| 摘要 |
<p>A flexible form member according to the invention comprises a hollow-shaped body having a flexibility and openable fluid introducing and discharging means for permitting fluid to be introduced into and discharged from the body. A method of forming a through hole by means of the flexible form member comprises placing the flexible form member as contracted in a desired position between an outer form and an inner form, introducing fluid into the flexible form member to expand it between the outer form and the inner form, pouring concrete, removing the forms and contracting the flexible form member after curing of concrete, and removing the flexible form member thus contracted from concrete.</p> |
