摘要 |
A shrinkable core (100) for inserting in a mold (200) for forming a precast load bearing wall panel having a cavity, the shrinkable core (100) comprises a first wall (110) and a second wall (120), a first side element (112) and a second side element (122), and a spacing element (130). The first wall (110) and second wall (120) are spaced from to each other by a first distance (dl) to define an internal region (115) in-between. The first side element (1 12) and the second side element (122) are arranged to close opposite edge portions of the spaced first wall (110) and second wall (120) such that fluid concrete cannot pass the opposite edge portions to get into the internal region (115), the first side element (112) and second side element (122) being spaced by a second distance (d2). The spacing element (130) is configured to vary at least one of the first distance (dl) and the second distance (d2) such that a circumference along the first and second walls (110, 120) and the first and second side elements (112, 122) shrinks monotonically with lowering said at least one distance. |