| 摘要 |
PURPOSE: To increase strength by tightening ends of steel materials, which protrude from both ends of embedded formworks in very close juxtaposition, by a tighed bar, placing curing and hardening concrete on its top surface, and the removing the tighed bar. CONSTITUTION: After a steel material is arranged in the inside of a formwork whose bottom section rises upward in the arch shape, concrete is placed, cured and hardened to form an embedded frame 5 in which ends of the steel material protrude from both ends thereof. Next, the embedded formworks 5 are arranged in parallel in close contact mutually, and the ends 6 of the steel material are provided in a condition in which they are in tension sufficiently by a tighed bar 7. Then, concrete 8 for bottom system is placed in an upper part of the embedded frame 5 and cured and hardened. After the strength of the concrete 8 for bottom system appears sufficiently, the tighed bar 7 is removed from the embedded frame 5 to release the tension of the embedded frame 5 so as to form a floor system 9 for road, track, etc. |
