Opulubus (from the word of the plub) is called an auxiliary structure made of metal, wood or other material, which gives monolithic structures from building mixtures of the type of concrete solutions certain parameters – shape and geometric dimensions, surface structure and spatial location. The formwork system is a prefabricated design that forms the forming elements and fasteners.
Factory formwork
By the degree of disassemble, the formwork is divided into two types:
Removable formwork, which is subject to dismantling after recruiting with a building mixture of prescribed strength, capable of maintaining a given position in space and configuration of the outlines of the hardened structure. Historians assure that even when erecting the pyramids, ancient Egyptian builders used a mobile wooden formwork;
Non -removable formwork that is not subject to dismantling and remaining in the construction structure. The use of non -removable formwork also deep historical roots – brick or stone blocks for formwork were used in the 3rd century BC. e. Ancient Roman builders.
Classification of formwork systems
The basic requirements for formwork are set out in the state standard 52085-2003 “Formwork. General technical conditions “. This standard applies to all types of formwork systems and unequivocally does not classify them only by the degree of disassembly, but introduces other technical indicators.
The design of the formwork system
The fundamental features of the differences are:
Type of concrete structures for which the system is assembled for filling:
Vertical and inclined-vertical monolithic constructions such as foundations, walls and columns, bridges, pipes and gradish;
Horizontal and inclined-chorisontal monolithic structures such as ceilings, domes and arches, bridge spans and overpass.
The design of the most formwork system:
Small -quality – collapsible or modular;
Large -quality – collapsible or modular;
Block, which includes detachable, inexhaustible and redesigned block forms of external and internal contours;
Non -removable, which is divided by the influence of the calculated section of the created structure;
There are also systems of sliding, voluminous and other types of formwork structures.
Turning through:
disposable, including non -removable formwork for the foundation or other elements of buildings;
inventory, that is, reusable use.
The materials from which the supporting elements are made:
Steel;
Aluminum;
Wood and plywood;
Plastic;
Combination of materials.
Applicability at various temperatures:
Insulated or unsuitable;
Heating;
Special.
The use of non -removable formwork
Construction technologies are rapidly developing. Even established technological processes are modernized, which have hundreds of years of application. The construction of houses from non -removable formwork is gaining popularity, when the formwork design after hardening of concrete is not dismantled inside it, but becomes part of a monolithic finished wall, foundation or other structural unit of structure.
If, when using removable formwork systems, it was necessary to collect a frame and install in advance pits or trenches in advance, so that then sweat on dismantling work, then the technologies of non -removable formwork suggest only the assembly of ready -made components of the elements. At the same time, special construction equipment is not required at all.
The elements of the formwork used, which are part of the erected structure, will perform the functions of heat – hydraulic – and sound insulation. Many craftsmen install non -removable formwork with their own hands using polystyrene blocks or other materials. Installation does not require special skills and complex tools, blocks are easily sawn and processed.
Materials for non -removable formwork
Foam polystyrene
This material has already become a classic building material for new technology due to its technical characteristics:
High thermal insulation properties;
Good mechanical strength;
Good breathability;
High mechanical strength;
Water resistance;
Frost resistance.
Usually used plates with a thickness of 50 mm brand PSB-C 25-35. They are interconnected by jumper. And higher and lower blocks are applied by means of locks of a special shape according to the type of game-designer of Lego, a small pressure on the edges is enough so that the locks are tightly connected.
Foam polystyrene
Slip -cement panels and blocks
Structural formula of the material – crushed wood in the form of a chip plus cement, often this composition is also called wood -sided and arbolite. The formwork is assembled similarly to a traditional collapsible design of shields and boards using formwork panels and special screeds. If blocks are used, then blocks are placed in rows by type of seamless masonry.
Among the brush -cement slabs, non -removable formwork of Velox (Velox) is popular, which exceeds polystyrene panels in a number of indicators:
When using Velox formwork systems, even heavy concrete, having a large fractions filler, can be poured into the formwork, while the polystyrene foam “works” with light foam concrete;
Velox exceeds polystyrene foam in fire safety indicators, since the wood is subjected to special chemobotot, which makes the material resistant to decay, high humidity and burning. Polistyle foam gained fairly depressing statistics regarding its fire safety, especially due to the release of caustic toxic gases during fire and heating in the premises.
This is important! There is liquid glass in the bikes of cycling, which, with all its advantages relative to chemical resistance, prevents the normal “breathing” of buildings through the walls erected using this formwork. Therefore, it is necessary to immediately provide a ventilation system indoors of these buildings.
Glomagnesite formwork
Glomagnesite formwork
When using a mixture of magnesite and wood chips, a glass -deck sheet is obtained, which is widely used to build a house from non -removable formwork due to its high biofirestability, fire safety and frost resistance. Used as the enclosing structures of the walls, which then must be finished on both sides – both from the internal and facade.
This is important! The use of floods in non -removable formwork requires the observance of high homogeneity of concrete mixture, since the heterogeneous mixture will not ensure the subsequent required strength of the structure.