Development of a Geothermal Snow Melting System for Highway Overlays and Its Performance Validations

Abstract

Abstract Geothermal energy has been applied to a snow melting system for highway overlays. This paper described practical steps for the design, construction, and validation of the system. These steps were carried out both in a laboratory and in the field. In the laboratory, a series of heat conductivity tests were carried out to understand the heat transfer characteristics in a pavement layer and to determine an optimum pipe pitch at 50 mm depth. Steel fiber reinforced concrete (SFRC) was proposed as the pavement material to make the system durable in overlays subjected to heavy traffic, and its resistance to construction cracks was tested in the field. In 2009, the first trial version of the geothermal snow melting system was built into a 50 mm thick SFRC overlay. Since then, its snow melting performance has been monitored and evaluated under different snowfall accumulations and intensities. Given the design variables, it took about 30 to 60 minutes to remove snow and ice even under heavy snowfalls. Finally, the construction and operation costs of the developed system were calculated and compared with those of other snow melting methods. It is expected that the developed system will be installed on tunnel entrances and bridge decks on highways once its durability is verified under heavy axle loads.