The column is used in architecture: it supports beams and floor slabs, and is also used in the design of entrances to cottages. Columns allow you to create rooms with an impressive area without partitions. The most durable among them are monolithic structures, in the construction of which formwork is used. If you plan to do such work yourself, then you need to deal with the main types, as well as the features of the installation of formwork.
Varieties of formwork
Column formwork can be classified by material of manufacture and method of use. By the last sign, non-removable, single and reusable formwork is distinguished. As for the material of manufacture, then as it are:
- metal;
- plastic;
- wood;
- cardboard.
Among the advantages of the first variety is the ease of installation and dismantling of the structure. Steel formwork has an exact geometry, so with its help you can form a high-quality surface of the monolith. Column formwork is most commonly used for round structures. It can be made from a water pipe, the diameter of which will be suitable.
And with the help of boards, wooden structures are assembled - they use for this bar and sheets of plywood. You can make wooden formwork for the column yourself, and it suits exclusively for rectangular products. The disadvantage is the complexity of the assembly to obtain a monolith with the correct geometry. As for cardboard formwork, it is disposable. With its help, you can create columns of a cylindrical shape, and use should be dense cardboard, which is covered with special impregnations.
Formwork device
The formwork for the column is built according to certain rules. Like the wall, the future structure will have a small thickness, which is especially true when compared with the height. This feature should be considered when calculating loads. The pressure at the top will be less than at the base. There will be a big difference between height and width, which negatively affects the stability of the formwork. In order to exclude collapse, additional reinforcement with props should be made.
The formwork should be made strong so that it can undergo the weight of the concrete pouring. Curvature is unacceptable, because the column in this case will be fragile. Installed elements for filling should be strictly vertical. If this rule is not observed, then deformation forces will arise that will destroy the architectural element.
Installation Features
If you will be installing the formwork for the column, then for work you can use plywood panels or wooden boards. In this case, the material may be disposable. This method allows to achieve the formation of an element of square or rectangular shape.
First you need to prepare a drawing indicating the dimensions. Shields are assembled from the boards, and their side in contact with concrete should be planed and sanded. The installation of the formwork provides for fastening to the boards of stiffeners, which consist of wooden blocks. The connection of individual shields is carried out using self-tapping screws and nails.
Next, you can begin to manufacture a reinforcing cage. To do this, the rods are connected in the shape of a rectangle, and you can use a knitting wire or a welding method for this. Around the frame are exposed wooden parts, which will form a monolithic formwork. In the lower part of the structure, the fastening should be especially reliable, because here the column will undergo a high load.
In order to make the described construction easier to dismantle, its inside should be covered with a plastic film or linoleum. Formwork can be installed not only with plywood and boards, but also with extruded polystyrene foam or polystyrene. Such formwork is usually made non-removable, in its center is a plastic pipe, which is poured with concrete. Before filling the form with a solution, reinforcement should be performed and the supports installed on different sides.
Assembly of cardboard formwork
When it is planned to build a round column, special cardboard is used. Among its advantages should be highlighted:
- a light weight;
- the ability to give complex shapes;
- low cost;
- ease of installation;
- good heat-insulating qualities.
The latter factor is especially important in the cold season. When it is planned to install formwork for round columns, and there is no special cardboard at hand, you can use ordinary. However, under such conditions it is important to observe some rules:
- The fine-mesh reinforced steel mesh should be rolled up, and its edges should be fastened with wire.
- A roll is formed from cardboard and placed inside the grid so that the material can straighten and lie on the grid.
- The formwork is put in place and strengthened by props.
- To obtain a cardboard sheet of impressive dimensions, you should connect the material with an overlap with adhesive tape.
Girder formwork
Formwork for pouring columns can also be beam-crossbar. Such forms are also used for walling. And the named type of formwork is available for self-assembly - no special equipment and machinery are required. For work, you should choose a flat area where it would be convenient to carry out assembly manipulations.
Methodology
- At the specified distance, the crossbars should be placed on the floor.
- A wooden beam is installed perpendicular to the crossbars. Fastening is carried out by couplers.
- Shields of thick plywood are fixed to the beams with self-tapping screws.
- Boards for formwork above and below are strengthened by bars. This will prevent deformation under the influence of the mass of concrete.
- Shields are connected by couplers, for which holes should be provided at the edges. In order for the screeds to attract the shields in the corners as reliably as possible, wedge-shaped inserts will be required.
Boards for the formwork of the beam-crossbar system can be used repeatedly, as well as metal and plastic elements. Disposable is only cardboard formwork.
Installation and arrangement of metal formwork
The metal formwork for the columns is fastened boards of the required size. The elements are connected using mounting angles. As a result, it is possible to obtain blocks of the L-shaped form, which are completed in a single system. In the working position, they are interconnected by spring brackets, providing them with a quick connector when stripping.
The formwork for monolithic columns provides for fastening with clamps that absorb the horizontal pressure of the solution and protect the panels from deformation. The individual parts of the clamps are pivotally connected, which allows you to quickly install and remove them. Prior to installation of the casting system on a concrete base, risks are applied with paint. This allows you to fix the position of the axes in two coordinates. The same risks should be applied to the end edges of the shields.
The position of the lower duct is fastened with limiters from the scraps of reinforcement, which are welded to the frame and outlets. The alignment of the formwork is carried out using wedge inserts. The second and subsequent tiers should be collected from mobile scaffolds. Once the formwork has been fully assembled, it should be aligned vertically and secured with braces. The gaps between the base and the lower shields are boarded up.
Conclusion
Using formwork, you can create columns of any shape and height. These designs can have arbitrary parameters. To date, two types of work are known, the first of which involves the installation of formwork for universal columns. The second technology involves the formation of formwork with a fixed section.
Previously, columns were used only as a decorative element, today they serve as supporting elements for various buildings.