This paper presents an experimental study on the dynamic properties of Ottawa Sand treated with Laponite, a synthetic material with a plasticity index larger than 1000%. Resonant column tests show that 1% of Laponite-by dry weight of sand-increases the small strain dynamic properties, the shear modulus (G0 ) and damping (D0), compared to the clean sand. The nanoparticle aggregate induces, with respect to clean sand under same testing conditions, an extension of the linear strain threshold, causing a delay in the excess pore pressure generation, shear modulus degradation, and damping increment as the cyclic shear strain increases. Microscopy imaging of particle-interactions is presented to provide supporting evidence of contact mechanics effects and complement the experimental results. Overall, the results are attributed to the effect of the Laponite at the sand grain-to-grain contact level, inducing a bridge effect in the granular system due to the presence of the nanomaterial.