Drainage asphalt mixture gradation design method based on virtual test

Abstract

The invention discloses a drainage asphalt mixture gradation design method based on a virtual test. According to the method, three groups of coarse aggregates are trial-matched according to aggregateraw materials to form different PAC gradations; a coarse aggregate mixture discrete element model with the particle size being 2.36 mm or above is generated according to trial grading; carrying out avirtual uniaxial penetration test, and obtaining a critical load and pressure head displacement according to the uniaxial penetration deformation stress diagram; extracting coordination numbers, contact proportions, force chain distribution and displacement conditions of aggregate particles of each grade at critical load points, and visualizing a skeleton structure; and comprehensively comparing various skeleton mesoscopic indexes of the three groups of grading schemes, and selecting one group with the optimal overall mechanical properties as a coarse aggregate part for designing grading. According to the method, the state of the skeleton structure under different gradations can be visually observed, and the problems of skeleton structure loss, low bearing capacity and the like caused by only paying attention to the void ratio and neglecting optimization of coarse aggregate composition in a current method are solved.

Description

technical field [0001] The invention relates to an asphalt mixture design method, in particular to a drainage asphalt mixture gradation design method based on a virtual test. Background technique [0002] The gradation skeleton structure of drainage asphalt mixture is an important guarantee for its bearing capacity. Generally, macroscopic parameters such as coarse aggregate void ratio VCA are used to judge whether the skeleton is formed, but conventional laboratory tests cannot observe the skeleton formation inside the mixture; at the same time At present, the focus of the gradation design of drainage asphalt mixture is to achieve the design target void ratio. However, even under the same void ratio, the skeleton structure of the mixture may be quite different, and there is room for optimization of the coarse aggregate composition. With the development of computer simulation technology, discrete element software has a great application space in the simulation of conventional...

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Problems solved by technology

[0002] The gradation skeleton structure of drainage asphalt mixture is an important guarantee for its bearing capacity. Generally, macroscopic parameters such as coarse aggregate void ratio VCA are used to judge whether the skeleton is formed, but conventional laboratory tests cannot observe the skeleton formation inside the mixture; at the same time At present, the focus of the gradation design of drainage asphalt mixture is to achieve the design target porosity. However, even under the same porosity, the skeleton structure of the mixture may be quite different, and there is room for optimization of the coarse aggregate composition.

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