Patent ID: 7669333

Claim:
A method for coupling concrete parts, comprising the steps of: providing a formwork, said formwork including an inner side; placing a plurality of bodies against said inner side of said formwork, each of said bodies having a shape and including an elastomer material, each body being configured such that when a tensile force is applied to said body, a diameter of said body is reduced; pouring and at least partially setting concrete material about said formwork and said bodies so as to form a first concrete part having a plurality of cavities formed therein, each cavity having a shape at least partially corresponding to the shape of one of said bodies and extending from an outer wall of said first concrete part, wherein the elastomer material of each of said bodies adjoins concrete material and then each of said bodies can be removed from said cavities by applying a tensile force to each of said bodies at the outer wall of said first concrete part; detaching said formwork and said bodies from said first concrete part; providing metal reinforcing bars which are receivable within the cavities in said first concrete part; and securing said reinforcing bars in said cavities, said securing step including filling a space within each cavity between said metal reinforcing bars and said first concrete part with a material which bonds to said reinforcing bars and to said first concrete part, said metal reinforcing bars being encased in the concrete of a second concrete part.