Method for evaluating asphalt mixture aggregate distribution state

Abstract

The invention discloses a method for evaluating asphalt mixture aggregate distribution state, and the method comprises the following steps: firstly acquiring cross section image of on-site core sample or indoor moulding cylindrical test piece using industrial CT machine or digital camera, and converting images into black white images with BMP format; obtaining information of each aggregate particle in the asphalt mixture section image from the black white image; quantitatively evaluating the mixture aggregate distribution state in the three aspects of position distribution, quantity distribution and long axis azimuth of each aggregate in the mixture; representing the mixture aggregate distribution state on the direction using the mixture aggregate distribution state on a set parallel cross sections, and finally, quantitatively evaluating the asphalt mixture aggregate distribution state using the distribution state on the horizontal direction and vertical direction of the aggregates. The smaller total evaluate index of the aggregate distribution state, the better distribution state of the corresponding asphalt mixture aggregates; conversely, the worse distribution state of the asphalt mixture aggregates.

Description

technical field [0001] The invention belongs to the field of road engineering and relates to a method for quantitatively evaluating the distribution state or uniformity of asphalt mixture aggregates. Background technique [0002] The composition of asphalt mixture includes four parts: asphalt, aggregate, additive and void, among which aggregate has the greatest influence on the performance of asphalt mixture. The physical properties of the aggregate (shape, size, angle, flatness, surface texture, etc.), gradation, and distribution in the asphalt mixture (position, quantity, spacing, azimuth, etc.), all have a great impact on the asphalt mixture. Mechanical properties, road performance indicators and fatigue life have a significant impact. Among the many factors affecting the performance of asphalt mixture, the distribution state of aggregate is the most prominent and the most complicated. To some extent, the distribution state of aggregate determines the performance of asp...

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Problems solved by technology

[0003] However, the existing literature shows that there are few studies on the influence of aggregate distribution state on the performance of asphalt mixture.

Analyzing the above phenomena, the main reasons are as follows: (1) The influence of the aggregate distribution state on the performance of asphalt mixture is ignored, and people have not given enough understanding to the importance of the aggregate distribution state of asphalt mixture

(2) The distribution state of aggregates in asphalt mixture is very complicated. Through traditional research methods, it is difficult to determine the distribution state of asphalt mixture aggregates, and it is difficult to obtain relevant information

[0005] Although the above-mentioned research on the distribution state or distribution characteristics of aggregates in asphalt mixtures is described and evaluated through one or more aggregate distribution state parameters, the selection and determination of the aggregate distribution state parameters are not enough in the research. Scientific, not comprehensive enough, not strong representative, biased results, can only partially reflect the actual situation of aggregate distribution

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