Compressive Strain Characteristics of Asphalt Mixtures under Viscoelastic State at Normal Temperature

To quantitatively analyze the compressive strain characteristics of asphalt mixtures with different structures under viscoelastic state at normal temperature, the digital speckle correlation method was used to obtain the entire loading process images of asphalt mixtures under uniaxial compression mode. The strain field of asphalt mixtures under load was calculated and visualized, and indicators such as mean strain, probability of relative strain strength, and proportion of high strain were proposed. The relationship between the structural characteristics and the evolution of the strain distribution was established. The results indicate that under the viscoelastic state at normal temperature, the role of the skeleton is limited, and the failure mode of uniaxial compression is shear failure. The stress transmission capacity of asphalt mixtures can be characterized by the mean strain. Both the evolution amplitude and rate of the vertical strain are greater than those of the horizontal strain. The proportion of high strain can reflect the degree and extent of damage, and the structural design of the asphalt mixtures can be optimized by means of the strain characteristics.