Sammendrag
Frost action mainly develops in the frost-susceptible subgrade soils, leading to ice lens formation, surface heave, and eventually, to pavement deterioration (Konrad & Lemieux, 2005). Frost action in the base and subbase granular layers is often ignored, because these materials are usually not considered to be frost susceptible. This may not necessarily be the case. The presence of fines in these layers can modify their frost susceptibility and cause severe degradations. This paper presents the results of an experimental study of the frost heave test in closed drainage system and estimation of thermal conductivity and frost penetration depth for crushed rock material used in road construction. The influence of fines on the frost susceptibility of crushed aggregates was established by laboratory frost heave test. A total 10 samples with fine content of 5%, 10% and 15% were investigated. At the same time some estimation of thermal conductivity and frost penetration depth for all tested samples were made. It was established that even for a closed system, without access of water, frost heave can occur just from redistributing water if fines content exceeding 10% and water content is around 7% or higher. It is also shown that predicted thermal conductivity values, obtained for dry crushed rock, can increase with 75% by increasing the dry density 15%. Finally, rough estimations of the frost penetration depth for crushed rock material were introduced showing depth variation for different water content.
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