关键词: 屈服应力;黏度;流变模型;Couette转换

Abstract: The steady state rheological curves of cement paste were determined with control variables of shear rate and rotate speed by means of RHEOLAB QC rotary viscometer, and the effects of testing and rheological methods on the yield stress and viscosity of cement paste were studied through Couette inverse and rheological models.The results show that:results derived from Couette inverse reflect a better effect of testing methods on the measurement, when the gap between van and cup increases, the shear rate derived from rotate speed and particle migration of cement paste increase, and the plastic viscosity increases,while the dynamic yield stress gradually decreases; the friction coefficients of the external cylinder do not change the relative motion between the paste and outer cylinder and have little influence on the dynamic yield stress.Based on the fitting coefficients, Herschel-Bulkley model fits best with the registered data.Based on the standard deviation values,Herschel-Bulkley model has the best stability of dynamic yield stress,and stability of Bingham model is basically the same as modified Bingham model.

Key words: yield stress;viscosity;rheological model;Couette inverse