Method and device for controlling the quality of heating and mixing of recycled asphalt mixture

Abstract

The application discloses a quality control method and device for heating and mixing of regenerated asphalt mixture, and the quality control method comprises pretreatment of waste asphalt, graphene modification of new asphalt, heating and mixing operation, monitoring of mixing data, establishment of a fusion degree index of new and old asphalts and mixing process control, and the device comprises a mixing device platform, a RAP pretreatment module, a new asphalt modification module, a main mixing module, a fluorescence monitoring module, an electrical impedance monitoring module and a data processing and control module; the dispersion uniformity of new and old asphalts during heating and mixing is simultaneously, independently and non-contactly obtained by using the fluorescence characteristics of SBS modifier and the electrical impedance characteristics of graphene modifier, the hysteresis of traditional manual visual inspection and sampling detection and other methods is overcome, and real-time quantitative evaluation and self-adaptive control of mixing quality are realized.

Description

Technical Field

[0001] This invention relates to the field of road engineering materials technology, and in particular to a method and apparatus for quality control of heated mixing of recycled asphalt mixtures. Background Technology

[0002] Asphalt pavement recycling technology involves heating recycled waste asphalt pavement material (RAP) and then remixing it with new aggregates, new asphalt, or recycling agents to form recycled asphalt mixture (RAM) for pavement construction. Asphalt pavement recycling technology not only significantly reduces raw material consumption and waste emissions but also reduces energy consumption and carbon emissions, resulting in significant economic and environmental benefits.

[0003] During the production of RAM (Range Rubber) particles, the waste asphalt on the surface of the RAP (Range Rubber) particles needs to achieve uniform diffusion and component fusion at the microscopic level with the new asphalt (or recycling agent) during the heating and mixing stage. The negative impacts of insufficient fusion between new and old asphalt include: 1) Insufficient performance recovery of the waste asphalt, resulting in significantly lower-than-expected overall mechanical properties, adhesion, and durability of the RAM; 2) Weak interface zones with poor physicochemical bonding between the waste and new asphalt, which easily become stress concentration points and seepage channels; 3) Insufficient RAM performance will lead to rutting, potholes, internal voids, and other defects, shortening the pavement's service life. Overheating the mixing process to overcome insufficient fusion also negatively impacts RAM performance, potentially leading to further degradation of the waste asphalt's performance, aggregate breakage causing gradation deterioration, and reduced economic efficiency and construction effectiveness.

[0004] Current quality control of RAM (Roasted Asphalt) heating and mixing mainly relies on the following methods: 1) Before mixing, a fixed mixing temperature, time, and stirring intensity are preset based on experience or test results; 2) During mixing, the quality of RAM is judged by visual observation of characteristics such as color and flowability; 3) After mixing, the physical and mechanical properties of RAM are obtained through laboratory sampling and testing. However, different batches of RAP (Roasted Asphalt) have different aging degrees and aggregate characteristics. The fixed process parameter control method cannot be adjusted in real time according to the characteristics of RAP, the type of new asphalt, and the real-time status of the heating and mixing process. Secondly, the control method of visual judgment has the defects of strong subjectivity, low accuracy, and low efficiency, and cannot accurately assess the degree of fusion between new and old asphalt. Furthermore, the control method of laboratory sampling and testing has obvious lag and cannot provide real-time feedback for the ongoing mixing process.

[0005] Existing technologies lack a method and device for quantitatively calculating the degree of integration between new and old asphalt through monitoring, thereby providing real-time feedback for ongoing RAM mixing operations. This makes it difficult to meet the demands of the heated mixing operations of recycled asphalt mixtures for high efficiency, intelligence, and precision. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention applies for a method and apparatus for quality control of heated mixing of recycled asphalt mixtures. By integrating multi-physics field monitoring and adaptive control, it solves the problems of lagging quality control and large errors caused by human intervention in traditional mixing processes, providing technical support for the high-performance production of recycled asphalt mixtures (RAM).

[0007] A method for quality control of heated mixing of recycled asphalt mixtures includes the following steps:

[0008] S1. Pretreatment of waste asphalt:

[0009] The recycled waste asphalt pavement material (RAP) is thoroughly crushed and then mixed with a styrene-butadiene-styrene block copolymer modifier (SBS modifier) ​​and heated to ensure that the SBS modifier is uniformly dispersed in the RAP, thus obtaining pretreated RAP. The fluorescent properties of the styrene segments in the SBS modifier enable the pretreated RAP to emit blue-green fluorescence under ultraviolet excitation light.

[0010] S2, Graphene modification of new asphalt:

[0011] Graphene modifiers are added to new asphalt, and the graphene modifiers are uniformly dispersed in the new asphalt through heating and shear dispersion processes to obtain graphene-modified new asphalt.

[0012] S3. Heating and mixing operation:

[0013] The pretreated RAP and the graphene-modified new asphalt are heated and mixed to obtain RAM;

[0014] S4. Monitoring of mixing data:

[0015] The heating and mixing area was evenly divided into multiple cubic grids of the same size; the fluorescence of the pretreated RAP was excited by an ultraviolet excitation light source, and the fluorescence intensity signal was acquired using a high-temperature resistant high-speed camera and a bandpass filter, thereby obtaining... t Time of the first n The fluorescence intensity value of the preprocessed RAP within a cubic grid. F ( n , t The graphene-modified asphalt is subjected to an alternating voltage through an annular electrode installed on the inner wall of the mixing device, and the electrical impedance value is obtained through an electrical impedance analyzer, thereby obtaining... t Time of the first n The electrical impedance value of the graphene-modified new asphalt within a cubic grid. Z ( n , t );

[0016] S5. Establishment of an index for the degree of integration between new and old asphalt:

[0017] Based on fluorescence intensity value F ( n , t )calculate t Fluorescence distribution uniformity index at time U F As shown in the following formula:

[0018]

[0019] in, s F The standard deviation of the fluorescence intensity value. m F This represents the average fluorescence intensity value; U F The value reflects the dispersion of fluorescence intensity data. As the degree of fusion between new and old asphalt increases, the spatial distribution of fluorescence intensity data tends to be more consistent. U F The larger the value, the more uniform the RAP distribution after preprocessing;

[0020] Based on electrical impedance value Z ( n , t )calculate t Uniformity index of impedance distribution at time t U Z As shown in the following formula:

[0021]

[0022] in, s Z The standard deviation of the electrical impedance value. m Z This represents the average value of the electrical impedance. U Z Reflecting the dispersion of electrical impedance data, as the degree of fusion between new and old asphalt increases, the spatial distribution of electrical impedance data tends to be more consistent. U Z The larger the value, the more uniform the distribution of the new asphalt after graphene modification;

[0023] Indicators of the degree of integration between new and old asphalt K Satisfy the following expression:

[0024]

[0025] in, α and β As sF and s Z The weight parameters change dynamically based on the value of the parameter, satisfying the following conditions: α + β =1, and α Satisfy the following expression:

[0026]

[0027] The threshold value for the degree of fusion between new and old asphalt that enables RAM performance to meet requirements was obtained through experiments.

[0028] K min That is, when K ≥ K min The degree of fusion between the old and new asphalt is determined to meet the requirements.

[0029] S6. Mixing process control:

[0030] when K < K min If the degree of fusion between the old and new asphalt is determined to be insufficient, the remaining mixing time Δ of the mixing unit will be reduced. T The control is shown in the following formula:

[0031]

[0032] in, c The gain parameter is used to control the gain, and its value ranges from [0.5, 2]. c The value decreases as the heating and mixing process progresses.

[0033] A recycled asphalt mixture heating and mixing device is used to implement the quality control method for the heating and mixing of the recycled asphalt mixture, including a mixing device platform, a RAP pretreatment module, a new asphalt modification module, a main mixing module, a fluorescence monitoring module, an electrical impedance monitoring module, and a data processing and control module.

[0034] The mixing plant platform includes a material lifting device, a chute, a mixing plant support frame, a mobile batching trolley, and a mobile batching track. The mixing plant support frame is constructed from steel components to form the platform. The material lifting device is located on both sides of the mixing plant support frame and is used to transport RAP or new asphalt to a higher position, and then pour it into the mobile batching trolley via the chute located at the top of the material lifting device. The mobile batching trolley is placed on the mobile batching track and can move horizontally.

[0035] The RAP pretreatment module includes a RAP feed hopper, an SBS modifier quantitative dispensing device, and a first heating and mixing tank. The RAP feed hopper is located below the moving batching track and above the first heating and mixing tank, and is used to receive RAP from the moving batching trolley. The SBS modifier quantitative dispensing device is located above the first heating and mixing tank, and is used to store and quantitatively dispense SBS modifier into the first heating and mixing tank. The first heating and mixing tank has built-in spiral stirring blades and an electric heating device, which, through heating and mixing operations, ensures that the SBS modifier is uniformly dispersed in the RAP.

[0036] The new asphalt modification module includes a graphene storage tank, a high-speed shear disperser, and a second heated mixing tank. The graphene storage tank is located above the second heated mixing tank and is used to store and quantitatively deliver graphene modifiers into the second heated mixing tank. The second heated mixing tank has built-in spiral stirring blades and an electric heating device. The high-speed shear disperser generates strong shear force through high-speed rotation. The high-speed shear disperser and the second heated mixing tank, through heating and shear dispersion processes, ensure that the graphene modifiers are uniformly dispersed in the new asphalt.

[0037] The main mixing module includes a feed hopper, a batching and weighing device, a preheating box, a mixing device, a third heated mixing tank, and a discharge port. The feed hopper is located below the first and second heated mixing tanks and is used to receive pretreated RAP or graphene-modified new asphalt. The batching and weighing device is located below the feed hopper and is used to weigh the pretreated RAP or graphene-modified new asphalt and transport it to the preheating box. The preheating box is located below the batching and weighing device and is used to preheat the pretreated RAP and the graphene-modified new asphalt. The third heated mixing tank is located below the preheating box and above the discharge port, and is equipped with the mixing device inside for mixing the pretreated RAP and the graphene-modified new asphalt.

[0038] The fluorescence monitoring module includes an ultraviolet excitation light source and a high-temperature resistant high-speed camera, both of which are installed on the side wall of the third heating mixing tank; the ultraviolet excitation light source uses an LED lamp capable of exciting ultraviolet light; the high-temperature resistant high-speed camera is used to capture the fluorescence signal of RAP in real time and is equipped with a bandpass filter to ensure the accuracy of fluorescence signal acquisition.

[0039] The electrical impedance monitoring module includes a ring electrode and an electrical impedance analyzer, both installed on the side wall of the third heating mixing tank and evenly distributed along the circumference; the electrical impedance monitoring module and the fluorescence monitoring module are alternately distributed to avoid mutual interference; the ring electrode is used to apply an alternating voltage to the third heating mixing tank; the electrical impedance analyzer is used to acquire the electrical impedance data of the graphene-modified new asphalt;

[0040] The data processing and control module is integrated into an embedded computer. It is used to receive and process the data acquired by the fluorescence monitoring module and the electrical impedance monitoring module, and to control the working parameters of the mixing device according to the degree of fusion between new and old asphalt.

[0041] Compared with existing technologies, the beneficial effects of this invention are as follows: Existing technologies lack methods that combine magnetic tracer materials, quality monitoring of recycled asphalt pavement construction, and intelligent data processing. Addressing the problems of lagging quality control and large errors due to manual intervention in the heating and mixing of recycled asphalt mixtures in existing technologies, this invention proposes a method and device for quality control of heated and mixed recycled asphalt mixtures. This quality control method includes pretreatment of waste asphalt, graphene modification of new asphalt, heating and mixing operations, monitoring of mixing data, establishment of indicators for the degree of fusion between new and old asphalt, and control of the mixing process. The device includes a mixing platform, a RAP pretreatment module, a new asphalt modification module, a main mixing module, a fluorescence monitoring module, an impedance monitoring module, and a data processing and control module. Utilizing the fluorescence characteristics of SBS modifiers and the impedance characteristics of graphene modifiers, multi-physics field collaborative monitoring is achieved through ultraviolet excitation and a ring electrode to obtain the fluorescence intensity of waste asphalt mixtures and the impedance data of new asphalt. This allows for simultaneous, independent, and non-contact acquisition of the dispersion uniformity of new and old asphalt during heating and mixing. This method overcomes the limitations of traditional manual visual inspection and sampling methods, as well as the inability of a single method to simultaneously assess the dispersion of new and old asphalt, thus preventing the quantification of the interface fusion degree. Both SBS and graphene modifiers are asphalt modifiers that effectively improve the various physical and mechanical properties of RAM (Rubber Asphalt Mixture). Their application in monitoring the dispersion of new and old asphalt enhances RAM product performance while simultaneously achieving sensing functionality. Based on real-time monitoring data, fluorescence distribution uniformity index and electrical impedance distribution uniformity index are calculated, establishing a quantitative index of the fusion degree between new and old asphalt, directly reflecting the microscopic fusion degree and forming a scientific evaluation system. The remaining mixing time is automatically adjusted in real-time based on the fusion degree index, avoiding insufficient fusion or overheating caused by fixed parameters, achieving dynamic adaptive control of the heating and mixing process. Modular device design enables automated production, heating and mixing process monitoring, and adaptive control, meeting the demands for high efficiency, intelligence, and precision in the heating and mixing of recycled asphalt mixtures. Attached Figure Description

[0042] Figure 1 This is a flowchart of the method for controlling the quality of heated mixing of recycled asphalt mixtures according to an embodiment of the present invention;

[0043] Figure 2 This is a system module diagram of the recycled asphalt mixture heating and mixing device shown in an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the recycled asphalt mixture heating and mixing device shown in an embodiment of the present invention;

[0045] Reference numerals: 1-Mixing device platform, 11-Feeding equipment, 12-Slipper, 13-Mixing station support, 14-Mobile batching trolley, 15-Mobile batching track, 2-RAP pretreatment module, 21-RAP feed hopper, 22-SBS modifier quantitative feeding device, 23-First heating mixing tank, 3-New asphalt modification module, 31-Graphene storage tank, 32-High-speed shear disperser, 33-Second heating mixing tank, 4-Main mixing module, 41-Feed hopper, 42-Batching weighing device, 43-Preheating box, 44-Mixing device, 45-Third heating mixing tank, 46-Discharge port, 5-Fluorescence monitoring module, 51-Ultraviolet excitation light source, 52-High temperature resistant high-speed camera, 6-Electrical impedance monitoring module, 61-Ring electrode, 62-Electrical impedance analyzer, 7-Data processing and control module. Detailed Implementation

[0046] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings and reference numerals, so that those skilled in the art can implement them after reading this specification. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0047] The first aspect of this application discloses as follows: Figure 1 The method for controlling the quality of heated mixing of recycled asphalt mixtures, as shown, includes the following steps:

[0048] S1. Pretreatment of waste asphalt:

[0049] After the recycled RAP is fully crushed, it is mixed with SBS modifier and heated and stirred to make the SBS modifier uniformly dispersed in the RAP, thus obtaining pretreated RAP. The fluorescence properties of the styrene segments in the SBS modifier enable the pretreated RAP to emit blue-green fluorescence under ultraviolet excitation light at a wavelength of 365nm.

[0050] S2, Graphene modification of new asphalt:

[0051] A graphene modifier is incorporated into new asphalt, and the graphene modifier is uniformly dispersed in the new asphalt and forms a conductive network through a heating and shear dispersion process, resulting in graphene-modified new asphalt. The high conductivity of graphene means that the electrical impedance characteristics of the graphene-modified new asphalt are directly related to its dispersion state.

[0052] S3. Heating and mixing operation:

[0053] The pretreated RAP and the graphene-modified new asphalt are heated and mixed to obtain RAM;

[0054] S4. Monitoring of mixing data:

[0055] The heating and mixing zone is divided into equal parts. m The side length is a A cube mesh, in which a The value is determined based on the monitoring accuracy requirements, and in specific implementation... a The value is 1 / 10 to 1 / 20 of the side length of the heating and mixing region; the fluorescence of the pretreated RAP is excited by an ultraviolet excitation source with a wavelength of 365 nm, and the fluorescence intensity signal is obtained using a high-temperature resistant high-speed camera and a bandpass filter, thereby obtaining... t Time of the first n The fluorescence intensity value of the preprocessed RAP within a cubic grid. F ( n , t The graphene-modified asphalt is subjected to an alternating voltage through an annular electrode installed on the inner wall of the mixing device, and the electrical impedance value is obtained through an electrical impedance analyzer, thereby obtaining... t Time of the first n The electrical impedance value of the graphene-modified new asphalt within a cubic grid. Z ( n , t );

[0056] S5. Establishment of an index for the degree of integration between new and old asphalt:

[0057] Based on fluorescence intensity value F ( n , t )calculate t Fluorescence distribution uniformity index at time U F As shown in the following formula:

[0058] (1)

[0059] in, s F The standard deviation of the fluorescence intensity value. m F This represents the average fluorescence intensity value; U F The value reflects the dispersion of fluorescence intensity data. As the degree of fusion between new and old asphalt increases, the spatial distribution of fluorescence intensity data tends to be more consistent. U F The larger the value, the more uniform the RAP distribution after preprocessing;

[0060] Based on electrical impedance value Z ( n , t )calculate t Uniformity index of impedance distribution at time t U Z As shown in the following formula:

[0061] (2)

[0062] in, s Z The standard deviation of the electrical impedance value. m Z This represents the average value of the electrical impedance. U Z Reflecting the dispersion of electrical impedance data, as the degree of fusion between new and old asphalt increases, the spatial distribution of electrical impedance data tends to be more consistent. U Z The larger the value, the more uniform the distribution of the new asphalt after graphene modification;

[0063] Indicators of the degree of integration between new and old asphalt K Satisfy the following expression:

[0064] (3)

[0065] in, α and β As s F and s Z The weight parameters change dynamically based on the value of the parameter, satisfying the following conditions: α + β =1, and α Satisfy the following expression:

[0066] (4)

[0067] In practice, the more uniform the distribution of RAP after preprocessing, the better. s F The value approaches 0. α and β The values ​​then approach 0 and 1 respectively, meaning that the uniformity of the distribution of the graphene-modified new asphalt becomes an indicator of the degree of fusion between the old and new asphalt. K The main influencing factors; the more uniform the distribution of the graphene-modified new asphalt, s Z The value approaches 0. α and β The values ​​then approach 1 and 0 respectively, meaning that the uniformity of the pretreated RAP distribution becomes an indicator of the degree of fusion between the old and new asphalt.K The main influencing factors; when s F and s Z When the values ​​of approach equality, α and β The values ​​then approached 0.5 and 0.5 respectively, indicating that the uniformity of distribution of the pretreated RAP and the graphene-modified new asphalt was related to the degree of fusion between the old and new asphalt. K The degree of influence is the same;

[0068] The threshold value for the degree of fusion between new and old asphalt that enables RAM performance to meet requirements was obtained through experiments. K min That is, when K ≥ K min The degree of fusion between new and old asphalt is determined to meet the requirements. In practice, the threshold value of the degree of fusion between new and old asphalt that ensures the RAM's resistance to rutting and cracking is obtained from the test results before construction. K min It is 0.85;

[0069] S6. Mixing process control:

[0070] when K < K min At that time, that is K When the value is less than 0.85, the degree of fusion between the new and old asphalt is deemed insufficient, and the remaining mixing time Δ of the mixing unit is triggered. T The control is shown in the following formula:

[0071] (5)

[0072] in, c The gain parameter is used to control the gain, and its value ranges from [0.5, 2]. c The value decreases as the heating and mixing process progresses; control gain parameter c It can solve the problems of insufficient adjustment in the early stage and excessive adjustment in the later stage caused by fixed gain.

[0073] The second aspect of this application discloses, as follows: Figure 2-3 The recycled asphalt mixture heating and mixing device shown is used to implement the recycled asphalt mixture heating and mixing quality control method, including mixing device platform 1, RAP pretreatment module 2, new asphalt modification module 3, main mixing module 4, fluorescence monitoring module 5, electrical impedance monitoring module 6, and data processing and control module 7.

[0074] The mixing plant platform 1 includes a material lifting device 11, a chute 12, a mixing plant support 13, a mobile batching trolley 14, and a mobile batching track 15. The mixing plant support is formed by assembling steel components to form a platform. The material lifting device 11 is located on both sides of the mixing plant support 13 and is used to transport RAP or new asphalt to a higher position, and then pour it into the mobile batching trolley 14 via the chute 12 located at the top of the material lifting device 11. The mobile batching trolley 14 is placed on the mobile batching track 15 and can move horizontally.

[0075] The RAP pretreatment module 2 includes a RAP feed hopper 21, an SBS modifier quantitative feeding device 22, and a first heating mixing tank 23. The RAP feed hopper 21 is located below the moving batching track 15 and above the first heating mixing tank 23, and is used to receive RAP from the moving batching trolley 14. The SBS modifier quantitative feeding device 22 is located above the first heating mixing tank 23, and is used to store and quantitatively feed SBS modifier into the first heating mixing tank 23. The first heating mixing tank 23 has built-in spiral stirring blades and an electric heating device, which makes the SBS modifier uniformly dispersed in the RAP through heating and mixing operations.

[0076] The new asphalt modification module 3 includes a graphene storage tank 31, a high-speed shear disperser 32, and a second heating mixing tank 33. The graphene storage tank 31 is located above the second heating mixing tank 33 and is used to store and quantitatively deliver graphene modifier into the second heating mixing tank 33. The second heating mixing tank 33 has built-in spiral stirring blades and an electric heating device. The high-speed shear disperser 32 generates strong shear force through high-speed rotation. The high-speed shear disperser 32 and the second heating mixing tank 33, through heating and shear dispersion processes, ensure that the graphene modifier is uniformly dispersed in the new asphalt.

[0077] The main mixing module 4 includes a feed hopper 41, a batching and weighing device 42, a preheating box 43, a mixing device 44, a third heating mixing tank 45, and a discharge port 46. The feed hopper 41 is located below the first heating mixing tank 23 and the second heating mixing tank 33, and is used to receive pretreated RAP or graphene-modified new asphalt. The batching and weighing device 42 is located below the feed hopper 41, and is used to weigh the pretreated RAP or the graphene-modified new asphalt and transport it to the preheating box 43. The preheating box 43 is located below the batching and weighing device 42, and is used to preheat the pretreated RAP and the graphene-modified new asphalt. The third heating mixing tank 45 is located below the preheating box 43 and above the discharge port 46, and is equipped with the mixing device 44 inside, used to mix the pretreated RAP and the graphene-modified new asphalt.

[0078] The fluorescence monitoring module 5 includes an ultraviolet excitation light source 51 and a high-temperature resistant high-speed camera 52, both of which are installed on the side wall of the third heating and mixing tank 45. The ultraviolet excitation light source 51 is an LED lamp capable of exciting ultraviolet light. The high-temperature resistant high-speed camera 52 is used to capture the fluorescence signal of RAP in real time and is equipped with a bandpass filter to ensure the accuracy of fluorescence signal acquisition. The center wavelength of the bandpass filter is 515nm to match the blue-green fluorescence peak of the SBS modifier.

[0079] The electrical impedance monitoring module 6 includes a ring electrode 61 and an electrical impedance analyzer 62, both installed on the side wall of the third heating mixing tank 45 and evenly distributed along the circumference; the electrical impedance monitoring module 6 and the fluorescence monitoring module 5 are alternately distributed to avoid mutual interference; the ring electrode 61 is used to apply an alternating voltage to the third heating mixing tank 45; the electrical impedance analyzer 62 is used to acquire the electrical impedance data of the graphene-modified new asphalt;

[0080] The data processing and control module 7 is integrated into an embedded computer and is used to receive and process the data acquired by the fluorescence monitoring module 5 and the electrical impedance monitoring module 6, as well as to control the working parameters of the mixing device 44 according to the degree of fusion of new and old asphalt.

[0081] Therefore, by utilizing the fluorescence properties of SBS modifiers and the electrical impedance properties of graphene modifiers, multi-physics field synergistic monitoring can be achieved through ultraviolet excitation and a ring electrode to obtain the fluorescence intensity of waste asphalt mixtures and the electrical impedance data of new asphalt. This allows for the simultaneous, independent, and non-contact acquisition of the dispersion uniformity of new and old asphalt during heating and mixing, overcoming the lag of traditional methods such as visual inspection and sampling, and overcoming the limitation of single methods in simultaneously assessing the dispersion status of new and old asphalt, thus preventing the quantification of the interfacial fusion degree. Both SBS and graphene modifiers are asphalt modifiers that can effectively improve the various physical and mechanical properties of RAM (asphalt-based asphalt mixtures), and their application in the dispersion process of new and old asphalt... In the monitoring of the degree of integration, the performance of RAM products is improved while realizing the sensing function; the fluorescence distribution uniformity index and the electrical impedance distribution uniformity index are calculated based on real-time monitoring data, and then a quantitative index of the degree of integration between new and old asphalt is established, which directly reflects the degree of micro-integration between new and old asphalt and forms a scientific evaluation system; the remaining mixing time is automatically adjusted in real time according to the degree of integration index between new and old asphalt to avoid insufficient integration or overheating caused by fixed parameters, and to realize dynamic adaptive control of the heating and mixing operation; through modular device design, automated production, heating and mixing operation monitoring and adaptive control are realized, meeting the needs of recycled asphalt mixture heating and mixing operation for high efficiency, intelligence and precision.

[0082] The above describes one or more embodiments of the present invention in a relatively specific and detailed manner, but it should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for quality control of heated mixing of recycled asphalt mixtures, characterized in that, Includes the following steps: S1. Pretreatment of waste asphalt: The recycled waste asphalt pavement material RAP is fully crushed, mixed with SBS modifier and heated and stirred to make the SBS modifier uniformly dispersed in the RAP, thus obtaining pretreated RAP; the fluorescence properties of SBS modifier enable the pretreated RAP to emit blue-green fluorescence under ultraviolet excitation light. S2. Graphene modification of new asphalt: Graphene modifier is added to new asphalt, and the graphene modifier is uniformly dispersed in the new asphalt through heating and shear dispersion processes to obtain graphene-modified new asphalt. S3. Heating and mixing operation: The pretreated RAP and the graphene-modified new asphalt are heated and mixed to obtain recycled asphalt mixture RAM. S4. Monitoring of mixing data: The heated mixing area is divided into multiple cubic grids of the same size; the fluorescence of the pretreated RAP is excited by an ultraviolet excitation light source, and the fluorescence intensity signal is acquired using a high-temperature resistant high-speed camera and a bandpass filter, thereby obtaining... t Time of the first n The fluorescence intensity value of the preprocessed RAP within a cubic grid. F ( n , t The graphene-modified asphalt is subjected to an alternating voltage through an annular electrode installed on the inner wall of the mixing device, and the electrical impedance value is obtained through an electrical impedance analyzer, thereby obtaining... t Time of the first n The electrical impedance value of the graphene-modified new asphalt within a cubic grid. Z ( n , t ); S5. Establishment of the index for the degree of fusion between new and old asphalt: based on fluorescence intensity values. F ( n , t )calculate t Fluorescence distribution uniformity index at time U F As shown in the following formula: in, σ F The standard deviation of the fluorescence intensity value. μ F This represents the average fluorescence intensity value; Based on electrical impedance value Z ( n , t )calculate t Uniformity index of impedance distribution at time t U Z As shown in the following formula: in, σ Z The standard deviation of the electrical impedance value. μ Z This represents the average value of the electrical impedance. Indicators of the degree of integration between new and old asphalt K Satisfy the following expression: in, α and β As σ F and σ Z The weight parameters change dynamically based on the value of the parameter, satisfying the following conditions: α + β =1, and α Satisfy the following expression: The threshold value for the degree of fusion between old and new asphalt that enables RAM performance to meet requirements was obtained through experiments. K min That is, when K ≥ K min The degree of fusion between the old and new asphalt is determined to meet the requirements. S6. Mixing process control: When K < K min If the degree of fusion between the old and new asphalt is determined to be insufficient, the remaining mixing time Δ of the mixing unit will be reduced. T The control is shown in the following formula: in, γ The gain parameter is used to control the gain, and its value ranges from [0.5, 2]. γ The value decreases as the heating and mixing process progresses.

2. A heating and mixing device for recycled asphalt mixtures, characterized in that, The method for controlling the quality of heated mixing of recycled asphalt mixture as described in claim 1 includes a mixing device platform, a RAP pretreatment module, a new asphalt modification module, a main mixing module, a fluorescence monitoring module, an electrical impedance monitoring module, and a data processing and control module. The mixing plant platform includes a material lifting device, a chute, a mixing plant support frame, a mobile batching trolley, and a mobile batching track. The mixing plant support frame is constructed from steel components to form the platform. The material lifting device is located on both sides of the mixing plant support frame and is used to transport RAP or new asphalt to a higher position, and then pour it into the mobile batching trolley via the chute located at the top of the material lifting device. The mobile batching trolley is placed on the mobile batching track and can move horizontally. The RAP pretreatment module includes a RAP feed hopper, an SBS modifier quantitative dispensing device, and a first heating and mixing tank. The RAP feed hopper is located below the moving batching track and above the first heating and mixing tank, and is used to receive RAP from the moving batching trolley. The SBS modifier quantitative dispensing device is located above the first heating and mixing tank, and is used to store and quantitatively dispense SBS modifier into the first heating and mixing tank. The first heating and mixing tank has built-in spiral stirring blades and an electric heating device, which, through heating and mixing operations, ensures that the SBS modifier is uniformly dispersed in the RAP. The new asphalt modification module includes a graphene storage tank, a high-speed shear disperser, and a second heated mixing tank. The graphene storage tank is located above the second heated mixing tank and is used to store and quantitatively deliver graphene modifiers into the second heated mixing tank. The second heated mixing tank has built-in spiral stirring blades and an electric heating device. The high-speed shear disperser generates strong shear force through high-speed rotation. The high-speed shear disperser and the second heated mixing tank, through heating and shear dispersion processes, ensure that the graphene modifiers are uniformly dispersed in the new asphalt. The main mixing module includes a feed hopper, a batching and weighing device, a preheating box, a mixing device, a third heated mixing tank, and a discharge port. The feed hopper is located below the first and second heated mixing tanks and is used to receive pretreated RAP or graphene-modified new asphalt. The batching and weighing device is located below the feed hopper and is used to weigh the pretreated RAP or graphene-modified new asphalt and transport it to the preheating box. The preheating box is located below the batching and weighing device and is used to preheat the pretreated RAP and the graphene-modified new asphalt. The third heated mixing tank is located below the preheating box and above the discharge port, and is equipped with the mixing device inside for mixing the pretreated RAP and the graphene-modified new asphalt. The fluorescence monitoring module includes an ultraviolet excitation light source and a high-temperature resistant high-speed camera, both of which are installed on the side wall of the third heating mixing tank; the ultraviolet excitation light source uses an LED lamp capable of exciting ultraviolet light; the high-temperature resistant high-speed camera is used to capture the fluorescence signal of RAP in real time and is equipped with a bandpass filter to ensure the accuracy of fluorescence signal acquisition. The electrical impedance monitoring module includes a ring electrode and an electrical impedance analyzer, both installed on the side wall of the third heating mixing tank and evenly distributed along the circumference; the electrical impedance monitoring module and the fluorescence monitoring module are alternately distributed to avoid mutual interference; the ring electrode is used to apply an alternating voltage to the third heating mixing tank; the electrical impedance analyzer is used to acquire the electrical impedance data of the graphene-modified new asphalt; The data processing and control module is integrated into an embedded computer. It is used to receive and process the data acquired by the fluorescence monitoring module and the electrical impedance monitoring module, and to control the working parameters of the mixing device according to the degree of fusion between new and old asphalt.

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