Reinforced concrete non-pressure pipes are used for the construction of gravity drainage systems: sewerage, drainage, drainage. They are considered the most economical and reliable material. Consider further the features of non-pressure pipes.
Nuances of choice
The inner surface of non-pressure pipes should have a slight roughness. The lower its indicator, the less likely the formation of plaque and clogging.
When choosing non-pressure pipes, special attention should be paid to resistance to abrasive wear. In addition, it is important to take into account the parameters of thermal conductivity, shape recovery, rigidity, maintainability.
Classification
It should be said that reinforced concrete pipes are generally produced in different types. The criterion for classification is the purpose of products. On this basis, pipes are distinguished:
- Non-pressure (sewer, for example). They are used for the construction of highways for the transport of liquids by gravity. The cross section of the flows must be 5% smaller than the size of the pipes.
- Pressure concrete. They are used for the construction of highways through which liquid is transported under significantpressure.
- Screed concrete. These products are widened at one end and narrowed at the other.
- Free-flow socket. Pipes of this type are resistant to corrosion, durable. As practice shows, the quality of the inner surface is maintained throughout the entire operational period. Fluid moves by gravity through these pipes.
Concrete is considered a versatile material. That is why it is used in the creation of plumbing systems and other communications. However, unlike other construction works, additional materials and components are used in this case.
Design features
Free-flow pipes can be folded and socketed. The shape of the latter is cylindrical, and the surface of the sleeve part is stepped. Such pipes may be provided with a seal, a sole, as well as a special butt joint.
Seamed pipes differ from raster pipes in the way of connecting individual elements. Various sealants are used to seal products.
Reinforced concrete pipes are a more advanced version of concrete elements. They are more durable, resistant to deformation, compression, stretching, and other destructive processes. The service life can be several decades. The design of these pipes is distinguished by the presence of fittings made of durable steel rods. To increase the strength in the manufacture of products are coated with special compounds.
Terms of Use
Concrete and reinforced concrete pipes are produced bydifferent diameter. Despite their relatively large weight, they are easy to transport. Products can be used in road construction, when laying utilities in residential buildings.
Heavy concrete is used in the manufacture. Non-aggressive liquids move in pipes at temperatures not exceeding 40 degrees and pressures up to 20 atm. When using non-pressure pipes, the conditions are less severe. However, the parameters may change depending on the environmental conditions. As a rule, non-pressure pipes are buried no more than 6 m.
Connection Features
Smooth pipes are connected with couplings. These products are made from M-300 grade concrete.
Pipes and couplings are reinforced with longitudinal spirals and rods. The diameter of the latter is not less than 6 mm, and the gap between them is not more than 200 mm. Reinforced concrete pipes, the wall thickness of which is less than 70 mm, are reinforced with single spirals, and if more than 70 mm - double.
Strength testing
Pipes, as mentioned above, are covered with a special protective layer. Its thickness must be at least 10 mm. Water absorption of products - no more than 8% of the mass of concrete dried to constant weight.
When testing pipes for watertightness, the pressure is set:
- 0.5 atm. – for products with normal strength.
- 1 atm. – for high strength pipes.
To determine the mechanical strength, whole pipes are selected or their elements are cut out with a length of at least 1 m. They are placed in presses on wooden blocks. Alongthe upper cylinders are also installed bars. To evenly distribute pressure, rubber strips or a layer of plaster are laid under them.
Pressure is transmitted through the upper bars at a rate of 500 kg/min. per meter of pipe. The increase in load is carried out with breaks of 2 minutes.
Transportation and storage
Transportation and maintenance of pipes is carried out in accordance with the requirements of State Standards 6482-2011 and 13015.
According to GOSTs, non-pressure pipes are stored and transported in the working position (horizontally). Products must be stacked on inventory pads or other supports made of wood (other material).
Rolling non-pressure pipes is carried out on linings, making sure that they do not rest on the floor or linings with sleeve ends or sockets.
Transportation and storage of products in a vertical position is allowed if their length is up to 2.5-2.5 m. At the same time, their rigid stability must be ensured.
Pipes are stored in warehouses with finished products in containers or stacks. Products must be sorted by brands. The number of rows in a stack depends on the diameter of the pipe passage. This number should not exceed the parameters indicated in the table:
| Diameter (mm) | Number of rows |
| 300-400 | 5 |
| 500-600 | 4 |
| 800-1200 | 3 |
| 1400-2400 | 2 |
| 3000 | 1 |
Pipes in rows should be laid so that the sockets of adjacent rows point in different directions.
Under the bottom row, two linings are laid out on a dense, even base. They must be parallel. Each lining is placed at a distance of 0.2 of the length of the product from the ends. The pads must be of such a design that would prevent the pipes of the lower row from rolling out and their sockets from touching the floor.
When loading, unloading, transportation, measures must be taken to prevent damage to products.
In railway rolling stock or vehicles used to transport pipes, it is necessary to provide saddle pads. Such elements prevent the products from shifting and contact with each other, as well as contact with the bottom of the vehicle.
