If you have at least once encountered the construction process or carried out apartment renovations, then you should know what hollow-core floor slabs are. Their importance is difficult to overestimate. Design features, its main characteristics and markings are taken into account during the work process. This knowledge allows you to determine what the limit of useful and decorative loads the slab can withstand.
The size and type of the product affect its final price. The length of the described slabs can be equal to the limit from 1.18 to 9.7 m. As for the width, it is limited to a value from 0.99 to 3.5 m.
The most popular are those products whose length is 6 m, while their width usually reaches a maximum of 1.5 m. The minimum value is 1.2 m. Getting acquainted with the dimensions of hollow core slabs, you can understand that their thickness remains unchanged and is equal to 22 cm. Given the impressive weight of such structures, an assembly crane is usually used for their installation; its capacity should be 5 tons.
Any overlap in the structure has three parts, among them:
The first is where the residential floor above is located. This includes flooring, insulation materials and screeds. The bottom is the surface non-residential premises. This includes hanging elements and ceiling finishes. As for the structural part, it combines the above and holds them in the air.
Hollow-core floor slabs serve as a structural part. A constant static load is exerted on it Decoration Materials, used in the design of ceilings and floors. This means elements suspended from the ceiling and installed on top of it, namely:
In addition, you can also highlight dynamic load. It is caused by objects moving on the surface. In this case, one should take into account not only the mass of a person, but also domestic animals, which today are quite exotic (tigers, lynxes, etc.).
The above types of loads can be applied to hollow core floor slabs. A point punch, for example, is an impressively sized punching bag suspended from the ceiling. As for the suspension system, it interacts with the suspensions at regular intervals with a frame and exerts a distributed load.
These two types of load can have a complex effect. IN in this case the calculation will be more complicated. If you install a bathtub that holds 500 liters, then you should take into account two types of load. The filled container is distributed on the surface of the support between the points of contact. There is also a point load, which is exerted by each leg individually.
The load on hollow core slabs can be calculated by you. These manipulations are carried out in order to find out how much the product can bear. Afterwards it is necessary to determine what the ceiling will bear. This should include partitions, materials based on insulating layers, parquet flooring and cement screeds.
The total weight of the load must be divided by the number of slabs. Roof supports and load-bearing supports should be located at the ends. The internal parts are reinforced in such a way that the load is applied to the ends. The central part of the slab is not capable of supporting the weight of serious structures. This is true even if there are main walls or support columns below. Now you can calculate the load on the hollow core slab. To do this, you need to find out its weight. If we take a product marked PK-60-15-8, then we can say that its weight is 2850 kg. It is manufactured according to state standards 9561-91.
The first step is to determine the area of the bearing surface of the product; it is 9 m2. To do this, 6 must be multiplied by 1.5. Now you can find out how many kilograms of load this surface can bear. Why do you need to multiply the area by the permissible load by one? square meter. As a result, you will be able to get 7200 kg (9 m2 multiplied by 800 kg per m2). From here you should subtract the mass of the plate itself and then you will be able to get 4350 kg.
Then you need to calculate how many kilograms the floor insulation will add, floor coverings and screed. Usually in work they try to use such a volume of solution and thermal insulation so that the materials together do not weigh more than 150 kg/m2. With a surface area of 9 m2, the hollow core slab will carry 1350 kg. This value can be obtained by multiplying by 150 kg/m2. This number should be subtracted from the previously obtained figure (4350 kg). Which will ultimately allow you to get 3000 kg. Recalculating this value per square meter, you get 333 kg/m2.
According to sanitary standards and rules, a weight of 150 kg/m2 must be allocated to static and dynamic load. The remaining 183 kg/m2 can be used for installation decorative elements and partitions. If the weight of the latter exceeds the calculated value, then it is recommended to choose a lighter floor covering.
For large-panel buildings for various purposes Hollow core slabs must be used. They are manufactured according to the above state standard and can be based on the following materials:
The manufacturing technology, which involves the presence of voids, provides structures with excellent sound insulation properties and low weight. They are ready to serve for a long time and have good strength characteristics, which are due to the use of steel ropes and reinforcement.
During installation, such products are located on supporting structures. Round voids can have a diameter of up to 159 mm. The dimensions of hollow core slabs are one of the factors by which products are classified. The length can reach 9.2 m. As for the width, the minimum is 1 m and the maximum is 1.8 m.
The class of concrete used corresponds to B22.5. Density is equal to the limit from 2000 to 2400 kg/m 3. State standards also specify the grade of concrete taking into account frost resistance, it looks like this: F200. Hollow slabs (GOST 9561-91) are made of concrete with a strength within 261.9 kg/cm 2.
Reinforced concrete products cast in a factory are subject to marking. It is encoded information. The slabs are designated by two capital letters PC. This abbreviation is next to the number that indicates the length of the product in decimeters. Next are the numbers indicating the width. The last indicator indicates how much weight in kilograms 1 dm2 can withstand, taking into account its own weight.
For example, a reinforced concrete hollow core slab PK 12-10-8 is a product with a length of 12 dm, which is 1.18 m. The width of such a slab is 0.99 m (approximately 10 dm). Maximum load per 1 dm 2 is 8 kg, which is equal to 800 kg per square meter. In general, this value is the same for almost all hollow core slabs. As an exception, there are products that can withstand up to 1250 kg per square meter. You can recognize such slabs by their markings, at the end of which there are numbers 10 or 12.5.
Interfloor hollow core slabs are manufactured using conventional or prestressed reinforcement. In addition to load-bearing capacity, panels must also meet sound insulation requirements. For this purpose, the product is provided with holes, which may have a round or other cross-section. Such structures belong to the third category of crack resistance.
In addition to these characteristics, you may also be interested in the cost. You will have to pay 3,469 rubles for a hollow core slab weighing 0.49 tons. In this case we are talking about a product with the following dimensions: 1680x990x220 mm. If the weight of the slab increases to 0.65 tons, and the dimensions become 1680x1490x220 mm, then you will have to pay 4,351 rubles. The thickness of the hollow core slab remains unchanged, which cannot be said about the other parameters. For example, you can purchase a product with dimensions equal to 1880x990x220 mm for 3,473 rubles.
If the floor slab is manufactured at the factory, then in the process they are used state standards. They guarantee high quality products and compliance with hardening time and temperature conditions. The solid type of slab is distinguished by its impressive weight and, accordingly, high cost. This explains the fact that similar products most often used in the construction of important buildings.
Floor slabs have found their popularity and are widely used in the construction of residential buildings and are lighter in weight compared to solid slabs, and they are cheaper. But in matters of reliability and strength they are not inferior. The location of voids and their number do not in any way affect the load-bearing properties of the slab. In addition, they make it possible to achieve higher sound and heat insulation properties of the structure.
But no matter how light they are considered, their installation cannot be done without appropriate lifting equipment. This allows you to increase the accuracy of installation and complete construction in a shorter time. These products are also good because they are manufactured in a factory, which means they undergo quality control.
GOST 9561-91 contains the requirements mandatory for the manufacture of hollow-core 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
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 of Industrial Buildings and Structures (TsNIIPromzdanii) 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 Resolution of the USSR State Committee for Construction and Investment dated September 20, 1991 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
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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.
1.1. 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 the separating element, for example, an anti-seismic belt, ventilation ducts, crossbar ribs), or increased by the value a(3) (for example, for slabs supported by the entire thickness of the staircase walls of 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
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Drawing number |
Coordination dimensions of the slab, mm |
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From 2400 to 6600 inclusive. at intervals of 300, 7200, 7500 |
1000, 1200, 1500, 1800, 2400, 3000, 3600 |
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1000, 1200, 1500 |
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From 3600 to 6600 inclusive. at intervals of 300, 7200, 7500 |
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From 2400 to 3600 inclusive. at intervals of 300 |
From 4800 to 6600 inclusive. at intervals of 300, 7200 |
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From 2400 to 6600 inclusive. at intervals of 300, 7200, 9000 |
1000, 1200, 1500 |
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6000, 9000, 12000 |
1000, 1200, 1500 |
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1000, 1200, 1500 |
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From 3600 to 6300 inclusive. at intervals of 300 |
1000, 1200, 1500, 1800 |
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6000, 9000, 12000 |
1000, 1200, 1500 |
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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 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
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Scope of application of plates |
Additional dimensions taken into account when determining the structural size of the slab, mm |
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width a(1) |
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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 |
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Buildings (structures) with walls made of bricks, stones and blocks, with the exception of buildings (structures) with a calculated seismicity of 7-9 points |
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Buildings (structures) with walls made of bricks, stones and blocks with a calculated seismicity of 7-9 points |
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Frame buildings (structures), including buildings (structures) with a calculated seismicity of 7-9 points |
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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 the holes in the slabs intended for loopless installation are taken according to the drawings included in the design documentation of the 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 designation of the design features of slabs (for example, the presence of additional embedded products).
Example symbol(grade) slab type 1PK 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;
according to the average density of 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 a load-bearing part of loggias must also satisfy additional requirements 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. Values of actual deviations geometric parameters slabs should not exceed the limits specified in the table. 3.
Table 3
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Name of deviation of geometric parameter |
Name geometric parameter |
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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 |
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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 |
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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: |
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* 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 with paste-like compounds, 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 of 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 the side faces or 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.
2.1. 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 in the future - when making design changes to them and when changing manufacturing technology, 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).
3.1. 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 a concrete mixture of the working composition and stored under the conditions established by GOST 18105.
When determining the strength of concrete using methods non-destructive testing 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 allowed 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 of the necessary equipment, cutting furrows and exposing the slab reinforcement with subsequent sealing of the furrows is allowed. Furrows should be punched at a distance from the ends not exceeding 0.25 times the length of the slab.
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 it is allowed to transport slabs in an inclined or vertical position.
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.
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 |
|
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 |
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 |
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 text of the document is verified according to:
official publication
Gosstroy USSR - M: Standards Publishing House, 1992
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 it will be useful for the customer of installation work to know what types and sizes of floor slabs exist, as well as what their maximum load-bearing capacity is according to GOST.
At first glance, the differences between hollow core slabs are only in their length, thickness and width. However, specifications These structures are much more extensive, so we will look at them in more detail.
All basic requirements for hollow core slabs, including their purpose and strength characteristics, describes GOST 9561-91.
First of all, it indicates the gradation of the slabs depending on their thickness, the diameter of the holes and the number of sides with which they rest on the walls.
In addition to different thicknesses and geometric dimensions Hollow-core floor slabs are classified according to the method of reinforcement. GOST indicates that panels that rest on walls on 2 or 3 sides must be made using prestressed reinforcement.
The practical conclusion that follows from this for the developer is that you cannot punch holes for engineering Communication, violating the integrity of the working fittings. Otherwise, the slab may lose its load-bearing capacity (crack under load or collapse).
Clause 1.2.7 of GOST 9561-91 makes important exceptions, allowing for the manufacture of certain types of slabs not to install prestressed reinforcement in them.
They refer to the following panels:
If such reinforced concrete floor slabs were brought to your site, and their passport indicates non-prestressed reinforcement, do not rush to send the car back to the factory. These structures comply with building codes.
Floor slabs are made in different ways, which affects 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 in such “blank spots” monolithic concrete right on site. The quality is so homemade design noticeably inferior to that achieved in factory conditions (vibration compaction and steaming of concrete).
The advantage of PC and PG panels over PB panels is that you can punch holes in them for communications without fear of structural destruction. The reason is that their void diameter is at least 114 mm, which allows free passage sewer riser(diameter 80 or 100 mm).
PB slabs have narrower holes (60 mm). Therefore, to pass the riser, you have to cut the rib, weakening the structure. Experts say that such a procedure is unacceptable only for high-rise construction. When constructing low-rise housing, punching holes in PB slabs is allowed.
There are a lot of them and they are all quite significant:
Here everything is unified to the maximum so that it is possible to make a design of any installation size. The gradation of the width and length of the slabs occurs in increments from 100 to 500 mm.
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:
The third group of markings contains additional characteristics that reflect the special conditions of use of structures (resistance to aggressive gases, seismic influences, etc.). In addition, the design features of the slabs (the presence of additional embedded parts) are sometimes indicated here.
As an example to explain the principle of marking hollow-core panels, consider the following design:
Hollow-core panel type 1PK, length 6280 mm, width 1490 mm, designed for a load of 6 kPa (600 kg/m2) and made of lightweight concrete using prestressed reinforcement class At-V).
Its marking will look like this: 1PK63.15-6AtVL. Here we see only two groups of characters.
If the slab is made of heavy concrete and is intended for use in a seismic zone (seismicity up to 7 points), then a third group of symbols appears in its designation: 1PK 63.15-6AtV-C7.
The considered technical characteristics of floor slabs determine their scope of application.
All types of hollow-core panels are calculated based on the standard load on the floor - 150 kg/m2 (weight of people, equipment and furniture).
Load bearing capacity standard plate is in the range from 600 to 1000 kg/m2. Comparing the standard of 150 kg/m2 with the actual strength of the panels, it is easy to see that their safety margin is very high. Therefore, they can be installed in all types of residential, industrial and public buildings.
|
Slab type |
Reduced slab thickness, meters |
Average density of concrete slab, kg/m3 |
Slab length, meters |
Building characteristics |
| 1pcs,1pkt, 1pcs |
up to 7.2 inclusive |
Residential buildings (sound insulation of premises is ensured by installing floating, hollow-core, hollow-core or layered floors, as well as single-layer screed floors | ||
| 1pc | ||||
| 2PK, 2PKT, 2PKK | Residential buildings in which sound insulation of residential premises is ensured by installing single-layer floors | |||
| 3PK, 3PKT, 3PKK | ||||
| 4pcs | Public and industrial buildings | |||
| 5pcs | ||||
| 6pcs | ||||
| PG | ||||
| 7pcs | Residential buildings (low-rise and estate type) |
This table contains the given thickness of the slab - a term that is 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.
Dozens of standard sizes of hollow core slabs are used in construction, so a detailed description of their prices would have to be devoted to a separate article. We will indicate the price parameters of the most popular panels (pickup):
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 excessive support 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:
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 should be constantly monitored. front surfaces at adjacent panels. 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:
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 of the 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 internal partitions, equipment, furniture, people located on them), 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 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 finishing.
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.
According to their structural structure, reinforced concrete slabs are of 3 types:
In private construction, hollow core slabs are most often used. Longitudinal round voids lighten the weight of the slab, increase its thermal insulation characteristics and make it possible to hide the wires of internal utility lines in them.
Due to popularity and wide application 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:
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 it is not necessary to fasten the slabs together after installation.
After some time, such modernization of these structures appeared. The product is thinner (160 mm) and weight. Wherein 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:
Attention!
If the ends of the holes in the purchased slabs are not sealed at the factory, it must be done at the production site. construction work- pour in concrete mortar(grade M200) in the support area.
This product is made only from heavy concrete. 
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 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 more high cost compared to PC slabs.
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 in good producers, and up to certain values, such a deflection is not considered a defect; you should pay attention to this when purchasing.
Ribbed slabs floors 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 molding PB.
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 possible custom production with load 1250 | 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 | ||||
| Due to the long service life and wear of equipment, the surface of concrete, 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 |
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:
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 access roads. But in the end there will still be savings.
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 standards and TU:
| 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 |
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.
Used for installation of slabs crane, when ordering 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: 
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 the overall dimensions of the product, 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:
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:
A representative of one of the factories talks about the size of their products:
This article is for informational purposes only and provides a general overview. 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.
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 There are solid (full-bodied) and hollow varieties. 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 specifications and marking is 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 a smooth surface, optimal for laying ceilings. They are in demand in private construction, valued for their ease of finishing; their use implies the abandonment of suspended systems. A significant part is made of 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 flat surface, on the other hand, 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:
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 literal expression: 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 |
