Freeze–thaw and consolidation tests on Suncor mature fine tailings (MFT)

This paper presents the findings of a laboratory investigation of the effects of freeze–thaw, and sulfuric acid and quicklime amendment on Suncor mature fine tailings (MFT) post-thaw geotechnical behaviour and soil micro and macro-fabric. This paper gives the results of a consolidation test program on Suncor MFT using a large strain consolidation apparatus along with constant head flow tests to evaluate the void ratio versus effective stress and void ratio versus hydraulic conductivity data for three types of MFT specimens. The large scale and small scale fabric (macro-fabric and micro-fabric) of these specimens were also examined. The results indicated that freeze–thaw can effectively reduce the initial void ratio and the compressibility of untreated and amended MFT. Freeze–thaw can also significantly increase the hydraulic conductivity of MFT, which in combination with reduced compressibility enhances the MFT consolidation. These results were supported by changes observed in the macro and micro-fabric of the tested MFT specimens.