An experimental method for measuring the rheological behavior of slurry suspensions

Predictive modeling of natural sediment-laden flows requires rheometric protocols that are both reproducible and time-aware of sediment dynamics. This study establishes a standard measurement protocol for homogeneous sediment slurries using concentric (coaxial) cylinder geometry under laminar, steady-state conditions. Sediment properties – density, mineralogical composition, and grain-size distribution – were used to calculate terminal settling velocities in quiescent media, thereby constraining the maximum allowable test duration; across samples, the resulting maximum settling times were 6–30 min. A Staircase shear-rate function from 10−2 to 102 s−1, interleaved with brief homogenization intervals, was adopted. Logarithmic ramp protocols were discarded because they exclude homogenization and exacerbate time-dependent sedimentation during acquisition. The protocol yielded apparent viscosities from 10−2 to 102 Pa s and shear stresses from 10−1 to 101 Pa, resolving two operational shear-rate zones: 10−1–100 s−1 for yield-stress identification and 100–102 s−1 for constitutive characterization of the flowing regime. The resulting, reproducible workflow enables robust parameterization of slurry rheology and strengthens the basis for hazard-oriented flow models.