There are many methods for the construction of residential and industrial buildings. And one of the most inexpensive technologies to build reliable and durable structures is frame. The basis of buildings constructed in this way is a solid skeleton. Different materials may be used to assemble such load-bearing structures. For example, often enough buildings are erected on a reinforced concrete frame.
When can technology be used?
Buildings on reinforced concrete frames can be used for buildings of absolutely any purpose. This technology is great for building both residential buildings and production halls. Most often, multi-story buildings are erected on reinforced concrete frames. According to the regulations, such a technique can be used for the construction of houses up to 25 floors high. Also just perfect this technology is suitable for the construction of workshops of a large area.
In some cases, the construction methodology on reinforced concrete frames can also be used for the construction of one - two-story buildings. Most often, low-rise production shops and warehouses are, of course, built on such cores. But sometimes the owners of suburban areas use similar 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 such a design look very solid and presentable.
Varieties
Only three main types of reinforced concrete frames can be used in construction:
- national teams;
- monolithic;
- prefabricated monolithic.
The first type of cores is assembled from ready-made, manufactured at the enterprise heavy reinforced concrete beams, columns and ties. Monolithic frames of this type are poured directly at the place of construction of buildings. Under the structural elements of the cores of this type, formwork is pre-assembled.
Prefabricated reinforced concrete frames, in turn, by the installation method can be:
- framed;
- connected;
- combined.
Advantages and disadvantages
The main advantage of building buildings on reinforced concrete frames, as on any other, is the freedom of layout. Spans in such structures can be both narrow and very wide.
Of course, their cheapness can be considered an absolute advantage of buildings on a reinforced concrete frame. Such houses weigh less than brick, ordinary panel and block. Therefore, they do not need to build too powerful expensive foundations.
The advantages of this technology include the ability to:
- the construction of very durable buildings;
- arrangement of premises of a large area.
In comparison with metal and wooden frames, reinforced concrete are characterized by increased strength. Also a plus of such load-bearing structures is, of course, considered that they do not belong to the category of fire hazardous.
Some disadvantage of precast reinforced concrete frames is the need to use expensive special equipment for the installation of individual elements. The minuses of monolithic structures of this type include lengthening the construction period. Concrete matures, unfortunately, for quite a long time - about a month. That is, the floors of buildings using this technology of assembly of the frame have to be erected intermittently. Builders need to wait until the supports gain sufficient strength to support the weight of heavy floors.
Reinforced concrete frame elements: columns
Finished reinforced concrete products intended for the erection of such buildings are usually made in factories from concrete grades 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, communications and crossbars of different sections and strengths are used in construction.
For example, in the construction of reinforced concrete frames of industrial buildings, the floors of which in the future during operation will be subjected to severe loads, columns 1.020 are used. Such structural elements can withstand loads of up to 500 tons.
During the construction of buildings, two types of reinforced concrete columns can be used:
- ordinary;
- used for workshops with bridge cranes.
The columns of the latter variety consist of two parts: a crane and a 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 the spans.
The height of the column precast concrete frame can have one, two or many floors. In the form of such elements are:
- cantilever;
- unconsolidated;
- T-shaped;
- L-shaped.
In construction, reinforced concrete columns with a square, round, annular or rectangular cross section can be used.
Horizontal elements
Reinforced concrete beams used in the construction of prefabricated reinforced concrete frames of buildings are classified into base and interfloor. Elements of the first variety are usually in the form of an I-beam. Their height can be 400 or 600 mm, and the width in the upper part 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.
Cross-section beams of reinforced concrete frames of houses in cross section can be:
- Tauri;
- rectangular;
- Z-shaped.
They can have a length of either a span or several, or a step between the columns.
Communications
Such elements of reinforced concrete carcasses of buildings can be made of cement mortar using reinforcement or steel. They are necessary in order to provide spatial rigidity of the building. Communication can be established both in horizontal and in vertical position. In some cases, they can also be mounted diagonally.
Foundations
Frame buildings are being erected on prefabricated base-blocks, which are a "glass" with a stove. Preparation for the foundations of such houses on dry soils is done from crushed stone, and on wet soils - from concrete of grade 500.
During construction, the upper plane of the foundations of this type is placed 150 mm below the fair floor mark. This installation method allows subsequently to backfill the pit before installing the columns.
Under the outer walls, the foundation beams are laid so that they extend 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.
Mounting frame assembly methods
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 cores by welding metal fittings.
In frame-communication frames, reinforced concrete frames perceive only vertical loads. Horizontal in such structures fall on the floor. The latter, in turn, transfer loads to flights of stairs. Also in this case, transverse and end walls are involved.
In the articulated-link frames, the loads are distributed in the same way as in the frame-link. The only thing is that the fastenings between the elements in this case are not rigid, but hinged.
Beamless frames
Such structures are assembled in the form of a grid of 6x6, 9x6 or 9x9 m. In this case, the first is the most popular option for frames. The main elements of such reinforced concrete frameworks are:
- columns with capitals;
- span plates;
- window sills.
They are erected on such frames of the building much less often than on girders. Use this technology mainly only in the construction of industrial buildings with high requirements for cleanliness. For example, workshops of dairies and bakeries, as well as refrigerated warehouses are often built using this technology.
The frames of this variety are being built using a very simple technology. Interfloor slabs in this case are simply stacked on the capitals of the columns and additionally fixed.
Prefabricated monolithic frames: construction
On these skeletons, buildings are also constructed quite often. Ties in such constructions, as well as in prefabricated frame ones, are provided for rigid. Columns in the frames of this variety are used ready-made factory. Ceilings are poured directly on the spot 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 cheaper construction.
Technology for the construction of a monolithic frame
Under such frames, both slab foundations and strip or column foundations with grillages can be used. In this case, not only floor floors are poured into the formwork, but also columns. Using this technology, in most cases, not too large one- or two-story residential buildings are erected.
The methodology for building houses on a monolithic reinforced concrete frame includes the following steps:
- foundation construction according to standard methods;
- pouring columns;
- pouring floors.
Elements in monolithic reinforced concrete frames of one-story buildings are rigidly interconnected. No articulated joints are used in such constructions. The connection of the columns with ceilings and the foundation in this case is carried out by means of reinforcement followed by monolithic 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. For floors, the formwork in such houses is mounted on special telescopic factory racks located with a small pitch from each other. Also in this case, log supports of a sufficiently large cross section can be used.
The reinforcement cage in the reinforced concrete structures of the cores is made of thick steel rods. When assembling it, both welding and ordinary knitting wire can be used.
Interior and exterior walls
As the material for the building envelope on prefabricated or monolithic reinforced concrete frames, in our time, in most cases, foam blocks are used. The use of such a material has a number of obvious advantages. Foamed blocks do not weigh too much. They are usually large enough in size, which allows them to masonry as soon as possible.
Also, foam blocks are not particularly expensive, which can also be attributed to their advantages. In the premises of buildings with such walls, a very pleasant microclimate is usually created. You can lay walls between the columns of the reinforced concrete frame both from large blocks in one layer, and from small ones in several.
Walls are made of such material using standard technology. That is, when laying, builders use special glue instead of cement to avoid the appearance of cold bridges. Moreover, every fourth row of masonry made of such material is reinforced by specialists using steel rods with preliminary gating.