SU68849A1 - Reinforced concrete formwork - Google Patents

Description

During the erection of concrete structures, it is known to use an onalubka consisting of prefabricated reinforced concrete slabs used later as a lining. Such plates are typically interconnected by bolts through holes in the flanges bordering each plate. Endless plates are also used that are flush with each other, without any interconnection.

The disadvantage of all known constructions of reinforced concrete formwork plates is their relatively small height and the consequent need to install the plates along the height of the structure in several rows, which entails a significant increase in the number of different forms of plates, especially when erecting structures with variable sizes of horizontal cross sections.

A new feature of the formwork is that the formwork elements are made in the form of planks with metal longitudinal ribs protruding from the inside, for example, in the form of a truss, and installed in the direction of the height of the structure.

FIG. 1 shows a side view of a bridge support; in fig. 2 - plan of support with installed formwork; in fig. 3 shows a section along AB in FIG. one; in fig. 4 - the facade of one of the plates (boards) installed on a flat face of the support; in fig. 5 is a section along AB in FIG. 4, FIG. 6 is a section along VG in FIG. four; FIG. 7 - the facade of one of the plates (boards) installed on rounded parts of the support surface; FIG. 8 is a section along AB in FIG. 7; FIG. 9 is a section along VG in FIG. 7; FIG. 10 - a device for mounting and securing plates in the working position; FIG. 11 is a section along AB in FIG. YU; FIG. 12 is a detail of the upper part of the frame of FIG. eleven; FIG. 13 is an AB section of FIG. 12; FIG. 14 is a detail of the node A in FIG. 10fig. 15 is a section along AB in FIG. 14; FIG. 16 is a section through VG in FIG. 14; FIG. 17 - a part of compaction between adjacent formwork plates.

The lateral faces of the support are flat; fore and aft parts have the shape of a truncated cone half. For the formwork of buildings such a 87

Yes, plates (boards) of two types I and P are required. Type I plates have parallel edges and are installed along flat faces of the support; Type II plates are installed on the rounded sections of the support and have edges located along the truncated cone forming.

The construction of type I plates mounted on flat flange faces is shown in FIG. 4, 5 and 6. The slab has the form of a flat and thin board 7 and is made of durable and frost-resistant material, for example, from concrete, melted basalt, etc. The height of the slab is desirable to be set equal to the full height of the support.

To give the slab the necessary strength and rigidity, one or several metal ribs are attached to it, which, when subsequently concreting the structure, are embedded in the concrete and fulfill the purpose of the reinforcement of the concrete layer adjacent to the formwork.

The drawing shows one of the possible solutions for fastening the ribs: the plate is reinforced with a rib having the shape of a triangular truss; the attachment is made by inserting one face of the truss into the slab during its manufacture.

The truss is formed by three parallel round iron rods 2, 3 and 4, which are connected in pairs by means of zigzag bent rods 5 and 6. Rods 2 and 3 together with the plate / form along with the bending component, the other one is erased. 4. The bar 5, located in the plane of the slab, prevents the latter from chipping. The rods 6, located on the other two edges, perceive the shear force. With the appropriate location of fasteners element can work in the position of the console.

Between adjacent plates there are gaps that compensate for the inevitable inaccuracies in the width of the plates. The gaps are sealed before starting to concreting with soft round rubber 7.

88

After the concrete has hardened, the rubber is removed and the seams between the slabs are embroidered.

The design of type II plates installed on the rounded areas of the support surfaces is shown in figures 7, 8 and 9. These plates have a convex outer side and non-parallel edges.

FIG. 10-16 shows a device that serves to fix the plates (boards) in the design position and is used many times when building supports having different lengths and widths.

The slabs (boards) reinforced with ribs 70 are mounted on the foundation surface S against the wooden frame 9 attached to the foundation and having an outline along the internal contour, exactly corresponding to the outline of the structure at the level of the foundation trim. The correct position of the plates is fixed when they are attached to the upper outer frame.

To be able to reuse the one shown in FIG. 10-16 of the device in the construction of supports having different lengths and widths, the upper frame is composed of several elements. Some of these elements are inventory, others are variables, manufactured for a given length and width of the support. Inventory items are elements 77 and 73, made of pipe sections and welded to racks 75 and 76. The variables are: tubular insert 72, the length of which is selected depending on the length of the straight part of the outline of the support, and arc 74, made of round or corner iron. The design of the interface of the above-mentioned frame elements is shown in FIG. 14, 15 and 16. Arcs 74 are welded with their ends to circular metal sheets that are attached to the flanges of pipes 73. The joint is reinforced by the setting of corner beads 37.

The formwork plates are supported on round iron rods 30 welded to pipes 77, 72, 73 and flush with the inner faces of racks 75 and 76.

The rods allow the pipes 77, 72 and 13 to be moved away from the edges of the racks and, thereby, strengthen the attachment of the pipes to the racks and to each other (the cutting height at the flanges is reduced).

FIG. 10, the letter D denotes the length of the direct part of the outline of the support.

The formwork plates are attached to the upper frame with hooks, which are put on the frame and passed into the gaps between adjacent plates (not shown in the drawings).

The tubular elements of the frame 77 are connected to the uprights 75 and 76 using corner braces 77 and 18.

To fix the position of the frame in the plan, the upper ends of the racks are connected in pairs by bolts 49. To the left, the 16 bolts are rigidly attached, using struts 20 and bolts 28, connecting the bolts to the right racks 15 are hinged, using bolts 29, which pass through the cheeks 25. The upper 27 and lower 26 guide corners are welded to the cheeks, the distance between the horizontal shelves of which is equal to the height of the crossbar 19. The cheeks are fixed on the crossbar with four bolts. The struts 20 consist of two halves, in the junction between which a different number of shims 24 can be installed.

The above construction of connecting beams with the posts allows them to be used in the construction of supports having different widths and different inclinations of the side faces. To do this, it is enough to move the cheeks 25 around the bolt 19, set them at the required distance B from the second pair of racks, and change the number and thickness of the gaskets 24 to give the racks a predetermined angle to the vertical a.

A beam 27 is attached to the girders 19 for a hoist, which is used in the installation of slabs and concrete.

Such a device makes it possible to fix the correct position of the formwork boards and to perceive the wind load acting on them. The lateral pressure of the concrete is perceived by transverse straps, which are installed between parallel frame members. If you wish to use the straps repeatedly (do not leave them in the concrete), concreting should be done in two steps: first, the lower part of the structure is concreted, not the income is up to the struts, and then, after the concrete has cured and the layers are removed, the upper part.

Removable straps can be made of rope loops 22 connected by a screw mechanism 23.

Subject invention

Reinforced concrete formwork, for example, bridge supports, remaining in the structure as a lining, characterized in that the formwork elements are made in the form of planks having metal longitudinal ribs protruding from the inside, for example, in the form of a truss, and installed in the height direction of the structure.

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