US 4,178,338 AGranted

Method of casting thin-walled, hollow concrete posts

AssigneeA-Betong AB

InventorsPer-Erik Bondpers, Gote Liljegren

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Abstract

In a method of casting in a horizontal mould a hollow, reinforced tapering concrete post having a thin wall and particularly a length exceeding 10 to 15 m, there is placed in the mould a tapering reinforcing cage or basket in which a core, e.g. a steel core, is inserted to form a substantially annular mould chamber. Said mould chamber is closed with the exception of an upper filling slot. A readily pourable concrete mass is charged to the mould from above through said filling slot. The mould is then vibrated without being rotated such that concrete fills the annular mould chamber. Hardening of the concrete is accelerated by heating, and the core is withdrawn from the formed post before the concrete has completely hardened. The finished post is then removed from the mould. The concrete mixture used shall have a settling or slump measurement of between 1 and 5 cm prior to charging a flow-promoting agent, and a settling or slump measurement of between 12 and 14 cm subsequent to charging said flow-promoting agent. The concrete mixture has a stone size of at the most 8 mm. The core is preferably withdrawn 1.5 to 4 hours after completion of the casting operation. The invention also concerns a mould for casting concrete posts of the above mentioned kind.

Claims4

Dependent claims

A method of casting a hollow, reinforced, tapering concrete post having a thin wall and a length exceeding 10 m in a hoirzontal mould, a tapering reinforcing cage being disposed in the mould and a core of steel or the like being disposed within the reinforcing cage and centered within the mould by a plurality of support posts extending radially inwardly from the sides of the mould to thereby define an annular mould chamber having an elongated filling slot running along the upper side thereof, comprising the steps of:

(a) charging a readily pourable concrete mass into the annular mould chamber through the filling slot, said concrete mass comprising 16 to 20% by weight of cement, 4 to 8% by weight of water, a sufficient amount of flow-promoting agent to provide a slump measurement of between 12 and 14 cm, and an aggregate having a maximum size of 8 mm including 40 to 50% of said aggregate being gravel having a maximum size of 4 mm,
(b) vibrating the mould for 10 to 25 minutes without rotating it to settle the concrete mass and evenly fill the annular mould chamber,
(c) simultaneously and thereafter heating the concrete mass to accelerate its hardening,
(d) allowing the mould to remain stationary for 15 to 30 minutes,
(e) revibrating the mould for 2 to 3 minutes,
(f) withdrawing the core from the post 1.5 to 4 hours after the charging of the concrete mass and before it has completely hardened, and
(g) removing the finished post from the mould.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/875,724Filed 7 Feb 1978
Priority: SE 77013427 Feb 1977
Granted: 11 Dec 1979
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

B28B 1/08
Producing shaped prefabricated articles from the material: by vibrating or jolting
B28B 7/0044
Moulds characterised by the way in which the sidewalls of the mould and the moulded article move with respect to each other during demoulding: the…
B28B 21/76
Methods or machines specially adapted for the production of tubular articles: moulds
B28B 23/0056
Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material;…