Dual-mode self-adjusting switching type chemical modified asphalt preparation device and evaluation method thereof

Abstract

The invention discloses a dual-mode self-adjusting switching type chemical modified asphalt preparation device and an evaluation method thereof. At present, the quality of chemical modified asphalt is difficult to unify due to non-vacuum interference, and a unified and accurate evaluation mode is lacked. A main processing piece and a self-driving material adding piece are arranged in a sealed box body, and the sealed box body is connected with a vacuum suction system and a monitoring system; according to the chemical modified asphalt performance evaluation method, the chemical modified asphalt performance of the petroleum asphalt is evaluated according to the specific value of the performance difference rate D, and when the performance difference rate D is smaller than or equal to 10%, it is indicated that the chemical modified asphalt prepared from the petroleum asphalt is excellent in performance stability; when the performance difference rate is 10% lt; dlt; when the content is 20%, the chemical modified asphalt prepared from the petroleum asphalt is good in performance stability; when the performance difference rate D is greater than or equal to 20%, the chemical modified asphalt prepared from the petroleum asphalt is poor in performance stability.

Description

Technical Field

[0001] The present invention specifically relates to a dual-mode self-adjusting switching chemically modified asphalt preparation device and an evaluation method thereof. Background Art

[0002] Asphalt, as the basic material of asphalt pavement, plays a vital role in bonding aggregates in asphalt mixtures. With the increase in the number of vehicles and the frequent occurrence of extreme climate events, more stringent requirements are put forward for asphalt pavements. In order to extend the service life of the pavement, modified asphalt has been widely used. At present, modified asphalt is mainly polymer-modified asphalt, which is mostly achieved by adding polymer modifiers such as styrene-butadiene-styrene to asphalt and mechanically blending to achieve physical modification of traditional road petroleum asphalt. However, the current polymer modifiers are mainly in solid form, usually only miscible with the asphalt matrix at the material level, without obvious chemical reaction. In addition, the polymer modifiers and asphalt have large differences in properties such as molecular weight, density and structure, which makes it difficult to form a stable thermodynamic system after the modifier and asphalt are blended. In actual application, polymer-modified asphalt has problems such as high preparation temperature, high production energy consumption, complex preparation process and serious atmospheric pollutant emissions, which makes it difficult to ensure the full play of the modification effect, and has a significant negative impact on the performance of asphalt materials and the quality of road engineering construction.

[0003] In order to improve the environmental protection and durability of modified asphalt, chemical materials such as polyurethane, isocyanate, and polyphosphoric acid have been applied to the preparation of modified asphalt. The purpose is to achieve active modification of asphalt materials by chemically cross-linking reactions with asphalt molecules, fundamentally improve the performance of asphalt materials, show good performance, and be promoted and applied, but there are limitations in the asphalt preparation process. First, the asphalt preparation devices in asphalt laboratories and factories at home and abroad are all non-sealed, resulting in chemical modifiers such as polyurethane being in contact with air during the addition to unmodified asphalt and the mixing process. Taking isocyanate as an example, its effective active ingredient isocyanate (–NCO) group can react with moisture in the air to generate substituted urea and other substances, which in turn affects the chemically modified product. Second, the performance of chemically modified asphalt is closely related to the reaction process of modifier-asphalt. When preparing modified asphalt, it is necessary to ensure that the modifier and asphalt react fully. When different amounts or different types of chemical modifiers are added to unmodified asphalt, the required reaction time will also be different. At present, empirical methods are mostly used to determine the reaction process of chemical modifiers and unmodified asphalt. It is impossible to make real-time quantitative judgment of the modifier process, and the performance of the prepared modified asphalt is often insufficient. Summary of the invention

[0004] The present invention provides a dual-mode self-adjusting and switching chemical modified asphalt preparation device and its evaluation method to solve the above problems.

[0005] A dual-mode self-adjusting and switching chemical modified asphalt preparation device includes a sealed box body, a main processing component, a self-driven feeding component, a vacuum suction system, and a monitoring system. The main processing component and the self-driven feeding component are arranged in the sealed box body, and the sealed box body is respectively connected to the vacuum suction system and the monitoring system;

[0006] The main processing component includes a support and limit frame, a self-driven stirring component, and a bottom container. The support and limit frame is arranged in the sealed box body, the bottom container is vertically arranged at the bottom of the support and limit frame, the top of the bottom container is an open container, and the self-driven stirring component is arranged at the top of the support and limit frame. The bottom of the self-driven stirring component passes through the bottom container;

[0007] The self-driven feeding component is arranged on the support and limit frame. The self-driven feeding component includes a push rod and a self-rotating container. The self-rotating container is arranged close to the top of the bottom container. The self-rotating container is hinged on the support and limit frame. A pouring notch is processed on one side of the self-rotating container close to the bottom container. The self-rotating container is provided with a push rod in cooperation. One end of the push rod is arranged on the support and limit frame, and the other end of the push rod is a close-fitting telescopic end that cooperates with the self-rotating container. When the push rod is in the retracted state, the self-rotating container is in the state of not pouring liquid; when the push rod is in the extended state to push the self-rotating container to rotate, the self-rotating container is in the state of pouring liquid.

[0008] As a preferred solution: The self-rotating container is provided with a guiding support frame. The guiding support frame is a convex-concave C-shaped frame body. The convex-concave C-shaped frame body includes a supporting rod, two first support columns, two second support columns, and two cross bars. The two cross bars are horizontally arranged in parallel on one side of the main processing component. A pouring gap for cooperating with the self-rotating container is formed between the ends of the two cross bars facing the main processing component. The outer wall of the self-rotating container is respectively hinged to the two cross bars. The two first support columns are vertically arranged in parallel below the pouring gap. Each first support column is fixedly connected to one end of the cross bar close to it. The two second support columns are vertically arranged in parallel at the other ends of the two cross bars. The upper end of each second support column is fixedly connected to the other end of the cross bar close to it. A supporting rod is arranged between the lower ends of the two second support columns. An access notch for cooperating with the push rod is formed by enclosing between the inner walls of the two second support columns and the top side of the supporting rod.

[0009] As a preferred solution: One rotating shaft is correspondingly arranged on each cross bar. The two rotating shafts are both arranged close to the main processing component. One end of each rotating shaft is hinged to its corresponding cross bar, and the other end of each rotating shaft is fixedly connected to the outer wall of the self-rotating container.

[0010] As a preferred solution: A recessed portion is processed on the outer wall of the self-rotating container on the side facing the push rod.

[0011] As a preferred solution: The push rod includes a hydraulic rod and a push wheel. One end of the hydraulic rod is horizontally fixed on the support and limit frame, and the other end of the hydraulic rod is a movable end. A push wheel is arranged on the movable end of the hydraulic rod, and the push wheel is arranged in cooperation with the concave part. When the push wheel is in use, the push wheel is abutted against the concave part under the push of the hydraulic rod.

[0012] As a preferred solution: An attenuated total reflection crystal layer is arranged inside the bottom container. The attenuated total reflection crystal layer is arranged at the bottom of the bottom container. The bottom container is provided with a heating device in cooperation. The heating device is arranged in the sealed box body. A spectral signal receiving device and an infrared spectrometer are arranged at the bottom of the bottom container. The bottom of the bottom container is connected to the infrared spectrometer through the spectral signal receiving device.

[0013] As a preferred solution: The vacuum pumping system includes a vacuum pump. An exhaust valve and a suction valve are respectively arranged on the sealed box body. The vacuum pump is connected to the inside of the sealed box body through the sealed box body.

[0014] As a preferred solution: The self-driven stirring member includes a top-mounted motor, a stirring rod and a stirring head. The top-mounted motor is fixedly connected to the support and limit frame. The power output shaft of the top-mounted motor is connected to one end of the stirring rod, and the other end of the stirring rod is provided with a stirring head.

[0015] As a preferred solution: The monitoring system includes a total controller, a temperature control member, a pressure control member and a computer. The temperature control member and the pressure control member are arranged on the sealed box body. The temperature detection ends of the temperature control member and the pressure control member are respectively arranged inside the sealed box body. The total controller is electrically connected to the self-driven stirring member, the exhaust valve, the suction valve, the vacuum pump, the temperature control member, the pressure control member and the push rod respectively. The computer is connected to the total controller.

[0016] A dual-mode self-adjusting switching chemical modified asphalt evaluation method is realized by using the above-mentioned dual-mode self-adjusting switching chemical modified asphalt preparation device. The chemical modified asphalt performance evaluation method includes the following steps:

[0017] Step 1: Select and determine the type of unmodified petroleum asphalt according to the evaluation requirements, and test and obtain the basic performance indexes of the unmodified petroleum asphalt;

[0018] Step 2: Process of obtaining modified data under vacuum environment conditions: Weigh a corresponding type of unmodified petroleum asphalt sample according to a predetermined amount and place it in a bottom container. Start the heating device and the temperature control component in the monitoring system to ensure that the unmodified petroleum asphalt sample is heated to a predetermined temperature and then stop heating and maintain a constant temperature state at the predetermined temperature. While controlling the exhaust valve to close through the total controller in the monitoring system, open the air extraction valve and the vacuum pump. The air extraction valve and the vacuum pump cooperate to ensure that the sealed box is in a vacuum state meeting the predetermined requirements. First, start the self-driven feeding component to pour the chemical modifier into the bottom container to form a mixture, then start the self-driven stirring component to stir at a predetermined stirring rate to form a chemically modified asphalt mixture. Finally, start the spectral signal receiving device and the infrared spectrometer to collect the infrared spectral information of the chemically modified asphalt mixture in the bottom container, and use computer processing software to monitor the consumption state of the active chemical functional groups of the modifier in the chemically modified asphalt mixture in real time until the active functional groups of the modifier are consumed or the content of the active functional groups no longer changes, then stop stirring to obtain the required chemically modified asphalt sample. In the chemically modified asphalt sample, obtain the measured value I of the performance index of the chemically modified asphalt under the vacuum environment. 真空 As the standard value;

[0019] Step 3: Process of obtaining modified data under air environment conditions: Open the sealed box to ensure that the air extraction valve and the vacuum pump are in a closed state, repeat the operation process of Step 2, obtain the consumption state of the active chemical functional groups of the modifier in the chemically modified asphalt mixture under the air environment conditions until the active functional groups of the modifier are consumed or the content of the active functional groups no longer changes, then stop stirring to obtain the required chemically modified asphalt sample. In the chemically modified asphalt sample, obtain the measured value I of the performance index of the chemically modified asphalt under the air environment conditions. 空气 , and calculate the difference rate of the performance indexes of the chemically modified asphalt under the vacuum environment conditions and the air environment conditions according to the formula. The calculation process is as follows:

[0020]

[0021] In the above formula, D is the performance difference rate; I 空气 is the measured value of the performance index of the chemically modified asphalt prepared under the air environment; I 真空 is the measured value of the performance index of the chemically modified asphalt prepared under the vacuum environment; I 空气 and I 真空It is the same performance index under different asphalt preparation conditions. According to the specific value of the performance difference rate D, the performance stability of the chemically modified asphalt against environmental factor interference is evaluated. When the performance difference rate D ≤ 10%, it indicates that the performance stability of the chemically modified asphalt prepared with this type of petroleum asphalt is excellent; when the performance difference rate is 10% < D < 20%, it indicates that the performance stability of the chemically modified asphalt prepared with this type of petroleum asphalt is good; when the performance difference rate D ≥ 20%, it indicates that the performance stability of the chemically modified asphalt prepared with this type of petroleum asphalt is poor.

[0022] Compared with the prior art, the present invention provides a dual-mode self-adjusting and switching chemically modified asphalt preparation device and its evaluation method, which have the following beneficial effects:

[0023] 1. The dual-mode self-adjusting and switching chemically modified asphalt preparation device in the present invention forms a modular assembly structure through the mutual cooperation among the sealed box body, the main processing part, the self-driven feeding part, the vacuum suction system and the monitoring system, and can realize the switching test process under vacuum or air environment, and can accurately and independently control the conditions of stirring time, feeding rate and stirring rate involved in the feeding and stirring processes, which is beneficial to forming standard and accurate modified asphalt preparation process parameters and improving the flexibility of modified asphalt preparation.

[0024] 2. The present invention collects the infrared spectrum information of the asphalt sample during the preparation of the chemically modified asphalt online, realizes the real-time monitoring of the consumption state of the active chemical functional groups of the modifier, and stops stirring until the active functional groups of the modifier are consumed completely or the content of the active functional groups no longer changes.

[0025] 3. The dual-mode self-adjusting and switching chemically modified asphalt preparation device in the present invention can not only realize the vacuum treatment of the original materials such as asphalt and chemical modifiers, but also ensure the addition of chemical modifiers to unmodified asphalt and the setting of a full-process vacuum environment during the mixing process. During the mixing process, there is no need to open the sealed box body, which improves the control accuracy of the preparation conditions.

[0026] 4. The dual-mode self-adjusting and switching chemically modified asphalt preparation device in the present invention can realize the preparation of chemically modified asphalt in a vacuum environment and an air environment. By constructing an index system under the dual preparation environments, the performance of the chemically modified asphalt is comprehensively evaluated and analyzed. The dual-mode self-adjusting and switching chemically modified asphalt preparation method in the present invention also provides a unified and standardized evaluation method for the data result analysis in experiments and engineering applications, which is beneficial to standardizing the operation process of test environment switching and improving the accuracy of data acquisition. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a three-dimensional structural schematic diagram of the dual-mode self-adjusting and switching chemically modified asphalt preparation device in the present invention;

[0028] Figure 2 Schematic three-dimensional structure diagram of the connection relationship between the main processing component and the self-driven feeding component;

[0029] Figure 3 First front view structure diagram of the connection relationship between the main processing component and the self-driven feeding component, in which the rotating container is in the state of non-tipping feeding;

[0030] Figure 4 First front view structure diagram of the connection relationship between the main processing component and the self-driven feeding component, in which the rotating container is in the state of tipping feeding;

[0031] Figure 5 Top view structure diagram of the connection relationship between the main processing component and the self-driven feeding component;

[0032] Figure 6 Schematic three-dimensional structure diagram of the convex-concave C-shaped frame;

[0033] Figure 7 Electric control flow chart of the monitoring system.

[0034] In the figure: 1 - sealed box body; 2 - main processing component; 2-1 - support and limit frame; 2-2 - self-driven stirring component; 2-2-1 - top-mounted motor; 2-2-2 - stirring rod; 2-2-3 - stirring head; 2-3 - bottom-mounted container; 3 - self-driven feeding component; 3-1 - push rod; 3-1-1 - hydraulic rod; 3-1-2 - push wheel; 3-2 - rotating container; 3-2-1 - tipping notch; 3-3 - support rod; 3-4 - first support column; 3-5 - second support column; 3-6 - cross bar; 3-7 - tipping gap; 3-8 - inlet and outlet notch; 4 - rotating shaft; 5 - recessed part; 7 - heating device; 8-1 - total controller; 8-2 - temperature control component; 8-3 - air pressure control component; 9 - spectral signal receiving device; 10 - infrared spectrometer; 11 - vacuum pump. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] Specific embodiment one: In combination with Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7To describe this embodiment, the dual-mode self-adjusting and switching chemical modified asphalt preparation device in this embodiment includes a sealed box body 1, a main processing part 2, a self-driven feeding part 3, a vacuum pumping system and a monitoring system. The main processing part 2 and the self-driven feeding part 3 are arranged in the sealed box body 1, and the sealed box body 1 is respectively connected to the vacuum pumping system and the monitoring system. The sealed box body 1 is a square box body, which is an environmental box body. When it is in a vacuum state, all parts are in a sealed state, providing favorable sealing conditions for the vacuum environment.

[0037] The main processing part 2 includes a support and limit frame 2-1, a self-driven stirring part 2-2 and a bottom container 2-3. The support and limit frame 2-1 is arranged in the sealed box body 1, the bottom container 2-3 is vertically arranged at the bottom of the support and limit frame 2-1, the bottom container 2-3 is a container with an open top, and the self-driven stirring part 2-2 is arranged at the top of the support and limit frame 2-1. The bottom of the self-driven stirring part 2-2 passes through the bottom container 2-3.

[0038] The self-driven feeding part 3 is arranged on the support and limit frame 2-1. The self-driven feeding part 3 includes a push rod 3-1 and a self-rotating container 3-2. The self-rotating container 3-2 is arranged near the top of the bottom container 2-3. The self-rotating container 3-2 is hinged on the support and limit frame 2-1. A pouring notch 3-2-1 is processed on one side of the self-rotating container 3-2 close to the bottom container 2-3. The self-rotating container 3-2 is cooperatively provided with a push rod 3-1. One end of the push rod 3-1 is arranged on the support and limit frame 2-1, and the other end of the push rod 3-1 is a fitting telescopic end that cooperates with the self-rotating container 3-2. When the push rod 3-1 is in a retracted state, the self-rotating container 3-2 is in a state of not pouring liquid; when the push rod 3-1 is in an extended state to push the self-rotating container 3-2 to rotate, the self-rotating container 3-2 is in a state of pouring liquid.

[0039] Embodiment 2: This embodiment is a further limitation of Embodiment 1. In this embodiment, the self-rotating container 3-2 is cooperatively provided with a guiding support frame. The guiding support frame is a convex-concave C-shaped frame body, which includes a supporting rod 3-3, two first support columns 3-4, two second support columns 3-5, and two cross bars 3-6. The two cross bars 3-6 are horizontally arranged in parallel on one side of the main processing part 2. A dumping gap 3-7 for cooperating with the self-rotating container 3-2 is formed between the ends of the two cross bars 3-6 facing the main processing part 2. The outer wall of the self-rotating container 3-2 is respectively hinged to the two cross bars 3-6. The two first support columns 3-4 are vertically arranged in parallel below the dumping gap 3-7. Each first support column 3-4 is fixedly connected to one end of the cross bar 3-6 close to it. The two second support columns 3-5 are vertically arranged in parallel at the other ends of the two cross bars 3-6. The upper end of each second support column 3-5 is fixedly connected to the other end of the cross bar 3-6 close to it. A supporting rod 3-3 is arranged between the lower ends of the two second support columns 3-5. An access notch 3-8 for cooperating with the push rod 3-1 is formed by enclosing between the inner walls of the two second support columns 3-5 and the top side of the supporting rod 3-3.

[0040] Embodiment 3: This embodiment is a further limitation of Embodiment 1 or 2. In this embodiment, a rotating shaft 4 is correspondingly arranged on each cross bar 3-6. The two rotating shafts 4 are both arranged close to the main processing part 2. One end of each rotating shaft 4 is hinged to its corresponding cross bar 3-6, and the other end of each rotating shaft 4 is fixedly connected to the outer wall of the self-rotating container 3-2.

[0041] Embodiment 4: This embodiment is a further limitation of Embodiment 1, 2 or 3. A recessed part 5 is machined on the outer wall of the self-rotating container 3-2 facing the push rod 3-1. The recessed part 5 is specifically a groove or a pit, which is used to provide a stable supporting position for the push rod 3-1.

[0042] Embodiment 5: This embodiment is a further limitation of Embodiment 1, 2, 3 or 4. In this embodiment, the push rod 3-1 includes a hydraulic rod 3-1-1 and a push wheel 3-1-2. One end of the hydraulic rod 3-1-1 is horizontally fixed on the support and limit frame 2-1. The other end of the hydraulic rod 3-1-1 is a mobile end. A push wheel 3-1-2 is arranged on the mobile end of the hydraulic rod 3-1-1. The push wheel 3-1-2 is arranged in cooperation with the recessed part 5. When the push wheel 3-1-2 is in use, the push wheel 3-1-2 is abutted against the recessed part 5 under the push of the hydraulic rod 3-1-1.

[0043] Embodiment Six: This embodiment is a further limitation of Embodiment One, Two, Three, Four, or Five. An attenuated total reflection crystal layer is provided inside the bottom-mounted container 2-3. The attenuated total reflection crystal layer is arranged at the bottom of the bottom-mounted container 2-3. The bottom-mounted container 2-3 is cooperatively provided with a heating device 7. The heating device 7 is arranged inside the sealed box 1. A spectral signal receiving device 9 and an infrared spectrometer 10 are provided at the bottom of the bottom-mounted container 2-3. The bottom of the bottom-mounted container 2-3 is connected to the infrared spectrometer 10 through the spectral signal receiving device 9. The spectral signal receiving device 9 is an existing spectral signal receiving device, and its working principle is the same as that of the existing spectral signal receiving device. The infrared spectrometer 10 is an existing infrared spectrometer, and its working principle is the same as that of the existing infrared spectrometer.

[0044] Embodiment Seven: This embodiment is a further limitation of Embodiment One, Two, Three, Four, Five, or Six. In this embodiment, the vacuum suction system includes a vacuum pump 11. An exhaust valve and a suction valve are respectively arranged on the sealed box 1. The vacuum pump 11 is connected to the inside of the sealed box 1 through the sealed box 1. The vacuum pump 11 is a vacuum air pump. The vacuum pump 11 is an existing pump body product, and its working principle is the same as that of the existing vacuum pump.

[0045] Embodiment Eight: This embodiment is a further limitation of Embodiment One, Two, Three, Four, Five, Six, or Seven. In this embodiment, the self-driven stirring member 2-2 includes a top-mounted motor 2-2-1, a stirring rod 2-2-2, and a stirring head 2-2-3. The top-mounted motor 2-2-1 is fixedly connected to the support and limit frame 2-1. The power output shaft of the top-mounted motor 2-2-1 is connected to one end of the stirring rod 2-2-2. The other end of the stirring rod 2-2-2 is provided with a stirring head 2-2-3. The stirring head 2-2-3 is an existing structure for realizing stirring, specifically a stirring blade or a mixing blade, which plays a role in stirring the mixture.

[0046] Embodiment Nine: This embodiment is a further limitation of Embodiment One, Two, Three, Four, Five, Six, Seven, or Eight. The monitoring system includes a total controller 8-1, a temperature control member 8-2, a pressure control member 8-3, and a computer. The temperature control member 8-2 and the pressure control member 8-3 are arranged on the sealed box 1. The temperature detection ends of the temperature control member 8-2 and the pressure control member 8-3 are respectively arranged inside the sealed box 1. The total controller 8-1 is electrically connected to the self-driven stirring member 2-2, the exhaust valve, the suction valve, the vacuum pump 11, the temperature control member 8-2, the pressure control member 8-3, and the push rod 3-1 respectively. The computer is connected to the total controller 8-1.

[0047] The dual-mode self-adjusting switching chemical modified asphalt preparation device in the present invention is a device for preparing chemical modified asphalt in a vacuum environment. The self-driven feeding part 3 and the self-driven stirring part 2-2 are located in the support and limit frame 2-1, jointly constituting the processing device. The spectral signal receiving device 9 and the infrared spectrometer 10 cooperate to complete the real-time monitoring of the chemical modified asphalt preparation process, ensuring that the mixture reacts sufficiently. The sealed box 1 is connected to the vacuum pump through a pipeline. Combining the control unit and the power supply unit, the vacuum pumping process of the environmental box and the independent control of the motor and the feeding device are realized. The present invention can ensure the switching between the vacuum environment and the air environment under the same basic preparation structure.

[0048] Specific Embodiment Ten: Combining Figures 1 to 7 To illustrate this embodiment, the method for evaluating the performance of chemical modified asphalt in this embodiment is to prepare chemical modified asphalt specimens in a vacuum environment and an air environment respectively, and test to obtain the standard values of the road performance of the asphalt specimens under vacuum conditions and the measured values under the air environment. By constructing a dual-preparation environment index system, the influence of environmental factors on the performance of chemical modified asphalt is determined. The specific process includes the following steps:

[0049] Step 1: Select and determine the type of unmodified petroleum asphalt according to the evaluation requirements, and test to obtain the basic performance indexes of the unmodified petroleum asphalt.

[0050] Step 2: Process for obtaining modification data under vacuum environment conditions: Weigh the selected unmodified petroleum asphalt sample of the corresponding type according to a predetermined amount and put it into the bottom container 2-3. Start the heating device 7 and the temperature control part 8-2 in the monitoring system to ensure that the unmodified petroleum asphalt sample is heated to a predetermined temperature and then stop heating and maintain a constant temperature state at the predetermined temperature. While controlling the exhaust valve to close through the main controller 8-1 in the monitoring system, open the air extraction valve and the vacuum pump 11. The air extraction valve and the vacuum pump 11 cooperate to ensure that the sealed box 1 is in a vacuum state as required. First, start the self-driven feeding part 3 to pour the chemical modifier into the bottom container 2-3 to form a mixture, then start the self-driven stirring part 2-2 to stir at a predetermined stirring rate to form a chemical modified asphalt mixture. Finally, start the spectral signal receiving device 9 and the infrared spectrometer 10 to collect the infrared spectral information of the chemical modified asphalt mixture in the bottom container 2-3, and use computer processing software to monitor the consumption state of the active chemical functional groups of the modifier in the chemical modified asphalt mixture in real time until the active functional groups of the modifier are consumed or the content of the active functional groups no longer changes, then stop stirring to obtain the required chemical modified asphalt specimen. According to the method specified in the "Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering" (JTG E20–2011), use a dynamic shear rheometer to test and obtain the rutting factor of the chemical modified asphalt at 60°C under vacuum environment, and use a penetrometer to test and obtain the penetrability of the chemical modified asphalt at 25°C under vacuum environment. And respectively record the measured values I of the corresponding performance indexes of both真空 As the standard value. The calculation formula of the rutting factor is I 真空 = G* / sinδ, where G* represents the dynamic shear modulus of the asphalt specimen and δ represents the phase angle of the asphalt specimen; the penetration is based on the actual penetration depth when the standard needle of the penetrometer penetrates the specimen for 5 s under a load of 100 g. The penetrometer is an existing penetrometer, and its working principle is the same as that of the existing penetrometer.

[0051] Step 3: Process of obtaining modification data under air environmental conditions: Open the sealed box 1, ensure that the air extraction valve and the vacuum pump 11 are in the closed state, repeat the operation process of Step 2, obtain the consumption state of the active chemical functional groups of the modifier in the chemically modified asphalt mixture under air environmental conditions, and stop stirring until the active functional groups of the modifier are consumed or the content of the active functional groups no longer changes, and obtain the measured value I of the performance index of the chemically modified asphalt under air environmental conditions 空气 , and calculate the difference rate of the performance indexes of the chemically modified asphalt under vacuum environmental conditions and air environmental conditions according to the formula. The calculation process is as follows:

[0052]

[0053] In the above formula, D is the difference rate of performance; I 空气 is the measured value of the performance index of the chemically modified asphalt prepared under air environment; I 真空 is the measured value of the performance index of the chemically modified asphalt prepared under vacuum environment; I 空气 and I 真空 are the same performance indexes under different asphalt preparation conditions. Evaluate the performance stability of the chemically modified asphalt against environmental factor interference according to the specific value of the difference rate of performance D. When the difference rate of performance D ≤ 10%, it indicates that the performance stability of the chemically modified asphalt prepared with this type of petroleum asphalt is excellent; when the difference rate of performance is 10% < D < 20%, it indicates that the performance stability of the chemically modified asphalt prepared with this type of petroleum asphalt is good; when the difference rate of performance D ≥ 20%, it indicates that the performance stability of the chemically modified asphalt prepared with this type of petroleum asphalt is poor.

[0054] The specific structural details of the dual-mode self-adjusting and switching chemical modified asphalt preparation device in the present invention are as follows: In the present invention, the push rod 3-1 and the self-rotating container 3-2 cooperate to jointly form a material pusher. The self-rotating container 3-2 is hinged on the support and limit frame 2-1. The material pusher is electrically connected to the total controller 8-1. Specifically, it passes through the outer wall of the environmental chamber into the sealed box body 1 through the controller wire, and the perforation is sealed. Under the control of the total controller 8-1, the push rod 3-1 changes its telescopic length to achieve a 90-degree flipping attitude change of the self-rotating container 3-2, so that the chemical modifier in the self-rotating container 3-2 can be directed and poured into the bottom container 2-3, realizing the artificial independent control of the chemical modifier feeding process and the feeding rate.

[0055] In the present invention, an attenuated total reflection crystal window is embedded at the bottom of the bottom container 2-3, which can ensure the close contact between the asphalt sample and the ATR crystal. The bottom container 2-3 is connected to the spectral signal receiving device 9 by means of screw rotation, so that infrared light is reflected multiple times in the ATR crystal and the reflected light is transmitted to the infrared spectrometer 10. A signal transmission interface is provided outside the spectral signal receiving device 9, and it is connected to a computer through the signal transmission interface to realize the real-time update and display of the infrared spectral signal.

[0056] Combined Figures 1 to 7 Describe the specific test process of the present invention, specifically as follows:

[0057] I. Select A unmodified road petroleum asphalt produced by a petrochemical company in a certain province and B unmodified road petroleum asphalt produced by a petrochemical company in Shandong Province as the base asphalt respectively to prepare chemical modified asphalt. According to the "Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering" (JTG E20–2011), test their basic indexes, and the test results are shown in Table 1:

[0058] Table 1 Basic indexes of base asphalt

[0059]

[0060] Select the polyurethane prepolymer produced by a certain chemical group as the chemical modifier to prepare polyurethane prepolymer chemical modified asphalt. This polyurethane prepolymer chemical modifier is a colorless and transparent liquid. At 25 °C, its density is 1.08 g / cm 3 , and its viscosity is 2650 mPa·s.

[0061] II. Carry out the preparation of chemical modified asphalt on three dates with significantly different air humidities, measure and record the relative air humidity. Use the vacuum environment stirring device proposed in the present invention to prepare chemical modified asphalt under vacuum environment and air environment.

[0062] III. Insert the power cord, turn on the switch, connect to the computer, and prepare the reactive recycled asphalt. Pour 800 g of unmodified petroleum asphalt A into the stirring container, and pour 5% of the polyurethane prepolymer chemical modifier into the beaker according to the different mass fractions of the base asphalt. Close the door of the sealed box 1, adjust the temperature of the environmental chamber to 150 °C through the temperature control module, heat the asphalt to the melting temperature, and maintain a constant temperature of 150 °C. Close the exhaust valve, open the air extraction valve, start the vacuum air extraction pump, and the air in the environmental chamber is exhausted through the vacuum air extraction pipe until the reading of the air pressure gauge in the environmental chamber reaches -0.1 MPa. Pour all the chemical modifier into the stirring container through the feeding device, start the stirring device, and continuously stir the A base asphalt-polyurethane prepolymer chemical modification mixture in the stirring container at a speed of 2000 rpm.

[0063] Online collection of the infrared spectrum information of the mixture sample during the preparation of the chemically modified asphalt shows that at the initial mixing stage of the polyurethane prepolymer chemically modified asphalt, an obvious characteristic absorption band appears at the position of 2270 cm -1 in its infrared spectrum, which is caused by the stretching vibration of the excessive isocyanate functional group. The isocyanate functional group is the active reaction functional group of the polyurethane prepolymer. With the extension of the stirring time, the intensity of this characteristic peak decreases significantly, indicating that an effective reaction has occurred between the polyurethane prepolymer and the asphalt components, consuming the isocyanate functional group. Until after stirring for 180 min, the characteristic peak of the isocyanate functional group at the position of 2270 cm -1 no longer changes. Based on this, the reasonable stirring time can be determined to be 180 min. Therefore, stop stirring after continuously stirring for 180 min to obtain the sample of A polyurethane prepolymer chemically modified asphalt prepared in a vacuum environment.

[0064] IV. Take out the processing device from the environmental chamber and place it in an air environment. Connect the material pusher and the push rod control unit through a controller cable, and connect the push rod control unit and the push rod power supply unit through a power cable. Connect the stirrer motor and the stirrer control unit through a controller cable, and connect the stirrer control unit and the stirrer power supply unit through a power cable. Similar to the preparation in the vacuum environment, pour 800 g of the same unmodified petroleum asphalt A into the stirring container respectively. Similar to the preparation in the vacuum environment, pour 5% of the polyurethane prepolymer chemical modifier into a beaker. Similar to the preparation in the vacuum environment, use an external oil bath device to heat the asphalt to the melting temperature of 150 °C and maintain a constant temperature of 150 °C. Pour the polyurethane prepolymer chemical modifier into the stirring container through a feeding device, start the stirring device, and similar to the preparation in the vacuum environment, continuously stir the unmodified asphalt A - polyurethane prepolymer chemical modification mixture in the stirring container at a speed of 2000 rpm. Similar to the preparation in the vacuum environment, stop stirring until the specified stirring time of 180 min is reached to obtain the A polyurethane prepolymer chemically modified asphalt sample prepared in the air environment.

[0065] V. Repeat the above steps to prepare polyurethane prepolymer chemically modified asphalt using matrix asphalt B. Determine that the reasonable stirring time is also 180 min, and obtain the B polyurethane prepolymer chemically modified asphalt samples prepared in the vacuum environment and the air environment respectively.

[0066] VI. Change the stirring date and measure and record the air humidity. Repeat the above steps II and III to prepare A and B polyurethane prepolymer chemically modified asphalts under different air relative humidity conditions respectively. And under this air relative humidity, use the vacuum environment stirring device proposed by the present invention to prepare A and B polyurethane prepolymer chemically modified asphalts in the vacuum environment respectively. A total of 12 different polyurethane prepolymer chemically modified asphalt samples prepared on 3 different dates are obtained.

[0067] VII. Adopt the performance evaluation method proposed by the present invention, and according to the "Test Regulations for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20–2011), conduct 25 °C penetration and 60 °C rutting factor tests on the 12 chemically modified asphalts obtained in the vacuum environment and the air environment, calculate and obtain the vacuum - air environment performance difference rate, and evaluate the performance of the chemically modified asphalt, as shown in Table 2 below.

[0068] Table 2 Performance indicators of chemically modified asphalts obtained under different preparation conditions

[0069]

[0070] To further illustrate the rigor of the performance evaluation method of the chemically modified asphalt proposed in this patent, the differences in various indexes of the chemically modified asphalt obtained under different dates and preparation conditions, that is, the absolute values, were further cross-compared and tested. As shown in Table 3 and Table 4, specifically:

[0071] Table 3 Index differences of chemically modified asphalt prepared under different air humidities

[0072]

[0073] Table 4 Index differences of chemically modified asphalt prepared in a vacuum environment on different dates

[0074]

[0075] The following conclusions were found from the above test results:

[0076] Conclusion 1: The relative air humidities corresponding to three different stirring dates are 87%, 51% and 13% respectively. Comparing the performances of the polyurethane prepolymer chemically modified asphalt prepared under the above three different air environments, it can be found that the penetration degrees of both chemically modified asphalt A and B gradually increase with the decrease of air humidity. Among them, the increase amplitude of chemically modified asphalt A is obvious during the process of humidity from 87% to 13%, with a difference of 3 dmm; the increase amplitude of chemically modified asphalt B is obvious during the process of humidity from 87% to 13%, with a difference of 3.2 dmm. The rutting factor of chemically modified asphalt A decreases with the decrease of humidity, and the rutting factor of chemically modified asphalt B first increases and then decreases with the decrease of humidity. Among them, the decrease amplitude of chemically modified asphalt A is obvious during the process of humidity from 87% to 13%, with a difference of 1.3 kPa; the increase amplitude of chemically modified asphalt B is obvious during the process of humidity from 51% to 13%, with a difference of 1.2 kPa. From the difference rates of penetration degree and rutting factor in the vacuum-air environment in Table 2, it can be seen that the higher the air humidity, the greater the performance difference rate D between the vacuum and air environments. Among them, the highest value of the penetration degree difference rate D is 6.2%, which meets the specified allowable value of 10%; there are 4 groups where the rutting factor difference rate D exceeds 10%. Among them, the rutting factor difference rate value at an air humidity of 87% is the highest, reaching 22.6%, exceeding the specified allowable value of 20%; similar to the results of the index differences under different air humidities in Table 3, that is, the greater the difference in relative air humidity, the greater the difference in performance indexes. The above results show that the change of air humidity will have a significant impact on the performance of the polyurethane prepolymer chemically modified asphalt.

[0077] Conclusion 2: By comparing the properties of the vacuum environment chemically modified asphalt prepared by using the vacuum stirring device proposed in the present invention under the above three different air environments, it can be found that the index difference of the penetration degree is the lowest under stirring dates 1 and 3 (vacuum environment, B), which is 0.3 dmm, and it decreases by 2.1 dmm from the maximum value of the penetration degree index difference in Table 4 to the maximum value in Table 3; the index difference of the rutting factor is the lowest under stirring dates 1 and 3 (vacuum environment, A), which is 0.1 kPa, and it decreases by 0.7 kPa from the maximum value of the rutting factor index difference in Table 4 to the maximum value in Table 3. This shows that the properties of the polyurethane prepolymer chemically modified asphalt prepared under the vacuum environment are consistent, effectively excluding the influence of the external environment. Using the dual-mode self-adjusting switching type chemically modified asphalt preparation device in the present invention to prepare the chemically modified asphalt under the vacuum environment can provide a stable standard value for the determination of the properties of the chemically modified asphalt.

[0078] Conclusion 3: The properties of the chemically modified asphalt are significantly affected by the environment, resulting in a large difference in the stability results of different performance indicators. It is recommended that when preparing the chemically modified asphalt, the dual-mode self-adjusting switching type chemically modified asphalt preparation device and its evaluation method in the present invention be used, and multiple indicators be used to evaluate the performance stability of the chemically modified asphalt to ensure that the difference rate D is below 20%.

Claims

1. A dual-mode self-adjusting and switching chemical modified asphalt preparation device, characterized in that: It includes a sealed box body (1), a main processing part (2), a self-driven feeding part (3), a vacuum suction system and a monitoring system. The main processing part (2) and the self-driven feeding part (3) are arranged in the sealed box body (1), and the sealed box body (1) is respectively connected to the vacuum suction system and the monitoring system; The main processing part (2) includes a support and limit frame (2-1), a self-driven stirring part (2-2) and a bottom container (2-3). The support and limit frame (2-1) is arranged in the sealed box body (1), the bottom container (2-3) is vertically arranged at the bottom of the support and limit frame (2-1), the bottom container (2-3) is a container with an open top, and the self-driven stirring part (2-2) is arranged at the top of the support and limit frame (2-1). The bottom of the self-driven stirring part (2-2) penetrates into the bottom container (2-3); The self-driven feeding part (3) is arranged on the support and limit frame (2-1). The self-driven feeding part (3) includes a push rod (3-1) and a self-rotating container (3-2). The self-rotating container (3-2) is arranged close to the top of the bottom container (2-3). The self-rotating container (3-2) is hinged on the support and limit frame (2-1). A pouring notch (3-2-1) is processed on one side of the self-rotating container (3-2) close to the bottom container (2-3). The self-rotating container (3-2) is cooperatively provided with a push rod (3-1). One end of the push rod (3-1) is arranged on the support and limit frame (2-1), and the other end of the push rod (3-1) is a abutting and telescopic end that cooperates with the self-rotating container (3-2). When the push rod (3-1) is in the retracted state, the self-rotating container (3-2) is in the state of not pouring liquid; when the push rod (3-1) is in the extended state to push the self-rotating container (3-2) to rotate, the self-rotating container (3-2) is in the state of pouring liquid.

2. The dual-mode self-adjusting and switching type chemical modified asphalt preparation device according to claim 1, characterized in that: The self-rotating container (3-2) is cooperatively provided with a guiding support frame. The guiding support frame is a convex-concave U-shaped frame body. The convex-concave U-shaped frame body includes a support rod (3-3), two first support columns (3-4), two second support columns (3-5) and two cross bars (3-6). The two cross bars (3-6) are horizontally arranged in parallel on one side of the main processing part (2). A pouring gap (3-7) for cooperating with the self-rotating container (3-2) is formed between the ends of the two cross bars (3-6) facing the main processing part (2). The outer wall of the self-rotating container (3-2) is respectively hinged to the two cross bars (3-6). The two first support columns (3-4) are vertically arranged in parallel below the pouring gap (3-7). Each first support column (3-4) is fixedly connected to one end of the cross bar (3-6) close to it. The two second support columns (3-5) are vertically arranged in parallel at the other ends of the two cross bars (3-6). The upper end of each second support column (3-5) is fixedly connected to the other end of the cross bar (3-6) close to it. A support rod (3-3) is arranged between the lower ends of the two second support columns (3-5). An access notch (3-8) for cooperating with the push rod (3-1) is formed by enclosing between the inner walls of the two second support columns (3-5) and the top side of the support rod (3-3).

3. The dual-mode self-adjusting and switching chemical modified asphalt preparation device according to claim 1, wherein: A rotating shaft (4) is correspondingly arranged on each cross bar (3 - 6), and the two rotating shafts (4) are both arranged close to the main processing part (2). One end of each rotating shaft (4) is hinged on its corresponding cross bar (3 - 6), and the other end of each rotating shaft (4) is fixedly connected to the outer wall of the self - rotating container (3 - 2).

4. The dual-mode self-adjusting and switching chemical modified asphalt preparation device according to claim 3, wherein: A recessed part (5) is machined on the outer wall of the self - rotating container (3 - 2) facing the push rod (3 - 1).

5. The dual-mode self-adjusting and switching type chemical modified asphalt preparation device according to claim 4, wherein: The push rod (3 - 1) includes a hydraulic rod (3 - 1 - 1) and a push wheel (3 - 1 - 2). One end of the hydraulic rod (3 - 1 - 1) is horizontally fixed on the support and limit frame (2 - 1), the other end of the hydraulic rod (3 - 1 - 1) is a mobile end, and a push wheel (3 - 1 - 2) is arranged on the mobile end of the hydraulic rod (3 - 1 - 1). The push wheel (3 - 1 - 2) is arranged in cooperation with the recessed part (5). When the push wheel (3 - 1 - 2) is in use, the push wheel (3 - 1 - 2) abuts against the recessed part (5) under the push of the hydraulic rod (3 - 1 - 1).

6. The dual-mode self-adjusting and switching chemical modified asphalt preparation device according to claim 5, characterized in that: An attenuated total reflection crystal layer is arranged inside the bottom - placed container (2 - 3), and the attenuated total reflection crystal layer is arranged at the bottom of the bottom - placed container (2 - 3). The bottom - placed container (2 - 3) is provided with a heating device (7) in cooperation. The heating device (7) is arranged in the sealed box body (1). A spectral signal receiving device (9) and an infrared spectrometer (10) are arranged at the bottom of the bottom - placed container (2 - 3). The bottom of the bottom - placed container (2 - 3) is connected to the infrared spectrometer (10) through the spectral signal receiving device (9).

7. The dual-mode self-adjusting and switching type chemical modified asphalt preparation device according to claim 1 or 6, characterized in that: The vacuum pumping system includes a vacuum pump (11). An exhaust valve and a suction valve are respectively arranged on the sealed box body (1). The vacuum pump (11) is communicated with the inside of the sealed box body (1) through the sealed box body (1).

8. The dual-mode self-adjusting and switching type chemical modified asphalt preparation device according to claim 7, characterized in that: The self - driving stirring part (2 - 2) includes a top - mounted motor (2 - 2 - 1), a stirring rod (2 - 2 - 2) and a stirring head (2 - 2 - 3). The top - mounted motor (2 - 2 - 1) is fixedly connected to the support and limit frame (2 - 1). The power output shaft of the top - mounted motor (2 - 2 - 1) is connected to one end of the stirring rod (2 - 2 - 2), and the other end of the stirring rod (2 - 2 - 2) is provided with a stirring head (2 - 2 - 3).

9. The dual-mode self-adjusting and switching chemical modified asphalt preparation device according to claim 8, characterized in that: The monitoring system includes a total controller (8 - 1), a temperature control part (8 - 2), a pressure control part (8 - 3) and a computer. The temperature control part (8 - 2) and the pressure control part (8 - 3) are arranged on the sealed box body (1). The temperature - detecting ends of the temperature control part (8 - 2) and the pressure control part (8 - 3) are respectively arranged inside the sealed box body (1). The total controller (8 - 1) is electrically connected to the self - driving stirring part (2 - 2), the exhaust valve, the suction valve, the vacuum pump (11), the temperature control part (8 - 2), the pressure control part (8 - 3) and the push rod (3 - 1) respectively. The computer is connected to the total controller (8 - 1).

10. A dual-mode self-adjusting and switching type chemical modified asphalt evaluation method, which is realized by using the dual-mode self-adjusting and switching type chemical modified asphalt preparation device described in any one of claims 1 to 9, and is characterized in that: The dual - mode self - adjusting switching chemical modified asphalt evaluation method includes the following steps: Step 1: Select and determine the type of unmodified petroleum asphalt according to the evaluation requirements, and test to obtain the basic performance indexes of the unmodified petroleum asphalt; Step 2: Process of obtaining modified data under vacuum environment conditions: Weigh the selected unmodified petroleum asphalt sample of the corresponding type according to a predetermined amount and place it in the bottom container (2-3). Start the heating device (7) and the temperature control component (8-2) in the monitoring system. Ensure that the unmodified petroleum asphalt sample is heated to the predetermined temperature and then stop heating and maintain a constant temperature state at the predetermined temperature. While controlling the exhaust valve to close through the main controller (8-1) in the monitoring system, open the air extraction valve and the vacuum pump (11). The air extraction valve and the vacuum pump (11) cooperate to ensure that the sealed box (1) is in the vacuum state required by the predetermined requirements. First, start the self-driven feeding component (3) to pour the chemical modifier into the bottom container (2-3) to form a mixture. Then, start the self-driven stirring component (2-2) to stir at a predetermined stirring rate to form a chemically modified asphalt mixture. Finally, start the spectral signal receiving device (9) and the infrared spectrometer (10) to collect the infrared spectral information of the chemically modified asphalt mixture in the bottom container (2-3). Through the computer processing software, real-time monitor the consumption state of the active chemical functional groups of the modifier in the chemically modified asphalt mixture until the active functional groups of the modifier are consumed or the content of the active functional groups no longer changes, then stop stirring to obtain the required chemically modified asphalt sample. In the chemically modified asphalt sample, obtain the measured value I of the performance index of the chemically modified asphalt under the vacuum environment 真空 As the standard value; Step 3: Process of obtaining modification data under air environmental conditions: Open the sealed box (1), ensure that the air extraction valve and the vacuum pump (11) are in the closed state, repeat the operation process of Step 2, obtain the consumption state of the active chemical functional groups of the modifier in the chemically modified asphalt mixture under air environmental conditions, stop stirring until the active functional groups of the modifier are consumed or the content of the active functional groups no longer changes, obtain the required chemically modified asphalt sample, and measure the actual value I of the performance index of the chemically modified asphalt under air environmental conditions in the chemically modified asphalt sample 空气 , and calculate the difference rate of the performance indexes of the chemically modified asphalt under vacuum environmental conditions and air environmental conditions according to the formula. The calculation process is as follows: In the above formula, D is the performance difference rate; I 空气 is the measured value of the performance index of the chemically modified asphalt prepared under the air environment; I 真空 is the measured value of the performance index of the chemically modified asphalt prepared under the vacuum environment; I 空气 and I 真空 are the same performance index corresponding to different asphalt preparation conditions. The performance stability of the chemically modified asphalt against environmental factor interference is evaluated based on the specific value of the performance difference rate D. When the performance difference rate D ≤ 10%, it indicates that the performance stability of the chemically modified asphalt prepared with this type of petroleum asphalt is excellent; when the performance difference rate is 10% < D < 20%, it indicates that the performance stability of the chemically modified asphalt prepared with this type of petroleum asphalt is good; when the performance difference rate D ≥ 20%, it indicates that the performance stability of the chemically modified asphalt prepared with this type of petroleum asphalt is poor.

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