Asphalt layer thickness measuring method based on metal powder-doped modified material and radar

Abstract

The invention discloses an asphalt layer thickness measurement method based on a metal powder-doped modified material and radar, and the method comprises the steps: arranging a bonding layer for bonding at the layering part of two adjacent asphalt layers, and enabling the bonding layer to comprise a first bonding region made of a first bonding material and a second bonding region made of a second bonding material, the first bonding areas and the second bonding areas are alternately distributed, the first bonding material is modified emulsified asphalt doped with metal powder, and for each asphalt layer, at least one electromagnetic wave channel through which electromagnetic waves can penetrate and reach the layering position of the asphalt layer and the next asphalt layer is arranged above the asphalt layer. Electromagnetic waves are emitted to the asphalt layer structures, the thickness of each asphalt layer is calculated according to the reflection time of the electromagnetic waves in each asphalt layer structure, and the method can accurately recognize the thicknesses of different asphalt layers with the dielectric constants similar to the detection dielectric constants.

Description

Technical Field

[0001] The invention relates to the technical field of road surface detection, and in particular to an asphalt layer thickness measurement method based on a metal powder-modified material and a radar. Background Art

[0002] The thickness of the asphalt pavement structure layer has a significant impact on the asphalt pavement in many aspects. The appropriate thickness can significantly improve the bearing capacity of the pavement, allowing it to better withstand the pressure brought by vehicle loads, traffic flow and environmental factors, thereby enhancing the stability of the pavement under heavy traffic or harsh environments, reducing the occurrence of rutting, cracks and other diseases, and ensuring the normal use and safety of the road.

[0003] The thickness detection of asphalt pavement structure layer usually adopts traditional methods such as pit digging method and drilling method. Although these methods can reflect the thickness of the pavement structure to a certain extent, they have certain limitations. For example, both pit digging method and drilling method are destructive detection, which will cause a certain degree of damage to the road surface, and the detection process is cumbersome and inefficient. In addition, these methods can often only provide local thickness information, and it is difficult to fully reflect the thickness distribution of the entire pavement structure.

[0004] The thickness detection method of ground penetrating radar is a non-destructive testing technology. It detects the thickness of the pavement structure layer by emitting high-frequency electromagnetic pulse waves underground and receiving the reflected signals. It is fast, accurate and continuous, and can provide more comprehensive thickness information. At present, ground penetrating radar has been widely used in the field of highway engineering as a technical means of process construction quality control and post-construction acceptance, and can realize the thickness detection of asphalt pavement structure layers in the surface area.

[0005] However, there are technical difficulties in using ground penetrating radar to detect the thickness of pavement structure layers, which is mainly related to the diversity, complexity, moisture content, and environmental factors of the dielectric constants of the materials used in the asphalt pavement structure layer. For two connected asphalt structure layers paved with materials with the same or similar dielectric constants, the reflection signal of the ground penetrating radar electromagnetic wave at the stratification interface will not be obvious, or even difficult to detect the reflection signal. Therefore, the ground penetrating radar cannot identify the stratification interface of the two structure layers, nor can it determine the specific thickness of two adjacent asphalt structure layers constructed at different times based on the reflection time course of the electromagnetic wave at the stratification interface.

[0006] Electromagnetic waves show extremely high sensitivity when encountering metal media and will produce strong reflection. This strong reflection makes metal media have important application value in fields such as ground penetrating radar, and can provide a reliable physical basis for technologies such as non-destructive testing of pavement structure layer thickness.

[0007] The properties of the materials used in the construction of different asphalt layers of the same project are often similar, and the dielectric constants of different asphalt layers after paving are similar. Therefore, the reflection signal of the electromagnetic wave of the ground penetrating radar at the layering interface of two adjacent asphalt layers will not be obvious. Due to the influence of the environment, some sections even have no reflection signal. The ground penetrating radar cannot identify the layering interface of two adjacent asphalt layers, so it is impossible to determine the specific thickness of two adjacent asphalt structural layers constructed at different times based on the reflection time history of the electromagnetic wave at the layering interface. For example, the ground penetrating radar non-destructive testing method can clearly identify the layering interface of the asphalt layer and the cement-stabilized crushed stone layer with large differences in dielectric constants, but it cannot separately identify the thickness of the asphalt upper layer, asphalt middle layer, and asphalt lower layer with small differences in dielectric constants. This technical problem is more prominent in the detection of the thickness of the preventive maintenance thin layer of asphalt pavement. The difficulty in identifying the layer thickness of the asphalt layer will not only cause the thickness of different structural layers to deviate from the designed layer thickness during the construction of the asphalt pavement, and the structural life and functional life of the entire pavement may be affected, but also cause difficulties in the engineering measurement of the layer thickness during the construction of the asphalt pavement, especially in the detection of the thickness of the preventive maintenance thin layer.

[0008] The solution proposed in the present invention is to provide a bonding layer for bonding at the stratification of two adjacent asphalt layers, wherein the bonding layer includes a first bonding area made of a first bonding material and a second bonding area made of a second bonding material, wherein the first bonding area and the second bonding area are alternately distributed, and the first bonding material is a modified emulsified asphalt doped with metal powder, and for each asphalt layer, there is at least one electromagnetic wave channel above the asphalt layer for electromagnetic waves to pass through and reach the stratification point between the asphalt layer and the next asphalt layer, and electromagnetic waves are emitted to the asphalt layer structure, and the thickness of each asphalt layer is calculated according to the reflection time of the electromagnetic waves in each asphalt layer structure. This method can accurately identify and detect different asphalt layer thicknesses with similar dielectric constants. Summary of the invention

[0009] In order to solve the above-mentioned technical problems, the present invention provides an asphalt layer thickness measurement method based on metal powder modified materials and radar.

[0010] The technical solution of the present invention is implemented as follows: the asphalt layer thickness measurement method based on the metal powder modified material and radar is applied to an asphalt layer structure having at least two layers, and a bonding layer for bonding is provided at the layering of two adjacent asphalt layers, including:

[0011] The bonding layer comprises a first bonding area made of a first bonding material and a second bonding area made of a second bonding material, the first bonding area and the second bonding area are alternately distributed, the first bonding material is a modified emulsified asphalt doped with metal powder, and for each asphalt layer, there is at least one electromagnetic wave channel above the asphalt layer for electromagnetic waves to pass through and reach the separation point between the asphalt layer and the next asphalt layer; the asphalt layer thickness measurement method comprises the following steps:

[0012] Electromagnetic waves are emitted to the asphalt layer structures, and the thickness of each asphalt layer is calculated according to the reflection time of the electromagnetic waves in each asphalt layer structure.

[0013] Furthermore, the metal powder includes one or more of steel slag powder, pig iron powder, and cast iron powder. The particle size of the metal powder ranges from 0.5 microns to 44 microns. The Fe content in the metal powder is not less than 95%.

[0014] Furthermore, the technical standard of the modified emulsified asphalt doped with metal powder is:

[0015] The residue on the sieve (1.18mm sieve, 25℃) is not more than 0.05%, the viscosity (bitumen standard viscometer C 25,3 ) is between 8 and 25s, the residual content of the evaporation residue is not less than 65%, the needle penetration (25℃) is between 60 and 150 (0.1mm), the elongation (5℃) is not less than 40cm, the solubility is not less than 97.5%, and the storage stability (24h) is not more than 1%.

[0016] Furthermore, the electromagnetic wave channel is configured as follows:

[0017] When the asphalt layer structure has two layers, one side area of ​​the bonding layer is set as the first bonding area, and the other side area is set as the second bonding area;

[0018] When the asphalt layer structure has three or more layers, at least one of the first bonding area and at least one of the second bonding area are arranged in each bonding layer, and the first bonding area and the second bonding area of ​​two adjacent bonding layers are staggered, so that above each asphalt layer, at least one electromagnetic wave channel formed by partial overlap of multiple second bonding areas is formed.

[0019] Furthermore, the thickness of each asphalt layer is calculated as follows:

[0020] For each asphalt layer, the electromagnetic wave reflection time of the electromagnetic wave in the asphalt layer entering the reflection area at the delamination between the asphalt layer and the next asphalt layer from one or more electromagnetic wave channels and reflected back is obtained; for multiple electromagnetic wave reflection times reflected back at the delamination of the asphalt layers of the same two adjacent layers, the reflection time of the multiple electromagnetic wave reflection times at the delamination is calculated as the reflection time reflected back at the delamination of the asphalt layer, and the reflection time of each asphalt layer structure is calculated based on the electromagnetic wave reflection time, and then the thickness of each asphalt layer is calculated based on the reflection time of each asphalt layer structure;

[0021] Furthermore, the average value of the electromagnetic wave reflection time is calculated as:

[0022]

[0023] Among them, t' is the average reflection time of multiple electromagnetic waves reflected from the delamination of the same two adjacent asphalt layers, t n is the reflection time of n electromagnetic waves reflected from the delamination of the same two adjacent asphalt layers, and x, y, z are the channel numbers of the electromagnetic waves;

[0024] Furthermore, the reflection time in each asphalt layer structure is calculated as:

[0025] When the number of asphalt layers is two:

[0026] The reflection time of electromagnetic waves on the upper layer of the asphalt layer is:

[0027] Δt A =t2

[0028] Among them, Δt A is the reflection time of the electromagnetic wave on the upper layer of the asphalt layer, and t2 is the reflection time of the electromagnetic wave when it reaches the stratification between the bottom of the upper layer of the asphalt layer and the surface of the lower layer of the asphalt layer;

[0029] The reflection time of electromagnetic waves in the layer below the asphalt layer is:

[0030] Δt B =t1-t2

[0031] Among them, Δt B is the reflection time of the electromagnetic wave in the layer below the asphalt layer, t1 is the reflection time of the electromagnetic wave when it reaches the stratification between the bottom of the layer below the asphalt layer and the surface of the gravel layer, and t2 is the reflection time of the electromagnetic wave when it reaches the stratification between the bottom of the layer above the asphalt layer and the surface of the layer below the asphalt layer;

[0032] When the number of asphalt layers is three or more:

[0033] The reflection time of electromagnetic waves in each asphalt layer structure is:

[0034] Δt i =t i -t i+1

[0035] Among them, Δt i is the reflection time of electromagnetic wave in the i-th asphalt layer, t i is the reflection time of the electromagnetic wave when it reaches the delamination point between the bottom of the i-th asphalt layer and the surface of the i-1-th asphalt layer, t i+1 is the reflection time of the electromagnetic wave when it reaches the delamination point between the bottom of the i+1th asphalt layer and the surface of the ith asphalt layer;

[0036] For the top asphalt layer, the reflection time is the reflection time when the electromagnetic wave reaches the delamination point between the bottom of the top asphalt layer and the surface of the next asphalt layer;

[0037] Furthermore, the thickness of each asphalt layer is calculated as:

[0038]

[0039] Among them, h i is the thickness of the i-th asphalt layer, v is the propagation speed of electromagnetic waves, Δt i is the reflection time of the electromagnetic wave in the i-th asphalt layer.

[0040] Beneficial Effects

[0041] The present invention provides an adhesive layer for bonding at the stratification of two adjacent asphalt layers, wherein the adhesive layer includes a first bonding area made of a first adhesive material and a second bonding area made of a second adhesive material, the first bonding area and the second bonding area are alternately distributed, the first adhesive material is a modified emulsified asphalt doped with metal powder, and for each asphalt layer, there is at least one electromagnetic wave channel above the asphalt layer for electromagnetic waves to pass through and reach the stratification point between the asphalt layer and the next asphalt layer, electromagnetic waves are emitted to the asphalt layer structure, and the thickness of each asphalt layer is calculated according to the reflection time of the electromagnetic wave in each asphalt layer structure. This method can accurately identify and detect the thickness of different asphalt layers with similar dielectric constants. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural block diagram of an asphalt layer thickness measurement method based on a metal powder modified material and a radar in an embodiment of the present invention;

[0043] Figure 2 It is a schematic diagram of the surface setting of the first asphalt layer of the asphalt layer thickness measurement method based on the metal powder modified material and radar in an embodiment of the present invention;

[0044] Figure 3It is a schematic diagram of the surface setting of the second layer of the asphalt layer in the asphalt layer thickness measurement method based on the metal powder modified material and radar in an embodiment of the present invention;

[0045] Figure 4 It is a schematic diagram of the surface setting of the third layer of the asphalt layer in the asphalt layer thickness measurement method based on the metal powder modified material and radar in an embodiment of the present invention;

[0046] Figure 5 Schematic diagram of the AA section of an asphalt layer of an asphalt layer thickness measurement method based on a metal powder modified material and radar in an embodiment of the present invention;

[0047] Figure 6 It is a schematic diagram of electromagnetic wave reflection of the asphalt layer thickness measurement method based on metal powder modified material and radar in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] The preferred implementation methods of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these implementation methods are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0050] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0051] See also Figure 1-Figure 6 As shown, the asphalt layer thickness measurement method based on metal powder modified material and radar according to the embodiment of the present invention is applied to an asphalt layer structure having at least two layers, and a bonding layer for bonding is provided at the layering of two adjacent asphalt layers, including:

[0052] The bonding layer comprises a first bonding area made of a first bonding material and a second bonding area made of a second bonding material, the first bonding area and the second bonding area are alternately distributed, the first bonding material is a modified emulsified asphalt doped with metal powder, and for each asphalt layer, there is at least one electromagnetic wave channel above the asphalt layer for electromagnetic waves to pass through and reach the separation point between the asphalt layer and the next asphalt layer; the asphalt layer thickness measurement method comprises the following steps:

[0053] Electromagnetic waves are emitted to the asphalt layer structures, and the thickness of each asphalt layer is calculated according to the reflection time of the electromagnetic waves in each asphalt layer structure.

[0054] Specifically, in this embodiment, the materials of the first bonding area 1 and the second bonding area 2 are modified emulsified asphalt doped with metal powder and conventional modified emulsified asphalt, respectively. The first bonding area 1 is prepared by doping the metal powder into the first bonding material. The preparation method is to uniformly distribute the metal powder in the conventional modified emulsified asphalt by mechanical stirring to obtain the first bonding area 1. The mechanical stirring includes one of paddle stirring, propeller stirring, turbine stirring and anchor stirring. The stirring rate is 300-500 rpm. The metal powder includes but is not limited to one or more of steel slag powder, pig iron powder and cast iron powder. The particle size range of the metal powder should be controlled within a range of 0.5 to 44 microns. This particle size range can ensure that the metal powder has good dispersibility and stability in the first bonding material. At the same time, the Fe content in the metal powder is not less than 95%. A higher iron content can further enhance the metal powder's ability to reflect electromagnetic waves. The technical standard of the modified emulsified asphalt doped with metal powder obtained by the preparation method in this embodiment meets Table 1.

[0055] Table 1

[0056]

[0057] Specifically, if Figure 2-Figure 5 As shown, the electromagnetic wave channel is set as:

[0058] When the asphalt layer structure has two layers, one side area of ​​the bonding layer is set as the first bonding area 1, and the other side area is set as the second bonding area 2, so as to form an electromagnetic wave channel;

[0059] When the asphalt layer structure has three or more layers, at least one of the first bonding areas 1 and at least one of the second bonding areas 2 are arranged in each bonding layer, and the first bonding areas 1 and the second bonding areas 2 of two adjacent bonding layers are alternately distributed, so that above each asphalt layer, at least one electromagnetic wave channel formed by partial overlap of multiple layers of the second bonding areas 2 is formed.

[0060] In this embodiment, the number of asphalt layers is set to 3, namely, the third asphalt layer (as the upper layer), the second asphalt layer (as the middle layer), and the first asphalt layer (as the lower layer). A crushed stone layer 3 is also provided, and the crushed stone layer 3 is located below the first asphalt layer. This layer design is based on a common asphalt pavement structure and meets the requirements of this application for processing different layers.

[0061] After the first asphalt layer is constructed, it is necessary to use an asphalt sprayer on the upper surface at a rate of 0.8 to 1.2 L / m 2 The first bonding layer is sprayed in an alternating manner of second bonding area 2-first bonding area 1-second bonding area 2. Such a spraying method can form a suitable bonding layer between the first asphalt layer and the subsequent layers, and also provides conditions for the reflection of electromagnetic waves;

[0062] After the first asphalt layer is set, the second asphalt layer is constructed, and the second bonding layer is sprayed on the upper surface in an alternating manner of the first bonding area 1-the second bonding area 2-the first bonding area 1. The adjustment of this spraying method is to stagger the first bonding area 1 and the second bonding area 2 of the two adjacent bonding layers, so as to allow the electromagnetic wave propagation path to penetrate the adjacent layers and better realize the reflection of the electromagnetic wave.

[0063] After the second asphalt layer is set, the third asphalt layer is constructed. For the third asphalt layer, in order to avoid excessive interference with the upper structure of the road surface and maintain the relative flatness and durability of the road surface, the bonding layer including the first bonding area 1 is not constructed on its surface;

[0064] For the crushed stone layer 3, since its dielectric constant is greatly different from that of the asphalt layer and the reflection signal of the delamination interface is strong, the bonding layer including the first bonding area 1 is not constructed on its surface.

[0065] Specifically, if Figure 6 As shown in Figure 2, the process of calculating the thickness of each asphalt layer is:

[0066] For each asphalt layer, the electromagnetic wave reflection time of the electromagnetic wave in the asphalt layer entering the reflection area at the delamination between the asphalt layer and the next asphalt layer from one or more electromagnetic wave channels and reflected back is obtained; for multiple electromagnetic wave reflection times reflected back at the delamination of the asphalt layers of the same two adjacent layers, the reflection time of the multiple electromagnetic wave reflection times at the delamination is calculated as the reflection time reflected back at the delamination of the asphalt layer, and the reflection time of each asphalt layer structure is calculated based on the electromagnetic wave reflection time, and then the thickness of each asphalt layer is calculated based on the reflection time of each asphalt layer structure;

[0067] In this embodiment, after the setting of the reflection zone of the asphalt layer is completed, the ground penetrating radar equipment is arranged above the surface of the third layer of asphalt layer, wherein the ground penetrating radar model can be any one of SIR-4000, TH-DZLD1 and DZLD-4000, and is not limited to the use of these specific models;

[0068] After the arrangement is completed, the ground penetrating radar is started to transmit electromagnetic waves with a frequency of 100MHz to the asphalt structure layer. The propagation speed of the electromagnetic waves is calculated as:

[0069]

[0070] Where v is the propagation speed of electromagnetic waves in the asphalt layer, c is the propagation speed of electromagnetic waves in vacuum, ε i is the relative dielectric constant of the i-th asphalt layer;

[0071] In the above formula, the propagation speed of electromagnetic waves in vacuum is 3×10 8 m / s, when the electromagnetic wave frequency is 100MHz, the relative dielectric constant of the asphalt layer ranges from 3 to 5. Considering that the material properties of different asphalt layers in the same project are often similar, the dielectric constants of different asphalt layers after paving are very similar. Therefore, the relative dielectric constant of electromagnetic waves in each layer is taken as 4. Substituting the data into the formula for calculation, the propagation speed of electromagnetic waves is 0.15m / ns.

[0072] The electromagnetic wave enters the delamination between the bottom of the first asphalt layer and the gravel layer 3 through channels 5 and 11, enters the first bonding layer 1 through channels 6, 8, and 10, and enters the second bonding layer 2 through channels 4, 7, 9, and 12. After strong reflection, it is transmitted back to the signal antenna of the ground penetrating radar. The reflection time of the electromagnetic wave in channel 5 is 2.1ns, the reflection time in channel 11 is 2.3ns, the reflection time in channel 6 is 1.1ns, the reflection time in channel 8 is 1.2ns, the reflection time in channel 10 is 1.3ns, the reflection time in channel 4 is 0.3ns, the reflection time in channel 7 is 0.5ns, the reflection time in channel 9 is 0.2ns, and the reflection time in channel 12 is 0.6ns. The reflection time of the electromagnetic wave reflected back from the delamination of the asphalt layers of the same two adjacent layers is calculated as follows:

[0073] The reflection time t1 at the delamination point between the bottom of the first asphalt layer and the crushed stone layer is:

[0074]

[0075] The reflection time t2 of the delamination point between the bottom of the second asphalt layer and the first asphalt layer (the first bonding layer 1) is:

[0076]

[0077] The reflection time t3 of the delamination point between the bottom of the III asphalt layer and the II asphalt layer (the second bonding layer 2) is:

[0078]

[0079] The average reflection time t1 of the delamination between the bottom of the first asphalt layer and the gravel layer is 2.2ns, the average reflection time t2 of the delamination between the bottom of the second asphalt layer and the first asphalt layer (the first bonding layer 1) is 1.2ns, and the average reflection time t3 of the delamination between the bottom of the third asphalt layer and the second asphalt layer (the second bonding layer 2) is 0.4ns. The reflection time of the electromagnetic wave in the first asphalt layer is calculated as:

[0080] Δt I =t1-t2=2.2-1.2=1ns

[0081] The reflection time of electromagnetic waves in the second layer of asphalt is:

[0082] Δt II =t2-t3=1.2-0.4=0.8ns

[0083] The reflection time of electromagnetic waves in the third asphalt layer is:

[0084] Δt III =t3=0.4ns

[0085] After obtaining the reflection time of each layer, the thickness of each layer is calculated using the thickness detection formula. The thickness of each layer is calculated as:

[0086] The thickness of the first asphalt layer is:

[0087]

[0088] The thickness of the second asphalt layer is:

[0089]

[0090] The thickness of the third asphalt layer is:

[0091]

[0092] By calculation, the thickness of different asphalt layers with similar dielectric constants can be obtained as follows:

[0093] The thickness of the first asphalt layer is 7.5 cm;

[0094] The thickness of the second asphalt layer is 6cm;

[0095] The thickness of the third asphalt layer is 3 cm.

[0096] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and rules of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for measuring the thickness of an asphalt layer based on a metal powder modified material and radar is applied to an asphalt layer structure having at least two layers, wherein a bonding layer for bonding is provided at the layering of two adjacent asphalt layers, and is characterized in that: The bonding layer comprises a first bonding area made of a first bonding material and a second bonding area made of a second bonding material, the first bonding area and the second bonding area are alternately distributed, the first bonding material is a modified emulsified asphalt doped with metal powder, and for each asphalt layer, there is at least one electromagnetic wave channel above the asphalt layer for electromagnetic waves to pass through and reach the separation point between the asphalt layer and the next asphalt layer; the asphalt layer thickness measurement method comprises the following steps: Electromagnetic waves are emitted to the asphalt layer structures, and the thickness of each asphalt layer is calculated according to the reflection time of the electromagnetic waves in each asphalt layer structure.

2. The asphalt layer thickness measurement method based on metal powder modified material and radar according to claim 1 is characterized in that: The metal powder comprises one or more of steel slag powder, pig iron powder and cast iron powder. The particle size of the metal powder ranges from 0.5 microns to 44 microns. The Fe content in the metal powder is not less than 95%.

3. The asphalt layer thickness measurement method based on metal powder modified material and radar according to claim 1 or 2, characterized in that: The technical standards of the modified emulsified asphalt doped with metal powder are: The residue on the sieve is not more than 0.05%, the viscosity is between 8 and 25s, the residual content of the evaporation residue is not less than 65%, the needle penetration is between 60 and 150, the needle penetration unit is 0.1mm, the elongation is not less than 40cm, the solubility is not less than 97.5%, and the storage stability is not more than 1%.

4. The asphalt layer thickness measurement method based on metal powder modified material and radar according to claim 1 is characterized in that: The electromagnetic wave channel is set as follows: When the asphalt layer structure has two layers, one side area of ​​the bonding layer is set as the first bonding area, and the other side area is set as the second bonding area; When the asphalt layer structure has three or more layers, at least one of the first bonding area and at least one of the second bonding area are arranged in each bonding layer, and the first bonding area and the second bonding area of ​​two adjacent bonding layers are staggered, so that above each asphalt layer, at least one electromagnetic wave channel formed by partial overlap of multiple second bonding areas is formed.

5. The asphalt layer thickness measurement method based on metal powder modified material and radar according to claim 1 is characterized in that: The process of calculating the thickness of each asphalt layer is: For each asphalt layer, the reflection time of the electromagnetic wave in the asphalt layer entering the reflection area at the stratification between the asphalt layer and the next asphalt layer from one or more electromagnetic wave channels and reflected back is obtained. For multiple reflection times of electromagnetic waves reflected back at the stratification of the asphalt layers of the same two adjacent asphalt layers, the average value of the multiple electromagnetic wave reflection times at the stratification is calculated as the reflection time reflected back at the stratification of the asphalt layer, and the reflection time of each asphalt layer structure is calculated based on the electromagnetic wave reflection time, and then the thickness of each asphalt layer is calculated based on the reflection time of each asphalt layer structure.

6. The asphalt layer thickness measurement method based on metal powder modified material and radar according to claim 5 is characterized in that: The electromagnetic wave reflection time average value is calculated as: Among them, t' is the average reflection time of multiple electromagnetic waves reflected from the delamination of the same two adjacent asphalt layers, t n is the reflection time of n electromagnetic waves reflected from the delamination of the asphalt layers of the same two adjacent layers, and x, y, z are the channel numbers of the electromagnetic waves.

7. The asphalt layer thickness measurement method based on metal powder modified material and radar according to claim 5 is characterized by: The reflection time in each asphalt layer structure is calculated as: When the number of asphalt layers is two: The reflection time of electromagnetic waves on the upper layer of the asphalt layer is: Δt A =t2 Among them, Δt A is the reflection time of the electromagnetic wave on the upper layer of the asphalt layer, and t2 is the reflection time of the electromagnetic wave when it reaches the stratification between the bottom of the upper layer of the asphalt layer and the surface of the lower layer of the asphalt layer; The reflection time of electromagnetic waves in the layer below the asphalt layer is: Δt B =t1-t2 Among them, Δt B is the reflection time of the electromagnetic wave in the layer below the asphalt layer, t1 is the reflection time of the electromagnetic wave when it reaches the stratification between the bottom of the layer below the asphalt layer and the surface of the gravel layer, and t2 is the reflection time of the electromagnetic wave when it reaches the stratification between the bottom of the layer above the asphalt layer and the surface of the layer below the asphalt layer; When the number of asphalt layers is three or more: The reflection time of electromagnetic waves in each asphalt layer structure is: Δt i =t i -t i+1 Among them, Δt i is the reflection time of electromagnetic wave in the i-th asphalt layer, t i is the reflection time of the electromagnetic wave when it reaches the delamination point between the bottom of the i-th asphalt layer and the surface of the i-1-th asphalt layer, t i+1 is the reflection time of the electromagnetic wave when it reaches the delamination point between the bottom of the i+1th asphalt layer and the surface of the ith asphalt layer; For the uppermost asphalt layer, the reflection time is the reflection time when the electromagnetic wave reaches the stratification point between the bottom of the uppermost asphalt layer and the surface of the next asphalt layer and is reflected back.

8. The asphalt layer thickness measurement method based on metal powder modified material and radar according to claim 5 is characterized in that: The thickness of each asphalt layer is calculated as: Among them, h i is the thickness of the i-th asphalt layer, v is the propagation speed of electromagnetic waves, Δt i is the reflection time of the electromagnetic wave in the i-th asphalt layer.

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