Method of producing concrete elements

Claim 1

A method of manufacturing a slab-form concrete element having a predetermined nominal thickness between mutually parallel upper and lower sides and containing at least one essentially flat filling body with a thickness, wherein a first part, of the element, which contains said at least one filling body is cast, in a first mould, in a first manufacturing stage and allowed to harden, and wherein said first part, when hardened, is turned upside down and lowered into a second mould, which contains an amount of fresh concrete, in a second manufacturing stage and the fresh concrete is allowed to harden, the improvement in the method comprising: in the first manufacturing stage, pouring a first quantity of concrete into the first mould, after said at least one filling body is placed in the first mould to a level such that an upwardly facing side of said at least one filling body, when in said first mould, is above and free from said first quantity of concrete and permitting said first quantity of concrete, which includes said at least one filling body, to harden to thereby become the first part of the concrete element, wherein said upwardly facing side of said at least one filling body is provided with recesses whose combined volumes of space corresponds to a variation in the amount of fresh concrete used in the second manufacturing stage such that the recesses accommodate the variation in the amount of fresh concrete in the second mould to provide the concrete element with the predetermined nominal thickness; and including in the second manufacturing stage, the steps, after the first quantity of concrete has hardened, of inverting and lowering said first part, into the second mould containing the fresh concrete, to a level at which the concrete element is formed with the predetermined nominal thickness between its upper and lower sides due to the recesses provided on the at least one filling body accommodating the variation in the amount of fresh concrete used in the second manufacturing stage.

Claim 2

A method of manufacturing a slab-form concrete element having a predetermined nominal thickness between mutually parallel upper and lower sides and containing at least one essentially flat filling body with a thickness, wherein a first part, of the element, which contains said at least one filling body is cast, in a first mould, in a first manufacturing stage and allowed to harden, and wherein said first part, when hardened, is turned upside down and lowered into a second mould, which contains an amount of fresh concrete, in a second manufacturing stage and the fresh concrete is allowed to harden, the improvement in the method comprising: in the first manufacturing stage, pouring a first quantity of concrete into the first mould, after said at least one filling body is placed in the first mould to a level such that an upwardly facing side of said at least one filling body, when in said first mould, is above and free from said first quantity of concrete and permitting said first quantity of concrete, which includes said at least one filling body, to harden to thereby become the first part of the concrete element, wherein said upwardly facing side of said at least one filling body is provided with recesses whose combined volumes of space corresponds to a variation in the amount of fresh concrete used in the second manufacturing stage such that the recesses accommodate the variation in the amount of fresh concrete in the second mould to provide the concrete element with the predetermined nominal thickness; and including in the second manufacturing stage, the steps, after the first quantity of concrete has hardened, of inverting and lowering said first part, into the second mould containing the fresh concrete, to a level at which the concrete element is formed with the predetermined nominal thickness between its upper and lower sides due to the recesses provided on the at least one filling body accommodating the variation in the amount of fresh concrete used in the second manufacturing stage.