Investigation of the deformation properties of asphalt mixtures with DIC technique

It is hardly to address the mechanical behavior with the classic measurement techniques accurately, which is very important for asphalt mixture and pavement deign. To obtain more experimental information of the asphalt mixture failure processes to improve the identification procedures for this type of material, DIC technique and IDT test are employed in this study. It is found that the information obtained by DIC system is very useful to investigate the deformation and fracture propertied accurately. It is also found that the distribution of aggregate and asphalt mortar will affect the distribution of strains because the module difference between aggregate and asphalt mortar. So the appropriate length of analysis should be determined to achieve the required accuracy and increase computational efficiency; the Poisson’s ratio of asphalt mixture under 25 °C is not a constant, which is effected by load and gyratory compaction times. And because the formulas for calculating strain suggested in Chinese specification are introduced by the linear elasticity theory, and Poisson’s ratio is a constant, it is not appropriate for the calculation of horizontal deformation, especially in the larger stress conditions.

► The horizontal strains obtained by elastic solution and DIC system are different. ► Determine appropriate analysis length to ensure accuracy and efficiency. ► Asphalt mixture Poisson’s ratio under 25 °C is not a constant. ► Strain calculating formulas suggested in Chinese specification are not appropriate.