Analysis of temperature stress and critical heating temperature for hydronic airport pavement

The hydronic heated pavement system has been widely used for snow and ice removal in airports and other transportation infrastructure facilities because of its good snow melting efficiency and environment friendliness. However, the study of the temperature stress distribution in hydronic pavement and the corresponding critical operation method shows many insufficiencies, which allows security problems during system operation. This paper investigated the temperature stress of the hydronic pavement near the pipes with a 3D finite element model. This model was validated by the measured temperature stress in a full-scale hydronic snow melting experiment system. The locations of the maximum compressive and the time-varying tensile stress in the hydronic pavement were reported. The maximum temperature stresses of the hydronic pavement with various design and operation parameters were compared, and the sensitive parameters were proposed. In particular, the critical fluid temperature with various design and weather parameters was presented by comparing the maximum temperature stress in the pavement with the failure strength of concrete material. The findings show the maximum compressive stress appears near the hydronic pipe, and the maximum tensile stress appears at the midpoint between two adjacent pipes after heating for 2 h. Maximum tensile stress increases with pipe embedded depth, pipe diameter, fluid temperature, and pavement capacity, but decreases with air temperature and pipe spacing. To ensure the safety of hydronic pavement, the critical fluid temperature under different conditions is controlled within the range from 38 °C to 77 °C.