| 摘要 |
PROBLEM TO BE SOLVED: To suppress a temperature rise in a sheath due to a temperature rise in surrounding concrete 2 at a time of early tensioning of a PC cable 1, and to secure necessary remnant wall thickness of the sheath.SOLUTION: A configuration method for a cable 1 inside a PC uses a plastic sheath 5 arranged in a building frame 2 of a pre-stressed concrete structure, the plastic sheath having a curved part R and a straight part. A PC steel material 6, the sheath and concrete surrounding the sheath are cooled by sending chilled air W into the sheath, before tensioning, during tensioning, and after tensioning until a temperature of the concrete around the sheath drops to a prescribed temperature. The configuration suppresses sheath softening, therefore reducing an amount of wear and a recessed amount of a sheath wall 9, which are caused by sliding inside the sheath 5 due to deflection pressure q and tensile elongation P generated due to an increase in tensile force of the PC steel material 6 at the curved part R of the cable, when tension is applied to the PC steel material 6 under a high-temperature condition caused by a construction work condition under a high outdoor temperature or hydration reaction heat of concrete. As a result, a necessary remnant wall thickness of the sheath is secured.SELECTED DRAWING: Figure 1 |
