Central Institute of Regulatory Research
And scientific and technical information "Orgtranstroy"
Ministry of Transport Construction

Operating technological maps

Production of reinforced concrete
Pre-tense
Plate overlap by
Flow-aggregate technology

Moscow 1977.

Operational technological cards were developed by the department for improving technology at industrial enterprises and the nature of the nature of the institute "OrgTranstroy" (performers V.V. Yudin) with the participation of the Tula NIS (performer Ya.B. Bryzhezhev), Rostov NIS (performer Yu.M. Popov) and Kuibyshev NIS (performer V.I. Khudyakov) of the Ministry of Transport Construction.

Editor V.T. Mikhailov

I. General instructions

Technological operating cards are designed on the basis of studying the production of work in the manufacture of hollow slabs of overlap of the II-04 series on the Orenburg, Ryazan and Beslan ZBB CHBC plants for the Ministry of Transport Construction for Flow-Aggregate Technology.

Maps are designed for workers, brigadiers and engineering and technical workers.

Plates of overlaps are manufactured according to the drawings developed by the Moscow Institute of Model and Experimental Design MITEP. Technological maps It can be applied in the manufacture of similar slabs of the overlap of the connected version of the II-04 series, developed by the Central Research Institute of Experimental Designing of Training Buildings, together with the Scientific Research Institute of Concrete and Reinforcement of the USSR State Institute. Working drawings were approved by Order No. 173 of August 13, 1973 of the State Committee for Civil Engineering and Architecture at the USSR Association and were put into effect from October 1, 1973.

The basis of technological maps includes the technology of manufacturing a plate of overlapping type PC8-58-12. The same cards can also be applied in the manufacture of other types of hollow-out plates of the II-04 series.

Technical characteristics of the plane of the PC8-58-12

Brand concrete - 200

Concrete volume - 0.8 m 3

Steel consumption - 39.2 kg

Plate Mass - 2 t

dimensions (Fig.):

length ( l.) - 5760 mm

width ( in) - 1190 mm

height (H) - 220 mm

The limit deviations from the design sizes of the ceiling slabs are adopted in accordance with GOST 13015 -75 "Reinforced concrete and concrete products"

in length δ 1 ± 8 mm

by width δ 2 ± 5 mm

in height δ 3 ± 5 mm

Deviations OT nominal sizes Holes in the product should not exceed± 5 mm.

Deviations from straightness of the real profile of the product surface in any section at a length of 2 m, characterized by the magnitude of the largest distance from the actual profile points to the adjacent straight, should not exceed:

The number of sinks permissible sizes on any section of the facial concrete surface area0.04 m 2 (200 × 200 mm) should not exceed - 5.

Fat and rusty spots are not allowed on the facial surfaces of the products.

The quality of smooth concrete surfaces must be consistent with the approved reference to the product.

The standard of products is coordinated by the manufacturer with a consumer, a design organization that binds the project of a building or structure, and the bodies of state architectural and construction control.

In the concrete, the product supplied to the consumer, cracks are not allowed, with the exception of shrinking and other surface technological cracks, the width of which should not exceed 0.1 mm.

Cube concrete strength By the time of vacation of products from the factory should be in winter conditions not lower than 100% project, and in the warmtime not lower than 70%, and the plant manufacturer in this case should guarantee the achievement of 100% strength at a 28-day age.

As a large aggregate, fractionated crushed stone applies, which meets the requirements of GOST 10268-70.

As a fine filler, sand is used that meets the requirements of GOST 10268-70.

Unfolded fittings for plates of overlappings are taken from steel class A-1, B-1 as welded grids and frames. Unfolded fittings and mortgages must meet the requirements of GOST 10922 -75.

Strained longitudinal working fittings project is provided for the usual version of the class A-IV , and for the bonding version of the class A-V.

The reinforcement is tensioned by an electrothermal method on the pallet stops followed by the transmission of tensioning efforts to concrete after it is hardening.

Mortgage parts and mounting loops The manufacturer gets centrally.

Flat frames and reinforcement grids are manufactured in the reinforcing workshop in special templates by contact-point welding on welding machines.

The use of arc electric welding instead of contact-point is prohibited.

For the manufacture of the ceiling slab are provided by the concrete brand 200 and 250.

The concrete mix must meet the requirements of GOST 7473 -61.

The following materials are used as lubrication:

emulsol - 10%

soda Calcined - 0.4 - 0.8%

water - 89.6 - 89.2%

It is allowed to apply other types of lubricant in accordance with the instructions for their use.

The heat-woofer treatment plates of floors is made in a steady chamber of a yam type. The thermal processing mode is made in accordance with the instructions of the "Guidelines for thermal processing of concrete and reinforced concrete products", M., NIIZB - VNIRIZHESTON, 1974.

To obtain 70% of the strength of concrete from the design brand, the following thermal material processing mode is recommended:

exposure of products in the chamber at a temperature of 20 - 30 ° C - 2 h;

uniform temperature rise from 20 - 30 to 75 - 80 ° C - 2 h;

isothermal heating at a temperature of 75 - 80 ° C - 4 h;

reduced temperature from 75 - 80 to 30 ° C - 2 h;

exposure of products after steaming - 2 h.

The full cycle of heat-woofer processing of products under the specified mode lasts 12 hours.

Relative humidity in the chamber should be about 100%.

Depending on the type of cement, the composition of the concrete mixture and the release strength mode of heat-woofer is subject to adjustment of the plant's laboratory.

The quality of the slabs of the overlap is controlled by working drawings, and the source materials - according to the current standards.

In the absence of a factory passport on its cement completelytested in accordance with GOST 310-60.

Each party of rubble and sand must have a passport. The factory produces a control check for the quality of aggregates in accordance with the requirements of GOST 8269-64.

When preparing a concrete mixture should be checked:

the correctness of the weighing of the components;

mobility (at least two times in shift, as well as with every change in the humidity of the aggregates);

the duration of mixing (no less than once in shift).

The quality of manufacturing products is controlled by marking them, adherence, acceptance rules, storage conditions and transportation, test methods and other technical requirements in accordance with GOST 13015 -75.

Technological cards provide for the manufacture of slabs of overlapping with two links:

Fig. 2. . Workplace organization scheme:

1 - post of cleaning and lubrication; 2 - racks for reinforcement grids; 3 - rack for reinforcement rods; 4 - Electric heating; 5 - tank for lubrication; 6 - pallets; 7 - wardrobe for a fishing rod; 8 - cabinet for the tool; 9 - racks for grids; 10 - racks for frames; 11 - racks for loops; 12 - control panel; 13 - vibrationboard; 14 - form machine; 15 - concrete stage; 16 - concreteradatik; 17 - overpass; 18 - tool box; 19 - vibroprigru; 20 - post of aging of products; 21 - passing chambers; 22 - electric welding transformer; 23 - wardrobe for welding machines; 24 - tool box; 25 - post of platform

From the operator control panel, injection of emptying agents and lateral side sides are produced. Then both workers install vertical flat reinforcement frames, upper mesh, mounting hinges and locking of the protective layer. After that, they are filled with a concrete mixture of a concrete-layer with a resurrection of it. After laying a concrete mixture into shape, it is sealing on the vibrationboard using a vibroprigruz.

After that, the operator from the control panel displays the hollow and longitudinal sides of the formwork.

Then both workers start the finishing of the freshly-appointed product and install the pallet with the product in the opposer chamber.

The second link performs operations in the following sequence: the reinforceer is 3 solid. The reinforcement is blank on the C-370 machine, after which it goes to the CM-516A machine for bending grid and produces bending grids C-5, electric welder 4 solid. On a single-point welding machine, MTP-200 welds frames and lower reinforcement grids, then it moves to the MTMS multipoint welding machine and welds the C-24 grid.

Production of reinforcement strained rods and mounting loops The maps are not provided, since the plant receives them centrally.

The work of the driver of the bridge crane is paid again, so it is not part of the brigade.

II. Safety Instructions, Industrial Sanitation

In the manufacture of slabs, the floors must be observed "the rules for safety and industrial sanitation in the production of concrete and reinforced concrete products", M., Orgtranstroy, 1974.

To create favorable working conditions in the workshop it is necessary: \u200b\u200bjobs to remove in the process of work and by the end of the shift, used tools and fixtures to be placed on special racks in the posts zone.

Mold lubrication must be stored near the platform posts, when carrying and using lubrication, prevent it from entering the floor.

The temperature in the workshop should be maintained 16 - 18 ° C with relative humidity of at least 60 and no more than 80%.

Workers must be provided with overalls in accordance with standards.

In accordance with the sanitary standards, the noise level must be no more than 90 dB. The administration is obliged to carry out activities to reduce noise in the production facilitation.

Plates of floors with round voids are stored in a stack of not more than 2.5 m high.

Strops for mounting hinges automatic traverse.

Persons not under the age of 18 years old who have passed medical examination, training for the installed program and learned safety and alarm systems are allowed to make the floor slabs.

Workers engaged in the manufacture of slabs of floors must study the standard instructions on labor protection by profession: " Typical instruction ON SECURITY FOR SECURITY FOR ARMATURICS ", M., ORGTRANSSTROY, 1977," TYPE SECURITY INSTRUCTIONS for passages and autocovers ", M., Orgtranstroy, 1963," Typical safety instructions for a welder operating on machines contact welding, and for electric welders automatic and semi-automatic arc welding", M., Orgtranstroy, 1971, as well as SNiP III-A.11-70, "Safety in construction" section 5 "Electric welding works".

Reinforced concrete wetting plates of floors are manufactured in accordance with GOST 9561-91 and are used to overlap the spans of residential and public buildings.

Almost no building do without the use of these products. If for the arrangement of foundations concrete blocks The FBS is equivalent to the replacement in the form of a bay foundation, pile, etc., then there are practically no alternatives to empty slabs. Any other solutions (monolithic reinforced concrete structures or wood floors) are inferior or in strength or in ease of manufacture.

From this article you will learn:

• what is the difference in PC plates from PB,
• how to calculate permissible load on the panel
• what caused the deflection slabs and what to do about it.

Differences of hollow plates of PC overlaps and PB

IN last years replaced in the turnover soviet time The plates of the PC overlap come products of a new generation - the wet-free bench panels of the non-blank molding of the PB brand (or PPS depending on the project).

If the PC reinforced concrete plates are manufactured according to the drawings of the 1.141-1 series, then a single document, on the basis of which the bench panels produce, no. Usually, plants use working drawings provided by equipment suppliers. For example, a series of 0-453-04, IZh568-03, IL 620, IL 509-93 and a number of others.

We reduced the main differences between PC plates and PB into one table.

Load for wetting plates of overlapping

In practice, the question often arises, which load is capable of carrying a reinforced concrete wetting plate of the overlap, whether it will break from a voltage.

In any case, the bearing wall should not be based on it. Capital (carrier) walls can rely strictly or on foundation blocks, or on the same walls of the lower floors.

Where the panel is overwhelmed on carrying wall, it is additionally strengthened - from the ends of the hole of the voids are poured with concrete, and on the sides it is not recommended to make a total of more than 100 mm, i.e. up to the 1st emptiness.

Load can be distributed or point. For a distributed load, everything is simple - to calculate the plate area in m2, multiplied by the load according to the marking (as a rule it is 800 kg / m2) and subtract your own slab weight. So for PCs 42-12-8 we have area \u003d 5m2. Multiply with 800 \u003d 4 tons. And we subtract your own weight \u003d 1.53 tons. The remaining 2.5 tons and will be permissible distributed load. You can, for example, pour it with a concrete tie 20 cm.

For point loads, it is difficult to give a similar calculation, since the carrier capacity of the plate in the case of point pressure depends not only on body weight, but also from the application point. So at the edges of the panel is much stronger than in the center. Usually it is recommended not to exceed the rated load by more than 2 times, i.e. up to 1.6 tons in the absence of other effects.

In practice, it is more often to calculate the combined load from different sources, such as screed, furniture, people, non-vacant partitions. Here you should trust the experience of the Soviet Research Institute, which took the load "8" typical, i.e. Sufficient use for all "standard" cases.

Their calculations are based on the following considerations:

• own weight \u003d 300 kg / m2
• screed + Flippers \u003d 150 kg / m2 (approximately 6-7 cm.
• furniture + people \u003d 200 kg / m2
• wall / partitions \u003d 150 kg / m2

If in your case these indicators are significantly higher, it is possible to think about purchasing panels with higher bearing capacity.

The wetting plates of overlappings, due to the reinforcement and properties of concrete, distribute the weight of the object of the object to the large surface than the actual contact area. For example, if your partition has a width of 100 mm., And near her there are no other loads, then this pressure will be distributed for a larger surface and will not be outside the limits embedded in the calculations of the limit norms.

You should also not forget that in addition to constant (static) loads there are variables (dynamic). For example, standing on the floor of the hih will have a significantly less destructive impact than fallen from the cabinet. Therefore, dynamic loads on the panel should be avoided if possible.

Deflection slabs

Sometimes buyers face a situation where the reinforced concrete slabs of the floors have a different deflection, including in the opposite direction. It should be known that according to SNIP 2.01.07-85 "load and exposure" of the deflection of over 1/150 part of the product length is not a marriage. So for the most problematic PB 90-12, the permissible value of the deflection is as much as 6 cm.

Reverse deflection is most often formed when the last plate of the PB overlapping is discharged on the stand when its length is significantly less than the length range for which the stand was initially prepared. For longer plates, larger tension is given and because The main reinforcement goes along the bottom surface of the plate, when dipped a short plate, this excess compression force seems to be fused the plate.

To avoid this situation, customers should carefully examine the products before purchasing. Usually, reinforced concrete slab With a big deflection, it is not difficult to notice in the stack of other hollow plates. It should be recognized that these cases are still rare and good manufacturers Practically do not meet.

Answer to the question of the admissible design of the panels on the walls you will find in our article

Plates of overlap - inexpensive, convenient and indispensable, in many cases, building materials. With their laying, you can complete the construction of the garage, to separate the basement from the main building building, withdraw the floors or use as part common design Roofs. Like another similar construction material from reinforced concrete used in different areas Building and laying underground gas highways, the slab overlap there are several kinds of varieties. They differ in several parameters having their characteristics.

Application of slabs of overlapping in mounting works

The extensive scope of application slabs is quite explained - this is a great material for typical construction, for the high-speed construction of retail space, facilities industrial enterprises and other objects. Occasionally used for private home ownership, for example, for laying on the foundation over the basement or base level. They are great for the rapid construction of block, stone and brick buildings, with large-pointed installation, as well as for the base under the house of rapidly assembling wood.

There are also non-standard varieties of slabs of overlapping, for example, tent - often cast for overlapping around the size of the room in the form of a dome or a pyramidal form. However, their cost can significantly exceed the cost. standard platesand the dimensions depend on the architectural project.

The main advantages of building materials

1. Thanks to the system of intersecting beams and reinforcement with concrete filling, such reinforced concrete structures are able to withstand a fairly impressive load.

2. Today, plates are made from high-strength concrete according to the latest technologies - to obtain high-quality material. For example, they found widespread use in the seismic activity zone.

3. Hollow building material has excellent thermal insulation properties, it is frosty and promotes fire safety.

4. In terms of competent installation, standardized building materials provides waterproof in the building and performs other insulating tasks. For example, prevents penetration, noise, steam, gas to other parts of the structure.

5. Overlapping plates are able to provide absolute horizontal surfaces, especially with competent supports.

6. The material is distinguished by strength and durability, does not require additional care and facilitates finishing with finishing coatings, becoming the basis.

7. Some void varieties contain porous materials for additional frost resistance or countering temperature drops.

Varieties of slabs of overlapping

Universal building materials produced different sizeBut all of them have a common - their form. Plates are produced 2 types - full and hollow.

1. The full-scale monolithic slab overlap does not have internal voids are used on lower floors and in the construction of production areas. This building material has 3 subspecies:

• bearless plates, monolithic smooth material for ceilings;
• cable slabs that resemble a cellular grid of identical beams with a small layer of concrete used for industrial construction;
• the plates of overlapping slabs are maintained the greatest load, for example, at the base with high construction.

The manufacture of the monolithic slab overlap is a fairly simple process that is often made at the place of installation. The frame of the reinforcement is loaded into the horizontal formwork, after which concrete is poured. The dimensions of such slabs can vary.

Basic technical parameters and product marking

An important factor for settlement in architecture and installation compliance with the requirements for the standardization of the outlet stoves. They must comply with GOST not only on dimensions, but also by strength, crack resistance, rigidity and other parameters to withstand the project load.

According to GOST slab overlap, dimensions have different, but necessarily have their own standards. It is convenient for designing structures and installation.

The letters - the product brand, 2 digits - length measured in decimeters, the following numbers - widths also in decimeters, the last digit in the marking indicates its overall calculation load, without taking into account the weight of the slab of the overlap, that is, its carrying capacity in the design of the overlaps. For example, when labeling PC 53-12-8T, this means that the slab is round-stand, that is, parallel holes in it have cylindrical shape. Its dimensions, length and width are indicated in decimeters, and T - means that it is made of dense concrete M200.

The standard thickness of the slab of the overlap of reinforced concrete is about 220 mm, but there is a lightweight variant, by 16 mm. This building material also has an important indicator - the third category of crack resistance, that is, the occurrence of cracks are permissible in their operation, but this cannot affect the main carrying characteristics of the structure. Some plates are manufactured with additional reinforcement of ATV class. It is believed that the greatest bearing ability - monolithic overlapsWhen pouring these plates, professional flooring of the brand N.

Marking also assumes other characteristics:

• 1PK - multi-consist by 220 mm, diameter of rounded voids of 159 mm;
• 2PCs - multi-consisting plates by 220 mm, diameter of rounded voids 140 mm;
• 1P - plate 1-layer solid, release by 120 mm;
• 2P - a solid stove for 160 mm;
• PB - multiplass plate forming without formwork by 220 mm.

When labeling 1P in millimeters standard dimensions For plates of overlapping:

• 3000x4800, 3000x5400, 3000x6000 and 3000x6600;
• 3600x4800, 3600x5400, 3600x6000 and 3600x6600.

When labeling 2P in millimeters, standard dimensions for plates of overlapping:

• 2400x6000,
• 3000x4800, 3000x 5400, 3000x 6000;
• 3600x2400, 3600x3000, 3600x3600, 3600x4800, 3600x5400 and 3600x6000;
• 6000x1200, 6000x2400, 6000x3000 tons 6000x3600.

Such options in size enable the most accurate fit on the individual planning objects of any configuration. Voids can have different shape And the interval between them.

Features of hollow slabs overlapping and marking

The flood plate is empty has inside parallel holes, round, oval or square shape. In essence, most voids have a cylindrical shape. There are plates reinforced and careless. Although fittings and weight products, they have the greatest margin of safety, therefore are used at the bottom of the structures.

Each marking plate of the overlap speaks not only about its main characteristics, but takes into account the features for choice in a particular place of installation.

• PB - plate with rounded voids of 159 mm in diameter, is cut by a laser of any length during continuous molding. Standard: Length 6-12 m, width 1, 1.2 and 1.8 m, thickness 260 mm. Installed on both ends on the wall;
• GHG - stove with oval voids for mounting on both ends, standard thickness 260 mm;
• 1PK - plate with rounded voids with a diameter of 159 mm, thickness 220 mm, mounting on both ends;
• 2pk - plate with rounded voids of smaller diameter, 140 mm, standard thickness 260 mm, installation of 2 end;
• 2Pt - plate with voids of diameter 140 mm, but thickness is 220 mm, mounting with a support for 3 sides;
• 2PKK - stove with the same parameters (220 mm 140 mm), support for 4 walls;

• 3pk - plate with a thickness of 220 mm with rounded voids of 127 mm, support for 2 end;
• 3Pt - plate with the same parameters and support for 3 sides, where 2 end and one open is long;
• 3PKK - plate with emptiness 127 mm, thickness 220 mm, mounting with a support of 4 sides;
• 4PK - plate with emptiness with a diameter of 159 mm, 260 mm thick, for installation of 2nd ends;
• 5PK - stove with a thickness of 260 mm with holes 180 mm, installation with a support of both ends;
• 6PK - plate with rounded voids 203 mm, thickness of 300 mm, support for 2nd ends;
• 7PCs - plate thickness 160 mm with a diameter of emptiness 114 mm, installation with a support for 2 end;
• 1Pt - the stove with the same parameters as the previous one, but the walls are laid on the 3rd sides;
• 1PKK - stove with the same parameters, installation of 4 sides.

By the type of reinforcement, HV plates have such varieties:

• a concrete brand B40 and single-barred reinforcement is used in the NV plates;
• in the NVK - concrete of the same brand and reinforcement of two-round;
• in NVKu - reinforcement two-round, applied concrete brand B45.

Basic technical parameters of floor slabs

1. The concrete is used in the concrete, which has an indicator for compressing for strength B22.5.

2. Brand of concrete for plates used in conditions of harsh climate - F200, taking into account the reserve of frost resistance.

3. Concrete density indicator - about 2000-2400 kg / m3.

4. The strength of the concrete must respond to parameters of 261.9 kg / cm2.

5. Brand concrete for laying plates at the bottom, taking into account moisture resistance - W4.

6. The length of the ceiling slabs varies according to the standard - in the range of 2.1-9.2 m.

7. Product width standards are about 1m, 1.2 m, 1.5m, 1.8m.

8. HB and PB plates also make a width of 0.55 m.

Plates of overlapping as a foundation

Domestic house-building is widely used plate variety Stacking foundation. For this, monolithic, ribbed and empty bribes are suitable, it all depends on the floor and the total load of the structure. Such a foundation has a slight pressure on the ground, so the building easier to transfers seasonal fluctuations in the soil. Installation of such a foundation is the least laborious and suitable for fast mount Houses of the national team design - for season 1.

Before starting the laying, they align the pit and dumbfound the bottom of rubble, gravel or sand under the laying of the slabs of the overlap. In low-rise building foundation with hollow plates It will be reliable, it will cost cheaper, such plates give better sound and thermal insulation. The seams between the plates need to overlap so that the national framework of the foundation is most common. For such a design, slabs with a thickness of 100-120 mm are suitable, and for a more thorough structure, the plates are needed for 200-250 mm with rigidity ribs. In their voids, it is also very convenient to lay various communications.

Storage and transportation plates of overlapping

From the correctness of the storage and transportation of the slabs of the overlapping will further depend on the quality of the construction, respectively, the safety of the entire object. The plates are transported only by special transport, guaranteeing their integrity, and it provides competent unloading and storage. The plates of the same size are stacked by stacks, carefully lays down each other, but not higher than 2.5 m. It is advisable to lay the gaskets about 30 mm between them. Stacks can be covered with a protective film - from the destructive effect of precipitation and aggressive external environment. For years stored in the open air and with significant temperature drops of the ceiling plate should not, they repense and lose properties.

Features of laying slabs of overlapping

Any kinds of progress are sufficiently heavy, and the slabs of overlappings. But this is their only drawback when installing, which itself is quite convenient. The main requirement when laying is a horizontal and flat plane of the support that the plates will be mounted. When the wall foam concrete, brick or laid out of a crispy shell, then an additional concrete armoomas needs.

Another point is the area of \u200b\u200blaying plates with laying when laying. Best optionWhen it is at least 120 mm with each end side. The solution that will be laid under the plates is used in semi-dry form. In the use of flood slabs with voids, it is important to comply with such conditions where the temperature regime and general level Humidity will not be higher than the norm. Anchoring, or a bunch of plates, is made of welding - for connecting the plates with each other with a rod in 12 mm. Open empties with high-quality laying should be covered around the edges mineral insulation and closed cement mixture. It protects plates in frosty time freezing.

If you at least once come across the construction process or repaired an apartment, then you should be known what void floodplain plates represent. Their value is difficult to overestimate. Features of the design, its main characteristics and labeling are taken into account during the work. These knowledge allow you to determine what the limit of useful and decorative loads can withstand the stove.

Sizes and weight

The size and type of product affect its final price. The length described plates may be equal to the limit of 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, whereas their width usually reaches 1.5 m maximum. The minimum value is 1.2 m. Getting acquainted with the size of hollow plates, you can understand that their thickness remains unchanged and is equal to 22 cm. Given the impressive weight of such designs, a mounting crane is usually used to install them, its power should be 5 tons.

Types of load on reinforced concrete construction

Any overlap in the structure has three parts, among them:

• top;
• lower;
• structural.

The first is located where the residential floor is located at the top. This includes flooring, insulating materials and screeds. The lower part is the surface non-residential premises. It can be attributed to the suspension elements and ceiling finishes. As for the structural part, it combines the above described and holds them in the air.

Wetting plates of overlappings perform the role of the structural part. Permanent static load have on it decoration Materialsused in the design of the ceiling and floor. Under this implies elements suspended to the overlap and installed on it from above, namely:

• boxing pears;
• dropped ceilings;
• chandeliers;
• partitions;
• baths.

In addition, you can also select dynamic load. It is provided by the objects moving on the surface. It should take into account not only a mass of human, but also pets, which today are quite exotic (tigers, lynx, etc.).

Distributed and point loads

The above-mentioned loads of loads may be supplied to the wetting plates. Point, for example, is a boxing pear of impressive sizes suspended to the ceiling. Concerning suspended system, it is a frame at an equal distance interval interacts with suspensions and has a distributed load.

These two varieties of load can effectively affect. IN this case Calculation will be complicated. If you install a bath, which accommodates 500 liters, then take into account two types of load. Distributed has a filled container on the surface of the support between the points of contact. There is also a point load, which turns out to be each leg separately.

Calculation of permissible loads

The load on the hollow plates can be calculated. These manipulations are carried out in order to find out how much the product can endure. After it is necessary to determine what the overlap will suffer. This includes partitions, materials based on insulating layers, parquet coatings and cement screeds.

The overall weight of the load must be divided into the number of plates. Roof supports and bearing supports should be located along the ends. The internal parts are reinforced so that the load turns out to be on the ends. The central part of the plate is not able to take the weight of serious structures. This is true even if there are capital walls or support columns from below. Now you can make a load calculation on the hollow plate. To do this, you need to know its weight. If you take a product with marking PC-60-15-8, then it can be argued that its weight is 2850 kg. It is made according to state standards 9561-91.

First of all, it is necessary to determine what the area of \u200b\u200bthe carrier surface of the product is 9 m 2. For this 6 must be multiplied by 1.5. Now you can find out how many load kilograms can make this surface. For which the area must be multiplied by a permissible load on one square meter. As a result, it will be possible to get 7,200 kg (9 m 2 multiply by 800 kg per m 2). Hence the mass of the slab itself, and then it will be possible to get 4350 kg.

After you need to calculate how many kilograms will add insulation of floors, floor coverings and screed. Usually, work is trying to use such a volume of solution and thermal insulation so that the materials together do not weighed more than 150 kg / m 2. At 9 m 2 surfaces, the hollow plate will incur 1350 kg. This value can be obtained by multiplying by 150 kg / m 2. This number should be deducted from the previously obtained numbers (4350 kg). That in the end will allow you to get 3000 kg. Recalling this value to one square meter, you will receive 333 kg / m 2.

According to sanitary standards and rules, the weight of 150 kg / m 2 should be assigned to static and dynamic loads. The remaining 183 kg / m 2 can be used to install decorative elements and partitions. If the weight of the latter exceeds the calculated value, it is recommended to prefer a more lung floor covering.

State Standards and Technical Requirements

For large-pointed buildings of various purposes, wear plates are necessarily used. They are manufactured on the above state standard and may have the following materials at the heart:

• light concrete;
• silicate concrete;
• heavy concrete.

The manufacturing technology providing for the availability of voids provides designs excellent sound insulation properties and low weight. They are ready to serve for a long time and possess good strength characteristicswhich are due to the use of steel ropes and fittings.

When installing such products are located on carrier structures. Round voids can have a diameter of 159 mm. The dimensions of the hollow slabs are one of the factors according to which product classifications are conducted. 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. The density is equal to the limit of 2000 to 2400 kg / m 3. In state standards, the brand of concrete, taking into account the frost resistance, is prescribed, it looks like this: F200. The hollow slabs (GOST 9561-91) are made of concrete with strength in the range of 261.9 kg / cm 2.

Brands of hollow plates

Reinforced concrete products, molded in the plant, are subject to labeling. It is encoded information. Plates are denoted by two PC capabilities. This abbreviation stands next to the number that denotes the length of the product in decimeters. Next comes the numbers denoting the width. The last figure indicates what weight in kilograms is withstanding 1 dm 2, taking into account its own mass.

For example, a reinforced concrete hollow plate of PC 12-10-8 is a product with a length of 12 dm, which is 1.18 m. The width of such a plate is 0.99 m (approximately 10 dm). The maximum load on 1 dm 2 is 8 kg, which is 800 kg per square meter. In general, this value is equally almost for all hollow plates. As an exclusion, products are capable of withstanding up to 1250 kg per square meter. Such plates you can learn on the labeling, at the end of which the numbers are 10 or 12.5.

Cost plates

Inter-storey hollow plates are manufactured using conventional or pre-hard fittings. Panels, in addition to the bearing ability, must also correspond to the requirements of sound insulation. For this, the product is supplied with holes that may have a round or other section. Such structures refer to the third category of crack resistance.

In addition to these characteristics, you can also be interested in the cost. Pay for the hollow slab, the weight of which is 0.49 tons, you will need to be 3469 rubles. In this case, we are talking about the product with the following dimensions: 1680x990x220 mm. If the weight of the plate increases to 0.65 tons, and the dimensions become equal to 1680x1490x220 mm, then you will need to pay 4351 rubles. The thickness of the hollow slab remains unchanged, which cannot be said about the rest of the parameters. For example, purchase a product with dimensions equal to 1880x990x220 mm, you can 3473 rubles.

For reference

If the slab overlap is made at the factory, then in the process of this state standards. They guarantee high quality products and matching the hardening time and temperature regimes. The full-scale type of plate is distinguished by impressive weight, respectively, high cost. This explains the fact that such products are most commonly used when erecting important buildings.

Finally

The slabs of the overlap found their popularity and gained widespread in the construction of residential buildings and are smaller than the weight compared to full-scale plates, and they are cheaper. But in matters of reliability and strength they are not inferior. The location of emptiness and their number does not affect the carrier properties of the plate. In addition, they allow you to achieve higher sound and thermal insulation properties of the structure.

But no matter how lighters they were considered, when they were installed, it is not necessary to do without the corresponding lifting equipment. This allows you to increase the accuracy of the installation and complete the construction in more short time. These products are good as the fact that they are manufactured in the plant, which means quality control undergo.

Plates of overlapping - Wednesday about this type of reinforced concrete products will we are talking In this article.

Everything modern designs Buildings in their production process are divided into two large groups:

• buildings from monolithic concrete
• buildings and facilities from the precast concrete

Comparison of slabs of overlapping and monolith

Each of these groups have advantages and disadvantages. The monolithic structures of buildings and structures have the main and indisputable advantage - you can do almost any imaginable and unthinkable forms, embodying the creative visions of the architect. Another equally important advantage is that monolithic structures more durable due to the fact that steel frame From the reinforcement passes through all the structures of the building in one whole. In this case, the amount of concrete and the thickness of the carrier supports can be reduced, which can also affect the budget in the positive side.

At buildings from the precast concrete, their advantages. First of all, these are the deadlines for the construction of the construction - all parts of the future building are brought to the construction site in finished video, and the monolith is gaining strength after 28 days, although in large construction facilities The next floor is already erected after 1.5-2 weeks, after filling the previous floor. Plus, thanks to a standardized and automated manufacturing process, all products receive quality standards in the established regulatory limits.

It is also worth noting that the costs of the work of people and techniques in the construction of buildings from the precast concrete is significantly lower. For example, if when pouring the monolith of the slab of the overlap at the calculated value of concrete 3000 rubles per 1 cube concrete, the work of the builders will cost about 3 thousand rubles per 1 cubic concrete cube, the cost of mating or welding of the reinforcement frame, installation of formwork and fill concrete. Total price is about 6 thousand rubles per 1 cube of the finished product.

With floor area at 100 square meters The fill of the ceiling slab with a thickness of 20 cm will cost 100 x 0.2 x 6000 \u003d 120,000 thousand rubles. But do not forget about metallic frame. Take for the calculation of the reinforcement 10 mm, the grid (cell paging) is 20cm. For our volume, about 100 fuses of fittings are needed (whip length is 11.7 meters), it is for one grid level, for two, respectively 200. This is about 1.5 tons of metal, with a metal of 32 thousand per ton, the price is 48 thousand rubles. You can also throw 2 thousand on knitting wire and corks (lining so that the reinforcement grid does not touch the formwork - the concrete after the fill must protect the steel reinforcement from the action ambient). Total 170 thousand rubles.

At the same time, for overlapping this space, the empty slabs of the overlap will be required 12 plate overlap. The overall dimensions of the slab for the calculation were taken by 6300 x 1500 (PC overlap plates 63-15), it turns out that 11 plates need, but it usually happens that the plates are stacked in two equal rows (for example, if the house is 12m x 8.5m) , and the discovering remains of the plates are usually sprinkled with a diamond circle for a grinder or beaten by scrap in the direction of the longitudinal opening of the plate. Because it is not always possible to make a house on the project, with the size connected under the sizes of the plates. Although if we are talking about a lot floor constructionIn this case, all sizes are consistent with the typical sizes of factory reinforced concrete products.

So, 12 plates, the cost of the PC-63-15 plate is about 10,000 thousand rubles, delivery in the city is approximately 4.5 thousand for the flight, in the body a maximum of 4 plates (we are talking about new and non-stoves). 3 flights are 13.5 thousand rubles Plus the cost of plates of 120 thousand rubles.

Laying 12 plates is a maximum of 3 hours of operation, the cost of renting a crane 1.5 thousand rubles per hour, at least 3 hours and 4.5 thousand hours. Payments for the work on the slab to the maximum of 500 rubles a plate (although 2 500 rubles per day at a per day can work wonders under sensitive guidance). Total 6 thousand. A total of 144 thousand rubles. This example shows a difference of 26 thousand rubles, although for actual case It is necessary to calculate separately. But the small savings on the finished reinforced concrete will always be able to compare the good work flooding monolith and new reinforced concrete structures.

Spheres of flooring slabs

Plates of overlapping got very wide applicationAnd this is probably the most used type of reinforced concrete products. They are used to overlap the spans up to 9 meters, although the most common plate type is 6300mm long plates. Basements ground floors, inter-storey overlap - Data stoves are used everywhere. In many storey construction, the slabs were also widespread, especially in soviet period where the speed of construction was important - it was necessary to provide housing a large number of citizens.

Currently, overlapping slabs are also often used with country cottages.

In the industrial construction of plant workshops, the P-shaped plates are most often used (if you look in the section) plates that are marked as PCW plates. These are lightweight structures created to create roofs of production buildings and structures that are unable to carry such loads as vigilant, especially for production equipment. Their main purpose is the roof of the building.

The most common size is 6000 x 3000mm. Due to the oversized sizes of these stoves, the trawl is used for transportation - the long platform is attached to the tractor. Also, for transporting oversized cargo, you need to take care of the passage for oversized special transport in the local traffic police, there will be an official resolution and a clear route in order not to upload the main streets of the city.

Laying plates of overlaps

The slabs of the overlap are stacked on the bearing walls of the building. Structurally, they should rely on the carrier wall of at least 12 cm, although with unreliable construction there were cases when builders put a plate with 2 cm, but it is categorically worth to do. Snip accurately indicates a value of 12 cm. The plates are laid dry or per solution, and when laying the slab on a solution it is easier to align it after laying. It is also necessary to observe the technological seam between the plates size 5-20 cm, which is filled with a solution after styling.

Before installing the plate, it must be carefully examined. Not allowed to use slabs that have cracks with a disclosure of more than 1 mm along the entire length of the plate. When using such a ceiling slab under load, the valve can exit concrete and the stove has a chance to break. At the same time, small shrinkage cracks are not more than 1 mm disclosure width are allowed by SNiP.

Technology production slabs overlap

Slabs of overlapping like most other reinforced concrete structures obtained by molding concrete mass. The metal form is a pallet and opening onboard, in one of the sides on the short side of the form there are holes for the input of Poisson - pipes that create emptiness in the stoves. Empty serve to facilitate the mass of the finished slabs and saving concrete.

IN manufacturing workshop The whole process looks like this. The shape rises to the vibrationtol. It turns on the electromagnet and the form sticks to the vibrotol.

In the form of a worker puts a pre-welded bottom reinforcing frame (lower frame from thicker reinforcement). Poissons enter the shape of the form, filling out part of the space. The top reinforcement grid is installed on top. A concrete-layer approaches the tap of the beam, and fills the shape of the plate with a solution.

Also on the crane beam, the form is covered with a metal lid. Vibrotole turns on and begins to vibrate the form so that the concrete is touched. After the cover is removed, and then Poissons leave the shape. In the rammed concrete, empties are formed, and the form further goes on the drying in the opposer chamber, where there is about a day, for the speedy grasp of concrete. Well, a day later, the finished slabs of overlappings are stored in the warehouse site.