SU1386712A2 - Ferroconcrete girder - Google Patents

Abstract

The invention relates to the field of construction. The purpose of the invention is to increase reliability. The beam contains the USSR region 982. The region will hold the prestressed polygonal reinforcement 1, the envelope element 2 and the fixing element B. The envelope element 2 has the shape of a groove and is made of a square or rhombic outline of the billet of steel sheet bent along One of the diagonals, and with holes placed along the edges of the other diagonal, Element 2 is fixed with a nut 7 on a threaded rod 6, which is installed in the slots of the fixing element. Element 8 is a two-legged rod, made of two parts, connected by means of transverse struts 9. 6 Il. BuffA 10 s (/: s

Description

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The invention relates to the construction, in particular to reinforced concrete beams of building structures, and is an improvement of the invention according to the author. No. 1127960i

The purpose of the invention is to increase reliability.

Figure 1 shows a reinforced concrete beam with locking elements installed in it; in fig. 2 - construction of the interface unit of the envelope and fixing elements with polygonal reinforcement, general view; in fig. 3 is a view A in FIG. figure 4 - preparation of the envelope element; in fig. 5 - fastening of the envelope element to the polygonal reinforcement; in fig. 6 - slot on the wall of the plug.

: The beam contains a pre-expanded polygonal reinforcement 1, a dying element 2, made from a square or rhombic outline of the workpiece 3 from a steel sheet with a bend along diagonal 4 and with holes 5, a threaded rod 6, I nut 7, an inclined element 8 s The armature 9 and the fork 10 at the end and the pro- rection of 11 on its side walls 12. In addition, the angle c / - is indicated between the direction of the slot 11 and the end of the fork 10.

In the manufacture of the beam, the workpiece 3 is bent diagonally 4 in the form of a lobber, which, by unwinding, is fixed at 1 in places of bends of the polygonal reinforcement 1 by tightening the nuts 7 on the threaded rod 6, threaded into the hole 5. The square or rhombic shape of the workpiece 3 is dependent on from the required tearing strength of the area adjacent to the hole 5 from the outside. The length of the threaded rod 6 is greater than the distance between the walls of the inclined element 8. The upper and lower polygonal reinforcement bars are equipped with such grooves. One of these valves (for example, the bottom) is fixed on the stops of the stand or the end of the force form in the design position, while the other (for example, p-jep, top) is positioned with a slack. Thereafter, inclined elements 8 are inserted between the upper and lower polygonal reinforcement. Each inclined element 8 is a two-legged rod consisting of, for example, two corners.

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connected by spacers 9. The distance between the branches of the inclined element 8 corresponds to the distance between the rifled surfaces of the nuts 7. The spacers 9 are arranged along the length of the inclined element 8 so that forks 10 are formed at the ends of it. The shelves of the corner branches located along the beam, provided with slots 11 at an angle of 70-80 to the end of the plug 10. The oblique elements 8 are fitted with slots. 1 1 to the ends of the threaded rods 6. Thereafter, the polygonal reinforcement having slack is fixed in the grippers of the jacks and tensioned to a controlled voltage.

The location of the slot -11 at an angle of 70-80 ° is due to the fact that this angle must be different from the right angle so as to prevent the inclined element from slipping when it is deformed under the influence of tensioned reinforcement. Excessive reduction of this angle requires increasing the stroke of the jack. When tensioning a reinforcement, the ends of the grooves, located on diagonal 4 and having the shortest flexural rigidity along the length, deform, providing a smooth transition from one polygonal reinforcement section to another. Thus, the formation of the envelope elements 2 is completed, and the entire system of polygonal reinforcement 1 and inclined elements 8 is transformed into a flat suspended tension system, ready for concreting. The preservation of the plane of this system is ensured by the support of the struts 9 in the side walls of the formwork.

The proposed device ensures the reliability of the beam in the manufacturing process, contributes to the performance of the beam.

Claims (1)

Invention Formula Reinforced concrete beam according to the author, No. 1127960, characterized in that, in order to increase reliability, the beam is provided with elements enveloping and fixing the reinforcement, and the reinforcement bar is made in the form of a square sheet or rhombic billet, bent along one of the diagonals and with a hole under the threaded rod with a tensioning nut, by means of which the element enveloping the reinforcement is fixed in the reinforcement fixing element made of two corners, jointed between each other by cross-bracing and at the ends in the side walls there are non-through cuts under the threaded rod. FIG. 2 C) and 2.1 ig.TS b