Effects of temperatures and pH values on rheological properties of cemented paste backfill

In this study, different influence mechanisms associated with temperatures and pH values were investigated through cemented paste backfill (CPB) systems. CPB samples were prepared with temperatures ranging from 10 to 50 degrees C in 10 degrees C increments and pH values of 3, 7, and 13. Then, the CPB mixture were subjected to rheological tests, thermogravimetric analysis (TG), derivative thermogravimetry analysis (DTG), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Results demonstrated that the temperatures had significant effects on the rheological properties of CPB, whereas the effects of pH values were relatively unapparent. Higher temperatures (over 20 degrees C) were prone to bring higher shear stress, yield stress, and apparent viscosity with the same pH value condition. However, an overly high temperature (50 degrees C) cannot raise the apparent viscosity. Non-neutral conditions, for pH values of 3 and 13, could strengthen the shear stress and apparent viscosity at the same temperature. Two different yield stress curves could be discovered by uprising pH values, which also led to apparent viscosity of two various curves under the same temperatures (under 50 degrees C). Microscopically, rheological properties of CPB were affected by temperatures and pH values which enhanced or reduced the cement hydration procedures, rates, products and space structures.

Automated summary

This study investigated the influence mechanisms associated with temperatures and pH values on cemented paste backfill (CPB) systems. The results showed that temperatures had significant effects on the rheological properties of CPB, while the effects of pH values were relatively unapparent. Higher temperatures and non-neutral pH conditions were found to increase shear stress and apparent viscosity in the CPB samples.