A variety of formwork types can be used in the construction of buildings and structures. Similar structures serve for the construction of monolithic walls, foundations, etc. The most common type of formwork is small-panel formwork. It differs from the large one primarily in size. The main advantage of this design is ease of use.
Scope of application
Small-panel formwork can be used in the construction of a variety of objects. In addition to walls and foundations, similar structures are used, for example, during construction:
- columns;
- overlap;
- curbs, concrete sidewalks;
- benches, barbecues, etc.
Benefits of using
Small-panel formwork can be used for both ground and underground construction. Its undoubted advantages include:
- lightweight shields;
- ease of installation;
- no needuse of special equipment during assembly;
- possibility to perform any assembly combinations.
Small-panel formwork device: main elements
Most often, collapsible structures of this type are used in construction. Similar formworks consist of:
- corner and linear shields;
- compound trusses and skirmishes;
- supporting poles (in formwork for building floors);
- connecting and fastening elements.
Technical and economic indicators of an adjustable design can have, for example, the following:
- turnover - 100 times;
- reduced mass - 65 kg/m2;
- installation labor intensity is average - 0.6 man-hours per 1 m2.
These are the characteristics of one of the formworks, developed back in Soviet times by Gosstroy specialists. In our time, more modern designs of this type can be used. For example, small-panel steel formwork "Kvarta" has the following characteristics:
- turnover for steel frame - 100 cycles;
- for deck - 60 cycles;
- average shield weight - 26 kg/m2.
Modern industrial formwork can be made from wood, steel or other materials. To receiveclean and smooth surface of the object under construction in such structures, an additional element is used - the deck. It is made either from moisture-resistant plywood, or from tin. The deck is usually attached to the main formwork elements with self-tapping screws.
Views by assembly method
Most often during construction, thus, collapsible panel structures are used. But sometimes modular formwork of this type is also used to pour monolithic structures. Such structures are able to withstand the pressure of a concrete mix of 40 kN/m2. Their main feature is that they consist of elements of a fixed size. Modular structures are usually made from laminated plywood with a thickness of more than 18 mm. The advantage of this type of formwork is, among other things, that when individual elements wear out, they can be replaced with new ones. With the help of such systems, surfaces of any configuration are easily formed. Most often, modular formwork is used in the construction of private houses and public buildings for various purposes.
The advantage of collapsible formwork is considered primarily that they can be installed in both planes. Moreover, such structures are assembled and disassembled very quickly. If necessary, with the help of formwork of this variety, even curved shapes can be poured. For example, it is these structures that are used in the construction of round concrete porches.
Types by turnover
On this basis, all small-panel formwork is classified into inventory and single use. In the first casethe design can be used repeatedly for the construction of mostly the same type of structures. Single-use formworks are required for pouring unique concrete objects.
Disadvantages of small-panel structures
These formworks have many advantages. But they also have some drawbacks. First of all, the disadvantages of such structures include the complexity of the assembly. Also, the appearance of finished structures erected using small-panel formwork may not be too neat. After all, the places of rearrangement of shields in height in any case on the surface of the object will be noticeable.
How the modular design is assembled
The assembly of this type of formwork begins with a corner element. Next, adjacent blocks are attached to the latter. In this case, connecting elements with special springs are used. The "walls" of such formwork are assembled using tie bolts. The supporting frame is formed from two panels installed opposite each other. The latter are connected using special locks. At the same time, the end and upper parts of the shields are fastened by means of spacer bars. For fixing in this case, locks are also used.
Installation of small-panel formwork adjustable industrial
The installation of this type of construction is also carried out in several stages:
- an auxiliary structure is mounted (using corners and shields);
- adjacent panels are installed;
- adjacent panels are fixed withspring hooks;
- the assembled box is placed in the design position and straightened.
The concrete mixture is usually poured into the formwork using a vibrator.
Standard dimensional requirements for industrial structures
Many manufacturers produce small-panel formwork. But in their manufacture, in any case, GOST standards must be observed. Thus, the area of one formwork panel should not, for example, exceed 3 m2. The minimum weight indicator is 50 kg. It is these dimensions that allow you to mount the structure without the use of special equipment.
Dimensions of small-panel industrial formwork of the same brand can be different. For example, for the popular Framax design, the height indicator can be 135, 270 or 330 cm. There are five standard sizes of shields for the designs of this brand in width - 30, 45, 60, 90 and 135 cm.
Homemade options
Very often small-panel formwork is used for the foundation and monolithic walls and in private construction. Industrial structures of this type are used most often by small, medium and large construction organizations. When building houses, private individuals usually still use much cheaper home-made formwork. You can use any improvised materials for such a design. Making it with your own hands is quite simple.
Homemade formwork, in turn, is also divided into two main varieties - conventional and adjustable. The advantage of the lattertype of designs is material saving.
It consists of self-made collapsible small-panel formwork, usually of two panels and elements designed for their fastening. In the process of work, it is moved along the perimeter of the object under construction. The disadvantage of this type of construction is, first of all, that the building elements poured with it are less durable and reliable.
Ordinary stationary self-made collapsible formwork is installed around the perimeter of the entire facility under construction. Its advantage is reliability and a more accurate appearance of the finished structure. The disadvantage of such auxiliary equipment is the difficulty in assembly / disassembly and the need to use a large amount of materials.
Strength elements of self-made formwork
Such formworks can be mounted from a variety of materials. Shields are most often assembled from boards. Fasten them with bars. Tin can also be used to make shields. This material is often used, for example, to fill curved objects.
As spacers for self-made formwork, bars or reinforcing bars of the length corresponding to the width of the object being erected can be used. Shields are most often fastened with steel wire. Sometimes bolted connections are also used. From the outside, the structure is additionally reinforced with struts made of beams.
Dimensions of homemade formwork
Shield widthsuch structures depends on the height of the object under construction. According to the regulations, the difference between these two indicators should not exceed 5 cm. Small-panel wall formwork is most often assembled from two to three boards 150 mm wide. In this case, the construction turns out to be light enough so that it can be quickly moved around the perimeter of the object under construction on its own.
The maximum allowable length of self-made formwork panels used for pouring walls and foundations is 3 meters. Boards for assembling such a design must have a thickness of at least 20 mm. Bars for their fastening, spacers and struts are usually chosen with a section of 40x40 mm. The minimum thickness of tin for the assembly of such formwork is 1-2 mm.
