Study on mortar thickness spectrum of asphalt mixture based ontwodimensional image processing method(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2019年01期
- Page:
- 9-16
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Study on mortar thickness spectrum of asphalt mixture based ontwodimensional image processing method
- Author(s):
- NI Fujian; YAO Linyi; JIANG Jiwang
- School of Transportation, Southeast University, Nanjing 210096, Jiangsu, China
- Keywords:
- road engineering; mortar thickness spectrum; digital image processing; asphalt mixture; microstructure
- PACS:
- -
- DOI:
- -
- Abstract:
- In order to study the constitution law of mortar thickness of asphalt mixture, a method of calculating mortar thickness of asphalt mixture based on the principle of the shortest contact distance was put forward, considering the weakest direction of contact between aggregates. High precision twodimensional scanner was used to obtain the twodimensional slice images of asphalt mixture. Asphalt mortar was defined as a composition of asphalt and fine aggregates less than or equal to 1.18 mm. MATLAB image processing method was used to analyze the spatial structure of mixture mortar. Several indexes including average mortar thickness, the mode and concentration ratio of mortar thickness spectrum were proposed and statistically analyzed. The influences of different compaction times, asphalt type, the maximum nominal particle size and gradation type on the mortar thickness of asphalt mixture were researched for six different types of mixtures. The results show that the proposed calculation method of mortar thickness is suitable for the analysis of constitution law of asphalt mixture mortar thickness. Mortar thickness spectrum can be fitted well by lognormal distribution model. With the increase of compaction times, there are minimum values in average mortar thickness and the mode of mortar thickness spectrum, while mortar concentration has a peak value which indicates that overpressure will destroy the stability of mortar, and it is important to choose a reasonable compaction times, the maximum nominal particle size of smaller aggregates, suspended dense structure and modified asphalt mixture tend to be lower. Meanwhile, they would concentrate on smaller mortar thickness with higher concentration ratio, the maximum nominal particle and gradation type had the most significant influences, and asphalt type has a significant influence on the concentration ratio of mortar thickness spectrum. The impact of compaction times is not significant but still shows some obvious rules. 4 tabs, 4 figs, 26 refs.
Last Update: 2019-01-28