| |
| This paper aims to find a fast testing method for the asphalt mixture by using the digital image processing method. For the composition of the asphalt mixture contains the asphalt content and the mineral aggregate gradation, the color comparing method is provided to test the asphalt content and the particle analysis method is provided to analyse the mineral aggregate gradation. The normalized histogram of the asphalt mortar part in the asphalt mixture image is compared with that of the asphalt mortar image with known filler bitumen ratio in the colour comparing method to decide the filler bitumen ratio of the asphalt mixture tested. During the mineral aggregate gradation test by using the image processing, the stand image with known gradation is analysed and the average passing rate of each sieve is calculated by using the particle analysis parameters. Then, the correction parameter of each sieve is obtained. In the following test of core sample drilled form the asphalt pavement constructed with the same batch asphalt mixture, the same methods are used consequently to obtain the passing rate of each sieve. The passing rate obtained by the image processing and the correction parameter of each sieve are combined correspondingly to get the final passing rate. The analysis of the asphalt content result show that the asphalt content can be decided accurately if the asphalt mortar image database is rich enough. And the passing rate error of each sieve obtained by using the image processing method is smaller the 2%, which is acceptable. The image-based test of the asphalt mixture composition is worthy practicing in the pavement engineering.
|
|
| Keywords:image processing, gradation, normalized histogram, asphalt mixture composition, particle analysis |
|
