New Asphalt Concrete Rutting Resistance Evaluation Method Based on Repeated-Load Test

AbstractRutting of asphalt pavement is the accumulation of plastic deformations and is one of its major distresses and concerns. To date, rutting of asphalt pavement cannot be accurately predicted because of the complex material behavior. The repeated-load test was deemed to be a good method for asphalt concrete rutting analysis. In this paper, the strain recovery characteristic of the asphalt mixture is studied to reflect material rutting resistance based on the repeated-load test. Fiber Bragg grating-based three-dimensional (3D) strain measurement equipment was used to synchronously measure the vertical and lateral strain of the test specimen. The rutting resistance evaluation method was demonstrated through an analysis of the repeated-load test data of four types of asphalt mixtures with nanosized volcanic ash fine fillers. A new phase angle calculation model was developed, and the calculated strain curve based on this model coincides well with the test data. The calculated phase angle of the asphalt mixtures used in this paper is two times larger than that obtained from the traditional direct curve comparison method. A new indicator, the ratio of residual strain (RRS), which is not influenced by the aggregate skeleton, was used for the rutting resistance evaluation of all of the materials. The mechanism of the generation of plastic deformation was also analyzed based on the test data.