Experimental on thermal performance of bridge deck with hydronic heating system

Abstract

Hydronic heating systems with geothermal heat exchangers are one of the innovative methods for bridge deck deicing in winter, which avoids infrastructure corrosion and environmental pollution caused by chemical methods. This paper focused on field tests of the thermal performance of a bridge deck with a hydronic heating system under heating conditions. The inlet fluid temperatures were kept constant to study the transient heat flux through outlet fluid temperatures under different ambient temperature conditions. Three different inlet fluid temperatures of 30.5 °C, 35.5 °C, and 41.0 °C were considered in the field test. The objective of this paper is to study the influences of the air temperature, slab temperature, and inlet fluid temperature on the heat exchange flux and the thermally induced stresses due to heating. The results indicate that the inlet fluid temperature should be controlled above 2.3 times the absolute value of the air temperature to keep the slab surface temperature above 0 °C when the air temperature is below 0 °C. The thermally induced stresses caused by operating the system are smaller than 5% of the strength of the concrete, which are negligible.