Core for use in casting hollow concrete slab and method of casting such slab

摘要

There is disclosed a core for use in casting a long concrete slab for forming a continuous hole extending alnog its length. The core comprises a relatively rigid, resilient elongated hollow body having closed opposite ends, and a contractible filling member made of an open-cell foamed material and filled in said hollow body. Also disclosed is a method of casting a long hollow concrete slab, using a core having the construction as aforesaid.