CN106680158A - Asphalt mixture separation degree estimation method and device - Google Patents

Abstract

The invention provides an evaluation index of coarse aggregate segregation degree, a coarse aggregate segregation test device, and a method for estimating the segregation degree of asphalt mixture. The value is used as the evaluation index of segregation degree. 2) The test device includes a bracket, and a funnel is fixed on the bracket. The funnel is used to hold the coarse aggregate mixed according to the proportion. Concentric isolation barrels with different inner diameters, the isolation barrels pass through the falling receiving tray, and the coarse aggregate enters each isolation barrel. 3) Use the device to conduct coarse aggregate segregation test, and calculate the index of coarse aggregate segregation degree. 4) Establish the index model equation of segregation degree through regression analysis. 5) Estimate the segregation degree of asphalt mixture by using the model equation and design gradation information. The technical principle of the invention is clear, the device is easy to manufacture, the test and calculation process is simple, and the estimation method is reliable.

Description

Method and device for estimating segregation degree of asphalt mixture

technical field

The invention belongs to the technical field of asphalt pavement materials, and in particular relates to an evaluation index of coarse aggregate segregation degree, a coarse aggregate segregation test device, and a method for estimating the segregation degree of asphalt mixture.

Background technique

Asphalt mixture segregation refers to the uneven distribution of coarse aggregate and fine aggregate with different particle sizes in the aggregate, which seriously affects the road performance of asphalt pavement. In view of this, relevant research on asphalt mixture segregation has been carried out at home and abroad. At present, there are mainly two types of commonly used evaluation methods for asphalt mixture segregation at home and abroad. One is to directly evaluate asphalt mixture segregation, which mainly includes visual inspection method, structural depth method, in-situ density method, gradation analysis method, and water seepage test. method, infrared thermal imager method, image analysis method, etc. CN103196813 B authorizes a detection method for the degree of segregation of asphalt mixture on the road surface, the invention judges the degree of segregation based on the correlation between the penetration time of the asphalt mixture rut specimen and the void ratio, and the detection method is based on the asphalt mixture rut specimen Water penetration test. The preparation of the test piece and the test process involved in this method are cumbersome, and it is an indirect judgment method with many error factors. CN104251805 A discloses a rapid detection method and equipment for asphalt mixture gradation. The method uses asphalt mixture as a test object, and selects a gradation rough ratio index and a gradation stability coefficient to evaluate the quality of the aggregate ratio. Because the test temperature significantly affects the construction workability and segregation degree of asphalt mixture, and the test equipment has no relevant temperature control device, the accuracy of the test results and evaluation indicators is difficult to control. The other is to directly study the segregation of aggregates, and evaluate the segregation degree of asphalt mixture according to the segregation of aggregates. CN105259338 A discloses segregation performance evaluation equipment and evaluation methods for road granular base materials. The invention uses the ratio of the pile diameter to the pile height as the segregation index, which is based on the positive correlation between the segregation degree and the pile angle. . However, there are many factors that affect the accumulation angle. For example, fine materials generally have a large angle of repose. If only a single particle size is used, there will be no segregation at this time. However, if this index is used, the segregation degree of fine materials will be smaller than that of coarse materials. , it is not as accurate and intuitive as directly using the results reflected by aggregate gradation differences. In addition, the above inventions are for testing segregation after the asphalt mixture design is completed, and cannot be used in the gradation design stage, so they cannot directly guide the gradation optimization design.

Contents of the invention

The first object of the present invention is to provide an evaluation index of coarse aggregate segregation degree, which is obtained by simulating the segregation of coarse aggregate during unloading from a silo.

The second object of the present invention is to provide a test device for simulating the distribution of coarse aggregate in each area during the process of the falling of coarse aggregate and the formation of stockpile, and use the device to analyze and calculate the evaluation index of segregation degree of coarse aggregate through experiments. The device is designed according to the law of particle movement, and the isolation buckets are set up layer by layer, which is convenient for taking materials from different areas of the stockpile and performing gradation analysis.

The third object of the present invention is to provide a method for estimating the segregation degree of asphalt mixture, which is based on the theoretical basis that the segregation of asphalt mixture and the segregation of coarse aggregate are positively correlated.

In order to achieve the above object, the first technical solution provided by the present invention:

Based on the technical principle of the distribution difference of aggregates with different particle sizes in the process of free falling to form stockpiles, an evaluation index for the degree of segregation of coarse aggregates is proposed. Obtained from segregation during silo discharge. Divide the stockpile into n areas from the inside to the outside in the form of concentric circles, 3≤n≤6, take the coarse aggregate in each area for screening test, obtain the coarse aggregate grading curve in each area, and analyze The deviation between the coarse aggregate gradation curve in each region and the coarse aggregate gradation curve before falling (that is, the original gradation), that is, by calculating the area enclosed by these two gradation curves, the coarse aggregate in each region can be obtained. Degree of segregation. Using this calculation method, the segregation degree index ΔSD _i (i=1,2,...,n) of each region can be obtained, and then the weighted average can be obtained by taking the ratio of coarse aggregate in each region to the total mass of the stockpile as the weight Coarse aggregate segregation degree index SD, the calculation result is expressed as a percentage, and the calculation formula is as follows:

In the formula: i=1,2,...,n is the area number, representing n areas from the inside to the outside, 3≤n≤6; k _i is the weight, which means that the mass of coarse aggregate m _i in each area accounts for the total The ratio of mass m; ΔSD _i is the area surrounded by the coarse aggregate gradation curve and the original gradation curve in region i; The aggregate sieves of 16mm, 19mm, 26.5mm, and 31.5mm are recorded as 1, 2, 3, 4, 5, 6, 7, and 8 sieves from small to large; c _j represents the sieve hole diameter corresponding to each serial number sieve ; Respectively, the passing rate of the actual grading curve and the original grading curve of the coarse aggregate in area i at the j sieve hole.

The second scheme provided by the present invention is:

The test device used to analyze the degree of segregation of coarse aggregate, including:

The bracket, the funnel is fixed on the bracket, and the funnel is used to hold the coarse aggregate mixed according to the gradation ratio. Below, and the distance between the receiving tray and the funnel is set;

Several isolation barrels with different inner diameters are concentrically arranged. When the material receiving tray is lowered, the isolation barrels rise and pass through the material receiving tray, and the coarse aggregate falling on the material receiving tray enters the isolation barrel.

In order to simplify the structure, the bracket can be two vertical rods, the funnel is set horizontally and fixed on the upper part of the bracket through the funnel frame, the two sides of the funnel frame are set through the two vertical rods, and the two sides of the funnel frame are respectively fixed to the bracket by fixing knobs with funnel rack.

In order to facilitate the analysis of the segregation degree of the coarse aggregate, the bottom of the funnel is set 110-130 cm higher than the supporting plate.

In order to keep the shape of the pile of coarse aggregate on the material receiving tray and prevent the loss of coarse aggregate particles, an annular material receiving blocking bucket is set on the material receiving tray.

The receiving tray is provided with a number of upper and lower connected circles and a circle of grooves for fixing the receiving bucket, the bottom of the receiving tray is provided with cross steel bars to fix the receiving tray, and the side wall of each of the isolation barrels It is divided into four sections to facilitate the passage of cross bars, and the size of the circle matches the size of the isolation barrel.

The isolation barrel includes the side wall and a support plate fixed on the bottom of the bracket. The upper surface of the support plate is provided with a groove for fixing the side wall, so as to facilitate the removal of the side wall of the isolation barrel in the later stage, so that it can be removed from a certain Coarse aggregate is taken out of an isolation barrel.

In order to divide the stockpile into n areas, the isolation barrels are provided with n-1 layers in total, and their inner diameters are dcm, 2d cm, ..., (n-1)d cm from the inside to the outside. The inner diameter is nd cm, where 3≤n≤6, 10≤d≤20, 45≤nd≤80.

The circumference of the support disc is set beyond the bracket.

The receiving tray is provided with an opening, the bracket is set through the opening, and a lifting mechanism is set between the support tray and the receiving tray. When the receiving tray is at the highest position, the highest position of the isolation barrel is in contact with The upper surface of the receiving tray is flush.

Further, the lifting mechanism is arranged on the outer ring of the bracket.

The test method for obtaining the index of coarse aggregate segregation degree by using the test device is as follows:

1) The coarse aggregate mixed according to the gradation ratio falls freely from the set height to form a pile in the receiving tray;

2) The material receiving tray moves downward under the drive of the lifting mechanism, and several concentric isolation barrels move up through the material receiving tray, and the coarse aggregate on the material receiving tray falls into the isolation barrel;

3) Retrieving and screening the coarse aggregate in the isolation barrel layer by layer from the outside to the inside to obtain the coarse aggregate gradation curve in each isolation barrel;

4) Obtain the segregation degree index SD by calculating the weighted average value of coarse aggregate gradation deviation in each region;

5) Repeat step 1)-step 4) at least 3 times, and the average value obtained is used as the final test result.

The third scheme provided by the present invention is:

A method for estimating the degree of segregation of asphalt mixture, the method is based on the theory that the segregation of asphalt mixture and the segregation of coarse aggregate are positively correlated, adopts the uniform design method of mixture design to design the test plan, through the segregation provided by the present invention The evaluation index, test device and test method determine the segregation degree index of each group of coarse aggregate in the test plan, and perform regression analysis on the test results of each group to obtain a prediction model. The specific steps are as follows:

1) According to the nominal maximum particle size of the asphalt mixture, determine the grade number a of the coarse aggregate (particle size ≥ 2.36mm) (for example, a=5 when AC-16 is graded), and the ratio of each grade of coarse aggregate to the total mass is the independent variable, and the segregation degree index SD is the dependent variable. The uniform mixture design method is used for experimental design, and the experimental plan is formulated. Since the sum of the proportions of each grade of coarse aggregate to the total mass is 100%, the number of test factors is a-1, and the number of groups of the test scheme is (a-1) ² .

2) According to the above-mentioned test scheme, the segregation degree index of each group of coarse aggregate in the test scheme is determined through the coarse aggregate segregation evaluation index, test device and test method provided by the present invention.

3) According to the above test results, a regression model equation with the ratio of coarse aggregate to the total mass of each grade as the independent variable and the segregation degree index as the dependent variable was established by statistical software, and the obtained equation and regression coefficient were tested for significance.

4) If the above significance test meets the requirements, the established regression equation is valid and can be used as a formula for estimating the segregation degree of asphalt mixture; if it does not meet the requirements, repeat steps 1)-3) until the test meets the requirements .

5) When designing asphalt mixture gradation, substituting the proportions of coarse aggregates of different design gradations into the above model equations can estimate their segregation degree, so that the segregation degree is small and the mineral void ratio meets the specification requirements. As the design gradation, the gradation provides a theoretical basis and feasible method for gradation optimization design.

The present invention has the following advantages:

1) The technical principle of the present invention is clear and definite, the meaning of the evaluation index is clear, and the calculation is relatively simple.

2) The overall structure of the test device of the present invention is simple. Through the setting of the lifting mechanism, the receiving tray and the isolation barrel, it is convenient to collect the aggregates in each area of the aggregate stockpile, and the segregation of the aggregates in each area can be obtained quickly, and then determined. Segregation degree index.

3) The test object of the present invention is coarse aggregate instead of asphalt mixture, the method is simple to operate, and the segregation degree prediction model equation can be established through a small amount of tests and calculations, which can be used to estimate the segregation of asphalt mixture in the gradation design stage The degree provides a theoretical basis and a feasible method for the gradation optimization design.

Description of drawings

Fig. 1 is the overall schematic diagram of the coarse aggregate segregation degree evaluation device;

Fig. 2 is a schematic diagram of an isolation barrel isolation stockpile;

Fig. 3 is the structural representation of the funnel frame connecting the funnel and the support;

Fig. 4 is the structural diagram of receiving tray;

Fig. 5 is a structural schematic diagram of several isolation barrels fixed on the support plate through grooves;

In the figure: 1- funnel; 2- rotating baffle; 3- funnel frame; 4- fixed knob; 5- bracket; 6- lifting mechanism; 10 - Isolation barrel.

detailed description

The following will systematically describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

The test device used to analyze the degree of segregation of coarse aggregate, as shown in Figure 1 and Figure 2, includes:

The bracket, the funnel 1 is fixed on the bracket, and the funnel is used to hold the coarse aggregate mixed according to the gradation ratio. The baffle plate 2 closes the bottom of the funnel. After the rotating baffle plate 2 is opened, the coarse aggregate falls into the receiving tray 8 through the funnel 1. The receiving tray can be lifted and lowered under the funnel 1. The bottom of the funnel is higher than the support tray 9 110cm setting, and the distance setting between the material receiving tray and the funnel is set.

Three concentric isolation barrels 10 with different inner diameters have inner diameters of 18cm, 36cm, and 54cm from inside to outside. When the material receiving tray 8 descends, the isolation barrel 10 rises and passes through the material receiving tray 8, and the coarse aggregate falling on the material receiving tray 8 enters in the isolation barrel 10.

For simplifying the structure, the support 5 can be two vertical rods, the funnel 1 is horizontally arranged and fixed on the top of the support 5 by the funnel frame 3, the two sides of the funnel frame 3 pass through the two vertical rods, and the two sides of the funnel frame 3 The bracket and the funnel frame are respectively fixed by the fixing knob 4, so that the height of the funnel is adjustable.

An annular material receiving block bucket 7 is set on the material receiving tray 8, and the inner diameter is 72cm.

The material receiving tray 8 is provided with three up and down connected circles, which are used for the passage of the isolation barrel 10; The cross steel bar is set to fix the receiving tray, and the side wall of each of the isolation buckets 10 is divided into four sections so that the cross steel bars pass through, and the size of the ring matches the size of the isolation bucket 10.

The isolation barrel 10 includes the side wall and the support plate 9 fixed on the bottom of the bracket, as shown in Figure 5, the upper surface of the support plate 9 is provided with a groove for fixing the side wall, so as to facilitate the later stage of the isolation barrel 10 side walls are removed to facilitate the removal of the aggregate in a certain isolation bucket 10.

The circumference of the support plate 9 is set beyond the support 5; the receiving tray 8 is provided with an opening, and the support 5 is arranged through the opening, between the support plate 9 and the receiving tray 8 Lifting mechanism 6 is arranged between, and described lifting mechanism 6 is located at the outer ring of described support 5, and lifting mechanism can be electric lifter, and when material receiving tray 9 is at the highest position, the highest position of isolation barrel 10 and the upper surface of material receiving tray flush.

Due to the different sizes of the particles, their movement distances in the process of free falling to form a stockpile will be different. The larger the particle size, the farther the movement distance, which leads to the gradation of the stockpile from the inside to the outside. Circumstances change, resulting in segregation. Based on this, the stockpile is divided into four areas from the inside to the outside in the form of concentric circles, and the deviation between the coarse aggregate grading curve of each area and the original grading curve is analyzed, that is, by calculating the two grading curves The area surrounded by the curve can obtain the segregation of coarse aggregate in each region. Using this calculation method, the segregation index ΔS _i (i=1, 2, 3, 4) of the four regions can be obtained, and then the final segregation can be obtained by weighting the ratio of coarse aggregate to the total mass of the stockpile in each region as the weight The degree index SD, the calculation result is expressed as a percentage, and the specific calculation formula is as follows:

In the formula: i=1, 2, 3, 4 are area numbers, which represent four areas from inside to outside; k _i is weight, which refers to the proportion of the mass of coarse aggregate in each area to the total mass; ΔSD _i is the coarse aggregate in area i The area enclosed by the aggregate gradation curve and the original gradation curve; j is the serial number of the aggregate sieve, that is, the aggregate sieve diameters are 2.36mm, 4.75mm, 9.5mm, 13.2mm, 16mm, 19mm, 26.5mm, and 31.5mm. The material sieves are recorded as No. 1, 2, 3, 4, 5, 6, 7, and No. 8 sieves from small to large; c _j represents the sieve hole diameter corresponding to each serial number sieve; Respectively, the passing rate of the actual grading curve and the original grading curve of the coarse aggregate in area i at the j sieve hole.

Using the above-mentioned device, the specific test method is as follows:

1) The coarse aggregates of each grade are batched according to the gradation ratio, and the mass of the sample is 10-15kg or more;

2) The coarse aggregate is fully mixed evenly by multiple times of overturning and stirring, and then the mixed coarse aggregate is loaded into the funnel 1 twice;

3) Fix the funnel frame 3 on the bracket 5 at a distance of 110-130cm from the support plate;

4) Put the funnel 1 filled with material on the bracket 5 and ensure that the funnel 1 is in a horizontal state, and rotate the baffle plate 2 at the mouth of the funnel to make the coarse aggregate fall freely and form a pile on the receiving tray 8;

5) Slowly lower the material receiving tray 8 along the support through the lifting mechanism 6, so that the material pile is isolated into four parts when passing through the isolation barrel 10;

6) Remove the side wall of the isolation barrel layer by layer from the outside to the inside to take the material and carry out the screening test to obtain the gradation curve of the coarse aggregate in each area;

7) Use the formula to calculate the segregation degree index SD, repeat the above test at least three times, and obtain the average value as the final result obtained from the test.

Taking the ratio of the mass of each grade of coarse aggregate to the total mass in the gradation as the independent variable, and the segregation index SD as the dependent variable, a quadratic multivariate nonlinear equation was used to perform regression analysis on the test data, in which the number of independent variables was the same as that of the asphalt mixture The nominal maximum particle size is related. Taking AC-16 as an example, there are five grades of coarse aggregate: 2.36-4.75mm, 4.75-9.5mm, 9.5-13.2mm, 13.2-16mm, and 16-19mm, so there are 5 dependent variables, which are set as X ₁ and X ₂ , X ₃ , X ₄ and X ₅ are the proportions of each grade of coarse aggregate to the total mass, respectively. The test plan was formulated by using the mixed material uniform design method, and the segregation degree index SD of each group was obtained through the above test steps and calculations. The results are shown in Table 1.

Table 1 Coarse aggregate ratio and segregation test results of each group of AC-16

Using the test results in Table 1, a multivariate statistical regression model was established using software such as Matlab, SPSS, DPS, and Mathematica, and the regression equation was obtained as follows:

SD(x)＝6.57807+0.23754x ₂ +0.36526x ₅ -0.0033792x ₂ ² -0.0020741x ₃ ² -0.00161631x ₄ ²

-0.00624091x ₅ ² -0.00524766x ₂ x ₃ -0.00172642x ₂ x ₄ -0.00460765x ₂ x ₅ +0.00310281x ₃ x ₄

+0.00126779x ₃ x ₅ -0.00528102x ₄ x ₅

In order to test the reliability of the regression model equation, the F test is carried out on the equation at the significance level α. If F≥F _α (m,nm-1), the regression model equation is significant at the given significance level α , otherwise it is not significant; at the same time, the significance of the regression coefficient still needs to be tested, if F _i ≥ F _α (1,nm-1), it is significant, otherwise it is not significant. In this model equation, the significance level is α=0.05, the number of independent variables is m=12, and the number of observation groups is n=16. After checking the F distribution table: F _α (m,nm-1)=F _0.05 (12, 3) = 8.74, F _α (1, nm-1) = F _0.05 (1, 3) = 10.13. The F value of the regression equation calculated by the statistical software is 556.20, greater than 8.74; the F _i values of the significance test of each coefficient are shown in Table 2, all greater than 10.13. Therefore, both the regression equation and the regression coefficient are significant at the significance level α=0.05, indicating that the equation is valid at this significance level.

Table 2 Model Significance Test Results

coefficient term Significance test of coefficient F _i value _x2 50.11 _x5 247.3 X ₂ ² 87.13 X ₃ ² 253.45 X ₄ ² 285.24 X ₅ ² 320.06 X ₂ X ₃ 65.11 X ₂ X ₄ 60.9 X ₂ X ₅ 132.1 X ₃ X ₄ 78.2 X ₃ X ₅ 19.73 X ₄ X ₅ 944.44

At the same time, in order to ensure the prediction accuracy of the regression model, the prediction results of the model were compared with the actual test results. The results are shown in Table 3, and the average relative error is 0.8%.

Table 3 Analysis results of model prediction accuracy

Through the significance test of the regression model coefficient and the analysis of the model prediction accuracy, the regression model equation meets the requirements and is relatively reliable.

In order to illustrate the application and verification of the regression model equation, three gradation curves were selected within the engineering gradation range stipulated in JTG F40-2004 "Technical Specifications for Construction of Highway Asphalt Pavement". The obtained segregation degree index SD (actual measurement) is listed in Table 4, and the predicted value SD' (prediction) of the segregation degree index can be obtained by substituting the proportions of the three groups into the model equation established above, which is also listed in Table 4. It can be seen from the SD (actual measurement) and value SD' (prediction) in Table 4 that although there is a certain deviation between the predicted value and the measured value, their order of size is consistent, all of which are group 1<group 3<group 2, indicating the level The degree of segregation was the least for configuration 1. Therefore, the segregation degree of asphalt mixture can be predicted according to the model equation established by the coarse aggregate segregation test.

Table 4 The test value and predicted value of the three graded coarse aggregate ratio and segregation degree

At present, there is no systematic asphalt mixture segregation evaluation system in our country, and most of the existing segregation evaluation indexes need to test and evaluate the asphalt mixture or asphalt mixture specimens. Compared with the practice of sorting the degree of segregation that must go through tedious tests, the method proposed by the present invention has obvious technical advantages. First, the technical principle is clear and definite, the meaning of the evaluation index is clear, and the calculation is relatively simple; It is simple, the test process is simple and feasible, and the amount of test and calculation is relatively small; third, the segregation degree of asphalt mixture can be predicted in the stage of gradation design, which provides a theoretical basis and feasible method for gradation optimization design.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Parts presented in detail and partially enlarged are prior art, and will not be repeated here. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and characteristics disclosed herein.

Claims (10)

1. A coarse aggregate segregation degree evaluation index is characterized in that, the coarse aggregate mixed in proportion is carried out free fall to form a stockpile, and the stockpile is divided into n areas from the center to the outside, 3≤n≤6, A coarse aggregate segregation degree evaluation index SD is obtained by the weighted average of the coarse aggregate gradation deviation in each area of the stockpile, where the gradation deviation value is determined by the area enclosed by the coarse aggregate gradation curve and the original gradation curve express. 2. a kind of rough set segregation degree evaluation index as claimed in claim 1, is characterized in that, segregation degree evaluation index SD calculates according to following formula: $\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 4</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{\mathrm{<span\; class="notranslate">\; k</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;\; SD</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$ ${\mathrm{<span\; class="notranslate">\; k</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; m</span>}}$ ${\mathrm{<span\; class="notranslate">\; \&Delta;SD</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\underset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 8</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}<span\; class="notranslate">\; (</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{{\mathrm{<span\; class="notranslate">\; ic</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; p</span>}}_{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{{\mathrm{<span\; class="notranslate">\; ic</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; p</span>}}_{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}^{\mathrm{<span\; class="notranslate">\; 0.45</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 0.45</span>}}<span\; class="notranslate">\; )</span>$ In the formula: i=1,2,...,n is the area number, representing n areas from the inside to the outside, 3≤n≤6; k _i is the weight, which means that the mass of coarse aggregate in each area accounts for the total mass Ratio; ΔSD _i is the area enclosed by the coarse aggregate gradation curve in area i and the original gradation curve; j is the aggregate sieve number, that is, the sieve hole diameters are 2.36mm, 4.75mm, 9.5mm, 13.2mm, 16mm, 19mm , 26.5mm, and 31.5mm aggregate sieves are recorded as No. 1, 2, 3, 4, 5, 6, 7, and No. 8 sieves from small to large; c _j represents the sieve hole diameter corresponding to each serial number sieve; Respectively, the passing rate of the actual grading curve and the original grading curve of the coarse aggregate in area i at the j sieve hole. 3. the acquisition method of a kind of coarse aggregate segregation evaluation index as described in any one in claim 1-2, it is characterized in that, concrete steps are as follows: 1) Drop the coarse aggregate mixed according to the gradation ratio from the set height to form a pile in the receiving tray; 2) The material receiving tray moves downward under the drive of the lifting mechanism, and several concentric isolation barrels move up through the material receiving tray, and the coarse aggregate on the material receiving tray falls into the isolation barrel; 3) Retrieving and screening the coarse aggregate in the isolation barrel layer by layer from the outside to the inside to obtain the coarse aggregate gradation in each isolation barrel; 4) The segregation degree index SD is obtained by the weighted average of the coarse aggregate gradation deviation in each region; 5) Repeat step 1)-step 4) at least 3 times, and obtain the average value as the test result. 4. A test device for analyzing the degree of segregation of coarse aggregate, characterized in that it includes: The bracket, the funnel is fixed on the bracket, and the funnel is used to hold the coarse aggregate mixed according to the gradation ratio. Below, and the distance between the receiving tray and the funnel is set; Several isolation barrels with different inner diameters are concentrically arranged. When the material receiving tray is lowered, the isolation barrels rise and pass through the material receiving tray, and the coarse aggregate falling on the material receiving tray enters the isolation barrel. 5 . The device for analyzing the degree of segregation of coarse aggregate according to claim 4 , wherein the bottom of the funnel is set 110-130 cm higher than the support plate. 6 . The device for analyzing the degree of segregation of coarse aggregate as claimed in claim 4 , wherein an annular material receiving bucket is arranged on the material receiving tray. 7 . 7. The device for analyzing the degree of segregation of coarse aggregates as claimed in claim, wherein the receiving plate is provided with a plurality of upper and lower connected circles and a circle of grooves for fixing the receiving bucket The bottom of the tray is provided with cross bars to fix the tray, and the side wall of each isolation barrel is divided into four sections to facilitate the passage of the cross bars. 8. The device for analyzing the degree of segregation of coarse aggregate as claimed in claim 4, wherein the isolation barrel includes the side wall and a support plate fixed on the bottom of the support, and the upper surface of the support plate is Provide grooves for fixing side walls; Further, the circumference of the support disc is set beyond the bracket; Further, the receiving tray is provided with an opening, the bracket is set through the opening, and a lifting mechanism is provided between the supporting tray and the receiving tray; Further, the lifting mechanism is arranged on the outer ring of the bracket. 9. A method for analyzing and estimating the segregation degree of asphalt mixture, characterized in that, the specific steps are as follows: 1) For the nominal maximum particle size of different asphalt mixtures, the number of groups of the test scheme is determined by the uniform mixture design method, and the segregation degree index SD of each group is obtained by the method described in claim 3; 2) Establishing a multivariate statistical regression model equation for the data obtained in step 1), and carrying out a significance test to the obtained equation and regression coefficient; 3) If the inspection meets the requirements, the regression equation is valid and can be used as a formula for estimating the segregation degree of asphalt mixture; if the inspection does not meet the requirements, repeat steps 1)-2) until the inspection is qualified. 10. a kind of method for estimating asphalt mixture segregation degree size as claimed in claim 9, it is characterized in that, in described step 2) utilize software such as Matlab, SPSS, DPS, Mathematica to step 1) The data obtained were used to establish a multivariate statistical regression model.