Columns are used in architecture: they support beams and floor slabs, and are 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, the construction of which uses formwork. If you plan to do such work yourself, you should understand the main types, as well as the features of the formwork installation.
Varieties of formwork
Column formwork can be classified according to the material of manufacture and method of application. According to the latter feature, non-removable, one-time and reusable formworks are distinguished. As for the material of manufacture, they 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 precise geometry, so it can be used to formquality surface of the monolith. Plastic formwork for columns 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 bars and sheets of plywood for this. You can make wooden formwork for the column yourself, but it is suitable only for rectangular products. The disadvantage is the complexity of the assembly to obtain a monolith with the correct geometry. As for the cardboard formwork, it is disposable. With its help, you can create cylindrical columns, and thick cardboard should be used, which is coated with special impregnations.
Formwork device
Formwork for a column is built according to certain rules. Like a wall, the future structure will have a small thickness, which is especially true when compared with height. This feature should be taken into account when calculating the loads. The pressure at the top will be less than at the bottom. There will be a big difference between the height and width, which negatively affects the stability of the formwork. In order to prevent collapse, additional reinforcement with props should be made.
Formwork should be made strong so that it can bear the weight of the concrete pour. Curvature is unacceptable, because the column in this case will turn out to be fragile. The installed elements for pouring must be strictly vertical. If this rule is not observed, then deformation forces will arise,which will destroy the architectural element.
Installation features
If you will install formwork for the column, then you can use plywood panels or wooden boards for work. In this case, the material can be disposable. This method allows you to achieve the formation of a square or rectangular element.
First, prepare a drawing with dimensions. Boards are assembled from boards, and their side in contact with concrete must be planed and sanded. Formwork installation provides for fixing stiffeners to the boards, which consist of wooden bars. The connection of individual shields is carried out using self-tapping screws and nails.
Next, you can start making the reinforcing cage. For this, the rods are connected in the shape of a rectangle, and for this you can use a knitting wire or a welding method. Wooden parts are exposed around the frame, which will form a monolithic formwork. In the lower part of the structure, the fastening must be especially reliable, because here the column will undergo a high load.
In order to make the described structure easier to dismantle, its inside should be covered with plastic wrap or linoleum. Formwork can be installed not only with plywood and boards, but also with extruded polystyrene foam or polystyrene foam. Such formwork is usually made fixed, in its center there is a plastic pipe, which is poured with concrete. Before filling the form with a solution,perform reinforcement and install props from different sides.
Assembly of cardboard formwork
When it is planned to erect a round column, special purpose cardboard is used. Among its advantages should be highlighted:
- lightweight;
- possibility of giving complex shapes;
- low cost;
- ease of installation;
- good thermal insulation qualities.
The last 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 the usual one. However, under such conditions, it is important to follow some rules:
- Fine-mesh reinforced steel mesh should be rolled up and its edges should be wired together.
- A roll is formed from cardboard and placed inside the mesh so that the material can spread out and lie on the mesh.
- The formwork is set in place and reinforced with props.
- To get a cardboard sheet of impressive size, overlap the material with adhesive tape.
Girder formwork
Formwork for pouring columns can also be beam-transom. Such forms are also used for the construction of walls. And the named type of formwork is available for self-assembly - no special machinery and equipment is required. For work, you should choose a flat area where it would be convenient to carry out assemblymanipulation.
Work methodology
- The crossbars should be placed on the deck at the specified distance.
- The wooden beam is installed perpendicular to the crossbars. Fastening is carried out with ties.
- Shields of thick plywood are fixed to the beams with self-tapping screws.
- Formwork boards from above and below are reinforced with beams. This will prevent deformation under the influence of the mass of concrete.
- Shields are connected by couplers, for which holes must be provided along the edges. In order for the ties to attract the shields in the corners as reliably as possible, wedge-shaped inserts will be required.
Beam-transom formwork boards can be reused, as well as metal and plastic elements. Only cardboard formwork is disposable.
Installation and arrangement of metal formwork
Metal formwork for columns is fastened panels of the required size. The elements are connected using mounting brackets. As a result, it is possible to obtain L-shaped blocks, which are completed in a single system. In the working position, they are interconnected by spring clips, which ensure their quick detachment when stripping.
Formwork for monolithic columns provides fastening with clamps that perceive the horizontal pressure of the solution and protect the shields from deformation. Separate parts of the clamps are hinged, which allowsquickly install and remove them. Before starting the installation of the pouring system on a concrete base, marks 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 ribs of the shields.
The position of the lower box is fixed with limiters made of rebar scraps, which are welded to the frame and outlets. The alignment of the formwork is carried out using wedge inserts. The second and subsequent tiers must be assembled from a mobile scaffold. Once the formwork has been fully assembled, it should be leveled vertically and secured with braces. The gaps between the base and the lower shields are boarded up.
Conclusion
With formwork, you can create columns of any shape and height. These structures 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.
