Abstract: In the casting of a concrete element, such as a column support block, in which there is used a mould core designed to produce one or more recesses or grooves in the element, the mould core is provided with one or more apertures or slots, in each of which there is arranged a recess-forming mould part which can be moved in said aperture or slot by means of a ram. Prior to a casting operation, the moveable mould part is moved to an outwardly projecting active position and, subsequent to the cast element hardening, is withdrawn by means of the ram, thereby to enable the cast element and the mould core to be separated from one another. All of the moveable core parts on one side surface of the mould core can be arranged on a plate extending parallel to the corresponding side surface of the mould core and arranged to be acted upon by the ram.

Abstract: In a method of manufacturing consecutive pre-tensioned concrete elements, e.g. concrete sleepers, in a long mould bed, reinforcement ropes are tensioned and closure members are placed between different elements. Prior to casting closure members which are so formed that two or more cast elements are joined together via bridges or shoulders projecting outwardly fron the elements and surrounding the reinforcement ropes are placed in the mould bed at predetermined intervals. The string of cast elements is advanced to an element-separating station at one end of the bed where the elements are successively cut by means of a diamond saw or the like. The bridges between the elements are formed in a manner such that the reinforcement ropes are protected and a small, preferably the smallest possible section of concrete between the elements is severed when the elements are separated from the string of elements.

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 Hardening of the concrete is accelerated by heating, and the core is withdrawn from the formed post before the concrete has completely hardened.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.

Abstract: In a method of manufacturing a reinforcing unit in the form of a cage or basket for a concrete post, the reinforcing rods are placed on pivotable, concave support arms in a fixture so as to form two separate concave parts of the finished unit. Support rings are then secured along said parts perpendicularly to the axis of the finished unit. The parts are brought together, and the support rings of one part are joined to the reinforcing rods of a corresponding part. The said parts are preferably brought together by swinging the support arms upwards in a manner such that the axis of the cage falls in a vertical longitudinal medium plane through the fixture. The support arms are pivoted downwards, whereupon a helical reinforcing element is threaded onto the unit from one end thereof and joined thereto.In this method use is made of a plurality of fixture units each comprising a frame, and two concave support arms pivotally arranged around horizontal shafts.