Preparation method of elastomer modified emulsified asphalt for bonding layer

Abstract

The invention relates to the technical field of asphalt preparation, in particular to a preparation method of elastomer modified emulsified asphalt for a bonding layer, which comprises the following steps: preparing modified asphalt and emulsified liquid for later use; feeding the preheated modified asphalt and the emulsified liquid into an emulsifying machine to form modified emulsified asphalt; determining the emulsification grade of the emulsification process according to the parameter fluctuation amplitude; controlling the exhaust valve to determine the opening and closing state of the exhaust hole; adjusting the stirring speed of the emulsifying device according to the viscosity of the asphalt, or confirming the reason that the modified emulsified asphalt does not meet the viscosity requirement; determining the change reason of the emulsion concentration according to the loss state of the emulsion, adjusting the flow of the emulsion when the flow of the modified asphalt is not matched with the flow of the emulsion, and starting a supplementing device when the lost emulsion exceeds an error range; and determining the time of circulating emulsification according to the viscosity of the evaporation residue, and adjusting the initial detection period. According to the invention, the adaptability and flexibility of the prepared modified emulsified asphalt are improved by adjusting emulsification cycle parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt preparation, and particularly relates to a preparation method of an elastomer-modified emulsified asphalt for a bonding layer. Background Art

[0002] Asphalt, as a pavement material, exists in a viscoelastic state within a certain temperature range. Only within the temperature range corresponding to the viscoelastic state can its normal service performance be exerted. However, within the temperature ranges corresponding to the viscous flow state and the glassy state of asphalt, its service performance rapidly decreases. If the pavement is paved, the pavement will be extremely prone to diseases and cannot meet the requirements of vehicle driving. In order to expand the viscoelastic state range of asphalt itself and expand the effective use range, the most common method is to modify asphalt. Although modified asphalt has many advantages, modified asphalt must reach the viscosity requirements for mixing and compaction at a relatively high temperature, which has certain limitations on the construction conditions and construction period, while emulsified asphalt can well make up for its deficiencies. However, emulsified asphalt is essentially just another form of asphalt, so the weakness of the small viscoelastic state range of asphalt itself has not changed at all. Modern engineering has put forward extremely high requirements for the high-temperature performance, low-temperature performance, anti-aging performance, rutting resistance, and fatigue resistance of emulsified asphalt, which has promoted the generation and development process of modified emulsified asphalt.

[0003] Chinese Patent Publication No.: CN117069960A discloses a production process of modified emulsified asphalt, including the following steps: Preparation of soap solution: Add water to a reaction vessel, heat up, add an emulsifier and an emulsification aid, then stir, and add an acid-base regulator to adjust the pH to obtain the soap solution; Modification of asphalt: Add matrix asphalt to a shear grinder, heat up to 165 - 220 °C, add an SBS modifier, a compatibilizer, and an aid, and then keep the temperature for reaction to obtain modified asphalt; (3) Emulsification of modified asphalt: Put the prepared soap solution and the prepared modified asphalt into a colloid mill to heat up for emulsification. After emulsification is completed, cool to obtain the finished product of modified emulsified asphalt. It can be seen that the production process of the modified emulsified asphalt has the following problems: The viscosity of the modified asphalt increases, and it needs to be stored at a relatively high temperature. When the high-temperature modified asphalt is directly mixed with the soap solution, the soap solution will quickly boil and vaporize, resulting in difficult emulsification. If the mixing temperature of the modified asphalt is too low, the viscosity of the asphalt is too high, and it is also very difficult to emulsify. Summary of the Invention

[0004] Therefore, the present invention provides a preparation method of an elastomer-modified emulsified asphalt for a bonding layer to overcome the problems in the prior art that the modified asphalt needs to be stored at a relatively high temperature, directly mixing with the soap solution will cause the soap solution to quickly boil and vaporize, resulting in difficult emulsification, and if the mixing temperature is too low, the viscosity of the asphalt is too high, and it is also very difficult to emulsify.

[0005] To achieve the above object, the present invention provides a method for preparing an elastomer-modified emulsified asphalt for a bonding layer, including: Adding asphalt, a modifier, a compatibilizer and an auxiliary agent into a shear grinder and stirring and mixing them to obtain a modified asphalt, and mixing an emulsifier, a stabilizer and water in proportion to prepare an emulsion for standby; Preheating the modified asphalt with the modified asphalt as the base material, and feeding the preheated modified asphalt and the emulsion into an emulsifier according to the flow rate of the modified asphalt and the flow rate of the emulsion for emulsification to form a modified emulsified asphalt; Judging whether it meets the fluctuation determination condition according to the amplitude of parameter fluctuation inside the emulsifier, and determining the emulsification level of the emulsification process; Judging the stability of the emulsification process according to the emulsification level, and correspondingly controlling the exhaust valve according to the exhaust pressure and the closing condition to determine the opening and closing state of the exhaust hole; Sampling according to the initial detection period, adjusting the stirring speed of the emulsifying device according to the viscosity range of the asphalt viscosity, or confirming whether the reason for the non-compliance of the modified emulsified asphalt with the viscosity requirement is the change in the emulsion concentration; Correspondingly confirming the reason for the change in the emulsion concentration according to the loss state of the emulsion, adjusting the emulsion flow rate when the ratio of the flow rate of the modified asphalt to the flow rate of the emulsion is mismatched, and starting the replenishing device when the lost emulsion exceeds the error range to determine the replenishing duration of the replenishing device; Detecting the viscosity of the evaporation residue of the asphalt sample to determine the timing of outputting the modified emulsified asphalt and re-emulsifying through the circulating sampling device.

[0006] Further, the process of determining the emulsification level of the emulsification process includes, Calculating the amplitude of fluctuation according to the emulsification pressure and emulsification temperature inside the emulsifier according to the initial detection period, and comparing it with the standard amplitude; If the amplitude of fluctuation is greater than or equal to the first standard amplitude, it is judged that the inside of the emulsifier is in the first emulsification level; if the amplitude of fluctuation is less than the first standard amplitude and greater than or equal to the second standard amplitude, it is judged that the inside of the emulsifier is in the second emulsification level; if the amplitude of fluctuation is less than the second standard amplitude, it is judged that the inside of the emulsifier is in the third emulsification level.

[0007] Further, when the inside of the emulsifier is in the first emulsification level, controlling the opening and closing state of the exhaust hole according to the pressure change curve, comparing the corresponding exhaust pressure with the critical pressure to control the exhaust valve to open the exhaust hole, or controlling the exhaust valve to close the exhaust hole when it meets the closing condition; The closing condition is that the derivative value corresponding to the current moment when the exhaust pressure is less than the critical pressure is less than the preset value.

[0008] Further, when the inside of the emulsifier is at the second emulsification level, samples of the modified emulsified asphalt being prepared are taken at the circulating sampling device according to the initial detection period, and the asphalt viscosity of the sample asphalt is measured. When the asphalt viscosity is not within the viscosity range, the sample asphalt is further detected, and at the same time, the stirring speed of the emulsifying device in the emulsifier is increased according to the ratio of the asphalt viscosity to the intermediate value of the viscosity range.

[0009] Further, the further detection is to detect the sample conductivity of the sample asphalt. The absolute value of the difference between the sample conductivity and the standard conductivity is compared with the difference evaluation value to determine whether the reason for the modified emulsified asphalt not meeting the viscosity requirement is a change in the emulsion concentration.

[0010] Further, when it is determined that the reason for not meeting the viscosity requirement is a change in the emulsion concentration. The duration ratio is calculated based on the exhaust duration when the exhaust valve is in the exhaust state and the closing duration when it is in the closed state, and the emulsion loss state is determined according to the duration ratio and the pressure change curve. If the duration ratio of the exhaust duration to the closing duration is greater than the preset ratio, and the derivative value corresponding to the current moment when the exhaust pressure is greater than the critical pressure is greater than the absolute value of the preset value, it is determined that the emulsion is in the first loss state. If the duration ratio of the exhaust duration to the closing duration is less than or equal to the preset ratio, or the derivative value corresponding to the current moment when the exhaust pressure is greater than the critical pressure is less than the absolute value of the preset value, it is determined that the emulsion is in the second loss state.

[0011] Further, when the emulsion is in the second loss state, it is determined that the reason for the change in the emulsion concentration is that the ratio of the modified asphalt flow rate to the emulsion flow rate is mismatched. When the emulsion is in the first loss state, it is determined that the reason for the change in the emulsion concentration is that the emulsion lost when the exhaust valve is opened exceeds the error range.

[0012] Further, when the ratio of the flow rates is mismatched, the emulsion input flow rate is increased according to the duration ratio and the derivative value of the pressure change curve. When the lost emulsion exceeds the error range, the replenishing device is opened to determine the replenishing duration of the replenishing device.

[0013] Further, when the inside of the emulsifier is at the third emulsification level, the evaporation residue viscosity of the asphalt sample is detected. When the evaporation residue viscosity is within the viscosity requirement range, the modified emulsified asphalt is output through the circulating sampling device. When the evaporation residue viscosity is lower than the viscosity requirement range, the modified emulsified asphalt is cycled into the emulsifier through the circulating sampling device for circulating emulsification.

[0014] Further, during the cyclic emulsification, the initial detection period is reduced according to the ratio of the evaporation residue viscosity to the median value of the viscosity requirement range.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: modification before emulsification is suitable for various modifiers, and the modifiers react fully with asphalt, achieving the best modification effect and being applicable to pavement construction with high performance requirements; SBS is a thermoplastic elastomer. After asphalt is modified with SBS, it has higher high-temperature stability, which is beneficial to improving the rutting resistance of asphalt pavement. At the same time, it has better low-temperature performance, water damage resistance, anti-aging performance, creep resistance, etc.; a single cationic emulsifier has poor emulsification effect on SBS, while when a certain cationic emulsifier, non-ionic emulsifier, and anionic emulsifier are compounded in a ratio of 3:1:1, the emulsification effect is significantly improved; it avoids diseases such as interlayer structure displacement and low-temperature cracking when repairing the road pavement for the bonding layer, and regulates the emulsification process to solve the problem that the viscosity of modified asphalt is too high and difficult to emulsify, which has high requirements for equipment and emulsification process during processing.

[0016] Further, at the beginning of emulsification inside the emulsifier, the modified asphalt and the emulsion are mixed, and the soap solution quickly boils and vaporizes, affecting the pressure and changing the soap solution concentration; the present invention determines whether the emulsification process is in a stable state through the fluctuation range of the emulsification pressure and emulsification temperature, takes corresponding measures or further analyzes, keeps the asphalt and emulsifier within the optimal temperature range to ensure that the emulsifier is fully dispersed and a stable emulsion is formed, and at the same time maintains a stable pressure in the colloid mill to avoid excessive shearing or insufficient emulsification of the emulsion, ensuring the stability of emulsification and the modification effect and avoiding material caking or unevenness.

[0017] Further, the viscosity of the modified asphalt increases, and it needs to be stored at a relatively high temperature (generally above 160°C). When the relatively high-temperature modified asphalt is directly mixed with the soap solution (60 - 70°C), the soap solution will quickly boil and vaporize, resulting in difficult emulsification. If the mixing temperature of the modified asphalt is too low, the viscosity of the asphalt is too high, and it is also very difficult to emulsify; the present invention controls the opening and closing state of the exhaust hole penetrating the outer shell of the emulsifier through the set exhaust valve, controls the opening and closing state of the exhaust hole according to the pressure change curve, reduces the emulsification pressure increased by the vaporized soap solution by opening the exhaust hole, and at the same time, when the change curve meets the closing condition, determines that the decrease rate of the exhaust pressure is relatively large according to the derivative value corresponding to the current moment, predicts the decreasing trend of the vaporized soap solution, and controls the exhaust valve to close the exhaust hole, avoiding the adverse effect on the emulsification process of the modified asphalt caused by the repeated opening and closing of the exhaust hole due to the increase of the vaporized soap solution again after the exhaust hole is closed, which increases the fluctuation range of the emulsification pressure, and at the same time increases the accuracy of determining the emulsification level.

[0018] Furthermore, the higher the viscosity of the modified asphalt, the more difficult it is to emulsify. It is necessary to preheat the modified asphalt to an appropriate temperature (generally 120-160 °C) to soften it and reduce the viscosity. The boiling and gasification of the soap solution affect the emulsification pressure inside the emulsifier. When the exhaust hole is opened, the emulsification pressure is reduced, but it also causes the loss of the gasified soap solution. When the emulsification process inside the emulsifier is unstable, the present invention samples and detects the asphalt viscosity of the modified emulsified asphalt, and online detects the conductivity of the asphalt sample to judge the change trend of the concentration of the emulsion while adjusting the stirring speed of the modified emulsified asphalt still being prepared. Asphalt itself does not have conductivity and belongs to an electrically insulating material. The change trend of the emulsion concentration in the emulsification process can be determined through the conductivity of the asphalt sample. The loss state of the emulsion is determined according to the specific exhaust situation of the exhaust hole, and the emulsifier flow rate is dynamically adjusted according to the asphalt flow rate and the loss state of the emulsion to maintain the emulsifier concentration, avoid the coalescence of the modified emulsified asphalt to form larger particles, reduce the uniformity and stability of the emulsion, and improve the polymerization reaction rate and product quality of the prepared modified emulsified asphalt emulsion.

[0019] Furthermore, the higher the viscosity of the evaporation residue of the modified emulsified asphalt, the better the waterproof performance and bonding performance of the bonding layer. The present invention can sample and detect the viscosity of the evaporation residue when the emulsification process inside the emulsifier is stable, output the modified emulsified asphalt or perform cyclic emulsification on the modified emulsified asphalt according to the detection result, accurately determine the cyclic timing of the modified emulsified asphalt, and adjust the determination standard of the emulsification level for determining the emulsification process, and more closely monitor and control the emulsification process during cyclic emulsification; at the same time, it can maintain the emulsion concentration by supplementing the emulsion, accurately control the concentration of the emulsifier to obtain the best emulsification effect, thereby dynamically adjusting the emulsification parameters according to different requirements to change the properties of the modified emulsified asphalt, being able to adapt to the property requirements of the modified emulsified asphalt for different application scenarios, customize the emulsification state of the modified emulsified asphalt, and improve the adaptability and flexibility of preparing the modified emulsified asphalt. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flowchart of the method for elastomer-modified emulsified asphalt used in the bonding layer in the embodiment of the present invention; Figure 2 is a schematic structural diagram of the emulsifier in the embodiment of the present invention; Figure 3 is a schematic flow diagram of the preparation method of the elastomer-modified emulsified asphalt in the embodiment of the present invention; Figure 4 is a schematic flow diagram of determining the emulsification level in the embodiment of the present invention; In the figure: 1 - emulsification device, 2 - supplement device, 3 - cyclic sampling device, 4 - solenoid valve, 5 - exhaust valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To make the objectives and advantages of the present invention more clear and understandable, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only for explaining the present invention and are not used to limit the present invention.

[0022] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0023] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0024] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Please refer to Figures 1 - 4 as shown in Figure 1 the flowchart of the method for elastomer-modified emulsified asphalt for the bonding layer in the embodiment of the present invention; Figure 2 the structural schematic diagram of the emulsifying machine in the embodiment of the present invention; Figure 3 the process schematic diagram of the preparation method of elastomer-modified emulsified asphalt in the embodiment of the present invention; Figure 4 the process schematic diagram of determining the emulsification level in the embodiment of the present invention.

[0026] The present invention provides a preparation method for elastomer-modified emulsified asphalt for the bonding layer, including: Step S1: Using natural rubber and thermoplastic elastomeric polymers as modifiers, adding asphalt, modifiers, compatibilizers, and other additives to a shear grinder and stirring and mixing them. Through solvent dissolution and mechanical shearing, they are evenly distributed in the asphalt in the form of fine particles to obtain modified asphalt; Step S2: Mixing emulsifier, stabilizer, and water in a certain proportion to make an emulsion for standby. The emulsion is also called soap solution; Step S3: Preheat it with modified asphalt as the base material, and feed the preheated modified asphalt and the emulsion into an emulsifier according to the flow rates of the modified asphalt and the emulsion for emulsification, cutting the modified asphalt into tiny droplets and dispersing them in the emulsion to form modified emulsified asphalt; Step S4: Determine whether it meets the fluctuation determination condition based on the parameter fluctuation range inside the emulsifier, and determine the emulsification level of the emulsification process; Step S5: Determine the stability of the emulsification process according to the emulsification level, and correspondingly control the exhaust valve based on the exhaust pressure and the closing condition to determine the opening and closing state of the exhaust hole; Step S6: Take samples according to the initial detection period, adjust the stirring speed of the emulsification device according to the viscosity range of the asphalt viscosity, or confirm whether the reason for the non - compliance of the modified emulsified asphalt with the viscosity requirement is the change in the emulsion concentration; Step S7: Confirm the reason for the change in the emulsion concentration according to the loss state of the emulsion, adjust the emulsion flow rate when the ratio of the modified asphalt flow rate to the emulsion flow rate is not matched, and turn on the replenishment device when the lost emulsion exceeds the error range to determine the replenishment duration of the replenishment device; Step S8: Detect the viscosity of the evaporation residue of the asphalt sample to determine the timing of outputting the modified emulsified asphalt and re - emulsifying through the circulating sampling device.

[0027] The modified production process of emulsified asphalt can be divided into four categories: 1. Add a latex modifier after making the emulsified asphalt, that is, modify after emulsification; 2. Incorporate the latex modifier into the emulsifier aqueous solution, and then enter a colloid mill with asphalt to make modified emulsified asphalt; 3. Put the latex modifier, the emulsifier aqueous solution, and asphalt into the colloid mill simultaneously to make modified emulsified asphalt (the second and third methods can be collectively referred to as modifying while emulsifying); 4. Emulsify the modified asphalt to make emulsified modified asphalt, that is, modify first and then emulsify.

[0028] In this embodiment, the method of modifying first and then emulsifying is adopted. The asphalt modifier is a block copolymer SBS, and the asphalt emulsifier is prepared by compounding a cationic emulsifier, a non - ionic emulsifier, and an anionic emulsifier in a ratio of 3:1:1.

[0029] Specifically, modification before emulsification is suitable for a variety of modifiers. The modifier reacts fully with asphalt, achieving the best modification effect and being applicable to pavement construction with high performance requirements. SBS is a thermoplastic elastomer. After asphalt is modified with SBS, it has higher high-temperature stability, which is beneficial to improving the rutting resistance of asphalt pavements. At the same time, it has better low-temperature performance, water damage resistance, anti-aging performance, creep resistance, etc. A single cationic emulsifier has poor emulsification effect on SBS. However, when a certain cationic emulsifier, non-ionic emulsifier, and anionic emulsifier are compounded in a ratio of 3:1:1, the emulsification effect is significantly improved. It is necessary to avoid diseases such as interlayer structure displacement and low-temperature cracking when repairing the road pavement for the bonding layer, and regulate the emulsification process to solve the problem that the modified asphalt has high viscosity and is difficult to emulsify, which has high requirements for equipment and emulsification process during processing.

[0030] Real-time detect the emulsification pressure and emulsification temperature inside the emulsifier, and calculate the fluctuation range of the emulsification pressure and emulsification temperature according to the initial detection period to determine whether it meets the fluctuation determination condition. The fluctuation range is equal to the absolute value of the difference between the emulsification pressure and emulsification temperature detected in each initial detection period and the corresponding emulsification pressure and emulsification temperature in the previous initial detection period. If the fluctuation range is greater than or equal to the first standard range, it is determined that the emulsification parameters do not meet the fluctuation determination condition, and the inside of the emulsifier is in the first emulsification level. If the fluctuation range is less than the first standard range and greater than or equal to the second standard range, it is determined that the emulsification parameters do not meet the fluctuation determination condition, and the inside of the emulsifier is in the second emulsification level. If the fluctuation range is less than the second standard range, it is determined that the emulsification parameters meet the fluctuation determination condition, and the inside of the emulsifier is in the third emulsification level. Among them, the second standard range is less than the first standard range. The first standard range and the second standard range of the emulsification pressure are 0.3 MPa and 0.05 MPa, and the first standard range and the second standard range of the emulsification temperature are 5 °C and 2 °C.

[0031] Specifically, when emulsification starts inside the emulsifier, the modified asphalt and the emulsion liquid are mixed, and the soap liquid quickly boils and vaporizes, affecting the pressure and changing the soap liquid concentration. The present invention determines whether the emulsification process is in a stable state through the fluctuation range of the emulsification pressure and emulsification temperature, takes corresponding measures or further analyzes, keeps the asphalt and the emulsifier in the optimal temperature range to ensure that the emulsifier is fully dispersed and a stable emulsion liquid is formed, and at the same time maintains a stable pressure in the colloid mill to avoid excessive shearing or insufficient emulsification of the emulsion, ensuring the stability of emulsification and the modification effect, and avoiding material caking or unevenness.

[0032] Detect the exhaust pressure received by the exhaust valve provided at the exhaust port, draw a pressure change curve, and find the derivative function of the change curve. When the inside of the emulsifier is at the first emulsification level, emulsification just starts, the modified asphalt and the emulsion are mixed, and the soap solution rapidly boils and vaporizes, affecting the pressure and changing the concentration of the soap solution. If the exhaust pressure corresponding to the pressure change curve at any moment is greater than or equal to the critical pressure, control the exhaust valve to open the exhaust hole. If the exhaust pressure corresponding to the pressure change curve at any moment is less than the critical pressure, control the exhaust valve to close the exhaust hole when the change curve meets the closing condition. The closing condition is that the derivative value corresponding to the current moment when the exhaust pressure is less than the critical pressure is less than the preset value. Among them, the critical pressure is 0.5 MPa, and the preset value is -0.4.

[0033] Specifically, the viscosity of the modified asphalt increases and it needs to be stored at a relatively high temperature (generally above 160 °C). Mixing the high-temperature modified asphalt directly with the soap solution (60 - 70 °C) will cause the soap solution to rapidly boil and vaporize, making emulsification difficult. If the mixing temperature of the modified asphalt is too low, the viscosity of the asphalt is too high and it is also difficult to emulsify. The present invention controls the opening and closing state of the exhaust hole penetrating the outer shell of the emulsifier through the provided exhaust valve, controls the opening and closing state of the exhaust hole according to the pressure change curve, reduces the emulsification pressure increased by the vaporized soap solution by opening the exhaust hole, and at the same time, when the change curve meets the closing condition, determines that the decreasing speed of the exhaust pressure is relatively large according to the derivative value corresponding to the current moment, predicts the decreasing trend of the vaporized soap solution and controls the exhaust valve to close the exhaust hole, avoiding the adverse effect on the emulsification process of the modified asphalt caused by the repeated opening and closing of the exhaust hole due to the increase of the vaporized soap solution again after the exhaust hole is closed, and at the same time increasing the accuracy of the determination of the emulsification level.

[0034] When the inside of the emulsifier is at the second emulsification level, sample the prepared modified emulsified asphalt at the circulating sampling device according to the initial detection period, and measure the asphalt viscosity of the sample asphalt with an Engler viscometer or a rotational viscometer. If the asphalt viscosity is within the viscosity range, it is determined that the modified emulsified asphalt in emulsification meets the viscosity requirement, and continue to determine the emulsification level inside the emulsifier. If the asphalt viscosity is not within the viscosity range, it is determined that the modified emulsified asphalt in emulsification does not meet the viscosity requirement, further detect the sample asphalt, and at the same time increase the stirring speed of the emulsification device in the emulsifier according to the ratio of the asphalt viscosity to the intermediate value of the viscosity range. Among them, the viscosity range is 1400 - 1600 mPa·s.

[0035] Determine the reason why the modified emulsified asphalt does not meet the viscosity requirement, and detect the sample conductivity of the sampled sample asphalt with an industrial conductivity meter. If the absolute value of the difference between the conductivity of the sample and the standard conductivity is greater than the difference evaluation value, it is determined that the conductivity of the sample passes the detection; If the absolute value of the difference between the conductivity of the sample and the standard conductivity is greater than the difference evaluation value, it is determined that the conductivity of the sample fails the detection, and the reason why the modified emulsified asphalt does not meet the viscosity requirement is that the concentration of the emulsion has changed; Among them, the standard conductivity and the difference evaluation value are preset values set according to the average conductivity and the average difference of the historical conductivity data of the modified emulsified asphalt that has passed the quality inspection.

[0036] When it is determined that the reason why the modified emulsified asphalt does not meet the viscosity requirement is that the concentration of the emulsion has changed, it is judged whether the emulsion lost when the exhaust valve is opened exceeds the error range. According to the exhaust duration and the exhaust state of the exhaust valve, the loss state of the emulsion is determined, and the exhaust duration when the exhaust valve is in the exhaust state and the closing duration when it is in the closed state are detected. If the ratio of the exhaust duration to the closing duration is greater than the preset ratio, and the derivative value corresponding to the current moment when the exhaust pressure is greater than the critical pressure is greater than the absolute value of the preset value, it is determined that the emulsion is in the first loss state; If the ratio of the exhaust duration to the closing duration is less than or equal to the preset ratio, or the derivative value corresponding to the current moment when the exhaust pressure is greater than the critical pressure is less than the absolute value of the preset value, it is determined that the emulsion is in the second loss state; Among them, the preset ratio is equal to 45%.

[0037] If the emulsion is in the second loss state, it is determined that the reason for the change in the emulsion concentration is that the ratio of the modified asphalt flow rate to the emulsion flow rate is mismatched, and the emulsion flow rate is adjusted; Specifically, the emulsion inflow rate is increased according to the ratio of the product of the ratio of the exhaust duration to the closing duration and the derivative value corresponding to the current moment when the exhaust pressure is greater than the critical pressure to the product of the preset ratio and the absolute value of the preset value; If the emulsion is in the first loss state, it is determined that the reason for the change in the emulsion concentration is that the emulsion lost when the exhaust valve is opened exceeds the error range, and the replenishment device is opened; Specifically, the replenishment duration of the replenishment device is determined according to the exhaust duration of the exhaust valve, the derivative value corresponding to the current moment when the exhaust pressure is greater than the critical pressure, and the flow rate of the replenishment device.

[0038] Specifically, the greater the viscosity of the modified asphalt, the more difficult it is to emulsify. It is necessary to preheat the modified asphalt to an appropriate temperature (generally 120-160 °C) to soften it and reduce the viscosity. The boiling and gasification of the soap solution affect the emulsification pressure inside the emulsifier. When the exhaust hole is opened, the emulsification pressure is reduced, but the gasified soap solution is also lost. When the emulsification process inside the emulsifier is unstable, the present invention samples and detects the asphalt viscosity of the modified emulsified asphalt, and online detects the conductivity of the asphalt sample to judge the change trend of the concentration of the emulsion while adjusting the stirring speed of the modified emulsified asphalt still being prepared. Asphalt itself does not have conductivity and belongs to an electrically insulating material. The change trend of the emulsion concentration in the emulsification process can be determined through the conductivity of the asphalt sample. The loss state of the emulsion is determined according to the specific exhaust situation of the exhaust hole, and the emulsifier flow rate is dynamically adjusted according to the asphalt flow rate and the loss state of the emulsion to maintain the emulsifier concentration, avoid the coalescence of the modified emulsified asphalt to form larger particles, reduce the uniformity and stability of the emulsion, and improve the polymerization reaction rate and product quality of the prepared modified emulsified asphalt emulsion.

[0039] When the inside of the emulsifier is at the third emulsification level, sample and detect the viscosity of the evaporation residue of the modified emulsified asphalt to determine whether to recycle it into the emulsifier for re-emulsification. If the viscosity of the evaporation residue is within the viscosity requirement range, output the modified emulsified asphalt through the circulating sampling device. If the viscosity of the evaporation residue is lower than the viscosity requirement range, recycle the modified emulsified asphalt into the emulsifier through the circulating sampling device for re-emulsification, and at the same time call back the initial detection period. Specifically, reduce the initial detection period according to the ratio of the viscosity of the evaporation residue to the intermediate value of the viscosity requirement range. During the circulating input emulsification process of this embodiment, keep the emulsifier concentration between 2% and 5%.

[0040] Specifically, the greater the viscosity of the evaporation residue of the modified emulsified asphalt, the better the waterproof performance and bonding performance of the bonding layer. The present invention can sample and detect the viscosity of the evaporation residue when the emulsification process inside the emulsifier is stable, output the modified emulsified asphalt according to the detection result or recycle the modified emulsified asphalt for emulsification, accurately determine the recycling timing of the modified emulsified asphalt, and adjust the determination standard of the emulsification level of the emulsification process, and more closely monitor and control the emulsification process during recycling emulsification; at the same time, it can maintain the emulsion concentration by supplementing the emulsion, accurately control the concentration of the emulsifier to obtain the best emulsification effect, so as to dynamically adjust the emulsification parameters according to different requirements to change the properties of the modified emulsified asphalt, be able to adapt to the property requirements of the modified emulsified asphalt in different application scenarios, customize the emulsification state of the modified emulsified asphalt, and improve the adaptability and flexibility of preparing the modified emulsified asphalt.

[0041] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, those skilled in the art can easily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing an elastomer-modified emulsified asphalt for a bonding layer, characterized in that: include: Add asphalt, modifier, compatibilizer and auxiliary agent into a shearing grinder, stir and mix to obtain modified asphalt, and mix emulsifier, stabilizer and water in proportion to obtain emulsion for use; Using modified asphalt as a base material to preheat it, and sending the preheated modified asphalt and emulsion into an emulsifier according to the flow rate of modified asphalt and the flow rate of emulsion for emulsification to form modified emulsified asphalt; Calculate the internal parameter fluctuation range of the emulsifier according to the initial detection cycle to determine whether it meets the fluctuation judgment conditions and determine the emulsification level of the emulsification process; The stability of the emulsification process is determined according to the emulsification level, and the exhaust valve is controlled to determine the opening and closing state of the exhaust hole according to the exhaust pressure and closing conditions; Take samples according to the initial test cycle, adjust the stirring speed of the emulsifier according to the viscosity range of the asphalt, or confirm whether the reason why the modified emulsified asphalt does not meet the viscosity requirements is due to changes in the emulsion concentration; According to the loss state of the emulsion, the reason for the change in the emulsion concentration is confirmed accordingly. When the ratio of the modified asphalt flow rate to the emulsion flow rate does not match, the emulsion flow rate is adjusted. When the lost emulsion exceeds the error range, the replenishing device is turned on and the replenishing time of the replenishing device is determined. Detect the viscosity of the evaporation residue of the asphalt sample, determine the timing of outputting the modified emulsified asphalt and re-emulsification through the circulating sampling device, and adjust the initial detection cycle.

2. The method for preparing the elastomer-modified emulsified asphalt for the bonding layer according to claim 1, characterized in that: The process of determining the emulsification grade of the emulsification process includes, Calculate the fluctuation range according to the emulsification pressure and emulsification temperature inside the emulsifier according to the initial test cycle and compare it with the standard range; If the fluctuation amplitude is greater than or equal to the first standard amplitude, it is judged that the interior of the emulsifier is at the first emulsification level; if the fluctuation amplitude is less than the first standard amplitude, and the fluctuation amplitude is greater than or equal to the second standard amplitude, it is judged that the interior of the emulsifier is at the second emulsification level; if the fluctuation amplitude is less than the second standard amplitude, it is judged that the interior of the emulsifier is at the third emulsification level.

3. The method for preparing the elastomer-modified emulsified asphalt for the bonding layer according to claim 2, characterized in that: When the emulsifier is at the first emulsification level, the opening and closing state of the exhaust hole is controlled according to the pressure change curve, and the corresponding exhaust pressure is compared with the critical pressure to control the exhaust valve to open the exhaust hole, or the exhaust valve is controlled to close the exhaust hole when the closing condition is met; The closing condition is that the exhaust pressure is less than the critical pressure and the derivative value corresponding to the current moment is less than a preset value.

4. The method for preparing the elastomer-modified emulsified asphalt for the bonding layer according to claim 2, characterized in that: When the interior of the emulsifier is at the second emulsification level, the modified emulsified asphalt being prepared is sampled at the circulating sampling device according to the initial detection cycle to measure the asphalt viscosity of the sample asphalt; When the asphalt viscosity is not within the viscosity range, the sample asphalt is further tested, and the stirring speed of the emulsifying device in the emulsifier is increased according to the ratio of the asphalt viscosity to the middle value of the viscosity range.

5. The method for preparing the elastomer-modified emulsified asphalt for the bonding layer according to claim 4, characterized in that: The further detection is to detect the sample conductivity of the sample asphalt, Compare the absolute value of the difference between the sample conductivity and the standard conductivity with the difference evaluation value to determine whether the reason why the modified emulsified asphalt does not meet the viscosity requirements is due to a change in the emulsion concentration.

6. The method for preparing the elastomer-modified emulsified asphalt for the bonding layer according to claim 5, characterized in that: When it is determined that the reason for not meeting the viscosity requirements is a change in the emulsion concentration, The time ratio is calculated according to the exhaust time of the exhaust valve in the exhaust state and the closing time in the closing state, and the emulsion loss state is determined according to the time ratio and the pressure change curve; If the ratio of the exhaust time to the closing time is greater than the preset ratio, and the derivative value corresponding to the current moment when the exhaust pressure is greater than the critical pressure is greater than the absolute value of the preset value, it is determined that the emulsion is in the first loss state; If the ratio of the exhaust time to the closing time is less than or equal to the preset ratio, or the derivative value corresponding to the current moment when the exhaust pressure is greater than the critical pressure is less than the absolute value of the preset value, it is determined that the emulsion is in the second loss state.

7. The method for preparing the elastomer-modified emulsified asphalt for the bonding layer according to claim 6, characterized in that: When the emulsion is in the second loss state, it is determined that the reason for the change in the emulsion concentration is that the ratio of the modified asphalt flow rate to the emulsion flow rate does not match; When the emulsion is in the first loss state, it is determined that the reason for the change in the emulsion concentration is that the emulsion lost when the exhaust valve is opened exceeds the error range.

8. The method for preparing the elastomer-modified emulsified asphalt for the bonding layer according to claim 7, characterized in that: When the flow ratio does not match, the emulsion flow rate is increased according to the time ratio and the derivative value of the pressure change curve; When the lost emulsion exceeds the error range, the replenishing device is turned on to determine the replenishing time of the replenishing device.

9. The method for preparing the elastomer-modified emulsified asphalt for the bonding layer according to claim 2, characterized in that: When the emulsifier is at the third emulsification level, the viscosity of the evaporation residue of the asphalt sample is tested. When the viscosity of the evaporation residue is within the required viscosity range, the modified emulsified asphalt is output through a circulating sampling device; When the viscosity of the evaporation residue is lower than the required viscosity range, the modified emulsified asphalt is circulated into the emulsifier through the circulating sampling device for circulated emulsification.

10. The method for preparing the elastomer-modified emulsified asphalt for the bonding layer according to claim 9, characterized in that: During the cyclic emulsification, the initial detection period is reduced according to the ratio of the viscosity of the evaporation residue to the middle value of the viscosity requirement range.

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