Factors affecting the rutting resistance of asphalt pavement based on the field cores using multi-sequenced repeated loading test

Abstract

Rutting or permanent deformation is one of the main failure modes in hot mix asphalt (HMA) pavement. Since laboratory-produced specimens could hardly reflect the actual compaction condition and material properties of asphalt mixtures in the field, it is necessary to evaluate rutting resistance in situ pavement conditions based on field cores. In this study, field cores of 30 different road sections were collected from 7 different highways in Jiangsu Province, China. A newly developed multi-sequenced repeated load (MSRL) test by Southeast University was conducted on both full-depth specimens and separated layers considering the actual load-axle spectrum and temperature gradient in the corresponding sections. A new indicator, Compound Strain Rate (εc), which indicates the deformation rate of asphalt mixtures under the actual load-axle spectrum, was proposed to evaluate the rutting-resistant of different field materials. Then, statistical evaluation including distribution analysis and Analysis of Variance (ANOVA) were conducted on the test results. According to the analysis of the correlation between εc of full-depth specimens with samples from different layers, the rutting resistance of the middle layer presents the most significant influence on the high-temperature stability of the full-depth pavement structure. In terms of material factors, binder type exhibits a significant effect on the rutting resistance of all layers while gradations only influence the results of the top layer. Considering the external factors, both road age and the accumulative number of equivalent single axle loads (ESAL) could influence the rutting resistance of different field materials, especially, the εc of materials from the middle layer. Moreover, the influence of material factors on permanent deformation performance of asphalt pavement under different traffic loads was analyzed.