Method for evaluating uniformity of asphalt mixture

Abstract

The invention discloses a method for evaluating the uniformity of an asphalt mixture. The method comprises the following steps: firstly, providing a cylindrical asphalt mixture test piece required by analysis through indoor molding or field sampling; secondly, acquiring a sectional image of the asphalt mixture test piece through an industrial computed tomography (CT) machine or a digital camera, wherein the asphalt mixture test piece is cut through a saw-tooth cutting machine when the digital camera is adopted; thirdly, converting the image into a black-and-white image in a bitmap (BMP) format, and analyzing the black-and-white image to obtain information of each aggregate and each hole in the sectional image of the asphalt mixture test piece, wherein the information comprises perimeter, area, equivalent diameter, coordinates of a long axis and a short axis, position coordinates of a center of mass and the like; and finally, respectively calculating the distribution states of aggregates and holes on the section of the mixture in terms of position distribution, quantity distribution and long axis azimuth distribution of the aggregates and the holes in the mixture so as to evaluate the uniformity of the mixture. On the basis of a digital image technology, the uniformity of the asphalt mixture is directly and quantitatively evaluated. Compared with other methods, the method has the advantage that an evaluation result is more accurate.

Description

technical field [0001] The invention belongs to the field of road engineering, in particular to a method for quantitatively evaluating the uniformity of asphalt mixture. Background technique [0002] The uniformity of asphalt mixture is directly related to the mechanical properties and service life of asphalt pavement. Among the many factors that potentially cause early failure of hot mix asphalt pavement, the most serious is the inhomogeneity of the asphalt mixture. The aggregate gradation and / or bitumen content in the uneven asphalt mixture does not match the requirements in the initial site mix ratio, resulting in large changes in the density and void ratio of the mixture. Studies have shown that: when the asphalt mixture is uneven, the stiffness, tensile strength and fatigue life of the mixture will decrease, and the service life of the pavement will decrease, thereby accelerating the early damage of the pavement. [0003] Asphalt mixture is composed of asphalt, coarse...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the limitations of the existing evaluation methods, the invention provides a method for evaluating the uniformity of asphalt mixture

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