Temperature in pavement and subgrade and its effect on moisture

This paper gives the results of experimental research of temperature variation and its effect on distribution of moisture in pavement and subgrade of a highway located in the eastern region of Kazakhstan. The sensors consisting of two elements have been used to measure temperature and moisture. The first of them is designed for measurement of temperature and based on the effect of thermal resistance, and the second one based on diamagnetic penetration allows measuring of moisture. Peculiarities of temperature variation in time in pavement layers and points of subgrade, temperature distribution in the depth at different time moments have been described. Important characteristics have been determined – duration of a frozen condition and freezing, average rates of freezing and defreezing in points of pavement and subgrade located in various depths. Quantity of unfrozen water in subgrade soil depends on negative temperature and initial moisture and it is satisfactorily approximated by semi-logarithmic function. Keywords: Pavement, Subgrade, Sensors, Temperature, Moisture, Unfrozen water