Determining the bulk viscosity in clay–sand mixtures: A combined investigation with slump tests and lattice Boltzmann simulations

Viscosity measurements for clay slurry and sand mixtures can be challenging for standard rheometers because of the sand particles. To solve this, we suggest combining slump test experiments with numerical simulations. Slump tests are performed on clay–sand mixtures, with the sand's volume fraction varying between 0≤ϕ≤0.32. The run-out distance of the slump is tracked over time using a high-speed camera. By comparing the results of lattice Boltzmann simulations with the experimental data, we can accurately estimate the mixture's overall viscosity. Our findings reveal that fluid consistency increases significantly with ϕ, consistent with predictions made by the Maron–Pierce formula.