Development and Application of Cross-Section Repair Method for Culvert Tunnels of Metropolitan Railways
By A. Hirayama, K. Fukui, Y. Kawabata and T. Yamagishi
Concrete Journal, Vol.54, No.2, Feb. 2016
- Synopsis
- The rational maintenance of the large number of concrete structures built during Japan's period of high economic growth is becoming necessary, and the concrete degradation of railway tunnels such as subway tunnels has become an issue. As cross-section repair of railway tunnels can take place only at night when train service stops, the time period from repair work completion to service start is short. Thus, cross-sectional repair materials must provide good strength development and reliable workability. This report describes laboratory and field experiments for the application of a cross-sectional repair method that sprays freshly mixed mortar to which curing accelerator has been added for the repair of railway tunnels, and reports the recorded improvement in strength development of the cross-section repair material at early ages. Through the appropriate combination of quick hardening material and curing accelerator, the developed cross-section repair method secures trowel finishing time of 15 minutes, and compressive strength exceeding 5N/mm2 after 3 hours was recorded.
- Keywords:
- cross-section repair method, railway tunnel, culvert tunnel, spraying, curing accelerator, quick hardening material
