Stainless Steel Wires-Modified Asphalt Concrete for Self-Heating and Self-Deicing

Stainless steel wires (SSWs)-modified asphalt concrete with stable long-term properties and high electrical conductivity as well as without puncturing vehicle tires is expected to become a promising multifunctional pavement material especially for solving road icing problems in cold climates. Hence, the electrical/thermal, self-heating, and self-deicing properties of SSWs-modified asphalt concrete were investigated in this study. Meanwhile, the measures for increasing the electro-thermal conversion efficiency of composites were explored. 0.75 vol% SSWs reduced the resistivity of asphalt concrete by at least eight orders of magnitude and increased the thermal conductivity by 30.38%. Preapplying a 60 V voltage instantaneously before applying voltage to utilize the breakdown effect on interface capacitors between SSWs, and employing the three-piece electrode arrangement for improving the overlapping probability of SSWs, significantly enhanced the self-heating power, peak/average temperature increase, and self-heating rate of SSWs-modified asphalt concrete by at least three times. The temperature on the top surface of SSWs-modified asphalt concrete slab (with size of 30 cmx30 cmx5 cm) under 60 V voltage increased by 24.1 degrees C with a power density of 827.37 W/m2 for 90 min in a windless condition at -10 degrees C. Meanwhile, the composites exhibited stable resistivity and good self-heating repeatability as well as temperature homogeneity during the self-heating process. The SSWs-modified asphalt concrete slab could melt a 4 mm ice layer within 2 h with an energy efficiency as high as 88.59% at the voltage of 60 V, and the cooling residual heat could theoretically melt a 2.4 mm ice layer to improve the self-deicing energy efficiency by 15.21%. Therefore, the low content SSWs-modified asphalt concrete exhibits promising application prospects in self-deicing pavement.