Numerical testing method and mechanical property evaluation of large particle size asphalt mixture

Area of Science:

• Civil Engineering
• Materials Science
• Pavement Engineering

Background:

• Large stone asphalt mixture with nominal maximum aggregate size 53 mm (LSAM-50) demonstrates significant technical and economic advantages.
• LSAM-50 is poised to become a key component in constructing long-life asphalt pavements with Chinese characteristics.

Purpose of the Study:

• To thoroughly investigate the mechanical properties and influencing factors of LSAM-50.
• To develop a numerical testing method for assessing LSAM-50 mechanical properties.
• To determine an appropriate specimen size for LSAM-50 performance testing through combined numerical and indoor experiments.

Main Methods:

• Developed a numerical testing methodology for LSAM-50 mechanical properties.
• Utilized a calculation time step of 10⁻³ s/step and specific loading rates (2 mm/min for uniaxial compression, 50 mm/min for splitting).
• Conducted comparative analysis between numerical simulations and indoor tests to validate results and determine optimal specimen size.

Main Results:

• Optimized numerical test parameters for LSAM-50 include a time step of 10⁻³ s/step and loading rates of 2 mm/min (uniaxial compression) and 50 mm/min (splitting).
• The size effect on LSAM-50 testing is eliminated when specimen size reaches 200×160mm, establishing Φ200mm×h160mm as the reasonable specimen size.
• The developed numerical test method shows a low error (less than 10%) when compared to indoor test results.

Conclusions:

• The numerical testing method for LSAM-50 is accurate and reliable, with minimal deviation from empirical data.
• The established reasonable specimen size of Φ200mm×h160mm ensures representative mechanical property assessments for LSAM-50.
• LSAM-50 presents a viable and efficient solution for constructing high-performance, long-lasting asphalt pavements.