Asphalt mixture three-dimensional void connectivity characterization and evaluation method

Abstract

The invention discloses an asphalt mixture three-dimensional void connectivity characterization and evaluation method. The method comprises the following steps: preparing an asphalt mixture rut plate test piece, cutting a drill core, and carrying out CT (Computed Tomography) on a core sample; carrying out superposition reconstruction and morphological processing on a projection image obtained by scanning, and carrying out threshold segmentation to identify voids of the core sample, asphalt mortar and aggregate; calculating the void ratio of the reconstruction model, comparing the void ratio with the real void ratio of the sample, and extracting a void ball-stick system of the sample by using a maximum sphere algorithm to carry out visual representation on the three-dimensional distribution of voids; calculating the coordination number of the void ball-stick model and the equivalent length of a throat formed by void communication so as to evaluate the void communication degree; and performing CT scanning on the core sample subjected to wheel rolling again, and reflecting the stability of the void structure of the mixture by virtue of a communication parameter change rate before and after scanning. The method provides a novel way for representing the void connectivity of the mixture on a three-dimensional scale level, and is beneficial to comprehensively understanding the spatial distribution characteristics of the voids of the asphalt mixture.

Description

technical field [0001] The invention relates to a characterization and evaluation method for three-dimensional void connectivity of asphalt mixture, and relates to the technical field of road engineering. Background technique [0002] As a multiphase heterogeneous material, asphalt mixture consists of asphalt, aggregates and interstitial spaces dispersed between two phases. During the service of asphalt pavement, due to the unavoidable erosion of rainwater, water can easily penetrate into the internal voids of asphalt mixture, thereby destroying the bond between asphalt and aggregate, causing asphalt to fall off from the surface of aggregate, resulting in loosening and peeling. and other diseases. Since the void is the main channel for water seepage, its connectivity is an important factor affecting the stability of the asphalt mixture skeleton and the performance of water damage resistance. In the past, the analysis of the connectivity of asphalt mixture voids could only ...

AI Technical Summary

Problems solved by technology

Although CT scanning has been gradually used in the visualization and characterization of mixture voids recently, most of the research on mixture voids is still limited to the simple linear superposition of sliced ​​images of asphalt mixtures, without considering the void structure in the vertical direction. Randomness and variability in the vertical direction

In addition, the research focuses on the regular description of the distribution characteristics of voids, while ignoring the influence of connectivity on the water damage resistance of asphalt mixtures

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