARY
[0005] In view of the deficiencies of the prior art, the present application provides a method for determining the type and amount of inductive medium of self-healing asphalt pavement, which determines the type, size and amount of inductive medium of the upper and lower layers of self-healing asphalt pavement through a formula, improves the accuracy of the design scheme, and significantly reduces the number of tests.
[0006] To achieve the above purpose, the technical scheme of the present application is implemented as follows:
[0007] A method for determining the type and amount of inductive medium of self-healing asphalt pavement, the self-healing asphalt pavement comprising two layers of upper and lower layers with the same thickness, each layer containing inductive medium of different types and amounts, the method for determining the type and amount of inductive medium comprising the following steps:
[0008] S1, preparing asphalt pavement test pieces mixed with inductive medium in the upper and lower layers, wherein the volume fraction of inductive medium in each layer is 0.1% to 10%, and the volume fraction of inductive medium in the upper layer is greater than that in the lower layer; the inductive medium of the asphalt pavement test piece, wherein the absolute permeability of the inductive medium is μ0, and the resistivity of the inductive medium is ρ0; the absolute permeability of the inductive medium is μ0, and the resistivity of the inductive medium is ρ0;
[0009] S2, the asphalt pavement specimen in S1 is subjected to induction heating test, considering that the surface of the specimen is in contact with air and heat loss will occur, the specimen is vertically cut open, the temperatures T1 and T2 at the middle lines of the upper and lower layers of the specimen cross section are recorded respectively, the initial temperature of the asphalt pavement specimen is recorded as T0, the temperature changes ΔT1=T1-T0 and ΔT2=T2-T0 of the upper and lower layers of the specimen are calculated, and the average value thereof is calculated
[0010] S3, according to the temperature changes ΔT1 and ΔT2 of the upper and lower layers of the asphalt pavement specimen in S2, and in combination with the target induction heating efficiency in the heating process, the types of the induction medium of the upper and lower layers of the self-healing asphalt pavement specimen are determined respectively;
[0011] S4, according to the types of the induction medium of the upper and lower layers of the self-healing asphalt pavement specimen determined in S3, the optimal sizes of the induction medium of each layer are calculated, and the self-healing asphalt pavement specimen with the corresponding types and sizes of the induction medium is prepared;
[0012] S5, the self-healing asphalt pavement specimen in S4 is subjected to induction heating test, considering that the surface of the specimen is in contact with air and heat loss will occur, the specimen is vertically cut open, the temperatures T1' and T2' at the middle lines of the upper and lower layers of the specimen cross section are recorded respectively, the initial temperature of the asphalt pavement specimen is recorded as T0, the temperature changes ΔT1'=T1'-T0 and ΔT2'=T2'-T0 of the upper and lower layers of the specimen are calculated, and the average value thereof is calculated
[0013] S6, according to the temperature changes ΔT1' and ΔT2' of the upper and lower layers of the self-healing asphalt pavement specimen in S5, the dosages of the induction medium of the upper and lower layers of the self-healing asphalt pavement specimen are determined respectively, and the self-healing asphalt pavement specimen with the corresponding dosages is prepared;
[0014] S7, the types, sizes and dosages of the induction medium of the upper and lower layers of the self-healing asphalt pavement specimen in step S6 are determined as the optimal design scheme.
[0015] Preferably, according to the above scheme, in step S3, the determination method of the type of the induction medium comprises the following steps:
[0016] ① the temperature changes ΔT1 and ΔT2 of the upper and lower layers of the self-healing asphalt pavement specimen are adjusted to the average value thereof The absolute magnetic permeability and resistivity of the selected induction medium should satisfy the following formula:
[0017]
[0018] Wherein, i is the layer of the self-healing asphalt pavement specimen, i=1 represents the upper layer, i=2 represents the lower layer, μ i ' is the absolute magnetic permeability of the induction medium of the i-th layer of the specimen after adjustment, ρi ' is the resistivity of the i-th layer of the test piece after adjusting the type of the induction medium, m i ' is the specific heat capacity of the i-th layer of the test piece in S1, c i ' is the specific heat capacity of the i-th layer of the test piece after adjusting the type of the induction medium, m i ' is the mass of the i-th layer of the test piece in S1, m i ' is the mass of the i-th layer of the test piece after adjusting the type of the induction medium.
[0019] ②The induction medium of the upper and lower layers of the self-healing asphalt pavement test piece meets the induction heating efficiency requirement, and the medium range that meets the uniformity of the pavement test piece is reduced. The absolute permeability and resistivity of the selected induction medium should meet:
[0020]
[0021] Wherein, η is the target induction heating efficiency, ρ c is the resistivity of the induction heating coil, and μ0 is the vacuum permeability.
[0022] ③According to the requirements in steps ① and ②, the values of the conductivity and absolute permeability of the induction medium that meet the temperature uniformity of the upper and lower layers of the self-healing asphalt pavement test piece and the induction heating efficiency are obtained, and the type of the induction medium of the upper and lower layers of the test piece is determined.
[0023] Preferably, according to the above scheme, in step S4, the formula for determining the optimal size of the induction medium is:
[0024]
[0025] Wherein, δ is the optimal radius of the induction medium particles, and f is the induction heating frequency.
[0026] Preferably, according to the above scheme, in step S6, the determination method of the induction medium content includes the following steps:
[0027] ①In order to make the temperature changes ΔT1' and ΔT2' of the upper and lower layers of the self-healing asphalt pavement test piece adjust to their average values The calculation formula of the induction medium content of the upper and lower layers of the self-healing asphalt pavement test piece is:
[0028]
[0029] Wherein, c i ' is the specific heat capacity of the i-th layer of the test piece in S4, c i ' is the specific heat capacity of the i-th layer of the test piece in S4, c i ' is the mass of the i-th layer of the test piece in S4, m i ' is the mass of the i-th layer of the test piece in S4, m
[0030] If the calculated amount of the induction medium in the upper and lower layers of the self-healing asphalt pavement test piece is less than or equal to the calculated amount of the induction medium in the upper and lower layers of the formula 1 is the optimal amount of the induction medium to be solved;
[0031] If the calculated amount of any layer is greater than the amount of the induction medium in the layer is adjusted to and the temperature change of the layer after induction heating is calculated when the amount of the induction medium in the layer is The calculation formula is:
[0032]
[0033] According to the temperature change of the layer the amount of the induction medium in another layer of the self-healing asphalt pavement test piece is determined The calculation formula is:
[0034]
[0035] and and are the optimal amounts of the induction medium in the corresponding layers of the self-healing asphalt pavement test piece, respectively.
[0036] Preferably, according to the above scheme, the specific heat capacity c of each layer of the test piece is:
[0037]
[0038] wherein k is the number of types of materials in the test piece, c j is the specific heat capacity of the jth material, and λ j is the mass fraction of the jth material.
[0039] Preferably, according to the above scheme, the mass m of each layer of the test piece is:
[0040]
[0041] wherein k is the number of types of materials in the test piece, m j is the density of the jth material, and λ j is the mass fraction of the jth material.
[0042] Preferably, according to the above scheme, in the step S1, is the maximum amount of the induction medium that does not affect the pavement performance (high-temperature stability, low-temperature crack resistance, and fatigue resistance).
[0043] The application provides a method for determining the type and content of an induction medium of a self-healing asphalt pavement.
[0044] (1) The application provides a method for determining the type and content of an induction medium of a self-healing asphalt pavement, which is characterized in that: according to the different influence degrees of the type and content of the induction medium on the heat generation of the induction medium, the temperature difference between the upper layer and the lower layer of the self-healing asphalt pavement test piece is initially reduced by adjusting the type of the induction medium according to the principle of "rough adjustment first and then fine adjustment", and the optimal size of the induction medium in each layer is calculated, and then the temperature difference between the upper layer and the lower layer of the self-healing asphalt pavement test piece tends to zero by adjusting the content of the induction medium, so that the optimal design scheme of the type, size and content of the induction medium of the self-healing asphalt pavement can be quickly and accurately determined.
[0045] (2) The application provides a method for determining the type and content of an induction medium of a self-healing asphalt pavement, which is characterized in that: the type and content of the induction medium of the self-healing asphalt pavement test piece are determined through an induction heating test and a calculation formula, so that the uniform distribution of the temperature of the self-healing asphalt pavement at different depths is realized, and compared with the traditional method, the optimal scheme can be obtained only by two tests, the test times are significantly reduced, and the time and manpower required for obtaining the optimal scheme are effectively reduced.
[0046] (3) The application provides a method for determining the type and content of an induction medium of a self-healing asphalt pavement, which is characterized in that: compared with the traditional method, the method only needs to perform two tests, reduces the inevitable errors caused by the tests, determines the type and content of the induction medium of the self-healing asphalt pavement through a calculation formula, and guarantees the accuracy of the design scheme.
[0047] (4) The application provides a method for determining the type and content of an induction medium of a self-healing asphalt pavement, which is characterized in that: the average value of the temperature change of the upper layer and the lower layer of the self-healing asphalt pavement test piece after the induction heating test is taken as an adjustment index, so that the content of the induction medium of the upper layer and the lower layer of the self-healing asphalt pavement can be guaranteed to be moderate.
[0048] (5) The application provides a method for determining the type and content of an induction medium of a self-healing asphalt pavement, which is of great significance to improve the use performance of the self-healing asphalt pavement and is beneficial to promoting the application of the self-healing asphalt pavement in road maintenance engineering. ACCURACY:
[0049] Figure 1 : The flow chart of the method for determining the type and content of an induction medium of a self-healing asphalt pavement.
[0050] Figure 2 : The schematic view of the middle line of the test piece section. DETAILED DESCRIPTION:
[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0052] Example:
[0053] A method for determining the type and dosage of induction medium for self-healing asphalt pavement includes the following steps:
[0054] In this embodiment, AC-13 asphalt concrete is selected as the material for self-healing asphalt pavement. Its material composition and proportions are: crushed stone: stone chips: sand: mineral powder = 36%: 31%: 25%: 8%, asphalt-aggregate ratio = 5%. The densities of each material are: crushed stone 1400 kg / m³. 3 1500 kg / m³ of stone chips 3 14000 kg / m³ of sand 3 2800 kg / m³ of mineral powder 3 1000 kg / m³ of asphalt 3 The specific heat capacities of each material are as follows: crushed stone 0.92 kJ / (kg·℃), stone chips 0.92 kJ / (kg·℃), sand 0.92 kJ / (kg·℃), mineral powder 1.67 kJ / (kg·℃), and asphalt 1.67 kJ / (kg·℃).
[0055] The density of the added induction medium, scrap steel, is 2300 kg / m³. 3 Its specific heat capacity is 0.46 kJ / (kg·℃).
[0056] In this embodiment, the asphalt pavement test specimen type selected is the Marshall specimen.
[0057] Given the mix proportions of AC-13 asphalt concrete and the volume fraction and density of waste steel scrap, calculate the mass fraction of each material in the asphalt pavement test specimen, and then apply the formula... and The mass and specific heat capacity of the asphalt pavement test specimens were calculated respectively.
[0058] S1. Prepare asphalt pavement test specimens with both upper and lower layers containing 8% by volume of waste steel scrap. The absolute magnetic permeability of the waste steel scrap is μ0 = 17.6 × 10⁻⁶. -6 (H / m), resistivity ρ0=1.5×10 -6 (Ω / m), based on experimental tests, the highest induction medium dosage that satisfies the requirements of high-temperature stability, low-temperature crack resistance, and fatigue resistance of road surfaces is taken. To ensure the smooth implementation of the example, the following is taken: δ0 = 4mm;
[0059] S2, the asphalt pavement test piece in S1 is subjected to induction heating test, the power and frequency of induction heating are 3 kW and 35 kHz respectively, the initial temperature T0 is 12℃, the heating time is 10 min, considering that the surface of the test piece is in contact with air and heat loss will occur, after the heating is completed, the test piece is vertically cut along the diameter, the temperature T1 = 66.6℃ at the middle line of the upper layer of the test piece section, the temperature T2 = 26.2℃ at the middle line of the lower layer, the temperature difference of the upper and lower layers of the test piece is ΔT1 = T1-T0 = 54.6℃, ΔT2 = T2-T0 = 14.2℃, and the average value is
[0060] S3, according to the temperature changes ΔT1 and ΔT2 of the upper and lower layers of the asphalt pavement test piece in S2, the types of induction medium of the upper and lower layers of the self-healing asphalt pavement test piece are determined.
[0061] According to Faraday's law and Joule's law, the relationship between the heat generated in the upper and lower layers of the self-healing asphalt pavement test piece and the temperature is:
[0062]
[0063] wherein i is the layer of the asphalt pavement test piece, i = 1 represents the upper layer, i = 2 represents the lower layer, f is the frequency of the magnetic field, H i is the magnetic field strength of the i-th layer, A0 is the area surrounded by the initial induction medium, t is the induction heating time, R0 is the resistance of the initial induction medium, μ0 is the absolute magnetic permeability of the initial induction medium, c i is the specific heat capacity of the i-th layer of the test piece in S1, m i is the mass of the i-th layer of the test piece in S1.
[0064] Average temperature The relationship between the heat generated in the upper and lower layers of the lower self-healing asphalt pavement test piece and the temperature is:
[0065]
[0066] wherein R i ' is the resistance of the i-th layer of the induction medium of the obtained test piece after adjustment, μ i ' is the absolute magnetic permeability of the i-th layer of the induction medium of the obtained test piece after adjustment, c i ' is the specific heat capacity of the i-th layer of the test piece after adjustment of the type of induction medium, m i ' is the mass of the i-th layer of the test piece after adjustment of the type of induction medium.
[0067] It is assumed that the test piece is subjected to induction heating under the same conditions as the test piece in S1 after adjustment of the type of induction medium, therefore the same f, H i, t, because the inductive medium content is unchanged before and after adjustment, so the same layer of the test piece before and after adjustment has the same A0.
[0068] Q i and Q i Compared with Q, the equal parameters are removed, and the equation is obtained:
[0069]
[0070] Wherein, l is the thickness of the test piece, and s is the cross-sectional area of the test piece.
[0071] The relationship between the resistance and the resistivity is combined:
[0072]
[0073] Wherein, p is the resistivity of the inductive medium.
[0074] The equation is obtained:
[0075]
[0076] Therefore, the relationship between the resistivity and the relative permeability of the inductive medium in the upper and lower layers of the self-healing asphalt pavement test piece is:
[0077]
[0078] The method for determining the type of inductive medium of the self-healing asphalt pavement test piece comprises the following steps:
[0079] ①Adjust the temperature changes ΔT1 and ΔT2 of the upper and lower layers of the self-healing asphalt pavement test piece to their average values The absolute permeability and resistivity of the selected inductive medium should satisfy:
[0080]
[0081] Wherein, p i ' is the resistivity of the inductive medium of the i-th layer of the test piece after adjustment.
[0082] ②The inductive medium of the upper and lower layers of the self-healing asphalt pavement test piece should satisfy the inductive heating efficiency requirement, and the medium range satisfying the uniformity of the pavement test piece should be reduced, and the absolute permeability and resistivity of the selected inductive medium should satisfy:
[0083]
[0084] Wherein, p c is the resistivity of the inductive heating coil, and the commonly used inductive heating coil is copper pipe, and its resistivity p c = 1.7 × 10 -8(Ω / m), η is the target induction heating efficiency, and the target induction heating efficiency η is ≥ 80%.
[0085] ③According to the requirements in steps ① and ②, the values of the conductivity and the absolute permeability of the induction medium that meet the uniformity of the upper and lower layers of the self-healing asphalt pavement sample and the induction heating efficiency are obtained, and the types of the induction medium of the upper and lower layers of the sample are determined.
[0086] Common induction medium types suitable for the upper layer of the self-healing asphalt pavement sample are shown in Table 1.
[0087] Table 1: Medium types of the upper layer of the sample
[0088]
[0089] Common induction medium types suitable for the lower layer of the self-healing asphalt pavement sample are shown in Table 2.
[0090] Table 2: Medium types of the lower layer of the sample
[0091]
[0092] In practical applications, in order to reduce economic costs, induction medium with relatively low price is selected as the material of the self-healing asphalt pavement, therefore, we select waste low-carbon steel as the upper layer induction heating medium of the self-healing asphalt pavement, and waste cast iron chips as the lower layer induction heating medium of the asphalt pavement.
[0093] S4, according to the determination of the upper and lower layer induction medium types of the asphalt pavement sample in S3, the optimal size of different types of induction medium is calculated, and the self-healing asphalt pavement sample with corresponding induction medium types and sizes is prepared.
[0094] The calculation formula of the optimal size of the induction medium is:
[0095]
[0096] wherein, δ is the optimal radius of the induction medium particles, and f is the induction heating frequency.
[0097] According to the formula, the particle radius of the waste low-carbon steel in the upper layer of the self-healing asphalt pavement sample is 3.39 mm, and the particle radius of the waste cast steel chips in the lower layer of the self-healing asphalt pavement sample is 2.23 mm.
[0098] S5, the self-healing asphalt pavement test piece in S4 is subjected to induction heating test, the power and frequency of induction heating are 3 kW and 35 kHz respectively, the initial temperature T0 is 12℃, the heating time is 10 min, considering that the surface of the test piece is in contact with air and heat loss will occur, after the heating is completed, the test piece is vertically cut along the diameter, the temperature T1' at the middle line of the upper layer of the test piece is recorded, which is 49.7℃, the temperature T2' at the middle line of the lower layer of the test piece is 42.3℃, the temperature difference of the upper and lower layers of the test piece is ΔT1' = T1'-T0' = 37.7℃ and ΔT2' = T2'-T0' = 30.3℃ respectively, and the average value is
[0099] S6, according to the temperature changes ΔT1' and ΔT2' of the upper and lower layers of the self-healing asphalt pavement test piece in S5, the induction medium contents of the upper and lower layers of the self-healing asphalt pavement test piece are determined respectively, and the corresponding self-healing asphalt pavement test pieces are prepared;
[0100] According to the induction medium types of the upper and lower layers of the self-healing asphalt pavement test piece determined in step S3, it can be known that the relationship between the heat generated by the upper and lower layers of the self-healing asphalt pavement test piece and the temperature is:
[0101]
[0102] The relationship between the heat generated by the upper and lower layers of the self-healing asphalt pavement test piece and the temperature is:
[0103]
[0104] Wherein, c i is the specific heat capacity of the i-th layer of the test piece obtained after adjusting the induction medium content, m i is the mass of the i-th layer of the test piece obtained after adjusting the induction medium content, A i is the area surrounded by the induction medium of the i-th layer of the test piece obtained after adjustment.
[0105] It is assumed that the test piece is subjected to induction heating under the same conditions as the test piece in S1 after adjusting the induction medium content, so the same f, H i Because the types of induction medium do not change before and after adjustment, the same μ i ', ρ i ' of the same layer of the test piece before and after adjustment.
[0106] Q i " is compared with Q i ", and the equal parameters are eliminated to obtain the equation:
[0107]
[0108] The relationship between the induction medium surrounding area and the induction medium content is combined:
[0109]
[0110] wherein, is the induction medium content, x is the loss coefficient, A s is the cross-sectional area of the self-healing asphalt pavement test piece.
[0111] The calculation formula of the induction medium content of the upper and lower layers of the self-healing asphalt pavement test piece is:
[0112]
[0113] The method for determining the induction medium content of the self-healing asphalt pavement test piece comprises the following steps:
[0114] ① In order to make the temperature changes ΔT1' and ΔT2' of the upper and lower layers of the self-healing asphalt pavement test piece adjust to their average values The calculation formula of the induction medium content of the upper and lower layers of the self-healing asphalt pavement test piece is:
[0115]
[0116] wherein, c i ' is the specific heat capacity of the i-th layer of the S4 test piece, c i " is the specific heat capacity of the i-th layer of the test piece obtained after adjusting the induction medium content, m i ' is the mass of the i-th layer of the S4 test piece, m i " is the mass of the i-th layer of the test piece obtained after adjusting the induction medium content;
[0117] According to the formula, the content of the upper layer of the self-healing asphalt pavement test piece is the content of the lower layer of the self-healing asphalt pavement test piece is
[0118] ② According to the formula in ①, if the calculated content of the induction medium of the upper and lower layers of the self-healing asphalt pavement test piece is less than or equal to then the content of the induction medium of the upper and lower layers calculated by the formula in ① is the optimal content of the induction medium;
[0119] ③ If the calculated content of any layer is greater than then the content of the layer is adjusted to and the temperature change of the layer after induction heating when the content of the induction medium of the layer is The calculation formula of the temperature change of the layer after induction heating when the content of the induction medium of the layer is
[0120]
[0121] According to the temperature change of the layer Determining the mixing amount of another layer of inductive medium of self-healing asphalt pavement test piece The calculation formula is:
[0122]
[0123] Then And The optimal mixing amount of the corresponding layer of inductive medium of the self-healing asphalt pavement test piece is respectively.
[0124] Because the mixing amount of the upper layer of inductive medium of the test piece, waste low-carbon steel, calculated in ① is Therefore, the mixing amount of waste low-carbon steel is taken as According to the formula, the mixing amount of the lower layer of inductive medium of the test piece, waste cast iron chips, is calculated as
[0125] S7, the corresponding upper and lower layer of inductive medium of the self-healing asphalt pavement test piece in step S6 is waste low-carbon steel and waste cast iron chips, the thickness is 3.39 mm and 2.23 mm respectively, and the mixing amount is 9% and 7.03% respectively, and the corresponding scheme is the optimal design scheme.
[0126] It should be noted that the terms "comprising", "containing" or any other variant thereof in this document are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements not only includes those elements, but also includes other elements not explicitly listed, or inherent to such a process, method, article or apparatus.
[0127] The above examples are only used to illustrate the technical solutions of the present application, and not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A method for determining the type and dosage of a self-healing asphalt pavement sensing medium, characterized in that, The self-healing asphalt pavement comprises two layers of equal thickness, each containing different types and amounts of sensing media. The method for determining the type and amount of sensing media includes the following steps: S1. Preparation of upper and lower layers both doped with a volume fraction of [missing information]. Asphalt pavement test specimens with sensing medium, among which The absolute permeability of the sensing medium is μ0, and the resistivity is ρ0; S2. Conduct an induction heating test on the asphalt pavement test specimen in S1. Cut the specimen vertically and record the temperatures T1 and T2 at the centerline of the upper and lower layers of the specimen section. Let the initial temperature of the asphalt pavement test specimen be T0. Calculate the temperature changes ΔT1 = T1 - T0 and ΔT2 = T2 - T0 between the upper and lower layers of the specimen, and their average values. S3. Based on the temperature changes ΔT1 and ΔT2 of the upper and lower layers of the asphalt pavement test specimen in S2, and combined with the target induction heating efficiency during the heating process, determine the types of induction media for the upper and lower layers of the self-healing asphalt pavement test specimen. S4. Based on the types of sensing media in the upper and lower layers of the self-healing asphalt pavement test specimen determined in S3, calculate the optimal size of each layer of sensing media, and prepare self-healing asphalt pavement test specimens with corresponding sensing media types and sizes. S5. Conduct an induction heating test on the self-healing asphalt pavement test specimen from S4. Vertically cut the specimen and record the temperatures T1' and T2' at the centerline of the upper and lower layers on the specimen section. Let the initial temperature of the asphalt pavement test specimen be T0. Calculate the temperature changes ΔT1' = T1' - T0 and ΔT2' = T2' - T0 between the upper and lower layers of the specimen, and their average values. S6. Based on the temperature changes ΔT1' and ΔT2' of the upper and lower layers of the self-healing asphalt pavement test specimen in S5, determine the dosage of the induction medium in the upper and lower layers of the self-healing asphalt pavement test specimen, and prepare self-healing asphalt pavement test specimens with the corresponding dosage. S7. Determine the optimal design scheme for the type, size, and dosage of the upper and lower induction media corresponding to the self-healing asphalt pavement test specimen in step S6.
2. The method for determining the type and dosage of the induction medium for self-healing asphalt pavement according to claim 1, characterized in that, In step S3, the method for determining the type of sensing medium includes the following steps: ① Adjust the temperature changes ΔT1 and ΔT2 of the upper and lower layers of the self-healing asphalt pavement test specimen towards their average value. The absolute permeability and resistivity of the selected sensing medium should satisfy the following formula: Where i represents the layer of the self-healing asphalt pavement test specimen, i=1 represents the upper layer, i=2 represents the lower layer, and μ i 'ρ represents the absolute permeability of the i-th layer of the induction medium in the adjusted specimen.' i 'C represents the resistivity of the i-th layer of the sensing medium in the specimen after adjustment.' i Let c be the specific heat capacity of the i-th layer of the specimen in S1. i 'To determine the specific heat capacity of the i-th layer of the specimen after adjusting the type of induction medium, m' i Let m be the mass of the i-th layer of the specimen in S1. i 'The mass of the i-th layer of the specimen obtained after adjusting the type of sensing medium;' ② Ensure that the induction medium in the upper and lower layers of the self-healing asphalt pavement test specimen meets the requirements for induction heating efficiency, while narrowing down the range of media that satisfy the uniformity of the pavement test specimen. The absolute permeability and resistivity of the selected induction medium should meet the following requirements: Where η is the target induction heating efficiency, ρ c μ is the resistivity of the induction heating coil, and μ0 is the permeability of free space. ③ Based on the requirements in steps ① and ②, obtain the values of conductivity and absolute magnetic permeability of the induction medium that satisfy both the temperature uniformity of the upper and lower layers of the self-healing asphalt pavement test specimen and the induction heating efficiency, and determine the types of induction medium for the upper and lower layers of the test specimen.
3. The method for determining the type and dosage of the induction medium for self-healing asphalt pavement according to claim 2, characterized in that, In step S4, the formula for determining the optimal size of the sensing medium is: Where δ is the optimal radius of the sensing medium particles, and f is the induction heating frequency.
4. The method for determining the type and dosage of the induction medium for self-healing asphalt pavement according to claim 3, characterized in that, In step S6, the method for determining the doping amount of the sensing medium includes the following steps: ① To adjust the temperature changes ΔT1' and ΔT2' of the upper and lower layers of the self-healing asphalt pavement test specimen towards their average value. The calculation formula for the amount of induction medium in the upper and lower layers of self-healing asphalt pavement test specimens is as follows: Among them, c i 'where c is the specific heat capacity of the i-th layer of the specimen in S4. i "To adjust the specific heat capacity of the i-th layer of the specimen after adjusting the dosage of the induction medium, m" i 'where m is the mass of the i-th layer of the specimen in S4. i "This refers to the mass of the i-th layer of the specimen obtained after adjusting the dosage of the induction medium; ②According to the formula in ①, if the calculated dosage of the inductive medium in both the upper and lower layers of the self-healing asphalt pavement test specimen is less than or equal to... Then the doping amount of the upper and lower induction medium calculated by the formula in ① is the optimal doping amount of the induction medium. ③If the calculated doping concentration of any layer is greater than Then the doping level of this layer is adjusted to... And calculate when the doping content of the sensing medium in this layer is When induction heating occurs, the temperature change of the layer is... The calculation formula is: Based on the temperature change of this layer Determine the dosage of another inductive medium in the self-healing asphalt pavement test specimen. The calculation formula is: but and These represent the optimal dosage of the sensing medium in the corresponding layer of the self-healing asphalt pavement test specimen.
5. The method for determining the type and dosage of the induction medium for self-healing asphalt pavement according to claim 1, characterized in that, The specific heat capacity c of each layer of the specimen is: Where k is the number of material types in the specimen, c j Let λ be the specific heat capacity of the j-th material. j Let be the mass fraction of the j-th material.
6. The method for determining the type and dosage of the sensing medium for self-healing asphalt pavement according to claim 1, characterized in that, The mass m of each layer of the specimen is: Where k is the number of material types in the specimen, m j Let λ be the density of the j-th material. j Let be the mass fraction of the j-th material.
7. The method for determining the type and dosage of the induction medium for self-healing asphalt pavement according to claim 1, characterized in that, In step S1 The maximum amount of inductive medium used is determined to avoid affecting the pavement's performance characteristics, which include high-temperature stability, low-temperature crack resistance, and fatigue resistance.