Study on the influence factors of fatigue properties of large-stone asphalt mixtures based on semi-circular bending tests

Abstract

In order to alleviate the fatigue cracking problem of asphalt pavements. The development of large-stone asphalt mixtures (LSAM) is a worthwhile research direction. In this paper, different loading frequencies, test temperatures and stress ratios are designed to investigate the influence of semicircular bending (SCB) test conditions for LSAM fatigue properties. Comparative tests were also conducted with AC-13 fine-grained asphalt mixtures. The fatigue property of LSAM was analyzed by applying Paris' law, measuring fatigue crack length and using fatigue rupture energy theory. The test results indicated that fatigue life increased approximately 12 times with increasing loading frequency, 5 times with lower test temperatures, and 4 times with reduced stress ratio. Respectively, the magnitude of the single fatigue rupture energy and the total fatigue rupture energy also increased. Compared to AC-13 fine-grained asphalt mixtures, LSAM has a lower rate of rise in the displacement curve and smaller fracture displacement. After logarithmic transformation, the fatigue rupture energy and fatigue life of LSAM show an obvious linear relationship, specifically Wf=0.000806Nf1.12975. In summary, based on the SCB test conditions, LSAM exhibited superior fatigue performance compared to AC-13 fine-grained asphalt mixture. Additionally, LSAM demonstrated better resistance to fatigue loading-induced deformation.