Authors: Wu, AX; Cheng, H; Yang, Y


Cite As:
Wu, AX, Cheng, H & Yang, Y 2017, 'Thixotropic behavior of paste', in A Wu & R Jewell (eds), Proceedings of the 20th International Seminar on Paste and Thickened Tailings, University of Science and Technology Beijing, Beijing, pp. 66-73.

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Abstract:
Structure fluid can be broken under shear and rebuilt at the static state because of its thixotropy. The thixotropic behavior of paste slurry in transportation causes a continuous decrease of yield stress and plastic viscosity with time. There is no generally accepted method to measure the thixotropy of paste materials. In this paper, the curve of rheological properties was divided into three parts based on the rheological behavior, and a number of problems were identified using the thixotropy loops measurement to characterize the thixotropy of cement paste. Stress relaxation was considered and the variation of shear stress with time under a constant shear rate was also measured, establishing a yield stress prediction model and plastic viscosity prediction model after considering aspects of paste materials. The total thixotropic time was found to have no relevance to shear rate. Due to paste thixotropy, shear flow area increased and plunger flow area decreased over time and eventually stablized. According to the difficulty level, a standard which divides transportation into different stages was first proposed.

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