- Concrete panels in civil engineering
- Modular system device
- Suitable types of bases
- Heat protection and heating of the house
- Engineering Communication
- Layout and finishing
- Technology specific features
It is believed that prefabricated home kits are of a much higher quality than locally assembled ones. Factories produce several types of houses, one of them is a prefabricated monolithic structure, has a more technological method of production and is less susceptible to the influence of the human factor.
Concrete panels in civil engineering
Who else, if not residents of the former socialist camp, know everything about panel buildings? The apartment buildings of the Khrushchev and Brezhnev era are familiar to almost everyone here, as are their inherent shortcomings. Because of this, the technology of panel housing construction has become notorious, and private developers shrug their shoulders in bewilderment when they are offered the construction of a house using prefabricated monolithic technology. And yet there is a big difference in whether the technology is used to fulfill the state order for a large number of cheap housing, or it is updated with the use of modern materials, design and architectural solutions..
The disadvantages of panel houses known to many are not typical for modern buildings. For example, the problem of sealing and insulating joints between panels is eliminated by a high-precision manufacturing method: for panels about 3 meters high and 5-6 meters wide, millimeter tolerances apply. After the panels are delivered to the construction site and assembled together, along all the abutment lines, the structural elements adjoin closely without the formation of cold bridges and gaps in sound insulation.
Many useful technical solutions are hidden in the very structure of the panels. Unlike traditional concrete products, modern modules for building houses are composite. They include a core made of high-strength reinforced concrete, two belts of thermal insulation, as well as stiffening ribs, which are used in combination to fix finishing materials. Manufacturers have developed many solutions regarding the appearance of buildings: from the outside, the panels imitate the appearance of a wide variety of types of facade finishes, sometimes a similar approach is demonstrated with respect to internal surfaces. Finally, we must not forget that in the modern view, a panel house is supplied to the customer in the form of a ready-made pre-fabricated kit, which provides everything: from utilities to individual planning features..
Modular system device
It is worth starting your acquaintance with low-rise panel houses with the basic design model. The scheme of assembly, fastening and execution of critical units in modern house kits is radically different from the one that was used in the construction of the municipal housing stock.
The main element of such a house is an energy efficient concrete panel. Its size and shape can be very different, with almost all panels from the set they are unique. The panel design necessarily provides for three points:
- Precise geometry and uniform layer thickness.
- Availability of technological units for monolithic connection with other panels.
- Openings, glazing, channels for communications, supporting finishing subsystem, etc..
Distinguish between panels of vertical and horizontal orientation, the latter are used for the construction of floors. In both cases, the edges of the panels have a special profile for a precise fit and a very strong bond, while at the junction of the panels there are no cold bridges and gaps in sound insulation. As a result, a rigid and stable monolithic box is obtained, clothed with a continuous heat protection belt, which is protected by a layer of facade decoration.
It is important to understand that the panel technology itself ends there, because the roof, foundation, system of internal partitions and communications can be completely different. Therefore, any additions from a plant that produces panels for construction is nothing more than an attempt to create a more or less complete image and offer the buyer a turnkey solution. At the same time, every conscientious manufacturer will always readily supply only one box, the junction points of which are focused on merging with a certain type of foundation and roof..
Suitable types of bases
Due to its high rigidity, a concrete panel house is less susceptible to the influence of geomorphological disturbances. For example, if one of the corners of the foundation begins to wash away, the house will not tilt, while buildings made of block materials will inevitably crack on a flexible foundation. Due to this, most panel houses are erected on the MZLF, and in regions with a large freezing depth – on bored piles connected by a grillage. In both cases, the foundation is backfilled with ASG or expanded clay.
In general, the geology of the site must be carried out without fail. The costs of soil research against the background of the entire construction budget are scanty, but they give confidence in the chosen type of foundation, and sometimes even allow you to change your mind and save money. For example, with a high ground water level or on weak soils, it is much more correct to arrange an insulated slab. Also, the house may require a basement, which is much easier and more correct to cast using monolithic technology, and then insulate.
There are also types of foundations that cannot be recommended for a panel house. These are, first of all, screw piles: they will require a fair amount and a large number of additional ties. In addition, the building on the VS has no natural thermal protection of the soil, and therefore will be less energy efficient. It is also undesirable to build on prefabricated foundations: they work well with a large mass and therefore require more time for shrinkage, while the installation of panels can be carried out 28 days after the completion of monolithic work. Thus, on a tape with backfilling or a slab, the construction of a turnkey house can actually be completed in one season..
Heat protection and heating of the house
Composite panel manufacturers have borrowed insulating ideas from Finnish frame technology. The presence of a continuous thermal break – an interlayer of foamed synthetic insulation – ensures that the temperature of the internal walls is maintained at the level regulated by SNiP and SanPiN, that is, no more than 3 ° C below the room air temperature.
There is also a basic thermal protection belt. It can be located both between the stiffening ribs of the slab, and from the outside. There are many types of panels, there are also concrete products with a pre-installed supporting system of a ventilated facade. The thickness of the insulation can reach 180-200 mm, and all the junctions between the walls and ceilings are protected from freezing by additional heat-insulating inserts. The right to choose a heater, as a rule, is given to the customer, however, in the case of using expanded polystyrene, fire-prevention cuts made of mineral wool will be installed.
The choice of heating method is also free. Since the house stands either on an insulated foundation or on a floor slab, it makes sense to heat the first floor with a water-heated floor. Floor heating can also be arranged on the second floor, but this is usually not required: after the building reaches the nominal thermal regime, almost the entire overlap area acquires room temperature. Therefore, on the second floors and attics, radiators or convectors are usually installed..
As for the heat loss at home, they are one of the lowest. The only competitor in this matter is aerated concrete houses insulated with mineral wool from 100 mm. However, at the same time, panel technology does not require pouring armo-belts and lintels over the openings, and the glazing is inserted in the factory with insulation and insulation of the entire abutment contour.
One of the features of modern panels is the presence of channels for laying communications. The inner surface of the walls and the bottom of the slabs have stiffening ribs, in which crimped holes are made for wiring, hidden plumbing and ventilation.
The ventilation system should be said separately, because the need for forced air exchange is one of the main problems of sealed panel houses. For the ventilation device in each house, a technical well is provided, in which one or more booster pipes of the exhaust flow are installed. In this case, the well adjoins the outer wall, due to which it becomes possible to install a recuperation system.
The lower supply lines of communications are carried out through the foundation. The same applies to the electrical network: it is better to lay the cable in the ground in advance than to subsequently make holes in the panels themselves. The peculiarity of panel technology is that all places for the output of communications are known in advance, and therefore the installation process itself takes a minimum of time and is not accompanied by dirty work.
The situation is somewhat different in houses assembled from panels with increased energy efficiency. Their inner surface is concrete, that is, the laying of communications is not provided for the enclosing structures. But there is a way out of this situation: the number of cables and pipes in the outer walls is reduced to a minimum, using ceilings and non-capital partitions for this purpose. If laying on the outer walls is required, the communications are placed in strips, as in an ordinary panel house.
Layout and finishing
As already mentioned, all technical conditions are provided for the installation of partitions, regardless of the technology used. These can be GKL frame systems, gas silicate blocks, brick or gypsum panels. But not all options are equally good, so the type of partitions must be chosen with an eye to the features of the supporting structure of the house..
To begin with, the floors in panel houses have a minimum deflection under load and excellent sound insulation. This is a natural advantage of monolithic floors: not a single frame system, especially without a screed, will be as stable and silent. Therefore, there is no need to worry about the propagation of noise between floors..
Instead, doorways and portals should be properly positioned to minimize airborne sound propagation. Rooms with natural high noise, such as bathrooms, are best separated with masonry material, for example, gas blocks. This method not only provides a finished surface for tiling, but also allows you to equip an external false wall with a filler. The described design has a noise damping efficiency of at least 50 dBA.
Partitions between rooms are usually made of plasterboard. They are built on a double-row frame with flexible ties, the walls are double clad and filled with mineral wool or padding polyester. This method of the device allows you to ensure the uniformity of the base on all planes and unify the finishing process. Of course, if the inner surface of the panels is concrete, it would be much more correct to lay out partitions made of gas silicate or gypsum boards.
Technology specific features
After a story about such wonderful houses, a logical conclusion should follow about the exorbitant cost of such buildings. But by no means: the cost of a concrete panel house kit is comparable to the cost of domestic crafts, called Finnish houses. At the same time, a house made of panels will cost about half the price of the original Finnish kit and will not be inferior to it either in energy efficiency, or in the comfort of living, or even in appearance..
The development of panel technology in civil engineering is a good opportunity for those who are willing to pay a little more just to guarantee the quality of the final result. In the case of houses made of composite panels, the result of investments will be exactly two things: two full-fledged floors with heat losses of 30–35 W / m2, completely suitable for permanent residence, as well as reducing participation in the construction process to almost zero with a guarantee of a fast speed of erection of a box with glazing and roofing.