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PRELIMINARY STUDY OF THE INFLUENCE OF TEMPERATURE AND SALINITY ON THE THERMAL PROPERTIES OF HARDENING CEMENTED PASTE BACKFILL

Session: Mining Geotechnique II / Géotechnique minière II

Fabrice BEYA KAZAMBUA, UQAT (Canada)
Mamert Mbonimpa, UQAT (Canada)
Tikou Belem, UQAT (Canada)
Mostafa Benzaazoua, UQAT (Canada)
Kayumba Kalonji, UQAT (Canada)
Serge Ouellet, Agnico Eagles Mines Limited (Canada)

Thermal curing conditions of cemented paste backfill (CPB) in mine stopes with frozen walls in the permafrost can be assessed using numerical modeling. For this purpose, thermal conductivity and capacity functions of CPB with respect to curing time and temperature are required. In permafrost regions, CBP mixing water is expected to contain brine. The goal of this study was to investigate the influence of temperature and salinity on CPB’s thermal properties. KD2 Pro apparatus was used to determine these properties for different CPB mixtures prepared at a solid mass concentration of 76.3%, with 0% (control) and 5% contents of type HE Portland cement. Mixing water with salt concentrations from 0 to 1% was also studied. Changes in thermal properties of CBP were measured at temperatures of -8°C, 2°C and 22°C. Results indicated that binder content (0, 3, and 5%), salt concentration in the mixing water (0 – 1%) and positive temperatures (2 and 22°C) have a negligible influence on thermal properties with curing time (0 - 28 d). However, freezing conditions (-8°C) has significant effect on these thermal properties.