Antierosion Rheological Characteristics of Gaomiaozi Bentonite Suspension

Abstract:

The rheological characteristics of Gaomiaozi(GMZ) bentonite suspension with different watersolid ratio, salt type and concentration were investigated by using Brookfield DVIII rheological device, and the yield stresses of bentonite suspensions were obtained from rheological curves, then the yielding initial water velocity was calculated with a consideration of the Stoke law. The results showed that the rheological curves of bentonite suspension moved lower with the increase of watersolid ratio. For the bentonite suspension with a watersolid ratio below 5.0, the suspension presented a characteristic of pseudoplastic fluid when shearing rate was slow, while the rheological curve slope tended to be constant when shearing rate exceeded a certain value. For the bentonite suspension with a watersolid ratio above 5.0, the suspension gradually presented a characteristic of newtonian fluid with the increase of watersolid ratio; when the concentration of NaCl solution increased, the yielding stress of bentonite suspension firstly decreased and then increased, while the yielding stress would be reduced all through the test with the increase of CaCl2 solution’s concentration; the yielding initial water velocity of bentonite suspension was between 10-4~10-2 m?s-1 under the condition in this study.

Key words:bentonite; erosion; rheological characteristic; yield stress