- Volume 18 Issue 6
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Applicability Estimation of Ballast Non-exchange-type Quick-hardening Track Using a Layer Separation Pouring Method
층 분리주입을 이용한 도상자갈 무교환방식 급속경화궤도의 적용성 평가
Lee, Il Wha;Jung, Young Ho;Lee, Min Soo
- Received : 2015.08.13
- Accepted : 2015.10.19
- Published : 2015.12.31
Quick-hardening track (QHT) is a construction method which is used to change from old ballast track to concrete track. Sufficient time for construction is important, as the construction should be done during operational breaks at night. Most of the time is spent on exchanging the ballast layer. If it is possible to apply the ballast non-exchange type of quick-hardening track, it would be more effective to reduce the construction time and costs. In this paper, pouring materials with high permeability are suggested and a construction method involving a layer separation pouring process considering the void condition is introduced in order to develop ballast non-exchange type of QHT. The separate pouring method can secure the required strength because optimized materials are poured into the upper layer and the lower layer for each void ratio condition. To ensure this process, a rheology analysis was conducted on the design of the pouring materials according to aggregate size, the aggregate distribution, the void ratio, the void size, the tortuosity and the permeability. A polymer series was used as the pouring material of the lower layer to secure the void filling capacity and for adhesion to the fine-grained layer. In addition, magnesium-phosphate ceramic (MPC) was used as the pouring material of the upper layer to secure the void-filling capacity and for adhesion of the coarse-grained layer. As a result of a mechanics test of the materials, satisfactory performance corresponding to existing quick-hardening track was noted.
Quick hardening track;Ballast;Non-exchanging type;Track structure improvement;Void ratio
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Supported by : 국토교통부