Thermal fatigue is a serious distress in flexible pavement that reduces performance and durability. Many researchers have made efforts to understand the thermal fatigue phenomenology. Until now, there has not existed a standard test method for evaluating mixture and binder resistance to thermal fatigue. The bitumen binder is the first factor that participates in the degradation of asphalt concrete. The objective of this study was to contribute to characterizing the EVA polymer modified bitumen, which was subjected to thermal fatigue. The aim of this work is to determine the rheological components and their evolutions under thermal fatigue with heating-cooling cycles. The results suggest that thermal fatigue has more complicated effects on the rheological behavior of modified bitumen. It is concluded that thermal fatigue due to thermal cycling with aging is a major component in accelerating the degradation of pavement.

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Conductive asphalt concrete can satisfy different and multifunctional applications such as heating roads to get rid of snow and ice and assure auto-detection, auto-cure, and energy recovery. This research aims to evaluate the performance of asphalt concrete with additives like steel fibers and graphite powder. This work is based on destructive tests (direct tensile test FENIX) and non-destructive tests (electrical resistivity measures). The obtained results indicate that the tensile resistance, dissipated energy, and ductility module of asphalt concrete increased with the increasing steel fiber percentage. Direct tensile strength, cracking resistance, and dissipated energy increased as graphite percentage increased, while the ductility module decreased. Electrical resistivity decreased when it added steel fibers and graphite. Therefore, it found that tensile strength increased reversibly with electrical resistance. When adding steel fibers or graphite powder, the dissipated energy of asphalt concrete is increased while electrical resistivity is decreased. The dissipated energy of conductive asphalt concrete with steel fibers is higher than that with graphite powder. Electrical resistivity decreased significantly with increasing steel fibers, compared to electrical resistivity with graphite. The obtained results indicate that asphalt concrete cracking resistance is higher with the optimal percentage of steel fibers added at 1% and better mechanical performance. Doi: 10.28991/CEJ-2022-08-02-012 Full Text: PDF

This research is devoted on the study of creep behavior of asphalt binder in hot region. This binder was subjected to thermal cycles due to the variation of temperature from day to night. These cycles produce a heating-cooling phenomenon. To evaluate the effect of climate change in laboratory, it was used the rheometer DSR, and compare the results found with the nine sample. These thermal cycles led to aging and therefore hardening of the binder. Thus, the proposal of a rheological model that can represent the curves obtained experimentally, where it is able to describe the creep behavior of binders tested. It is proposed a new model that correlates well with the experimental curves, it is called A+2K.