Method for determining granularity area of asphalt mixture and for evaluating influence factors

Abstract

The invention relates to a method for determining a granularity area of an asphalt mixture and for evaluating influence factors. The method comprises the following steps: drawing isolines on sections of a rutting test specimen, carrying out a rutting test under conditions of different loads and different times, recording initial breaking positions of the isolines of the sections when the test is finished, collecting the depths of the breaking positions, namely the depths of the granularity areas, averaging the depths of the granularity areas of a plurality of sections to determine the granularity area of the asphalt mixture, and analyzing the influence degrees of different loads and temperatures on the depth of the granularity area of the asphalt mixture by using a grey correlation analysis method, to obtain the correlation degree of the granularity area range with load and temperature, namely obtaining the influence of the load and the temperature on the granularity area of the asphalt mixture. The method provided by the invention has the advantages of being simple and easy in test scheme, high in repeatability, clear and exact in conclusion and helpful to mechanical analysis and calculation of asphalt pavements.

Description

technical field [0001] The invention belongs to the technical field of mechanical response evaluation of asphalt mixture structure, and specifically relates to a method for determining the granularity area of ​​asphalt mixture and determining the influence of temperature and load on the granularity of asphalt mixture based on the contour method and the rutting test. Influencing factor evaluation method. Background technique [0002] Asphalt mixture is a multi-phase mixed material composed of asphalt, aggregates, voids, etc. The loose granular materials are connected into a whole through the bonding ability of asphalt glue, and the mass of aggregates accounts for 10% of the total mass of the mixture. More than 90%, accounting for more than 70% of the volume. Therefore, asphalt mixture is actually a heterogeneous, discontinuous material with prominent granular characteristics. However, the current "Code for Design of Highway Asphalt Pavement" in China stipulates that the mec...

AI Technical Summary

Problems solved by technology

At present, the research on the particle characteristics of asphalt mixture mostly uses image processing and numerical simulation methods, such as the use of digital images, photoelastic mirror technology, X-ray CT, etc. to analyze the aggregate orientation, contact status, segregation, Identify the distribution of asphalt mastic, the distribution of voids, etc., then carry out three-dimensional digital reconstruction of the internal structure of asphalt mixture, and numerically simulate the strength mechanism and macroscopic mechanical behavior of the mixture. These methods and means are very useful for simulating and analyzing the asphalt mixture. Micro-structure and macro-performance is an effective method, but there are obvious shortcomings: (1) The experimental process and data processing are cumbersome and complicated, time-consuming and labor-intensive, and it is difficult to popularize; (2) The current research method focuses on asphalt mixing The physical characteristics of the granularity of the material are ignored, while the mechanical characteristics of the granularity in the stress field and temperature field are ignored.

(3) The evaluation index can not truly reflect the relationship between the granular characteristics of the mixture and its macroscopic mechanical response

Some researchers use the discrete element method to simulate and analyze the mechanical behavior of asphalt mixture, but due to the complex internal structure and environment of the mixture, this method is difficult to accurately simulate and analyze the mechanical behavior of the mixture

Therefore, the current methods are still unable to comprehensively analyze the granular characteristics of the mixture, let alone use its granular characteristics to accurately evaluate and predict the macroscopic mechanical behavior of the mixture. New methods and new ideas are urgently needed to analyze the granular behavior of the mixture. Describe, analyze and evaluate, determine the granular area and continuous area of ​​asphalt mixture in a certain temperature field and stress field, so as to provide more real and reliable information for mixture design, pavement structure design and mechanical analysis

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