Poisson's Ratio of Hot Asphalt Mixtures Determined by Relaxation and Small Amplitude Oscillation Tests

One of the basic material characteristics of solids is Poisson's ratio. Its exact knowledge, including its dependence on time, allows us to model the effect of load, with given boundary conditions, on the behavior of material under consideration. Poisson's ratio, or rather the relationship between the longitudinal and transverse strain, has an important implication in engineering mechanical applications (assessment of pavement structure performance). Currently, Poisson's ratio usually is used as a constant, based on an incorrect assumption that a hot-asphalt mix (HMA) is a linear elastic material. This paper reports Poisson's ratio as a function of time determined from the relaxation and small amplitude oscillation tests on cylindrical specimens. An HMA is considered homogeneous isotropic material, and linear theory of viscoelasticity is applied for the experimental determination of the lateral contraction ratio.