Dynamic behaviour of granular soil materials mixed with granulated rubber: influence of rubber content and mean grain size ratio on shear modulus and damping ratio for a wide strain range

Abstract

The escalating disposal of end-life tires has led to an urgent need for efficient reuse. The positive environmental impact of the application of this material in large-scale civil engineer construction, such as soil-retaining structures, or as seismic isolation technique, stems not only from the reuse of the tires, but also from the effect this material inherits to the response of these structures. The soil material properties in the form of shear modulus and damping degradation curves, G–γ–D, are key parameters in the numerical analysis of site-specific seismic response and seismic design of structures. To this end, the effect of the dynamic shear strain, γ, on the shear modulus, G, and damping ratio, D, of granular soils mixed with granulated rubber is studied. An experimental approach is presented, employing resonant column and cyclic triaxial tests to obtain an insight on the response of these mixtures in a wide band of dynamic strain. A range of rubber content in the mixture up to 60% per weight is tested, and the influence of the mean grain size ratio of the mixed materials is investigated.