Time- and temperature-dependent rheological properties of cemented paste backfill that contains superplasticizer

The use of suitable superplasticizers in the production of cemented paste backfill (CPB), a mix of water, binder and tailings particles, is becoming prevalent due to their ability to improve flowability without undermining other important engineering properties. Their performance under different ambient temperatures found in various regions is not well understood. No research has been conducted to understand the effects of temperature on the rheological properties of CPB with superplasticizers. Therefore, the aim of this study is to investigate the effects of a superplasticizer on the rheological properties, specifically yield stress and viscosity, of CPB prepared and cured under different temperatures. CPB mixes containing 0%, 0.05%, 0.125%, and 0.25% Master Glenium superplasticizer were prepared, and cured for 4 h at three different temperatures of 2 degrees C, 20 degrees C and, 35 degrees C. Yield stress and viscosity were determined at different time intervals over the period. Additional tests, such as pH, thermal analysis and zeta potential analysis were also conducted. It was found that an increase in the ambient temperature leads to higher yield stress and viscosity of CPB treated with superplasticizer. However, less amount of superplasticizer is required to maintain a sufficiently fluid CPB within few hours of production. Additionally, the results from the study showed that different dosages of the superplasticizer are required for different tailings types to achieve the same level of flowability. The findings of this study will be beneficial in the design and production of CPB material. (C) 2019 Elsevier B.V. All rights reserved.