Experimental Measurement and Modeling of the Complex Poisson’s Ratio of Bituminous Mixtures

A complete characterization of linear viscoelastic properties of bituminous mixtures requires the measurements of the complex Poisson’s ratio. The complex Poisson’s ratio of bituminous mixtures is not easy to obtain because of the high precision required and the limited accuracy of the experimental device. In this paper, three dimensional cyclic tension-compression tests were performed to measure the complex Poisson’s ratio. Two bituminous mixtures were tested: one prepared with classical bitumen and one prepared with polymer-modified-bitumen. In order to measure the complex modulus and the complex Poisson’s ratio, the sinusoidal loadings were applied on the specimens at different temperatures and frequencies. The experimental results show that the complex Poisson’s ratios of bituminous mixtures vary as a function of reduced frequency. The master curve of the complex Poisson’s ratio can be built using the same shift factor for the master curve of the complex modulus. It was verified that the Time-Temperature Superposition Principle and the Partial Time-Temperature Superposition Principle can be applicable for the complex Poisson’s ratio of the classical bituminous mixtures and the polymer-modified-bitumen mixtures, respectively. A linear viscoelastic model with a continuum spectrum called 2S2P1D is used to simulate the 3D linear viscoelastic behavior of tested bituminous mixtures.