| 摘要 |
PURPOSE:To prevent the occurrence of internal stress in concrete during the curing period of the concrete by a method in which a box is enclosed with a temporary cover, a gas or liquid is sent into the inside of the box, and a lifting pressure balancing the pressure of a top slab concrete is adjusted by operating a cock and controlling the height of the head. CONSTITUTION:When a liquid is used as a pressure medium, water passing through a water supply pipe 3 and whose flow rate is adjusted by a cock 4 is directed into a box 1, and the water W filling up the box 1 passes through the horizontal portion 6 of a drain pipe 5 provided beneath the upper enclosed type temporary cover of the box 1, goes up a rising portion 8, and goes out of an outlet port 14. The upper loading pressure is properly balanced with the lifting pressure under a proper control in order to prevent the occurrence of internal stress in the concrete during the curing period of the concrete. |
