Emulsified asphalt quality grading method and system based on viscosity-temperature curve

Abstract

The present application relates to the technical field of road engineering material detection, and particularly relates to an emulsified asphalt quality grading method and system based on viscosity-temperature curve, which comprises the following steps: setting multiple measurement temperature points in a selected temperature range, and measuring the rotational paddle viscosity value of emulsified asphalt at each measurement temperature point; constructing a viscosity-temperature curve according to the corresponding relationship between the rotational paddle viscosity value and the measurement temperature point; identifying all fluctuation peaks on the viscosity-temperature curve, and determining the temperature positions corresponding to each fluctuation peak; calculating the difference value of the rotational paddle viscosity value between adjacent temperature points of the fluctuation peak, dividing the fluctuation peak type according to a preset difference value threshold, and the fluctuation peak type includes slight fluctuation peak and oscillation fluctuation peak; and outputting the emulsified asphalt quality grading result based on the fluctuation peak type and quantity. Through the present application, the problem that the existing emulsified asphalt quality evaluation method cannot evaluate the quality stability of emulsified asphalt changing with temperature is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of road engineering material testing technology, and in particular to a method and system for quality grading of emulsified asphalt based on viscosity-temperature curves. Background Technology

[0002] In recent years, preventative maintenance technologies such as chip seal and micro-surfacing have been widely used in highway maintenance due to their advantages of fast construction speed and low cost. Emulsified asphalt, as a crucial binder and tack coat material in these technologies, directly affects the spraying, mixing, and molding effects due to its quality stability. In engineering practice, some emulsified asphalt exhibits poor quality stability, experiencing problems such as emulsion separation and storage demulsification within a short period. This easily leads to fluctuations in bonding performance during construction, subsequently inducing pavement defects such as loosening and bleeding. Furthermore, the performance and stability of emulsified asphalt vary significantly under different temperature conditions, and the temperature during construction stages such as storage, transportation, spraying, and mixing is difficult to control precisely, making the impact of temperature changes on construction quality even more pronounced. Viscosity, as one of the key indicators of emulsified asphalt, is closely related to its sprayability and mixability and is an important parameter reflecting the material's state. Therefore, accurately evaluating the viscosity and quality stability of emulsified asphalt is of great significance.

[0003] In terms of existing technology, the Engla viscosity standard is commonly used in my country's highway industry standard (JTG 3410-2025) to evaluate the viscosity of emulsified asphalt. However, its test results are concentrated within a relatively small range, and its ability to distinguish between emulsified asphalt with different viscosities is limited. Although rotary paddle viscosity index has been introduced abroad, current Chinese standards have not yet specified the rotary paddle viscosity test and evaluation index for emulsified asphalt, indicating a relatively weak foundation in related research and application. On the other hand, the current standards' methods for evaluating the storage stability of emulsified asphalt are mainly aimed at room temperature conditions, making it difficult to reflect the changes in the quality stability of emulsified asphalt under different temperature conditions. Research and practice show that the dispersion stability of emulsifiers, water, and asphalt in the emulsified asphalt system varies significantly at different temperatures. These changes can be reflected by the characteristics of viscosity changes with temperature. Emulsified asphalt with good quality stability shows a smooth decreasing trend in viscosity with increasing temperature, while emulsified asphalt with poor quality stability is prone to abnormal fluctuations in viscosity with temperature changes. Therefore, existing technology lacks an effective method that can comprehensively characterize the viscosity changes of emulsified asphalt within different temperature ranges and evaluate its quality stability accordingly.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the general background of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention provides a method and system for quality grading of emulsified asphalt based on viscosity-temperature curves, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for quality grading of emulsified asphalt based on viscosity-temperature curves, the method comprising: Multiple measurement temperature points are set within a selected temperature range, and the rotary paddle viscometer is used to determine the rotary paddle viscosity value of the emulsified asphalt at each of the measurement temperature points. A viscosity-temperature curve is constructed based on the correspondence between the viscosity value of the rotating propeller and the measurement temperature point; Identify all fluctuation peaks on the viscosity-temperature curve and determine the temperature position corresponding to each fluctuation peak. The fluctuation peak is defined as the viscosity value of the rotating propeller at the current temperature being greater than the viscosity value of the rotating propeller at the previous temperature. Calculate the difference in the viscosity value of the rotating paddle between adjacent temperature points of the fluctuation peak, and classify the fluctuation peak type according to a preset difference threshold. The fluctuation peak type includes slight fluctuation peak and oscillating fluctuation peak. Based on the type and number of fluctuation peaks, the quality grading results of emulsified asphalt are output.

[0007] Furthermore, the fluctuation peak types are classified according to a preset difference threshold, including: If the difference between the viscosity value of the rotating propeller at the fluctuation peak and the viscosity value of the rotating propeller at the previous temperature is less than 5, it is recorded as the slight fluctuation peak. If the difference between the viscosity value of the rotating propeller at the fluctuation peak and the viscosity value of the rotating propeller at the previous temperature is greater than or equal to 5, it is recorded as the oscillation fluctuation peak.

[0008] Furthermore, the quality grading results of emulsified asphalt include: Grade A is characterized by a gradually decreasing viscosity-temperature curve that is smooth or has only one slight fluctuation peak. Grade B is characterized by the presence of only one of the aforementioned oscillation peaks, or only two of the aforementioned slight fluctuation peaks, or the presence of one of the aforementioned oscillation peaks and one of the aforementioned slight fluctuation peaks; Grade C is characterized by the presence of two or more of the aforementioned oscillation peaks, or three or more of the aforementioned slight fluctuation peaks, or one of the aforementioned oscillation peaks and two of the aforementioned slight fluctuation peaks.

[0009] Furthermore, the selected temperature range is 20°C to 70°C, and the multiple measurement temperature points are evenly distributed at 5°C intervals.

[0010] Furthermore, after each of the measured temperature points reaches the test temperature, the test program is started and enters operation. Within 2 to 10 minutes after the operation, the viscosity value of the rotating paddle is read and recorded from the display, and the viscosity value of the rotating paddle is recorded with an accuracy of 0.1 mPa·s.

[0011] Furthermore, the emulsified asphalt samples are placed in a water bath at a test temperature of ±3℃ after sampling.

[0012] Furthermore, before constructing the viscosity-temperature curve, the viscosity values ​​of the rotating propeller corresponding to each of the measured temperature points are smoothed. The smoothing process includes using a moving average method or a curve fitting method to eliminate the influence of test noise on the identification of the fluctuation peak.

[0013] Furthermore, when the viscosity-temperature curve gradually decreases with increasing temperature and the overall change is smooth without identifying any fluctuation peaks, the quality grading result of the emulsified asphalt is directly determined to be Grade A.

[0014] A quality grading system for emulsified asphalt based on viscosity-temperature curves, the system comprising: The viscosity measurement module allows setting multiple measurement temperature points within a selected temperature range and using a rotary paddle viscometer to measure the rotary paddle viscosity value of emulsified asphalt at each measurement temperature point. The curve construction module constructs a viscosity-temperature curve based on the correspondence between the viscosity value of the rotating propeller and the measurement temperature point; The peak identification module identifies all fluctuation peaks on the viscosity-temperature curve and determines the temperature position corresponding to each fluctuation peak. A fluctuation peak is defined as the current temperature at which the viscosity value of the rotating propeller is greater than the previous temperature. The difference calculation module calculates the difference in the viscosity of the rotating propeller between adjacent temperature points of the fluctuation peak, and classifies the fluctuation peak type according to the preset difference threshold. The fluctuation peak type includes slight fluctuation peak and oscillating fluctuation peak. The quality grading module outputs the quality grading results of emulsified asphalt based on the type and number of fluctuation peaks.

[0015] Furthermore, the difference calculation module includes: The slight fluctuation identification unit records a slight fluctuation peak if the difference between the rotating propeller viscosity value of the fluctuation peak and the rotating propeller viscosity value at the previous temperature is less than 5. The oscillation identification unit records an oscillation peak if the difference between the viscosity value of the rotating propeller at the oscillation peak and the viscosity value of the rotating propeller at the previous temperature is greater than or equal to 5.

[0016] The technical solution of this invention can achieve the following technical effects: By accurately identifying and classifying fluctuation peaks in viscosity-temperature curves, classifying these peaks as slight fluctuation peaks or oscillating fluctuation peaks based on preset difference thresholds, and automatically outputting quantitative grading results according to the type and number of fluctuation peaks, this method solves the technical problems of existing emulsified asphalt quality assessment methods being unable to evaluate the quality stability of emulsified asphalt as it changes with temperature, and the insufficient detection of temperature-dependent unstable behavior and vague grading standards caused by relying on static single parameters or subjective experience judgments. This achieves more objective, automated, and high-precision quality monitoring.

[0017] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the process for quality grading of emulsified asphalt based on viscosity-temperature curves. Figure 2 A schematic diagram of the viscosity-temperature profile for evaluating Grade A; Figure 3 A schematic diagram of the viscosity-temperature profile for evaluating grade B. Figure 4 A schematic diagram of the viscosity-temperature profile for evaluating grade C; Figure 5 This is a schematic diagram of the viscosity-temperature curve corresponding to Example 3. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] Example 1; like Figure 1 As shown, this application provides a method for quality grading of emulsified asphalt based on viscosity-temperature curves, the method comprising: S10: Set multiple measurement temperature points within the selected temperature range, and use a rotary paddle viscometer to determine the rotary paddle viscosity value of emulsified asphalt at each measurement temperature point. S20: Construct a viscosity-temperature curve based on the correspondence between the viscosity value of the rotating propeller and the measurement temperature point; S30: Identify all fluctuation peaks on the viscosity-temperature curve and determine the temperature position corresponding to each fluctuation peak. A fluctuation peak is defined as the current propeller viscosity value at the current temperature being greater than the previous propeller viscosity value at the previous temperature. S40: Calculate the difference in the viscosity of the rotating propeller between adjacent temperature points of the fluctuation peak, and classify the fluctuation peak type according to the preset difference threshold. The fluctuation peak type includes slight fluctuation peak and oscillating fluctuation peak. S50: Outputs the quality grading results of emulsified asphalt based on the type and number of fluctuation peaks.

[0023] Specifically, firstly, emulsified asphalt samples were obtained according to the method in "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" T0602. The samples were then kept warm in a water bath environment with the same temperature as the target test and an allowable deviation of ±3℃ to ensure uniform temperature and avoid viscosity reading drift due to temperature differences. Subsequently, multiple measurement temperature points were set within a selected temperature range for rotary paddle viscosity testing. The preferred temperature range was 20℃ to 70℃, with measurement temperature points set sequentially at 5℃ intervals: 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, and 70℃. First, a test was conducted at 20℃, followed by progressively increasing the temperature to ensure the comparability and continuity of the curves. For viscosity testing, a rotary paddle viscometer was preferred. After each measurement temperature point reached the test temperature, the test program was started, and the rotary paddle viscosity value at that temperature point was read and recorded from the display within 2 to 10 minutes of operation, accurate to 0.1 mPa·s. After completing all temperature point tests, the corresponding rotary paddle viscosity values ​​were mapped to construct a viscosity-temperature curve for the emulsified asphalt. The curve was formed using multi-point rotary paddle viscosity data within the temperature range, and the fluctuation peaks in the curve were used as... This provides a direct basis for evaluating and classifying quality stability, transforming the stability differences that vary with temperature into identifiable, countable, and classifiable objective characteristics. Specifically, the curve is scanned in ascending order of temperature. If the viscosity value of the rotating propeller at a certain measurement temperature point is higher than that at the previous measurement temperature point, a fluctuation peak is identified on the curve corresponding to that temperature point, and this measurement temperature point is designated as the temperature location of the fluctuation peak. After identifying the fluctuation peak, the difference in rotating propeller viscosity values ​​between the fluctuation peak temperature point and the previous temperature point is further calculated, and the fluctuation peak type is classified according to a preset difference threshold, with the optimal type selected. The threshold is 5. When the difference is less than 5, it is recorded as a slight fluctuation peak. When the difference is greater than or equal to 5, it is recorded as an oscillating fluctuation peak. Then, the number of slight fluctuation peaks and oscillating fluctuation peaks are counted, and the quality classification result of emulsified asphalt is output accordingly. It is preferably divided into three levels: A, B and C. Among them, the viscosity of level A is gradually decreasing with the increase of temperature and the curve is smooth or only one slight fluctuation peak appears. Level B is corresponding to only one oscillating fluctuation peak, only two slight fluctuation peaks, or one oscillating fluctuation peak and one slight fluctuation peak. Level C is corresponding to two or more oscillating fluctuation peaks, three or more slight fluctuation peaks, or one oscillating fluctuation peak and two slight fluctuation peaks.For example, in a preferred embodiment, if the test results of the sample at 20℃ to 70℃ show a continuous decrease as the temperature rises and there is no rebound from one temperature point to the previous one, then the curve does not produce a fluctuation peak and can be directly judged as Grade A based on the smooth and gradual decrease of the curve. In another embodiment, if the curve rebounds at a certain temperature point and the rebound amplitude reaches or exceeds the threshold 5, then that point constitutes an oscillating fluctuation peak. Combining the number of oscillating fluctuation peaks and slight fluctuation peaks throughout the entire range, it can fall into the judgment range of Grade B or Grade C. Through the above preferred embodiments, it is possible to distinguish between the smooth decrease and abnormal fluctuation of emulsified asphalt viscosity changes within the same temperature range, and to solidify the abnormal fluctuations into grading rules in the form of fluctuation peak type and quantity. This enables the visualization, quantification, and grading evaluation of the quality stability of emulsified asphalt, and provides a basis for product quality control and use under different temperature conditions.

[0024] The technical solution of this invention accurately identifies and classifies fluctuation peaks in viscosity-temperature curves, classifies fluctuation peaks into slight fluctuation peaks or oscillating fluctuation peaks based on preset difference thresholds, and automatically outputs quantitative grading results according to the type and number of fluctuation peaks. This solves the technical problems of existing emulsified asphalt quality assessment methods being unable to evaluate the quality stability of emulsified asphalt as it changes with temperature, and insufficient detection of temperature-dependent unstable behavior and vague grading standards due to reliance on static single parameters or subjective experience judgments. This achieves more objective, automated and high-precision quality monitoring.

[0025] Furthermore, based on a preset difference threshold, fluctuation peak types are categorized, including: If the difference between the rotating propeller viscosity value of the fluctuation peak and the rotating propeller viscosity value at the previous temperature is less than 5, it is recorded as a slight fluctuation peak. If the difference between the viscosity value of the rotating propeller at the fluctuation peak and the viscosity value of the rotating propeller at the previous temperature is greater than or equal to 5, it is recorded as an oscillating fluctuation peak.

[0026] As a preferred embodiment of the above, after completing the multi-temperature-point propeller viscosity test and constructing the viscosity-temperature curve, the fluctuation peaks appearing in the curve are further classified to transform the degree of abnormal rebound in viscosity during temperature change into a repeatable and quantifiable evaluation criterion. Specifically, it is preferable to compare the viscosity values ​​point by point in ascending order of the measured temperature. When the propeller viscosity value at a certain measured temperature point is higher than that at the previous measured temperature point, the measured temperature point is identified as the temperature point where the fluctuation peak is located, and the difference of the fluctuation peak is obtained based on this. The difference is preferably the difference between the propeller viscosity value at the temperature point corresponding to the fluctuation peak and the propeller viscosity value at the previous temperature point. A preset difference threshold is introduced to classify the fluctuation peaks, so that the same rebound phenomenon can be distinguished into different degrees of severity, thereby avoiding the rough evaluation or susceptibility to random fluctuations caused by simply relying on whether a fluctuation peak appears. Preferably, the difference threshold is set to 5. When the difference is less than 5, the difference is considered to be 5. When the difference is 5, the fluctuation peak is recorded as a slight fluctuation peak to characterize a situation where the viscosity recovery is small and the overall fluctuation is mild. When the difference is greater than or equal to 5, the fluctuation peak is recorded as an oscillating fluctuation peak to characterize a situation where the viscosity recovery is large and the fluctuation anomaly is more obvious. This provides a unified standard for subsequent quality grading based on the type and number of fluctuation peaks. For example, in the viscosity-temperature curve of a certain test sample, if the viscosity value of the rotating paddle at 40℃ only shows a slight recovery compared to 35℃ and the recovery amplitude does not reach 5, then the recovery point is classified as a slight fluctuation peak. Similarly, in the curve of another sample, if the viscosity value of the rotating paddle at 45℃ shows a large recovery compared to 40℃ and the recovery amplitude reaches or exceeds 5, then the recovery point is classified as an oscillating fluctuation peak. Through the above-mentioned preferred threshold classification method, the recovery fluctuation can be further expressed in layers under the same test procedure and data source, making the evaluation results more stable and comparable, and enhancing the ability to identify differences in the quality stability of emulsified asphalt.

[0027] Furthermore, such as Figure 2 , Figure 3 and Figure 4 As shown, the quality grading results of emulsified asphalt include: Grade A is characterized by a gradually decreasing viscosity-temperature curve that is smooth or has only one slight fluctuation peak. Grade B is characterized by the presence of only one oscillating peak, or only two slight oscillating peaks, or one oscillating peak and one slight oscillating peak. Grade C is characterized by the presence of two or more oscillating peaks, three or more slight oscillating peaks, or one oscillating peak and two slight oscillating peaks.

[0028] As a preferred embodiment of the above, the type and number of fluctuation peaks are further solidified into directly executable quality grading rules to achieve a unified standard for judging the quality stability of emulsified asphalt. Specifically, during grading, it is preferable to compare the viscosity values ​​of the rotating paddle at each measurement temperature point in the range of 20°C to 70°C in order of increasing temperature. First, it is confirmed whether the overall curve shows a gradually decreasing and smooth trend. If no fluctuation peak appears or only one slight fluctuation peak appears under this trend, the quality stability of the emulsified asphalt is judged to be good and grade A is output. If the curve has fluctuation peaks, then after completing the comparison of slight fluctuation peaks and oscillation peaks... After classifying and statistically analyzing the peaks, the preferred output grade is B or C according to the following criteria: A grade B is defined as the presence of only one oscillating peak, two slight fluctuation peaks, or a combination of one oscillating peak and one slight fluctuation peak, indicating generally stable quality but not yet reaching a level of significant abnormal fluctuation. A grade C is defined as the presence of two or more oscillating peaks, three or more slight fluctuation peaks, or a combination of one oscillating peak and two slight fluctuation peaks, indicating poor quality stability and more frequent or severe abnormal fluctuations in viscosity with temperature changes. The emulsified asphalt... The abnormal fluctuations in viscosity during temperature changes are expressed in layers by the number and type of fluctuation peaks. Furthermore, the aforementioned grading criteria enable repeatable, comparable, and quantifiable quality stability grading, thus differentiating it from existing technologies that rely solely on viscosity at a single temperature point or room-temperature storage stability methods, which struggle to reflect stability differences at different temperatures. For example, in a preferred embodiment, if the sample viscosity gradually decreases with increasing temperature and the curve is smooth, or if only a small rebound occurs at a certain temperature point and this rebound is classified as a slight fluctuation peak, then Grade A can be directly output. In another embodiment… For example, if the curve shows a single rebound at a certain temperature point and the rebound amplitude reaches or exceeds the threshold and is classified as an oscillating peak, it falls into the case of only one oscillating peak and is output as Grade B. In a further embodiment, if the curve shows multiple large rebounds at different temperature points and forms two or more oscillating peaks, it meets the Grade C criterion and is output as Grade C. Through the above-mentioned preferred grading method, the differences in temperature sensitivity stability of different emulsified asphalt samples in the range of 20℃ to 70℃ can be presented intuitively in the form of grades, providing a consistent evaluation basis for product quality control and engineering applications.

[0029] Furthermore, the selected temperature range is 20℃ to 70℃, and multiple measurement temperature points are evenly distributed at 5℃ intervals.

[0030] As a preferred embodiment of the above embodiments, in order to ensure that the viscosity-temperature curve can fully characterize the viscosity change pattern and quality stability differences of emulsified asphalt during common engineering environments and construction temperature changes, the selected test temperature range is preferably set to 20℃ to 70℃. This range covers the representative temperature range that emulsified asphalt may experience during storage, transportation, spraying, and mixing, and can capture the influence of changes in the dispersion stability of the emulsion system on viscosity during the heating process while ensuring the operability of the test. Within this temperature range, multiple measurement temperatures... The measurement points are preferably evenly distributed at 5°C intervals to form a continuous, balanced, and comparable data sequence. Specifically, these temperature points can include 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, and 70°C. Compared to obtaining viscosity indices at only a single temperature point, setting up a temperature range and equally spaced measurement points allows for a stable construction of a viscosity curve that varies with temperature. This clearly shows smooth decreases and abnormal rebounds in the curve's shape. This provides a consistent data foundation and judgment standard for subsequent fluctuation peak identification, difference threshold classification, and quality grading, avoiding problems such as fluctuations being missed due to sparse measuring points or incomparable differences between adjacent points due to uneven distribution of measuring points. Simultaneously, the fixed 5℃ interval facilitates maintaining a uniform standard during test repetition, comparison of different samples, and engineering application verification, improving the repeatability and comparability of evaluation results. For example, in the testing of a certain emulsified asphalt sample, if the viscosity data obtained at 5℃ intervals from 20℃ to 70℃ shows a continuous decrease with increasing temperature and the differences between adjacent measuring points are not significant... If no rebound occurs, it can be visually represented as a smooth downward trend on the curve. For example, another emulsified asphalt sample showed a rebound phenomenon where the viscosity at a certain measuring point was higher than that at the previous measuring point when it was around 40℃ to 50℃. Since the measuring points were evenly distributed at 5℃, this rebound could be stably captured and located at the corresponding temperature point. This provides a direct basis for identifying it as a fluctuation peak and further classifying and grading it based on the difference between adjacent points. By setting the above-mentioned optimized temperature range and measuring point interval, the emulsified asphalt quality grading technology scheme based on viscosity-temperature curve can be more fully supported and realized.

[0031] Furthermore, after each measurement temperature point reaches the test temperature, the test program is started and enters operation. Within 2 to 10 minutes after the start of operation, the viscosity value of the rotating paddle is read and recorded from the display, and the viscosity value of the rotating paddle is recorded with an accuracy of 0.1 mPa·s.

[0032] As a preferred embodiment, to ensure good comparability and repeatability of the rotary paddle viscosity values ​​obtained at each measurement temperature point set at 5°C intervals from 20°C to 70°C, thereby making the subsequent viscosity-temperature curve morphology and fluctuation peak identification, classification, and grading results more stable and reliable, when measuring the rotary paddle viscosity at each measurement temperature point, it is preferable to start the test program after the sample reaches the corresponding test temperature, and limit the reading time to within 2 to 10 minutes after the start of the test to read and record the rotary paddle viscosity value at that temperature point from the display, with the recording accuracy to 0.1 mPa·s. The prerequisite of starting the test program only after reaching the test temperature avoids reading deviations caused by rapid viscosity drift over time before the sample has fully reached the target temperature. The preferred reading window of 2 to 10 minutes provides the system with a certain degree of stability and homogenization after the start of the test, while avoiding further changes in the system state due to excessively long running time, thus preventing additional fluctuations. This allows the viscosity data at each temperature point to better reflect the effect of temperature on the emulsified asphalt composition. The recording accuracy is limited to 0.1 mPa·s, which provides sufficient resolution for calculating the difference between adjacent temperature points and threshold classification, thus reducing misjudgments of peak amplitude caused by excessively coarse recording. For example, in a preferred embodiment, when the sample is heated to 40°C and stabilized before operation, if the viscosity reads at approximately 3 minutes after operation is 31.2 mPa·s, while the viscosity reads at approximately 4 minutes after operation at 45°C is 36.0 mPa·s, a clear difference in rebound is formed between the two adjacent temperature points, which can be used to determine and classify fluctuation peaks. In another embodiment, if there is a significant difference between the reading immediately after operation starts at a certain temperature point and the reading approximately 5 minutes after operation, by limiting the reading to 2 to 10 minutes and unifying the recording accuracy, the data acquisition rules for each temperature point can be made consistent, thereby reducing false fluctuations in the curve caused by inconsistent reading timing, and ultimately better supporting and realizing the emulsified asphalt quality grading technology based on viscosity-temperature curves.

[0033] Furthermore, after sampling, the emulsified asphalt was placed in a water bath at a temperature of ±3℃ for insulation.

[0034] As a preferred embodiment of the above embodiments, to ensure that the data obtained from the multi-temperature-point rotary paddle viscosity test can truly reflect the influence of temperature changes on the state of the emulsified asphalt dispersion system, and to reduce the impact of false fluctuations in the curve caused by uneven sample temperature on the identification and classification of fluctuation peaks, after the emulsified asphalt sampling is completed, it is preferable to first place the sample in a water bath environment corresponding to the target test temperature for constant temperature insulation treatment, and the allowable deviation of the water bath temperature relative to the test temperature is controlled within ±3℃; in specific implementation, the water bath setting temperature of the sample to be tested can be adjusted sequentially between each measurement temperature point during the test process, so that the sample is in the same thermal state as the current measurement temperature point before entering the rotary paddle viscometer for measurement, thereby reducing the reading drift caused by factors such as internal temperature difference of the sample and lag in heat exchange between the surface and the interior, and avoiding the abnormal viscosity rebound caused by misjudging the thermal equilibrium process as quality instability; the water bath insulation after sampling and the temperature deviation limit are implemented. Using ±3℃ as a uniform condition before testing ensures the comparability of viscosity data between different temperature points. This allows the subsequently constructed viscosity-temperature curve to more stably present the true form of smooth decrease or abnormal fluctuation, providing a reliable data basis for the identification of fluctuation peaks, the classification of slight fluctuation peaks and oscillating fluctuation peaks based on the difference threshold, and the final quality classification. For example, in a preferred embodiment, when planning to perform a rotary paddle viscosity measurement at 40℃, the sample is first placed in a water bath set at 40℃ with fluctuations allowed within ±3℃ for a period of time. After the sample temperature tends to be uniform, the viscosity is then read. Compared to the case of direct measurement without water bath insulation, this treatment can significantly reduce the phenomenon of instantaneous high or low viscosity caused by the sample still being heated or cooled, thereby reducing local rebounds in the curve caused by non-material stability reasons and improving the consistency and repeatability of fluctuation peak identification and classification results.

[0035] Furthermore, before constructing the viscosity-temperature curve, the viscosity values ​​of the rotating propeller corresponding to each measurement temperature point are smoothed. The smoothing process includes using the moving average method or curve fitting method to eliminate the influence of test noise on the identification of fluctuation peaks.

[0036] As a preferred embodiment of the above embodiments, in order to further improve the stability of the fluctuation peak identification based on the viscosity-temperature curve and avoid misjudging abnormal fluctuations caused by instrument reading jitter, accidental operational errors, or environmental disturbances as unstable emulsified asphalt quality, before collecting the rotary paddle viscosity values ​​at each measurement temperature point from 20℃ to 70℃ and preparing to construct the viscosity-temperature curve, it is preferable to first smooth the rotary paddle viscosity values ​​corresponding to each measurement temperature point. This is to reduce the interference of high-frequency noise on the fluctuation peak criterion that the current temperature viscosity value is greater than the previous temperature viscosity value without changing the overall trend of viscosity change with temperature. Specifically, the smoothing process can preferably adopt the moving average method or the curve fitting method. When using the moving average method, the viscosity value of each measurement temperature point can be averaged with the viscosity values ​​of its adjacent temperature points to obtain a more stable viscosity sequence, thereby making the curve shape more continuous and suppressing the small repeated fluctuations between adjacent points. When using the curve fitting method, the viscosity data of each temperature point can be fitted and the fitted smooth curve can be used as the viscosity-temperature curve, thereby reducing the influence of local discrete points on the fluctuation peak identification and peak amplitude calculation. The identification of fluctuation peaks relies on the comparison between adjacent temperature points. If the reading at a certain temperature point is momentarily higher due to noise, a rebound that should not have occurred may be identified as a fluctuation peak, thus affecting the difference threshold classification and the final grading result. Therefore, by introducing the above-mentioned smoothing process before curve construction, the identification of fluctuation peaks can be made closer to the true viscosity response of the material with temperature change rather than test noise. For example, in a preferred embodiment, if the sample viscosity generally decreases with temperature, but a small rebound occurs at a certain temperature point and the rebound is analyzed to be caused by reading jitter, then after processing with the moving average method or curve fitting method, the small rebound is weakened or eliminated, and the curve is closer to a smooth decrease, thereby avoiding misclassification as a slight fluctuation peak. In another embodiment, if the sample has a real and obvious rebound fluctuation in a certain temperature range, the smoothing process will still retain the main trend of the rebound, so that it can still be identified as a fluctuation peak and continue to be used for subsequent difference threshold classification and quality grading. This improves the robustness of the evaluation method to noise and the consistency and comparability of the grading results while ensuring full disclosure and feasibility.

[0037] Furthermore, when the viscosity-temperature curve gradually decreases with increasing temperature and the overall change is smooth without any fluctuation peaks, the quality grading result of the emulsified asphalt is directly determined to be Grade A.

[0038] As a preferred embodiment of the above, after completing the multi-temperature-point rotary paddle viscosity test, obtaining the rotary paddle viscosity values ​​corresponding to each measurement temperature point, and constructing the viscosity-temperature curve, in order to make the quality grading process more in line with the evaluation logic and to avoid unnecessary peak statistical calculations on obviously stable samples, it is preferable to set a direct judgment rule for no fluctuation peaks. That is, firstly, the overall trend of the viscosity-temperature curve is checked: observe the viscosity change relationship of each adjacent measurement temperature point in the order of temperature from low to high. When the curve shows a general trend of gradually decreasing with increasing temperature and the curve changes smoothly as a whole, and there is no rebound situation in the entire temperature range where the rotary paddle viscosity value at the current temperature is greater than the rotary paddle viscosity value at the previous temperature, it can be determined that the curve has not identified any fluctuation peaks. Under this condition, it is preferable not to enter the branch steps of fluctuation peak type classification and quantity statistics, but to directly output the emulsified asphalt quality grading result as Grade A, so as to reflect that the viscosity response of the sample is stable during the heating process and there is no viscosity rebound fluctuation reflecting abnormal dispersion stability of the emulsion system. The criteria for Grade A, characterized by a gradually decreasing and smooth change in the curve, are further streamlined into an execution rule that first determines the absence of peaks and then directly assigns a grade. This gives the evaluation method a clear priority and simplified path when dealing with emulsified asphalt with good stability, ensuring consistency in judgment and reducing the uncertainty in grading caused by statistical analysis of empty sets or over-interpretation of noise perturbations. For example, in a preferred embodiment, the viscosity value of the rotating paddle at each measurement temperature point from 20℃ to 70℃ decreases point by point as the temperature increases. If no viscosity value at any temperature point is higher than that at the previous temperature point, the viscosity-temperature curve shows a continuous and smooth decrease without identifying any fluctuation peaks. At this point, Grade A can be directly determined and output. Conversely, if another sample shows a rebound in viscosity value at a certain temperature point, even if the viscosity value decreases overall in other intervals, it should still enter the fluctuation peak identification and subsequent classification and statistical process to determine whether it falls into Grade B or Grade C. Thus, the above-mentioned preferred rule achieves a closed-loop grading system that quickly clarifies stable samples and further subdivides fluctuating samples.

[0039] Example 2; Based on the same inventive concept as the viscosity-temperature curve-based emulsified asphalt quality grading method described in the foregoing embodiments, this invention also provides an emulsified asphalt quality grading system based on a viscosity-temperature curve, the system comprising: The viscosity measurement module allows setting multiple measurement temperature points within a selected temperature range and using a rotary paddle viscometer to measure the rotary paddle viscosity value of emulsified asphalt at each measurement temperature point. The curve construction module constructs a viscosity-temperature curve based on the correspondence between the viscosity value of the rotating propeller and the measurement temperature point; The peak identification module identifies all fluctuation peaks on the viscosity-temperature curve and determines the temperature position corresponding to each fluctuation peak. A fluctuation peak is defined as the current temperature at which the viscosity value of the rotating propeller is greater than the previous temperature. The difference calculation module calculates the difference in the viscosity of the rotating propeller between adjacent temperature points of the fluctuation peak, and classifies the fluctuation peak type according to the preset difference threshold. The fluctuation peak type includes slight fluctuation peak and oscillating fluctuation peak. The quality grading module outputs the quality grading results of emulsified asphalt based on the type and number of fluctuation peaks.

[0040] The adjustment system described above in this invention can effectively realize a method for quality grading of emulsified asphalt based on viscosity-temperature curves, and the technical effects it can achieve are as described in the above embodiments, and will not be repeated here.

[0041] Furthermore, the difference calculation module includes: The slight fluctuation identification unit records a slight fluctuation peak if the difference between the rotating propeller viscosity value of the fluctuation peak and the rotating propeller viscosity value at the previous temperature is less than 5. The oscillation identification unit records an oscillation peak if the difference between the viscosity value of the rotating propeller at the oscillation peak and the viscosity value of the rotating propeller at the previous temperature is greater than or equal to 5.

[0042] Similarly, the above-mentioned optimization schemes for the system can also achieve the optimization effects corresponding to the methods in Embodiment 1, which will not be repeated here.

[0043] Example 3; Based on the same inventive concept as the viscosity-temperature curve-based emulsified asphalt quality grading method in the foregoing embodiments, this invention also provides an embodiment in which a certain SBS modified emulsified asphalt sample (PCR) is used, and a rotary paddle viscosity test is performed according to the aforementioned viscosity-temperature curve-based emulsified asphalt quality grading method. The emulsified asphalt rotary paddle viscosity test results are shown in the table below, and the viscosity-temperature curve is plotted as follows. Figure 5 As shown: Table 1. Viscosity test results of SBS modified emulsified asphalt samples using a rotary paddle. From Table 1 and Figure 5 As can be seen, the viscosity-temperature curve of the emulsified asphalt is smooth, without slight fluctuation peaks or oscillating fluctuation peaks. As the temperature rises, the viscosity gradually decreases, and the curve is smooth, indicating that the emulsified asphalt has good quality stability. The quality stability evaluation of the emulsified asphalt is Grade A.

[0044] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A method for quality grading of emulsified asphalt based on viscosity-temperature curves, characterized in that, The method includes: Multiple measurement temperature points are set within a selected temperature range, and the rotary paddle viscometer is used to determine the rotary paddle viscosity value of the emulsified asphalt at each of the measurement temperature points. A viscosity-temperature curve is constructed based on the correspondence between the viscosity value of the rotating propeller and the measurement temperature point; Identify all fluctuation peaks on the viscosity-temperature curve and determine the temperature position corresponding to each fluctuation peak. The fluctuation peak is defined as the viscosity value of the rotating propeller at the current temperature being greater than the viscosity value of the rotating propeller at the previous temperature. Calculate the difference in the viscosity value of the rotating paddle between adjacent temperature points of the fluctuation peak, and classify the fluctuation peak type according to a preset difference threshold. The fluctuation peak type includes slight fluctuation peak and oscillating fluctuation peak. Based on the type and number of fluctuation peaks, the quality grading results of emulsified asphalt are output.

2. The method for quality grading of emulsified asphalt based on viscosity-temperature curves according to claim 1, characterized in that, Fluctuation peak types are classified according to preset difference thresholds, including: If the difference between the viscosity value of the rotating propeller at the fluctuation peak and the viscosity value of the rotating propeller at the previous temperature is less than 5, it is recorded as the slight fluctuation peak. If the difference between the viscosity value of the rotating propeller at the fluctuation peak and the viscosity value of the rotating propeller at the previous temperature is greater than or equal to 5, it is recorded as the oscillation fluctuation peak.

3. The method for quality grading of emulsified asphalt based on viscosity-temperature curves according to claim 1, characterized in that, The quality grading results of emulsified asphalt include: Grade A is characterized by a gradually decreasing viscosity-temperature curve that is smooth or has only one slight fluctuation peak. Grade B is characterized by the presence of only one of the aforementioned oscillation peaks, or only two of the aforementioned slight fluctuation peaks, or the presence of one of the aforementioned oscillation peaks and one of the aforementioned slight fluctuation peaks; Grade C is characterized by the presence of two or more of the aforementioned oscillation peaks, or three or more of the aforementioned slight fluctuation peaks, or one of the aforementioned oscillation peaks and two of the aforementioned slight fluctuation peaks.

4. The method for quality grading of emulsified asphalt based on viscosity-temperature curves according to claim 1, characterized in that, The selected temperature range is 20°C to 70°C, and the multiple measurement temperature points are evenly distributed at 5°C intervals.

5. The method for quality grading of emulsified asphalt based on viscosity-temperature curves according to claim 4, characterized in that, After the test temperature is reached at each of the measured temperature points, the test program is started and the test begins. Within 2 to 10 minutes after the test begins, the viscosity value of the rotating paddle is read from the display and recorded, and the viscosity value of the rotating paddle is recorded with an accuracy of 0.1 mPa·s.

6. The method for quality grading of emulsified asphalt based on viscosity-temperature curves according to claim 1, characterized in that, After sampling, the emulsified asphalt was placed in a water bath at a test temperature of ±3℃ for insulation.

7. The method for quality grading of emulsified asphalt based on viscosity-temperature curves according to claim 1, characterized in that, Before constructing the viscosity-temperature curve, the viscosity values ​​of the rotating paddle corresponding to each of the measured temperature points are smoothed. The smoothing process includes using a moving average method or a curve fitting method to eliminate the influence of test noise on the identification of the fluctuation peak.

8. The method for quality grading of emulsified asphalt based on viscosity-temperature curves according to claim 3, characterized in that, When the viscosity-temperature curve gradually decreases with increasing temperature and the overall change is smooth without identifying any fluctuation peaks, the quality grading result of the emulsified asphalt is directly determined to be Grade A.

9. A quality grading system for emulsified asphalt based on viscosity-temperature curves, characterized in that, The system includes: The viscosity measurement module allows setting multiple measurement temperature points within a selected temperature range and using a rotary paddle viscometer to measure the rotary paddle viscosity value of emulsified asphalt at each measurement temperature point. The curve construction module constructs a viscosity-temperature curve based on the correspondence between the viscosity value of the rotating propeller and the measurement temperature point; The peak identification module identifies all fluctuation peaks on the viscosity-temperature curve and determines the temperature position corresponding to each fluctuation peak. A fluctuation peak is defined as the current temperature at which the viscosity value of the rotating propeller is greater than the previous temperature. The difference calculation module calculates the difference in the viscosity of the rotating propeller between adjacent temperature points of the fluctuation peak, and classifies the fluctuation peak type according to the preset difference threshold. The fluctuation peak type includes slight fluctuation peak and oscillating fluctuation peak. The quality grading module outputs the quality grading results of emulsified asphalt based on the type and number of fluctuation peaks.

10. The emulsified asphalt quality grading system based on viscosity-temperature curves according to claim 9, characterized in that, The difference calculation module includes: The slight fluctuation identification unit records a slight fluctuation peak if the difference between the rotating propeller viscosity value of the fluctuation peak and the rotating propeller viscosity value at the previous temperature is less than 5. The oscillation identification unit records an oscillation peak if the difference between the viscosity value of the rotating propeller at the oscillation peak and the viscosity value of the rotating propeller at the previous temperature is greater than or equal to 5.

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