Experimental and numerical analysis of the critical heating strategy for hydronic heated snow melting airfield runway

Hydronic heated technology is an efficient and controllable method for airfield-runway snow removal. The heating strategy plays an important role in the application process. Nowadays, the users only consider the snow melting performance of pavement to determine the heating strategy, however the thermal stress of pavement is another considerable but missing aspect for the design of hydronic heated snow melting pavement. This paper investigated the thermal strain distribution of hydronic pavement through the digital-image-correlation and fiber Bragg grating strain sensors in a full-scale field experimental system. Thereafter, the thermal stress field of hydronic heated pavement was analyzed by a two-dimensional numerical model which contains the pavement temperature, thermal strain, and thermal stress distribution. Model validation results indicated that pavement temperature and thermal strain distribution between the experiment and the model were in good agreement. Numerical results showed that the remarkable compressive stress was observed near the hydronic pipe, and the maximum tensile stress appeared in the midpoint between two pipes at the depth of the pipes. The maximum thermal stress of pavement increased with fluid temperature but decreased with air temperature. The comparison results between the maximum thermal stress and mechanical strength of pavement show that the critical heating temperature increased with air temperature. The critical fluid temperature °C = 73 °C + 1.17 × ambient air temperature °C. The obtained results could ensure the security of hydronic heated snow-melting airfield-runway.