FORMATION METHOD OF HOLLOW SECTION IN CONCRETE CONSTRUCTION

摘要

PURPOSE:To form a hollow section having a free shape in a concrete construction easily, non-destructively and at a low cost so that a form is not left over. CONSTITUTION:A water absorption expansive material 10 expanded with water absorption is used as a form, concrete 12 is placed around the form, the concrete is cured and dried, and after the water absorption expansive material in the concrete is dried and contracted, the dried and contracted water absorption expansive material 14 is removed from the concrete to form a hollow section 16. The water absorption expansive material is so formed that a water absorption expansive high-molecular compound is mixed with rubber or soft resin.