FAQ

Monolithic structures – concrete and reinforced-concrete structures, which are concreted directly at site.

Storey – dividing of building vertically. May include one or several floors.

Concreting tact – part of monolithic construction (building), which is concreted in one cycle, and for which formwork is set simultaneously.

Grillage – construction of upper part of pile foundation, which is concrete or reinforced-concrete panel / beam, connecting piles into one strength system and passing load on the piles.

Reproping of formwork – propping of formwork on bearing structures other structures before dissmantling.

Dissmantling – dismantling of formwork after concreting and concrete fixation.

Alignment – checking and slight moving of the set formwork constructions to provide their project location with defined accuracy.

Rigging  - temporary joint of the mounted, transported or lifted constructions with lifting hook (crane bracket).

Bearing capacity – calculated capacity of formwork and its elements to loads, including all safety factors.

Specific gravity – weight of formwork set (including accessories, braces, scaffolding etc.) to the unit of concreted surface area.

Hardness – characteristic of formwork, which depends on material and moment of inertia of the formwork section.

Adhesion to concrete – characterizes degree of formwork sticking to concrete.

Universality – ability to apply the same formwork set for different monolithic constructions.

Level of unification – saturation of formwork system with unified elements, which are used the same at different elements combination.

The cost of man-hours (time of crane usage) for formwork assembling and Labor costs for assembling (dismantling).

Turnover – quantity of concreting cycles from the start of new formwork usage untill the moment when it becomes unfitness, it is based on experience, statistics or by calculation method.

Forming element – contacts directly with concrete mixture and is used to reach the designed shape of the building; is needed to provide high quality of concrete surface.

Supporting element – supports formwork construction and accepts mounting loads.

Bearing elements – accepts all loads during construction, needed for strength and stability of all structure. Mounting element – device, designed for mounting and dismantling of formwork structure.

Joining element  – is used to join separate formwork elements; accepts loads during mounting and partially – during concreting.

Reference element  – is used for bearing formwork elements set.

Technological element – element used at work.

Purpose

Vertical formwork is used for vertical and inclined vertical monolithic buildings concreting (walls, columns, foundations, elevator shafts etc).

Horizontal formwork is applied for horizontal, inclined horizontal and spherical monolithic constructions, including: slabs, domes, bridges, bridge spans etc.

 

Peculiarities of construction

Small-panel frame formwork consists of small formwork panels, having weight up to 50 kg; is assembled by hands; it is used mainly at small objects.

Large formwork panels, with mass more than 50 kg, present Large-panels frame formwork. It is assembled with help of lifting crane.

Modular frame formwork consists of small and large formwork panels with fixed sizes, multiples of a particular module; all together these panels make the modular range, which allows solving any architecture tasks.

The listed formwork systems considered as demountable formwork – its separate forming, supporting, joining elements create different types of formwork structures.

There is also Block formwork, which represent separate space blocks to form closed inner / external contour of monolithic structures (buildings, columns etc).

To concrete walls and slabs simultaneously formwork sections are used, which form U-shaped and L-shaped structures in working position. This is the principle of work of Tunnel formwork.

Sliding formwork is used for bridges, tunnels construction and represents itself formwork construction, which moves constantly on vertical / horizontal surface, during concreting, with help of jacks or other mechanisms for moving.

Vertical-climbing formwork – is a system, which works according to principle of removing of panels from concreting surface by lifting with following support on building structure. In certain cases after concreting formwork becomes integral part of constructed building – non-removable formwork, and also can provide additional hydro isolation, decoration etc.

 

Materials, which are used at formwork manufacturing

The most strength, reliable and durable formwork is the one in which bearing and forming elements are made of steel (galvanized or with powder coating). Optimal variant for panels manufacturing is usage of special fine-grained steel with alloying additives, which fluidity and strength limits exceed the ordinary steel in several times. Special coating protects steel from corrosion and provides fast cleaning of formwork during exploitation.

Less heavy, but less strength variant also is formwork, which bearing and forming elements are made of aluminum. Such formwork loose primary shape and gets profile jams. This formwork could not be repaired without special equipment.

For small, single projects, when there is no necessity to have highly bearing capacity or exact panels, formwork with plastic and wooden frames is sometimes used.

There is also combined formwork – which bearing and forming elements are made of combination of different materials.

Turnover

Depending on durability and purpose, formwork can be for one usage (not removable or designed for unique structure) and inventory (modular) – for long-term using at different objects.

First formwork was used in ancient Rome. It was made of available items, most often of wooden beams. Instead of concrete was used mixture of mortar and fine sand. Such formwork was used even to build stone buildings.

At the 70s years of last century applying of concrete plates began. They were ordered at plants situated far from construction site. it was uncomfortable and expensive. Elements were installed not monolithically, but with welding. That is why often appeared problems with guy-sutures at the process of exploitation.

Specialists decided: all concrete elements are worth to produce directly on construction site.

At start wooden beams were used as formwork, but they were not reliable and were replaced by steel formworks (aluminum, steel) and plastic.

But soon it became clear, that during construction (especially for high buildings) the main role was playing by reliability and durability of formwork. Aluminum, plastic and more – wood not always respond to these demands. That is why the most often workers prefer frame formwork made of highly qualified, fine-grained steel.

Formwork – is temporary construction, which is used as form for concreting mixture and fittings for raising constructions of concrete and reinforced concrete (apartment complexes, industrial buildings etc.) and is assembled directly at the place of their construction.

The basic quality characteristics of formwork system are its strength, ease of use and durability.