Bimodular Analysis of Hot-Mix Asphalt

ABSTRACT In this paper, the bimodular (different tensile and compressive moduli) stress distribution in the IDT specimen is determined for different compressive to tensile modulus ratios. The difference between the modulus calculated from the IDT test assuming Hondros' linear elastic stress distribution, and the compressive and tensile moduli is then obtained. The results show that this difference is significantly smaller for the case of the compressive modulus compared to the case of the tensile modulus. Even for a compressive to tensile modulus ratio of 2, the difference from the compressive modulus is small enough (5 to 10%) to be indistinguishable from experimental testing variation. This would explain why IDT experimental results tend to agree with uniaxial compression test results. It however contradicts the assumption that the IDT creep compliance test can approximate the uniaxial tension creep compliance.