Normalized fatigue properties of asphalt mixture at various temperatures

This study normalized the mixture's fatigue behavior at various temperatures, and the strength and fatigue tests of the mixture were conducted. The stress state of the asphalt mixture includes direct tensile, uniaxial compression, and indirect tensile. The Desai yield surface and fatigue path were proposed. And a normalized fatigue characteristics model of the mixture was established. The following conclusions were obtained. With the increases in the loading rate, the strength of the asphalt mixture increased. As the temperature increases, the strength of the mixture is reduced. At various temperatures and rates, the strength forms a closed curved surface. The Desai strength yield surface was established, which forms a closed curved surface. When the loading rate and temperature are below a certain critical line, the asphalt mixture will not undergo strength damage. At a fixed stress state, the fatigue damage path of the mixture was determined. The stress ratio was determined considering the influence of the loading rate. In this way, a normalized model can be described to express the asphalt mixture fatigue properties at various temperatures and stress levels. For the asphalt mixture in an indirect tensile state, the normalized fatigue equation parameter is 4.09. This model is more suitable for reflecting the viscous-elastic behavior of the mixtures than the fatigue equation determined by the notional stress ratio.