Research on the segregation and mechanical properties of epoxy asphalt concrete under the condition of train vibration in road-railway bridge

Abstract

In the reconstruction of the road-railway bridge (RRB), the train-induced vibration would lead to segregation and other performance changes in the asphalt mixture in the paving process. This paper aims to investigate the segregation phenomenon and Marshall stability (MS) change of epoxy asphalt concrete (EAC) considering vibration excitation. The typical train-induced vibration condition (TVC) on the road bridges was obtained by in-situ monitoring. Subsequently, self-designed vibration tests were conducted to assess the segregation of EAC, which was statistically analyzed using a T-test. The evolutions of MS with TSTs (the index of segregation test) were analyzed. Results indicate that segregation induced by train-vibration increases with the vibration duration until reaching a threshold of 20 s. The TST grows with vibration frequency and declines after reaching a peak value where the frequency is 16 Hz. In addition, the vibration mainly affects the initial MS of EAC by altering the homogeneity of asphalt concretes, while the ultimate MS of EAC which consisted of chemical reaction was almost unaffected. Three typical stages of vibration effects were identified and the solutions of each were given. The output has been adopted to the Jiujiang Yangtze River RRB reconstruction project which has been in service for 5 years.