Effect of Stress Singularity on the Scaling Law of Asphalt Mixture Strength at Low Temperature

Abstract

Asphalt mixtures behave in a quasibrittle manner at low temperatures and, consequently, its nominal strength strongly depends on the structure size. Most of the research performed in the past has addressed this phenomenon either on notched or unnotched specimens; however, the evolution of the pavement conditions can lead to the formation of weaker stress singularities than the conventional −1/2 crack-tip singularity. In this paper an experimental study is performed to evaluate the effect of different stress singularities of notchless, V-notch and straight-notch beams of asphalt mixture on the strength size effect. The analysis is based on a generalized weakest link model that combines the energetic scaling of fracture with the strength statistics. The model captures the transition from the statistical to the energetic scaling as the magnitude of the stress singularity increases.