Precast reinforced concrete. production technology.

Among the building materials there are quite a few options, which are cut and cast blocks from which you can build load-bearing, self-supporting and partition walls, but the most durable of all is monolithic and precast concrete. All this can be represented in the form of plates, blocks and floors, where the metal frame is filled with concrete, forming a reinforced structure of very high strength. Below we will talk about its production and use, as well as show you the video in this article, as an addition to our topic.

Precast concrete goods

Note. Reinforced concrete is called composite building material, which consists of steel and concrete. It was patented by Joseph Manyier in 1867, and now we are using the SNiP for prefabricated reinforced concrete structures, approved by the USSR State Construction Committee, it is SNiP 2.03.01-84.

Production

• The main specification of precast concrete elements is that, unlike monolithic structures, they are assembled not at construction sites, but in factory workshops, which allows to make products of higher quality. Due to the fact that the assembly of concrete products in the factory is carried out on highly mechanized and almost fully automated equipment, the price of such structures is much lower, because the laboriousness of the process is minimized, therefore, the minimum number of people who need to pay wages is involved.
• In addition to high quality products and savings in human resources, the production of precast concrete is characterized by low costs for the installation of formworksince here they are reusable.

• Considering the GOST for precast concrete structures (GOST 13015.0-83), each ZZHBI is obliged to provide a quality certificate with a list of guidelines for marking concrete, reinforcement and cement, as well as the date of manufacture of the products and their control tests. For such a strength test, control cubes are tested - if the elements have a mass of less than 500 kg, then 6 products out of 250 pieces pass the test, and if the weight is more than 500 kg, then 6 pieces per 100 m³. In addition, tests must be made when changing the composition.
• By types of reinforced concrete structures can be divided into four classes, it is:

1. For the construction of residential and civil buildings;
2. For industrial facilities;
3. For engineering structures;
4. Concrete goods of a various profile.

• Concrete products such as floors, staircases and platforms, panels, wall and foundation concrete blocks and the like will be used for residential and civil buildings..
• For industrial buildings are used reinforced concrete prefabricated columns, piles, column foundations and, of course, slabs and floors. In addition, the assortment of reinforced concrete structures includes tubing, railway sleepers, electrical supports, which are made of heavy concrete with increased strength and a large number of cycles according to the frost resistance parameter.

Equipment for the production of reinforced concrete structures

The whole process of production of reinforced concrete structures consists of at least six basic processes:

1. Production of cement and shortcrust dough;
2. Assembly of metal reinforcement cage;
3. Forming the finished product;
4. Concrete hardening (various accelerators and heating methods are used);
5. Separation of ready-made concrete products from molding formwork;
6. Acquisition of items by labeling.

All these processes are carried out on production lines, which consist of overhead closed conveyors, and they may differ in the arrangement of heat treatment chambers that are under the floor, in close proximity to the molding branch.

The main element of the entire rolling process can be called a vibratory rolling mill, which consists of a circular (endless) steel strip, where the devices for molding and heating the cement-short pastry are located.

With mass production, precast concrete elements are manufactured using a powerful continuous mechanized process - the greatest effect is achieved in the manufacture of typical products such as blocks, floor slabs of beams, supports and tobings.

In cases where the bench method is used, this happens on fixed, specially equipped stands. This technology is fully justified in the manufacture of large-sized and pre-stressed products, as well as in the conditions of the landfill, where the heat treatment of products is carried out in thermoforms or outdoor chambers.

This method provides increased labor costs, as it is difficult to automate the process, and the duration of the entire cycle is usually 1-2 days.

The bench method for the most part is necessary when creating structures in energy construction - these can be spillway and suction pipes, beams, ceilings, sluice chambers, voids in galleries and weirs, turbine chambers and machine rooms. In the stand production, we can note the cassette method, where the formation of concrete goods is carried out in a vertical position in the cassettes, which are detachable group forms.

By and large, the choice of technology is determined by the production capacity of the enterprise, as a decisive factor, as well as the type and size of the product, the possibilities of process automation in this case and the nature of concrete mixes.

There is one more production moment, it is the saving of materials, which, perhaps, is the most painful part of the discussion of any technology for the production of concrete products. If we talk about total calculations, then about 90 kg of standard fuel is consumed for one cubic meter of precast ZHBK. In this regard, at this time, the issue of energy savings in such production is in the search phase.

Construction of prefabricated reinforced concrete structures at home

At home, the installation of precast concrete is most often used to justify the strip foundations, floors (floor, ceiling), as well as for small architectural structures such as garages and other outbuildings on the plot. This can be found quite often and this is not unreasonable - such production significantly saves labor costs, increases the strength of the concrete structure and, therefore, lowers the total cost of construction.

Arrangement of the tape foundation with your own hands from reinforced concrete structural blocks allows you to significantly simplify the entire construction process, and also reduces its cost - the assembly of the tape takes just a few days, including all the excavation work. In fact, the technology is determined by the principle of a brick ordinary masonry, where the elements are fastened together with a cement-sand mortar.

Of course, reinforced concrete prefab house is somewhat more difficult to build, that is, the blocks and floors must comply with the project. This means that the box can not be completely arbitrary, but only taking into account the size of structural materials. However, this installation has an advantage, both in price and speed.

Note. For precast concrete structures, cutting of reinforced concrete with diamond circles and diamond drilling of holes in concrete is performed in the usual way, and the instructions are recorded in the corresponding GOST, Snip and Erin.

Conclusion

Installation of prefabricated reinforced concrete structures is not only possible, but also quite profitable, both in civil and industrial construction. However, the building conditions do not always allow this, therefore, monolithic reinforced concrete structures are currently widely used.