沥青混合料自愈合性能与砂浆厚度分布特征关系

Translated title of the contribution: Relationship Between Thickness Distribution Characteristics of Asphalt Mortar and Self-healing Behavior of Asphalt Mixture

Ji Wang Jiang, Zhen Leng, Ze Jiao Dong, Fu Jian Ni

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

The microstructure of the asphalt mortar considerably affects the macroscopic self-healing behavior of the asphalt mixture; however, there are insufficient indexes that explain this relationship. Therefore, an image analysis method was proposed in this study to characterize the microstructure of the asphalt mortar, and the effect of the complex mortar thickness distribution on the self-healing properties of the asphalt mixture was investigated. First, the calculation method for the mortar thickness was optimized, and new morphological indexes were proposed to quantify the distribution of asphalt mortar, namely, average mortar thickness (Tm) and standard deviation of the mortar thickness distribution (SDt). Then, two-dimensional images of six selected asphalt mixtures with different gradations and nominal maximum aggregate sizes (NMAS) were obtained and analyzed to verify the effectiveness of the proposed image analysis method. Finally, the self-healing index (H) of the asphalt mixture was determined by using semi-circular bending (SCB) fatigue tests with and without rest time. The relationship of H with the proposed microscopic indexes was investigated. Both the gradation type and NMAS were found to affect the mortar thickness distribution. The poor correlation between the macroscopic volumetric indexes: voids in the mineral aggregate (VMA) and voids filled with asphalt (VFA), and the microscopic indexes of asphalt mortar verifies the limitation of the volumetric properties for characterizing the microstructure of asphalt mortar in mixtures. Both the average thickness and distribution uniformity of the asphalt mortar affected the healing index. The comprehensive index, Tm/SDt, was strongly correlated with the healing index, indicating that it can be used as an effective index to evaluate and predict the self-healing efficiency of asphalt mixtures.

Translated title of the contributionRelationship Between Thickness Distribution Characteristics of Asphalt Mortar and Self-healing Behavior of Asphalt Mixture
Original languageChinese (Simplified)
Pages (from-to)192-200
Number of pages9
JournalZhongguo Gonglu Xuebao/China Journal of Highway and Transport
Volume33
Issue number10
DOIs
Publication statusPublished - Oct 2020

Keywords

  • Asphalt mortar thickness
  • Digital image processing
  • Meso-structure of asphalt mixtures
  • Road engineering
  • Self-healing

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Transportation
  • Mechanical Engineering

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