SU920159A1 - Ferroconcrete under-rafter truss - Google Patents

Description

I

The invention relates to construction and can be applied to various industrial, agricultural and public buildings.

Closest to the proposed one is a reinforced concrete subrafter truss, including upper and lower casts, prestressed reinforcement and closely spaced racks foamy with themselves in nodes tl.

Known bezoskosnye trunnion farms do not work well on the effects of asymmetrical load, which occurs during overhead cranes, one-way technological and snow load, especially in differences in building heights and in buildings with large spans. In the elements of such subrafter trusses, significant bending moments occur, which leads to a large waste of materials and makes the subrafter farms economically inexpedient.

The purpose of the invention is the elimination of bending moments in the elements of the subrafter ferles, an increase in the span and the possibility of supporting more than two roof trusses.

This goal is achieved by the fact that in reinforced concrete trusses, including upper and lower sa, prestressed reinforcement and paired close racks connected to the nodes themselves, the truss in the middle part between the outer racks is made with additional paired close racks and braces, connect the top and bottom nodes

IS with paired parallel racks, and the pre-stressed reinforcement is passed through these braces and fixed in the nodes of the upper platform.

In addition, for the purpose of uniform

Claims (3)

20 tensioning the brace tension reinforcement, providing for anchoring of the bracing reinforcement at the nodes of the lower belt, the latter are equipped with roller bearings. In order to ensure reliable zakavkerivaniya {) ASTAnuyu fittings owls in the upper along the crosscut truss in the nodes of the upper cabinet are made with reinforcing cages in the form of a spatial lattice holder covering the pre-stressed reinforcement in the zone anchored. FIG. 1 shows a reinforced concrete sub-truss; in fig. 2 — node I in FIG. one; on fng. 3 - section AAA fig. 2; in fig. 4 - node y in FIG. one; in fig. 5 is a section BB in FIG. 4. Reinforced concrete subrafter trusses include upper along with 1, lower along with 2 with tensioned reinforcement, paired parallel vertical uprights 3, race-4, tensioned reinforcement 5 diagonals roller support 6 and spatial reinforcement frame - holder 7. Diagonal 4 in the middle subrack trusses are symmetrically located with respect to the symmetry axis of the truss and are made to descend to the node. Rebar 5 at node 1 pro moves continuously. It bends in the direction of the braces 4 by means of the roller on the symmetry axis of the truss 6. The second support roller assembly 6 prednapr conjugated struts 4 is transmitted from the load mounted symmetrically between the uprights 3 trusses. Paired vertical pillars 3, located in the middle of the truss, absorb the load from the floor slabs, their weight, top floor 1, and racks in the node and this is transferred to the braces 4. At the node t, reinforcing spatial is installed in the anchoring zone of the tensioned reinforcement 5 frame (yoke) 7 to ensure the reliability of anchoring the tensioned armature of diagonals. Such a constructive solution to a subrafter truss allows you to create edani, performed in precast concrete with a large grid of columns, to expand the area of rational use of precast concrete and increase its efficiency. Compared with the well-known iron-concrete subrafter, flat-cutting trusses, the economy of concrete, steel cost is approximately 15%. Claim 1. The reinforced concrete sub-ram of erma, including upper and lower o sa, pre-stressed reinforcement and paired close racks connected to themselves in nodes, characterized in that, in order to eliminate bending moments in the elements of subrafter truss, increase the span and the possibilities of supporting more than two truss trusses, the truss in the middle part between the extreme uprights are made with additional paired close-up posts and diagonals connecting the nodes of the upper and lower truss with paired parallel racks, and the prestressed reinforcement is passed through these braces and fixed in the nodes of the upper rail. 2. The farm according to claim 1, with the fact that, for the purpose of equal-. measuring tension of the brace reinforcement and securing of an anchor of the brace reinforcement in the nodes of the lower platform, the latter are equipped with roller axles. 3. The farm according to claim 1, characterized in that, in order to ensure reliable anchoring of the stretched armature of the diagonals in the upper half of the cross, the subrafter truss in the nodes of the upper belt and 1 is filled with reinforcing cages in the form of a spatial lattice holder covering the zone of anchoring prestressed reinforcement. Sources of information taken into account during the examination 1. Liberman A.D. Bezraskosnye subrafter crooked 18 m span of high-strength concrete. - Concrete and reinforced concrete, 1970, No. 2, p. nineteen.