The construction of any monolithic objects, be it a residential building or an industrial building, is not complete without wall formwork. This structure is necessary for the construction of walls and ceilings.
Manufacturers offer many variations to solve problems of any complexity, one of the most popular is the formwork of the Gamma series.
Formwork material
An important characteristic is the material from which the wall formwork is made. The calculation of the required amount of concrete depends on this, as well as its weight, strength, cost, installation and decoration. Formwork is made from:
reinforced concrete;
Each of the materials has its own advantages and disadvantages. Metal formwork is widely used in industrial construction (withstands high casting speed). However, at the same time it is very heavy, its installation requires the use of special equipment.
The form of expanded polystyrene is light, serves as an additional insulating layer. However, the low strength of the material complicates the construction (for example, a concrete pump cannot be used for pouring).
Wood, chipboard and plywood are also easily deformed, but at the same time provide easy and quick installation. Plastic is sensitive to negative temperatures, but durable and sealed. The main area of use is private construction (if you need to make a shallow foundation or a light building with your own hands), because their installation does not require special skills.
Large developers prefer to work using removable structures, which also include Gamma formwork. Depending on the purpose, it can be used for the construction of:
round structures (columns, pillars);
overlaps.
The calculation of the required volume of concrete is carried out taking into account the type of formwork.
Advantages of removable structures
If we are not talking about one-time construction, prefabricated large-panel or panel formwork is the best option, thanks to the following advantages:
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Installation of removable formwork
The main components are a block and fastening elements (). Depending on the type of construction (panel board, large panel board), the block can be from 90 * 60 cm., And up to 330 * 120 cm. The calculation of the required size of the panels is based on the scale of construction. For the construction of a small house, or a conventional panel formwork with blocks of 1.5 * 1 m is the best option.
Panel formwork is easily assembled with your own hands, installation does not require the use of special equipment, and various components allow you to assemble a structure of any shape. This makes it indispensable for pouring foundations or erecting walls and ceilings of a one-two-story building.
The frame of the shield is made of a metal profile (high-carbon steel or aluminum alloy). Shield - plastic or plywood, in some cases finishing with reinforcing material is provided. Installation of additional stiffeners guarantees the strength of the structure.
A significant advantage of the non-removable form is its cost and easy installation. The construction of monolithic houses with this design allows you to minimize labor costs. Installation of other structures consists of the following stages:
- a corner block is being mounted and walls are being erected;
- installation of door and window openings is in progress;
- concreting is carried out (each stage of pouring is performed after the previous layer has solidified).
Features of large-panel formwork
The large-panel formwork Gamma has, in addition to the listed elements, the following components:
an inner corner to make a corner block;
hinged shields, with which you can form internal and external corners of any radius;
arcuate element, to obtain a rounded section of a wall or floor;
screeds that rigidly fix the shields to each other.
Also, to facilitate work at a height, the set can be supplied with a platform for workers, which can be easily attached to the block at the level of any floor. Components can be purchased as needed, the calculation of the required amount will be done by specialists.
Large-panel formwork is used in the construction of large-scale objects, therefore, special requirements are imposed on it. The block must be able to withstand the high casting speed and its rigidity must ensure the ideal geometry of the walls and foundations. This is achieved through the following design features:
solid-rolled profile shield;
a special lock that allows you to insert additional sheets between the boards, up to 10 cm thick (for strengthening the structure or additional heat and waterproofing);
fasteners simultaneously pull and fasten the shields together;
the block is covered with a special, protective coating (powder paint), such an external finish helps to prevent corrosion.
Today Gamma movable removable formwork is the most optimal solution in terms of price-quality ratio.
Wall formwork application (video)
The choice of formwork for various objects
They are mainly used in the construction of the foundation of small objects (cottage, garage) with their own hands. Trench installation and pouring are done manually. For heavy structures, the foundation and walls are reinforced with reinforcement. External and external finishing is possible immediately after the concrete has hardened.
Permanent panel formwork made of expanded polystyrene has become a popular solution for the construction of small private houses. The thermal insulation properties of expanded polystyrene can significantly save the cost of heating the room. In addition, the decoration of such a building (both inside and outside) is not particularly difficult. Most of the finishing materials (plasterboard, facing boards, lining, veneer) are easily attached to expanded polystyrene sheets.
A removable panel formwork can be installed to build a shallow strip foundation, in which case it acts as a basement. Wooden or - an optimal solution for the price, since a shallow foundation does not imply the use of complex structures. It is easy to assemble and disassemble it with your own hands, using the tools at hand.
Large-panel formwork (for example, Gamma 330) is used in the construction of multi-storey buildings, industrial facilities, etc. At the same time, due to its configuration, it is easily transformed into a form for floors, supporting elements. The accompanying documentation indicates possible assembly schemes and the calculation of the necessary elements.
Versatility. Components (special fasteners, swivel elements) allow you to create structures that are complex in shape.
Before proceeding with the construction of formwork for a strip foundation, let's take a look at how many types of formwork structures there are.
The quality of the entire construction largely depends on the quality of the work performed on the installation of the formwork and on the base of the house, that is, on the foundation.
Formwork types
The formwork design, depending on the type, is divided into two groups:
- Removable formwork;
- Formwork that has a non-removable structure.
In construction, the formation of a monolithic, concrete and reinforced concrete structure is indispensable. And it doesn't matter if it is a house, or a pre-built frame, which is called formwork.
In the case of self-construction, the formwork for the strip foundation is made with our own hands. The main thing is to choose the type of formwork and correctly complete all its step-by-step construction.
Let's take a closer look at each of them.
So, the formwork structure, as already mentioned, is removable, and not.
The most famous and widely used type of construction. Removable formwork, which means that after pouring the strip foundation, this type of formwork must be dismantled.
In addition, in this case, it is removed immediately after the pouring concrete has set.
Thanks to this type of formwork, it is possible to form a foundation with any shape. This applies not only to strip foundations, but also to staircases, monolithic walls, and so on.
A removable structure is made using:
- Cutting boards;
- Plywood sheets, which differs from plywood with the usual increased moisture resistance;
- Steel sheets, which can be made of any material, that is, both steel and aluminum.
But, for the construction of a strip foundation, it is better to use cut boards, moisture-resistant plywood and wooden beams. It is also possible to simplify the process of formwork construction by using a special metal frame for fastening grooved boards.
At the same time, remember that it is not worth installing the formwork using only plywood. It can only be used if the foundation is small.
Better to opt for beams and wooden boards.
It does not matter from what material the formwork structure is built. The main thing is to observe the basic installation rules during construction.
Fixed formwork is considered an advantageous type and easy to install, besides, the construction speed in this case is much higher than with a fixed structure.
For its construction, the material at hand is most often used. It can be chipboard, fiberboard, metal frame, or even metal or asbestos pipes with a diameter of 150 to 200 mm. Therefore, this is a huge plus.
Such formwork is easy to install and does not require large earthworks. No spacers or supports are required during erection.
Non-removable
Permanent formwork types
Metal
This type is considered the most expensive. It is made from steel sheets with a thickness of 1 to 2 mm.
The advantages of this type:
- good
- It easily takes the desired shape of the foundation
- A strip or monolithic foundation will perfectly fit the metal formwork
- The outer side is easy and simple to process
- high price.
Reinforced concrete
This view is considered a relative option.
Advantages:
- Depending on the thickness of the concrete slabs, the consumption of the concrete itself can be significantly reduced. At the same time, its strength will not decrease in any way.
- The slabs are very heavy
- If the slabs are not monolithic and the height of one will not be enough, you will have to make spacers
Expanded polystyrene
This option is considered the most practical. In this case, the formwork is assembled from separate blocks, which are fixed to each other.
Advantages:
- Installation is simple
- It is possible to give a certain shape
- Warming
- The price is not very low
- The complexity of the selection of some elements
Wooden
As a material, you can take sheets of plywood or a board.
Advantages:
- Good price
- Material availability
- Installation is simple
- No need to purchase additional equipment for installation
- Due to the different dimensions of the material, it may be necessary to use additional means to strengthen and connect the formwork
Materials at hand
What materials at hand can be used in the construction of formwork?
- Pipes
- Corrugated board
- Slate
- Any other suitable material that can provide the desired shape while preventing cement leakage
Advantages:
- Cheapness of construction
- Complexity of assembly
- Concrete leakage during pouring
- Possibly low carrying power
- Additional supports may be needed
How to make a permanent formwork for the foundation with your own hands?
Do-it-yourself fixed formwork for the foundation
It is being built in several stages.
First stage - earthworks
After calculating the required capacity of the future formwork, a trench is dug.
Tip: leave a margin of 1 to 2.5 cm between the ground and the future formwork. This method will simplify installation.
If you decide to use reinforcement, then you need to install it at this stage.
The second stage is the construction of formwork elements
At this stage, the formation of the reinforcing cage takes place, if it is used. In addition, a structure is being erected with the selected material.
After these stages, concrete is poured. In about 25 - 30 days, construction can begin. During this time, the concrete will set and harden and it will be possible to proceed to the next stages.
How to assemble the formwork for the strip foundation
- The frame of the structure is only rigid, with a solid fixation of all elements;
- The elements of the formwork should not have gaps, all the parts of the formwork are exactly matched to each other;
- The formwork must withstand the generated pressure of the concrete solution.
Material is being prepared. These should be cut boards, 20-45 mm thick. Width is not important. But the wider the board, the easier and faster it is to construct the formwork.
A shield is knocked down from the prepared board with a height in accordance with the height of the foundation.
The shields are fastened together with wooden beams using self-tapping screws, and only the screws are screwed in with caps from the inside. The slots are additionally lined with slats in accordance with the dimensions of the board.
The very same formwork construction instruction looks like this:
- Preparation of the workplace, that is, digging trenches, procurement of building materials and tools;
- Cut the boards to size according to the size of the foundation;
- Manufacturing of shields;
- Securing the formwork, securing the strength from the outside of the structure;
- Test of strength.
Correctly performed formwork construction work - complete absence of problems during the manufacture of the strip foundation.
When erecting walls using monolithic construction technology, several types of formwork can be used. In the construction of large civil and industrial facilities, removable panel formwork is relevant, allowing you to quickly erect long and high walls. In the private sector, a non-removable type of formwork systems is used, which makes it possible to fill an entire building along a finished contour. Each of the varieties has its own pros and cons, as well as device features.
Removable panel wall formwork
The first stage in the assembly of removable formwork is the drawing up of a detailed project, which should take into account all the typical and geometric features of the structure being erected. Also, before installing and fixing the molding complex, the corresponding calculations are made, which determine:
- optimal wall thickness, taking into account climatic features and bearing capacity of architectural elements and formwork;
- brand of concrete and reinforcing elements.
Installation diagrams of removable panel formwork for various wall options
After drawing up the technological plan, they proceed to the process of arranging the formwork system, which includes:
- connection of formwork panels with each other using locking mechanisms and ties;
- installation of a deck sheet made of waterproof plywood;
- fastening the formwork with struts;
- installation of reinforcing elements;
- connection of ready-made blocks (panels), standing in parallel using clamping screws.
Wall formwork panels are connected in successive segments using locks of various types, which provide reliable fixation and a sufficient level of strength. Wedge and universal locks can be used in straight segments. Pivots or special ties are used to fasten the corner shields. After the formation of a block of the required dimensions, it is necessary to fix it in a vertical position and create conditions for 100% stability.
Wall formwork panels are connected in successive segments using locks of various types
The deck can be installed in a horizontal or vertical position, depending on the dimensions of the formwork frame. Fixation of the contact surface to the frame ribs is carried out by means of special fastening devices, the type of which also depends on the type of formwork system.
The struts will help to fix the complex of formwork panels in a vertical position, as well as to carry out the adjustment. There are two types of these devices: two-level and single-level. They are distinguished by their bearing capacity and load distribution mechanism. A two-level strut is used for larger structures with a high load index.
Reinforcement of the casting mold is carried out in accordance with the technological requirements for the structure. Based on the functionality of the wall (load-bearing or not), the type of reinforcement (type, thickness, etc.) is selected. When placing a reinforcing element between the formwork panels, there must be sufficient space for the concrete to form the outer edges of the slab. To ensure a stationary position of the reinforcement inside the formwork, special clamps are used.
To ensure a stationary position of the reinforcement inside the formwork, special clamps are used
After placing the formwork segments in a vertical position (parallel) and laying the reinforcing elements, they are fastened with a tightening screw, which ensures reliable coupling between the parallel walls of the formwork. After completing this stage and carrying out all the necessary engineering and technical checks, the concrete mix can begin to be pumped.
Permanent wall formwork
Fixed formwork for the construction of monolithic structures can have various shapes. In addition to the main functions, the material used to create the molding space plays the role of insulation, therefore, the use of this type of formwork is advisable in low-rise private construction. As a rule, in this case, polystyrene foam blocks are used.
The device of this type of formwork for monolithic walls consists in forming a molding contour by connecting polymer blocks by means of profiles already installed on each of the elements. The wall thickness depends on the type of block used. Pouring the wall can be started after the blocks have been bonded, the form has been reinforced and all checks have been carried out.
Wall reinforcement in permanent formwork
The installation of slab formwork can differ in different parameters, which is characterized by the type of product and the peculiarity of the work. In this article, we will consider the types of formwork for floors, and also describe detailed instructions for installation.
Types of products for overlap
All work on the installation of floor formwork is intended for the construction of buildings or houses in a monolithic way. When carrying out work, it is important to adhere to the rules and recommendations in order to ensure the strength and stability of the structure. The formwork installation technology must be carried out by workers or specialists in this field.
Before proceeding with the installation of floor formwork, it is important to consider the parameters and types of this type of product. There are such types of structures:
- on wedge scaffolding;
- formwork on cup scaffolding;
- on volumetric bowls;
- formwork on telescopic racks.
For telescopic racks made of steel, formwork is used when the ceiling height is no more than 4.6 meters. When erecting a structure of greater height, it is important to use volumetric slab formwork. In this case, the installation is intended for monolithic floors made of reinforced concrete, with a height of 20 meters and a thickness of up to 70 cm. For this type of formwork, it is necessary to use vertical posts, inserts, jacks, crossbars and other connecting elements. All assembly and disassembly work is not complicated.
The peculiarities of installing telescopic slab formwork are to fix the tripod in the base, which supports the entire structure. At the same time, the installation technology is carried out using special shields. They are made of plywood which is waterproof. In fact, plywood panels are essential items for assembling formwork.
A different type of construction is carried out on wedge scaffolding, which are used for the installation of floors in a multi-storey building. They can be used for other purposes, however, instead of plywood, scaffolds are laid on them and ladders are fixed, which is necessary for lifting workers. Wedge scaffolds have a prototype design, which consists of horizontal and vertical racks. They can be connected at different angles, which will allow you to perform efficiently on difficult sites.
The technology for installing floor formwork on cup scaffolds consists in installing a structure in the form of a frame. This method differs from the previous one in that the variant of connecting the racks must be done by the cup method. This will allow 1 to 4 pieces to be placed on one level in 1 bowl.
Features of the assembly of formwork for beam floors
The technology for the installation of floor formwork involves the use of beams made of reinforced concrete. They carry out the main load of the building. Therefore, the formwork is important not only for the floors, but also for the beams themselves. You need to start work after the completion of the installation of the columns.
First of all, the beams are fixed in special grooves, which are located in the formwork structure of the columns. After that, you can start installing the telescopic racks, however, it is important to remember the permissible heights. All supporting elements are recommended to be installed on tripods, which are fastened with crossbars, which will increase the stability of the beam floor.
Next, proceed to the installation of the formwork walls, which are important to fasten together and the bottom, using special fasteners. An additional element of strengthening is the flooring of beams made of wood. It is also important to install telescopic slab formwork underneath them. The last stage of work is the installation of panels on the sides of the formwork and the laying of a reinforcing frame. In this case, it is necessary to additionally check the following aspects:
- the final procedure for adjusting the formwork;
- checking the level of floor beams and other elements;
- establish the presence of sags or deflections, which are important to eliminate.
Features of installing formwork without monolithic beams
The formwork installation scheme using this technology can be compared with the installation features for a beam floor. However, this method is simpler, since there is no need to install additional railings, they are intended for pouring monolithic beams. You should be aware that for the assembly of the formwork, it is important to adhere to the requirements and rules that determine the installation distance of the support posts.
- The installation step should be no more than 2 meters if the ceiling height is up to 230 mm.
- A step of 1.7 meters is used for floors with a thickness of 28 cm.
- If the overlap is about 320 mm, then it is advisable to put the racks every half a meter.
During installation work, it must be remembered that the distance between the racks described above has the maximum values. Therefore, it is recommended to slightly reduce the step between the supports. Plywood, plastic and other building materials can be used as shields for the construction of floor formwork. It is important to know that in order to obtain a good quality surface, it is important to use laminated products. If you plan to use plywood, it is important that it is moisture resistant.
Features of installing polystyrene foam formwork
This installation scheme has some nuances, which are important to remember when installing the formwork. The design scheme is designed for specific cavities, which are designed to form reinforced concrete load-bearing beams. This will reduce the amount of work. At the same time, in all the details of the formwork there are special niches through which you can lay various communications, such as sewerage, water supply, electricity.
An approximate scheme for creating a formwork for a monolithic floor made of expanded polystyrene does not present certain difficulties, so that 2 or 3 people can participate in the work process. The installation technology is advised to start with the installation of racks and load-bearing beams.
It is important to know that the direction of the beams should be perpendicular to the position of the panels and to the perforated metal profile, which will enhance the bearing capacity. If you need to carry out the necessary communications through the formwork, then you can cut an opening in the wall, while it is important to seal the joint area.
Features of dismantling work
The parameters for dismantling the formwork may depend on various factors, which are determined by some regulatory and design documents. In this case, the deadlines depend on some factors:
- the brands of concrete used;
- the time of the year when the installation work is carried out;
- thickness and parameters of the overlap.
As a rule, in summer it will be possible to remove the formwork after 3 or 4 days, but it is recommended to continue construction work only after 3 weeks. In winter, the drying time of concrete is extended, depending on damp and cold weather. The essence of dismantling the formwork is the simplest disassembly of parts. If the design has special falling heads, then the dismantling process is greatly simplified.
Also, the use of such parts will allow partially to carry out the work, but it is possible to simultaneously remove the formwork of the floors, the photos of which can be seen on this website. You can determine the time for removing the structure if you calculate the level of concrete strength, the indicator of which should be from 70 percent.
How to make slab formwork: step by step instructions
In a similar situation, we will consider the features of the construction of formwork for monolithic floors. They are often used in current construction. If in the process of work we use high-quality materials made according to the latest technologies, then this will reduce the weight of the structure, load parameters, which will reduce construction costs.
High-quality performance of the work ensures the correct installation of the formwork, because the pouring and formation of the foundation is not a difficult process. As a rule, builders use several options for using formwork, some of which offer to purchase a ready-made structure, and the latter prefer to do everything with their own hands.
It is important to know that the formwork for the floor slab is made by this method: the frame is assembled from vertical racks, which are fastened together with special beams-crossbars. They are nailed perpendicularly to the transverse beam on which the plywood flooring is laid. It must be laminated and moisture resistant, which forms the bottom of the formwork. To carry out the work, it is necessary to prepare the following materials:
- support posts, which are bars with a section of 120x120 mm up to 150x150 mm;
- crossbar and crossbar - has the form of an edged board, the cross-section of which is 160-180x50 millimeters;
- braces, which represent a board that has a thickness of 3 cm;
- flooring, moisture-resistant plywood is used, the thickness of which is 1.8 cm.
For such work, it is not necessary to purchase expensive materials made from coniferous trees, which is very uneconomical, therefore, several alternative options can be distinguished:
- use lumber that is intended for the rafter system;
- use previously used products that were previously used in construction;
- preference for materials that are made from low-grade tree species, such as soft-leaved ones.
To carry out the work, you need to make a calculation of the formwork of the floors, namely, to install the required number of supporting elements, which are the racks. So, when assembling the formwork, it is important to consider the post placement steps. All parameters and distances have been specified in this article.
Step-by-step instructions for installing the formwork:
1. Given the thickness of the floor, we recalculate the steps between the beams, thus forming the first row. To do this, drive a longitudinal bar into special grooves with nails into the upper ends of the support posts. The approximate half-groove depth should be the same as the ledger. This will provide the correct support load. Further, we fix the ends of the longitudinal bar to the wall.
2. In the same way it is necessary to assemble the second row for the formwork. The base for the structure must be solid and level. To do this, it is advised to put the board under the supports, the thickness of which should be about 5 cm.
3. Attach a cross bar perpendicular to the longitudinal bar with a set distance of 60 cm. Next, install the support posts, the verticality of which is checked using a plumb line.
4. Using the same technology, you need to install the rest of the rows in order to create a frame of the required parameters.
5. It is important to level the horizontal beams using the building level, and the height of the posts is easy to adjust.
6. It is important to fasten all racks together using braces. They can be attached with nails, while their position should be diagonal. At the same time, you need to ensure that the entire frame of the racks is strong and reliable enough for further work.
8. It is important to keep the ends of the floor from freezing. Thus, along the perimeter, you need to make masonry, for example, from aerated concrete blocks. For brick walls, it is necessary to lay out four rows of brickwork, the thickness of which is 12 cm. And the outer side is recommended to be insulated with foam.
10. We carry out the pouring of concrete solution. It is recommended to dismantle the formwork after 20 days.
The formwork installation scheme for different types of slabs represents the implementation of a large amount of work, the implementation of which will require huge costs. Of course, the formwork can be built with your own hands, or you can purchase a new structure. In this case, all costs will be the same.
Slab formwork: assembly instructions, Construction portal
Construction of houses Installation of floor formwork can differ in different parameters, which is characterized by the type of product and the peculiarity of the work. In this article we will look at
Any construction of buildings provides for the mandatory installation of floor slabs, which can be either purchased ready-made or manufactured directly at the construction site. Moreover, the latter option is very popular, since it is considered less expensive. To make monolithic slabs yourself, you need to create a special structure - floor formwork.
Device
A monolithic floor is one of the main elements of the structure, which increases the operational characteristics of the building and makes it durable. Its installation begins with the assembly of the formwork, which allows the concrete to maintain its shape and immobility until it hardens. Slab formwork is considered to be a complex building structure, which usually consists of such elements.
- Support nodes. These are wooden beams that look like telescopic racks. In order to evenly and correctly distribute the dynamic load on this element, the distance between them should be accurately calculated. With the help of such supports, formwork is assembled for pouring monolithic slabs with a height of no higher than 4 m. Often, additional or starting racks are used in the construction of structures. They are made of a metal profile and are fixed to each other with special fasteners (cup or wedge). Thanks to such supports, formwork up to 18 m high can be built.
The uprights, which are commonly used for formwork installation in high-rise buildings, consist of three elements: a fork, a vertical support and a tripod. The fork is the upper part and serves, as a rule, to fix the working surface. It is also often referred to as the "support fork". This element is produced from four tubes (square section), which are welded at the corners, and metal plates with a thickness of at least 5 mm. The tripod (skirt) is designed to stabilize the stand and allows it to be held securely horizontally. In addition, the tripod takes on part of the main load when pouring concrete.
According to the standards, in the construction of ordinary residential buildings for the installation of an auxiliary structure, it is allowed to use racks of the following sizes: 170-310 cm, 200-370 cm.If you plan to build a private house outside the city, then you can get by with supports of a typical size of 170-310 cm, they are placed with a step of 150 cm.
- Base. It is made of sheet material, which is most often used as plywood sheets, metal profiles and boards from boards. To increase the strength of the structure, it is recommended to use a material with high moisture resistance.
- Metal or wood beams. These elements are placed perpendicular to each other. For the construction of the formwork, you need to choose beams with increased rigidity, since the retention of the concrete mass and the strength of the formwork itself depend on this.
Slab formwork can be made of various types, it all depends on the type of support, the thickness of the concrete pouring and the height of the structure.
Advantages and disadvantages
Slab formwork is considered an indispensable building element. However, they have both advantages and disadvantages. Therefore, before building them, it is important to take into account all the characteristics. The main advantages of formwork include such moments.
- Providing high strength to monolithic slabs. Unlike conventional prefabricated structures, they do not have joint zones and seams.
- The ability to implement non-standard projects, since such formworks allow the manufacture of floors of various shapes.
- Elimination of displacement of floors in the transverse and longitudinal direction. Monolithic slabs acquire additional rigidity.
- Simple installation. Formwork can be created on our own without the use of special equipment, which significantly saves construction costs.
- Reusable. Reversible formwork is used to cast hundreds or more of monolithic slabs. It is financially beneficial.
... As for the shortcomings, there are not many of them.
- Compared with the use of ready-made slabs, the time is higher, since it is required to additionally erect and dismantle structures. In addition, the construction process is a little delayed, since you have to wait for the concrete filling to gain strength.
- The need for strict adherence to the entire technology of manufacturing and pouring concrete solution. This is difficult to do, because concrete is poured in huge quantities.
Views
Slab formwork, designed for concreting monolithic slabs, is of several types, each of which differs in assembly technology and technical characteristics. Most often, the following type of structures is used in construction.
Stationary (non-removable)
Its main feature is that it cannot be removed after the solution has solidified. Stationary formwork consists of sheets of thermal insulation and layers of waterproofing material, therefore, they provide the building with additional heat and protection from moisture. At the end of concreting, non-removable structures are transformed into one of the elements of the reinforced concrete structure. These structures have a number of advantages: they simplify installation work, reduce labor costs, and give the structure a decorative look, as they are made of modern materials.
Detachable
Unlike the previous type, these structures can be dismantled after complete solidification of the concrete. They are in greater demand than stationary ones because they are characterized by a low price and easy installation. Many builders rent removable formwork, as this allows you to reduce the cost of assembling the structure and quickly complete the concreting process.
Collapsible
This type of formwork is divided into several classes and differs in the level of complexity. So, for example, when building horizontal planes, a simple (frame) formwork is recommended, but if it is planned to erect buildings of complex shapes, then a volumetric (large-panel) structure is suitable. The assembly of such elements is carried out from moisture-resistant plywood, profiled sheet, polystyrene foam, polystyrene and expanded polystyrene.
In addition, sliding formwork is sometimes used for the construction of small and large modules. It is installed vertically. The type of construction is chosen in construction, depending on the complexity of the project.
Technical requirements
Since the slab formwork is responsible for the further strength of monolithic blocks, it must be erected in accordance with the established building codes, taking into account all technologies and rules. The following requirements apply to this design.
- High safety margin. Each constituent element of the structure must withstand not only the reinforcing cage, but also the weight of liquid and hardened concrete.
- Safety and reliability. During the reinforcement and pouring of the mortar, workers move along the base, so it must be rigid and exclude any vibration. Otherwise, monolithic slabs can get defects, which in the future can lead to emergency situations. Construction tables also help to exclude damage to the integrity of the structure, on which you can also move during construction work.
- Long service life. This primarily concerns the collapsible and removable type of formwork, which are used multiple times in construction. To create a monolithic floor, it is recommended to install formwork made of durable material that will withstand subsequent operation after dismantling.
- Resistance to stress. Since the concrete is poured superficially and with a depression, its mass creates increased dynamic loads on the formwork. In order for the structure to reliably withstand them, it is necessary to correctly select its material of manufacture in advance and prepare a plan for the foundation slab, which complements the formwork drawing and the slinging diagram.
- Have a fast installation. Today, there are many support parts and ready-made sections on the market that allow for quick assembly of structures.
- Disassembly possible. After the mortar has frozen, the formwork, consisting of several elements, can be dismantled for further use. This process should be quick and easy.
DIY installation
The installation of slab formwork is considered a responsible and complex process, so if you plan to assemble it yourself, you must have some experience and comply with all the conditions of technology. Many builders prefer to purchase ready-made monolithic slabs; for their installation, only jacks and workers are required. The only thing is that construction equipment is not always available for use and in hard-to-reach places it will not be able to work. Therefore, in such cases, it is best to make monolithic blocks with your own hands. To do this, you need to strengthen the formwork, after which the concrete is poured. In more detail, the construction process is as follows.
- At the first stage of work, accurate calculations should be made. For this, design is carried out and an estimate is drawn up. In the project, it is important to take into account the strength of the formwork so that it does not crack under the mass of concrete mortar. In addition, a slab placement scheme is made, taking into account the features of the configuration of the future building, the concrete grade and the type of reinforcement. So, for example, for the construction of an ordinary residential building, the width of the spans in which will not exceed 7 m, you will need to make a solid floor with a thickness of at least 20 cm.
- At the second stage, the purchase of all the necessary materials is done. These are the foundation for the formwork, supporting and fastening elements.
- The next step is to assemble the formwork itself. Its installation should be started after the walls have been erected, when their height has already been set. For horizontal casting, you can use two types of formwork: ready-made (purchased or rented, it only requires assembly) and non-removable. In the first case, it is recommended to choose a structure made of durable plastic or metal, it can be reused after completion of work. The complete set of such formwork usually includes sliding supports to keep the floor at a certain level. They are assembled very simply and quickly.
In the second case, you will have to assemble the formwork with your own hands from plywood and edged boards. It is recommended to take plywood with increased moisture resistance, and it is best to select edged boards of the same size, this will save you from adjusting them in height in the future. First of all, the foundation is being prepared for monolithic slabs. In the event that gaps appear between the elements during the assembly of the formwork, then a waterproofing material is additionally laid. You can also make a structure from corrugated board. It is much easier to work with it and this material eliminates the formation of gaps.
Great attention should be paid to the choice of plywood. It is advisable to purchase laminated or glued sheets with increased moisture resistance and a thickness of 18 to 21 mm. This material is made from several layers of wood veneer, each of which is laid across the fiber. Therefore, this type of plywood is durable. The installation of plywood sheets must be carried out in such a way that their joints fall on the crossbars, in addition, after assembling the formwork, not a single seam should be visible.
The installation process should begin with the installation of supports that will support the future monolithic block. Both sliding metal elements and homemade ones from logs are well suited as racks (they must have the same thickness and height). The supports must be placed in such a way that a distance of 1 m remains between them, while the distance between the near supports and the wall should not exceed 20 cm. Then, beams are attached to the supports, which are responsible for holding the structure. They are additionally equipped with horizontal formwork.
