Soil viscosity and yield stress measurement using a motorized rheometer

摘要: A motorised soil rheometer was developed at the Department of Agricultural andBioresource Engineering, University of Saskatchewan to determine soil viscosity and yield stress.The device works on the principle of torsional shear applied to a standard vane with controlled strainrate following ASTM standards. Rheological measurements were carried out for a clay loam soil atdifferent soil moisture contents (10, 13, 17 and 20% d.b.) and soil compaction levels (100, 150, 200,300 and 400 kPa) to find their effects on soil viscosity and yield strength. The values of viscosity of aclay loam soil were found to spread in the range of 53x103 to 283x103 Pa.s, while the yield stressvariation had a range of 4 to 28 kPa. Viscosity was highly affected by the compaction levels for themoisture contents tested. Increase in soil compaction was accompanied by a sharp increase in soilviscosity. Yield stress also increased with soil …