Support plate 2. Reinforced concrete fence. Product quality control

Floor slabs for trays PO 2 – these are popular reinforced concrete products, without which it is difficult to imagine the construction of various engineering structures. Channels and tunnels using such elements are distinguished by strength, reliability and durability.PO 2 - a rectangular solid flat slab that is used to cover canals and other structures. The use of these products has a practical justification for the construction of heating mains and thermal chambers.

The main design feature is the presence of a hole with a standard diameter of 700 mm. This opening is used to access the main network nodes. It is very important to get a high-quality structure that requires a minimum of investment and further repairs.Floor slabs for trays PO 2 – these are exactly the elements. The elements are not ordinary and cannot be used to cover buildings.

1. Variants of marking writing.

Products for covering trays typePO 2 marked according toSeries 3.006.1-2.87 . Allowed to produce different variants writing the notation. Let us indicate the main ones (all methods are not an error):

1. PO 2;

2. PO-2;

3. PO 2-1.

2. Main scope of application.

Apply PO 2 plates for covering trays and beams of chambers. Due to the presence of a hole, and there can be two of them, stipulated by the terms of the technical design, the product has the ability to arrange “difficult” sections of the route. Install on top of plates with holes concrete rings, which are used as shafts for access to the main nodal points of laid communications or networks.

The channel, which is built from reinforced concrete slabs and other elements, must be airtight and durable in order to fully protect the networks. All joints and seams are sealed cement mortar grades for compressive strength M50, coated with mastic.Floor slabs for trays PO 2 undergo additional hydrophobic treatment, which increases resistance to the action of underground groundwater and other effects of moisture on the channel itself and the communications laid in it.

The depth of the canal structure can reach up to 6 meters, which is why it is so important to choose durable and high-quality reinforced concrete products for the construction of engineering structures. Can be used for above-ground laying of channels or tunnels. The standard size of this product means it can be laid in any direction.

Floor slabs for trays PO 2 mounted using two to four sling loops type UP2-3. S-shaped hooks are attached to them and they are lifted to a height. Subsequently, the loops are cut or bent at the request of the customer. Holes can be made in the products; in this case, installation is carried out using a loopless method. Installed slabs It is very difficult to move along the surface, since they have a significant mass, due to which the products are fixed on the surface of the tray or beam.

3. Product markings and basic meanings.

All slabs PO 2 designate according toSeries 3.006.1-2.87 and indicate the type of product and the main standard size. Markings are applied to the side edge using black paint. Only used leave-in formulations. Additionally, the manufacturer can indicate a special trademark, weight and production date of the product.

Let's look at the basic data on the slab typePO 2 :

1. Length – 1450 .

2. Width – 1500 .

3. Height – 120 .

4. Geometric volume –0,261 .

5. Volume of concrete –0,26 .

6. Weight – 550 .

4. Basic materials and their characteristics.

As source material Forfloor slabs PO 2 Heavy concrete of strength grade B25 is used. They are distinguished by high strength and resistance to action external environment, long service life without repairing products. At the core is steel frame from 10 mm rods. steel class AIII according toGOST 5781-82 , as well as reinforcing bars St5 and St17, mesh type C10, made by resistance spot welding. Reinforcing components are placed in the “working” areas of the slab. All metal elements treated with anti-corrosion compounds.

Floor slab for trays and channels with a hole ( PO 2 ) – a rectangular slab for covering channels, tunnels, thermal chambers made of tray elements at the location of the vertical entrance to the channel. The task of the slab is to overlap the trays at the point where the chamber is formed. For this purpose, the plate design contains one or two holes with a diameter of 700 mm. The floor slabs are placed on the trays and beams of the chambers, and then concrete rings are installed on the slab, which make up the chamber shaft.

Also, the presence of the slab helps maintain tightness and protect underground utility channels from destruction of insulation, soil collapses and moisture ingress.

The shape of the PO 2 slab is rectangular flat plate with one or two holes for subsequent installation of inspection wells.

The floor slab is used both in above-ground and underground channels, as well as those laid under iron and highways. The depth of such channels under the soil layer is from 0.5 to 6 meters. This means that the coating slab must withstand sometimes colossal loads. The material that helps the slab carry vertical temporary and long-term loads is heavy concrete B 25 (M200-300) and high-quality steel reinforcement classes A-I and A-III. Reinforcement of the PO 2 floor slab is made with welded mesh and frames made of rod reinforcement and wire, the frame is laid under protective layer concrete 15-20 mm. The presence of holes should not affect the strength of the product, because its task is to protect communications. Therefore, in places where there are holes, additional reinforcement is installed with separate steel rods and meshes.

Issue 6 This series involves the production of floor slabs with a length of 1450 mm, a width of 1500 mm and a height of 120 mm.

The section thickness of the floor slab is 120 mm. The standard sizes of the slabs are determined by the fact that the trays are overlapped by them both along and across, according to the overlap schemes of the chambers and channel units.

Slabs intended for use under the eroding influence of groundwater are additionally protected from corrosion. For this purpose in concrete mixture special additives are added. Thanks to them, the slab can withstand the effects of aggressive chemical environments for a long time. All slab embedded products also have anti-corrosion treatment.

The weight of the PO 2 channel covering slab varies and is 550 kg. Such a cover is tightly fixed to the channel due to its weight, this prevents the subsequent sliding of the slab on the concrete.

The slabs are installed using a loopless installation method using sling holes. Less common are slabs with mounting loops incorporated into their design.

The covers of the channel trays are characterized by increased frost resistance (F300), this allows the slabs to withstand frequent temperature changes characteristic of middle zone Russia. A high class of water resistance together with high-quality waterproofing guarantees the channel dryness.

After welding the brackets, the seams and slings between the tray elements and floor slabs are sealed with mortar or mastic, and the channel is hydro- and vapor-proofed.

Product marking

The floor slab is conventionally designated by an alphanumeric combination. Designate the type of product, serial number by size and calculated equivalent load in tf/m2. If necessary, the resistance of the slab to aggressive environments is designated by the letter N.

As an example of slab marking, consider (1450x 1500x 200 mm), where:

• PO – channel floor slab with a hole;
• Number – standard size of the product;

Markings, as well as the date of manufacture and weight of the product are located on the end face of the plate.

On acceptance tests control the following parameters of floor slabs:

• concrete strength (class of concrete in terms of compressive strength, tempering strength);
• compliance of reinforcement and embedded products;
• strength of welded joints;
• thickness of the protective layer of concrete to the reinforcement;
• integrity and purity ventilation ducts;
• accuracy overall dimensions;

The batch of channel covering slabs must be accompanied by technical certificate , in which they indicate:

• grade of concrete in terms of strength and its average density;
• tempering strength of concrete and actual tempering density of concrete;
• concrete grade for frost resistance;
• concrete grade for water resistance;
• date of manufacture of slabs PO 2.
• number of reinforced concrete products;
• indication of compliance with the state standard.

Transportation and storage

Coating slabs, unlike most reinforced concrete products, are transported in the “edge” position. Stacked concrete slabs should not be higher than 2.5 meters. Under the bottom row of slabs, on a leveled base, a wooden pad with a thickness of at least 3 cm is placed. The products are transported by various means of transport, securely fastened, using gaskets and pads at the locations of the lifting loops.

Reinforced concrete fence slab ( PO-2 ) - durable and durable design, able to easily withstand long-term exposure to moisture and any aggressive environment. Concrete slab fences are a guarantee of safety and reliability

A solid concrete fence is the choice of professionals who strive to maximally secure the area adjacent to their objects. After all, solid concrete is a serious obstacle both physically and psychologically.

The fence wall made of slabs reaches a height of up to 2.9 m, and due to the ability to place additional fences on the top of the slab (for example, barbed wire) such a fence becomes an almost insurmountable obstacle for intruders. Civil structures and construction sites, as a rule, are fenced with reinforced concrete fences 1.2 and 2 meters high. This height allows neither people nor animals to enter the territory of the facility, and also reliably hides the space from prying eyes.

Solid fences of the PO.2 series are used, as a rule, on industrial enterprises to avoid theft and in medical institutions to protect the peace of patients.

A fence made of slabs is also a kind of protection from wind, debris and extraneous sounds, so the use reinforced concrete slabs justified in residential areas.

But despite this, concrete fences are still security structures, therefore, sensitive enterprises and specially protected facilities, warehouses cannot do without them - the height of the concrete fence slab there is 2.25 meters. Corresponding wickets and gates have been developed for reinforced concrete fences, but the versatility of the products allows the use of any other entrance structures.

Making slabs using vibration pressing or vibration casting from good cement and quality sand, make it possible to give durability to the slabs with high strength.

The slab is used in conjunction with a glass-type foundation (FO), which is buried in the ground, giving the slab greater stability. Foundations and slabs are available for use even on heaving and bulk soils, provided that a sand cushion is used under the base reinforced concrete fence. Anti-corrosion protection of fencing elements buried in the ground is necessary, despite the high strength of heavy concrete grades M200 used for the manufacture of slabs. The frost resistance of such concrete is at least 50 freeze-thaw cycles. This helps the concrete not to collapse long years, despite the unstoppable change of seasons. The water resistance of the slab is at least W4, allowing it to withstand prolonged exposure to moisture and soil connections.

To strengthen the fence slabs, they are reinforced with steel of class A-III and BP-I, welded into frames. Metal carcass, pre-processed anti-corrosion protection, covers a solid layer of concrete. For ease of lifting and proper installation, the slabs are equipped with sling loops.

A wide range of fence slabs allows you to complete any facility various areas construction. Design drawings and standards for the production of fence slabs are contained in Series IZH 31-77. . Issue 1 of this series involves the production of a PO-2 slab with a length of 2500 mm. The significant thickness of the slabs (150 mm) reliably protects the territory from various extraneous sounds, dust and mechanical damage. It is possible to install barbed wire and lighting fixtures for added security.

Concrete fences, as a rule, differ high quality concrete surface. In most cases, various corrugations or patterns are applied to the slabs to distribute wind loads and make gray concrete less boring. Sometimes the relief of fence slabs is deliberately made very voluminous in order to make it impossible to climb along it.

Such a fence cannot be moved without special equipment and the wind load, which the slab can easily withstand even in a windy area. Also on the shoulder of the slab there is a concentrated load of 100 kgf/rm. To confirm quality fence slabs Each brand is tested by the manufacturer until complete destruction.

The large mass of the slab - 1420 kg - does not allow it to be moved by either wind, moisture or a person. Lifting of such massive concrete panels is carried out only with the help of a crane with a uniform load on all steel mounting loops.

Product marking

Symbol fence slab consists of a designation of the type of structure and its standard size.

As an example of marking, consider slab PO.2 (2500x 150x 3000 mm), where:

• P – fence slab;
• Number – standard size of the product;

Markings, as well as the date of manufacture of the product and its weight are applied to the end face of each product.

Product installation

In addition to slabs, prefabricated enclosing structures consist of glass foundations. Various design features slabs allow you to connect them to form a continuous fence wall. As a rule, fence slabs of the IZH 31-77 series have basement part and is connected to the pillars by welding connecting elements;

Product quality control

The fence, as an external enclosing structure, must meet high requirements appearance. On a surface concrete slab Sinkholes and concrete overhangs of more than 3 mm are unacceptable. Cracks more than 0.3 mm wide and any exposed reinforcement are considered defects. A large number of cracks and cavities lead to rapid crumbling of the structure, the formation of holes and blurring on the surface of the product, which significantly reduces the protective function.

Structures made from concrete fence slabs are usually distinguished by the quality and smoothness of the concrete surface. The smooth concrete surface allows the use of original design solutions when painting the slab, turning the fence into an addition to the style of the building.

During the procedure batch acceptance slabs, the strength of concrete, the compliance of reinforcement products and mounting loops, the strength of welded joints, the accuracy of overall dimensions, the thickness of the protective layer of concrete to the reinforcement, the presence and width of possible cracks are checked.

Quality concrete surfaces and the compliance of the mounting loops is checked by inspecting each product. The quality of reinforced concrete fence slabs is certified by a technical passport accompanying each batch. It informs the consumer about the number of reinforced concrete products in the batch, the date of manufacture of the batch, the mass of the product, and also provides the release strength of the concrete and the grade of concrete for frost resistance and water resistance.

Transportation and storage

Fence slabs, like others reinforced concrete slabs, stored horizontally in stacks. It is important to avoid overloading in a stack of slabs, so you should not stack more than eight panels on top of each other. Wooden spacers are placed between the slabs strictly on the same vertical. It is also possible to store fence panels in vertical position, then the slabs can be laid in cassettes in any quantity.

During the installation of fence slabs, vertical supports are used to prevent the slabs from tipping over before the foundations are grouted and backfilled.