Numerical correlation between low temperature SCB fracture and IDT strength of asphalt mixture using FEM analysis

Abstract

Currently, Indirect Tensile (IDT) and Semi Circular Bending (SCB) tests are used for evaluating strength and fracture properties of asphalt mixture at low temperature. While IDT is performed on notchless samples, the SCB peak stress (strength) is obtained on pre-notched specimens which are not representative of initial undamaged pavement conditions. In this paper, the low temperature strength of asphalt mixture is investigated based on IDT and SCB tests, and on 2D finite element simulations. The values of maximum stress at crack tip in SCB simulation are correlated to the experimental IDT strength through non-parametric statistical analysis. The newly proposed relationship can be used to predict the IDT asphalt mixtures strength based SCB fracture tests and, thus, contribute to a better understanding of the low temperature cracking properties in the evolution of asphalt pavements from undamaged to damaged conditions.