P10

MEASUREMENT OF RHEOLOGY OF SOIL SLURRIES WITH A HELICAL RIBBON IMPELLER

The goal of this research is to establish rheological characteristics of different soil slurries and to develop correlations of rheological parameters with the nature and concentration of soil in the slurry. The rheological characteristics of soil slurries are determined by measuring power required to agitate the helical ribbon (HR) impeller at different speeds of agitation after calibrating the impeller.

Aqueous solutions containing different concentrations of xanthan gum are being used to calibrate the relative viscometer and to establish the effective shear rate agitation rate relationships. Results dealing with validity of the Metzner-Otto relationship for the impeller system will be presented. These will be utilized to calculate the shear stress - shear rate relationships for different soil slurries. The concentrations to be investigated are 10, 20, and 30% (w/v) aqueous slurries of three different types of soils. The experimental results will be presented and discussed.

Key words: rheology, soil slurry, helical ribbon impeller, power number, reynolds number