저심도 구조체용 콘크리트 재료 개발 방향

Near-surface transit system is constructed 5~7m below the road by open-cut method. Through the rapid construction of underground structures, road traffic congestion and lane encroachment should be minimized. To shorten construction period, underground structures need to be constructed precast concrete structures instead of cast-in-place concrete structures. In order to minimize road lane encroachment, the weight of precast concrete structures , which make possible to use light-weight crane machine, should be lessen. For this reason, eco-friendly lightweight concrete for manufacturing precast structures has been developing in research. In this paper, authors investigated and analyzed the recent research trend on the ecofriendly and lightweight concrete materials, and then described development directions of concrete materials of precast underground structures for near-surface transit.