Indirect Tensile Test as a Simple Method for Rut Resistance Evaluation of Asphalt Concrete

The paper presents the dependence of ITS results at the elevated temperature (40°C) on rutting parameters, i.e. proportional rut depth (PRD_AIR) and wheel tracking speed (WTS_AIR), obtained at the temperature of 60°C. The asphalt mixture samples were prepared in the gyratory compactor, but ITS tests were conducted with typical Marshall press, at a loading rate of 50 mm/min. Correlation analyses show a strong relationships between ITS results and rutting parameters, whereby the correlation coefficients obtained are higher for the PRD_AIRparameter (r = −0.88) than WTS_AIR(r = −0.81). Using the obtained regression functions, the prediction limits as well as confidence limits were calculated, which allowed to develop criteria for assessing resistance to rutting on the basis of ITS test, and taking into account the technical requirements in Poland.