Dynamic behavior of sand-bitumen mixtures using large-size dynamic hollow cylinder tests

Dynamic behavior of sand-bitumen mixtures was investigated using a series of dynamic hollow cylinder tests. The effects of different parameters including bitumen content, loading frequency and bitumen viscosity on shear modulus and damping ratio of the mixtures were evaluated in detail. The results showed the added bitumen increased shear modulus of the mixture up to about 20% for bitumen content of 3.5% in the range of shear strains between 0.01% and 0.1%. Such an increase was negligible at shear strains beyond 0.3%. Moreover, the added bitumen boosted damping ratio of the mixtures up to about 10% for bitumen content of 3.5% at shear strains beyond 0.3% while this increase was only about 5% at shear strains less than about 0.1%. Damping ratio and shear modulus of the mixtures changed with the frequency of applied loading mainly due to the viscous behavior of the bitumen. It was also found that using more viscous bitumen augmented damping ratio and shear modulus of the mixtures.