Microcosmic multiphase evaluation method for rubber-plastic composite modified asphalt

Abstract

The invention provides a microscopic multiphase evaluation method for rubber-plastic composite modified asphalt. The microscopic multiphase evaluation method comprises the following steps: heating the rubber-plastic composite modified asphalt to a flowing state; selecting an improved glass slide; fully flowing rubber and plastic composite modified asphalt is poured into a groove of the improved glass slide; heating the loaded glass slide until the sample fully and uniformly flows, and lightly scraping out the asphalt outside the groove area by using a heated scraper; observing the sample by using a fluorescence microscope, uniformly taking nine observation points in the range of the sample groove, and storing images; image processing software is adopted to calculate and obtain evaluation indexes of nine images so as to evaluate the distribution condition and characteristics of the rubber powder and polyethylene composite phase in the rubber and plastic asphalt. The rubber and plastic composite modified asphalt microcosmic multiphase evaluation method is beneficial for judging the development process of asphalt modification and the dispersion state of the modifier in asphalt, and supports optimization of asphalt modification processes and materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road materials, in particular to a rubber-plastic composite modified asphalt micro-multiphase state evaluation method. BACKGROUND

[0002] Due to the need for a large amount of agricultural land in the development process of the city, the soil and water body are continuously reduced, and the hardened urban surface is replaced. The impermeable ground makes the city drainage rely on the underground pipe network during rainfall. When the rainfall is too large, it cannot meet the drainage demand and causes waterlogging and even floods. The sponge city uses the functions of water permeability, water absorption and drainage to realize the buffering effect of rainwater. For some low-lying areas, only relying on drainage pavement cannot completely solve the problem of waterlogging and flooding, so the underground water storage tank is used in the public plot of the city to buffer rain and flood, but the water storage device in the existing patent contains a large number of filtering structures to hinder the flow of rainwater, and cannot fully play the role of storing rainwater in heavy rain and the like. The water storage device of the present application can meet the need of purifying rainwater in light rain and realize the function of rapid water storage in heavy rain. SUMMARY

[0003] The purpose of the present application is to provide a rubber-plastic composite modified asphalt micro-multiphase state evaluation method, which overcomes the subjectivity and variability of fluorescence microscope analysis of phase state characteristics, improves the quantitative evaluation method of rubber-plastic asphalt phase state, and proposes a phase state evaluation index for rubber-plastic asphalt, which has certain guiding significance for studying the microstructure change of rubber-plastic asphalt and the optimization design of rubber-plastic asphalt modification.

[0004] To achieve the above purpose, the present application provides a rubber-plastic composite modified asphalt micro-multiphase state evaluation method, comprising the following steps: S1, heating the rubber-plastic composite modified asphalt to a flow state; S2, selecting an improved glass slide with a sample loading groove; S3, pouring the rubber-plastic composite modified asphalt in a flow state into the groove of the glass slide selected in step S2, and uniformly covering the groove with the asphalt sample; S4, heating the glass slide containing the rubber-plastic composite modified asphalt until the rubber-plastic composite modified asphalt in the glass slide is fully flowed and uniformly, and then using a heated scraper to gently scrape out the asphalt outside the groove area; S5, observing the sample using a fluorescence microscope and saving images at multiple observation points in the sample groove range; S6, calculating the fluorescence phase area average value, the long-short axis ratio average value and the circularity index of multiple images using image processing software to evaluate the distribution and characteristics of the rubber-plastic composite phase in the rubber-plastic asphalt.

[0005] Preferably, the temperature at which the rubber-plastic composite modified asphalt is heated to a fluid state is 160°C.

[0006] Preferably, the dimensions of the groove in the glass slide are 20mm × 20mm × 0.5mm.

[0007] Preferably, the locations of multiple observation points are obtained in a nine-square grid pattern.

[0008] Preferably, the ratio of major to minor axis refers to the ratio of the length of the major axis to the length of the minor axis within the fluorescent phase region, including the average ratio of major to minor axis and the difference in the ratio of major to minor axis. The calculation method is as follows: ; ; ; in, L This refers to the ratio of the major and minor axes of a single fluorescent phase particle. D l The length of the major axis of the ellipse fitted to the fluorescent phase particles. D s The length of the minor axis of the ellipse fitted to the fluorescent phase particles. L a This is the arithmetic mean of the ratios of the major and minor axes of multiple observation points. L i For the first i The ratio of the major and minor axes of an observed image or particle; n is the total number of observation points or identified particles. L d The index representing the difference in the ratio of the major and minor axes. This represents the ratio of the major and minor axes.

[0009] Preferably, the roundness index R is a shape feature used to evaluate the similarity between a graphic and a circle. The smaller the roundness, the greater the difference between the particle and the circle. Its calculation method is as follows: ; P is the perimeter, and A is the area.

[0010] Therefore, the present invention adopts the above-mentioned microscopic multiphase evaluation method for rubber-plastic composite modified asphalt. The proposed area and shape characteristic indicators can avoid the subjectivity of observation and fully reflect the distribution and shape law of multiphase composite modified asphalt. It can more intuitively analyze the distribution and changes of rubber-plastic modifiers in asphalt, which helps to judge the development process of asphalt modification and the dispersion state of modifiers in asphalt, and supports the optimization of asphalt modification process and materials. Attached Figure Description

[0011] Figure 1 The selection method for the 9 observation points; Figure 2To improve the slide diagram; Figure 2 (a) is a top view of the improved slide; Figure 2 (a) is a side view of the improved slide; Figure 3 To image fluorescence region processing diagram; Figure 3 (a) is a schematic diagram of image batch uploading processing; Figure 3 (b) is a schematic diagram of image fluorescence region identification and extraction; Figure 3 (c) is a schematic diagram of fluorescence region shape index extraction. DETAILED DESCRIPTION

[0012] The technical solutions of the present application are further described below through the drawings and examples.

[0013] Unless otherwise defined, the technical terms or scientific terms used in the present application shall be understood as the usual meaning understood by those skilled in the art to which the present application belongs.

[0014] Example one A micro-multiphase state evaluation method for rubber-plastic composite modified asphalt, comprising the following steps: S1, placing rubber-plastic composite modified asphalt in a 160℃ oven to a fully flowing state; S2, selecting an improved slide with a sample loading groove, the improved slide has a 20mm×20mm×0.5mm groove at one end, as shown in Figure 2 ; S3, pouring the fully flowing rubber-plastic composite modified asphalt into the groove of the improved slide, so that the asphalt sample is uniformly covered, without covering the cover glass; S4, after heating the loaded slide to a fully flowing and uniform state of the sample, using a heated scraper to gently scrape off the asphalt outside the groove area; S5, using a fluorescence microscope to observe the sample, saving images at 9 evenly spaced observation points within the sample groove range, the 9 evenly spaced observation points are arranged in a nine-square grid, and the method of taking observation point images each time is consistent, as shown in Figure 1 and Figure 3 ; S6, using image processing software to calculate the average value of the fluorescence phase area, the average value of the ratio of the long axis to the short axis, and the circularity index of the 9 images, to evaluate the distribution and characteristics of the rubber powder and polyethylene composite phase in the rubber-plastic asphalt.

[0015] Further, the ratio of the long axis to the short axis in step S6 refers to the ratio of the length of the long axis to the length of the short axis in the fluorescence phase area.

[0016] Further, the circularity of step S6 refers to a shape feature for evaluating the similarity of a figure to a circle, and the smaller the circularity, the greater the difference between the particle and the circle.

[0017] Placing the rubber-plastic composite modified asphalt No. 1 and No. 2 in a 160℃ oven to heat to a fully flowing state. Pouring the fully flowing rubber-plastic composite modified asphalt into the groove of the improved glass slide, so that the asphalt sample is uniformly covered, and no cover glass is added. After heating the loaded glass slide to a fully flowing and uniform state of the sample, use a heated spatula to gently scrape off the asphalt outside the groove area. Using a fluorescence microscope to observe the sample, saving the images of 9 evenly observed points in the sample groove range, the acquisition positions of the 9 evenly observed points are a nine-square grid, and the method of taking the observed point images each time is consistent. The Imagepro image processing software is used to calculate the average value of the fluorescence phase area, the average value of the long and short axis ratio and the circularity index of 9 images, and the results are shown in Table 1.

[0018] Table 1 Image processing result table

[0019] Table 2 Microscopic evaluation index of sample No. 1

[0020] Therefore, the above-mentioned rubber-plastic composite modified asphalt microscopic multi-phase evaluation method can help to judge the development process of asphalt modification and the dispersion state of the modifier in the asphalt, and support the optimization of the asphalt modification process and materials.

[0021] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application but not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: it can still modify or equivalently replace the technical solutions of the present application, and these modifications or equivalent replacements also cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for evaluating the micro-multiphase state of a rubber-plastic composite modified asphalt, characterized in that, The method comprises the following steps: S1, heating the rubber-plastic composite modified asphalt to a flow state; S2, selecting a glass slide with a sample groove; S3, pouring the rubber-plastic composite modified asphalt in a flow state into the groove of the glass slide selected in step S2, and uniformly covering the groove with the asphalt sample; S4, heating the glass slide with the rubber-plastic composite modified asphalt until the rubber-plastic composite modified asphalt in the glass slide fully flows and is in a uniform state, and then using a heated scraper to gently scrape off the asphalt outside the groove area; S5, observing the sample using a fluorescence microscope, uniformly taking multiple observation points in the groove range of the sample, and saving images; S6, calculating the fluorescence phase area average value, the long-short axis ratio average value, and the circularity index of multiple images using image processing software to evaluate the distribution and characteristics of the rubber powder and polyethylene composite phase in the rubber-plastic asphalt.

2. The method for evaluating the micro-heterogeneous state of rubber-plastic composite modified asphalt according to claim 1, characterized in that, The temperature at which the rubber-plastic composite modified asphalt is heated to a flow state is 160 DEG C.

3. The method for evaluating the micro-heterogeneous state of a rubber-plastic composite modified asphalt according to claim 1, characterized in that, The size of the groove of the glass slide is 20mm x 20mm x 0.5mm.

4. The method for evaluating the micro-heterogeneous state of rubber-plastic composite modified asphalt according to claim 1, characterized in that, The positions of the multiple observation points are in a nine-square grid type.

5. The method for evaluating the micro-heterogeneous state of a rubber-plastic composite modified asphalt according to claim 1, characterized in that, The long-short axis ratio refers to the ratio of the long axis length to the short axis length in the fluorescence phase area, including the long-short axis ratio average value and the long-short axis ratio difference value, and the calculation method is as follows: ； ； ； in, L This refers to the ratio of the major and minor axes of a single fluorescent phase particle. D l The length of the major axis of the ellipse fitted to the fluorescent phase particles. D s The length of the minor axis of the ellipse fitted to the fluorescent phase particles. L a This is the arithmetic mean of the ratios of the major and minor axes of multiple observation points. L i For the first i The ratio of the major and minor axes of an observed image or particle; n is the total number of observation points or identified particles. L d The index representing the difference in the ratio of the major and minor axes. This represents the ratio of the major and minor axes.

6. The method for evaluating the micro-heterogeneous state of a rubber-plastic composite modified asphalt according to claim 1, characterized in that, The circularity index R is a shape feature for evaluating the similarity between a graph and a circle, and the smaller the circularity, the greater the difference between the particle and the circle, and the calculation method is as follows: ； P is the circumference, and A is the area.

Images