RU2388881C1 - Retained folding formwork for construction of cast-in-situ walls - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: retained folding formwork for construction of cast-in-situ walls includes parallel panels and hinged ties, vertical posts with panel and tie attachment devices located on external side of vertical post throughout their height. Panels of formwork are meshed, hinged ties are attached to vertical posts so that they can be turned in attachment devices, each one is made in the form of a zigzag so that sections inclined in plan view to surfaces of panels and sections in bend area, which are parallel to flat external wall of vertical post and contact it, are formed; at that, two hinged ties adjacent as to height are located in opposite phase relative to each other and fixed on posts in a staggered order. Hinged ties are fixed at one and the same height of opposite posts and located in one and the same plane.

EFFECT: improving stiffening characteristics of formwork system at the concreting stage and increasing the strength of sections of the built construction.

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Description

The invention relates to the field of construction and can be used in the construction of monolithic walls made of concrete and other similar materials, partitions, beams, frames, arches, arches, internal walls, in the construction of monolithic columns of any shape and cross section using fixed formwork during their construction, reconstruction and overhaul of facilities for various purposes, to strengthen the brickwork of buildings, as well as in the construction of utilities, shore and soil and hydraulic structures.

A known design of fixed formwork, which includes parallel panels and rigid fasteners - articulated joints, placed obliquely to the surfaces of the panels, while the formwork is equipped with vertical struts with means for attaching panels and articulated ties located on the outer side of the vertical struts along their height. The formwork panels are mesh. Swivel ties connecting vertical racks and simultaneously performing the functions of a swivel are connected to vertical racks with the possibility of rotation in the means for attachment, providing the ability to move the panels, and each is made in the form of a rod, curved in the form of a zigzag with the formation of sections located in plan obliquely to the surfaces of the panels, and areas in the zone of bending of the rod parallel to the flat outer wall of the vertical rack and in contact with it (see RU 2248433. Fixed formwork, method b its assembly and the method of erecting monolithic walls and structures in fixed formwork, MPK7 E04G 11/02, publ. March 20, 2005). Two articulated joints adjacent in height are in opposite phase relative to each other and are fixed to the racks in a checkerboard pattern, i.e. one articulated connection in the zone of its inflection is connected to one rack, and the adjacent articulated connection in the zone of its inflection is connected to the column installed opposite the first rack, and adjacent connections are installed at different heights. The advantages of the design described above are 1) the reinforcement of the concrete formwork poured inside without additional reinforcing elements, and 2) the folding formwork design, which allows it to be carried out under production conditions with high quality performance and transported to the place of use when folded due to the possibility of moving one panels relative to the other in parallel, forming a flat folding structure during transportation. The specified design is taken as the closest analogue.

The disadvantages of this design are the increased deformability of the formwork system in the direction “from the wall plane” at the stage of acceptance of the concrete mixture and a narrow range of values for the degree of reinforcement of the cross sections, limiting the scope of the formwork, depending on the values of the operating forces perceived by the constructed element.

The objective of the invention is to increase the rigidity characteristics of the formwork system at the concreting stage and to increase the strength of the sections of the structure being constructed.

The problem is solved by the design of non-removable folding formwork containing parallel panels and hinged joints, arranged obliquely to the surfaces of the panels, vertical racks with means for attaching panels and ties, located on the outer side of the vertical racks along their height, the formwork panels are mesh, hinged ties connecting vertical racks and simultaneously performing the functions of a swivel, are connected to vertical racks with the possibility of rotation in the means for attachment, providing the ability to move the panels, and each is made in the form of a rod, curved in the form of a zigzag with the formation of sections located in plan obliquely to the surfaces of the panels, and sections in the bend of the rod parallel to the flat outer wall of the vertical rack and in contact with it, and adjacent in height two hinged connections are located in antiphase relative to each other and are mounted on racks in a checkerboard pattern, i.e. one articulated connection in the zone of its inflection is connected to one rack, and the adjacent articulated connection in the zone of its inflection is connected to the column installed opposite the first rack. The difference between the proposed solution and the known one is the installation of two ties and their fastening on opposite racks at the same height. Thus, two hinged connections are arranged in pairs in the same plane opposite to each other and are mounted on staggered racks. This design of fixed formwork, having two hinge joints at the same height, located opposite in the same plane, and not in different planes in height, increases the percentage of reinforcement of the vertical sections of the erected wall, reduces the stresses in the racks that occur when pouring the formwork with concrete, by about two times, increases the rigidity of the formwork system at the stage of concreting by reducing the step of attaching ties to the racks by half; this allows you to increase the height and, as a result, the volume of concrete poured at a time. Bending forces in racks against hydrostatic pressure of the concrete mixture are up to 4 times smaller.

Under the action of bending forces on the finished wall structure in the plane of reinforcement, the tensile forces, poorly perceived by the concrete, are opposed by tensile forces of rod ties oriented at different angles to the wall surface. This compensates for the external impact to a greater extent than if one bond were located in one plane or if these bonds were established in planes of different heights. This increases the strength of the wall in bending after a set of concrete strength approximately two times at the same height of the wall.

The drawing shows the horizontal plane of the cross section of the proposed formwork design.

The formwork contains on one side a row of racks 1 and on the opposite side of the formwork a row of racks 2, made, for example, in the form of channels, on which two nets 3 are fixed along their height, one on racks 1, the other on racks 2 mounted on the outside of the racks . The formwork contains articulated connections 4 and 5, curved in the form of a sinusoid or zigzag, which are located in the same plane and are installed in antiphase relative to each other. To do this, at the same height of the racks 1 and 2 on one side to the even racks 1 of one row, a swivel connection 4 is fixed, which is fixed on the other side to the racks 2 of the second row on each odd rack. In antiphase, the articulated link 5 at the same height as the link 4 is fixed on each odd post 1 of the first row and on each even post 2 of the second row. And the mesh 3, and the hinge connections 4 and 5 are mounted on the posts 1 and 2 from the outside. Means for securing nets and articulated connections (not shown) can be made in the form of loops located on the outside of the racks. The nets 3 are fixed on the racks rigidly, and the loops for ties, covering them along the perimeter of their cross-section, allow the latter to rotate relative to the horizontal axis passing through the attachment point of the connection 4 (5) to the rack 1 or 2. The nets 3 can be made of steel and equipped stiffeners (not shown). The hinge connections 4, 5 can be made of rigid rods curved in the form of a trapezoidal meander, or of a wire curved in the form of a sinusoid. Such articulated joints 4 and 5, lying in the same plane in pairs, can be placed at different heights of the posts 1, 2, reinforcing the reinforcing effect for the wall.

The device operates as follows. The formwork is manufactured in an industrial environment, which ensures high quality, is formed by turning the joints 4, 5 in a hinge, while the panels parallel to each other, moving parallel to each other, form a planar small-sized structure in the plane of the panels, which is loaded onto the vehicle and folded delivered to the construction site. At the place of construction of the walls due to the articulation of the connections 4, 5, they are turned around, and the panels are moved apart by a width equal to the distance between the places of inflection of the articulated connections. Such an extended formwork is installed in its intended place and poured with concrete. Concrete fills the entire space between the panels, including racks 1 and 2, and the mounting points of the panels and articulated joints to the racks. Concrete pressure creates spacer forces on the panel. The spacer forces create tensile forces in the articulated joints 4, 5, the decomposition of which gives a reaction that counteracts the pressure, and compressive force in the longitudinal direction of the wall, perceived by the side mesh elements 3.

Since there are two articulated joints in the same horizontal plane, the distribution of the reinforcement elements is symmetrical in the vertical sections of the wall and positively affects the technological process of receiving the concrete mixture and the perception of external loads and effects by the finished structure.

All of the above is confirmed by experimental studies of samples - fragments of monolithic walls, performed by the authors. For testing, reinforced concrete samples were prepared using steel one-piece formwork 1.0 × 1.0 m in size, 16, 30, and 50 cm thick. The tests were carried out on an IPS-200 hydraulic press. The load was applied in steps of 10% of the calculated breaking load until the samples were completely destroyed. The strength and deformation characteristics of monolithic reinforced concrete walls erected using the proposed formwork were subject to a comprehensive analysis and evaluation.

Claims (1)

Fixed folding formwork for erecting monolithic walls, containing parallel panels and hinge ties, vertical racks with means for attaching panels and ties located on the outside of the vertical racks in height, the formwork panels are mesh, hinged joints are rotatable in the means for attachment, each is made in the form of a zigzag with the formation of sections located in plan obliquely to the surfaces of the panels, and sections in the bend zone a, parallel to the flat outer wall of the vertical rack and in contact with it, moreover, two height-articulate joints adjacent in height are in opposite phase and mounted on racks in a checkerboard pattern, characterized in that the articulations are fixed at the same height of the opposite racks and are located in one the plane.