Journal of Cold Regions Engineering

This paper presents a framework for combining the chemistry and mineralogy of oil sands mature fine tailings (MFT) along with geotechnical knowledge of freeze-thaw processes, large strain consolidation and MFT behavior to develop a conceptual model incorporating the physicochemical processes associated with freeze-thaw dewatering. A conceptual model of freeze-thaw dewatering of oil sands MFT is proposed, which accounts for the release of water, change in mechanical and hydraulic properties, and alteration of the micro and macrofabric of MFT under one-dimensional conditions. Various solutions to the Neumann thermal model were examined to assess their ability to predict the rate of freezing and thawing of MFT. Models for predicting thaw and postthaw settlement were discussed as they pertain to freeze-thaw dewatering of MFT.

In cold regions, snow and ice cause serious safety problems to the transportation system. South central Alaska, particularly Anchorage, is susceptible to a number of icing events resulting from frequent freeze/thaw cycles in the winter season. Traditionally, deicing has been accomplished by mechanical, chemical, and thermal methods. However, these methods cause problems such as damage to pavement, pollution in the environment, corrosion to vehicles and reinforcing steel in concrete, or being too expensive. A new type of roadway deicing system on the basis of commercially available carbon fiber tape is proposed. This paper presents the design of a deicing heating panel, the layout and construction of the test sidewalk, experimental results and analyses, and cost comparison with other deicing systems. Experimental results including system performance, deicing time, energy consumption, deicing cost, and temperature variation with time and location are presented. The sensitivity of the deicing cost to ambient air temperature, wind chill, and snow density is also analyzed. Finally, this system is compared with other deicing systems in annual operating cost, unit cost, power density, and installation cost. The cost comparison shows that the present deicing system demonstrates higher energy efficiency and lower installation cost among the systems compared and has great potential for applications in cold regions.