Interpreting the creep behavior of asphalt mortar at high temperature through experimental and numerical methods

•The high temperature creep behavior of three asphalt mortars was investigated.•The adhesion of asphalt mortar is the main factor for its compressive strength.•The creep of three mortars was tested at different stress levels and temperature.•The Burgers model can be modeled as the creep behavior of asphalt mortar. Rutting or permanent deformation is a major distress for asphalt pavement structures that are subjected to heavy traffic loadings. In this study an experimental study was conducted to evaluate the creep characteristics of asphalt mortar at elevated temperatures. The compressive strength of three types of asphalt mortar gradations used in airfield pavement were tested by the uniaxial compression test at 40 °C, 50 °C and 60 °C. In addition, triaxial creep test was used to test the creep of the three mortars at stress levels of 100 kPa, 300 kPa and 500 kPa. After that, the Burgers model and the modified Burgers model were chosen to simulate the creep curves. Viscoelastic fitting analysis results shown that the correlation R2-value of the two models were found to be greater than 0.95 at each stress level, the Burgers model has an R2 more than 0.98. it indicated that the Burgers model can better describe the creep characteristics of the asphalt mortar under repeated loadings.