When most people hear the expression "frame house", they imagine a wooden building. However, there are buildings erected using frame-monolithic technology, which are based on concrete. A metal profile or reinforced concrete structures can be used during 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 provide for the need to install a stiffening diaphragm, the design features of which will be discussed below.
Destination
Vertical wall panels are installed between the columns for the entire height of frame buildings. The latter may have shelves in the upper part for installing floor slabs.
These elements connect the column panels to each other and to each other, while they provide spatial rigidity to the entire building. They must be located in buildings in all directions in such a way thatthere was an intersection and T-shaped or L-shaped figures were formed. Their fastening with columns is carried out in height at least at three points. In this case, welding of embedded parts is used. Stiffening diaphragms are most often installed on strip foundations, in some cases monolithic slabs act as bases.
Design
Diaphragms that are used to increase rigidity can have different types of construction, among them are:
- two-shelf;
- single-shelf;
- solid;
- with doorways;
- compound;
- with ventilation ducts.
In the latter case, we are talking about diaphragms, which are ventilation blocks. Panels for such diaphragms are made of M-300 class concrete, this applies to the lower floors of the building, while the M-200 grade mortar is used for the most recent ones.
Stiffness diaphragms can be produced in different periods of the year. If work is carried out in the summer, then the concrete strength should be 70% of the design, while in the winter season this figure should reach 100%. Reinforcement of reinforced concrete prefabricated panels is made from lower and upper racks, as well as a reinforcing block, which has enlarged dimensions. If the height of the frame does not exceed 3 m, and the diaphragm design does not have door or other openings, then the frame can be lightweight.
What else you need to know about the design features
Stiffness diaphragms may have in theirconsisting of 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 stiffening pylons. It is important to carry out calculations of geometric parameters and check whether the strength corresponds to the characteristics. The acting forces in the structures should also be analyzed. Whatever the design features of stiffening diaphragms, they are designed for central compression, as well as shear forces from horizontal and vertical loads. If openings are present, the elements should be checked for joint stress at the top of the wall.
Features of fastening stiffness diaphragms
Monolithic stiffening diaphragms should be located in the span between the columns, their connection to each other is carried out using a monolithic crossbar, it is mounted on the upper part of the diaphragm. The latter should extend over 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 should rest on the foundation grillage with the help of embedded parts. In order to ensure the stability of the building, diaphragms are installed in both directions. The vertical ones should be evenly placed according to the plan, they are combined with the fences of the elevator units. The stiffness diaphragm in frame buildings should be installed in the amount of at least three in one temperature block. The geometric axes of these elements must not intersect, the center of gravity mustcoincide with the center of gravity of the axis of the building.
In order to increase the spatial rigidity of a building that has an increased number of storeys, it is necessary to provide measures to ensure the compatibility of the diaphragms with the frame. This can be achieved using a keyed connection between the column and the orifice.
Installation recommendations
In order for the wall to be as strong as possible, a stiffening diaphragm must be present in the building. If we are talking about the II-04 series, then in the upper corners of such products there should be undercuts, on which consoles of the columns will subsequently be placed. In addition, there are outlets of steel rods in the corner of the diaphragm. To fix the diaphragm of this series, a closed loop is used on a frame made of steel rods, the diameter of the latter can vary from 12 to 28 mm. The rods are always welded for added strength.
The stiffness diaphragm series may look like 1.020-1, in this case there are no corner cuts on the elements. Such structures are reinforced with special vertical frames, and a steel mesh is fixed along the perimeter of the structure, the diameter of its rods can vary from 5 to 12 mm, while the cells have a size of 200 mm. Diaphragms of this series are installed parallel to the crossbars, and then replace these building elements.
Conclusion
Those diaphragms that are parallel to the crossbars are devoid of additionalconsoles. On the vertical edges of II-04 there are places with the help of which the structural frames will be connected to the columns. If you will be using the 1.020-series diaphragm, then you should prepare embedded parts for it.
It is also worth mentioning that diaphragms are called stiffening cores, and are one of the main elements of buildings for any purpose. The task of this component is the perception of horizontal loads by the type of seismic and wind that affect the building.
