| 摘要 |
PURPOSE: A precast concrete manhole and a mold thereof are provided to improve water-tightness by using packing and concrete mortar. CONSTITUTION: A precast concrete manhole comprises a flow pipe(10), an auxiliary pipe(20), a packing(30), concrete mortar, a ring nut(40), and a traction hook(45). A flow pipe is coupled on the lower end of a circular concrete manhole(100). The flow pipe is formed for the flow of the sewage. The auxiliary pipe is molded on the bottom of the manhole in hardening the concrete manhole. The packing is inserted into an outermost groove(104) and a first groove(101) formed at the upper end of the manhole. The concrete mortar is poured in two central grooves(102,103) formed on the upper end of the concrete manhole. The ring nut is molded on the both left and right sides of the concrete manhole during the hardening of the concrete manhole. The traction hook comprises a screw portion(42) and a hook portion(44). A screw part is coupled on the nut part(41). |
