GOST for hollow core floor slabs. How are floor slabs marked? Ribbed floor slabs

Anyone who has at least once dealt with the construction of a house knows how important hollow reinforced concrete slabs or floor panels are. Hollow-core concrete floor slabs, in fact, make up about 90% of total weight Houses. Floor slabs (PC) can vary greatly in both weight and size, depending on the specific purposes for which they are used.

Structural features of hollow core slabs

As you might guess, the inside of reinforced concrete floor slabs (RC) are hollow, which is why they are labeled for sale as multi-hollow. But the holes inside such slabs, contrary to misconception, can have not only oval, but also round, square and other shapes.

Scheme of supporting a hollow core slab

However, in most cases, floor slabs (PCs) have cylindrical hollow circles inside.

Interestingly, floor slabs (PC) can be either unreinforced or reinforced. Reinforced concrete floor slabs (PC) will be reinforced.

Although such floor slabs (PCs) have significantly more weight, which ultimately increases both the load on the building and the cost of construction, however, they have a large margin of safety. Installation of floor slabs, namely the installation method itself, depends on what support the slabs will be placed on, because support is also an important criterion.

For example, if the support of the slab is not stable enough, this can lead to unpleasant consequences, which, of course, must be avoided.

Scheme of laying a hollow core slab on the second floor

Characteristics of hollow core slabs

Size

Its final cost also depends on the size of the hollow core PC; in addition to parameters such as width and length, weight is also important.

PC sizes vary as follows:

• the length of the PC ranges from 1180 to 9700 millimeters;
• The width of the PC ranges from 990 to 3500 millimeters.

The most popular and in demand are hollow-core panel slabs, the length of which is 6000 mm and the width of 1500 mm. The height or thickness of the panel is also important (it would be more correct to talk about height, but builders, as a rule, say “thickness”).

So, the thickness that they can have hollow-core panels, is always the same value - 220 mm. Of course, the weight of the floor panel is also of great importance. Concrete floor slabs must be lifted by a crane with a minimum lifting capacity of 4-5 tons.

Comparative table of coordination sizes of hollow core floor slabs

The length and weight of the panels are vital importance for construction, length is an even less important indicator than weight.

Weight

As for such an important parameter as weight, everything is very clear the first time: the range of products produced in Russia ranges from 960 kilograms to 4.82 tons. Weight is the main criterion by which the method by which the panels will be installed is determined.

Typically, cranes are used, as noted above, with a lifting capacity of at least 5 tons (of course, cranes must lift weight with some margin).

The weight of panels with the same markings may differ, but only slightly: after all, if we consider the weight with an accuracy of one gram, anything can affect it.

Comparative characteristics main brands of hollow core slabs

If, for example, a product is caught in the rain, then it will a priori be slightly heavier than the product that was not exposed to rain.

Types of loads

To begin with, it should be noted that any overlap requires the presence of the following 3 parts:

1. The upper part, with the floor where people live. Accordingly, the panel will be loaded by the floor covering, various insulating elements and, of course, concrete screeds - the main component of the load;
2. The lower part, with the presence of the ceiling, its decoration, lighting fixtures. By the way, you shouldn’t be skeptical about the availability of lighting fixtures. Firstly, the same LED bulbs requires partial destruction of the slab with a hammer drill to lay the cable. Secondly, if we take large premises, with columns and halls, huge crystal chandeliers can hang there, which will give more load than any other device or type of decoration. This must also be taken into account;
3. Structural. It unites both the upper and lower parts at once, as if supporting them in the air.

A hollow core slab is a structural slab that supports both the upper and lower parts of the floor in the air!

By the way, you should not discount the dynamic load. It, as you might guess, is created by people themselves, as well as the things they move. All this affects the properties and states of the panel.

Diagram of a hollow core slab with holes

For example, if you once transport a heavy piano in a small two-story house from one place to another is normal, but daily movement will create much more on a multi-hollow slab Negative influence. It is unlikely to fall, but there may be serious problems with ventilation later.

Based on the type of load distribution, they are divided into 2 groups:

• distributed;
• point.

To understand the difference between these two types, it is worth giving an example. The same huge crystal chandelier, which weighs one tone - this is a point load. But a suspended ceiling with a frame over the entire surface of the slab is already a distributed load.

Construction of a technological line for the production of hollow core slabs

But there is also a combined load, combining point and distributed. For example, a bathtub filled to the top. The bathtub itself stands on legs, and its pressure on the legs is a type of distributed load. But the legs standing on the floor are already a point load.

Its cost directly depends on the weight of the hollow core slab.

It's complicated, but you can figure it out. And it is necessary! After all, the calculation for floors and hollow core slabs during construction it will still be necessary to produce.

Brands of hollow core slabs

As a matter of fact, hollow core slabs don’t even have brands as such. We are talking about markings that reflect some parameters. It is enough to give a small example.

Scheme of laying a hollow core slab on a crossbar

Let's say the panel has the following markings: PC 15-13-10 PC - means hollow core slab; all digital designations indicate any technical parameters.

15 would mean that the panel is approximately 15 decimeters (1.5 meters) long. Why approximately? It’s just that the length can be 1.498 meters, but on the marking the manufacturer has the right to round this figure to 1.5 meters (15 decimeters). The number 12 means that the product is 10 decimeters wide. The last digit (in this case 10) is the most important indicator.

This is the load that the material can withstand (maximum permissible). In our case, the maximum load will be 10 kilograms per 1 dm². Usually builders calculate the load per square meter, here it will be 1000 kilograms per 1 m². In general, everything is not so difficult.

The panel brand always looks like PC-XX-XX; if sellers offer other options, then you should be wary.

Load calculation

Calculation of limiting impact

Calculation of limiting impact - required condition when designing a building. The dimensions and other parameters of the panels are determined by the old, good Soviet GOST number 9561-91.

Construction of a hollow core slab with a reinforced screed

In order to determine the load that will be exerted on the product, it is necessary to indicate on the drawing of the future structure the weight of absolutely all elements that will “press” on the ceiling. Their total weight will be the maximum load.

First of all, you need to consider the weight of the following elements:

• cement-sand screeds;
• gypsum concrete partitions;
• weight flooring or panels;
• thermal insulation materials.

Subsequently, all the obtained indicators are summed up and divided by the number of panels that will be present in the house. From here you can get the maximum, maximum load on each specific product.

Calculation of optimal load

It is clear that the maximum permissible level is a critical indicator, which cannot be brought to under any circumstances. Therefore, it is best to calculate the optimal indicator. For example, a panel weighs 3000 kg. It is needed for an area of ​​10 m².

It is necessary to divide 3000 by 10. The result is that the maximum permissible value load will be 300 kilograms per 1 m². This is a small indicator, but you also need to take into account the weight of the product itself, for which the load was also calculated (let’s say its value is 800 kilograms per 1 m²). From 800 you need to subtract 300, the result is 500 kilograms per 1 m².

Now you need to roughly estimate how much all the loading elements and objects will weigh. Let this figure be equal to 200 kilograms per 1 m². From the previous indicator (500 kg/m²) you need to subtract the resulting one (200 kg/m²). The result will be a figure of 300 m². But that's not all.

Diagram of a hollow core slab with waterproofing

Now you need to subtract the weight of the furniture from this indicator, finishing materials, the weight of people who will constantly be indoors or in the house. “Live weight” and all elements, their load, let it be 150 kg/m². From 300 you need to subtract 150. As a result, the optimal permissible indicator will be obtained, the designation of which will be 150 kg/m². This will be the optimal load.

Advantages of hollow core slabs

Among the advantages of these products are the following:

• relatively small load on the perimeter of the entire building, in contrast to the same solid products;
• high strength indicators, despite the fact that the panels at the bottom are hollow;
• reliability;
• settlement of the house will be much less intense than when using solid products (in fact, this advantage comes from the relatively low weight);
• relatively low cost.

In general, hollow-core panels are one of the most important building materials. Today it is produced by only a few factories throughout vast Russia. The main thing, as noted above, is not to be deceived when purchasing.

Diagram of the arrangement of reinforcement blocks in a hollow-core floor slab

Sometimes (this is rare, but still) sellers try to sell low-quality panels, so-called lightweight ones. For example, they may be marked indicating that the product is designed for a load of 500 kilograms per square meter, but in reality this parameter is several times lower.

It's not even a scam, it's... criminal offense which must be punished to the fullest extent of the law. After all, if you buy a panel designed for a smaller load, there is a serious risk of building collapse. This situation can be observed not only in the provinces, but even in Moscow or St. Petersburg.

In general, you need to be extremely careful when purchasing such products. It is important to remember that any design mistake can even have tragic consequences.

Video

You can watch a video where experts talk in detail about the features of different types of hollow core slabs.

The production of floor slabs of various types and sizes is carried out in strict accordance with the requirements regulated by GOST 23009-78. The technology for producing floor slabs in accordance with GOST in this edition has been used by enterprises since 1979.

The regulatory document provides for the main quality characteristics finished products, the possibility of its use in various fields construction industry. All products manufactured in factories are marked, which contains information about the characteristics of the floor slab, its overall parameters and purpose.

Classification of finished products is carried out taking into account the following criteria:

• type of construction;
• the type of concrete used in the production;
• resistance to environmental factors;
• design features.

Possibility of using building material

Concrete floor slabs are widely used in industrial and private construction in the construction of buildings for various purposes. Their use makes it possible to obtain reliable and durable design, capable of withstanding large mechanical loads without losing its quality characteristics.

Reinforced concrete products are used in a number of works, namely:

• laying the foundation;
• construction of tunnels;
• construction of overpasses;
• creation of strapping beams;
• construction of a foundation for cranes and other heavy construction equipment;
• erection of floors in residential and commercial buildings;
• creation of parapets;
• arrangement of the bottom in channels for communications;
• construction of support cushions;
• construction flights of stairs etc.

Installation of floor slabs is impossible without the use of special equipment, which is due to the large weight and large dimensions of the products.

To install floor slabs, you need to rent a truck crane with a lifting capacity of up to 5 tons. With the help of special equipment, the installation of concrete products is carried out quickly and safely.

Rigging work

Loading, unloading and moving blocks around the construction site is carried out thanks to the presence of embedded loops on the products, designed to hook the hooks of the cables. In the event that the products do not have fasteners, it is necessary to think in advance alternative way their movements.

Usually, optimal solution is the use of special gripping devices (conductors). Ceilings not equipped with hinges have a trapezoidal cross-section, and on the side surfaces of the product there are protrusions, for which the conductor’s grips are fixed.

Storage of concrete floors

In order to maintain quality characteristics and integrity, it is necessary to comply with the rules for maintaining concrete products at the construction site. The product must be in a strictly horizontal position; immersion is strictly prohibited. reinforced concrete slabs into the ground, which leads to cracking of the ceiling. Also, the slabs cannot be stacked on top of each other; it is necessary to lay linings along the ends.

The procedure for performing installation work:

• Preparation of cement mortar.
• Installing the crane into the working position, preparing for lifting.
• Applying the solution to the supporting areas (layer – 2-3 cm).
• Transferring the product to the installation site.
• Checking the reliability of the product’s support on the supporting structure.
• Lowering the ceiling.
• Checking horizontal seams.
• Filling voids cement mortar.

When constructing structures that require large weight loads, care must be taken to improve the load-bearing capacity. To achieve this, the distance between the floor slabs must not only be filled with cement mortar, but also additionally reinforced. Along the outer perimeter of the structure it is worth equipping monolithic belt(width – at least 5 cm). Reinforcement cage must be made of two metal rods and laid vertically.

The same principle is used to strengthen the joints between the slabs located inside the ceiling. Thus, all structural elements of the floor are connected into a single monolithic block. Load-bearing capacity increases significantly: for monolithic concrete structures– by 40%, and for cellular floors– 100%.

Dimensions

On the Russian concrete products market, floor slabs are represented by a wide range. For each type of work (taking into account the expected load), manufacturers offer products of various overall dimensions. The table shows the most popular sizes of floor slabs of various brands.

Brand	Length, mm	Width, mm	Weight, t	Volume, m3
PC 17-10.08	1680	990	0,49	0,36
PC 20-10.08	1980	990	0,76	0,54
PC 30-10.08	2980	990	1,11	0,78
PC 40-10.08	3980	990	1,2	0,87
PC 51-10.08	5080	990	1,475	1,11
PC 60-10.08	5980	990	1,725	1,3
PC 70-10.08	6980	1190	2,06	1,52
PC 80-12.08	7980	1190	3,063	2,09
PC 90-12.08	8980	1190	3,2	2,38

The number “8” in the designation of the slab brand determines the optimal design load, which is 800 kgf/m2. What is the standard indicator for the construction of residential buildings.

Floor slabs - GOST

Floor slabs are used in the construction multi-storey buildings for various purposes, the quality of products is the key to safe and long-term operation of the building. The slabs are produced in strict accordance with state standards and may contain light, heavy or silicate concrete.

The production technology provides for the presence of voids in the material, which lighten the slab and provide it with increased heat and sound insulation qualities. The maximum permissible diameter of round voids is 15.9 mm. The minimum width of the slabs is 1 m, and the maximum is 1.8 m. The length of the product is up to 9.2 m.

According to GOST for floor slabs, the concrete used to create the slabs must meet class B22.5 in terms of quality parameters. The density of cement powder should be 2000-2400 kg/m3.

The strength of the product is achieved through the use of heavy-duty steel reinforcement as a frame.

The state standard regulates the grade of concrete used, taking into account its frost resistance (F200.F). According to GOST 9561-91, hollow core slabs are made from concrete, the strength of which is 261.9 kg/cm 2.

Product range

Depending on the expected loads and other operating conditions, slabs with appropriate characteristics are selected. When choosing a material, you need to pay attention to the type of reinforcement and grade of concrete. The main types of concrete used in creating products:

• L- easy;
• AND– heat-resistant;
• WITH– silicate;
• I– cellular;
• M– fine-grained.

Concrete products are also classified according to the degree of resistance to factors external environment. Based on the surface quality of the product, there are:

• N– normal permeability;
• P– reduced permeability;
• ABOUT– special permeability.

Having studied the assortment of floor slabs, you can choose the product that is optimally suitable for each individual type of work.

The presence of the designation “C” in the marking indicates resistance to seismic vibrations, the degree of which does not exceed 7 points.

Depending on the purpose, the products can be monolithic or hollow. Monolithic products have increased strength and greater weight, and products with voids are lightweight, which significantly lightens the load on the supporting structure.

Floor slabs refer to structures with load-bearing capabilities that separate floors or different temperature zones. The products are made of concrete and reinforced concrete, the second type is considered universal and is suitable for both horizontal and vertical placement. The main criteria for their selection include the type of slab, dimensions and weight, withstandable load-bearing capacity, diameter of voids, additional conditions of use. This information must be indicated by the manufacturer in the labeling; the order of arrangement of symbols is regulated by GOST 23009-2016.

Depending on the design, solid (solid) and hollow varieties are distinguished. According to the method of arrangement, they can be monolithic, prefabricated monolithic or prefabricated. Hollow-core reinforced concrete floor slabs, which combine light weight and reliability, are in maximum demand. Their technical conditions and markings are regulated by GOST 9561-91, based on the thickness, number of sides, shape and diameter of voids, 15 main types are distinguished.

Solid products, depending on their shape and functional purpose, are divided into:

1. Solid beamless panels with smooth surface, optimal for bookmarking ceilings. They are in demand in private construction, valued for their ease of finishing, their use implies a refusal suspension systems. Substantial part made from cellular concrete.

2. Ribbed - with vertical stiffening ribs that act as supports. The reliability of such floor slabs is explained by the removal of concrete from areas subject to tensile loads and an increase in its volume at compression points. The characteristics and designations of this variety are regulated by GOST 28042-89. The main scope of application is civil and residential construction; in private houses they are not economically feasible.

3. Caisson (frequently ribbed or often beamed) groups. Represent monolithic slab, laid on top of square cells of floor beams. Thus, on the one hand they have a smooth surface, on the other they resemble waffles.

These structures are designed for operation under heavy loads; they are practically not used in private construction (according to SP 52-103-2007, they are recommended when the span of one room exceeds 12-15 m).

Standard marking of floor slabs, regardless of their type, consistently includes:

• Designation of the type of design and product.
• Dimensions in numbers: length and width, height refers to standard sizes and is not indicated.
• Load-bearing capacity of floor slabs (1 unit in numerical value corresponds to withstand 100 kg/m2).
• Class of the tested fittings.
• Additional characteristics and properties, such as: resistance to aggressive environments, seismic influences, low temperatures, designation of embedded elements or holes (if any).

Explanation of symbols

Types of overlap are marked with letters; the number in front of them is indicated for hollow-core varieties and characterizes the diameter of the internal holes. Examples of possible designations and their interpretation for popular solid types are given in the table:

The marking of hollow-core panels includes a letter designation of the number of sides that support the slab (“T” corresponds to three, “K” to four). The absence of a third letter implies support for the structure on both sides. Decoding of the main types in this case:

Designation of slabs	Thickness, mm	Type of voids, features	Nominal distance between centers of voids in slabs, not less than mm	Diameter, mm
1 PC (1 may not be specified)	220	Round	185	159
2pcs				140
3pcs				127
4pcs	260	The same, with cutouts in the upper zone along the contour		159
5pcs		Round	235	180
6pcs			233	203
7pcs	160		139	114
PG	260	Pear-shaped	Assigned in accordance with the parameters of the molding equipment of the manufacturer of hollow core slabs
PB	220	Manufactured by continuous forming

The main difference between PC and PG panels and PB panels is the manufacturing method: the first two are poured into formwork structures, the latter is molded continuously (conveyor technology). As a result, floors marked PB have a smoother surface that is protected from external influences. They are less limited in length and are suitable for rooms with non-standard dimensions. The disadvantages of molding plates include narrower holes (the diameter of the voids when marking PB does not exceed 60 mm), unlike PC and PG, they cannot be drilled through for laying communications, at least this rule applies to high-rise buildings.

The length and width of each type are also limited by the standard; they are indicated in decimeters and rounded up. The actual size of reinforced concrete hollow-core slabs is usually 10-20 mm smaller. The following digital designation characterizes the design load of the slab; this indicator depends on the quality of the concrete and the reinforcement metal used. The reinforcement class is not always indicated; its mention is mandatory only for prestressed structures. If necessary, its designations are guided by the technical conditions for reinforcing steel.

The next marking point concerns the brand of concrete used (not indicated for heavy groups). Other types include: cellular (I), light (L), dense silicate (S), fine-grained (M), heat-resistant (W) and sand concrete (P) compositions. For floor slabs intended for work in conditions of exposure to aggressive environments, resistance is indicated in letter terms: normal permeability (N), reduced (P) and especially low (O). Another indicator is seismic resistance: structures designed for such loads are designated with the letter “C”. All additional features are indicated in the product labeling in Arabic numbers or letters.

Cost of slabs

Marking	Dimensions: L×W×H, cm	Weight, kg	Load-bearing capacity, kg/m2	Retail price per piece, rubles
Hollow core slabs with round holes, supported on 2 sides
PC-16.10-8	158×99×22	520	800	2940
PC-30.10-8	298×99×22	880		6000
PK-60.18-8	598×178×22	3250		13340
PK-90.15-8	898×149×22	4190		40760
Floor slabs, bench formless formation. Products are placed on 2 end sides
PB 24.12-8	238×120×22	380	800	3240
PB 30.12-12	298×120×22	470	1200	3950
PB 100.15-8	998×145×22	2290	800	29100
Ribbed ceilings without an opening in the shelf
2PG 6-3 AIV t	597×149×25	1230	500	12800
4PG 6-4 AtVt	597×149×30	1500	820	14150

GOST 9561-91 contains the requirements mandatory for the manufacture of multi-hollow reinforced concrete slabs from light, heavy, dense silicate concrete intended for covering the load-bearing part of buildings and structures for various purposes. When using slabs for their intended purpose, be sure to follow the instructions in the working drawings and additional requirements that are specified when ordering structures. GOST 9561-91 is valid from 01/01/92.

GOST 9561-91

Group Zh33

STATE STANDARD OF THE USSR UNION

REINFORCED CONCRETE MULTI-HOLLOW FLOORS PLATES FOR BUILDINGS AND STRUCTURES

TECHNICAL CONDITIONS

Reinforced concrete multihollow panels

for floors in buildings. Specifications

Date of introduction 1992-01-01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the State Committee for Architecture and Urban Planning under the USSR State Construction Committee (Goskomarchitektura) and the Central Research and Design Experimental Institute industrial buildings and structures (TsNIIpromzdany) of the USSR State Construction Committee

DEVELOPERS

L. S. Exler; A. A. Muzyko (topic leaders); I. I. Podguzova; A. A. Tuchnin, Ph.D. tech. sciences; E. N. Kodysh, Ph.D. tech. sciences; I. B. Baranova; V. G. Kramar, Ph.D. tech. sciences; G. I. Berdichevsky, Doctor of Engineering. sciences; V. L. Morozensky, Ph.D. tech. sciences; Yu. Ts. Khodosh; B.V. Karabanov, Ph.D. tech. sciences; V. V. Sedov; E. L. Shakhova; B. N. Petrov; Ya 3. Gilman; G. V. Turmanidze; N. A. Kapanadze; B.V. Kroshkov; V. I. Pimenova; V. I. Denshchikov

2. APPROVED AND ENTERED INTO EFFECT by the Resolution State Committee USSR on construction and investment dated 09.20.91 No. 5

3. INSTEAD OF GOST 9561-76 and GOST 26434-85 regarding types, main dimensions and parameters of hollow-core slabs

4. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

GOST 5781-82 GOST 6727-80 GOST 7348-81 GOST 8829-85 GOST 10060-87 GOST 10180-90 GOST 10181.0-81 GOST 10181.3-81 GOST 10884-81 GOST 10922-90 GOST 12730.0-78 GOST 12730.1-78 GOST 12730.5-84 GOST 13015.0-83 GOST 13015.1-81 GOST 13015.2-81 GOST 13015.4-84 GOST 13840-68		GOST 1762387 GOST 17624-87 GOST 17625-83 GOST 18105-86 GOST 22362-77 GOST 22690-88 GOST 22904-78 GOST 23009-78 GOST 23858-79 GOST 25214-82 GOST 25697-83 GOST 25820-83 GOST 26134-84 GOST 26433.0-85 GOST 26433.1-89 GOST 26633-85 TU 14-4-1322-89

This standard applies to reinforced concrete hollow-core slabs (hereinafter referred to as slabs), made from heavy, light and dense silicate concrete and intended for the load-bearing part of the floors of buildings and structures for various purposes.

The slabs are used in accordance with the instructions of the working drawings of the slabs and additional requirements specified when ordering these structures.

1. TECHNICAL REQUIREMENTS

1.1. Plates should be manufactured in accordance with the requirements of this standard and technological documentation approved by the manufacturer, according to working drawings standard designs(see Appendix 1) or designs of buildings (structures).

It is allowed, by agreement between the manufacturer and the consumer, to produce slabs that differ in types and sizes from those given in this standard, subject to the remaining requirements of this standard.

1.2. Main parameters and dimensions

1.2.1. Plates are divided into types:

1PK - 220 mm thick with round voids with a diameter of 159 mm, designed for support on two sides;

1PKT - the same, for support on three sides;

1PKK - the same, for support on four sides;

2PK - 220 mm thick with round voids with a diameter of 140 mm, designed for support on two sides;

2PKT - the same, for support on three sides;

2PKK - the same, for support on four sides;

3PK - 220 mm thick with round voids with a diameter of 127 mm, designed for support on two sides;

3PKT - the same, for support on three sides;

3PKK - the same, for support on four sides;

4PK - 260 mm thick with round voids with a diameter of 159 mm and cutouts in the upper zone along the contour, intended for support on both sides;

5PK - 260 mm thick with round voids with a diameter of 180 mm, designed for support on two sides;

6PK - 300 mm thick with round voids with a diameter of 203 mm, designed for support on two sides;

7PK - 160 mm thick with round voids with a diameter of 114 mm, designed for support on two sides;

PG - 260 mm thick with pear-shaped voids, designed for support on two sides;

PB - 220 mm thick, manufactured by continuous molding on long stands and designed to be supported on two sides.

1.2.2. The shape and coordination length and width of the slabs (except for PB type slabs) must correspond to those given in table. 1 and to hell. 1-3. For buildings (structures) with a calculated seismicity of 7 points or more, it is allowed to manufacture slabs having a shape different from that indicated in the drawing. 1-3.

1.2.3. The structural length and width of the slabs (except for PB type slabs) should be taken equal to the corresponding coordination size (Table 1), reduced by the value a(1) (the gap between adjacent slabs) or a(2) (the distance between adjacent slabs if there is between them of a separating element, for example, an anti-seismic belt, ventilation ducts, crossbar ribs), or increased by the value a(3) (for example, for slabs supported on the entire thickness of the walls staircase buildings with transverse load-bearing walls). The values ​​of a(1), a(2) and a(3) are given in table. 2.

1.2.4. The shape and dimensions of PB type slabs must correspond to those established in the working drawings of the slabs, developed in accordance with the parameters of the molding equipment of the manufacturer of these slabs.

Table 1

	Drawing number	Coordination dimensions of the slab, mm
		From 2400 to 6600 inclusive. at intervals of 300, 7200, 7500	1000, 1200, 1500, 1800, 2400, 3000, 3600
			1000, 1200, 1500
		From 3600 to 6600 inclusive. at intervals of 300, 7200, 7500
		From 2400 to 3600 inclusive. at intervals of 300	From 4800 to 6600 inclusive. at intervals of 300, 7200
		From 2400 to 6600 inclusive. at intervals of 300, 7200, 9000	1000, 1200, 1500
		6000, 9000, 12000	1000, 1200, 1500
			1000, 1200, 1500
		From 3600 to 6300 inclusive. at intervals of 300	1000, 1200, 1500, 1800
		6000, 9000, 12000	1000, 1200, 1500

Note. The length of the slabs is taken to be:

size of the side of the slab not supported by bearing structures buildings (structures) - for slabs intended to be supported on two or three sides;

the smaller size of the slab in plan - for slabs intended to be supported along the contour.

Plates types 1PK, 2PK, 3PK, 5PK, 6PK, 7PK

Plates types 1PKT, 2PKT, 3PKT

Plates of types 1PKK, 2PKK, 3PKK

Plate type 4pcs

Plate type PG

Notes to hell. 1-3

1. Slabs of types 1PKT, 2PKT, 3PKT, 1PKK, 2PKK and 3PKK can have technological bevels along all side faces.

2. Methods for strengthening the ends of the slabs are shown in Fig. 1-3 as an example. It is permissible to use other methods of reinforcement, including reducing the diameter of the voids through one on both supports without sealing the opposite ends of the voids.

3. The dimensions and shape of the groove along the longitudinal upper edge of slabs of types 1PKT, 2PKT and 3PKT (Drawing 1b) and along the contour of slabs of type 4PK (Drawing 2) are established in the working drawings of the slabs.

4. In slabs intended for buildings (structures) with a design seismicity of 7-9 points, extreme voids may be absent due to the need to install embedded products or releases of reinforcement for connections between slabs, walls, and anti-seismic belts.

table 2

Scope of application of plates	Additional dimensions taken into account when determining the structural size of the slab, mm
				width a(1)
Large-panel buildings, including buildings with a calculated seismicity of 7-9 points				10 - for slabs with a coordination width of less than 2400. 20 - for slabs with a coordination width of 2400 or more
Buildings (structures) with walls made of bricks, stones and blocks, with the exception of buildings (structures) with a calculated seismicity of 7-9 points
Buildings (structures) with walls made of bricks, stones and blocks with a calculated seismicity of 7-9 points
Frame buildings (structures), including buildings (structures) with a calculated seismicity of 7-9 points

1.2.5. Voids in slabs intended to be supported on two or three sides should be located parallel to the direction along which the length of the slabs is determined. In slabs intended to be supported on four sides, the voids should be located parallel to any side of the slab contour.

The nominal distance between the centers of voids in slabs (except for slabs of types PG and PB) should be taken as no less than, mm:

185 - in slabs of types 1PK, 1PKT, 1PKK, 2PK, 2PKT, 2PKK, 3PK, 3PKT, 3PKK and 4PK;

235 - in slabs of type 5PK;

233 " " " 6pcs;

139 « « « 7pcs.

The distance between the centers of the voids of slabs of types PG and PB is determined in accordance with the parameters of the molding equipment of the manufacturer of these slabs.

1.2.6. The slabs should be made with recesses or grooves on the side faces to form, after embedding, intermittent or continuous keys that ensure the joint operation of the floor slabs for shear in the horizontal and vertical directions.

By agreement between the manufacturer and the consumer and the design organization - the author of the project for a specific building (structure), it is allowed to produce slabs without recesses or grooves for the formation of keys.

1.2.7. Slabs intended to be supported on two or three sides should be made prestressed. Slabs with a thickness of 220 mm, a length of less than 4780 mm, with voids with diameters of 159 and 140 mm and slabs with a thickness of 260 mm, with a length of less than 5680 mm, as well as slabs with a thickness of 220 mm, of any length, with voids with a diameter of 127 mm may be manufactured with non-prestressing reinforcement.

1.2.8. The slabs should be made with reinforced ends. Strengthening the ends is achieved by reducing the cross-section of the voids on the supports or filling the voids with concrete or concrete liners (Fig. 1-3). When the design load on the ends of the slabs in the wall support zone does not exceed 1.67 MPa (17 kgf/sq.cm), it is allowed, by agreement between the manufacturer and the consumer, to supply slabs with unreinforced ends.

Reinforcement methods and minimum dimensions of embedments are established in working drawings or indicated when ordering slabs.

1.2.9. In cases provided for by the working drawings of a particular building (structure), slabs may have embedded products, reinforcement outlets, local cutouts, holes and other additional structural details.

1.2.10. To lift and install slabs, mounting loops or special gripping devices are used, the design of which is established by the manufacturer in agreement with the consumer and the design organization - the author of the building (structure) project. The location and dimensions of holes in slabs intended for loopless installation are taken according to the drawings included in the package. project documentation gripping device for these slabs.

1.2.11. The consumption of concrete and steel on the slabs must correspond to those indicated in the working drawings of these slabs, taking into account possible clarifications made by the design organization in the prescribed manner.

1.2.12. The slabs are used taking into account their fire resistance limit specified in the working drawings of the slabs.

1.2.13. The slabs are designated by marks in accordance with the requirements of GOST 23009. The slab mark consists of alphanumeric groups separated by hyphens.

In the first group, indicate the designation of the type of slab, the length and width of the slab in decimeters, the values ​​of which are rounded to the nearest whole number.

In the second group indicate:

the calculated load on the slab in kilopascals (kilogram-force per square meter) or the serial number of the slab in terms of bearing capacity;

steel class of prestressed reinforcement (for prestressed slabs);

type of concrete (L - lightweight concrete, C - dense silicate concrete; heavy concrete is not indicated).

In the third group, if necessary, indicate additional characteristics reflecting special conditions application of slabs (for example, their resistance to aggressive gaseous media, seismic influences), as well as designations design features slabs (for example, the presence of additional embedded products).

An example of a symbol (brand) of a 1PK type slab with a length of 6280 mm, a width of 1490 mm, designed for a design load of 6 kPa, made of lightweight concrete with prestressed reinforcement class At-V:

1PK63.15-6AtVL

The same, made of heavy concrete and intended for use in buildings with a calculated seismicity of 7 points:

1PK63.15-6AtV-S7

Note. It is allowed to accept the designation of slab brands in accordance with the working drawings of the slabs until they are revised.

1.3 Characteristics

1.3.1. The slabs must meet the requirements established during the design for strength, rigidity, crack resistance, and when tested by loading in the cases provided for in the working drawings, withstand control loads.

1.3.2. The slabs must meet the requirements of GOST 13015.0:

according to the actual strength of concrete (at design age, transfer and tempering);

on the frost resistance of concrete, and for slabs operated under conditions of exposure to an aggressive gaseous environment - also on the water resistance of concrete;

By medium density lightweight concrete;

to steel grades for reinforcing and embedded products, including mounting loops;

by deviations in the thickness of the protective layer of concrete to the reinforcement;

for corrosion protection.

Slabs used as the load-bearing part of loggias must also meet the additional requirements of GOST 25697.

1.3.3. Slabs should be made of heavy concrete in accordance with GOST 26633, structural lightweight concrete of a dense structure with an average density of at least 1400 kg/cub.m in accordance with GOST 25820 or dense silicate concrete with an average density of at least 1800 kg/cub.m in accordance with GOST 25214 strength classes or grades for compression specified in the working drawings of these slabs.

1.3.4. Compression forces (releasing the tension of the reinforcement) are transferred to the concrete after it reaches the required transfer strength.

The normalized transfer strength of concrete of prestressed slabs, depending on the class or grade of concrete in terms of compressive strength, the type and class of prestressing reinforcing steel, must correspond to that indicated in the working drawings of these slabs.

1.3.5. The normalized tempering strength of concrete for prestressed slabs made of heavy or light concrete for the warm season should be equal to the normalized transfer strength of concrete, and for slabs with non-prestressed reinforcement - 70% of the compressive strength of concrete corresponding to its class or grade. When delivering these slabs in the cold season or to ensure their safety during transportation by rail in the warm season (by agreement between the manufacturer and consumer of the slabs), the normalized tempering strength of concrete can be increased to 85% of the compressive strength of concrete corresponding to its class or grade .

The normalized tempering strength of concrete for slabs made of dense silicate concrete should be equal to 100% of the compressive strength of concrete corresponding to its class or grade.

1.3.6. Reinforcing steel should be used to reinforce slabs the following types and classes:

as prestressed reinforcement - thermomechanically strengthened rod of classes At-IV, At-V and At-VI according to GOST 10884 (regardless of weldability and increased resistance to corrosion cracking of the reinforcement), hot-rolled rod of classes A-IV, A-V and A-VI according to GOST 5781, reinforcing ropes of class K-7 according to GOST 13840, high-strength periodic wire of class VR-II according to GOST 7348, wire of class VR-600 according to TU 14-4-1322 and rod reinforcement class A-I IIv, made of reinforcing steel of class A-III according to GOST 5781, strengthened by drawing with control of the stress value and ultimate elongation;

as non-stressed reinforcement - hot-rolled rod of periodic profile of classes A-II, A-III and smooth class A-I according to GOST 5781, periodic wire of class BP-I according to GOST 6727 and class BP-600 according to TU 14-4-1322.

In slabs produced by methods of continuous formless molding on long stands, continuous reinforcement, as well as using multi-temperature electrothermal tension, high-strength wire reinforcement is used in accordance with GOST 7348 and ropes in accordance with GOST 13840.

1.3.7. The shape and dimensions of reinforcement and embedded products and their position in the slabs must correspond to those indicated in the working drawings of these slabs.

1.3.8. Welded reinforcement and embedded products must comply with the requirements of GOST 10922.

1.3.9. The stress values ​​in the prestressing reinforcement, monitored after tensioning it on the stops, must correspond to those indicated in the working drawings of the slabs.

The values ​​of actual stress deviations in prestressed reinforcement should not exceed the limits specified in the working drawings of the slabs.

1.3.10. The values ​​of actual deviations of the geometric parameters of the slabs should not exceed the limits indicated in the table. 3.

Table 3

Name of deviation of geometric parameter	Name geometric parameter
Deviation from linear size	Slab length and width: up to 2500 incl. St. 2500 to 4000 incl. St. 4000 to 8000 incl. Slab thickness Position size: holes and cutouts embedded products: in the plane of the slab from the plane of the slab
Deviation from straightness of the profile of the upper surface of the slab, intended for direct gluing of linoleum, as well as the profile of the side faces of the slab at a length of 2000
Deviation from the flatness of the front lower (ceiling) surface of the slab when measured from a conventional plane passing through three corner points of the slab with a length of:

* The deviation from the size that determines the position of the embedded product from the upper plane of the slabs intended for direct gluing of linoleum should only be inside the slab.

1.3.11. Requirements for the quality of concrete surfaces and appearance slabs (including requirements for the permissible opening width of technological cracks) - according to GOST 13015.0 and this standard.

1.3.12. The quality of concrete slab surfaces must meet the requirements established for the categories:

A3 - lower (ceiling);

A7 - top and side.

By agreement between the manufacturer and the consumer, the following categories of surfaces can be installed instead of the indicated ones:

A2 - lower (ceiling), prepared for painting;

A4 - the same, prepared for wallpapering or decorative finishing paste-like compositions, and the top, prepared for covering with linoleum;

A6 - lower (ceiling), for which there are no requirements for the quality of finishing.

1.3.13. In the concrete of slabs supplied to the consumer, cracks are not allowed, with the exception of shrinkage and other surface technological cracks with a width of no more than 0.3 mm on the top surface of the slabs and no more than 0.2 mm on the side and bottom surfaces of the slabs.

1.3.14. Exposure of reinforcement is not allowed, with the exception of reinforcement outlets or ends of prestressing reinforcement, which should not protrude beyond the end surfaces of the slabs by more than 10 mm and should be protected with a layer cement-sand mortar or bitumen varnish.

1.4. Marking

Marking of slabs is in accordance with GOST 13015.2. Markings and signs should be applied to side faces or the top surface of the slab.

On the upper surface of a slab supported on three sides, signs “Location of support” should be placed in accordance with GOST 13015.2, located in the middle at each side of the slab support.

2. ACCEPTANCE

2.1. Acceptance of slabs is in accordance with GOST 13015.1 and this standard. In this case, the slabs are accepted based on the results:

periodic testing - in terms of strength, rigidity and crack resistance of slabs, frost resistance of concrete, porosity (volume of intergranular voids) of a compacted mixture of lightweight concrete, as well as water resistance of concrete slabs intended for use in conditions of exposure to an aggressive environment;

acceptance tests - in terms of concrete strength (class or grade of concrete in terms of compressive strength, transfer and tempering strengths), average density of light or dense silicate concrete, compliance of reinforcement and embedded products with working drawings, strength of welded joints, accuracy of geometric parameters, thickness of the protective layer concrete to reinforcement, technological crack opening width and category concrete surface.

2.2. Periodic testing loading of slabs to control their strength, rigidity and crack resistance is carried out before the start of their mass production and subsequently - when adding constructive changes and when manufacturing technology changes, as well as in the process of serial production of slabs, at least once a year. Load testing of slabs in the event of structural changes being made to them and when manufacturing technology is changed, depending on the essence of these changes, may not be carried out in agreement with the design organization that developed the working drawings of the slabs.

Testing of slabs with a length of 5980 mm or less during their serial production may not be carried out if non-destructive testing is carried out in accordance with the requirements of GOST 13015.1.

2.3. Slabs in terms of the accuracy of geometric parameters, the thickness of the protective layer of concrete before the reinforcement, the width of the opening of technological cracks and the category of the concrete surface should be accepted based on the results of random inspection.

2.4. The porosity (volume of intergranular voids) of a compacted mixture of lightweight concrete should be determined at least once a month.

2.5. The document on the quality of slabs intended for use in conditions of exposure to aggressive environments must additionally indicate the grade of concrete for water resistance (if this indicator is specified in the order for the production of slabs).

3. CONTROL METHODS

3.1. Load tests of slabs to control their strength, rigidity and crack resistance should be carried out in accordance with the requirements of GOST 8829 and working drawings of these slabs.

3.2. The strength of concrete slabs should be determined according to GOST 10180 on a series of samples made from concrete mixture working personnel and stored under the conditions established by GOST 18105.

When determining the strength of concrete using non-destructive testing methods, the actual transfer and tempering compressive strength of concrete is determined by the ultrasonic method in accordance with GOST 17624 or mechanical devices in accordance with GOST 22690. It is permissible to use other non-destructive testing methods provided for by the standards for concrete testing methods.

3.3. The frost resistance of concrete slabs should be determined according to GOST 10060 or by the ultrasonic method according to GOST 26134 on a series of samples made from a concrete mixture of the working composition.

3.4. The water resistance of concrete slabs intended for operation in conditions of exposure to aggressive environments should be determined according to GOST 12730.0 and GOST 12730.5.

3.5. The average density of light and dense silicate concrete should be determined according to GOST 12730.0 and GOST 12730.1 or by the radioisotope method according to GOST 17623.

3.6. The porosity indicators of a compacted mixture of lightweight concrete should be determined according to GOST 10181.0 and GOST 10181.3.

3.7. Inspection of welded reinforcement and embedded products - in accordance with GOST 10922 and GOST 23858.

3.8. The tension force of the reinforcement, controlled at the end of the tension, is measured according to GOST 22362.

3.9. The dimensions of the slabs, deviations from the straightness and flatness of the surfaces of the slabs, the width of the opening of technological cracks, the sizes of cavities, sagging and edges of concrete slabs should be determined by the methods established by GOST 26433.0 and GOST 26433.1.

3.10. The dimensions and position of reinforcement and embedded products, as well as the thickness of the protective layer of concrete up to the reinforcement should be determined according to GOST 17625 and GOST 22904. In the absence necessary devices It is allowed to cut down grooves and expose the slab reinforcement with subsequent sealing of the grooves. Furrows should be punched at a distance from the ends not exceeding 0.25 times the length of the slab.

4 TRANSPORTATION AND STORAGE

4.1. Transportation and storage of slabs - in accordance with GOST 13015.4 and this standard.

4.2. The slabs should be transported and stored in stacks laid in a horizontal position.

On specialized vehicles Transportation of slabs in an inclined or vertical position is allowed.

4.3. The height of the stack of slabs should not be more than 2.5 m.

4.4. Pads for the bottom row of slabs and spacers between them in a stack should be located near the mounting loops.

ANNEX 1

LIST OF SIZES AND SERIES

WORKING DRAWINGS OF PLATES FOR MASSIVE APPLICATION

Table 4

	Designation of a series of working drawings of slabs
	1.241-1; 1.090.1-1; 1.090.1-2s; 1.090.1-3pv;
	1.141-18s; 1.141.1-25s;
	1.241-1; 1.090.1-1
	1.141-1; 1.141.1-33s
	1.141-1; 1.141.1-30;
	1.141-1; 1.141.1-33s
	1.141-18s; 1.141.1-25s;
	1.141-1; 1.141.1-33s
	1.141-1; 1.141.1-33с; 1.090.1-2s; 1.090.1-3pv;
	1.141-1; 1.141.1-33s
	1.141-18s; 1.141.1-25s;
	1.141-1; 1.141.1-33s
	1.141-1; 1.141.1-33s
	1.141-1; 1.141.1-33с;
	1.141-1; 1.141.1-33s
	1.141-1; 1.141.1-33s
	1.141.1; 1.141.1-33с;
	1.141-1; 1.141.1-33s
	1.141-18s; 1.141.1-25s;
	1,141-1; 1.090.1-1; 1.090.1-2s; 1.090.1-3pv;
	1.141.1-28с; 1.141.1-29с
	1.141-1; 1.090.1-1; 1.090.1-2s; 1.090.1-3pv;
	1.141.1-28с; 1.141.1-29с
	141; E-600; E-600IV; E600II TsNIIEP housing
	135 KB on reinforced concrete named after. A. A. Yakusheva
	86-3191/1 TsNIIEP of commercial and household buildings and tourist complexes
	86-3191/1 TsNIIEP of commercial and household buildings and tourist complexes
	86-3191/1 TsNIIEP of commercial and household buildings and tourist complexes
	28-87 TsNIIpromzdany

APPENDIX 2

AREA OF APPLICATION OF VARIOUS TYPES OF PLATES

Table 5

Slab type	Reduced slab thickness, m	Average density of concrete slab, kg/cub.m	Slab length, m	Characteristics of buildings (structures)
			Up to 7.2 incl.	Residential buildings in which the required sound insulation of residential premises is ensured by the installation of hollow-core, floating, hollow-core layered floors, as well as single-layer floors on a leveling screed
			Up to 9.0 incl.
			Up to 7.2 incl.	Residential buildings in which the required sound insulation of residential premises is ensured by installing single-layer floors
			Up to 6.3 incl.	Residential large-panel buildings of the 135 series, in which the required sound insulation of the premises is ensured by installing single-layer floors
			Up to 9.0 incl.	Public and industrial buildings(structures)
			Up to 7.2 incl.	Low-rise and estate-type residential buildings

APPENDIX 3

Information

TERMS USED IN APPENDIX 2 AND THEIR EXPLANATIONS

Table 6

	Explanation
Single layer floor	A floor consisting of a covering (linoleum on a heat- and sound-insulating basis) laid directly on the floor slabs or on a leveling screed
Single-layer floor on a leveling screed	A floor consisting of a covering (linoleum on a heat- and sound-insulating basis) laid on a leveling screed
Hollow floor	Floor consisting of hard surface along joists and soundproofing pads laid on floor slabs
Voidless layered floor	A floor consisting of a hard surface and a thin soundproofing layer, laid directly on the floor slabs or on a leveling screed
Floating floor	A floor consisting of a covering, a rigid base in the form of a monolithic or prefabricated screed and a continuous soundproofing layer of elastic-soft or bulk materials laid on floor slabs

The text of the document is verified according to:

official publication

Gosstroy USSR - M: Standards Publishing House, 1992

This standard applies to reinforced concrete hollow-core slabs (hereinafter referred to as slabs), made from heavy, light and dense silicate concrete and intended for the load-bearing part of the floors of buildings and structures for various purposes.

The slabs are used in accordance with the instructions of the working drawings of the slabs and additional requirements specified when ordering these structures.

It is allowed, by agreement between the manufacturer and the consumer, to produce slabs that differ in types and sizes from those given in this standard, subject to the remaining requirements of this standard.

Plates are divided into types:

1pc - 220 mm thick with round voids with a diameter of 159 mm. designed to be supported on two sides;

1PKT - the same, for support on three sides;

1PKK - the same, for support on four sides;

2PK - 220 mm thick with round voids with a diameter of 140 mm, designed for support on two sides;

2PKT - the same, for support on three sides;

2PKK - the same for support on four sides;

3PK - 220 mm thick with round voids with a diameter of 127 mm, designed for support on two sides;

3PKT - the same, for support on three sides;

3PKK - the same, for support on four sides;

4PK - 260 mm thick with round voids with a diameter of 159 mm and cutouts in the upper zone along the contour, intended for support on both sides;

5PK - 260 mm thick with round voids with a diameter of 180 mm, designed for support on two sides;

6PK - 300 mm thick with round voids with a diameter of 203 mm, designed for support on two sides;

7PK - 160 mm thick with round voids with a diameter of 114 mm, designed for support on two sides;

PG - 260 mm thick with pear-shaped voids, designed for support on two sides;

PB - 220 mm thick, manufactured by continuous molding on long stands and designed to be supported on two sides.

Table 19

Slab type	Reduced slab thickness, m	Average density of concrete slab, kg/m 3	Slab length, m	Characteristics of buildings (structures)
			Up to 7.2 incl.	Residential buildings in which the required sound insulation of residential premises is ensured by the installation of hollow-core, floating, hollow-core layered floors, as well as single-layer floors on a leveling screed
			Up to 9.0 incl.
			Up to 7.2 incl.	Residential buildings in which the required sound insulation of residential premises is ensured by installing single-layer floors
			Up to 6.3 incl.	Residential large-panel buildings of the 135 series, in which the required sound insulation of the premises is ensured by installing single-layer floors
			Up to 9.0 incl.	Public and industrial buildings (structures)
			Up to 12.0 incl.
			Up to 7.2 incl.	Low-rise and estate-type residential buildings

Explanations for the table. 19

Term	Explanation
Single layer floor	A floor consisting of a covering (linoleum on a heat- and sound-insulating basis) laid directly on the floor slabs or on a leveling screed
Single-layer floor on a leveling screed	A floor consisting of a covering (linoleum on a heat- and sound-insulating basis) laid on a leveling screed
Hollow floor	A floor consisting of a hard covering along joists and soundproofing pads laid on floor slabs
Voidless layered floor	A floor consisting of a hard surface and a thin soundproofing layer, laid directly on the floor slabs or on a leveling screed
Floating floor	A floor consisting of a covering, a rigid base in the form of a monolithic or prefabricated screed and a continuous soundproofing layer of elastic-soft or bulk materials laid on floor slabs

The shape and coordination length and width of the slabs (except for PB type slabs) must correspond to those given in table. 20 and to hell. 9-11. For buildings (structures) with a calculated seismicity of 7 points or more, it is allowed to manufacture slabs having a shape different from that indicated in the drawing. 9-11.

The structural length and width of the slabs (except for PB type slabs) should be taken equal to the corresponding coordination size (Table 20), reduced by the value a1 (the gap between adjacent slabs) or a2 (the distance between adjacent slabs if there is a separating element between them, for example, antiseismic belts, ventilation ducts, crossbar ribs), or increased by the value of a3 (for example, for slabs supported by the entire thickness of the staircase walls of buildings with transverse load-bearing walls). The values ​​of a1, a2 and a3 are given in table. 21.

The shape and dimensions of PB type slabs must correspond to those established in the working drawings of the slabs, developed in accordance with the parameters of the molding equipment of the manufacturer of these slabs.

Table 20

slabs	Plate drawing number	Coordination dimensions of the slab, mm
		Length	Width
		From 2400 to 6600 inclusive. at intervals of 300, 7200, 7500	1000, 1200, 1500, 1800, 2400, 3000, 3600
			1000, 1200, 1500
		From 3600 to 6600 inclusive. at intervals of 300, 7200, 7500	From 2400 to 3600 inclusive. at intervals of 300
		From 2400 to 3600 inclusive. at intervals of 300	From 4800 to 6600 inclusive. at intervals of 300, 7200
		From 2400 to 6600 inclusive. at intervals of 300, 7200, 9000	1000, 1200, 1500
		6000, 9000, 12000	1000, 1200, 1500
			1000, 1200, 1500
		From 3600 to 6300 inclusive. at intervals of 3000	1000, 1200, 1500, 1800
		6000, 9000, 12000	1000, 1200, 1500

Note. The length of the slabs is taken to be:

the size of the side of the slab not supported by the load-bearing structures of the building (structure) - for slabs intended to be supported on two or three sides;

the smaller size of the slab in plan - for slabs intended to be supported along the contour.

Plates of types 1PKT, 2PKT, 3PKT, 5PK, 6PK, 7PKT slabs of types 1PKT, 2PKT, 3PKT

1 – 1 1 – 1

P
casts of types 1PKK, 2PKK, 3PKK

2
–2

Crap. 10. 4pc type plate

1
–1 2–2

Crap. 11. Plate type PG

1 –1 2–2

Notes to hell 9-11

1. Slabs of types 1PKT, 2PKT, 3PKT, 1PKK, 2PKK and 3PKK can have technological bevels along all side faces.

2. Methods for strengthening the ends of the slabs are shown in Fig. 9-11 as an example. It is allowed to use other methods of reinforcement, including reducing the diameter of the voids through one on both supports without sealing the opposite ends of the voids.

3. The dimensions and shape of the groove along the longitudinal upper edge of slabs of types 1PKT, 2PKT and 3PKT (Drawing 9b) and along the contour of slabs of type 4PK (Drawing 10) are established in the working drawings of the slabs.

4. In slabs intended for buildings (structures) with a design seismicity of 7-9 points, extreme voids may be absent due to the need to install embedded products or produce reinforcement for connections between slabs, walls, and anti-seismic belts.

Table 21

Scope of application of plates	Additional dimensions taken into account when determining the structural size of the slab, mm
	length			widthA 1
	A 1	A 2	A 3
Large-panel buildings, including buildings with a calculated seismicity of 7-9 points Buildings (structures) with walls made of bricks, stones and blocks, with the exception of buildings (structures) with a calculated seismicity of 7-9 points Buildings (structures) with walls made of bricks, stones and blocks with a calculated seismicity of 7-9 points Frame buildings (structures), including buildings (structures) with a calculated seismicity of 7-9 points				10 - for slabs with a coordination width of less than 2400. 20 - for slabs with a coordination width of 2400 or more

Voids in slabs intended to be supported on two or three sides should be located parallel to the direction along which the length of the slabs is determined. In slabs intended to be supported on four sides, the voids should be located parallel to any side of the slab contour.

The nominal distance between the centers of voids in slabs (except for slabs of types PG and PB) should be taken as no less than, mm:

185-in slabs of types 1PK, 1PKT, 1PKK, 2PK, 2PKT, 2PKK, 3PK, 3PKT, 3PKK and 4PK;

235 in slabs of type 5PK;

233 " " " 6pcs;

139 « « « 7pcs.

The distance between the centers of the voids of slabs of types PG and PB is determined in accordance with the parameters of the molding equipment of the manufacturer of these slabs.

The slabs should be made with recesses or grooves on the side faces to form, after embedding, intermittent or continuous keys that ensure the joint operation of the floor slabs for shear in the horizontal and vertical directions.

By agreement between the manufacturer and the consumer and the design organization - the author of the project for a specific building (structure), it is allowed to produce slabs without recesses or grooves for the formation of keys.

The slabs should be made with reinforced ends. Strengthening the ends is achieved by reducing the cross-section of the voids on the supports or filling the voids with concrete or concrete liners (Fig. 9-11). When the design load on the ends of the slabs in the wall support zone does not exceed 1.67 MPa (17 kgf/cm2), it is allowed according to upon agreement between the manufacturer and the consumer, supply slabs with unreinforced ends.

Reinforcement methods and minimum dimensions of embedments are established in working drawings or indicated when ordering slabs.

The slabs are designated by marks in accordance with the requirements of GOST 23009. The slab mark consists of alphanumeric groups separated by hyphens.

In the first group, indicate the designation of the type of slab, the length and width of the slab in decimeters, the values ​​of which are rounded to the nearest whole number.

In the second group indicate:

the calculated load on the slab in kilopascals (kilogram-force per square meter) or the serial number of the slab in terms of bearing capacity;

steel class of prestressed reinforcement (for prestressed slabs);

type of concrete ( L - lightweight concrete, C-dense silicate concrete; heavy concrete is not indicated).

In the third group, if necessary, additional characteristics are indicated that reflect the special conditions of use of the slabs (for example, their resistance to aggressive gaseous media, seismic influences), as well as designations of the design features of the slabs (for example, the presence of additional embedded products).

An example of a symbol (brand) of a 1PK type slab with a length of 6280 mm, a width of 1490 mm, designed for a design load of 6 kPa, made of lightweight concrete with prestressed reinforcement of class At-V:

1PK63.15-6A T VL

The same, made of heavy concrete and intended for use in buildings with a calculated seismicity of 7 points:

1PK63.15-6A T V-C7

Slabs should be made of heavy concrete in accordance with GOST 26633, structural lightweight concrete of a dense structure with an average density of at least 1400 kg/m 3 in accordance with GOST 25820, or dense silicate concrete with an average density of at least 1800 kg/m 3 in accordance with GOST 25214 classes or grades of compressive strength specified in the working conditions drawings of these plates.