CZ2004380A3 - Concrete beam subjected to bending and process for producing thereof - Google Patents

Abstract

The present invention relates to a floor concrete beam (1) comprising at least one metal element (2) subjected to prestress in bend, being disposed inside the beam and being completely embedded in concrete. The metal element, being bent by means of an external device consisting of an auxiliary metal element (2'), spacers (3) and a clamping device (4), is completely embedded in concrete after being placed into a mold. After concrete setting, said external device is removed.

Description

Bending stressed concrete beam and method of its production

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a concrete beam useful for bent elements of building structures.

BACKGROUND OF THE INVENTION

Reinforced concrete beams are used for bent elements of building structures. Their disadvantage is the deflection, which increases over time by the creep of concrete.

The object of the invention is a concrete beam with elimination of deflection under operational load. SUMMARY OF THE INVENTION

The requirement to eliminate deflection from operational load is solved by a concrete beam with at least one built-in flexurally prestressed bent metal element. The interaction of the concrete and the metal element eliminates the deflection of the beam from the load, as the element tends to return to a straight shape.

Advantageously, the metal element may be an I-shaped profile. The metal element may be deflected before concreting outside the beam, or spreading with the hardened concrete of the beam by means of anchor bolts and washers and subsequent concreting.

In the first case, the manufacturing process consists in placing the metal element bent by means of an external device into a mold or formwork and, after concreting and hardening the concrete, the external device is removed.

In the second case, the beam is made in two phases. After partial concreting and hardening of the lower part of the beam in the middle part of which the at least one anchor bolt is fixed, the metal element is placed with its ends on the washers located on the lower part of the beam and by bending the nuts on the anchor bolts.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in greater detail in the drawings, wherein FIG. 1 is a schematic representation of an embodiment of a bending of a metal element outside the beam, and FIG.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

In the example, the bending-stressed concrete beam 1 with the bent metal element 2 is bent.

The deflection of the metal element 2 was carried out outside the beam 1 by means of an external device composed of an auxiliary metal element 2j, a spacer 3 and a stripping device 4 as shown in FIG. 1. After deflection, the metal element 2 was inserted into the mold 5 and concreted. After the concrete hardened, the external equipment was removed.

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Example 2

In the example, the bending-stressed concrete beam I of Example 1 is bent, where the bending of the metal element 2 was performed by expansion so that the metal element 2 was placed in the mold 5 with its ends on the washers 6 . By tightening the nuts on the anchor bolts 7 passing through the metal element 2, this was bent and the beam L was subsequently concreted.

The bending-stressed concrete beam according to the invention is intended especially for building structures.

Claims (4)

1. A bending-stressed concrete beam, characterized in that it comprises at least one bending-bent metal element (2). Beam according to claim 1, characterized in that the metal element (2) is formed by an I-shaped profile. Method of manufacturing a beam according to claims 1 and 2, characterized in that the metal element (2) is bent by means of an external device, then inserted into a mold and after its concrete is concreted and the concrete is hardened, the external device is removed. Method of manufacturing a beam according to claim 1 and 2, characterized in that the lower part (1 ') of the beam (1) with at least one anchor bolt (7) is concreted and after the concrete has hardened the metal element (2) is placed on the supports (6). placed on the lower part (1 ') of the beam (1) and tightening the nuts on the anchor bolts (7) the metal element (2) is bent and then the beam (1) is concreted.