Rheological Characterization of Asphalt Fine Aggregate Matrix Using Dynamic Shear Rheometer

Area of Science:

• Materials Science
• Civil Engineering
• Pavement Engineering

Background:

• The fine aggregate matrix (FAM) is crucial for the field performance of hot asphalt mix (HMA).
• Understanding FAM's material properties is essential for improving HMA durability.
• Previous research has not fully explored the rheological behavior of FAM under various conditions.

Purpose of the Study:

• To investigate the rheological properties of asphalt fine aggregate matrix (FAM).
• To determine the influence of key factors like asphalt content, gradation, and air void content on FAM performance.
• To evaluate the role of fibers in enhancing FAM's resistance to flow.

Main Methods:

• FAM specimens were prepared with consistent filler-bitumen (FB) ratios.
• A non-destructive method was used to fabricate FAM cylinders.
• Rheological responses were analyzed using a dynamic shear rheometer (DSR).

Main Results:

• Rheological performances of FAM are significantly influenced by asphalt content, gradation, air void content, and testing frequency.
• Air void content was identified as the decisive factor for FAM stability.
• Fibers were shown to enhance flow resistance in FAM-F, irrespective of high asphalt content.

Conclusions:

• Air void content is the primary determinant of FAM stability in HMA.
• Fibers contribute to improved flow resistance in asphalt fine aggregate matrix.
• The developed non-destructive fabrication method and testing setup are validated for data reliability.