The flexible base asphalt pavement is characterized by its excellent performance. A critical component of this structure is the connected layer, which links the surface layer to the flexible base. This layer is located in an area of high-pressure stress distribution within the pavement. The risk of rutting is heightened in the connected layer due to the effects of loads and temperature fluctuations. However, existing studies have not established a correlation between temperature and rutting prediction models for connected layer materials. Therefore, this study aims to accurately characterize the temperature dependence of the rutting behavior of these materials. Firstly, variations in dynamic stability and rutting deformation of connected layer mixtures were investigated under different temperatures and asphalt binder types. Subsequently, a temperature-dependent model of rutting behavior was developed, highlighting the influence of varying temperatures and asphalt binder types. The proposed temperature-dependent rutting model addresses the limitations of traditional models, which fail to accurately describe the rutting behavior of materials under complex working conditions, and provides a scientific basis for optimizing asphalt pavement design and enhancing rutting performance.

Traditional laboratory rutting tests are performed at a constant temperature by neglecting pavement temperature variation. The mechanical properties of asphalt are susceptible to temperature variation. This sensitivity to temperature variations significantly influences the performance and durability of asphalt pavements. Following this purpose, a stepwise temperature-controlled rutting test method was proposed to investigate the rutting development of double-layer asphalt pavement (DLAP) under variable temperature. A time-hardening model was developed and employed to evaluate the rutting performance of DLAP under variable temperature. Results indicate that the rutting development of DLAP exhibits a stepwise variation when subjected to variable temperatures. Within a specific constant temperature range, rutting development can be fitted using a power function of load cycles. The rutting deformation of DLAP predominantly occurs at 20 °C; once the temperature exceeds 50 °C, the rutting development accelerates and becomes difficult to stabilize. The time-hardening model effectively captures the rutting development under variable temperature. The predicted values align closely with field values, which demonstrates the model’s feasibility in calculating rutting deformation under variable temperature. Under actual service conditions, the rutting development of DLAP follows a periodic S-shaped growth, yet this trend can still be represented by a power-law function. DLAP exhibits satisfactory durability and structural stability, effectively addressing the challenges posed by traffic loads and high temperatures in test sections.