Comparison of Semi-Circular Bending and Indirect Tensile Strength Tests for HMA Mixtures

This paper presents the comparison between the results of the Semi-Circular Bending (SCB) test and that of the Indirect Tensile (IDT) test in characterizing the tensile strength of hot-mix asphalt (HMA) mixtures. Analytical and numerical simulations were employed to interpret the experimental results. IDT test, a standard test method of AASHTO and ASTM, is adopted by most state highway agencies. Despite its broad usage and many advantages, the permanent deformation under the loading strips is undesirable and in some cases unbearable for the evaluation of the cracking potential of asphalt mixes. SCB test could significantly reduce the loading strip-induced permanent deformation and thus is more suitable IDT for evaluating tensile properties of HMA mixtures. The results from this study indicated that SCB and IDT test were fully comparable and convertible.