Construction method and system for lower sealing layer based on simultaneous tack coat curing of elastomeric asphalt

Abstract

This invention discloses a method and system for constructing a lower seal layer based on simultaneous tack coat curing of elastomeric asphalt, relating to the field of road construction technology. The method involves obtaining the surface texture depth and average pore size parameters of a semi-rigid base course, outputting the parameter indices of the first and second emulsion layers using a permeability-modulus mapping algorithm, preparing the first and second emulsion layers, uniformly spraying the first emulsion onto the base course surface, and calculating the wetting index in real time using an image color difference analysis algorithm. When the wetting index reaches or exceeds the target wetting index, the spraying of the second emulsion layer is initiated. The second emulsion layer is then uniformly sprayed onto the base course surface, and the demulsification index is calculated in real time using the image color difference analysis algorithm. When the demulsification index enters a preset semi-demulsification range, the aggregate spreading operation is initiated, and a steel wheel roller is used for final compaction and locking, forming the elastomeric asphalt lower seal layer. Through a two-component gradient emulsion system, a continuous transition of the elastic modulus from the base course to the asphalt surface layer is achieved, improving the reliability of asphalt construction.

Description

Technical Field

[0001] This invention relates to the field of road construction technology, specifically to a method and system for constructing a lower sealing layer based on simultaneous tack coat curing of elastomeric asphalt. Background Technology

[0002] Currently, in the construction of semi-rigid base courses (such as cement-stabilized crushed stone) for road engineering, the base course needs to be moisturized and cured after paving and compaction to build strength. Simultaneously, a tack coat and a sub-seal coat are required between the base course and the asphalt surface layer to provide interlayer bonding, waterproofing, and stress absorption. Traditional methods typically separate curing and tack / seal coat application, resulting in long processing times and low construction reliability. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides a method and system for constructing a lower seal layer based on simultaneous tack coat curing of elastomeric asphalt. Through a two-component gradient emulsion system, it achieves a continuous transition of elastic modulus from the base layer to the asphalt surface layer and ensures the precise formation of the crushed stone interlocking structure, thereby improving the reliability of asphalt construction.

[0004] This invention provides a method for constructing a lower seal layer based on simultaneous tack coat curing with elastomeric asphalt, the method comprising: After the semi-rigid base course is laid and compacted, the surface texture depth and average pore size parameters of the semi-rigid base course are obtained. Based on the surface texture depth and average pore size parameters of the base layer, the bitumen content ratio and first spraying amount of the first layer emulsion, the bitumen content ratio and second spraying amount of the second layer emulsion, and the target wetting index are output through the permeability-modulus mapping algorithm, wherein the bitumen content ratio of the first layer emulsion is lower than that of the second layer emulsion. Based on the asphalt content ratio of the first emulsion, a first emulsion is prepared using rubber powder as a modifier and combined with a slow-cracking emulsifier. Based on the asphalt content ratio of the second emulsion, a second emulsion is prepared using SBS as a modifier and combined with a medium-cracking emulsifier. The first layer of emulsion is evenly sprayed onto the base surface according to the first spraying amount. After spraying, an industrial camera is started to continuously collect images of the sprayed surface. The current wetting index of the semi-rigid base is calculated in real time through an image color difference analysis algorithm. When the current wetting index reaches or exceeds the target wetting index, the spraying of the second layer of emulsion is initiated. The second layer of emulsion is evenly sprayed onto the base surface according to the second spraying amount. After spraying, the sprayed surface image is continuously collected by an industrial camera, and the current demulsification index of the semi-rigid base is calculated in real time by an image color difference analysis algorithm. When the current demulsification index enters the preset semi-demulsification range, the crushed stone spreading operation is started, and the steel wheel roller is used for final compaction and locking to form an elastomeric asphalt under-sealing layer.

[0005] Furthermore, the step of outputting the bitumen content ratio and first spraying amount of the first emulsion, the bitumen content ratio and second spraying amount of the second emulsion, and the target wetting index based on the surface texture depth and average pore size parameters of the base layer using a permeability-modulus mapping algorithm includes: The average pore size and surface porosity of the semi-rigid base layer, as well as the dynamic viscosity, surface tension, and gel demulsification time of the first emulsion layer, are obtained. The average pore size, surface tension, dynamic viscosity, and gel demulsification time are substituted into the capillary permeation equation for calculation to obtain the expected penetration depth of the first emulsion layer. The first spraying amount of the first layer of emulsion is calculated by multiplying the expected penetration depth, surface porosity and preset effective filling coefficient. Based on the pre-calibrated curve of the elastic modulus of the second emulsion after curing and the asphalt content, the asphalt content required for the second emulsion is selected in reverse with the elastic modulus range of the target film layer, and then the second spraying amount of the second emulsion is calculated by combining it with the preset target film thickness. Based on the pre-defined correspondence between penetration depth and surface wetting area ratio, the target wetting index corresponding to the expected penetration depth is determined and output.

[0006] Furthermore, the step of uniformly spraying the first layer of emulsion onto the substrate surface according to the first spraying amount, and then continuously acquiring images of the sprayed surface using an industrial camera after spraying, and calculating the current wetting index of the semi-rigid substrate in real time using an image color difference analysis algorithm includes: Convert the current frame color image captured by the industrial camera into the Lab color space, extract the first brightness channel, and calculate the average value of the first brightness channel; Read the first dry lightness value of the pre-calibrated dry substrate surface and the reference wetted lightness value when the emulsion is fully wetted; The current wetting index is obtained by performing a normalized difference operation on the first dry lightness value, the reference wet lightness value, and the first lightness average value.

[0007] Furthermore, the step of uniformly spraying the first layer of emulsion onto the substrate surface according to the first spraying amount, and then continuously acquiring images of the sprayed surface using an industrial camera after spraying, and calculating the current wetting index of the semi-rigid substrate in real time using an image color difference analysis algorithm, also includes: Automatic thresholding is performed on the first brightness channel, and pixel regions with brightness values ​​lower than a preset segmentation threshold are marked as immersion regions. The number of pixels in the infiltrated region is counted, and the area ratio of the number of pixels in the infiltrated region to the total number of pixels in the image is calculated. The area ratio is cross-validated with the infiltration index obtained by normalized difference calculation, and the verification result is used as the basis for confirming the current infiltration index.

[0008] Furthermore, the process of uniformly spraying a second layer of emulsion onto the substrate surface according to the second spraying amount, and then continuously acquiring images of the sprayed surface using an industrial camera after spraying, and calculating the current demulsification index of the semi-rigid substrate in real time using an image color difference analysis algorithm, includes: The current frame color image captured by the industrial camera is converted into the Lab color space, the second brightness channel is extracted, and the average value of the second brightness channel is calculated. Read the lowest brightness value of the image at the moment the second layer of emulsion is sprayed and the second dry brightness value of the pre-calibrated dry substrate surface; Using the current average second brightness value, the lowest brightness value, and the second dry brightness value as inputs, a normalized ratio calculation is performed to obtain the current demulsification index.

[0009] Furthermore, the step of uniformly spraying a second layer of emulsion onto the substrate surface according to the second spraying amount, and then continuously acquiring images of the sprayed surface using an industrial camera, and calculating the current demulsification index of the semi-rigid substrate in real time using an image color difference analysis algorithm, also includes: Calculate the first-order difference between the average brightness values ​​of the current frame and the previous frame; When the current demulsification index enters the preset semi-demulsification range, and the first-order difference value corresponding to multiple consecutive frames is lower than the preset brightness change threshold, the second layer of emulsion is determined to have entered the semi-demulsification state and the gravel spreading is triggered.

[0010] Furthermore, the preset semi-demulsification interval ranges from 0.4 to 0.6.

[0011] Furthermore, the step of initiating the aggregate spreading operation when the current demulsification index enters the preset semi-demulsification range, and cooperating with a steel wheel roller for final compaction and locking to form an elastomeric asphalt undersea layer, includes: Single-size crushed stone is spread on the surface of the semi-rigid base course, and the crushed stone coverage is maintained within the range where the asphalt film layer on the base course surface is exposed black. A rubber-tired roller is used to perform initial compaction with low tire pressure. After the emulsion has completely demulsified and solidified, a steel wheel roller is used to apply a higher linear pressure than a rubber-tired roller to lock the elastomer asphalt undersealing layer.

[0012] Furthermore, the step of initiating the aggregate spreading operation when the current demulsification index enters the preset semi-demulsification range, and cooperating with a steel wheel roller for final compaction and locking to form an elastomeric asphalt undersea layer, includes: During the gravel spreading operation, a photoelectric sensor is used to collect the black-and-white pixel ratio signal of the base surface image in real time, and the opening of the spreading gate is adjusted according to the feedback of the signal.

[0013] The present invention also provides a lower seal coat construction system based on simultaneous tack coat curing of elastomeric asphalt, the construction system comprising: Data acquisition module: used to acquire the surface texture depth and average pore size parameters of the semi-rigid base course after the semi-rigid base course is laid and compacted; Data calculation module: used to output the bitumen content ratio and first spraying amount of the first layer emulsion, the bitumen content ratio and second spraying amount of the second layer emulsion, and the target wetting index based on the surface texture depth and average pore size parameters of the base layer through the permeability-modulus mapping algorithm, wherein the bitumen content ratio of the first layer emulsion is lower than the bitumen content ratio of the second layer emulsion. Dual-emulsion preparation module: used to prepare the first emulsion by using rubber powder as a modifier and combining it with a slow-cracking emulsifier according to the asphalt content ratio of the first emulsion; and to prepare the second emulsion by using SBS as a modifier and combining it with a medium-cracking emulsifier according to the asphalt content ratio of the second emulsion. First emulsification module: used to uniformly spray the first layer of emulsion onto the base surface according to the first spraying amount, and after spraying, start the industrial camera to continuously collect images of the sprayed surface, and calculate the current wetting index of the semi-rigid base in real time through the image color difference analysis algorithm; When the current wetting index reaches or exceeds the target wetting index, the spraying of the second layer of emulsion is initiated. The second emulsification module is used to uniformly spray the second layer of emulsion onto the surface of the base layer according to the second spraying amount. After spraying, it continues to collect images of the sprayed surface through an industrial camera and calculates the current demulsification index of the semi-rigid base layer in real time through an image color difference analysis algorithm. When the current demulsification index enters the preset semi-demulsification range, the crushed stone spreading operation is started, and the steel wheel roller is used for final compaction and locking to form an elastomeric asphalt under-sealing layer.

[0014] This invention provides a method and system for constructing a lower seal layer based on simultaneous tack coat curing of elastomeric asphalt. Through a two-component gradient emulsion system, it achieves a continuous transition of elastic modulus from the base layer to the asphalt surface layer and ensures the precise formation of the crushed stone interlocking structure, thereby improving the reliability of asphalt construction. Attached Figure Description

[0015] Figure 1 This is a flowchart of the construction method of the lower sealing layer construction method based on simultaneous tack curing of elastomeric asphalt in the embodiments of the present invention; Figure 2This is a flowchart of the proportioning operation method of elastomeric asphalt in an embodiment of the present invention; Figure 3 This is a schematic diagram of the construction system described in the embodiment of the present invention for the construction method of lower sealing layer based on simultaneous tack coat curing of elastomeric asphalt. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0017] Example 1: Please refer to Figure 1 and Figure 2 This invention provides a method for constructing a lower sealing layer based on simultaneous tack coat curing with elastomeric asphalt. The construction method includes: S100: After the semi-rigid base course is laid and compacted, the surface texture depth and average pore size parameters of the semi-rigid base course are obtained; Semi-rigid base courses typically refer to base course structures such as cement-stabilized crushed stone that possess a certain degree of rigidity but still exhibit microcracks and pores. Surface texture depth reflects the macroscopic roughness of the base course surface, while the average pore size parameter characterizes the scale characteristics of the micropores on the base course surface. These parameters form the physical basis for subsequent algorithms to calculate penetration depth and spray volume.

[0018] Furthermore, the structural depth can be determined by the sand-spreading method, and the average pore size can be determined by drilling core samples and using mercury intrusion porosimetry or hydrodynamics in the laboratory, thereby obtaining the structural parameters of the semi-rigid base layer.

[0019] S200: Based on the surface texture depth and average pore size parameters of the base layer, the bitumen content ratio and first spraying amount of the first layer emulsion, the bitumen content ratio and second spraying amount of the second layer emulsion, and the target wetting index are output through the permeability-modulus mapping algorithm, wherein the bitumen content ratio of the first layer emulsion is lower than the bitumen content ratio of the second layer emulsion. Based on the surface texture depth and average pore size parameters of the substrate, the viscosity and demulsification time parameters of the first emulsion layer are obtained. A penetration-modulus mapping algorithm is then run, outputting the target spray volume for the first emulsion layer, the target spray volume for the second emulsion layer, and the target wetting index. Specifically, the penetration-modulus mapping algorithm is a physical model that binds the physical parameters of the substrate to the fluid parameters of the emulsion. It directly outputs the target control values ​​required for construction, without relying on complex finite element iterations or manual estimation. The target spray volume determines the amount of emulsion used, while the target wetting index serves as the benchmark threshold for subsequent dynamic triggering actions.

[0020] S300: Based on the asphalt content ratio of the first layer emulsion, a first layer emulsion is prepared using rubber powder as a modifier and combined with a slow-cracking emulsifier; based on the asphalt content ratio of the second layer emulsion, a second layer emulsion is prepared using SBS as a modifier and combined with a medium-cracking emulsifier. Specifically, a first-layer emulsion is prepared using rubber powder as a modifier and a low asphalt content ratio, with a slow-cracking emulsifier to give it slow-cracking demulsification characteristics. A second-layer emulsion is prepared using SBS as a modifier and a higher asphalt content ratio than the first-layer emulsion, with a medium-cracking emulsifier to give it medium-cracking demulsification characteristics. The physical mechanism of this two-component emulsion system lies in actively constructing a gradient elastic modulus that continuously decreases along the depth direction. The first-layer emulsion, modified with rubber powder and with a low asphalt content, possesses low viscosity and slow-cracking characteristics, ensuring that the emulsion can penetrate deeply into the pores of the base layer, forming an anchoring layer that smoothly transitions to the high modulus of the base layer. The second-layer emulsion, modified with SBS and with a high asphalt content, possesses high viscosity and medium-cracking characteristics, ensuring that the emulsion forms a film quickly on the surface, forming a low-modulus, highly elastic stress-absorbing layer. By employing a gradient design to homogenize the interlayer shear stress, the risk of reflective cracking is significantly suppressed.

[0021] S400: Spray the first layer of emulsion evenly onto the base surface according to the first spraying amount. After spraying, start the industrial camera to continuously collect images of the sprayed surface. Calculate the current wetting index of the semi-rigid base in real time through the image color difference analysis algorithm. When the current wetting index reaches or exceeds the target wetting index, the spraying of the second layer of emulsion is initiated. Dynamic closed-loop control of the penetration state is achieved through an image color difference analysis algorithm. Traditional construction often uses timed control, that is, spraying the second layer of emulsion after a fixed waiting time. However, this method cannot adapt to changes in on-site temperature, humidity, wind speed, or fluctuations in substrate porosity, which can easily lead to insufficient or excessive penetration. This embodiment uses real-time calculation of the current wetting index to characterize the actual penetration depth of the emulsion. Subsequent actions are only triggered when the penetration reaches the expected target, thereby dynamically compensating for environmental deviations. This ensures that the first layer of penetration reaches the expected depth before the coating is applied, preventing the two layers of emulsion from mixing too early or solidifying and separating too late.

[0022] S500: Spray the second layer of emulsion evenly onto the base surface according to the second spraying amount. After spraying, continue to collect images of the sprayed surface through an industrial camera. Calculate the current demulsification index of the semi-rigid base in real time through an image color difference analysis algorithm. When the current demulsification index enters the preset semi-demulsification range, the crushed stone spreading operation is started, and the steel wheel roller is used for final compaction and locking to form an elastomeric asphalt under-sealing layer.

[0023] By calculating the demulsification index in real time, the semi-demulsification plateau period of the emulsion, which combines fluidity and viscosity, is accurately captured. At this point, spreading crushed stone can achieve the best embedding depth and bonding effect. Single-size crushed stone is spread onto the base course surface, and the crushed stone coverage is maintained within a range characterized by the exposed black state of the asphalt film on the base course surface through closed-loop regulation. Initial compaction is performed using a rubber-tired roller with low tire pressure, allowing the crushed stone particles to partially embed into the not-yet-fully-cured elastic asphalt film. After the emulsion is completely demulsified and cured, a steel-wheeled roller is used for final compaction and locking with a linear pressure higher than that of the rubber-tired roller, forming an elastomeric asphalt undersea layer.

[0024] Furthermore, using single-size crushed stone can provide a more stable macroscopic interlocking structure, and the asphalt film layer is in a black exposed state, that is, the crushed stone coverage is not 100%, but a part of the asphalt film layer is exposed. This provides a channel for the subsequent thermal fusion of the asphalt surface layer, forming a dual interlayer connection of mechanical interlocking and thermal fusion bonding.

[0025] Specifically, step S200 includes: S201: Obtain the average pore size and surface porosity of the semi-rigid base layer, as well as the dynamic viscosity, surface tension, and gel demulsification time of the first emulsion layer; obtain the average pore size and surface porosity of the semi-rigid base layer, as well as the dynamic viscosity, surface tension, and gel demulsification time of the first emulsion layer.

[0026] Specifically, the average pore size characterizes the microscopic channel scale of the porous medium in the base layer, and is usually determined in the laboratory by mercury intrusion porosimetry or hydrodynamic methods by drilling core samples. Its typical range is, for example, 30 μm to 60 μm. Surface porosity reflects the volume ratio of micropores on the surface of the base layer, and its typical range is, for example, 0.10 to 0.15. Dynamic viscosity characterizes the fluid resistance of the first layer emulsion during the penetration process. Since the first layer emulsion is modified with rubber powder and has a low asphalt content, its dynamic viscosity is usually controlled in a low range, for example, about 60 mPa·s to 120 mPa·s at 25°C. Surface tension characterizes the wetting and shrinkage ability of the emulsion on the capillary walls, and its typical range is, for example, 30 mN / m to 40 mN / m. Gel demulsification time characterizes the critical time for the emulsion to transform from a fluid state to a gel state after contacting the alkaline environment of the base layer. Since the first layer emulsion uses a slow-cracking emulsifier, this time is usually relatively long, for example, 15 minutes to 30 minutes. These parameters together constitute the input boundary conditions of the capillary permeation physical model.

[0027] S202: Substitute the average pore size, surface tension, dynamic viscosity and gel demulsification time into the capillary permeation equation to calculate the expected penetration depth of the first emulsion layer. The penetration of emulsions into porous media is essentially a dynamic wetting process driven by capillary forces and constrained by viscous resistance. In this embodiment, the modified Washburn equation is used as the core model of the capillary penetration equation. This equation describes the penetration depth as a function that is directly proportional to surface tension and average pore size, inversely proportional to dynamic viscosity, and directly proportional to the square root of the gel demulsification time. ; This represents the expected penetration depth of the first emulsion layer. The surface tension of the emulsion; The contact angle between the emulsion and the pore wall of the substrate; The average pore size of the base layer; The dynamic viscosity of the first emulsion layer; The gel breaking time of the first emulsion layer.

[0028] The gel demulsification time is introduced as a constraint parameter because slow-breaking emulsions do not remain in a purely fluid state throughout the penetration process. Once the gel demulsification time is reached, the emulsion viscosity increases sharply, and penetration essentially ceases. Therefore, the gel demulsification time defines the effective time window for penetration. This physical model allows for the accurate calculation of the expected penetration depth of the first layer of emulsion under specific substrate and emulsion characteristics. For example, the calculated expected penetration depth typically ranges from 3 mm to 10 mm, thus providing a solid physical basis for subsequent spray volume calculations.

[0029] S203: The first spraying amount of the first layer of emulsion is calculated by multiplying the expected penetration depth, surface porosity and preset effective filling coefficient.

[0030] The calculation logic for the first spray volume is based on the principle of volume conservation, that is, the total amount of sprayed emulsion should exactly fill the pore volume of the substrate surface within the expected penetration depth range. The calculation formula is as follows:

[0031] in, This is the initial spray volume of the first layer of emulsion; The density of the emulsion; This represents the expected penetration depth of the first emulsion layer. The surface porosity of the substrate; This is the effective fill factor.

[0032] The effective filling factor is an empirical constant less than 1. Its physical meaning is that the emulsion does not completely fill all micropores during penetration; some pores may be blocked by semi-closed air bubbles or microparticles. A typical value range is, for example, 0.6 to 0.8. By multiplying the expected penetration depth, surface porosity, and effective filling factor, and then combining this with the emulsion's density parameter, the required initial spray volume of the first layer of emulsion per unit area can be calculated.

[0033] S204: Based on the pre-calibrated curve of the elastic modulus of the second layer emulsion after curing and the asphalt content, the asphalt content required for the second layer emulsion is selected in reverse with the elastic modulus range of the target film layer, and then the second spraying amount of the second layer emulsion is calculated by combining it with the preset target film thickness. By pre-calibrating the elastic modulus curves of SBS-modified emulsified asphalt after curing with different asphalt contents in the laboratory, a one-to-one mapping relationship between asphalt content and elastic modulus can be established. During construction design, the target elastic modulus range required for the surface film layer is first determined based on the overall design goal of the gradient elastic modulus. For example, a typical target elastic modulus range is 500 MPa to 800 MPa. Then, the corresponding asphalt content that meets this modulus range is selected by reverse-engineering the curve. After determining the asphalt content, the target film thickness is calculated by combining it with the preset target film thickness, such as a typical target film thickness of 0.15 mm to 0.25 mm, and the density and solid content of the emulsion. It should be understood that although this embodiment illustrates the method of selecting asphalt content by reverse-engineering the modulus curve, in other embodiments, reverse-engineering can also be performed based on other mechanical properties of the stress-absorbing layer, such as low-temperature elongation or elastic recovery rate, as long as the mechanical logic of constructing the gradient modulus is satisfied.

[0034] S205: Determine and output the target wetting index corresponding to the expected penetration depth based on the pre-calibrated correspondence between the penetration depth and the surface wetting area ratio.

[0035] By conducting multiple penetration tests in the laboratory and calibrating the proportion of the base surface area covered by emulsion at different penetration depths, a quantitative correspondence between penetration depth and surface wetting area ratio can be established. After calculating the expected penetration depth in step S302, the target wetting index can be directly mapped using this correspondence. For example, when the expected penetration depth is 6.5 mm, the typical value of the target wetting index is 85%.

[0036] Specifically, step S400 includes: The current frame color image captured by the industrial camera is converted to the Lab color space. The first lightness channel is extracted, and its average value is calculated. Industrial cameras typically output images in the RGB color space, but the RGB channels are highly coupled and heavily influenced by the color temperature of the light source, making them unsuitable for quantifying the physical changes in surface brightness. The L channel in the Lab color space, i.e., the lightness channel, is independent of color information and can purely reflect the human eye's perception of brightness. Therefore, it is the best mathematical representation for characterizing the physical phenomenon of surface darkening caused by emulsion wetting. The average value of the lightness channel is the arithmetic mean of the values ​​of all pixels in the L channel of the current frame image. It macroscopically characterizes the overall brightness of the substrate surface in the current observation area.

[0037] The pre-calibrated first dry lightness value of the dry base surface and the baseline wetted lightness value when the emulsion is fully saturated are read. The baseline lightness value of the dry base surface refers to the average lightness value collected and calculated by an industrial camera when no emulsion has been sprayed and the lighting conditions meet the construction standards. Its typical range is, for example, 150 to 200, reflecting the high reflectivity characteristics of the dry gray-white cement-stabilized crushed stone surface. The baseline lightness value when the emulsion is fully saturated refers to the average lightness value measured in laboratory or field calibration tests when the emulsion has fully penetrated and completely covered the surface to form a dark wetted film. Its typical range is, for example, 20 to 50, reflecting the low reflectivity characteristics of the asphalt emulsion after absorbing light. It should be understood that these two baseline values ​​are not fixed constants, but need to be calibrated on-site before each construction according to the base material and lighting conditions to eliminate systematic deviations caused by different projects and different weather conditions.

[0038] The current wetting index is obtained by performing a normalized difference operation on the first dry lightness value, the reference wet lightness value, and the first lightness average value.

[0039] The ambient light at the construction site inevitably experiences slow drift or local abrupt changes. If we directly determine whether the absolute value of brightness is below a certain threshold, it is easy to cause false triggering due to changes in light. By using normalized difference calculation, we can reduce the impact of light change errors and thus improve the accuracy of the immersion index.

[0040] The calculation formula is: ; in, This represents the current penetration and infiltration index; The reference brightness value for the pre-calibrated dry substrate surface; This represents the average value of the brightness channels in the current frame image. This is the reference brightness value when the emulsion is fully saturated, as pre-calibrated.

[0041] The current brightness and darkness are mapped to a relative range of 0% to 100%, where 0 represents complete dryness and 100% represents complete wetting. The relative ratio calculation removes the influence of the absolute value of light intensity, so that the current wetting index is only related to the physical proportion of the surface covered by emulsion, thus remaining stable and reliable under fluctuating light conditions.

[0042] Specifically, step S400 also includes a cross-validation step: Automatic thresholding is performed on the first brightness channel, marking pixel regions with brightness values ​​below a preset threshold as wetted areas; the OTSU (Otsu method) automatic thresholding algorithm is used. The OTSU algorithm automatically calculates an optimal segmentation threshold based on the principle of maximizing the inter-class variance of the image brightness histogram, without requiring manual parameter setting. Pixels with brightness values ​​below this threshold are identified as locally darkened areas that have undergone wetting, while pixels with values ​​above the threshold are identified as dry areas that have not yet been wetted. This pixel-level fine segmentation can isolate the physical distribution of surface wetting from the background.

[0043] The number of pixels in the infiltrated area is counted, and the area ratio of the infiltrated area to the total number of pixels in the image is calculated. This ratio, converted from the number of pixels, directly reflects the percentage of the substrate surface covered by the emulsion. When the calculated area ratio is 85%, it means that 85% of the surface area within the observation field has been darkened and infiltrated.

[0044] The area ratio is cross-validated with the infiltration index obtained by normalized difference calculation, and the verification result is used as the basis for confirming the current infiltration index.

[0045] Based on cross-validation, the interference caused by specular reflection when local water film produces reflections can be reduced, and the interference from excessive wetness in local areas can also be reduced, thereby improving the accuracy of identifying the proportion of the wetted area in the base layer.

[0046] Furthermore, the specific logic of cross-validation can be as follows: the current infiltration index is confirmed to be valid only when the deviation between the normalized difference calculation infiltration index and the area ratio is less than a preset tolerance threshold, such as 5%; if the deviation is too large, it is determined that there is interference in the image, and the previous frame's confirmed value is maintained or an alarm is triggered to wait for the interference to be eliminated. Through this two-dimensional cross-validation, the image color difference analysis algorithm has extremely strong robustness in complex and ever-changing construction sites, ensuring the absolute reliability of the second layer of emulsion spraying.

[0047] Specifically, step S500 includes: The current frame color image captured by the industrial camera is converted to the Lab color space, the second lightness channel is extracted, and the average value of the second lightness channel is calculated. Similar to the calculation logic of the wetting index, the extraction of the demulsification index also relies on the lightness channel in the Lab color space, which is independent of color information. After the second layer of emulsion is sprayed, as the water evaporates and the asphalt particles condense, the surface undergoes a physical process from wet and reflective to matte and semi-transparent, and finally to solidified and glossy. This macroscopic change in lightness and darkness is accurately captured by the average value of the lightness channel, serving as a quantitative carrier of the evolution of the demulsification state.

[0048] Read the lowest brightness value of the image at the moment the second layer of emulsion is sprayed and the second dry brightness value of the pre-calibrated dry substrate surface; The minimum brightness value refers to the minimum average brightness value captured by the industrial camera when the second layer of emulsion has just been sprayed onto the surface. This is because the emulsion has the highest water content and a smooth, reflective water film forms on the surface. A typical range for this value is 20 to 40, representing the initial state where the emulsion is most wet and darkest. The baseline brightness value for the dry substrate surface is consistent with the baseline value calibrated in Example 3, representing the bright state when completely dry and without emulsion coverage. It should be understood that the minimum brightness value is not a fixed constant, but rather needs to be automatically captured and locked by the algorithm at the moment each second layer of emulsion is sprayed, to eliminate systematic deviations caused by slight fluctuations in emulsion concentration or spray thickness between different application batches.

[0049] Using the current average second brightness value, the lowest brightness value, and the second dry brightness value as inputs, a normalized ratio calculation is performed to obtain the current demulsification index.

[0050] The demulsification process is essentially a relative process of moisture removal and asphalt enrichment, rather than an absolute process of brightness restoration. Normalized ratio calculations are used. ; in, This represents the current demulsification index; This represents the average value of the brightness channels in the current frame image. The lowest brightness value for the image at the moment the second layer of emulsion is sprayed; The reference brightness value for the pre-calibrated dry substrate surface.

[0051] This calculation maps the physical process of demulsification to a relative range of 0% to 100%, where 0% represents the wettest state immediately after spraying and 100% represents complete demulsification and a dry state. This relative ratio calculation eliminates the influence of the absolute intensity of ambient light, ensuring that the demulsification index is only related to the degree of water evaporation and structural reorganization within the emulsion, thus maintaining stability and reliability even in construction environments with slow light drift.

[0052] Specifically, step S500 also includes: Calculate the first-order difference between the average brightness of the current frame and the previous frames. The first-order difference is the difference between the average brightness of the current frame and the average brightness of the previous frame or several previous frames. It characterizes the instantaneous rate of change in surface brightness, i.e., the speed of the dynamic evolution of the demulsification process. When the emulsion is in the rapid evaporation phase, the brightness increases rapidly, and the first-order difference is relatively large. When the emulsion enters the semi-demulsification plateau phase, the rate of water removal slows down, asphalt particles form a semi-transparent, matte surface, the increase in brightness stops significantly, and the first-order difference shrinks sharply to near zero.

[0053] When the current demulsification index enters the preset semi-demulsification range, and the first-order difference value corresponding to multiple consecutive frames is lower than the preset brightness change threshold, the second layer of emulsion is determined to have entered the semi-demulsification state and the gravel spreading is triggered.

[0054] The preset semi-demulsification interval is a numerical range set based on a normalized ratio, typically ranging from 0.4 to 0.6, representing a demulsification rate of 40% to 60%. The core mechanical mechanism for capturing this semi-demulsification plateau period, rather than waiting for complete demulsification before spreading the crushed stone, is as follows: In a fully demulsified state, the emulsion has solidified and lost its viscosity, making it difficult for the crushed stone to embed and easily causing it to float on the surface, forming a loose layer. However, if spread immediately after spraying, the emulsion's excessive fluidity causes the crushed stone to sink excessively into the film layer or even contact the base layer, losing its macroscopic interlocking function. Only during the semi-demulsification plateau period, when the emulsion possesses both sufficient fluidity to wet the crushed stone surface and enough viscosity to support the stone and partially embed it to approximately 1 / 4 to 1 / 3 of its particle size depth, can the most stable interlocking structure be formed when spread and combined with initial compaction.

[0055] Specifically, when the current demulsification index enters the preset semi-demulsification range, the operation of spreading crushed stone is initiated, and a steel wheel roller is used for final compaction and locking to form an elastomeric asphalt underseal, which includes: Single-size crushed stone is spread on the surface of the semi-rigid base course, and the crushed stone coverage is maintained within the range where the asphalt film layer on the base course surface is exposed black. A rubber-tired roller is used to perform initial compaction with low tire pressure. The spread crushed stone is hard gravel with a single size.

[0056] Single-size crushed stone refers to aggregate with an extremely narrow particle size distribution and almost no fine filler, such as basalt or granite gravel with a typical particle size range of 3mm to 8mm or 5mm to 10mm. This single-size design ensures the formation of a uniform macroscopic interlocking skeleton between the crushed stones, avoiding the rigidity of the skeleton structure caused by fine filler, thus preserving the elastic deformation space required for stress buffering. Methods for maintaining crushed stone coverage include: real-time acquisition of the black-and-white pixel ratio signal of the base surface image using photoelectric sensors, and adjusting the opening of the spreading gate based on the feedback of the signal.

[0057] Furthermore, the "exposed black state" refers to a situation where the aggregate coverage is not 100%, allowing some exposed asphalt film to form a thermal fusion channel during subsequent asphalt surface layer paving. When the high-temperature asphalt mixture is laid on the seal layer surface, the exposed elastic asphalt film melts upon heating and bonds thermally with the newly laid surface asphalt, while the aggregate provides mechanical interlocking resistance. This dual interlayer connection mode of mechanical interlocking and thermal fusion bonding offers significantly higher shear fatigue resistance than either a single mechanical interlocking or a single thermal fusion bonding method.

[0058] After the emulsion has completely demulsified and solidified, a steel wheel roller is used to apply a higher linear pressure than a rubber-tired roller to lock the elastomer asphalt undersealing layer.

[0059] Furthermore, a rubber-tired roller is first used to perform initial compaction with low tire pressure, so that the crushed stone particles are partially embedded in the elastic asphalt film layer that has not yet fully cured. After the emulsion is completely demulsified and cured, a steel-wheeled roller is used to perform final compaction and locking with a linear pressure higher than that of the rubber-tired roller, forming an elastomeric asphalt undersea layer.

[0060] Specifically, in step S400, when the first layer of emulsion is sprayed, the construction vehicle travels at a first preset speed; in step S600, the rubber-tired roller performs initial compaction at a second preset speed lower than the construction vehicle's travel speed, and the steel-wheeled roller uses static pressure for final compaction and locking. The embedding process of the crushed stone in a semi-demulsified state is a fluid-structure interaction process that requires precise control. Using a composite rate for compaction can avoid the situation where excessive stress concentration during single high-pressure compaction leads to the crushed stone puncturing the asphalt film layer.

[0061] Furthermore, in this embodiment, a differential compaction strategy of low-pressure initial embedment and high-pressure final compaction is adopted. During the initial embedment compaction, the tire inflation pressure of the rubber-tired roller is usually controlled in the low-pressure range of 0.3MPa to 0.5MPa. This pressure range allows the crushed stone to slowly sink into the viscous asphalt film layer to a depth of about 1 / 4 to 1 / 3 of the particle size under its own weight and the kneading action of low pressure, which ensures sufficient embedment and anchoring depth while avoiding the crushing and puncturing of the film layer.

[0062] Simultaneously, the rubber-tired roller travels at a second preset speed lower than the construction vehicle's speed; for example, when the construction vehicle's speed is 4 km / h, the rubber-tired roller's speed is 3 km / h. This speed difference ensures sufficient coverage and kneading time for each section of the compaction operation. After the emulsion has completely broken down and solidified, and the elastic film layer has recovered sufficient shear strength, a double-drum roller is used for final compaction and locking. The linear pressure of the drum roller is usually higher than that of the rubber-tired roller, for example, a typical linear pressure of 25 N / mm. Static pressure is used to finally lock and position the embedded crushed stone, eliminating minor local displacements and forming a stable interlocking skeleton. It should be understood that although this embodiment lists a combination of rubber-tired and drum rollers, other compaction combinations can also be applied in other embodiments, as long as the mechanical logic of low-pressure initial embedding and kneading and high-pressure final locking is satisfied.

[0063] After construction is completed and a set curing time is set, core samples are drilled from the construction section. The elastic modulus distribution curve of the seal layer interface is measured along the depth direction. The measured curve is compared with the gradient elastic modulus distribution determined by the expected penetration depth, following a closed-loop construction process of design-construction-verification. Specifically, the set curing time is usually 24 to 48 hours. After the emulsified asphalt has fully cured and formed strength, 100mm diameter core samples are drilled from randomly selected construction sections. In the laboratory, using micron-level continuous modulus testing technology, the elastic modulus is measured point by point along the depth direction of the core sample from the surface asphalt film layer through the penetration anchor layer to the base matrix, and the measured modulus distribution curve is plotted. Subsequently, this measured curve is compared with the gradient elastic modulus distribution design curve determined by the penetration-modulus mapping algorithm, and the standardized root mean square error of the two is calculated.

[0064] If the error is less than the preset threshold, such as 8%, the gradient modulus forming quality of this construction is deemed qualified, and the physical structure accurately conforms to the design expectations. If the error exceeds the threshold, it indicates that fluctuations in the on-site environment or deviations in construction parameters have caused the modulus distribution to deviate, and the deviation data needs to be fed back to the algorithm model for parameter iteration and optimization.

[0065] Example 2: Please refer to Figure 3 This invention also provides a lower sealing layer construction system based on simultaneous tack coat curing of elastomeric asphalt, the construction system comprising: Data acquisition module 10: This module acquires the surface texture depth and average pore size parameters of the semi-rigid base course after paving and compaction. Specifically, the data acquisition module 10 can be integrated into the front-end detection system of the construction vehicle, such as including a laser texture depth gauge and a micro-drilling sampler, or communicate with a remote laboratory data terminal. The function of this module is to provide physical boundary conditions for subsequent parameter pre-calculation modules, ensuring the accuracy of the algorithm input source.

[0066] Data calculation module 20: is used to output the asphalt content ratio and first spraying amount of the first layer emulsion, the asphalt content ratio and second spraying amount of the second layer emulsion, and the target wetting index based on the surface texture depth and average pore size parameters of the base layer through a permeability-modulus mapping algorithm, wherein the asphalt content ratio of the first layer emulsion is lower than the asphalt content ratio of the second layer emulsion. The data calculation module 20 is used to acquire the surface texture depth and average pore size parameters of the substrate, the viscosity parameters and demulsification time parameters of the first emulsion layer, run the penetration-modulus mapping algorithm, and output the target spraying volume of the first emulsion layer, the target spraying volume of the second emulsion layer, and the target wetting index. Specifically, the data calculation module 20 is usually undertaken by an on-board industrial control computer or a cloud server. This module receives the pore characteristic data transmitted by the substrate parameter acquisition module, combines it with the fluid characteristic data fed back by the two-component emulsion supply module, and directly outputs the control commands for the target spraying volume and the target wetting index through physical model mapping calculation. The target spraying volume is then sent to the pumping and metering system of the two-component emulsion supply module, and the target wetting index is sent to the image processing and control module as a trigger reference threshold.

[0067] The dual-emulsion preparation module 30 is used to prepare a first-layer emulsion based on the asphalt content ratio of the first-layer emulsion, using rubber powder as a modifier and combining it with a slow-cracking emulsifier; and to prepare a second-layer emulsion based on the asphalt content ratio of the second-layer emulsion, using SBS as a modifier and combining it with a medium-cracking emulsifier. It includes independent storage tanks and independent spraying pipelines. The first independent storage tank contains the first-layer emulsion prepared with rubber powder as a modifier, a low asphalt content ratio, and a slow-cracking emulsifier. The second independent storage tank contains the second-layer emulsion prepared with SBS as a modifier, a higher asphalt content ratio than the first-layer emulsion, and a medium-cracking emulsifier. Specifically, the physical mechanism for using independent storage tanks and independent spraying pipelines instead of a single tank for mixed spraying is that the demulsification rates and rheological properties of the first and second-layer emulsions differ significantly. If premixed in the storage tank, the slow-cracking and medium-cracking emulsifiers will chemically interfere, leading to emulsion system instability and demulsification failure. Independent storage tank designs typically include separate insulated mixing devices and pumping metering systems. The first layer of spraying piping is located at the front end of the construction vehicle's travel direction, and the second layer of spraying piping is located at the rear end, maintaining spatial distance between them to ensure sufficient physical penetration time for the first layer of emulsion before receiving the coating of the second layer. It should be understood that although this embodiment illustrates a front-to-back piping design, other embodiments may also employ a solenoid valve group design with the same spray bar but time-division control, as long as the independent spraying logic of the two emulsions in both physical space and time sequence is satisfied.

[0068] First emulsification module 40: used to uniformly spray the first layer of emulsion onto the base surface according to the first spraying amount, and after spraying, start an industrial camera to continuously collect images of the sprayed surface, and calculate the current wetting index of the semi-rigid base in real time through an image color difference analysis algorithm; When the current wetting index reaches or exceeds the target wetting index, the spraying of the second layer of emulsion is initiated. The second emulsification module 50 is used to uniformly spray the second layer of emulsion onto the surface of the base layer according to the second spraying amount. After spraying, it continues to collect images of the sprayed surface through an industrial camera and calculates the current demulsification index of the semi-rigid base layer in real time through an image color difference analysis algorithm. The first emulsification module 40 and the second emulsification module 50 acquire images of the substrate surface continuously after the first and second layers of emulsion are sprayed, using an industrial camera mounted at the rear of the construction vehicle. The camera frame rate is typically set to 10fps to 20fps to ensure a continuous and uninterrupted stream of image data at construction speeds of 3km / h to 5km / h. It should be understood that while this embodiment illustrates a single industrial camera arrangement, in other embodiments, multi-camera arrays or line-scan cameras can be used to expand the field of view or eliminate shadow interference, as long as the function of real-time continuous acquisition of surface brightness changes is satisfied.

[0069] After the first layer of emulsion is sprayed, the current wetting index is calculated in real time, and a first trigger signal is output when the current wetting index reaches or exceeds the target wetting index to start the spraying of the second layer of emulsion; after the second layer of emulsion is sprayed, the current demulsification index is calculated in real time, and a second trigger signal is output when the current demulsification index enters the preset semi-demulsification range to start the gravel spreading.

[0070] When the current demulsification index enters the preset semi-demulsification range, the crushed stone spreading operation is initiated, and the steel wheel roller performs final compaction locking to form an elastomeric asphalt undersealing layer. After receiving the second trigger signal, the crushed stone spreader spreads single-size crushed stone onto the base course surface and maintains the crushed stone coverage within a range characterized by the exposed black state of the asphalt film on the base course surface through closed-loop regulation. The rubber-tired roller performs initial compaction with low-pressure tires, and the steel wheel roller performs final compaction locking with a linear pressure higher than that of the rubber-tired roller after the emulsion has completely demulsified and solidified.

[0071] Through the coordinated operation of the aforementioned modules, the system in this embodiment materializes the design of the two-component gradient emulsion system and the dynamic closed-loop control algorithm into a specific construction equipment system, realizing the automation and intelligence of integrated construction of sealing layer under simultaneous permeable curing. The data flow and control flow between the modules are closely integrated, forming an inseparable hardware evidence chain from base layer parameter detection to precise emulsion spraying, from real-time image recognition to instantaneous mechanical response, ensuring the accurate formation of the gradient elastic modulus interface structure.

[0072] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, etc.

[0073] Furthermore, the embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for constructing a lower sealing layer based on simultaneous tack coat curing of elastomeric asphalt, characterized in that, The construction method includes: After the semi-rigid base course is laid and compacted, the surface texture depth and average pore size parameters of the semi-rigid base course are obtained. Based on the surface texture depth and average pore size parameters of the base layer, the bitumen content ratio and first spraying amount of the first layer emulsion, the bitumen content ratio and second spraying amount of the second layer emulsion, and the target wetting index are output through the permeability-modulus mapping algorithm, wherein the bitumen content ratio of the first layer emulsion is lower than that of the second layer emulsion. Based on the asphalt content ratio of the first emulsion, a first emulsion is prepared using rubber powder as a modifier and combined with a slow-cracking emulsifier. Based on the asphalt content ratio of the second emulsion, a second emulsion is prepared using SBS as a modifier and combined with a medium-cracking emulsifier. The first layer of emulsion is evenly sprayed onto the base surface according to the first spraying amount. After spraying, an industrial camera is started to continuously collect images of the sprayed surface. The current wetting index of the semi-rigid base is calculated in real time through an image color difference analysis algorithm. When the current wetting index reaches or exceeds the target wetting index, the spraying of the second layer of emulsion is initiated. The second layer of emulsion is evenly sprayed onto the base surface according to the second spraying amount. After spraying, the sprayed surface image is continuously collected by an industrial camera, and the current demulsification index of the semi-rigid base is calculated in real time by an image color difference analysis algorithm. When the current demulsification index enters the preset semi-demulsification range, the crushed stone spreading operation is started, and the steel wheel roller is used for final compaction and locking to form an elastomeric asphalt under-sealing layer.

2. The method for constructing the lower sealing layer according to claim 1, characterized in that, The step of outputting the asphalt content ratio and first spraying amount of the first emulsion, the asphalt content ratio and second spraying amount of the second emulsion, and the target wetting index based on the surface texture depth and average pore size parameters of the base layer using a permeability-modulus mapping algorithm includes: The average pore size and surface porosity of the semi-rigid substrate, as well as the dynamic viscosity, surface tension, and gel demulsification time of the first emulsion layer, are obtained. The average pore size, surface tension, dynamic viscosity, and gel demulsification time are substituted into the capillary permeation equation for calculation to obtain the expected penetration depth of the first emulsion layer. The first spraying amount of the first layer of emulsion is calculated by multiplying the expected penetration depth, surface porosity and preset effective filling coefficient. Based on the pre-calibrated curve of the elastic modulus of the second emulsion after curing and the asphalt content, the asphalt content required for the second emulsion is selected in reverse with the elastic modulus range of the target film layer, and then the second spraying amount of the second emulsion is calculated by combining it with the preset target film thickness. Based on the pre-defined correspondence between penetration depth and surface wetting area ratio, the target wetting index corresponding to the expected penetration depth is determined and output.

3. The method for constructing the lower sealing layer according to claim 1, characterized in that, The process of uniformly spraying a first layer of emulsion onto the substrate surface at the first spraying amount, and then continuously acquiring images of the sprayed surface using an industrial camera after spraying, and calculating the current wetting index of the semi-rigid substrate in real time using an image color difference analysis algorithm includes: Convert the current frame color image captured by the industrial camera into the Lab color space, extract the first brightness channel, and calculate the average value of the first brightness channel; Read the first dry lightness value of the pre-calibrated dry substrate surface and the reference wetted lightness value when the emulsion is fully wetted; The current wetting index is obtained by performing a normalized difference operation on the first dry lightness value, the reference wet lightness value, and the first lightness average value.

4. The method for constructing the lower sealing layer according to claim 3, characterized in that, The process of uniformly spraying a first layer of emulsion onto the substrate surface at the first spraying amount, and then continuously acquiring images of the sprayed surface using an industrial camera after spraying, and calculating the current wetting index of the semi-rigid substrate in real time using an image color difference analysis algorithm, further includes: Automatic thresholding is performed on the first brightness channel, and pixel regions with brightness values ​​lower than a preset segmentation threshold are marked as immersion regions. The number of pixels in the infiltrated region is counted, and the area ratio of the number of pixels in the infiltrated region to the total number of pixels in the image is calculated. The area ratio is cross-validated with the infiltration index obtained by normalized difference calculation, and the verification result is used as the basis for confirming the current infiltration index.

5. The method for constructing the lower sealing layer according to claim 1, characterized in that, The process of uniformly spraying a second layer of emulsion onto the substrate surface at the second spraying rate, and then continuously acquiring images of the sprayed surface using an industrial camera, and calculating the current demulsification index of the semi-rigid substrate in real time using an image color difference analysis algorithm, includes: The current frame color image captured by the industrial camera is converted into the Lab color space, the second brightness channel is extracted, and the average value of the second brightness channel is calculated. Read the lowest brightness value of the image at the moment the second layer of emulsion is sprayed and the second dry brightness value of the pre-calibrated dry substrate surface; Using the current average second brightness value, the lowest brightness value, and the second dry brightness value as inputs, a normalized ratio calculation is performed to obtain the current demulsification index.

6. The method for constructing the lower sealing layer according to claim 5, characterized in that, The process of uniformly spraying a second layer of emulsion onto the substrate surface at the second spraying rate, and then continuously acquiring images of the sprayed surface using an industrial camera, and calculating the current demulsification index of the semi-rigid substrate in real time using an image color difference analysis algorithm, further includes: Calculate the first-order difference between the average brightness values ​​of the current frame and the previous frame; When the current demulsification index enters the preset semi-demulsification range, and the first-order difference value corresponding to multiple consecutive frames is lower than the preset brightness change threshold, the second layer of emulsion is determined to have entered the semi-demulsification state and the gravel spreading is triggered.

7. The method for constructing the lower sealing layer according to claim 6, characterized in that, The preset semi-delay interval ranges from 0.4 to 0.

6.

8. The method for constructing the lower sealing layer according to claim 1, characterized in that, When the current demulsification index enters the preset semi-demulsification range, the crushed stone spreading operation is initiated, and a steel wheel roller is used for final compaction and locking to form an elastomeric asphalt underseal layer, including: Single-size crushed stone is spread on the surface of the semi-rigid base course, and the crushed stone coverage is maintained within the range where the asphalt film layer on the base course surface is exposed black. A rubber-tired roller is used to perform initial compaction with low tire pressure. After the emulsion has completely demulsified and solidified, a steel wheel roller is used to apply a higher linear pressure than a rubber-tired roller to lock the elastomer asphalt undersealing layer.

9. The method for constructing the lower sealing layer according to claim 1, characterized in that, When the current demulsification index enters the preset semi-demulsification range, the crushed stone spreading operation is initiated, and a steel wheel roller is used for final compaction and locking to form an elastomeric asphalt underseal layer, including: During the gravel spreading operation, a photoelectric sensor is used to collect the black-and-white pixel ratio signal of the base surface image in real time, and the opening of the spreading gate is adjusted according to the feedback of the signal.

10. A sub-sealing construction system based on simultaneous tack coat curing of elastomeric asphalt, characterized in that, The construction system includes: Data acquisition module: used to acquire the surface texture depth and average pore size parameters of the semi-rigid base course after the semi-rigid base course is laid and compacted; Data calculation module: used to output the bitumen content ratio and first spraying amount of the first layer emulsion, the bitumen content ratio and second spraying amount of the second layer emulsion, and the target wetting index based on the surface texture depth and average pore size parameters of the base layer through the permeability-modulus mapping algorithm, wherein the bitumen content ratio of the first layer emulsion is lower than the bitumen content ratio of the second layer emulsion. Dual-emulsion preparation module: used to prepare the first emulsion by using rubber powder as a modifier and combining it with a slow-cracking emulsifier according to the asphalt content ratio of the first emulsion; and to prepare the second emulsion by using SBS as a modifier and combining it with a medium-cracking emulsifier according to the asphalt content ratio of the second emulsion. First emulsification module: used to uniformly spray the first layer of emulsion onto the base surface according to the first spraying amount, and after spraying, start the industrial camera to continuously collect images of the sprayed surface, and calculate the current wetting index of the semi-rigid base in real time through the image color difference analysis algorithm; When the current wetting index reaches or exceeds the target wetting index, the spraying of the second layer of emulsion is initiated. The second emulsification module is used to uniformly spray the second layer of emulsion onto the surface of the base layer according to the second spraying amount. After spraying, it continues to collect images of the sprayed surface through an industrial camera and calculates the current demulsification index of the semi-rigid base layer in real time through an image color difference analysis algorithm. When the current demulsification index enters the preset semi-demulsification range, the crushed stone spreading operation is started, and the steel wheel roller is used for final compaction and locking to form an elastomeric asphalt under-sealing layer.

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