Diaphragms of rigidity in frame buildings: purpose, design, fixing and installation

When most people hear the expression "frame house", they represent a wooden structure. However, there are buildings built on frame-monolithic technology, which are based on concrete. The metal profile or reinforced concrete structures may be used for the work. The frame is sheathed with cement-particle boards, and the walls themselves can be made of blocks or bricks. It is important to remember that such buildings require the installation of a diaphragm of rigidity, the design features of which will be discussed below.

Appointment

Between the columns to the full height of frame structures, vertical wall panels are installed. The latter at the top can have shelves for installing slabs.

These elements connect with each other and with each other column panels, while they provide spatial rigidity to the entire structure. They must be in buildings in all directions in such a way that an intersection occurs and T-shaped or L-shaped figures are formed. Their fastening with columns is carried out on a height of at least three points. At the same time, welding of embedded parts is used. Diaphragms of rigidity are most often installed on tape foundations, in some cases monolithic slabs stand out as bases.

Design

Diaphragms, which are used to increase the rigidity, can have a different type of construction, among them we can distinguish:

• Two-lane;
• Single-columned;
• Solid;
• With doorways;
• Compound;
• With ventilation ducts.

In the latter case we are talking about diaphragms, which are ventilation units. Panels for such diaphragms are made of concrete of class M-300, this applies to the lower floors of the building, whereas for the latest ones a solution of the M-200 grade is used.

Diaphragms of rigidity can be manufactured in different periods of the year. If the work is carried out in the summer, then the strength of concrete should be 70% of the design, while in the winter season this figure should reach 100%. The reinforcement of reinforced concrete prefabricated panels is made from the lower and upper racks, and also the reinforcement block, which has enlarged dimensions. If the frame height does not exceed 3 m, and the design of the diaphragm does not have doorways and other openings, the frame can be lightened.

What else is necessary to know about the design features

Diaphragms of rigidity can have in their composition openings for reinforcement along the perimeter. In this case, the concentration of stress in the corners should be taken into account. The main task in this case is the collection of pylons rigidity. It is important to perform calculations of geometric parameters and check whether the strength is consistent with the characteristics. The analysis should also be subjected to the existing efforts in the constructions. Whatever the design features of the stiffening diaphragms, they are designed for central compression, as well as shearing forces from horizontal and vertical loads. If there are openings, then the elements should be checked for a joint effect of the voltage in the upper part of the wall.

Features of fastening of diaphragms of rigidity

Monolithic stiffening diaphragms must be in the span between the columns, their connection to each other is carried out using a monolithic deadbolt, it is mounted on the upper part of the diaphragm. The latter should extend along the entire height of the building, and in some cases, it is possible that the elements are not installed on the technical floor.

The lower floor must be supported on the foundation foundation with the help of embedded parts. In order to ensure the stability of the building, the diaphragms are installed in both directions. Vertical should be placed on the plan evenly, they are combined with the fences of lift units. The stiffening diaphragm in frame buildings must be installed in an amount of at least three in one temperature block. The geometric axes of these elements should not intersect, the center of gravity must coincide with the center of gravity of the axis of construction.

In order to increase the spatial rigidity of the building, which has an increased number of storeys, it is necessary to provide measures ensuring the compatibility of the operation of the diaphragms with the frame. This can be achieved by the method of making a keyway between the column and the diaphragm.

Installation Recommendations

In order to have the most durable wall, the stiffening diaphragm should be present in the building. If we are talking about the AI-04 series, then in the upper corners of such products there must be scrapes, on which the column consoles will later be placed. In addition, in the corner of the diaphragm there are outlets of steel rods. To fix the diaphragm of this series a closed loop is used on the frame of steel rods, the diameter of the latter can vary from 12 to 28 mm. The rods are always welded, which guarantees additional strength of the structure.

A series of diaphragm stiffness can look like 1.020-1, in this case on the elements there are no angular scores. Such structures are reinforced with special vertical frames, and along the perimeter of the construction a steel mesh is fixed, the diameter of its rods can vary from 5 to 12 mm, while the cells have a size of 200 mm. The diaphragms of this series are installed parallel with respect to the crossbars, and afterwards these building elements are replaced.

Conclusion

Those diaphragms, which are located in parallel with the bolts, are deprived of additional consoles. On the vertical faces of the AI-04 there are places by which the structural skeletons will be connected to the columns. If you use a diaphragm series 1.020-, then for it you should prepare the embedded parts.

It is worth mentioning also that the diaphragms are called hardness cores, and represent one of the main elements of buildings of any purpose. As the task of this component is the perception of horizontal loads by the type of seismic and wind, which affect the building.