Effect of long-term aging on the fatigue properties of aramid fibres reinforced asphalt mixture

ABSTRACTABSTRACTSynthetic fibres have been reported to provide substantial improvements to the mechanical properties of asphalt mixture. This study investigates the impact of aging on the cracking of aramid fibre-reinforced asphalt mixes (AFM) using the simplified viscoelastic continuum damage (S-VECD) theory. Loose asphalt mixtures with 0.05% fibre and control loose asphalt mixes were placed in an oven for 0, 1, 2, 4, and 7 days, respectively. Then, the viscoelastic properties and cracking behaviour of hot mix asphalt (HMA) and AFM were evaluated and compared using the dynamic modulus test and fatigue tests. The test results showed that the difference in the AMR (aging modulus ratio) values increased as the decrease in frequencies and temperatures increased. The aging sensitivity of the AFM was lower than the HMA after the 7d aging condition. The AMR is negatively correlated with the Sapp value which indicates fatigue cracking deterioration and modulus damage are correlated negatively during aging durations. The reductions in fatigue cracking performance of the AFM were 5%, 8%, 20%, and 23% subjected to 1d, 2d, 4d, and 7d aging conditions, which demonstrates the 4d aging condition is the key cracking stage during the aging durations. This study provides a reference for evaluating the anti-cracking performance of AFM under different aging conditions, which can be beneficial to aramid fibre asphalt pavement design and maintenance.KEYWORDS: Road engineeringasphalt mixturefatigue crackinglong-term agingaramid fibre AcknowledgementsThis project was supported by Key Research and Development Project of Shaanxi Province (2022GY-427) and the first author also gratefully acknowledges the financial support from China Scholarship Council (202006560071). This paper acknowledged the NCSU Asphalt Materials Lab for access to facilities for testing.Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis project was supported by Key Research and Development Project of Shaanxi Province (2022GY-427) and the first author financially supported by China Scholarship Council (202006560071).