Asphalt mortar abrasion rule analysis method based on unit area fluorescence density

Abstract

The invention discloses an asphalt mortar abrasion rule analysis method based on unit area fluorescence density, which comprises the following steps: preparing an arc-shaped test piece, carrying out an accelerated polishing test, observing the fluorescence form of aggregate before and after abrasion by using a fluorescence microscope, and obtaining a fluorescence image; scanning the surface texture of the aggregate before and after abrasion by using a laser texture scanner and obtaining surface texture elevation data; establishing a unit area fluorescence density calculation model, calculating the unit area fluorescence density, and calculating the reduction amount of the thickness of the asphalt mortar on the surface of the aggregate; and drawing a scatter diagram according to the reduction amount of the thickness of the asphalt mortar on the surface of the aggregate and the fluorescence density per unit area, and performing data fitting to obtain a fitting function and a fitting image of the reduction amount of the thickness of the asphalt mortar on the surface of the aggregate and the fluorescence density per unit area, thereby determining a turning point of rapid attenuation of the skid resistance of the pavement. The anti-skid performance of the pavement is researched from the aspect of abrasion of the thickness of the asphalt mortar film, and the optimal maintenance time is determined.

Description

Technical Field

[0001] The invention belongs to the technical field of road engineering, and in particular relates to an analysis method for asphalt mortar wear law based on unit area fluorescence density. Background Art

[0002] With the rapid development of urban construction in my country, the volume of urban traffic has increased dramatically, and road construction has developed rapidly. However, during the operation of roads, the road surface will be continuously affected by factors such as vehicle load and climate environment. The surface of the road surface is polished, resulting in insufficient anti-skid performance, which leads to traffic safety problems. The anti-skid performance of the road surface depends on both the macro-texture morphology and micro-texture morphology of the road surface: the macro-texture morphology not only affects the deformation characteristics of the tire, but also affects the contact morphology of the interface in the road friction system. This effect is more significant when the vehicle speed is high; the micro-texture morphology can increase the degree of engagement between the tire and the road surface, which is the main reason for the formation of friction during low-speed driving of the vehicle. Therefore, the surface texture of the road surface is one of the most important factors affecting the anti-skid performance of the road surface.

[0003] At present, the mainstream pavement anti-skid performance test methods include direct measurement (such as lateral force coefficient test method, pendulum friction meter method, dynamic rotation friction coefficient tester method, etc.) and indirect measurement (such as sand spreading method, laser scanning method, etc.), but both types of test methods have certain limitations. The lateral force coefficient test method and the dynamic rotation friction coefficient tester method can directly measure the pavement anti-skid index, but the cost is high and may affect traffic; although the sand spreading method and the pendulum friction meter method are easy to operate, they are greatly affected by human factors, and the test accuracy is difficult to guarantee. In addition, the sand spreading method can only test macro textures, and the pendulum friction meter method is only an indirect representation of micro textures.

[0004] Judging from the current status and research data of the anti-skid performance of asphalt pavements at home and abroad, one year after a newly built asphalt road is opened to traffic, the friction coefficient of the pavement will increase due to the damage of the asphalt mortar film on the aggregate surface.

[0005] When the asphalt mortar film on the aggregate surface is worn away and the friction factor is provided by the micro-texture of the aggregate surface, it will transition to the wear and polishing stage of the aggregate, which is manifested as the attenuation of the pavement friction factor, that is, the three stages of the pavement anti-skid performance decay, which are the short-term improvement stage, the rapid attenuation stage and the gradual flattening stage. However, the process of the short-term improvement stage is relatively short, resulting in the existing research often failing to catch this critical period of short-term improvement in time, or failing to give sufficient attention and monitoring.

[0006] It can be seen from this that the initial anti-skid performance of the pavement is closely related to the asphalt mortar film on the aggregate surface. Studying the decay law of the anti-skid performance of the pavement from the perspective of the thickness of the asphalt mortar film is an innovative idea, especially today when high-quality aggregates have become non-renewable resources. Studying the anti-skid performance of the pavement from the perspective of the thickness of the asphalt mortar film, finding the turning point of the rapid decay of the anti-skid performance of the pavement and proposing the appropriate maintenance time based on this, is not only conducive to carrying out maintenance and repair work on the surface texture of the pavement before the micro-texture of the aggregate begins to wear, but also can greatly reduce the risk of excessive wear of the aggregate and minimize the consumption of high-quality aggregate. Therefore, it is urgent to develop an analysis method for the wear law of asphalt mortar based on the unit area fluorescence density, and establish the relationship between the unit area fluorescence density and the thickness or wear of the asphalt mortar film, so as to better extend the anti-skid life of the pavement and maximize the benefits of the pavement throughout its life cycle. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides an analysis method for the wear law of asphalt mortar based on the fluorescence density per unit area, and the analysis method comprises the following steps in chronological order:

[0008] Step 1: preparing fluorescent asphalt;

[0009] Step 2: preparing asphalt mixture;

[0010] Step 3: Prepare arc specimens for accelerated polishing test;

[0011] Step 4: Use an accelerated polishing machine to perform an accelerated polishing test on the arc-shaped specimen, use a fluorescence microscope to observe the fluorescence morphology of the aggregate before and after the accelerated polishing test and obtain the fluorescence image of the aggregate, and use a laser texture scanner to scan the surface texture of the aggregate before and after the accelerated polishing test and obtain the surface texture elevation data of the aggregate;

[0012] Step 5: Conduct fluorescence measurement on the obtained fluorescence image of the aggregate, establish a calculation model for the fluorescence density per unit area, and calculate the fluorescence density per unit area according to the calculation model; at the same time, calculate the reduction in the thickness of the asphalt mortar on the aggregate surface according to the obtained surface texture elevation data of the aggregate;

[0013] Step six: Draw a scatter plot based on the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area, and analyze the correlation between the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area based on the Pearson correlation calculation method and the Spearman correlation calculation method. If the correlation between the two is significant, perform data fitting to obtain the fitting function and fitting image of the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area. Determine the turning point of the rapid attenuation of the pavement's anti-skid performance based on the fitting function and the fitting image, and use the turning point as the optimal maintenance time, otherwise conduct the accelerated polishing test again.

[0014] Preferably, in step one, the fluorescent asphalt is composed of an oil-soluble fluorescent tracer and decolorized asphalt, and the mass ratio of the oil-soluble fluorescent tracer to the decolorized asphalt is 1-1.5:1000.

[0015] In any of the above schemes, preferably, in step 1, the method for preparing the fluorescent asphalt comprises the following steps in chronological order:

[0016] Step (1): weighing an oil-soluble fluorescent tracer and decolorized asphalt according to a set ratio for later use;

[0017] Step (2): placing the decolorized asphalt in a container, and then placing the container containing the decolorized asphalt in an oven to heat the decolorized asphalt until it is in a fluid state, the heating temperature is 135-145° C., and the heating time is 1-1.5 hours;

[0018] Step (3): taking the container containing the decolorized asphalt out of the oven, dripping the oil-soluble fluorescent tracer into the container, and then placing the container containing the decolorized asphalt and the oil-soluble fluorescent tracer into the oil bath pot of the high-speed shearing machine, and performing shear stirring, the shear stirring temperature is 135-145°C, the shear stirring rate is 4000-5000r / min, the shear stirring time is 15-20min, and after the shear stirring is completed, the fluorescent asphalt is obtained;

[0019] Step (4): Take the container containing the fluorescent asphalt out of the oil bath, and then put it into an oven at a temperature of 150-160°C to keep it warm for later use.

[0020] In any of the above schemes, it is preferred that in step 2, the mass percentage of each substance in the asphalt mixture is 4.5-4.6wt% fluorescent asphalt, 44-46wt% coarse aggregate, 44-46wt% fine aggregate, and 5.5-5.8wt% mineral powder.

[0021] The particle sizes of the coarse aggregate include 13.2mm, 9.5mm and 4.75mm. The mass percentage of the materials of each particle size in the coarse aggregate is as follows: the coarse aggregate with a particle size of 13.2mm accounts for 8-12wt%, the coarse aggregate with a particle size of 9.5mm accounts for 38-42wt%, and the coarse aggregate with a particle size of 4.75mm accounts for 46-52wt%.

[0022] The particle sizes of the fine aggregate include 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm and 0.075mm. The mass percentage of the materials of each particle size in the fine aggregate is as follows: the fine aggregate with a particle size of 2.36mm accounts for 32-36wt%, the fine aggregate with a particle size of 1.18mm accounts for 20-22wt%, the fine aggregate with a particle size of 0.6mm accounts for 12-18wt%, the fine aggregate with a particle size of 0.3mm accounts for 10-12wt%, the fine aggregate with a particle size of 0.15mm accounts for 5-10wt%, and the fine aggregate with a particle size of 0.075mm accounts for 6-10wt%.

[0023] In any of the above schemes, preferably, in step 2, the method for preparing the asphalt mixture comprises the following steps in order:

[0024] Step (1): weigh fluorescent asphalt, coarse aggregates of various particle sizes, fine aggregates of various particle sizes, and mineral powder according to a set ratio for later use, wherein the fluorescent asphalt is placed in an oven at a temperature of 150-160° C. for heat preservation;

[0025] Step (2): placing coarse aggregates of various particle sizes, fine aggregates of various particle sizes, and mineral powder into an oven for heating at a temperature of 100-110° C. for a heating time of 4-6 hours;

[0026] Step (3): heat the mixing pot to 160-170° C., firstly put the heated coarse aggregates of various particle sizes and fine aggregates of various particle sizes into the mixing pot and stir for 1-1.5 minutes to evenly mix the coarse aggregates and the fine aggregates; then add the fluorescent asphalt being insulated into the mixing pot and continue stirring for 1-1.5 minutes; finally, add the heated mineral powder into the mixing pot and continue stirring until the materials in the mixing pot are evenly mixed, thus obtaining an asphalt mixture;

[0027] Step (4): Place the obtained asphalt mixture on a tray and place it in a ventilated place to dry naturally.

[0028] In any of the above solutions, preferably, in step 3, the method for preparing the arc-shaped test piece comprises the following steps in order:

[0029] Step (1): selecting aggregate particles with a particle size of 9.5-13.2 mm from the air-dried asphalt mixture, and arranging the aggregate particles tightly in a curved mold, wherein the bottom surface and the surface where the opening end of the inner cavity of the curved mold are both curved surfaces, the inner cavity height of the curved mold is 15 mm, and only one layer of aggregate particles is arranged in the curved mold, and the height of the aggregate particles is smaller than the inner cavity height of the curved mold;

[0030] Step (2): Use fine sand to fill the gaps between the aggregate particles tightly. The particle size of the fine sand is not greater than 0.3 mm. Before filling, place the fine sand in an oven and heat it at a temperature of 100-110° C. for 4-6 hours.

[0031] Step (3): Filling the arc-shaped mold with epoxy resin mortar, using a scraper to fill the epoxy resin mortar densely, and repeatedly smoothing the surface so that the filled epoxy resin mortar is flush with the arc surface where the opening end of the arc-shaped mold is located, the epoxy resin mortar is composed of epoxy resin, ethylenediamine curing agent and fine sand, the mass ratio of epoxy resin, ethylenediamine curing agent and fine sand is 20:3.5:90, and the particle size of the fine sand is not more than 0.3 mm;

[0032] Step (4): Place the arc-shaped mold containing the material in an oven for curing at a temperature of 40-50° C. for 3-5 hours, and then cool naturally for at least 9 hours. After demolding, the arc-shaped specimen is obtained.

[0033] In any of the above schemes, preferably, in step 4, an accelerated polishing test is performed on the arc-shaped test piece using an accelerated polishing machine, and the accelerated polishing test includes the following steps in chronological order:

[0034] Step (1): a plurality of arc-shaped test pieces for the accelerated polishing test are numbered in sequence and arranged in sequence on a road wheel of an accelerated polishing machine so that the aggregate particles are arranged on the outermost sides of the arc-shaped test pieces; an asbestos rubber gasket is arranged between two adjacent arc-shaped test pieces, the shape of the asbestos rubber gasket is similar to the shape of the end of the arc-shaped test piece, and the size of the asbestos rubber gasket is smaller than the size of the end of the arc-shaped test piece; then an outer plate is covered on the road wheel, and the road wheel is installed on the wheel axle;

[0035] Step (2): installing the rubber wheel on the adjustment arm of the accelerated polishing machine so that the rubber wheel is located above the road wheel, an arc-shaped test piece is between the rubber wheel and the road wheel, and the rubber wheel contacts the aggregate particles on the arc-shaped test piece; injecting water for cooling and corundum for accelerated polishing into the contact portion between the rubber wheel and the aggregate particles, the water and corundum are respectively stored in a water storage tank and a sand storage hopper of the accelerated polishing machine, the water flow rate is 60 ml / min, and the corundum flow rate is 27±7 g / min;

[0036] Step (3): Start the accelerated polishing machine to perform an accelerated polishing test on the arc specimen, stop after each abrasion several times, use a fluorescence microscope to observe the fluorescence morphology at the same position on the same aggregate particle on the same arc specimen and obtain the fluorescence image of the aggregate, and use a laser texture scanner to scan the surface texture of the aggregate and obtain the surface texture elevation data of the aggregate; when the fluorescence morphology at the same position on the same aggregate particle on the same arc specimen changes slightly, increase the number of abrasion times, that is, increase the observation interval, and one rotation of the road wheel is considered as one abrasion, until the reduction in the thickness of the asphalt mortar on the aggregate surface tends to be stable, then stop the accelerated polishing test.

[0037] In any of the above schemes, it is preferred that in step four, the accelerated polishing test is adjusted through ten rounds of abrasion times. After each round of abrasion, the total number of abrasion times experienced by the arc specimen is 30 abrasions, 80 abrasions, 140 abrasions, 240 abrasions, 340 abrasions, 440 abrasions, 540 abrasions, 640 abrasions, 740 abrasions, and 840 abrasions, respectively. After the tenth round of abrasion times adjustment, the reduction in the thickness of the asphalt mortar on the aggregate surface tends to be stable.

[0038] In any of the above schemes, preferably, in step 5, a wear area is framed on the obtained fluorescence image, and then the wear area is divided into three equal wear units along the wear direction, and the calculation model of the unit area fluorescence density of each wear unit is: In the formula,

[0039] I——fluorescence density per unit area of ​​each wear unit, dimensionless;

[0040] IOD——Integrated fluorescence density, dimensionless;

[0041] α——fluorescence area ratio, dimensionless;

[0042] A——The area of ​​fluorescence reflection in each wear unit, pixels 2 ;

[0043] A0——The area of ​​each wear unit, pixels 2 ;

[0044] At the same time, the surface texture elevation data of the aggregate in each wear unit is measured, and the reduction in the thickness of the asphalt mortar on the surface of the aggregate in each wear unit is calculated.

[0045] In the present invention, when performing the accelerated polishing test, the fluorescence images of the same position of the same aggregate on the same arc-shaped specimen at different abrasion times are taken by a fluorescence microscope. Although the aggregate particles are arranged as regularly as possible, it is impossible to avoid the shape of the aggregate particles being similar to a prism or a truncated cone, and the lower part of the aggregate particles cannot be worn. Therefore, the wear area is framed on the fluorescence image according to the characteristics of the aggregate particles. In addition, after the asphalt mixture is prepared, its surface is coated with a layer of asphalt mortar, and the surface of the asphalt mixture is uneven and unevenly distributed. Therefore, according to the distribution of protrusions and the direction of gullies on the surface of the asphalt mixture, and combined with the characteristics of the scanning equipment, the wear area is divided into three equal parts along the wear direction, and each part is a wear unit.

[0046] In any of the above schemes, it is preferred that in step six, for the same position on the same aggregate particle on the same arc specimen, a wear unit is taken at different wear times, and a scatter plot between the reduction in the thickness of the asphalt mortar on the aggregate surface and the fluorescence density per unit area in the wear unit is drawn; if the correlation coefficient between the two is greater than 0.7 and the P value (Sig value or significance value) is less than 0.01 or 0.01<P<0.05, it means that the relationship between the two sets of data is very close and significantly correlated at the level of 0.01 or 0.05, then data fitting is performed; after correlation analysis, the fitting function model between the reduction in the thickness of the asphalt mortar on the aggregate surface and the fluorescence density per unit area is obtained as follows: Where, x is the reduction in thickness of asphalt mortar on the aggregate surface, mm;

[0047] t——the reduction in the thickness of the asphalt mortar on the aggregate surface corresponding to the intersection of the two functions, mm;

[0048] n is the reduction in thickness of the asphalt mortar corresponding to the time when the reduction in thickness of the asphalt mortar on the aggregate surface tends to be stable, mm; A, B, C, β0, β1 are model parameters, dimensionless.

[0049] The asphalt mixture of the present invention is composed of fluorescent asphalt, coarse aggregate, fine aggregate and mineral powder, wherein the outer surface of the coarse aggregate is coated with a layer of asphalt mortar film, and the asphalt mortar film is composed of fluorescent asphalt, fine aggregate and mineral powder. The particle sizes are 13.2mm, 9.5mm, 4.75mm, 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm and 0.075mm, i.e., 13.2mm≤particle size<16mm, 9.5mm≤particle size<13.2mm, 4.75mm≤particle size<9.5mm, 2.36mm≤particle size<4.75mm, 1.18mm≤particle size<2.36mm, 0.6≤particle size<1.18mm, 0.3≤particle size<0.6mm, 0.15≤particle size<0.3mm, 0.075≤particle size<0.15mm. For example, the particle size is 2.36mm, i.e., the material is 2.36mm≤particle size<4.75mm obtained by passing the material through 4.75mm sieve holes and 2.36mm sieve holes in sequence.

[0050] When preparing fluorescent asphalt, an oil-soluble fluorescent tracer is used. This fluorescent tracer will not be unevenly dispersed and the dosage is extremely small. Compared with other modifiers that can be used as fluorescent tracers, the oil-soluble fluorescent tracer has little effect on the initial performance indicators of asphalt, which can even be ignored.

[0051] The analysis method of asphalt mortar wear law based on unit area fluorescence density of the present invention has the following beneficial effects:

[0052] (1) The present invention applies the oil-soluble fluorescent tracer used in the fields of oil pipelines to the research of pavement materials for the first time, and can achieve excellent results even with a very small dosage, with little or even negligible impact on the initial performance indicators of asphalt.

[0053] (2) The present invention has achieved innovation in the field of research on pavement anti-skid performance, breaking through the measurement methods that rely on traditional indicators such as friction coefficient, pendulum value and structural depth. By focusing on the wear of asphalt mortar film, the anti-skid performance is deeply analyzed from the perspective of micro-texture morphology, making up for the deficiency of traditional methods that ignore the influence of mortar.

[0054] (3) The method of the present invention can more accurately evaluate the anti-skid properties of the pavement at the microscopic level, reveal the effects of different compositions and structures on wear performance, and provide a new research path for pavement material design and performance improvement. It can also guide researchers and engineers to develop more wear-resistant and more stable materials, helping to ensure that the road surface maintains sufficient anti-skid properties under different usage conditions, thereby improving driving safety.

[0055] (4) The present invention proposes that the maintenance timing is more in line with the actual situation of road wear from the perspective of the turning point of asphalt mortar film wear. It can not only effectively protect the macro-texture and micro-texture of the road surface and greatly extend the service life of the road, but also save the use of high-quality aggregates, thereby promoting environmental friendliness and the realization of carbon neutrality goals.

[0056] (5) The present invention can more accurately evaluate the wear of asphalt mortar by analyzing the fluorescence density per unit area. This method can provide more detailed wear patterns than traditional methods, thereby helping to more accurately combine the anti-skid performance of pavement materials with actual needs. Based on this precise wear analysis, maintenance and repair strategies can be formulated more effectively, reducing unnecessary maintenance work, thereby extending the service life of the road and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a flow chart of a preferred embodiment of the method for analyzing the wear law of asphalt mortar based on the fluorescence density per unit area according to the present invention;

[0058] Figure 2 for Figure 1 A real photo of the arc-shaped test piece prepared in the embodiment shown;

[0059] Figure 3 for Figure 1 A schematic diagram of the wear principle of an accelerated polishing test on a curved specimen using an accelerated polishing machine in the embodiment shown;

[0060] Figure 4 for Figure 1 Fluorescent image photographs of the same position on the same aggregate particle on the same arc-shaped specimen before and after the accelerated polishing test in the illustrated embodiment, wherein: (a) no abrasion, (b) abrasion 30 times, (c) abrasion 80 times, (d) abrasion 140 times, (e) abrasion 240 times, (f) abrasion 340 times, (g) abrasion 440 times, (h) abrasion 540 times, (i) abrasion 640 times, (j) abrasion 740 times, (k) abrasion 840 times;

[0061] Figure 5 for Figure 1 In the embodiment shown, a scatter plot of the reduction in thickness of the asphalt mortar on the aggregate surface and the fluorescence density per unit area at the same position on the same aggregate particle on the same arc-shaped specimen at different abrasion times;

[0062] Figure 6 for Figure 1 The fitting image between the reduction in thickness of the asphalt mortar on the aggregate surface and the fluorescence density per unit area after correlation analysis in the embodiment shown.

[0063] Notes in the figure: 1-arc specimen, 2-aggregate particles, 3-road wheel, 4-rubber wheel. DETAILED DESCRIPTION

[0064] In order to further understand the content of the present invention, the present invention will be described in detail below in conjunction with specific embodiments.

[0065] Embodiment 1:

[0066] like Figure 1 As shown, according to a preferred embodiment of the method for analyzing the wear law of asphalt mortar based on the unit area fluorescence density of the present invention, the analysis method includes the following steps in chronological order:

[0067] Step 1: preparing fluorescent asphalt;

[0068] Step 2: preparing asphalt mixture;

[0069] Step 3: Prepare arc specimens for accelerated polishing test;

[0070] Step 4: Use an accelerated polishing machine to perform an accelerated polishing test on the arc-shaped specimen, use a fluorescence microscope to observe the fluorescence morphology of the aggregate before and after the accelerated polishing test and obtain the fluorescence image of the aggregate, and use a laser texture scanner to scan the surface texture of the aggregate before and after the accelerated polishing test and obtain the surface texture elevation data of the aggregate;

[0071] Step 5: Conduct fluorescence measurement on the obtained fluorescence image of the aggregate, establish a calculation model for the fluorescence density per unit area, and calculate the fluorescence density per unit area according to the calculation model; at the same time, calculate the reduction in the thickness of the asphalt mortar on the aggregate surface according to the obtained surface texture elevation data of the aggregate;

[0072] Step six: Draw a scatter plot based on the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area, and analyze the correlation between the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area based on the Pearson correlation calculation method and the Spearman correlation calculation method. If the correlation between the two is significant, perform data fitting to obtain the fitting function and fitting image of the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area. Determine the turning point of the rapid attenuation of the pavement's anti-skid performance based on the fitting function and the fitting image, and use the turning point as the optimal maintenance time, otherwise conduct the accelerated polishing test again.

[0073] In step 1, the fluorescent asphalt is composed of an oil-soluble fluorescent tracer and decolorized asphalt, and the mass ratio of the oil-soluble fluorescent tracer to the decolorized asphalt is 1.2:1000. The preparation method of the fluorescent asphalt comprises the following steps in order:

[0074] Step (1): weighing an oil-soluble fluorescent tracer and decolorized asphalt according to a set ratio for later use;

[0075] Step (2): placing the decolorized asphalt in a container, and then placing the container containing the decolorized asphalt in an oven to heat the decolorized asphalt until it is in a fluid state, the heating temperature is 140° C., and the heating time is 1.2 h;

[0076] Step (3): taking the container containing the decolorized asphalt out of the oven, dripping the oil-soluble fluorescent tracer into the container, and then placing the container containing the decolorized asphalt and the oil-soluble fluorescent tracer into the oil bath pot of the high-speed shearing machine, and performing shear stirring. The shear stirring temperature is 140° C., the shear stirring rate is 4500 r / min, and the shear stirring time is 18 min. After the shear stirring is completed, the fluorescent asphalt is obtained.

[0077] Step (4): Take the container containing the fluorescent asphalt out of the oil bath, and then put it into an oven at 155°C to keep it warm for later use.

[0078] In step 2, the mass percentage of each substance in the asphalt mixture is 4.5wt% of fluorescent asphalt, 44wt% of coarse aggregate, 46wt% of fine aggregate, and 5.5wt% of mineral powder. The particle sizes of the coarse aggregate include 13.2mm, 9.5mm, and 4.75mm. The mass percentage of the substances in each particle size of the coarse aggregate is 10wt% of the coarse aggregate with a particle size of 13.2mm, 40wt% of the coarse aggregate with a particle size of 9.5mm, and 50wt% of the coarse aggregate with a particle size of 4.75mm. The particle sizes of the fine aggregate include 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm and 0.075mm. The mass percentage of the material of each particle size in the fine aggregate is as follows: the fine aggregate with a particle size of 2.36mm accounts for 34wt%, the fine aggregate with a particle size of 1.18mm accounts for 21wt%, the fine aggregate with a particle size of 0.6mm accounts for 18wt%, the fine aggregate with a particle size of 0.3mm accounts for 11wt%, the fine aggregate with a particle size of 0.15mm accounts for 8wt%, and the fine aggregate with a particle size of 0.075mm accounts for 8wt%.

[0079] The method for preparing the asphalt mixture comprises the following steps in order:

[0080] Step (1): weigh fluorescent asphalt, coarse aggregates of various particle sizes, fine aggregates of various particle sizes, and mineral powder according to a set ratio for later use, wherein the fluorescent asphalt is placed in an oven at a temperature of 155° C. for heat preservation;

[0081] Step (2): placing coarse aggregates of various particle sizes, fine aggregates of various particle sizes, and mineral powder into an oven and heating them at a temperature of 105° C. for 5 hours;

[0082] Step (3): heat the mixing pot to 165° C., firstly put the heated coarse aggregates of various particle sizes and fine aggregates of various particle sizes into the mixing pot and stir for 1.2 minutes to evenly mix the coarse aggregates and fine aggregates; then add the fluorescent asphalt being insulated into the mixing pot and continue stirring for 1.2 minutes; finally, add the heated mineral powder into the mixing pot and continue stirring until the materials in the mixing pot are evenly mixed, thereby obtaining an asphalt mixture;

[0083] Step (4): Place the obtained asphalt mixture on a tray and place it in a ventilated place to dry naturally.

[0084] In step 3, the method for preparing the arc-shaped test piece comprises the following steps in order:

[0085] Step (1): selecting aggregate particles with a particle size of 9.5-13.2 mm from the air-dried asphalt mixture, and arranging the aggregate particles tightly in a curved mold, wherein the bottom surface and the surface where the opening end of the inner cavity of the curved mold are both curved surfaces, the inner cavity height of the curved mold is 15 mm, and only one layer of aggregate particles is arranged in the curved mold, and the height of the aggregate particles is smaller than the inner cavity height of the curved mold;

[0086] Step (2): Use fine sand to fill the gaps between the aggregate particles tightly. The particle size of the fine sand is not greater than 0.3 mm. Before filling, place the fine sand in an oven and heat it at a temperature of 105° C. for 5 hours.

[0087] Step (3): Filling the arc-shaped mold with epoxy resin mortar, using a scraper to fill the epoxy resin mortar densely, and repeatedly smoothing the surface so that the filled epoxy resin mortar is flush with the arc surface where the opening end of the arc-shaped mold is located, the epoxy resin mortar is composed of epoxy resin, ethylenediamine curing agent and fine sand, the mass ratio of epoxy resin, ethylenediamine curing agent and fine sand is 20:3.5:90, and the particle size of the fine sand is not more than 0.3 mm;

[0088] Step (4): Place the arc-shaped mold containing the material in an oven for curing at a temperature of 45°C for 4 hours, then cool naturally for at least 9 hours, and obtain an arc-shaped specimen after demoulding. The actual photo of the arc-shaped specimen prepared in this embodiment is shown in FIG. Figure 2 shown.

[0089] In step 4, an accelerated polishing machine is used to perform an accelerated polishing test on the arc specimen. The wear principle is as follows: Figure 3 As shown, the accelerated polishing test includes the following steps in order:

[0090] Step (1): a plurality of arc-shaped test pieces 1 for an accelerated polishing test are numbered in sequence and arranged in sequence on a road wheel 3 of an accelerated polishing machine so that the aggregate particles 2 are arranged on the outermost side of the arc-shaped test piece 1; an asbestos rubber gasket is arranged between two adjacent arc-shaped test pieces, the shape of the asbestos rubber gasket being similar to the shape of the end of the arc-shaped test piece and the size of the asbestos rubber gasket being smaller than the size of the end of the arc-shaped test piece, and then an outer plate is covered on the road wheel, and the road wheel is mounted on the wheel axle;

[0091] Step (2): Install the rubber wheel 4 on the adjustment arm of the accelerated polishing machine so that the rubber wheel 4 is located above the road wheel 3, the arc test piece 1 is between the rubber wheel 4 and the road wheel 3, and the rubber wheel 4 is in contact with the aggregate particles 2 on the arc test piece 1; inject water for cooling and corundum for accelerated polishing into the contact portion between the rubber wheel and the aggregate particles, the water and corundum are respectively stored in the water storage tank and the sand storage hopper of the accelerated polishing machine, the water flow rate is 60 ml / min, and the corundum flow rate is 27±7 g / min;

[0092] Step (3): Start the accelerated polishing machine to perform an accelerated polishing test on the arc specimen, stop after each abrasion several times, use a fluorescence microscope to observe the fluorescence morphology at the same position on the same aggregate particle on the same arc specimen and obtain the fluorescence image of the aggregate, and use a laser texture scanner to scan the surface texture of the aggregate and obtain the surface texture elevation data of the aggregate; when the fluorescence morphology at the same position on the same aggregate particle on the same arc specimen changes slightly, increase the number of abrasion times, that is, increase the observation interval, and one rotation of the road wheel is considered as one abrasion, until the reduction in the thickness of the asphalt mortar on the aggregate surface tends to be stable, then stop the accelerated polishing test.

[0093] The accelerated polishing test was adjusted for ten rounds of abrasion times. After each round of abrasion, the total number of abrasion times experienced by the arc specimen was 30 abrasions, 80 abrasions, 140 abrasions, 240 abrasions, 340 abrasions, 440 abrasions, 540 abrasions, 640 abrasions, 740 abrasions, and 840 abrasions, respectively. After the tenth round of abrasion times, the reduction in the thickness of the asphalt mortar on the aggregate surface tended to be stable. The fluorescent images of the same position on the same aggregate particle on the same arc specimen before and after the accelerated polishing test in this embodiment are shown in FIG. Figure 4 As shown, among which: (a) no wear, (b) wear 30 times, (c) wear 80 times, (d) wear 140 times, (e) wear 240 times, (f) wear 340 times, (g) wear 440 times, (h) wear 540 times, (i) wear 640 times, (j) wear 740 times, and (k) wear 840 times.

[0094] In step 5, a wear area is selected on the obtained fluorescence image, and then the wear area is divided into three equal wear units along the wear direction. The calculation model of the unit area fluorescence density of each wear unit is: In the formula,

[0095] I——fluorescence density per unit area of ​​each wear unit, dimensionless;

[0096] IOD——Integrated fluorescence density, dimensionless;

[0097] α——fluorescence area ratio, dimensionless;

[0098] A——The area of ​​fluorescence reflection in each wear unit, pixels 2 ;

[0099] A0——The area of ​​each wear unit, pixels 2 ;

[0100] At the same time, the surface texture elevation data of the aggregate in each wear unit is measured, and the reduction in the thickness of the asphalt mortar on the surface of the aggregate in each wear unit is calculated.

[0101] In step 6, for the same position on the same aggregate particle on the same arc specimen, a wear unit is taken under different wear times, and a scatter plot between the reduction in the thickness of the asphalt mortar on the aggregate surface in the wear unit and the fluorescence density per unit area is drawn, such as Figure 5 shown.

[0102] The correlation between the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area was analyzed according to the Pearson correlation calculation method and the Spearman correlation calculation method. The calculation results are shown in Tables 1 and 2.

[0103] Table 1 Pearson correlation calculation results

[0104]

[0105] Table 2 Spearman correlation coefficient calculation results

[0106]

[0107] The results of Pearson correlation calculation show that the absolute value of the correlation coefficient between the reduction in asphalt mortar thickness and the fluorescence density per unit area is 0.714>0.7 and 0.01<0.02<0.05, so the two are closely related and significantly correlated at the 0.05 level (bilateral). The results of Spearman correlation calculation show that the absolute value of the correlation coefficient between the reduction in asphalt mortar thickness and the fluorescence density per unit area is 0.855>0.7 and 0.002<0.01, so the two are closely related and significantly correlated at the confidence level (bilateral) of 0.01. Therefore, the non-normal distribution model is selected for function fitting.

[0108] After correlation analysis, the fitting function between the reduction in the thickness of the asphalt mortar on the aggregate surface and the fluorescence density per unit area is a cubic model function, but it is contrary to the actual wear law. Therefore, a piecewise function is used to fit the model. After curve fitting analysis, the model function is finally confirmed as follows:

[0109]

[0110] In the formula, the independent variable x is the reduction in the thickness of the asphalt mortar on the aggregate surface. In this embodiment, the fitting image between the reduction in the thickness of the asphalt mortar on the aggregate surface and the fluorescence density per unit area is as follows: Figure 6 As shown in the figure, it can be seen that the reduction in asphalt mortar thickness reaches a turning point at about 0.18mm, so this turning point is taken as the optimal maintenance point of the pavement.

[0111] The asphalt mixture in this embodiment is composed of fluorescent asphalt, coarse aggregate, fine aggregate and mineral powder, wherein the outer surface of the coarse aggregate is coated with a layer of asphalt mortar film, and the asphalt mortar film is composed of fluorescent asphalt, fine aggregate and mineral powder. The particle sizes are 13.2mm, 9.5mm, 4.75mm, 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm and 0.075mm, i.e., 13.2mm≤particle size<16mm, 9.5mm≤particle size<13.2mm, 4.75mm≤particle size<9.5mm, 2.36mm≤particle size<4.75mm, 1.18mm≤particle size<2.36mm, 0.6≤particle size<1.18mm, 0.3≤particle size<0.6mm, 0.15≤particle size<0.3mm, 0.075≤particle size<0.15mm. For example, the particle size is 2.36mm, i.e., the material is 2.36mm≤particle size<4.75mm obtained by passing the material through 4.75mm sieve holes and 2.36mm sieve holes in sequence. The accelerated polishing machine, fluorescent microscope, laser texture scanner, high-speed shearing machine, mixing pot, etc. used in this embodiment can all be traditional equipment, and there is no special requirement for the equipment model.

[0112] The analysis method of asphalt mortar wear law based on unit area fluorescence density in this embodiment has the following beneficial effects:

[0113] (1) The oil-soluble fluorescent tracer used in oil pipelines and other fields was applied to the study of pavement materials for the first time, and it can play an excellent role when the dosage is very small, and has little impact on the initial performance indicators of asphalt. (2) By focusing on the wear of the asphalt mortar film, the anti-skid performance is deeply analyzed from the perspective of micro-texture morphology, which makes up for the deficiency of the traditional method that ignores the influence of mortar. This method can more accurately evaluate the anti-skid characteristics of the pavement at the micro level, reveal the influence of different compositions and structures on the wear performance, and provide a new research path for the design and performance improvement of pavement materials. (3) From the perspective of the turning point of asphalt mortar film wear, it is proposed that the maintenance time is more in line with the actual situation of pavement wear, which can not only effectively protect the macro-texture and micro-texture of the pavement surface, greatly extend the service life of the road, but also save the use of high-quality aggregates, thereby promoting environmental friendliness and the realization of carbon neutrality goals. (4) Through the analysis of unit area fluorescence density, the wear of asphalt mortar can be more accurately evaluated, which helps to more accurately combine the anti-skid performance of pavement materials with actual needs.

[0114] Embodiment 2:

[0115] According to another preferred embodiment of the method for analyzing the wear law of asphalt mortar based on the unit area fluorescence density of the present invention, its analysis process, technical principle, equipment used, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0116] In step 1, the fluorescent asphalt is composed of an oil-soluble fluorescent tracer and a decolorized asphalt, and the mass ratio of the oil-soluble fluorescent tracer to the decolorized asphalt is 1:1000. In the preparation method of the fluorescent asphalt: step (2), the decolorized asphalt is placed in a container, and then the container containing the decolorized asphalt is placed in an oven for heating, and the decolorized asphalt is heated to a fluid state, the heating temperature is 135°C, and the heating time is 1.5h; step (3), the container containing the decolorized asphalt is taken out of the oven, the oil-soluble fluorescent tracer is dripped into the container, and then the container containing the decolorized asphalt and the oil-soluble fluorescent tracer is placed in an oil bath pot of a high-speed shearing machine, and shearing and stirring are performed, the shearing and stirring temperature is 135°C, the shearing and stirring rate is 4000r / min, and the shearing and stirring time is 20min. After the shearing and stirring is completed, the fluorescent asphalt is obtained; step (4), the container containing the fluorescent asphalt is taken out of the oil bath pot, and then placed in an oven at a temperature of 150°C for insulation and standby use.

[0117] In step 2, the mass percentage of each substance in the asphalt mixture is 4.6wt% of fluorescent asphalt, 45wt% of coarse aggregate, 44.6wt% of fine aggregate, and 5.8wt% of mineral powder. The particle sizes of the coarse aggregate include 13.2mm, 9.5mm, and 4.75mm. The mass percentage of each substance in the coarse aggregate is 8wt% of the coarse aggregate with a particle size of 13.2mm, 42wt% of the coarse aggregate with a particle size of 9.5mm, and 50wt% of the coarse aggregate with a particle size of 4.75mm. The particle sizes of the fine aggregate include 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm and 0.075mm. The mass percentage of the material of each particle size in the fine aggregate is as follows: the fine aggregate with a particle size of 2.36mm accounts for 32wt%, the fine aggregate with a particle size of 1.18mm accounts for 22wt%, the fine aggregate with a particle size of 0.6mm accounts for 14wt%, the fine aggregate with a particle size of 0.3mm accounts for 12wt%, the fine aggregate with a particle size of 0.15mm accounts for 10wt%, and the fine aggregate with a particle size of 0.075mm accounts for 10wt%.

[0118] In the preparation method of asphalt mixture, the following steps are taken: step (1), according to a set ratio, fluorescent asphalt, coarse aggregate of various particle sizes, fine aggregate of various particle sizes, and mineral powder are weighed for standby use, wherein the fluorescent asphalt is placed in an oven at a temperature of 150° C. for heat preservation; step (2), the coarse aggregate of various particle sizes, fine aggregate of various particle sizes, and mineral powder are placed in an oven for heating, the heating temperature is 100° C., and the heating time is 6 hours; step (3), the mixing pot is heated to 160° C., firstly, the heated coarse aggregate of various particle sizes and fine aggregate of various particle sizes are placed in the mixing pot and stirred for 1.5 minutes to mix the coarse aggregate and the fine aggregate evenly; then, the fluorescent asphalt being heated is added to the mixing pot and stirred for 1.5 minutes; finally, the heated mineral powder is added to the mixing pot and stirred until the materials in the mixing pot are evenly mixed, so as to obtain the asphalt mixture.

[0119] In step three, in the preparation method of the arc-shaped specimen: step (2), using fine sand to fill the gaps between the aggregate particles densely, the particle size of the fine sand is not more than 0.3 mm, and the fine sand is placed in an oven for heating before filling, the heating temperature is 100°C, and the heating time is 6 hours; step (4), placing the arc-shaped mold containing the material in an oven for curing, the curing temperature is 40°C, the curing time is 5 hours, and then naturally cooling for at least 9 hours, and the arc-shaped specimen is obtained after demolding.

[0120] Embodiment three:

[0121] According to another preferred embodiment of the method for analyzing the wear law of asphalt mortar based on the unit area fluorescence density of the present invention, its analysis process, technical principle, equipment used, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0122] In step 1, the fluorescent asphalt is composed of an oil-soluble fluorescent tracer and a decolorized asphalt, and the mass ratio of the oil-soluble fluorescent tracer to the decolorized asphalt is 1.5:1000. In the preparation method of the fluorescent asphalt: step (2), the decolorized asphalt is placed in a container, and then the container containing the decolorized asphalt is placed in an oven for heating, and the decolorized asphalt is heated to a fluid state, the heating temperature is 145°C, and the heating time is 1h; step (3), the container containing the decolorized asphalt is taken out of the oven, the oil-soluble fluorescent tracer is dripped into the container, and then the container containing the decolorized asphalt and the oil-soluble fluorescent tracer is placed in an oil bath pot of a high-speed shearing machine, and shearing and stirring are performed, the shearing and stirring temperature is 145°C, the shearing and stirring rate is 5000r / min, and the shearing and stirring time is 15min. After the shearing and stirring is completed, the fluorescent asphalt is obtained; step (4), the container containing the fluorescent asphalt is taken out of the oil bath pot, and then placed in an oven at a temperature of 160°C for insulation and standby.

[0123] In step 2, the mass percentage of each substance in the asphalt mixture is 4.5wt% of fluorescent asphalt, 46wt% of coarse aggregate, 44wt% of fine aggregate, and 5.5wt% of mineral powder. The particle sizes of the coarse aggregate include 13.2mm, 9.5mm, and 4.75mm. The mass percentage of each substance in the coarse aggregate is 12wt% of the coarse aggregate with a particle size of 13.2mm, 38wt% of the coarse aggregate with a particle size of 9.5mm, and 50wt% of the coarse aggregate with a particle size of 4.75mm. The particle sizes of the fine aggregate include 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm and 0.075mm. The mass percentage of the materials of each particle size in the fine aggregate is as follows: the fine aggregate with a particle size of 2.36mm accounts for 36wt%, the fine aggregate with a particle size of 1.18mm accounts for 20wt%, the fine aggregate with a particle size of 0.6mm accounts for 16wt%, the fine aggregate with a particle size of 0.3mm accounts for 10wt%, the fine aggregate with a particle size of 0.15mm accounts for 9wt%, and the fine aggregate with a particle size of 0.075mm accounts for 9wt%.

[0124] In the asphalt mixture preparation method, the following steps are taken: step (1), weighing fluorescent asphalt, coarse aggregate of various particle sizes, fine aggregate of various particle sizes, and mineral powder according to a set ratio for standby use, wherein the fluorescent asphalt is placed in an oven at a temperature of 160° C. for heat preservation; step (2), placing the coarse aggregate of various particle sizes, fine aggregate of various particle sizes, and mineral powder in an oven for heating, wherein the heating temperature is 110° C. and the heating time is 4 hours; step (3), heating a mixing pot to 170° C., firstly placing the heated coarse aggregate of various particle sizes and fine aggregate of various particle sizes in the mixing pot and stirring for 1 minute to uniformly mix the coarse aggregate and the fine aggregate; then adding the fluorescent asphalt being heat-insulated into the mixing pot and continuing to stir for 1 minute; finally, adding the heated mineral powder into the mixing pot and continuing to stir until the materials in the mixing pot are uniformly mixed, thereby obtaining the asphalt mixture.

[0125] In step three, in the preparation method of the arc-shaped specimen: step (2), using fine sand to fill the gaps between the aggregate particles densely, the particle size of the fine sand is not more than 0.3 mm, and the fine sand is placed in an oven for heating before filling, the heating temperature is 110°C, and the heating time is 4 hours; step (4), placing the arc-shaped mold containing the material in an oven for curing, the curing temperature is 50°C, the curing time is 3 hours, and then naturally cooling for at least 9 hours, and the arc-shaped specimen is obtained after demolding.

[0126] Special note: The technical solution of the present invention involves many parameters, and the synergistic effects between the various parameters need to be comprehensively considered to obtain the beneficial effects and significant progress of the present invention. Moreover, the value ranges of the various parameters in the technical solution are obtained after a large number of experiments. For each parameter and the combination of each parameter, the inventor has recorded a large amount of experimental data. Due to space limitations, the specific experimental data will not be disclosed here.

[0127] It is not difficult for those skilled in the art to understand that the analysis method of asphalt mortar wear law based on unit area fluorescence density of the present invention includes any combination of the invention content and specific implementation method of the above-mentioned invention specification and the various parts shown in the drawings. Due to the limited space and to make the specification concise, the various schemes composed of these combinations are not described one by one. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An analysis method for asphalt mortar wear law based on unit area fluorescence density, characterized by: The analysis method comprises the following steps in chronological order: Step 1: preparing fluorescent asphalt; Step 2: preparing asphalt mixture; Step 3: Prepare arc specimens for accelerated polishing test; Step 4: Use an accelerated polishing machine to perform an accelerated polishing test on the arc-shaped specimen, use a fluorescence microscope to observe the fluorescence morphology of the aggregate before and after the accelerated polishing test and obtain the fluorescence image of the aggregate, and use a laser texture scanner to scan the surface texture of the aggregate before and after the accelerated polishing test and obtain the surface texture elevation data of the aggregate; Step 5: Conduct fluorescence measurement on the obtained fluorescence image of the aggregate, establish a calculation model for the fluorescence density per unit area, and calculate the fluorescence density per unit area according to the calculation model; at the same time, calculate the reduction in the thickness of the asphalt mortar on the aggregate surface according to the obtained surface texture elevation data of the aggregate; Step six: Draw a scatter plot based on the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area, and analyze the correlation between the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area based on the Pearson correlation calculation method and the Spearman correlation calculation method. If the correlation between the two is significant, perform data fitting to obtain the fitting function and fitting image of the reduction in thickness of asphalt mortar on the aggregate surface and the fluorescence density per unit area. Determine the turning point of the rapid attenuation of the pavement's anti-skid performance based on the fitting function and the fitting image, and use the turning point as the optimal maintenance time, otherwise conduct the accelerated polishing test again.

2. The method for analyzing the wear law of asphalt mortar based on unit area fluorescence density according to claim 1 is characterized in that: In step 1, the fluorescent asphalt is composed of an oil-soluble fluorescent tracer and decolorized asphalt, and the mass ratio of the oil-soluble fluorescent tracer to the decolorized asphalt is 1-1.5:1000.

3. The method for analyzing the wear law of asphalt mortar based on unit area fluorescence density according to claim 2 is characterized in that: In step 1, the method for preparing the fluorescent asphalt comprises the following steps in order: Step (1): weighing an oil-soluble fluorescent tracer and decolorized asphalt according to a set ratio for later use; Step (2): placing the decolorized asphalt in a container, and then placing the container containing the decolorized asphalt in an oven to heat the decolorized asphalt until it is in a fluid state, the heating temperature is 135-145° C., and the heating time is 1-1.5 hours; Step (3): taking the container containing the decolorized asphalt out of the oven, dripping the oil-soluble fluorescent tracer into the container, and then placing the container containing the decolorized asphalt and the oil-soluble fluorescent tracer into the oil bath pot of the high-speed shearing machine, and performing shear stirring, the shear stirring temperature is 135-145°C, the shear stirring rate is 4000-5000r / min, the shear stirring time is 15-20min, and after the shear stirring is completed, the fluorescent asphalt is obtained; Step (4): Take the container containing the fluorescent asphalt out of the oil bath, and then put it into an oven at a temperature of 150-160°C to keep it warm for later use.

4. The method for analyzing the wear law of asphalt mortar based on unit area fluorescence density according to claim 3 is characterized in that: In step 2, the mass percentage of each substance in the asphalt mixture is 4.5-4.6wt% of fluorescent asphalt, 44-46wt% of coarse aggregate, 44-46wt% of fine aggregate, and 5.5-5.8wt% of mineral powder; The particle sizes of the coarse aggregate include 13.2 mm, 9.5 mm and 4.75 mm. The mass percentage of the materials of each particle size in the coarse aggregate is 8-12 wt% of the coarse aggregate with a particle size of 13.2 mm, 38-42 wt% of the coarse aggregate with a particle size of 9.5 mm, and 46-52 wt% of the coarse aggregate with a particle size of 4.75 mm. The particle sizes of the fine aggregate include 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm and 0.075mm. The mass percentage of the materials of each particle size in the fine aggregate is as follows: the fine aggregate with a particle size of 2.36mm accounts for 32-36wt%, the fine aggregate with a particle size of 1.18mm accounts for 20-22wt%, the fine aggregate with a particle size of 0.6mm accounts for 12-18wt%, the fine aggregate with a particle size of 0.3mm accounts for 10-12wt%, the fine aggregate with a particle size of 0.15mm accounts for 5-10wt%, and the fine aggregate with a particle size of 0.075mm accounts for 6-10wt%.

5. The method for analyzing the wear law of asphalt mortar based on unit area fluorescence density according to claim 4 is characterized in that: In step 2, the method for preparing the asphalt mixture comprises the following steps in order: Step (1): weigh fluorescent asphalt, coarse aggregates of various particle sizes, fine aggregates of various particle sizes, and mineral powder according to a set ratio for later use, wherein the fluorescent asphalt is placed in an oven at a temperature of 150-160° C. for heat preservation; Step (2): placing coarse aggregates of various particle sizes, fine aggregates of various particle sizes, and mineral powder into an oven for heating at a temperature of 100-110° C. for a heating time of 4-6 hours; Step (3): heat the mixing pot to 160-170° C., firstly put the heated coarse aggregates of various particle sizes and fine aggregates of various particle sizes into the mixing pot and stir for 1-1.5 minutes to evenly mix the coarse aggregates and the fine aggregates; then add the fluorescent asphalt being insulated into the mixing pot and continue stirring for 1-1.5 minutes; finally, add the heated mineral powder into the mixing pot and continue stirring until the materials in the mixing pot are evenly mixed, thus obtaining an asphalt mixture; Step (4): Place the obtained asphalt mixture on a tray and place it in a ventilated place to dry naturally.

6. The method for analyzing the wear law of asphalt mortar based on unit area fluorescence density according to claim 5 is characterized in that: In step 3, the method for preparing the arc-shaped test piece comprises the following steps in order: Step (1): selecting aggregate particles with a particle size of 9.5-13.2 mm from the air-dried asphalt mixture, and arranging the aggregate particles tightly in a curved mold, wherein the bottom surface and the surface where the opening end of the inner cavity of the curved mold are both curved surfaces, the inner cavity height of the curved mold is 15 mm, and only one layer of aggregate particles is arranged in the curved mold, and the height of the aggregate particles is smaller than the inner cavity height of the curved mold; Step (2): Use fine sand to fill the gaps between the aggregate particles tightly. The particle size of the fine sand is not greater than 0.3 mm. Before filling, place the fine sand in an oven and heat it at a temperature of 100-110° C. for 4-6 hours. Step (3): Filling the arc-shaped mold with epoxy resin mortar, using a scraper to fill the epoxy resin mortar densely, and repeatedly smoothing the surface so that the filled epoxy resin mortar is flush with the arc surface where the opening end of the arc-shaped mold is located, the epoxy resin mortar is composed of epoxy resin, ethylenediamine curing agent and fine sand, the mass ratio of epoxy resin, ethylenediamine curing agent and fine sand is 20:3.5:90, and the particle size of the fine sand is not more than 0.3 mm; Step (4): Place the arc-shaped mold containing the material in an oven for curing at a temperature of 40-50° C. for 3-5 hours, and then cool naturally for at least 9 hours. After demolding, the arc-shaped specimen is obtained.

7. The method for analyzing the wear law of asphalt mortar based on unit area fluorescence density according to claim 6 is characterized in that: In step 4, an accelerated polishing machine is used to perform an accelerated polishing test on the arc-shaped specimen. The accelerated polishing test includes the following steps in chronological order: Step (1): a plurality of arc-shaped test pieces for the accelerated polishing test are numbered in sequence and arranged in sequence on a road wheel of an accelerated polishing machine so that the aggregate particles are arranged on the outermost sides of the arc-shaped test pieces; an asbestos rubber gasket is arranged between two adjacent arc-shaped test pieces, the shape of the asbestos rubber gasket is similar to the shape of the end of the arc-shaped test piece, and the size of the asbestos rubber gasket is smaller than the size of the end of the arc-shaped test piece; then an outer plate is covered on the road wheel, and the road wheel is installed on the wheel axle; Step (2): installing the rubber wheel on the adjustment arm of the accelerated polishing machine so that the rubber wheel is located above the road wheel, an arc-shaped test piece is between the rubber wheel and the road wheel, and the rubber wheel contacts the aggregate particles on the arc-shaped test piece; injecting water for cooling and corundum for accelerated polishing into the contact portion between the rubber wheel and the aggregate particles, the water and corundum are respectively stored in a water storage tank and a sand storage hopper of the accelerated polishing machine, the water flow rate is 60 ml / min, and the corundum flow rate is 27±7 g / min; Step (3): Start the accelerated polishing machine to perform an accelerated polishing test on the arc specimen, stop after each abrasion several times, use a fluorescence microscope to observe the fluorescence morphology at the same position on the same aggregate particle on the same arc specimen and obtain the fluorescence image of the aggregate, and use a laser texture scanner to scan the surface texture of the aggregate and obtain the surface texture elevation data of the aggregate; when the fluorescence morphology at the same position on the same aggregate particle on the same arc specimen changes slightly, increase the number of abrasion times, that is, increase the observation interval, and one rotation of the road wheel is considered as one abrasion, until the reduction in the thickness of the asphalt mortar on the aggregate surface tends to be stable, then stop the accelerated polishing test.

8. The method for analyzing the wear law of asphalt mortar based on unit area fluorescence density according to claim 7 is characterized in that: In step 5, a wear area is selected on the obtained fluorescence image, and then the wear area is divided into three equal wear units along the wear direction. The calculation model of the unit area fluorescence density of each wear unit is: In the formula, I——fluorescence density per unit area of ​​each wear unit, dimensionless; IOD——Integrated fluorescence density, dimensionless; α——fluorescence area ratio, dimensionless; A——The area of ​​fluorescence reflection in each wear unit, pixels 2 ; A0——The area of ​​each wear unit, pixels 2 ; At the same time, the surface texture elevation data of the aggregate in each wear unit is measured, and the reduction in the thickness of the asphalt mortar on the surface of the aggregate in each wear unit is calculated.

9. The method for analyzing the wear law of asphalt mortar based on unit area fluorescence density according to claim 8, characterized in that: In step 6, for the same position on the same aggregate particle on the same arc specimen, a wear unit is taken at different wear times, and a scatter plot between the reduction in the thickness of the asphalt mortar on the aggregate surface and the fluorescence density per unit area in the wear unit is drawn; after correlation analysis, the fitting function model between the reduction in the thickness of the asphalt mortar on the aggregate surface and the fluorescence density per unit area is obtained as follows: In the formula, x——reduction in thickness of asphalt mortar on aggregate surface, mm; t——the reduction in the thickness of the asphalt mortar on the aggregate surface corresponding to the intersection of the two functions, mm; n is the reduction in thickness of the asphalt mortar corresponding to the time when the reduction in thickness of the asphalt mortar on the aggregate surface tends to be stable, mm; A, B, C, β0, β1 are model parameters, dimensionless.

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