Frost monitoring of the Finnish road network

At present, maintenance of road networks is one of the main functions of the Nordic road administrations and also the budget area where the largest expenditures exist. Managing and predicting maintenance needs makes it possible to focus the scarce resources available to where they are most needed. The better and more accurately we can assess road deterioration, the easier it becomes to plan long-term and cost-effective maintenance processes. The risks posed by e.g. climate change require more comprehensive tools with interactive data managing than what is currently available. In the spring, the road structures are most vulnerable when the frost thaws and the water remaining in the structures begins to dissolve. Unabsorbed water decreases road load capacity. Frost data monitoring is important information for predicting the behavior of the road network. It is important to know when the melted water has evaporated and drained off to be sure that it is safe for heavy vehicles to use the road again. The data also helps to work systematically. For example, it can be used to plan schedules for routing fitness measurements and paving and road repairs. The data is also helpful in frost damage surveys. This paper examines the frost penetration based on real-time in-situ monitoring. The study includes the construction of the in-situ monitoring network and calculational analysis of the frost penetration and thaw. The research presents results for frost penetration cycles in different parts of Finland and also presents the change of the cyclic patterns.