An Analysis of Frost Penetration Depth with Field Temperature Data of Paved Road in Korea

Abstract

The frost penetration depth of paved road in Korea is usually estimated from the freezing index that made temperature data analysis of 30 years and decided the thickness of anti-frost layer. The field monitoring region was divided into three regions by freezing index 550~650°C·day, 450~550°C·day, and 350~450°C·day. Each region has three-section of road pavement such as cutting area, boundary area of cutting and banking, and lower area of banking. The field monitoring system was established both in the section of anti-frost layer and in the section without anti-frost layer. The analysis was conducted for determination of frost penetration depth within the paved road by the field monitoring data. The temperature of subgrade without anti-frost layer shows below zero in centigrade for the region of freezing index 550~650°C·day, up and down around zero degree in subgrade for the region of freezing index 450~550°C·day, and there is no place existed below zero degree in subgrade for the region of freezing index 350~450°C·day. With comparison of field frost penetration depth for the cross-sections of paved road, the cutting area shows the greatest frost penetration depth, and less influence of frost penetration depth for the boundary area of cutting and banking, and the least influenced for the lower area of banking. After all, all the field collected data will be utilized as an important parameters for the design of paved road in Korea. Desing of pavement in seasonal freezing areas should consider the environmental conditions including climate, soil, and moisture content of soil. One of that is caused from effect of these conditions is frost heaving. Jiang and Tayabji(1999) studied on the influence of in-situ moisture content on the seasonal monitoring site. Tomasz(2009), Wu, Zang and Liu(2010) evaluated the factors influenced on the freezing point in the soil water system and long-term thermal effect of the asphalt pavement. The frost penetration depth of paved road in Korea is usually estimated from the freezing index that made temperature data analysis of 30 years period and decided the thickness of anti-frost layer. It may be caused of over-design for pavement design with using the current estimation method of the frost penetration depth. Therefore, this study analyzed the depth of frost penetration for pavement design and the depth of frost penetration of paved road using field monitoring data.