SU909076A1 - Inflated form for constructing monolithic ferroconcrete structures - Google Patents

Description

FIG. Figure 1 shows the pneumatic formwork, general view; in fig. 2 - the same cross section.

The main elements of the formwork are the shell 1 with vertical end walls of elastic material 2, the desired position of which, after inflating the formwork, is provided by a system of flexible horizontal 3 and inclined links 4. Along the edges of the formwork to hold the concrete mix, flanges 5 are arranged, connected to each other links 6. The formwork before the concreting is laid longitudinal rod reinforcement. The transverse arch of the arch consists of spirals, the ends of which are hinged on the foundation 7, and flexible rods laid in spirals towards each other. One end of each rod is fixed on the foundation 7. In addition, the formwork includes a soft covering coating 8 consisting of two panels. The lower edge of each panel is attached to the foundation 7 by the presser bar 9, and the upper edge of the panel is attached by an elastic element 10 to the foundation of the roof 7 on the opposite side. The size of the panels is chosen so that when the formwork is raised, the edges overlap by at least 50 cm. The introduction of elastic elements into the top panel allows you to adjust the degree of concrete reduction and, moreover, allows you to use conventional rubberized fabrics and films instead of special ones. - astral materials. The characteristics of the resilient elements may vary depending on the stiffness and thickness of the concrete mix, which makes the formwork more versatile.

The operation of the pneumatic form is as follows.

The flexible casing of the formwork 1 is flattened and fixed along the contour on the foundation 7. The end walls 2 should be below the working casing.

After installing the longitudinal and transverse reinforcement and fixing it on the foundation 7, the concrete mix is laid evenly over the entire area of the base. The size of the coarse aggregate in the concrete mix must not exceed the distance between the turns of the extended spiral reinforcement. From above, the concrete is covered with a cloth 8, the end edges of which are fastened to the upper edge of each flange 5. The bent edges of the flanges 5 are joined above the cloth 8 by ties 6. When air is forced through pipe 11 under the shell 1, the formwork together with the concrete rises to the design position. After vibrating the concrete, the pressure under the shell is maintained at

level throughout its coverage. When the concrete reaches sufficient strength, the pressure in shell I decreases and it is removed from under the concrete arch.

The proposed pneumatic formwork has been tested when concreting a model of a reinforced concrete arch with a span of 1 m and a length of 0.8 m. The tests show the reliability of all the elements of the formwork. The resulting arch has a regular cylindrical shape.

Claims (2)

1.Pneumatic formwork for the construction of monolithic reinforced concrete structures, including a flexible inflatable shell and an upper flexible retractable coating, characterized in that, in order to reduce labor costs and reduce the cost of building structures, the ends of the shell they are interconnected by internal flexible horizontal and inclined links distributed over the area and have upwardly protruding sides with bends directed towards the middle of the building's arch and stretched over the covering coating by flexible links. 2. Formwork according to claim 1, characterized in that the upper flexible covering layer is made with adjustable elastic tension elements. Sources of information taken into account in the examination 1. USSR author's certificate number 397625, cl. E 04 G P / 04, 1971. 2. USSR author's certificate number 335354, cl. E 04 G 11/04, 1972.