Method and apparatus for casting prefabricated concrete products

Abstract

Method and apparatus for casting prefabricated concrete products with a substantially horizontal slipform casting process, where the concrete mass is fed in at least one feeding stage to a slipform casting mold compacting and defining the product to be cast, wherein at least one part is embedded in the concrete mass after the at least one concrete mass feeding stage and before the final compaction of the upper surface of the product to be cast.

Claims

1. A method for casting prefabricated concrete products with a substantially horizontal slipform casting process, where the concrete mass is fed in at least one feeding stage to a slipform casting mold compacting and defining the product to be cast, wherein at least one part is embedded in the concrete mass via the upper surface of the product to be cast after the at least one concrete mass feeding stage and before the final compaction of the upper surface of the product to be cast.

2. The method according to claim 1, wherein the at least one part is embedded only partially in the concrete mass and passes through the slipform casting mold through a gap in the top surface of the slipform casting mold.

3. The method according to claim 1, wherein the at least one part is a reinforcement bar, a lifting loop forming part, a fixing part for a parapet, a fixing part for a bracing utilized during installation of the concrete product, a fixing part for safety gear, or a bushing with inside thread.

4. The method according to claim 1, wherein the concrete product is a hollow-core slab, and the at least one part is embedded in the area of the webs between hollow cores.

5. The method according to claim 1, wherein the at least one part is embedded in the longitudinal end area of the product to be cast.

6. The method according to claim 1, wherein the method is extruder-type or slipformer-type slipform casting method.

7. An apparatus for casting prefabricated concrete products with a substantially horizontal slipform casting process, wherein the apparatus comprises devices for feeding concrete mass in at least one feeding stage to a slipform casting mold compacting and defining the product to be cast, wherein the apparatus comprises devices for embedding at least one part in the concrete mass via the upper surface of the concrete product to be cast after the at least one concrete mass feeding stage and before the top surface of the slipform casting mold compacting the upper surface of the product to be cast.

8. The apparatus according to claim 7, wherein the slipform casting mold comprises a top surface divided in sections, between which sections is provided a gap for allowing a partially embedded part to pass through the slipform casting mold.

9. The apparatus according to claim 7, wherein the apparatus comprises hollow-core forming devices.

10. The apparatus according to claim 7, wherein the embedding direction of the device for embedding the at least one part in the concrete mass is adjustable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 shows schematically an embodiment of the apparatus of the invention,

[0027] FIG. 2 shows schematically an alternative embodiment of the apparatus of the invention,

[0028] FIG. 3 shows schematically an embodiment of the embedding device for an apparatus of the invention, and

[0029] FIGS. 4A-4D show schematically examples of the parts to be embedded to a concrete product with the apparatus of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0030] In FIG. 1 is shown an embodiment of the apparatus of the invention, which apparatus in this embodiment is an extruder-type slipform casting machine 1. The casting machine 1 comprises a concrete mass tank 2, from which the concrete mass is fed to feed screws 3 extruding the concrete mass into a slipform casting mold formed by casting bed 4, side plates 5 and a top compaction beam 6. When casting hollow-core slabs (HCS) the feed screws 3 are followed by hollow-core forming mandrels 11. The casting machine 1 moves along the casting bed 4 via rails 7 with wheels 8, propelled by the reaction force of the feed screws 3 with help of drive machinery (not shown) in the direction of the arrow.

[0031] The casting machine 1 comprises an embedding device 9 for embedding parts 10 into the concrete product to be cast. The position of the embedding device 9 can be adjusted by tilting it in relation to the casting machine 1, so that the orientation of the embedded parts 10 may be adjusted in the concrete product to be cast. This tilting preferably takes place around a tilting axis extending horizontally perpendicularly in relation to the casting direction. This allows the embedding of the parts 10 in different positions in a one and same concrete product to be cast by tilting the embedding device 9 during the casting process, such as when casting end reinforced concrete slabs where the angle of the embedded parts is opposite at different ends of the slab, for example. In this solution the tilting of the embedding device can be implemented to be dependent on the position of the casting machine 1 or on the casting distance, for example. The operation and construction of the shown embodiment of the embedding device 9 will be discussed in more detail later in relation to FIG. 3.

[0032] In order to allow the upper ends of the embedded parts 10 extending above the upper surface of the product to be cast to pass the slipform casting mold, the top compaction beam 6 is formed in sections with gaps between the sections extending in the casting direction through the area of the compaction surface of the beam at the locations of the embedded parts.

[0033] In FIG. 2 is shown an alternative embodiment of the apparatus of the invention, which apparatus in this embodiment is a slipformer-type slipform casting machine 21. In this embodiment the concrete mass is fed into the slipform casting mold in two feeding stages, in the first feeding stage via feed hopper 22, and in the second feeding stage via feed hopper 23. The casting machine 21 moves along the casting bed via rails propelled with drive machinery in the direction of the arrow in the figure.

[0034] The casting machine 21 comprises an embedding device 24 for embedding parts 25 into the concrete product to be cast. In this embodiment the embedding takes place after the first concrete mass feeding stage and before the second concrete mass feeding stage. The embedding device 24 is advantageously fixed to the casting machine 21 turnably, so that the orientation of the embedded parts 25 may be adjusted in the concrete product to be cast, such as discussed in relation to the embodiment of FIG. 1.

[0035] In this embodiment the top surface of the slipform casting mold is also advantageously divided into sections so that when parts 25 are only partially embedded in the product to be cast the portions of the parts extending from the upper surface of the product to be cast can pass through the slipform casting mold.

[0036] FIG. 3 shows schematically an embodiment of the embedding device 9, 24 of the invention. In this embodiment the embedding device 9, 24 comprises three main sections: magazine 31, feeding section 32 and embedding section 33.

[0037] The magazine 31 is used to store a plurality of parts to be embedded in the product to be cast, and is equipped with means 34 for feeding the parts one by one into the feeding section 32. The means 34 can be implemented with a suitable conveyer belt, for example.

[0038] Once the part is fed from the magazine 31 into the feeding section 32, it is transferred with transfer means 35 to the embedding section 33. The transfer means 35 can be implemented with a pusher moved with a hydraulic cylinder, for example.

[0039] The part located in the embedding section 33 is then pushed out of the embedding device 9,24 and embedded in the product to be cast at suitable place and to the suitable depth with embedding means 36. These embedding means 36 can be implemented with a pusher moved with a hydraulic cylinder, for example.

[0040] The operation of the embedding device 9, 24 is also advantageously controlled by an automatic control system controlling the casting process of the slipform casting machine 1, 21. This enhances the correct positioning of the parts embedded in the product to be cast.

[0041] FIGS. 4A-4B show schematically examples of the parts to be embedded to a concrete product with the apparatus of the invention. FIGS. 4A and 4B shows examples of reinforcement bars, and FIGS. 4C and 4D shows examples of the parts forming a lifting loop.

[0042] Since in the present invention the parts are embedded into the concrete product before the final compaction of the product is attained, the parts sections located inside the product to be cast can be formed to contain larger sections so that good shape-based attachment and anchoring of the part to the concrete can be obtained. Further, the compaction taking place after the embedding of the part allows also better attachment of the concrete mass to the part at whole of its embedded length.

[0043] The material of the parts is generally metal, such as steel, but other high tensile strength materials, such as basalt fiber materials, may be used.

[0044] The specific exemplifying embodiments of the invention shown in the figures and discussed above should not be construed as limiting. A person skilled in the art can amend and modify the embodiments in many evident ways within the scope of the attached claims. Thus the invention is not limited merely to these described embodiments.