Ake Hermansson[6], Robert Charlier, Frederic Collin, SigurSur Erlingsson, Lyesse Laloui and Mate Srsen
Abstract Temperature highly affects pavement performance. High and low temperatures not only affects the viscosity of asphalt concrete but also has an impact on the moisture flow within pavements. At temperatures below 0°C the freezing of pavements dramatically changes the permeability and frost action might occur forcing water to flow upwards to the freezing front resulting in frost heave and other pavement distress.
Keywords Heat transfer ■ conduction ■ temperature ■ frost
The thermal state may have a major influence on the moisture condition of a pavement or foundation. Thermal gradients due to temperature changes on the surface will induce not only heat flow in the pavement but also moisture flow.
Freezing and thawing are definitely the most important aspects linking temperature to water flow. Furthermore, a freezing temperature significantly reduces the permeability of soils but also increases the moisture flow caused by hydraulic gradients due to ice lens formation in the frozen soil.
Moreover, the water viscosity depends on the temperature; at higher temperature, some water will flow in the vapour phase, and this depends on the temperature gradient. Heat flow and moisture flow are, therefore, linked processes with complex interaction between them. This chapter will describe the basis of heat transfer laws and models.
