Influence of volumetric properties of asphalt samples on the electrical resistivity characteristics

Low temperatures caused by weather conditions lead to the occurrence of thermal strain due to the contraction of hot-mix asphalt HMA). A fall in outside air temperature can lead to the freezing of salt water in voids resulting from the melting of snow and the salting of roads during winter maintenance. In connection with this, the current paper presents tests conducted on the electrical resistivity value of Marshall samples made of HMA with the aim of achieving a potential increase in heat of saturated asphalt layers during the winter period. The goal of the research was to determine the specific electrical resistivity of asphalt samples of varying compositions under changing test conditions. In total, for the testing purpose, 52 asphalt mixtures of varying compositions were prepared and exposed to changing laboratory conditions. During the testing, the electrical resistivity of asphalt samples which were immersed in water of variable salinity (0%, 10%, 20% and 30%) was examined. The main results indicate that an increase in the content of dissolved salt in a solution leads to a significant increase in the conductivity of the asphalt samples. The results of the mentioned relationships show that the value of electrical resistivity is affected more by the connectivity and form of the content of the air void than by the amount. The conducted tests lead to achieving a functional relationship among the observed properties of asphalt samples, solution salinity content and specific electrical resistivity.