Floor slabs are called horizontal structures, which perform the function of interfloor or attic partitions installed between the roof and the top floor of the house. In modern construction they usually resort to installing concrete floors, and it does not matter at all how many levels the building has. In this article we will look at the types and sizes of floor slabs that are most often used on construction sites. These products make up the main share of products produced at concrete factories.
Purpose of the design
Load-bearing structures are made from heavy or light concrete, and their structure is reinforced with reinforcement, which gives strength to the products. In today's market building materials all are represented standard types Reinforced concrete slabs, which can be divided into several categories depending on their width, length, weight, and others no less important parameters, affecting the main characteristics of products.
The most common method for classifying concrete panels is to divide them by cross-sectional type. There are also several more distinctive characteristics, which we will definitely consider in our article.
PC hollow-core reinforced concrete panels
These are some of the most common types of products produced at concrete factories, which are equally well suited for the construction of private and multi-storey building. Also, multi-hollow PC products are widely used in the construction of massive industrial buildings, with their help they provide protection for heating mains.
Hollow-core floor slabs are characterized by the presence of voids The smooth flat surface that round-hollow reinforced concrete panels have allows for the installation of reliable floors between floors that can withstand impressive loads. This design equipped with cavities with sections various shapes and diameter, which are:
- round;
- oval;
- semicircular.
Technological voids, which are filled with air during the installation process, are in high demand due to this feature, which indicates the advantages of this particular block configuration. TO undeniable advantages PC Refers:
- Significant savings in raw materials, which reduces costs finished product.
- High coefficient of thermal and noise insulation, improving performance characteristics the buildings.
- Round hollow panels are great solution for laying communication lines (wires, pipes).
Reinforced concrete structures of this type can be conditionally divided into subgroups, and then we will tell you what kind of hollow-core floors there are and by what criteria they can be classified into one or another subgroup. This information will be important for the right choice material depending technological requirements construction.
The slabs differ in the installation method: 1 PKT has three supporting sides, while 1 PKT can be laid on all four sides.
It is also necessary to pay attention to the size of internal voids - than smaller diameter holes, the more durable and stronger the round-hollow panels. For example, samples 2PKT and 1 PKK have similar width, thickness, length and number of supporting sides, but in the first case the diameter of the hollow holes is 140 mm, and in the second - 159 mm.
As for the strength of products produced by factories, their performance is directly affected by thickness, which on average is 22 cm. There are more massive panels with a thickness of 30 cm, and when pouring lightweight samples, this parameter is maintained within 16 cm, and in most cases lightweight concrete is used.
Separately, it is worth mentioning the load-bearing capacity of PC products. Mostly hollow-core PC floors, according to generally accepted standards, withstand a load of 800 kg/m2. For the construction of massive industrial buildings, slabs made of stressed concrete are used, this parameter is increased to a calculated value of 1200-1250 kg/m2. Design load is a weight that exceeds the same value of the product itself.
Manufacturers produce reinforced concrete panels of standard sizes, but sometimes the parameters can differ significantly. The length of the PC can vary in the range of 1.5 m - 1.6 m, and their width is 1 m, 1.2 m, 1.5 m and 1.8 m. The lightest and smallest floors weigh less than half a ton, while the most massive and heaviest samples weigh 4,000 kg.
Round-hollow structures are very convenient to use, because the developer always has the opportunity to select the material of the required size, and this is another secret of the popularity of these products. Having familiarized ourselves with the most common PC products, which include hollow-core floor slabs, and having examined their types and sizes, we suggest moving on to other products of a similar purpose.
Prefabricated ribbed (U-shaped) panels
Your name data reinforced concrete structures obtained thanks to a special configuration with two longitudinal stiffeners, and they are used in the construction of non-residential premises and as load-bearing elements for laying heating plants and water supply networks. To strengthen reinforced concrete products at the stage of pouring them, reinforcement is carried out, which, coupled with a special shape, leads to savings in raw materials, gives them special strength and makes them resistant to bending. It is not customary to install them as jumpers between floors for a residential building, since here you will have to deal with an unaesthetic ceiling, which is quite difficult to provide with communications and cover with cladding. There are also subtypes here; let’s look at the differences between products within the same group.
The ribbed slab design is highly durable
First and main distinctive feature U-shaped designs lies in their size, or more precisely, in terms of height, which is 30 or 40 cm. In the first case, we are faced with products that are used in the construction of public buildings and as bridges between the upper floor of the house and attic space. For massive, large-scale commercial and industrial buildings, slabs with a height of 40 cm are usually chosen. The width of the ribbed floors can be 1.5 or 3 m (for more durable samples), and their weight ranges from 1.5 to 3 tons (in rare cases up to 7 t). Prefabricated ribbed concrete plates characterized by the following length indicators:
- 12 m.
- 18 m (rare).
Solid additional structures
If it is necessary to obtain a particularly strong floor between the floors of a house, they resort to using solid lintels, since they can easily withstand a load of 1000-3000 kgf/m2, and they are mainly used during installation multi-storey buildings.
Solid lintels allow you to install a high-strength floor Such products have disadvantages, because their weight for relatively small dimensions is quite impressive: standard samples weigh from 600 kg to 1500 kg. They also have weak thermal and noise insulation performance, which does not allow them to compete adequately with hollow PC samples. The length of this type of panels ranges from 1.8 m to 5 m, and the thickness is 12 or 16 cm.
Monolithic structures
Previous and this species panels have the same scope of application and are installed where there is a need to create a strong building that can withstand heavy loads. Such a partition does not contain cavities and is created directly on the construction site according to available accurate calculations, so it can take on any configuration and dimensions, limited only by the area of the object being built.
In the article we described in detail what types of floor panels there are, what standard sizes they have and where they are used most often, so you can choose the necessary products for the upcoming construction and get a durable durable design, capable of serving you for at least a century.
Reinforced concrete slabs are used in building construction to redistribute loads from the weight of furniture, equipment, snow and other heavy elements directly onto the load-bearing walls or columns of the building. They divide the space of the structure transversely vertically or cover top floor for the manufacture of roofing.
Floor elements are used in the construction of large shopping and industrial complexes, entertainment centers, cultural and public premises, multi-storey residential buildings. In private construction, prefabricated reinforced concrete slabs They are successfully used for covering and covering the upper floors, creating a reliable and durable frame of the house.
According to the form of internal content, reinforced concrete products are divided into types: hollow and ribbed.
Depending on the thickness, cavity dimensions and method of support on load-bearing elements, hollow core slabs are divided into categories in accordance with GOST.
With different support method
a) 1pc thickness is 220mm, voids are formed with a diameter of 159 mm, support occurs on two sides, length from one and a half to six and a half meters, width from 1 to 3.5 m, 1 pct - support on three sides, 1PKK - trough four-sided support;
b) 2 pcs - slab height 220 mm, voids with a diameter of 140 mm, 2 pkt - support on three sides, length ranges from three to six meters, 2 pkt - four-sided support, length 2.5–6.7 m;
c) 3PK - 220 mm, voids are made diameter 128 mm, designations of the supporting sides are similar to the previous ones;
With support on only two sides
A) 4pcs slabs They are produced with a thickness of 260 mm, voids of 158 mm, in the upper belt there are cutouts along the entire contour. Cover spans up to 6 m, width up to 1.5 m;
b) 5 pcs- product body height 260 mm, hollow hole diameter 181 mm, length for spans up to 12 m, width 1.1 m, 1.25 m, 1.48 m;
V) 6 pcs plates are manufactured with a height of 300 mm, round voids of 204 mm are produced maximum length for large spans 12 m;
d) 7 pc-thickness products are provided 160 mm, round voids with a diameter of 115 mm, cover average spans up to 6.5 m, width 1.1 m, 1.25 m, 1.49 m, 1.81 m;
d) PG-voids pear-shaped, slab thickness 260 mm, purlin length 12 m, available in different widths, up to 1.5 m;
e) PB-series, produced using continuous forming technology on stands;
Ribbed floor slabs
In order to save light or heavy concrete mixtures Concrete was removed from the bottom layer of the slab, which does not work well under tensile loads, but has excellent resistance to compression. Under the influence of forces in top layer compression forces arise in the plates, and tension forces occur in the lower part.
Instead of concrete, slabs are provided along the entire length inserts from metal fittings , withstanding tensile forces. To accommodate them, stiffeners are made of concrete. In ribbed slabs, to cover spans of more than 12 m, transverse convex grooves are additionally made in accordance with GOST.
Ribbed reinforced concrete products are divided into series according to GOST
- 1P are called slabs that have two strips of support on separate shelves of the crossbar; they are available in varieties from 1P1 to 1P8;
- The support on the crossbar is designated 2P and is available in a single version;
- In slabs of the 1P1–1P6 series, GOST provides for the installation of embedded parts at the junction of the ends, if required by the drawing documents;
- Prestressing of reinforcement is carried out before concreting in product forms 1P1–1P6 and 2P1;
- The reinforcement is not stressed electromechanically during the manufacture of types 1P7 and 1P8.
An example of deciphering the designation of slabs according to GOST: 1P4– 2, At - VI P-1
- First three letters they talk about the standard size of the slab (1P4);
- Number 2 indicates the load-bearing capacity class of the product;
- At - VI is a typical designation of reinforcement from the assortment directory;
- The letters P and T determine the type based on the density of the concrete used in its manufacture. P-easy option, T-heavy concrete mixture.
The last digit separated by a dash shows the features of the view in the manufacture of reinforced concrete products. 1- the presence of various additional metal elements; 2-side ribs contain holes of 208 mm; number 3 indicates holes of different diameters on both sides;
Scope of application of reinforced concrete slabs according to GOST
GOST requirements for technical indicators
Finished slabs are subject to acceptance provided:
The overall dimensions of reinforced concrete products must comply with the standard approved technical documentation.
At the exit of the finished product, strength tests, crack resistance and rigidity. The indicators obtained during the experiments must not be lower than the normative ones provided for in the documents.
Parameters of compressive and bending strength, frost resistance, deviations in size from the norm are set out in the publication of GOST 13015.0–83;
The production and formation of the slab is carried out in strictly approved and developed forms. All metal embedded elements are manufactured from a certain class of steel, approved diameter. Processing is mandatory metal surfaces anti-corrosion compounds.
Concrete must meet the requirements according to GOST:
When manufacturing reinforced concrete products from lightweight concrete, its density per 1 m3 should be in the range of 1900–2100 kg. Heavy concrete density can correspond to 2250–2550 kg per 1 m3.
If the specification for the slab type specifies pre-tensioning of reinforcement, then it is released only after the concrete mixture has reached its design strength. Typically, this indicator is provided in whole days of hardening and is indicated in the drawing for the production of the slab or in the technical documentation for the building under construction.
Lightweight types of concrete mix necessarily correspond to porosity indicators, taking into account tolerances and deviations.
The quality of all local materials and binding components involved in the production of concrete mixture must be within standard limits in the relevant GOSTs.
When operating in an aggressive acidic or gaseous environment, the regulations for the production of products are determined in the documents for the building.
Conditions for conformity of reinforcing wire
GOST defines the name and classes of reinforcing steels permitted when using slabs in different operating environments. A separate list defines the types of steels that are not allowed for the production of products due to low technical parameters.
Metal mounting loops must withstand the weight of the hinge when moving, the embedded parts of the product, welded during the installation process, can take various loads up to working in extreme conditions. All elements laid in the concrete mixture must be calculated according to all indicators. Their shape, dimensions and diameter are clearly defined by GOSTs and are not subject to change.
Preliminary voltage reinforcing steel , by tension, electromechanically or mechanically.
The tension that arose in metal wire, is measured with special instruments, and it should not be lower than the nominal value by 10%.
Acceptance of finished products
The frost resistance of floor elements is checked by the labor control department on prototypes by large quantities freezing and thawing cycles. The results are recorded in special passports.
Porosity and water permeability thresholds are checked for each type of concrete mixture separately and documented in the necessary documents.
To be approved for use, the product undergoes a series of tests for strength, density, and hardness.
All metal elements are subject to visual and instrumental control for compliance with drawings, technical documentation and GOST. If necessary, a report is drawn up for hidden work on laying reinforcement.
Concrete porosity indicators must be exactly as in the project or in the order, comply with GOST.
The compliance of the slabs with the dimensions indicated in the drawings is carried out systematically and selectively. The surface is inspected in the same way for the appearance of microcracks.
Check the layer upon release protective concrete for metal on the edges of the slab using X-ray devices.
Rules for transporting floor slabs
All inscriptions indicating the brand of the slab, applied with contrasting color paint on the side or end surface so that they are visible when stacked on top of each other.
It is permitted to transport and deliver slabs to the construction site only if you have the appropriate passport indicating all technical specifications products.
For storage in hangars or outdoor construction sites slabs are stacked, not exceeding 2.5 m in height. A wooden spacer in the form of a beam measuring about 50x50 mm is made under each slab; wooden elements placed in corners or under protruding elements (for example, ribbed products).
The use of high-quality floor slabs is important when constructing a building. If damaged, cracked or bent products are used in violation of overall dimensions, the strength of the building frame will decrease, which in difficult conditions can lead to collapse.
Can only be used for styling factory-made products with documents. You can also install used slabs, but first obtain the results of testing and inspection by construction experts in accordance with GOST.
Looking at stacks of reinforced concrete slabs, the average citizen does not suspect how many important information they can inform the specialist - the builder. This is not surprising, because in Everyday life we rarely come across such designs.
If we are talking about a new building, then it will be useful for the customer of installation work to know what types and sizes of floor slabs exist, as well as what their maximum load bearing capacity according to GOST.
At first glance, the differences between hollow-core floor slabs are only in their length, thickness and width. However, the technical characteristics of these structures are much more extensive, so we will look at them in more detail.
State standard - a set of laws of strength
All basic requirements for hollow core slabs, including their purpose and strength characteristics, describes GOST 9561-91.
First of all, it indicates the gradation of the slabs depending on their thickness, the diameter of the holes and the number of sides with which they rest on the walls.
In addition to different thicknesses and geometric dimensions, hollow-core floor slabs are classified according to the method of reinforcement. GOST indicates that panels that rest on walls on 2 or 3 sides must be made using prestressed reinforcement.
The practical conclusion that follows from this for the developer is that you cannot punch holes for engineering Communication, violating the integrity of the working fittings. Otherwise, the slab may lose its load-bearing capacity (crack under load or collapse).
Clause 1.2.7 of GOST 9561-91 makes important exceptions, allowing for the manufacture of certain types of slabs not to install prestressed reinforcement in them.
They refer to the following panels:
- Thickness 220 mm with length 4780 mm (voids with a diameter of 140 and 159 mm);
- Thickness 260 mm, length less than 5680 mm;
- 220 mm thick, any length (voids with a diameter of 127 mm).
If such reinforced concrete floor slabs were brought to your site, and their passport indicates non-tensioned reinforcement, do not rush to send the car back to the factory. These structures comply with building codes.
Features of manufacturing technology
Floor slabs are made different ways, which is reflected in the quality of their front surface. PC and PG grade slabs are cast in formwork, and PB panels are made continuously on a conveyor line. The latest technology is more advanced formwork production, therefore the surface of PB slabs is more even and smooth than that of panels of the PC and PG brands.
In addition, conveyor production makes it possible to produce PB slabs of any length (from 1.8 to 9 meters). This is very convenient for the customer when it comes to so-called “additional” slabs.
The fact is that when laying out slabs on a building plan, several areas are always formed where they do not fit standard panels. Builders get out of the situation by filling in such “blank spots” monolithic concrete right on site. The quality is so homemade design noticeably inferior to that achieved in factory conditions (vibration compaction and steaming of concrete).
The advantage of PC and PG panels over PB panels is that you can punch holes in them for communications without fear of structural destruction. The reason is that their void diameter is at least 114 mm, which allows free passage sewer riser(diameter 80 or 100 mm).
PB slabs have narrower holes (60 mm). Therefore, to pass the riser, you have to cut the rib, weakening the structure. Experts say that such a procedure is unacceptable only for high-rise construction. When constructing low-rise housing, punching holes in PB slabs is allowed.
Advantages of hollow reinforced concrete slabs
There are a lot of them and they are all quite significant:
- Reducing the weight of building structures;
- The voids in the slabs dampen vibrations, so this type of flooring has good sound insulation;
- Possibility of laying communications inside voids;
- Fire resistance and moisture resistance;
- High speed of installation work;
- Durability of the structure.
Dimensions of hollow core slabs
Here everything is unified to the maximum so that it is possible to produce a structure of any installation size. The gradation of the width and length of the slabs occurs in increments from 100 to 500 mm.
Marking – passport of the floor slab
The developer does not need to know the intricacies of the technology used to produce a hollow-core floor slab. It is enough to learn how to correctly decipher the markings.
It is carried out in accordance with GOST 23009. The stove brand includes three alphanumeric groups separated by hyphens.
The first group contains data on the type of panel, its length and width in decimeters (rounded to the nearest whole number).
The second group indicates:
- Load-bearing capacity of the slab or design load (kilopascals or kilogram-force per 1 m2);
- For prestressed slabs, the class of reinforcing steel is indicated;
- Type of concrete (L - light, S - silicate, heavy concrete is not indicated in the markings).
The third group of markings contains additional characteristics that reflect the special conditions of use of structures (resistance to aggressive gases, seismic influences, etc.). In addition, the design features of the slabs (the presence of additional embedded parts) are sometimes indicated here.
As an example to explain the principle of marking hollow-core panels, consider the following design:
Hollow-core panel type 1PK, length 6280 mm, width 1490 mm, designed for a load of 6 kPa (600 kg/m2) and made of lightweight concrete using prestressed reinforcement class At-V).
Its marking will look like this: 1PK63.15-6AtVL. Here we see only two groups of characters.
If the slab is made of heavy concrete and is intended for use in a seismic zone (seismicity up to 7 points), then a third group of symbols appears in its designation: 1PK 63.15-6AtV-C7.
The considered technical characteristics of floor slabs determine their scope of application.
All types of hollow-core panels are calculated based on the standard load on the floor - 150 kg/m2 (weight of people, equipment and furniture).
Load bearing capacity standard plate is in the range from 600 to 1000 kg/m2. Comparing the standard of 150 kg/m2 with the actual strength of the panels, it is easy to see that their safety margin is very high. Therefore, they can be installed in all types of residential, industrial and public buildings.
|
Slab type |
Reduced slab thickness, meters |
Average density of concrete slab, kg/m3 |
Slab length, meters |
Building characteristics |
| 1pcs,1pkt, 1pcs |
up to 7.2 inclusive |
Residential buildings (sound insulation of premises is ensured by installing floating, hollow-core, hollow-core or layered floors, as well as single-layer screed floors | ||
| 1pc | ||||
| 2pk, 2pkt, 2pkk | Residential buildings in which sound insulation of residential premises is ensured by installing single-layer floors | |||
| 3PK, 3PKT, 3PKK | ||||
| 4pcs | Public and industrial buildings | |||
| 5pcs | ||||
| 6pcs | ||||
| PG | ||||
| 7pcs | Residential buildings (low-rise and estate type) |
This table contains the given thickness of the slab - a term not understood by beginners. This is not the geometric thickness of the panel, but a special parameter created to assess the efficiency of the slabs. It is obtained by dividing the volume of concrete placed in the slab by its surface area.
Approximate prices
Dozens of standard sizes are used in construction hollow core slabs, That's why detailed description Their prices would have to be devoted to a separate article. We will indicate the price parameters of the most popular panels (pickup):
- PC 30.12-8 – from 4,800 rub./unit;
- PC 30.15-8 – from RUB 5,500/unit;
- PC 40.15-8 – from RUB 7,600/unit;
- PC 48.12-8 – from 7,000 rub./unit;
- PC 51.15-8 – from RUB 9,500/unit;
- PC 54.15-8 – from RUB 9,900/unit;
- PC 60.12-8 – from RUB 8,200/unit;
- PC 60.15-8 – from 10,600 rub./unit;
Installation of hollow core slabs
The main condition quality installation panels, is strict adherence to the calculated parameters of support on the walls. Insufficient support area leads to destruction of the wall material, and excess area leads to increased heat loss through cold concrete.
Installation of floor slabs must be carried out taking into account the minimum permissible depth of support:
- on brick - 90 mm;
- for foam concrete and aerated concrete blocks— 150 mm;
- on steel structures— 70 mm;
- for reinforced concrete - 75 mm;
The maximum depth of embedding slabs into walls should not be more than 160 mm (brick and light blocks) and 120 mm (concrete and reinforced concrete).
Before installation, each slab must be filled with voids ( lightweight concrete to a depth of at least 12 cm). Laying the panel “dry” is prohibited. To ensure uniform load transfer on the walls, before laying, spread a mortar “bed” no more than 2 cm thick.
In addition to observing the standard support depths, when installing floor slabs on fragile blocks of gas or foam concrete, a monolithic concrete reinforced belt should be laid under them. It eliminates the squeezing of blocks, but requires good external insulation to eliminate cold bridges.
During the installation process, the deviation of the difference in elevations of the front surfaces of adjacent panels should be constantly monitored. This needs to be done at the seams. Don’t listen to builders who install panels in “steps” and tell you that it is impossible to lay them straighter.
Building codes establish the following tolerances depending on the length of the slabs:
- up to 4 meters – no more than 8 mm;
- from 4 to 8 meters – no more than 10 mm;
- from 8 to 16 m – no more than 12 mm.
Finished floor slabs belong to the category of precast reinforced concrete products. Widely used in the construction of multi-storey buildings and road construction. IN different types works, structures of certain dimensions and shapes are used. To facilitate the design and construction processes, the dimensions were brought to a single standard.
Characteristics
Reinforced concrete floor slabs are made from so-called structural (using coarse filler) heavy and light concrete mixtures. The main function is carrier.
Their popularity among builders is due to ease of installation, speed of installation and reasonable price. However, they are heavy, so the support must be much stronger than reinforced concrete. Besides concrete structure is not water resistant, therefore it cannot be stored for a long time under open air without waterproofing protection.
Available in 3 types:
1. Solid. Are different high level compressive strength, large mass and low sound and heat insulation properties.
2. Tents in the form of a tray with smoothed ribs. When using them, crossbars and similar beam elements are excluded from the project. They make it possible to simplify sound insulation and finishing of indoor surfaces, and raise the ceiling level without building up walls. The dimensions of the reinforced concrete hip-type floor slab are dictated by the length and width of the room, the standard height is 14-16 cm.
3. Void. This is the most popular type of concrete products. They are a parallelepiped with longitudinal voids of a tubular nature. Thanks to their design, they are considered more resistant to bending, can withstand significant loads - up to 1250 kg/m2, the dimensions are convenient for covering spans up to 12 m long, and the shape is suitable for laying communications.
Hollow-core floor slabs are marked:
- 1P – single-layer reinforced concrete product – no more than 12 cm.
- 2P - similar to the previous one, but the thickness is already 16.
- 1PK – multi-hollow reinforced concrete products with internal cavities with a diameter of up to 16 cm. Height – up to 22 cm.
- 2PK – the same with void cross-section up to 14.
- PB is a hollow structure with a thickness of 22.
Standard dimensions hollow-core floor panels according to GOST 26434-85 are given in the table below.
The weight of the finished product reaches 2500 kg.
The marking of the floor slab contains full information: type, dimensions, compressive strength. For example, PC 51.15-8 is:
- PC is a multi-hollow panel with tubular longitudinal cavities with a diameter of 15.9 cm, height - 22 cm.
- 51 – length in dm, that is 5.1 m.
- 15 – width in dm – 1.5 m.
- 8 is the load it will withstand. IN in this case– 800 kgf/m2.
In addition to standard ones, solid floor slabs made of cellular concrete (aerated concrete and others) are produced. They are quite light, can withstand light loads - up to 600 kg, and are used in low-rise construction. To create a strong connection, manufacturers produce tongue-and-groove products (tenon and groove).
Installation of prefabricated slabs
Before laying, all bases are leveled and, if necessary, reinforced with a ring reinforced belt from monolithic reinforced concrete a width of at least 25 cm, a thickness of 12 cm. The differences between opposite main walls should not be more than 1 cm.
Prefabricated concrete products are stacked closely using lifting equipment, the gaps are filled with mortar. To connect into a rigid monolith, the anchoring method is used.
When installing, the slabs must rest on the main wall or foundation with a section of the panel at least 15-20 cm wide. The gaps between the reinforced concrete and interior partition laid with bricks or lightweight concrete blocks.
Cost of concrete goods
Due to the fact that the composition of the ceiling and dimensions are standardized, the policy of enterprises is aimed at maintaining a stable price. average cost hollow core panels is shown in the table below.
| Name | Parameters, cm | Price, rubles |
| PC 21.10-8 | 210x100x22 | 2 800 |
| PC 21.12-8 | 210x120x22 | 3 100 |
| PC 25.10-8 | 250x100x22 | 3 300 |
| PC 25.12-8 | 250x100x22 | 3 700 |
| PC 30.10-8 | 300x100x22 | 3 600 |
| PC 30.12-8 | 300x120x22 | 4 000 |
Hollow-core reinforced concrete floor slabs are one of the most popular types of reinforced concrete products, intended for separating building levels and laying load-bearing structures. Specifications and standards are controlled by GOST 9561-91, their characteristics allow them to be used in any area of construction: from private houses to industrial facilities. Mandatory application nuances include the use of lifting equipment for laying and checking the load-bearing capabilities. It is easy to select the desired series; the labeling includes all the necessary information.
Externally, multi-hollow panels are a rectangular box with regular geometry of walls and ends, with longitudinal reinforcement, round or pear-shaped internal cavities located at equal intervals. For their production, heavy, light and dense silicate grades of concrete are used (for load-bearing systems their strength class is not lower than B22.5). The voids are located parallel to the main direction along the length (for types based on 2 or 3 sides) or to any of the sides of the contour for floors marked PKK.
The presence of a frame is mandatory; to extend the service life and enhance reliability, all metal placed inside is treated with anti-corrosion compounds at the manufacturing stage. The panels, supported on 2 or 3 sides, contain a frame of prestressed reinforcement. Depending on the purpose of the floor slabs, one of the following grades of steel is used: seven-wire strands with a section of 6P-7, periodic profile 5Vr-II, K-7 ropes, thermally strengthened At-V rods and other materials that comply with the standard (series 1 141.1 - main document regulating the process of release and quality control of products).
To the main technical specifications include:
1. Dimensions and weight of structures. The thickness is standard and unchanged (for most types - 220 mm), length varies from 2.4 m to 12, width - within 1-2.6 m. The exception is types supported on 4 sides (PKK marking), their dimensions vary from 3×4.2 to 3×7.2 m, respectively. Average weight 1 l.m. with a width of 1 m it is 360 kg.
2. Load-bearing capacity. Depending on the grade of concrete and the intensity of reinforcement, slabs with voids can withstand from 450 to 1200 kg/m2. The standard value for the most popular series with round holes is 800 kg/m2, if it is necessary to exceed it, products are made to order.
3. The fire resistance limit of hollow-core panels is 1 hour; if necessary, it is increased by strengthening the reinforced frame.
The structures are valued for their reliability, light weight, good tensile bending strength due to the presence of internal voids, the ability to hide communications, resistance to moisture, open fire, biological influences, heat and soundproofing properties, durability. An important advantage high geometric accuracy is considered, simplifying the process of installation and subsequent finishing.
| Type | Actual thickness, mm | Length (maximum, inclusive), m | Reduced slab thickness (ratio of concrete volume to area) mm | Diameter of voids, mm | Nominal distance between void centers, not less than mm |
| 1pc, 1pkt, 1pkk | 220 | 7.2 (up to 9 for slabs for industrial buildings, supported exclusively on 2 sides) | 120 | 159 | 185 |
| 2pk, 2pkt, 2pkk | 7,2 | 160 | 140 | ||
| 3PK, 3PKT, 3PKK | 6,3 | 127 | |||
| 4pcs | 260 | 9,0 | 159 * | ||
| 5pcs | 12 | 170 | 180 | 235 | |
| 6pcs | 150 | 203 | 233 | ||
| 7pcs | 160 | 7,2 | 90 | 114 | 139 |
| PG | 260 | 12 | 150 | ||
| PB | 220 | Depends on molding parameters | |||
*there are additional cutouts in the upper zone.
The main standards for width are PK-10, PK-12 and PK-15. All types have holes round shape, the exception is PG - slabs with pear-shaped voids. For options marked PKK, beveled ends are allowed.
All dimensions of reinforced concrete floors with holes inside are unified (including length spacing), deviations do not exceed 5 mm. The thickness indicated in the table characterizes the cost-effectiveness of the product.
Marking of hollow core slabs
Standard decryption includes:
1. A number characterizing the size of the diameter of the internal holes according to GOST 9561-91. Omitted for 1 PC; in most price lists there is a simple designation - PC.
2. Type. Indicated by 2 or 3 letters, contains information about the shape of the voids, the manufacturing method and the number of supported sides. Of all varieties, PB is produced by continuous molding.
3. Dimensions of hollow-core floor slabs: the first is the length (of the side not supported by bearing structures), then the width, in dm, rounded up. The thickness is not indicated; this value depends on the type of product. Actual sizes always less: 20 mm in length, 10 in width.
4. The fourth mandatory point is a number reflecting the load-bearing capacity of the reinforced concrete product.
5. Type of reinforcement. Can be skipped for non-tensioned frames.
6. Brand of solution: not indicated for heavy solution, used in the majority of products. The letter L means the use of lightweight concrete, C - dense silicate.
7. Other, additional characteristics or design features of products. These include resistance to seismic influences or aggressive gases, and the presence of embedded elements.
Scope and features of application
The main purpose is to organize a reliable prefabricated floor in buildings with load-bearing walls(also used in construction). In private and low-rise construction, they are used for laying the main floors, dividing floors and attic space, and arranging pitched roofs V outbuildings, platforms and as a fence. Their load-bearing capacity fully corresponds construction requirements (standard rate when calculated taking into account the weight of people and furniture, it is 150 kg/m2, the actual value exceeds it several times). Soundproofing characteristics make it possible to provide reliable protection from noise even when installing single-layer floors.
Long slabs (up to 9 m for 1 pcs, 12 for 4 pcs, 5 pcs, 6 pcs and PG) are intended for installation in public buildings, the rest are considered universal and are recommended for residential buildings, including individual ones. When choosing dimensions, the need to comply with the standard for laying on supports is taken into account - from 7 to 15 cm, depending on the material of the walls (minimum - for dense brick, maximum - for aerated concrete). When converted into squares, the cost of 1 m2 for floors 1 m wide is more expensive than for products with 1.2 or 1.5 m, this is explained by the ban on cutting them crosswise. The use of concrete products of the PC series allows:
- Get reliable design, designed for significant weight loads.
- Improve the building's insulation capabilities.
- Ensure a perfectly flat horizontal floor (with correct placement and checking supports).
- Improve the waterproofing, fire safety and acoustic protection of the building.
Cost of slabs for installation of floors
| Series | Load-bearing capacity, kg/m2 | Dimensions (length×width×thickness), mm |
Weight, kg | Price for 1 piece, rubles |
| PC 16.10-8 | 800 | 1580×990×220 | 520 | 2 930 |
| PC 20.12-8 | 1980×1190×220 | 750 | 4 340 | |
| PC 30.10-8 | 2980×990×220 | 880 | 6 000 | |
| PC 36.10-8 | 3580×990×220 | 1060 | 6 410 | |
| PC 45.15-8 | 4480×1490×220 | 2120 | 12 600 | |
| PC 60.18-8 | 5980×1780×220 | 3250 | 13 340 | |
| PC 90.15-8 | 8980×1490×220 | 4190 | 40 760 | |
| 2PC 21.12-8 | 800 | 2080×1190×220 | 950 | 3 800 |
| 2PK 62.10-8 | 6180×990×220 | 2425 | 8 730 |
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