Investigation on Inherent Anisotropy of Asphalt Concrete Due to Internal Aggregate Particles

Asphalt concrete (AC) exhibits significant inherent anisotropic behavior due to the preferential orientation of internal aggregates. In previous work, the inherent anisotropy of compacted AC sample was quantified by using the inclination angles of internal aggregate particles. However, limited attention has been devoted to study how to predict the inherent anisotropy degree of AC through the aggregate geometric parameter before AC specimen compaction. Moreover, the relationships between the inherent anisotropy of AC and geometric parameters of aggregate particles have not been established. In this paper, four types of AC specimens were prepared using the Marshall compaction and wheel rolling method. The modified vector magnitude developed in previous work was validated in this paper and used to quantify the inherent anisotropy of the four types of AC. The cross sections of each specimen were scanned to measure the inclination angle, surface area, and aspect ratio of the aggregates, which were then employed to calculate the modified vector magnitude. The geometric parameters of aggregate particles (>2.36 mm) in each AC specimen was measured using digital image processing before specimen compaction. The relationships between the geometric parameters of different-sized aggregate particles and the modified vector magnitude of compacted AC specimen were developed for each type of AC. Results show that the modified vector magnitude is capable of quantifying the inherent anisotropy of AC. The contribution to the inherent anisotropy of each size aggregate is quite different. Aggregates with the size of 9.5~13.2 mm make the greatest contribution to the inherent anisotropy of AC with the nominal maximum particle size (NMPS) of 13.2 mm.

Language

  • English

Media Info

  • Media Type: Web
  • Features: References;
  • Pagination: pp 39-48
  • Monograph Title: Transportation Research Congress 2016: Innovations in Transportation Research Infrastructure

Subject/Index Terms

Filing Info

  • Accession Number: 01872056
  • Record Type: Publication
  • ISBN: 9780784481240
  • Files: TRIS, ASCE
  • Created Date: Jan 30 2023 10:27AM