There are many methods of construction of residential and industrial buildings. And one of the most inexpensive technologies that allow you to build reliable and durable structures is frame. The basis of buildings constructed in this way is a solid frame. Various materials can be used to assemble such load-bearing structures. For example, buildings on a reinforced concrete frame are often erected.
When the technology can be used
Buildings of absolutely any purpose can be erected on reinforced concrete frames. This technology is great for the construction of both residential buildings and industrial workshops. Most often, multi-storey buildings are erected on reinforced concrete frames, of course. According to the regulations, this technique can be used for the construction of houses up to 25 floors high. Also, this technology is just perfect for the construction of large workshops.
In some cases, the construction technique on reinforced concrete frames can also be used for the construction of one - two-story buildings. Most often on such skeletonsbuild, of course, low-rise production workshops and warehouses. But sometimes owners of suburban areas also use this technology in the construction of small houses or summer cottages. Such structures are obtained not only very comfortable for living, but also durable. At the same time, houses of this design look very solid and presentable.
Varieties
Only three main types of reinforced concrete frames can be used in construction:
- national teams;
- monolithic;
- precast-monolithic.
The first type of skeletons is assembled from ready-made heavy reinforced concrete beams, columns and ties, manufactured at the enterprise. Monolithic frames of this type are poured directly on the site of the construction of buildings. Formworks are pre-assembled under the structural elements of this type of skeletons.
Prefabricated reinforced concrete frames, in turn, according to the installation method can be:
- frame;
- liaison;
- combined.
Advantages and disadvantages
The main advantage of building buildings on reinforced concrete frames, as well as on any other, is the freedom of planning. The spans in such structures can be both narrow and very wide.
Of course, the undoubted advantage of buildings on the reinforced concrete frame can be considered their cheapness. Such houses weigh less than brick, conventional panel and block houses. Therefore, they do not need to build too powerful expensive foundations.
Also, the advantages of this technology includeOpportunity:
- building very durable buildings;
- furnishing large areas.
In comparison with metal and wooden frames, reinforced concrete frames are characterized by increased strength. Also, the advantage of such load-bearing structures is, of course, the fact that they do not belong to the category of fire hazardous.
Some disadvantage of prefabricated reinforced concrete frames is the need to use expensive special equipment for mounting individual elements. The disadvantages of monolithic structures of this type include the lengthening of construction time. Concrete, unfortunately, matures for a long time - about a month. That is, the floors of buildings when using this frame assembly technology have to be erected intermittently. Builders need to wait until the supports are strong enough to support the weight of the heavy floors.
Reinforced concrete frame elements: columns
Finished reinforced concrete products intended for the construction of such buildings are usually made at factories from concrete grades from 200 to 400. To facilitate transportation, mounting loops are mounted in them at the manufacturing stage (or holes are drilled in their thickness). Depending on the size and number of storeys of structures, columns, beams, ties and crossbars of different sections and strengths are used during construction.
For example, when erecting reinforced concrete frames of industrial buildings, the floors of which will subsequently be subjected to serious loads during operation, columns 1.020 are used. Suchstructural elements are capable of withstanding loads up to 500 tons.
When constructing buildings, two types of reinforced concrete columns can be used:
- regular;
- used for workshops with overhead cranes.
Columns of the last variety consist of two parts: under-crane and over-crane. By location in the building, both of these types of reinforced concrete products are classified into:
- extreme wall;
- medium, mounted at the joints of spans.
The height of the precast concrete frame columns can be one, two or many floors. In form, such elements are:
- console;
- consoleless;
- T-shaped;
- L-shaped.
Reinforced concrete columns with a square, round, annular or rectangular section can be used in construction.
Horizontal elements
Reinforced concrete beams used in the construction of prefabricated reinforced concrete frames of buildings are classified into foundation and interfloor. Elements of the first variety usually have the shape of an I-beam. Their height can be 400 or 600 mm, and the width at the top is 300-400 mm. Depending on the length, the foundation beams can be basic and shortened. The latter type of element is often used, for example, near expansion joints.
Interfloor beams of reinforced concrete frames of houses in the section can be:
- T-shaped;
- rectangular;
- Z-shaped.
They can have a length of either a span or several,and one step between the columns.
Connections
Such elements of reinforced concrete building frames can be made of cement mortar using reinforcement or steel. They are necessary in order to ensure the spatial rigidity of the building. Connections can be established both horizontally and vertically. In some cases, they can also be mounted diagonally.
Foundations
Frame buildings are erected on prefabricated bases-blocks, which are a "glass" with a slab. Preparation for the foundations of such houses on dry soils is made of crushed stone, and on wet soils - from concrete grade 500.
During construction, the upper plane of this type of bases is placed 150 mm below the level of the finished floor. This installation method allows you to subsequently backfill the pit before installing the columns.
Under the outer walls, the foundation beams are laid in such a way that they go beyond the plane of the columns. Under the internal enclosing structures they are placed along the axial lines between the vertical supports. At the final stage, the foundation beams are waterproofed with two layers of rolled material.
Methods of mounting the prefabricated frame
The most reliable technology for the construction of buildings of this variety is frame. The reinforced concrete frame assembled using this technology is a rigid durable structure. Columns and beams are connected in such frames by welding metal reinforcement.
In the frame-braced frames of the reinforced concrete frameaccept only vertical loads. Horizontal in such structures fall on the floors. The latter, in turn, transfer the load to the flights of stairs. Also in this case, transverse and end walls are involved.
In articulated frames, the loads are distributed in the same way as in frame-bonded ones. The only thing is that the fastenings between the elements in this case are not used rigid, but articulated.
Beamless frames
Such structures are assembled in the form of a grid of 6x6, 9x6 or 9x9 m. The most popular version of the frames is the first one. The main elements of such cast iron skeletons are:
- columns with capitals;
- span plates;
- window slabs.
The buildings are erected on such frames much less frequently than on beams. This technology is mainly used only in the construction of industrial buildings with increased requirements for cleanliness. For example, workshops of dairies and bakeries, as well as refrigerated warehouses, are often built using this technology.
Frames of this variety are erected using a very simple technology. Interfloor slabs in this case are simply laid on the capitals of the columns and additionally fixed.
Prefabricated-monolithic frames: construction
Buildings are also built quite often on such skeletons. Connections in such structures, as in prefabricated frame ones, are provided rigid. Columns in the frames of this variety are used ready-made factory ones. The ceilings are poureddirectly on site in the formwork. This construction technology is most often used in the construction of low-rise buildings. Its main advantage is the reduction of time and cost of construction.
Technology for erecting a monolithic frame
Under such frames can be used as slab foundations, as well as strip or column foundations with a grillage. In this case, not only interfloor ceilings are poured into the formwork, but also columns. Using this technology, in most cases, not too large one- or two-story residential buildings are being built.
Includes a technique for building houses on a monolithic reinforced concrete frame, usually the following steps:
- building the foundation according to the standard method;
- filling columns;
- pouring floor slabs.
Elements in monolithic reinforced concrete frames of one-story buildings are rigidly interconnected. No hinge connections are used in such structures. The connection of columns with ceilings and the foundation in this case is carried out by means of reinforcement, followed by embedding with cement mortar.
Columns in such buildings are usually poured in formwork having a square or rectangular section. This makes it more convenient in the subsequent erection of walls. Under the ceilings, the formwork in such houses is mounted on special telescopic factory racks located with a small step from each other. Also in this case, supports made of logs of a sufficiently large section can be used.
Reinforcing cage in reinforced concrete structuresthe skeletons are made of thick steel bars. When assembling it, both welding and ordinary knitting wire can be used.
Interior and exterior walls
Foamed blocks are used in most cases as a material for enclosing structures of houses on prefabricated or monolithic reinforced concrete frames. The use of such material has a number of undoubted advantages. Foam blocks do not weigh too much. They are usually quite large in size, which allows laying as soon as possible.
Also, foamed blocks are not particularly expensive, which can also be attributed to their pluses. In the premises of buildings with such walls, a very pleasant microclimate is usually created. It is possible to lay out walls between the columns of a reinforced concrete frame both from large blocks in one layer, and from small ones - in several.
Walls are built from such material using standard technology. That is, when laying, builders use special glue instead of cement in order to avoid the appearance of cold bridges. At the same time, every fourth row of masonry made of such material is reinforced by specialists using steel rods with preliminary gating.
