INTERSTATE COUNCIL FOR STANDARDIZATION. METROLOGY AND CERTIFICATION

INTERSTATE COUNCIL FOR STANDARDIZATION, METROLOGY AND CERTIFICATION

INTERSTATE

STANDARD

REINFORCED CONCRETE FLOORS

FOR RESIDENTIAL BUILDINGS

Types and main parameters

Official publication

Standardinform

Preface

The goals, basic principles and basic procedure for carrying out work on interstate standardization are established by GOST 1.0-92 “Interstate standardization system. Basic provisions" and GOST 1.2-2009 "Interstate standardization system. Interstate standards, rules and recommendations for interstate standardization. Rules for development, adoption, application, updating and cancellation"

Standard information

1 DEVELOPED Joint stock company"TsNIIEP housing - institute for integrated design of residential and public buildings"(JSC "TSNIIEP Dwellings")

2 INTRODUCED by the Technical Committee for Standardization TC 465 “Construction”

3 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (protocol dated November 12, 2015 No. 82-P)

4 By order Federal agency on technical regulation and metrology dated November 30, 2015 No. 2077-st interstate standard GOST 26434-2015 entered into force as a national standard Russian Federation from January 1, 2017

5 IN REPLACEMENT 26434-65

Information about changes to this standard is published in the annual information index “National Standards”. and the text of changes and amendments is in the monthly information index “National Standards”. In case of revision (replacement) or cancellation of this standard, the corresponding notice will be published in the monthly information index “National Standards”. Relevant information, notices and texts are also posted in information system for general use - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

In the Russian Federation, this standard cannot be fully or partially reproduced, replicated and distributed as an official publication without permission from the Federal Agency for Technical Regulation and Metrology

INTERSTATE STANDARD

REINFORCED CONCRETE FLOORS FOR RESIDENTIAL BUILDINGS Types and main parameters

Reinforced concrete panels for floors in residential buftdings. Types and basic parameters

Date of introduction - 2017-01-01

1 Application area

This standard establishes the types, main dimensions and parameters of floor slabs, general technical requirements to them.

This standard applies to prefabricated reinforced concrete floor slabs made from structural heavy and lightweight concrete (hereinafter referred to as slabs) and intended for the load-bearing part of the floors of residential buildings.

The requirements of this standard should be taken into account when developing regulatory documents and working documentation for specific types of slabs.

2 Normative references

8 of this standard uses regulatory references to the following interstate standards:

GOST 13015-2012 Concrete and reinforced concrete products for construction. General technical requirements. Rules for acceptance, labeling, transportation and storage

GOST 21779-82 System for ensuring the accuracy of geometric parameters in construction. Technological tolerances

GOST 23009*78 Prefabricated concrete and reinforced concrete structures and products. Symbols (brands)

GOST 26433.0*85 System for ensuring the accuracy of geometric parameters in construction. Rules for performing measurements. General provisions

Note - When using this standard, it is advisable to check the validity of the reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or using the annual information index “National Standards”, which was published as of January 1 of the current year, and on issues of the monthly information index “National Standards” for the current year. If the reference standard is replaced (changed), then when using this standard you should be guided by the replacing (changed) standard. If the reference standard is canceled without replacement, then the provision in which a reference is made to it is applied in the part that does not affect this reference.

3 Terms and definitions

8 of this standard the following terms with corresponding definitions are used:

3.1 plate: Large-sized flat element building structure, performing load-bearing, enclosing or combined - load-bearing and enclosing, heat-technical, sound-proofing functions.

3.2 floor: Horizontal internal load-bearing structure in a building separating floors.

3.3 coordination (nominal) size of the slab: Design size of the slab between the alignment (coordination) axes of the building in the horizontal direction.

3.4 design size of the slab: Design size of the slab, differing from the design (nominal) size by a standardized gap, taking into account installation and manufacturing tolerances.

Official publication

4 Types, main parameters and dimensions

4.1 Plates are divided into the following types:

Solid single layer:

1P - slabs 120 mm thick.

2P - slabs 160 mm thick;

Multi-hollow:

1 PC - slabs 220 mm thick with round voids with a diameter of 159 mm.

2PK - slabs 220 mm thick with round voids with a diameter of 140 mm.

PB - slabs 220 mm thick without formwork.

Plates of types 2P and 2PK are made only from heavy concrete.

The shape and dimensions of voids in PB type slabs are established by standards or technical specifications for slabs of this type.

4.2 Plates of types 1P. 2P and. subject to bench molding. 1pk, 2pk can be provided for support on two or three sides or along the contour. PB type slabs are designed for support on two sides.

4.3 In residential buildings with built-in or attached public premises, for the floors of these premises it is allowed to use slabs of the types and sizes established for the floors of public buildings.

4.4 The coordination length and width of the slabs must correspond to those indicated in Table 1.

Table 1

Slab size	Coordination dimensions of the slab, mm	Slab weight (reference), t
Slab size		Slab weight (reference), t
	Plates type 1P








Plates type 2P














	Slab types

Continuation of Table 1

Slab size	Cooodinary	slab weight, mm	Slab weight (reference), t
Slab size			Slab weight (reference), t

End of table 1

Slab size	Cooodinary	plate dimensions, mm	Slab weight (reference), t
Slab size			Slab weight (reference), t

Notes

1 For slabs of type 2PK and PB in the designation of the standard size given in this table, replace 1PK with 2PK or PB.

2 If there are slabs of the same standard size that differ in reinforcement in order to be supported on two, three sides or along the contour, an additional designation should be entered into the marking.

3 Coordination length - 9000 mm is applicable only for slabs of type 1 PC.

4 The mass of the slabs is given for slabs made of heavy concrete with an average density of 2500 kg/m 1.

5 The direction of the design span of type 1PK slabs is set parallel to the length or width of the slab.

4.5 Slabs in the floor of a building should be placed in such a way that their coordination length is equal to the corresponding transverse or longitudinal pitch load-bearing structures building shown in Figure 1.

8 cases when in internal load-bearing walls with a thickness of 300 mm or more, paired coordination axes are used (replaceable in project documentation one alignment axis), the coordination length of the slab should be equal to the distance between the alignment axes of the building minus the coordination size of the insert or half the coordination size of the insert indicated in Figure 2.

to = L 0 h s In

A>. coordination length of the slab; And. the distance between the transverse and longitudinal coordination axes of the building, respectively

Figure 1

1 - coordination axes of the building; 2 - center axis of the building; a - distance between paired

coordination axes; A) - coordination length of the slab; Ai and - the distance between the transverse and longitudinal coordination axes of the building, respectively; L" and B" - the distance between the transverse and longitudinal alignment axes of the building, respectively

Figure 2

4.6 The structural length and width of the slabs should be taken equal to the corresponding coordination dimensions indicated in Figures 1.2 and Table 1, reduced by the size of the gap between adjacent slabs - ai indicated in Table 2.

If there are separating elements at the junction of the slabs, the geometric axes of which are combined with the coordination axes (for example, monolithic anti-seismic belts, ventilation ducts, etc.). the structural length of the slabs should be taken equal to the corresponding coordination size indicated in Figures 1. 2 and in Table 1. reduced by the size of the gap of the separating element - Og. indicated in table 2.

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

4.8 Additional dimensions taken into account when determining the structural dimensions of the slab are given in Table 2.

Table 2

Range of application of the plate	Additional dimensions taken into account when determining design size slabs, mm


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 with walls made of bricks, stones and blocks, with the exception of buildings with a calculated seismicity of 7-9 points
Buildings with walls made of bricks, stones and blocks with a calculated seismicity of 7-9 points
Frame buildings, including buildings with a calculated seismicity of 7-9 points

4.9 In the case of a slab covering a space exceeding the distance between adjacent coordination axes of the building (for example, for a slab supported by the entire thickness of the wall staircase in large-panel buildings with transverse load-bearing walls, etc.), the structural length should be taken equal to the corresponding coordination length indicated in Table 1 and increased by size - az. indicated in table 2.

5 Technical requirements

5.1 Depending on their location in the floor of the building, slabs are used for design uniformly distributed loads (without taking into account the slabs’ own weight) equal to 3.0; 4.5; 6.0; 8.0 kPa (respectively 300.450, 600.800 kgf/m2).

5.2 The working drawings of the slabs used in a particular building indicate the location of embedded parts, reinforcement outlets, local cutouts, holes and other structural details.

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

5.4 The slabs must provide a fire resistance limit in accordance with the requirements of current regulatory documents and technical documentation 4 depending on the required fire resistance of the building.

The fire resistance limit of the slabs is indicated on the working drawings.

5.5 The accuracy of the linear dimensions of the slabs should be taken according to the fifth or sixth accuracy class according to GOST 21779, taking into account the provisions of GOST 26433.0.

SP 112.13330.2012 “SNiP 21.01-97” is valid not on the territory of the Russian Federation Fire safety buildings and structures."

Requirements for the quality of concrete surfaces and appearance slabs are installed in accordance with GOST 13015 and must be recorded in the production order.

5.6 Indices of airborne noise insulation of slabs and the reduced level of impact noise under the slab, taken into account when determining the sound insulation indicators of the floor, taking into account current regulatory documents and technical documentation 2, are given in Table 3.

Table3_

Average density of concrete slab, kg/m*	Index value. dB
Average density of concrete slab, kg/m*	airborne sound insulation slab	reduced level of impact noise from an LSD stove

Notes

1 For PB type slabs, airborne sound insulation parameters are set depending on the shape and size of the voids.

2 The given level of impact noise under the slab is based on experimental results

research._

5.7 Floor structures used in floors depending on the type of floor slab are given in Table A.1 of Appendix A.

5.8 Slabs should be marked with marks in accordance with GOST 23009. When establishing designations, the following provisions must be taken into account.

The slab brand consists of alphanumeric groups separated by hyphens.

The first group contains the designation of the type of slab and overall dimensions - structural length and width.

The structural length and width of the slab are indicated in decimeters (rounded to the nearest whole number), and the thickness - in centimeters.

In the second group indicate:

The value of the design load in kilolascals.

Class of prestressed reinforcement - for prestressed slabs.

For slabs made from lightweight concrete, the type of concrete is additionally indicated, denoted by the capital letter “L”.

The third group, if necessary, includes additional characteristics reflecting the special conditions of use of the slabs, their resistance to seismic and other influences, designations of the design features of the slabs, such as the type and location of reinforcement outlets, embedded products, etc. Special conditions for the use of slabs are indicated in capital letters , design features slabs - lowercase letters or Arabic numerals.

An example of a symbol (brand) of a type 1 PK slab with a length of 5980 mm. width 1490 mm. for a design load of 4.5 kLa (450 kgf/m2), made of heavy concrete with prestressed reinforcement of class A800 (At-V):

1PK60.15-4.5A800

The same for a slab made of lightweight concrete:

1PK60.15-4.5A800L

The same for a slab supported on three sides:

1PK60.15-4.5A8003

The same for a slab supported on four sides:

1PK60.15-4.5A8004

Note - It is allowed to manufacture slabs of other sizes and mark them with marks in accordance with the working drawings standard designs before their revision.

d On the territory of the Russian Federation, SP 51.13330.2011 “SNiP 23*03-2003 Noise Protection” is in force.

Applicable floor structures

Table A.1

Appendix B (for reference)

Terms used in Appendix A

B.1 The following terms with corresponding definitions are used in Appendix A:

B.1.1 single-layer floor: Floor. oosgoyatsiya from a covering - linoleum on a heat- and sound-insulating basis, laid directly on the floor slabs.

B. 1.2 single-layer floor on a leveling screed: Pop. consisting of a covering - linoleum on a heat- and sound-insulating basis, laid on a leveling screed laid directly on the floor slabs.

B.1.3 floating floor: Floor. consisting of a coating, 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.

B.1.4 hollow floor: Floor. consisting of a hard covering along the joists and soundproofing pads laid on the floor slabs.

B.1.5 hollow-core layered floor: Floor. consisting of a hard covering and a thin soundproofing layer, laid directly on the floor slabs or on a leveling screed.

UDC 691.328.1.022-413:006.354 MKS 91.080.40

Key words: lithite, floor slab, solid slabs, hollow-core slabs, coordination dimensions, structural length and width, standard size, types, parameters, brand, concrete, class, technical requirements, reinforcement, embedded parts.

Editor EY. Shapygina Corrector L.S. Lysenko Computer layout E.K. Kuzina

Signed for publication on 02/08/2016. Format 60x84"/*.

Uel. oven l. 1.40. Circulation 37. Zak. 62.

Prepared based on the electronic version provided by the developer of the standard

FSUE "STANDARTINFORM"

123995 Moscow. Grenade Lane.. 4.

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 slabs floors are widely used in industrial and private construction in the construction of buildings for various purposes. Their use allows us to obtain a reliable and durable design that can withstand heavy mechanical loads without losing its quality characteristics.

Reinforced concrete products are used to perform 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 of staircases, 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. If the products do not have fasteners, it is necessary to think in advance about an alternative way to move them.

As a rule, 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 on the construction site. The product must be in a strictly horizontal position; immersion of reinforced concrete slabs into the ground, which leads to cracking of the floor, is strictly unacceptable. 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 a monolithic belt (width - at least 5 cm). The reinforcement frame 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. The load-bearing capacity increases significantly: for monolithic concrete structures - by 40%, and for cellular floors - by 100%.

Dimensions

On the Russian concrete products market, floor slabs are presented in 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, m 3
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 of multi-storey buildings for various purposes; the quality of the products is the key to the safe and long-term operation of the building. The slabs are produced in strict accordance with state standards, 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 environmental factors. 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, 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.

The range of laying reinforced concrete slabs - from the formation of a foundation for buildings made of wood (quick assembly), or separation of the basement from the higher body of the house, to installation attic floor upon completion top floor. Also, in addition to the usual interfloor covering, some types of panels are also used to build walls.

When covering floors, slabs are capable of not only accepting and distributing large loads(the weight of those located on them internal partitions, equipment, furniture, people), but also serve as a reliable element of rigidity in the structure of the entire building.

The products are made of heavy concrete and, in addition to increased strength and fire resistance, have high levels of water and frost resistance, as well as noise insulation. The upper and lower smooth surfaces of the product respectively serve as the floor and ceiling in the room and require minimal interior decoration.

There are several varieties of this building element. Its choice depends on the properties and characteristics of the slab required in each case, its area of application and economic calculations.

Types of slabs (classification)

According to their structural structure, reinforced concrete slabs are of 3 types:

hollow;
solid (solid);
ribbed.

Hollow core slabs

In private construction, hollow core slabs are most often used. Longitudinal round voids lighten the weight of the slab and increase its thermal insulation characteristics and allow you to hide the wires of internal utility lines in them.

Due to the popularity and widespread use of floors with longitudinal voids, their production is gradually expanding and modernizing, adapting to the emergence of new materials and construction technologies. I must say that the shape of voids can now be not only round, but also oval and vertical.

There are several brands or varieties of slabs with longitudinal voids:

PC

Widely used since Soviet times - made of heavy concrete, have round voids inside with a diameter of 140 or 159 mm, standard height 220 mm and mounting loops. Which, after laying the floor, serve as an additional embedded part for fastening the slabs together with anchors by welding.

As a rule, in private low-rise construction There is no need to fasten the slabs together after installation.

PNO (lightweight)

After some time, such modernization of these structures appeared. The product is thinner (160 mm) and weight. At the same time reinforced with a special method and thicker reinforcement, it can withstand the same loads, like the PC slab.

The use of lightweight products is considered more economical compared to PC boards in several respects:

the weight of the lightweight floor transfers less load to the foundation, and accordingly, materials are saved when constructing the base of the building;
The boards themselves are slightly cheaper than traditional PCs due to less material consumption for their manufacture;
transportation costs are reduced during transportation - a larger number of reinforced concrete products are installed on a transport unit with the same volume and weight as when loading PC slabs.

Attention!

If the ends of the holes in the purchased slabs have not been sealed at the factory, it must be done at the site of construction work - poured with concrete mortar (grade M200) in the area of support.

This product is made only from heavy concrete.

Bench panels (PB or PPS)

Reinforced concrete products of the latest generation. Products are manufactured on special stands of various widths using formless molding. This allows us to produce products whose length is not tied to GOST standards. That is, the slab is cut on a production stand for spans, in accordance with an individual project, in increments of only 10 cm. The height of the structure can also vary from 160 to 300 mm, depending on the required length.

High grade of concrete (M400 - M550) and the laying of pre-stressed lower layers of reinforcement ensure high structural strength in all dimensional options. The only disadvantage of this product can be considered its higher cost compared to PC boards.

It is the bench panels that can be mounted in vertical view- for the construction of walls of frame houses.

Attention!

During production, if a short-size slab is sawed off at the last stand, then due to excessive compression of the prestressed reinforcement, the structure may bend (with the middle bending upwards). This defect is easy to notice during visual inspection, in a stack among other products. And although such cases are quite rare, especially from good manufacturers, and up to certain values such deflection is not considered a defect, it is worth paying attention to when purchasing.

Other types of slabs

Solid single-layer (1P, 2P)- most often used in private construction for installation ceiling. They are made of cellular concrete - 120 mm thick, and heavy concrete - 160 mm thick.
Monolithic— if for some reason standard production boards are not suitable for the project, you can produce it yourself. This is a fairly simple, but long and labor-intensive process; it is justified by the possibility of application to a wide variety of forms of coverage areas. Installation required load-bearing beams, formwork and reinforcing mesh. Pouring concrete (not lower than grade M200) is kept in the formwork for the prescribed 28 days - until the design strength is fully achieved. It is believed that monolithic structures have the highest load-bearing capacity if N-grade corrugated sheeting is used when pouring them.
Ribbed- their design feature is the distribution of thickenings and thinner elements in accordance with compressive and tensile loads. Due to this, high strength and load-bearing capacity of the slab is achieved. The main application is in industrial construction and when installing foundations in high-rise buildings. But sometimes such slabs are found as garage floors. They are not used in residential construction due to the shape of the lower side, which has a concave hollow configuration and transverse stiffeners, which is inconvenient for finishing.

Ribbed floor slabs

Difference between PC and PB boards

If you have chosen hollow core slabs, let's take a closer look. Let's look at the differences between traditional PC boards and bench panels with formless PB molding.

For convenience, the data is given in the table:

PC and PNO		PB or PPP
	Thickness
PC - 220 mm, lightweight - 160 mm		from 160 to 300 mm
	Length
PC - up to 7.2, sometimes up to 9 m, PNO - up to 6.3 meters, with a step determined by each manufacturer individually		The maximum length is 12 m, structurally depending on the height of the panel. The slabs are cut to length to order, with a step size of 10 cm.
	Width
1.00; 1.20; 1.50 and 1.80 m		Most often stands are 1.2 m, less often - 1.00 and 1.50 m

Basically - typical - 800 kgf/m2, but individual production with a load of 1250 is possible		In addition to the standard load of 800, slabs with loads from 300 to 1600 kgf/m2 are produced
	Armature
The bottom layer of reinforcement is subjected to prestressing only in slabs with a length of 4.2 m or more. In shorter products, simple mesh reinforcement is used.		The reinforcement is subjected to prestressing in products of any length.
	Smoothness
Because of long term service and wear of equipment, the concrete surface, as a rule, does not have the desired smoothness.		The latest benches and extruder smoothing provide a smoother, more attractive finish, but some minor exceptions are acceptable.
	Concrete grade
M200 - M400		M400 - M550
	Hole ends
Mandatory sealing of the ends of the holes		Not required due to the strength of the concrete grade

Calculation of the number of slabs and dimensions for a private house

If the construction of private housing is carried out according to an approved project, then the dimensions and number of slabs are pre-calculated by engineers when developing this order. In general, such calculations are made according to the principle “adjusting” the wall layout to the size of the slabs, and not vice versa. But in private construction anything can happen. And if the walls are already planned or even ready and waiting to be covered, then their number and dimensions need to be calculated, taking into account certain rules:

the length of the slab is equal to the distance between the load-bearing walls plus the width of the area where the slab rests on the wall (beam);
The width of the slab is selected based on how many pieces from the assortment you have chosen will cover the transverse distance between the main walls (partitions are not taken into account). The long side of the hollow core slab is laid flush against non-load-bearing walls, or overlapped by no more than 100 mm (to the first void). For more details, see the article about;
if there is a small gap between the slabs or there is a small area of the room that does not fit into the configuration of the slabs, it can be “closed” by partial monolithic filling, using formwork and reinforcement;

It is better to order products of “non-selling” sizes in advance, since waiting for their production takes more time than the production of standard designs.

Attention!

In winter, floor slabs are noticeably cheaper. But the area for unloading them needs to be prepared and leveled in the fall. You will also have to order a tractor to clear snow on the site and, possibly, on the driveways. But in the end there will still be savings.

Standard slab sizes

Still, if possible, it is better to use slabs standard sizes, since their acquisition costs much less and takes less time.

At factories, the size ranges of the latest generation of products vary somewhat, but there are size restrictions generally accepted by standards and specifications:

Type of plate	Length (m)	Width (m)
PC, round voids with a diameter of 140 mm	1,8 / 2,4 / 3,0 / 6,0	from 1.2 all sizes are multiples of 0.3 m
PC, round voids with a diameter of 159 mm and PB slabs	2,4 / 3,0 / 3,6 / 4,2 / 4,8 / 5,1 / 6,0 / 6,3 / 6,6 / 7,2 sometimes 9.0	from 1.0 onwards all sizes are multiples of 0.3 m
PNO height 160 mm	from 1.6 to 6.3, sometimes 9.0	0,64 / 0,84 / 1,0 / 1,2 / 1,5
teaching staff	from 3 to 12, in 0.1 m increments	1,0 / 1,2 / 1,5
solid 120 mm high	3,0 / 3,6	4,8 / 5,4 / 6,0 / 6,6
solid 160 mm high	2,4 / 3,0 / 3,6	2,4 / 3,0 / 3,6 / 4,8 / 5,4 / 6,0
ribbed, height 30 mm	6,0	1,5

Weight

It is important to know the weight of the slabs when calculating structures. But this is the concern of the designer who draws up the project for the house. It is useful for a private developer to know the weight of the slabs when delivering them to the site and installing them.

In the first case, it is necessary to select the carrying capacity of the transport. Most likely, two vehicles will be needed for delivery.

To install the slabs, a crane is used, when ordering it you will also be asked about the weight and dimensions of the slabs. Each crane has its own lifting capacity. Since the weight range of the slabs is from 960-4800 kg, a 5-ton truck is enough in any case.

Depending on the concrete used, the mass of a standard 6x1.5 m hollow core slab varies from 2.8 to 3.0 tons.

Since slabs with a thickness of 160 mm and 220 mm are most common in private construction, we give their weight by linear meter for slab width 1500 mm:

Here are some more standard slabs:

Marking of slabs

According to GOST, all types of slabs have their own standards. Their observance is necessary when designing objects and during installation calculations. Each slab is marked with a special encrypted inscription that reflects not only overall dimensions products, but also its main strength and design characteristics. Having understood the meanings of one brand of slabs, you can easily read the others, regardless of whether the slab sizes are standard or custom-made.

The first letters in the specification indicate the type of construction (PC, PNO, PB, PPS). Next, through a hyphen, there is a listing of the length and width values (in decimeters, rounded to a whole number), and again through a hyphen - the maximum permissible weight load on the structure, in centners per m 2, without taking into account its own weight (only the weight of partitions, interior decoration, furniture , equipment, people). At the end, a letter addition is possible, indicating additional reinforcement and type of concrete (t - heavy, l - light, i - cellular)

Let's look at an example and decipher the markings. Slab Specification PK-60-15-8AtVt means:

PC – slab with round voids;
60 – length 6 m (60 dm);
15 – width 1.5 m (15 dm);
8 – the structure can be mechanically loaded up to 800 kg per m2;
AtV - presence of additional reinforcement (AtV class)
t - made of heavy concrete.

The height of the product is not indicated, because refers to the standard size of this product (220 mm).

Also, the letters in the markings inform:

PC - standard slab with round voids,
NV – single-row reinforcement;
NKV – double-row reinforcement;
4НВК – four-row reinforcement.

Useful video

A representative of one of the factories talks about the size of their products:

This article is for informational purposes and provides a general overview of reinforced concrete floors. Considering the impressive weight of structures, when using them, it is desirable to have an engineering calculation of foundations and load-bearing walls, taking into account the required safety margin.

Looking at stacks of reinforced concrete slabs, the average citizen has no idea how much important information they can convey to a specialist builder. This is not surprising, because in everyday life we rarely encounter such structures.

If we are talking about a new building, then the customer installation work It will be useful to know what types and sizes of floor slabs exist, as well as what their maximum load-bearing capacity is according to GOST.

At first glance, the differences between hollow core 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 communications, violating the integrity of the working fittings. Otherwise the plate may lose 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 in 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 than formwork manufacturing, so 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 standard panels do not fit. Builders get out of the situation by filling such “blank spots” with monolithic concrete directly 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 of a sewer riser (with a diameter of 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).

The load-bearing capacity of a standard slab ranges 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 of hollow core slabs are used in construction, so a separate article would have to be devoted to a detailed description of their prices. 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 for high-quality installation of panels is strict adherence to the design parameters for 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 (with 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 slab should be laid underneath them. reinforced belt. 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.

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.

Such floor slabs (PCS), although they have significantly more weight, which ultimately increases both the load on the building and the cost of construction, however, have a large margin of safety. The 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 multi-hollow panel slabs, the length of which is 6000 mm and the width is 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 multi-hollow panels can have 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 of utmost 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 of the 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:

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- main component of the load;
The lower part, with the presence of the ceiling, its decoration, and lighting fixtures. By the way, you shouldn’t be skeptical about the availability of lighting fixtures. Firstly, the same LED lamps require partial destruction of the plate 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;
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 impact. It is unlikely to fall, but there may subsequently be serious problems with ventilation.

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, calculations for floors and hollow core slabs during construction will still need to be made.

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 symbols 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. Last digit (in in this case- 10) 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 the limiting impact is a mandatory 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 exactly 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 load value 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 (500kg/m²) you need to subtract the resulting one (200kg/m²). The result will be a figure of 300 m². But that's not all.

Diagram of a hollow core slab with waterproofing

Now from this indicator it is necessary to subtract the weight of furniture, finishing materials, and the weight of people who will constantly be in the room or 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 hollow core slab floors

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

This is not even fraud, it is a criminal offense that should 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 various types hollow slabs.