Investigation on the Performance of Railway Ballast Track Stabilized by Cement Asphalt Mortar

초록

Under tremendous transportation services, the exhausted track irregularities and ballast deterioration lead to the vast increment in railway track-bed maintenance costs annually. This research aims to develop new material to reinforce the performance of high-speed railway track-bed. The unique characteristic of this cement asphalt mortar (CAM) mixture is to incorporate the flexibility of bitumen and the strong resilient modulus of cement hydration products. From different cement (C) and asphalt emulsion (AE) ratios, the dynamic modulus, and indirect tension tests are conducted to investigate the engineering properties of CAM mixtures at hardened stages. The scanning electron microscope (SEM) analysis is employed to determine the micro connection between asphalt membrane and the hydrated cement particles. Then, the actual dynamic response of CAM is verified through a full-scale testbed application. From the test results, it is found that the AE/C ratio imposes a substantial effect on the characteristic of CAM. The usage of high cement content not only leads to the stronger dynamic stiffness but also contributes to the lower temperature and frequency dependence of CAM mixtures. Meanwhiles, the viscous-elastic behavior of CAM is prominent when using high AE levels. Overall, the laboratory and full-scale tests results suggest that the connection between CAM and ballast particles can substantially enhance the durability of railway structure, indicating a better operation of high-speed railway and stronger track foundation for sustainability development purposes.