A simplified approach in determining the c and φ for asphalt mixtures

Abstract In this study, using the Mohr-Coulomb failure theory, a simplified method was proposed to determine the cohesion (c) and internal friction angle (φ) for asphalt mixtures based on direct tension (DT) strength and indirect tension (IDT) strength or unconfined compressive strength (UCS) and IDT strength. The direct tension (DT) strength, superpave indirect tension (IDT) strength and unconfined compressive strength (UCS) were conducted to verify this method using three asphalt mixtures. It was found that the determination of c and φ values have mean absolute errors of 5.2% and 1.8%, respectively in comparing two methods indicating that the c and φ can be estimated from DT strength and IDT strength or IDT strength and UCS. Further study is recommended to verify using different binder grades and mixture types.