Ultrasonic triggering microcapsule asphalt pavement testing method and device

Abstract

The invention provides a test method and device for an ultrasonic triggering microcapsule asphalt pavement, and the method comprises the steps: carrying out the ultrasonic triggering tests of different frequencies and powers on each pre-test sample, and collecting the ultrasonic echo data of each pre-test sample in each ultrasonic triggering test process; extracting a plurality of trigger data from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data; identifying a triggering point of microcapsule triggering fracture in each triggering data, and determining a triggering lower limit of the microcapsule in the target asphalt pavement based on all the triggering points; performing a fatigue cycle test on each main test sample based on the trigger lower limit, and collecting dynamic modulus data of each main test sample after each round of fatigue cycle; and determining the self-healing rate of the target asphalt pavement according to all dynamic modulus data in the fatigue cycle test. By adopting the scheme of the invention, the adaptive ultrasonic parameters in the test can be set according to the ultrasonic transmission characteristics in different pavements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of asphalt repair materials, and more particularly to a test method and device for ultrasonic triggered microcapsule asphalt pavement. BACKGROUND

[0002] Ultrasonic triggered microcapsule asphalt pavement is a new technology developed in recent years in the field of pavement engineering to improve pavement durability. The core principle is to uniformly mix microcapsules containing asphalt repair agents into asphalt mixture. When the pavement produces micro-cracks under the action of driving load and temperature changes, the microcapsule wall material is broken by a specific ultrasonic signal, releasing the internal repair agent, which flows and solidifies at the crack, achieving self-healing of the pavement cracks, thereby extending the service life of the pavement and reducing maintenance costs. Since the performance of such pavement depends directly on the effective triggering efficiency and self-healing effect of the microcapsules, a special test method is needed to quantify and evaluate its key performance indicators, providing technical support for pavement construction quality control and engineering application feasibility verification.

[0003] In the prior art, fixed ultrasonic frequency and power are often used for testing. However, in actual applications, the differences in pavement conditions can affect the transmission of ultrasonic waves. The prior art does not consider the differences in ultrasonic wave transmission in different pavements, which can lead to problems such as damage to the pavement matrix due to excessively high ultrasonic parameters or failure to trigger microcapsules due to excessively low parameters, resulting in distorted test data and an inability to objectively reflect the self-healing ability of the pavement under actual stress conditions. Therefore, how to set appropriate ultrasonic parameters in tests based on the transmission characteristics of ultrasonic waves in different pavements has become a difficult problem in the industry. SUMMARY

[0004] The present application provides a test method and device for ultrasonic triggered microcapsule asphalt pavement, which can set appropriate ultrasonic parameters in tests based on the transmission characteristics of ultrasonic waves in different pavements.

[0005] In a first aspect, the present application provides a test method for ultrasonic triggered microcapsule asphalt pavement. A plurality of cylindrical samples are collected from a target asphalt pavement. The method includes: dividing all the cylindrical samples into pre-test samples and main test samples; conducting ultrasonic triggering tests of different frequencies and powers on each pre-test sample, collecting ultrasonic echo data of each pre-test sample during each ultrasonic triggering test, and extracting a plurality of triggering data from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data; identifying the triggering points of microcapsule triggering rupture in each triggering data, and determining the triggering lower limit of the microcapsules in the target asphalt pavement based on all the triggering points; performing a fatigue cycle test on each main test sample based on the trigger lower limit, and collecting dynamic modulus data of each main test sample after each fatigue cycle; determining a self-healing rate of the target asphalt pavement according to all the dynamic modulus data in the fatigue cycle test, and outputting a test report of the target asphalt pavement based on the self-healing rate.

[0006] In some embodiments, the ultrasonic trigger test of different frequencies and powers on each pre-test sample specifically comprises: setting multiple groups of test parameters in order of increasing frequency and power; selecting one pre-test sample as a selected pre-test sample, and fixing the selected pre-test sample on the test device; emitting ultrasonic waves to the selected pre-test sample according to each group of test parameters in turn, and completing the ultrasonic trigger test of the selected pre-test sample; continuing to complete the ultrasonic trigger test of the pre-test sample.

[0007] In some embodiments, the extracting of multiple trigger data from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data specifically comprises: determining an energy change curve of each ultrasonic echo in each ultrasonic echo data; extracting a local fluctuation sequence of each energy change curve; determining a trend characteristic of the corresponding ultrasonic echo of each energy change curve according to the local fluctuation sequence of each energy change curve; comparing all the trend characteristics with a preset trigger trend threshold, and then extracting multiple trigger data from all the ultrasonic echo data.

[0008] In some embodiments, the identifying of the trigger point of the microcapsule trigger rupture in each trigger data specifically comprises: selecting one trigger data as a selected trigger data, and determining a time sequence correlation degree sequence of the selected trigger data; dividing the selected trigger data into pre-trigger data and post-trigger data according to the time sequence correlation degree sequence; fitting the pre-trigger data and the post-trigger data respectively, and then obtaining the trigger point of the microcapsule trigger rupture in the selected trigger data; continuing to determine the trigger point of the microcapsule trigger rupture in the remaining trigger data.

[0009] In some embodiments, the determining of the trigger lower limit of the microcapsule in the target asphalt pavement based on all the trigger points specifically comprises: determining an equivalent trigger power of each trigger point; converting all the trigger points into a power-frequency coordinate system according to the equivalent trigger power. A trigger lower limit of the microcapsule in the target asphalt pavement is identified in the power-frequency coordinate system.

[0010] In some embodiments, the fatigue cycle test on each main test sample based on the trigger lower limit specifically comprises: selecting one main test sample as a selected main test sample, and fixing the selected main test sample in a fatigue test device; applying a preset pressure to the selected main test sample for fatigue treatment; ultrasonic scanning the selected main test sample after the fatigue treatment according to the trigger lower limit; reapplying the preset pressure to the selected main test sample after the ultrasonic scanning for fatigue treatment, so as to complete the fatigue cycle test on the selected main test sample; continuing to complete the fatigue cycle test on the remaining main test samples.

[0011] In some embodiments, determining the self-healing rate of the target asphalt pavement according to all the dynamic modulus data in the fatigue cycle test specifically comprises: determining a dynamic modulus drop ratio according to all the dynamic modulus data; taking the dynamic modulus drop ratio as the self-healing rate of the target asphalt pavement.

[0012] In some embodiments, the ultrasonic echo data of each pre-test sample in each ultrasonic trigger test is collected by an ultrasonic probe.

[0013] In some embodiments, the dynamic modulus data of each main test sample after each round of fatigue cycle is collected by a static load compression elastic modulus test.

[0014] In a second aspect, the present application provides a testing device for ultrasonic trigger microcapsule asphalt pavement, comprising: a pretreatment module for dividing all the cylindrical samples into pre-test samples and main test samples; a processing module for performing ultrasonic trigger tests on each pre-test sample at different frequencies and powers, collecting ultrasonic echo data of each pre-test sample in each ultrasonic trigger test, and extracting a plurality of trigger data from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data; The processing module is further configured to identify a trigger point of microcapsule trigger rupture in each trigger data, determine a trigger lower limit of the microcapsule in the target asphalt pavement based on all the trigger points; a test module for performing a fatigue cycle test on each main test sample based on the trigger lower limit, and collecting dynamic modulus data of each main test sample after each round of fatigue cycle; The test module is also used for determining a self-healing rate of the target asphalt pavement according to all dynamic modulus data in the fatigue cycle test, and outputting a test report of the target asphalt pavement based on the self-healing rate.

[0015] The technical scheme provided by the embodiments disclosed in the present application has the following beneficial effects: In the test method and device for the ultrasonic triggered microcapsule asphalt pavement provided by the present application, first, all the cylindrical samples are divided into pre-test samples and main test samples; the ultrasonic triggering test of different frequencies and powers is performed on each pre-test sample, and the ultrasonic echo data of each pre-test sample in each ultrasonic triggering test process is collected, a plurality of triggering data is extracted from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data; the triggering point of the microcapsule triggering rupture in each triggering data is identified, and the triggering lower limit of the microcapsule in the target asphalt pavement is determined based on all the triggering points; the fatigue cycle test is performed on each main test sample based on the triggering lower limit, and the dynamic modulus data of each main test sample after each cycle of fatigue cycle is collected; the self-healing rate of the target asphalt pavement is determined according to all the dynamic modulus data in the fatigue cycle test, and then a test report of the target asphalt pavement is output based on the self-healing rate.

[0016] As can be seen, by dividing the cylindrical samples into pre-test samples and main test samples, performing the ultrasonic triggering test of multiple frequencies and multiple powers on the pre-test samples and collecting the ultrasonic echo data, extracting the triggering data in combination with the data trend characteristics, identifying the triggering point of the microcapsule triggering rupture to determine the triggering lower limit, the ultrasonic wave transmission characteristics of different pavements can be accurately adapted, the pavement matrix damage or microcapsule triggering invalid problem caused by the fixed ultrasonic parameters in the prior art can be avoided, and the test data authenticity is ensured, and then the fatigue cycle test is performed on the main test samples based on the triggering lower limit, the self-healing rate is determined by collecting the dynamic modulus data after each cycle, and the test report is output, which can objectively reflect the self-healing capacity of the pavement under the actual stress working condition. In summary, by using the scheme of the present application, the ultrasonic wave parameters in the test can be set according to the ultrasonic wave transmission characteristics in different pavements. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is an example flowchart of the test method for the ultrasonic triggered microcapsule asphalt pavement according to some embodiments of the present application; Figure 2 is an example flowchart of the ultrasonic triggering test according to some embodiments of the present application; Figure 3 is an example flowchart of determining the triggering point according to some embodiments of the present application; Figure 4 is a structural schematic diagram of the test device for the ultrasonic triggered microcapsule asphalt pavement according to some embodiments of the present application; Figure 5 Figure 1 is a structural schematic diagram of a computer device for implementing a test method of an ultrasonic triggered microcapsule asphalt pavement according to some embodiments of the present application. DETAILED DESCRIPTION

[0018] In order to better understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in combination with the drawings of the specification and specific embodiments.

[0019] Reference Figure 1 Figure 2 is an exemplary flowchart of a test method of an ultrasonic triggered microcapsule asphalt pavement according to some embodiments of the present application, which mainly includes the following steps: In step 101, all the cylindrical samples are divided into pre-test samples and main test samples.

[0020] In some embodiments, before all the cylindrical samples are divided into pre-test samples and main test samples, it further includes: collecting a plurality of cylindrical samples in advance from the target asphalt pavement, as a preferred embodiment, the plurality of cylindrical samples collected in advance from the target asphalt pavement can be realized in the following manner, that is: first, a plurality of sampling points are set on the target asphalt pavement, the sampling points can be set according to actual needs, for example, a representative section of the target asphalt pavement without obvious macroscopic cracks, potholes and other diseases can be selected, and 3 sampling points are selected per 100m section to ensure that the sampling points cover different stress areas such as road wheel track band and road shoulder, secondly, cylindrical samples are collected by drilling method at each sampling point, and all the collected cylindrical samples are used as cylindrical samples of the target asphalt pavement, for example, a road core drilling machine with a 100mm diameter diamond drill bit can be used to slowly drill at a speed of 50-100r / min at the sampling point to a depth of 50mm to take out the cylindrical sample, wherein water cooling is performed during the drilling process.

[0021] When specifically implemented, all the cylindrical samples can be divided into pre-test samples and main test samples in the following manner, that is, all the cylindrical samples can be divided into two groups on average, one group as pre-test samples and the other group as main test samples.

[0022] It should be noted that the pre-test samples in the present application are samples used for ultrasonic triggering test, and the main test samples refer to samples used for fatigue cycle test.

[0023] In step 102, ultrasonic triggering test of different frequencies and powers is performed on each pre-test sample, and ultrasonic echo data of each pre-test sample during each ultrasonic triggering test is collected, and a plurality of triggering data are extracted from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data.

[0024] In some embodiments, with reference to Figure 2 The figure is an exemplary flow chart of the ultrasonic triggering test according to some embodiments of the present application, and the following steps can be used to implement the ultrasonic triggering test of different frequencies and powers for each pre-test sample in the present application: In step 1021, multiple sets of test parameters are set in order of increasing frequency and power; In step 1022, a pre-test sample is selected as a selected pre-test sample, and the selected pre-test sample is fixed on the test device; In step 1023, ultrasonic waves are emitted to the selected pre-test sample according to each set of test parameters in turn, and the ultrasonic triggering test of the selected pre-test sample is completed; In step 1024, the ultrasonic triggering test of the pre-test sample is continued.

[0025] In specific implementation, multiple sets of test parameters can be set in order of increasing frequency and power in the following manner, that is, first, the frequency range and power range of the ultrasonic waves in the ultrasonic triggering test are set, and multiple sets of test parameters are uniformly divided in the frequency range and power range, for example, the frequency range of the ultrasonic waves can be set as 20 kHz-10 MHz and the power range can be set as 0.1 W / square centimeter-1 W / square centimeter according to specific requirements, and 5 frequency values are uniformly divided in the frequency range, that is, 20 kHz, 25 15 kHz, 50 10 kHz, 75 5 kHz and 10 MHz, and then the same number of power values are uniformly divided in the power range, that is, 0.1 W / square centimeter, 0.325 W / square centimeter, 0.55 W / square centimeter, 0.775 W / square centimeter and 1.0 W / square centimeter, and then matched in order from small to large, that is, each power value is matched with each frequency value to form a set of test parameters, and 25 sets of test parameters are obtained, and in other embodiments, other manners can be used to divide other multiple sets of test parameters, which are not limited here.

[0026] It should be noted that the test parameters in the present application refer to the parameter set of the frequency and power of the ultrasonic waves set to be emitted in the ultrasonic triggering test.

[0027] In a specific implementation, the fixing of the selected pre-test sample on the testing device can be achieved by the following method: first, place the selected pre-test sample in the center positioning groove of the clamping assembly in the testing device, make the lower end surface of the selected pre-test sample completely adhere to the rubber buffer pad at the bottom of the positioning groove, and align the axis with the preset emission axis of the ultrasonic probe on the testing device, then rotate the manual adjustment knobs on both sides of the clamping assembly, slowly tighten the clamping jaws until the selected pre-test sample has no radial displacement, finally, use a level to calibrate the levelness of the upper surface of the selected pre-test sample, if there is an inclination, slightly adjust the height knob of the clamping assembly, so that the distance between the upper surface of the sample and the ultrasonic probe is stably kept within the range of 1-2 mm, lock the adjustment knob after calibration, and complete the fixing of the selected pre-test sample.

[0028] In a specific implementation, the ultrasonic wave is emitted to the selected pre-test sample according to each set of test parameters, and the ultrasonic triggering test of the selected pre-test sample can be achieved by the following method: for each set of test parameters, the ultrasonic probe emits ultrasonic waves to the selected pre-test sample according to the power and frequency of each set of test parameters, the duration of emission is 30 seconds, and the interval between adjacent two sets of test parameters is 20 seconds, wherein the test parameters need to be selected in the order of frequency from small to large, and then power from small to large.

[0029] In a specific implementation, the ultrasonic echo data of each pre-test sample in each ultrasonic triggering test process can be achieved by the following method: for each emission of ultrasonic wave in each ultrasonic triggering test, ultrasonic echo is collected through the ultrasonic probe at the same time of emitting ultrasonic wave, and the set composed of all the ultrasonic echoes collected in each ultrasonic triggering test is taken as the ultrasonic echo data of each pre-test sample in each ultrasonic triggering test.

[0030] In some embodiments, the multiple triggering data are extracted from all the ultrasonic echo data based on the trend features of all the ultrasonic echo data, which can be achieved by the following steps: For each ultrasonic echo in each ultrasonic echo data, determine the energy change curve of each ultrasonic echo; Extract the local fluctuation sequence of each energy change curve; Determine the trend feature of the corresponding ultrasonic echo of each energy change curve according to the local fluctuation sequence of each energy change curve; Compare all the trend features with the preset triggering trend threshold, and then extract the multiple triggering data from all the ultrasonic echo data.

[0031] In a specific implementation, the energy variation curve of each ultrasonic echo can be determined in the following manner: for each ultrasonic echo, the ultrasonic echo is smoothed and denoised, for example, by using the sliding window integration method in the prior art, and then the smoothed and denoised curve is squared, and each squared curve is taken as the energy variation curve of the ultrasonic echo.

[0032] It should be noted that the energy variation curve in the present application is a curve describing the variation of the energy of the ultrasonic echo with time.

[0033] In a specific implementation, the local fluctuation sequence of each energy variation curve can be determined in the following manner: first, an energy variation curve is selected as a selected energy variation curve, then a sequence of increasing interval lengths is set, for each interval length in the sequence, the selected energy variation curve is divided into a plurality of non-overlapping subintervals according to the interval length, then the average value of each subinterval is calculated, and the selected energy variation curve in each subinterval is subtracted from the average value and integrated, and the difference between the maximum value and the minimum value of the integrated curve is taken as the range of each subinterval, secondly, the ratio of the range of each subinterval to the standard deviation of each subinterval is taken as the fluctuation feature of each subinterval, and the average value of all fluctuation features of the subintervals is taken as the local fluctuation feature under the corresponding interval length, finally, all local fluctuation features are arranged in ascending order of interval length, and the sequence obtained by the arrangement is taken as the local fluctuation sequence of the selected energy variation curve, and the local fluctuation sequences of the remaining energy variation curves are determined, wherein the sequence of interval lengths can be set according to the length of the energy variation curve, for example, if the length of the energy variation curve is 30s, the sequence of interval lengths can be set as a sequence increasing by powers of 2, i.e. 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048 (unit: ms), and the maximum length is not more than 1 / 10 of the total length of the curve, i.e. 3000ms.

[0034] It should be noted that the local fluctuation sequence in the present application is a sequence for describing the local fluctuation characteristics of the energy variation curve under different interval lengths, wherein each local fluctuation feature in the local fluctuation sequence corresponds to the local fluctuation characteristics of the energy variation curve under a specified interval length.

[0035] In a specific implementation, the trend feature of the ultrasonic echo corresponding to each energy change curve can be determined according to the local fluctuation sequence of each energy change curve in the following manner: first, for each energy change curve, the interval length corresponding to each local fluctuation feature in the local fluctuation sequence of each energy change curve is obtained, then, curve fitting is performed on each local fluctuation sequence, wherein the dependent variable of the curve fitting is the natural logarithm of the local fluctuation feature, and the independent variable is the natural logarithm of the interval length, the curve fitting is performed by the least square method in the prior art to obtain a curve with the highest degree of one, and the slope of each curve is obtained as the trend feature of the ultrasonic echo corresponding to each energy change curve.

[0036] It should be noted that the trend feature in the present application is a parameter value for quantifying the trend of the ultrasonic echo energy change, and the trend feature is a value between 0 and 1. The closer the trend feature is to 0.5, the more the energy change of the corresponding ultrasonic echo has no obvious trend feature (i.e., there is no capsule breaking), and the greater the difference between the trend feature and 0.5, the more the energy change of the corresponding ultrasonic echo has an obvious trend feature (i.e., there is capsule breaking leading to the change of the ultrasonic echo energy).

[0037] In a specific implementation, the comparison between all the trend features and the preset trigger trend threshold, and the extraction of the multiple trigger data from all the ultrasonic echo data can be implemented in the following manner: first, the relative error between all the trend features and the preset trigger trend threshold is calculated, and the ultrasonic echo corresponding to the trend feature with a relative error outside 10% in all the ultrasonic echo data is taken as the trigger data.

[0038] It should be noted that the trigger data in the present application refers to the data of the ultrasonic echo of the microcapsule triggered rupture in the pretest sample.

[0039] In step 103, the trigger point of the microcapsule triggered rupture in each trigger data is identified, and the trigger lower limit of the microcapsule in the target asphalt pavement is determined based on all the trigger points.

[0040] In some embodiments, with reference to Figure 3 The figure is an exemplary flowchart for determining the trigger point according to some embodiments of the present application, and the identification of the trigger point of the microcapsule triggered rupture in each trigger data in the present application can be implemented in the following steps: In step 1031, one trigger data is selected as a selected trigger data, and the time sequence correlation sequence of the selected trigger data is determined; In step 1032, the selected trigger data is divided into pre-trigger data and post-trigger data according to the time sequence correlation sequence; In step 1033, the pre-trigger data and the post-trigger data are fitted respectively, and then the trigger point of the microcapsule triggered rupture in the selected trigger data is obtained. In step 1034, the trigger point of the microcapsule trigger rupture in the remaining trigger data is determined.

[0041] In specific implementation, the time sequence correlation degree sequence of the selected trigger data can be determined in the following manner: first, a plurality of lag times are set, and the autocorrelation coefficients of the selected trigger data at each lag time are calculated, then, all the autocorrelation coefficients are arranged in ascending order of the lag time, and the sequence obtained by the arrangement is taken as the time sequence correlation degree sequence of the selected trigger data, wherein the lag time can be set according to the length of the selected trigger data, for example, when the length of the selected trigger data is 30s, the lag time can be set as 0.1s, 0.5s, 1s, 3s, 5s, 10s, 15s, 20s, 25s, and in other embodiments, the lag time can also be set as other values, which are not limited here.

[0042] It should be noted that the time sequence correlation degree sequence in the present application is a sequence for quantifying the autocorrelation degree of the trigger data at different time lags.

[0043] In specific implementation, the selected trigger data can be divided into pre-trigger data and post-trigger data according to the time sequence correlation degree sequence in the following manner: each autocorrelation coefficient in the time sequence correlation degree sequence is compared with a preset correlation degree threshold in turn, the lag time t corresponding to the first autocorrelation coefficient less than the correlation degree threshold is recorded, and the data before t time in the selected trigger data is taken as the pre-trigger data, and the data after t time in the selected trigger data is taken as the post-trigger data.

[0044] It should be noted that the pre-trigger data in the present application refers to the data of the ultrasonic echo before the microcapsule trigger rupture in the pre-test sample, and the post-trigger data refers to the data of the ultrasonic echo after the microcapsule trigger rupture in the pre-test sample.

[0045] In specific implementation, the pre-trigger data and the post-trigger data can be fitted respectively, and then the trigger point of the microcapsule trigger rupture in the selected trigger data can be obtained in the following manner: the pre-trigger data and the post-trigger data are fitted into curves respectively, and the intersection of the two curves is taken as the trigger point of the microcapsule trigger rupture in the selected trigger data, wherein the pre-trigger data and the post-trigger data can be fitted by the least square method in the prior art, and in other embodiments, other prior art can also be used for fitting, which is not limited here.

[0046] It should be noted that the trigger point in the present application refers to the data point of the ultrasonic echo when the microcapsule trigger rupture in the pre-test sample.

[0047] In some embodiments, determining the trigger lower limit of the microcapsules in the target asphalt pavement based on all the trigger points can be achieved by the following steps: determining the equivalent trigger power of each trigger point; converting all the trigger points into a power-frequency coordinate system according to the equivalent trigger power; identifying the trigger lower limit of the microcapsules in the target asphalt pavement in the power-frequency coordinate system.

[0048] In specific implementation, the equivalent trigger power of each trigger point can be determined by the following method, that is, for each trigger point, first, the test parameters of the ultrasonic trigger test corresponding to each trigger point and the trigger duration corresponding to the trigger point (i.e. the time difference between the time of the trigger point and the time of the start of the corresponding ultrasonic trigger test) are obtained, and the product of the power in the test parameters and the trigger duration is divided by the duration of the ultrasonic wave in each ultrasonic trigger test, and all the obtained values are respectively taken as the equivalent trigger power of the corresponding trigger point.

[0049] It should be noted that the equivalent trigger power in the present application refers to the normalized ultrasonic power, which is used to quantify the actual energy input intensity of the microcapsule rupture under different durations of ultrasonic waves.

[0050] In specific implementation, converting all the trigger points into a power-frequency coordinate system according to the equivalent trigger power can be achieved by the following method, that is, first, the frequency in the test parameters of the ultrasonic trigger test corresponding to each trigger point is obtained, and all the trigger points are plotted in the power-frequency coordinate system, wherein the abscissa of each trigger point is the equivalent trigger power of each trigger point, and the ordinate of each trigger point is the frequency of each trigger point.

[0051] In addition, in specific implementation, the trigger lower limit of the microcapsules in the target asphalt pavement can be identified in the power-frequency coordinate system by the following method, that is, first, the convex hull of all the trigger points is calculated in the power-frequency coordinate system, and the curves on the right and upper sides of the convex hull are removed, only the curves on the left and lower sides of the convex hull are retained, and the retained curves are taken as the trigger lower limit of the microcapsules in the target asphalt pavement, wherein the convex hull of all the trigger points can be calculated by the Gao Li-heng scanning method in the prior art, and in other embodiments, the convex hull of all the trigger points can also be calculated by other prior art, which is not limited here.

[0052] It should be noted that the trigger lower limit in the present application is a critical curve reflecting the minimum power and minimum frequency that can trigger the rupture of the microcapsules in the target asphalt pavement.

[0053] In step 104, fatigue cycle tests are performed on each master test sample based on the trigger lower limit, and dynamic modulus data of each master test sample after each fatigue cycle is collected.

[0054] In some embodiments, the fatigue cycle test on each master test sample based on the trigger lower limit can be implemented by the following steps: selecting one master test sample as a selected master test sample, and fixing the selected master test sample in a fatigue test device; applying a preset pressure to the selected master test sample for fatigue treatment; performing ultrasonic scanning on the selected master test sample after the fatigue treatment according to the trigger lower limit; applying the preset pressure to the selected master test sample after the ultrasonic scanning again for fatigue treatment, so as to complete the fatigue cycle test of the selected master test sample; continuing to complete the fatigue cycle test of the remaining master test samples.

[0055] In specific implementation, the fixing of the selected master test sample in the fatigue test device can be implemented by the following manner: first, the selected master test sample is smoothly placed into the center positioning groove of the clamping assembly in the fatigue test device, so that the lower end surface of the selected master test sample is completely attached to the rubber buffer pad at the bottom of the positioning groove, and the axis is aligned with the axis of the loading shaft in the fatigue test device, then the manual adjustment knobs on both sides of the clamping assembly are rotated, the clamping jaws are slowly tightened until there is no radial displacement of the selected master test sample, finally, the levelness of the upper surface of the selected master test sample is calibrated by using a level, if there is inclination, the height knob of the clamping assembly is finely adjusted, after calibration, the adjustment knobs are locked, and the fixing of the selected master test sample is completed.

[0056] In specific implementation, the fatigue treatment of the selected master test sample by applying the preset pressure can be implemented by the following manner: first, the preset pressure is set according to actual requirements, then the selected master test sample is loaded with the preset pressure, the frequency of loading is set to 10 Hz, and the number of loading is set to 1000 times, so as to complete the fatigue treatment of the selected master test sample, wherein the preset pressure can be set according to the actual working condition of the target asphalt pavement, for example, the average value of the weight of the vehicle passing through the target asphalt pavement in a day can be counted, and the pressure corresponding to the average value of the weight is taken as the preset pressure.

[0057] In specific implementation, the ultrasonic scanning on the selected master test sample after the fatigue treatment according to the trigger lower limit can be implemented by the following manner: first, the selected master test sample after the fatigue treatment is placed for 1 minute, then ultrasonic waves are emitted to the selected master test sample, the frequency and power of the ultrasonic waves are constantly changed according to the curve of the trigger lower limit, and the duration is 30 s, so as to complete the ultrasonic scanning on the selected master test sample.

[0058] In a specific implementation, the fatigue treatment of the selected main test sample after ultrasonic scanning can be implemented in the following manner: first, set the preset pressure according to actual requirements, then load the preset pressure on the selected main test sample after ultrasonic scanning, the loading frequency is set to 10 Hz, and the loading times is set to 1000, thereby completing the fatigue treatment of the selected main test sample, wherein the preset pressure can be set according to the actual working condition of the target asphalt pavement, for example, the average value of the weight of the vehicle passing through the target asphalt pavement in one day can be counted, and the pressure corresponding to the average value of the weight is taken as the preset pressure.

[0059] In a specific implementation, the dynamic modulus data of each main test sample after each fatigue cycle can be collected in the following manner: the elastic modulus of each main test sample after each fatigue cycle can be collected according to the process of the static compression elastic modulus test in the national standard document GB / T50081-2019 “Standard Test Methods for Mechanical Properties of Concrete”, and the collected elastic modulus is taken as the dynamic modulus data of each main test sample after each fatigue cycle.

[0060] It should be noted that the environmental temperature is kept constant at 20°C during the fatigue cycle test in the present application.

[0061] In step 105, the self-healing rate of the target asphalt pavement is determined according to all the dynamic modulus data in the fatigue cycle test, and then a test report of the target asphalt pavement is output based on the self-healing rate.

[0062] In some embodiments, the self-healing rate of the target asphalt pavement can be determined according to all the dynamic modulus data in the fatigue cycle test in the following steps: determine the dynamic modulus reduction ratio according to all the dynamic modulus data; take the dynamic modulus reduction ratio as the self-healing rate of the target asphalt pavement.

[0063] In a specific implementation, the dynamic modulus reduction ratio can be determined according to all the dynamic modulus data in the following manner: for each main test sample, calculate the difference a between the dynamic modulus data collected twice for each main test sample, then calculate the difference b between the dynamic modulus collected for the first time for each main test sample and the initial dynamic modulus of each main test sample, and take the average value of the ratio of all a and b as the dynamic modulus reduction ratio, wherein the initial dynamic modulus of each main test sample refers to the dynamic modulus of the main test sample before the fatigue cycle test, the elastic modulus of the main test sample can be collected before the fatigue cycle test according to the process of the static compression elastic modulus test in the national standard document GB / T50081-2019 “Standard Test Methods for Mechanical Properties of Concrete”, and the elastic modulus is taken as the initial dynamic modulus.

[0064] It should be noted that the dynamic modulus reduction ratio in the present application is a parameter value reflecting the degree of alleviation of the self-repairing effect of the microcapsule on the fatigue damage in each round of fatigue cycle.

[0065] It should be noted that the self-healing rate in the present application is a parameter value quantifying the strength of the self-repairing capability of the microcapsule in the asphalt pavement.

[0066] In a specific implementation, the test report of the target asphalt pavement can be output by filling the self-healing rate, the trigger lower limit and the parameters set in the ultrasonic trigger test and the fatigue cycle test of the target asphalt pavement into the report.

[0067] In addition, another aspect of the present application provides an ultrasonic trigger microcapsule asphalt pavement testing device in some embodiments, which refers to Figure 4 The figure is a structural schematic diagram of an ultrasonic trigger microcapsule asphalt pavement testing device according to some embodiments of the present application, which includes a pretreatment module 401, a processing module 402 and a test module 403, which are described as follows: The pretreatment module 401 is mainly used for dividing all the cylindrical samples into pre-test samples and main test samples in the present application; The processing module 402 is mainly used for performing ultrasonic trigger tests of different frequencies and powers on each pre-test sample, collecting ultrasonic echo data of each pre-test sample in each ultrasonic trigger test, extracting a plurality of trigger data from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data in the present application; It should be noted that the processing module 402 is also used for identifying the trigger point of the microcapsule trigger rupture in each trigger data, and determining the trigger lower limit of the microcapsule in the target asphalt pavement based on all the trigger points in the present application; The test module 403 is mainly used for performing fatigue cycle tests on each main test sample based on the trigger lower limit in the present application, and collecting dynamic modulus data of each main test sample after each round of fatigue cycle; It should be noted that the test module 403 is also used for determining the self-healing rate of the target asphalt pavement according to all the dynamic modulus data in the fatigue cycle test, and outputting the test report of the target asphalt pavement based on the self-healing rate in the present application.

[0068] In addition, the present application also provides a computer device, which includes a memory and a processor, the memory stores code, and the processor is configured to acquire the code and execute the above-mentioned ultrasonic trigger microcapsule asphalt pavement testing method.

[0069] In some embodiments, referring to Figure 5 The figure is a structural schematic diagram of a computer device for implementing the test method of the ultrasonic triggered microcapsule asphalt pavement according to some embodiments of the present application. The test method of the ultrasonic triggered microcapsule asphalt pavement in the above embodiments can be implemented by the computer device shown in the figure. The computer device 500 includes at least one processor 501, a communication bus 502, a memory 503, and at least one communication interface 504. Figure 5

[0070] The processor 501 can be a general central processing unit (CPU) or an application-specific integrated circuit (ASIC).

[0071] The communication bus 502 can be used to transmit information between the above components.

[0072] The memory 503 can be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, an optical disk storage (including a compact disk, a laser disk, an optical disk, a digital versatile disk, a Blu-ray disk, etc.), a magnetic disk or other magnetic storage device, or any other medium that can be used to carry or store desired program codes in the form of instructions or data structures and can be accessed by a computer, but not limited to this. The memory 503 can exist independently and be connected to the processor 501 through the communication bus 502. The memory 503 can also be integrated with the processor 501.

[0073] The memory 503 is used to store program codes for executing the schemes of the present application, and the processor 501 is used to control the execution. The processor 501 is used to execute the program codes stored in the memory 503. The program codes can include one or more software modules. The test method of the ultrasonic triggered microcapsule asphalt pavement in the above embodiments can be implemented by the processor 501 and one or more software modules in the program codes in the memory 503.

[0074] ​The communication interface 504, using any transceiver-like device, is used to communicate with other devices or computer systems on the network. By way of example, the communication interface 504 can be a Ethernet card, a modem, a wireless radio frequency transmitter / receiver, a Bluetooth transmitter / receiver, a cellular telephone transmitter / receiver, or the like.

[0075] In a particular implementation, as one example, the computer device can include multiple processors, each of which can be a single-CPU processor or a multi-CPU processor. A processor can refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0076] The computer device described above can be a general purpose computer device or a special purpose computer device. In a particular implementation, the computer device can be a desktop computer, a laptop computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, or an embedded device. The embodiments of the present application do not limit the type of computer device.

[0077] In addition, the present application also provides a computer readable storage medium, the computer readable storage medium stores a computer program, the computer program is executed by a processor to realize the test method of the ultrasonic triggered microcapsule asphalt pavement described above.

[0078] To sum up, the test method and device of the ultrasonic triggered microcapsule asphalt pavement disclosed in the embodiments of the present application, first, all the cylindrical samples are divided into pre-test samples and main test samples; the ultrasonic triggering test of different frequencies and powers is performed on each pre-test sample, and the ultrasonic echo data of each pre-test sample in each ultrasonic triggering test process is collected, a plurality of triggering data are extracted from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data; the triggering point of the microcapsule triggering rupture in each triggering data is identified, and the triggering lower limit of the microcapsule in the target asphalt pavement is determined based on all the triggering points; the fatigue cycle test is performed on each main test sample based on the triggering lower limit, and the dynamic modulus data of each main test sample after each round of fatigue cycle is collected; the self-healing rate of the target asphalt pavement is determined according to all the dynamic modulus data in the fatigue cycle test, and then the test report of the target asphalt pavement is output based on the self-healing rate.

[0079] Therefore, the application can accurately adapt to the ultrasonic wave transmission characteristics of different pavements by dividing the cylindrical sample into pre-test and main test samples, conducting ultrasonic triggering tests on the pre-test sample at multiple frequencies and powers, collecting ultrasonic echo data, extracting triggering data combined with data trend characteristics, identifying the triggering point of microcapsule triggering rupture to determine the triggering lower limit, avoiding the pavement matrix damage or microcapsule triggering invalid problem caused by fixed ultrasonic parameters in the prior art, and ensuring the authenticity of test data. Based on the triggering lower limit, the fatigue cycle test is conducted on the main test sample, the dynamic modulus data after each cycle is collected to determine the self-healing rate and output the test report, which can objectively reflect the self-healing ability of the pavement under actual stress working conditions. In summary, the application can set the ultrasonic parameters in the test to adapt to the ultrasonic wave transmission characteristics in different pavements.

[0080] Although preferred embodiments of the application have been described, those skilled in the art can make further changes and modifications to these embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to include the preferred embodiments and all changes and modifications falling within the scope of the application.

[0081] Obviously, those skilled in the art can make various modifications and variations to the application without departing from the spirit and scope of the application. Thus, if these modifications and variations of the application fall within the scope of the claims of the application and their equivalent technologies, the application also intends to include these modifications and variations.

Claims

1. A test method for ultrasonically triggered microcapsule asphalt pavement, characterized in that, The method comprises the following steps: Collecting a plurality of cylindrical samples from the target asphalt pavement in advance, the method comprising: Dividing all the cylindrical samples into pre-test samples and main test samples; Performing ultrasonic triggering tests on each pre-test sample at different frequencies and powers, collecting ultrasonic echo data of each pre-test sample during each ultrasonic triggering test, extracting a plurality of triggering data from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data; Identifying triggering points of microcapsule triggering rupture in each triggering data, determining a triggering lower limit of microcapsules in the target asphalt pavement based on all the triggering points; Performing fatigue cycle tests on each main test sample based on the triggering lower limit, and collecting dynamic modulus data of each main test sample after each fatigue cycle; 2. The method of claim 1, wherein, Determining a self-healing rate of the target asphalt pavement according to all the dynamic modulus data in the fatigue cycle test, and outputting a test report of the target asphalt pavement based on the self-healing rate. The ultrasonic triggering test on each pre-test sample specifically comprises: Setting a plurality of test parameters in order from small to large in terms of frequency and power; Selecting a pre-test sample as a selected pre-test sample, and fixing the selected pre-test sample on a test device; Emitting ultrasonic waves on the selected pre-test sample according to each test parameter in turn to complete the ultrasonic triggering test on the selected pre-test sample; 3. The method of claim 1, wherein, Continuing to complete the ultrasonic triggering test on the pre-test sample. The extraction of a plurality of triggering data from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data specifically comprises: For each ultrasonic echo in each ultrasonic echo data, determining an energy change curve of each ultrasonic echo; Extracting a local fluctuation sequence of each energy change curve; Determining a trend characteristic of the corresponding ultrasonic echo of each energy change curve according to the local fluctuation sequence of each energy change curve; 4. The method of claim 1, wherein, Comparing all the trend characteristics with a preset triggering trend threshold, and then extracting a plurality of triggering data from all the ultrasonic echo data. The identification of the triggering points of microcapsule triggering rupture in each triggering data specifically comprises: Selecting a triggering data as a selected triggering data, and determining a time sequence correlation sequence of the selected triggering data; Dividing the selected triggering data into pre-triggering data and post-triggering data according to the time sequence correlation sequence; Fitting the pre-triggering data and the post-triggering data respectively, and then obtaining the triggering points of microcapsule triggering rupture in the selected triggering data; 5. The method of claim 1, wherein, Continuing to determine the triggering points of microcapsule triggering rupture in the remaining triggering data. The determination of the triggering lower limit of microcapsules in the target asphalt pavement based on all the triggering points specifically comprises: Determining an equivalent triggering power of each triggering point; Converting all the triggering points into a power-frequency coordinate system according to the equivalent triggering power; 6. The method of claim 1, wherein, Identifying the triggering lower limit of microcapsules in the target asphalt pavement in the power-frequency coordinate system. The fatigue cycle test on each main test sample based on the triggering lower limit specifically comprises: Selecting a main test sample as a selected main test sample, and fixing the selected main test sample in a fatigue test device; Applying a preset pressure to the selected main test sample for fatigue treatment; The selected main test samples after the fatigue treatment are subjected to ultrasonic scanning according to the trigger lower limit; The selected main test samples after the ultrasonic scanning are subjected to fatigue treatment again under the preset pressure to complete the fatigue cycle test of the selected main test samples; The fatigue cycle test of the remaining main test samples is continuously completed.

7. The method of claim 1, wherein, The self-healing rate of the target asphalt pavement is determined according to all the dynamic modulus data in the fatigue cycle test, and specifically includes: The dynamic modulus drop ratio is determined according to all the dynamic modulus data; The dynamic modulus drop ratio is taken as the self-healing rate of the target asphalt pavement.

8. The method of claim 1, wherein, Ultrasonic echo data of each pre-test sample in each ultrasonic trigger test process are collected through an ultrasonic probe.

9. The method of claim 1, wherein, Dynamic modulus data of each main test sample after each round of fatigue cycle are collected through a static load compression elastic modulus test.

10. A test device for an ultrasonically triggered microcapsule asphalt pavement, characterized in that It includes: A pretreatment module is configured to divide all the cylindrical samples into pre-test samples and main test samples; A processing module is configured to perform ultrasonic trigger tests on each pre-test sample at different frequencies and powers, collect ultrasonic echo data of each pre-test sample in each ultrasonic trigger test process, and extract a plurality of trigger data from all the ultrasonic echo data based on the trend characteristics of all the ultrasonic echo data; The processing module is further configured to identify trigger points of microcapsule trigger rupture in each trigger data, determine a trigger lower limit of microcapsules in the target asphalt pavement based on all the trigger points; A test module is configured to perform fatigue cycle tests on each main test sample based on the trigger lower limit, and collect dynamic modulus data of each main test sample after each round of fatigue cycle; The test module is further configured to determine the self-healing rate of the target asphalt pavement according to all the dynamic modulus data in the fatigue cycle test, and output a test report of the target asphalt pavement based on the self-healing rate.

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