RU167575U1 - SEMI-FINISHED PRODUCT FOR MANUFACTURE OF LOADED REINFORCED CONCRETE BEAM - Google Patents

Abstract

The utility model relates to the field of construction, in particular for the manufacture of load-bearing structures of industrial and civil objects, building elements, including flexible structures (crossbars) such as trusses, beams, cantilevers, etc. The technical result is the creation of a semi-finished product for a loaded reinforced concrete beam with high rigidity bending and increased bearing capacity through the use of prestressed composite reinforcement. The technical result is achieved in that the semi-finished product for the manufacture of a loaded reinforced concrete beam contains prestressed composite reinforcement in a concrete shell, while the cross-sectional area of concrete in the area of the location of the reinforcing bars and the cross-sectional area of the reinforcing bars are related by the following ratio: Heavy concrete or expanded clay concrete is used. The section of the semi-finished product may be oval, rectangular or T-shaped. In the latter case, there is a hole on the leg of the T-section. The surface of the semi-finished product can be ribbed, and the rib can be longitudinal, inclined or transverse.

Description

The utility model relates to the field of construction, in particular for the manufacture of load-bearing structures of industrial and civil facilities, building elements, including flexible structures (girders) such as trusses, beams, cantilevers, etc. A semi-finished product is a structure made of prestressed concrete bar reinforcement in high-strength concrete shell.

Reinforced concrete crossbars are known in which longitudinal reinforcing bars are introduced to perceive tensile forces (Baykov V.N., Sigalov E.E. Reinforced concrete structures: General course: Textbook for high schools. - 5th ed. Revised and additional M .: Stroyizdat, 1991.-125-134 p.).

However, the above structures reinforced with metal reinforcement are susceptible to corrosion, have high thermal conductivity and electrical conductivity.

In order to eliminate corrosion and reduce thermal conductivity, some foreign companies (for example, SCHOECK, see patent EP 1860246, ЕВВ 1/00, publ. 12.11.2007) use stainless steel as metal fittings. However, this significantly increases the cost of the design, and the thermal conductivity is reduced insufficiently (the thermal conductivity of stainless steel reinforcement is 4 times lower than that of ordinary steel, but 100 times higher than that of composite reinforcement).

Known composite composite concrete beam (RF patent No. 2490404, E04C Z / 29, publ. 08/20/2013) - prototype. The beam is light weight and not subject to corrosion.

The composite reinforcement used in this beam has certain advantages over metal reinforcement:

- does not corrode;

- does not conduct heat;

- does not conduct current;

- 4 times lighter than metal fittings.

These qualities of composite reinforcement are especially relevant in areas where the listed properties are required: in the enclosing structures of buildings and structures, traverses of high-voltage lines, etc.

However, composite reinforcement has a low modulus of elasticity, so the beam does not have the necessary bending stiffness and cannot serve as a strength element in loaded structures, for example, as a console of balconies of multi-storey buildings.

The technical result is the creation of a semi-finished product for a loaded reinforced concrete beam with high bending stiffness and increased bearing capacity due to the use of prestressed composite reinforcement.

The technical result is achieved by the fact that the semi-finished product for the manufacture of a loaded reinforced concrete beam contains prestressed composite reinforcement in a concrete shell, while the cross-sectional area of concrete in the area of the location of the reinforcing bars and the cross-sectional area of the reinforcing bars are related by the following ratio:

As concrete, heavy concrete or expanded clay concrete was used. The section of the semi-finished product may be oval, rectangular or T-shaped. In the latter case, there is a hole on the leg of the T-section. The surface of the semi-finished product can be made ribbed, and the rib can be longitudinal, inclined or transverse.

The essence of the technical solution is illustrated by drawings.

FIG. 1 - semi-finished product for reinforced concrete beams.

FIG. 2 - semi-finished product for reinforced concrete beams of oval section.

FIG. 3 - a semi-finished product for a reinforced concrete beam of a T-shaped section.

FIG. 4 - a semi-finished product for a reinforced concrete beam, mounted in a support as a beam.

FIG. 5 - installation of the semi-finished product of FIG. 2 in the balcony console.

The difficulty of using composite reinforcement as a loaded element lies in its low tensile modulus compared to steel reinforcement: about 4 times less. To achieve the same deflection value as in the case of steel reinforcement, the cross-sectional area of the composite reinforcement should be 4 times larger. However, the necessary value of the deflection can also be achieved by prestressing the composite reinforcement, even reducing its cross-sectional area. During the construction of buildings (for example, monolithic), the manufacture of structural elements is carried out directly at the construction site by pouring concrete reinforcement of metal reinforcement.

However, the process of prestressing reinforcement, including composite, is carried out only in the factory with the production of a semi-finished product, which, according to this utility model, is used as reinforcement to produce a loaded concrete beam (for example, a balcony console) by pouring concrete at a construction site.

The semi-finished product of the loaded concrete beam is made of a hardening mixture of cement and filler (natural, for example, granite crushed stone, and artificial, for example, expanded clay) and reinforced with prestressed rods of composite material (fiberglass, basalt plastic, aramidoplastics, carbon fiber).

In FIG. 1 shows a semi-finished product for a reinforced concrete beam reinforced with prestressed rods 1 of composite material (for example, fiberglass, basalt plastic, aramidoplastics, carbon fiber). Both heavy concrete with natural fillers (crushed stone) and light concrete with artificial fillers (for example, expanded clay) can be used. The one and the other concrete is indicated by 2 in the figures. This semi-finished product can be used for the manufacture of crossbars.

To obtain a quality product, it is necessary to use high grades of concrete. The brand of concrete is determined by the quality of the cement mixture. The semi-finished product has a ribbed surface (ribs are indicated by the number 3), and the ribs can be inclined, transverse or longitudinal. Such a surface provides better adhesion to building concrete.

The semi-finished product of FIG. 1 can be used instead of metal reinforcement for the manufacture of concrete structures that are operated in a corrosive environment, serve as reinforcement in the installation of ceilings, underground car parks, garages, port facilities, chemical warehouses, etc.

In FIG. 2 shows a semi-finished product for an oval-shaped reinforced concrete beam reinforced with prestressed rods 1 of composite material arranged in two rows. In the lower row of the semi-finished product are rods of smaller diameter than in the upper row (for example, with a diameter of 10-14 mm and 28-35 mm, respectively). Expanded clay is used as concrete 2. Ribs 3 are made longitudinal. This semi-finished product can be used in the manufacture of a balcony console for houses with hollow core slabs. The size of the oval corresponds to the size of the hole in the hollow core slab, which allows you to pinch the end of the semi-finished product in the hole of the hollow core slab.

In FIG. 3 shows a semi-finished product for a reinforced concrete beam of a T-section made of lightweight expanded clay concrete 2, reinforced with prestressed rods 1 of composite material. In the lower part of the semi-finished product there are holes 4 for accommodating transverse reinforcement (not shown). This semi-finished product is intended to serve as a balcony console in monolithic buildings.

In FIG. 2 and FIG. 3 shows semi-finished products for balcony consoles. The use of these products allows you to solve the problem of thermal protection of balcony consoles, reduce heat loss. This solution is much more energy-efficient than a technical solution using metal (stainless steel) as a reinforcement.

In FIG. 4 shows a semi-finished product for a reinforced concrete beam mounted in a support 5 as a traverse. The semi-finished product is poured with concrete in the body of the support (for example, power lines).

In FIG. 5 shows the installation of the semi-finished product of FIG. 2 in the balcony console. The semi-finished product is located in the wall of the house, perpendicular to it, while one end is pinched in the hole of the hollow core slab 6, and the other end is a console protruding from the wall of the house through the insulation layer 7, on which the balcony slab 8 is formed.

The cross-sectional area of concrete in the area of the location of the reinforcing bars and the cross-sectional area of the reinforcing bars in the above examples of semi-finished products are related by the following ratio.

where M is the concrete grade (MPa);

S6 - sectional area of concrete (cm ² );

In - tension force of reinforcement (MPa);

Sa is the cross section of the reinforcement (cm ² ).

This ratio is determined by the fact that, with a lower value, self-crushing of the concrete structure is possible under conditions of stress relief from reinforcing bars during molding. With an increase in this value, an increase in the weight of the semi-finished product occurs, which entails the need to use hoisting mechanisms.

As follows from the formula, increasing the grade of concrete mix allows to reduce its cross-sectional area.

Semi-finished product for reinforced concrete beam can be made in two ways.

The first way is by molding. They take the mold, place the composite reinforcement in it, preload it (for example, using anchors according to the RF patent for utility model No. 109172, E04C 5/12, published on 10/10/2011), fill the mold with concrete and compact it (for example, with a vibrator).

The second method is formless molding. The technological process begins by cleaning the molding track with a specialized machine and spraying it with a lubricant in the form of a thin air dispersion.

After that, using a machine for laying out rods wound around a drum, they are unwound and laid out on a track. After laying out the required length of the rods, they are tensioned using an anchor grip.

The ready-mixed concrete is fed into the storage hopper of the forming machine using a concrete supply tank. Includes traction winch and vibrators. During the continuous process of forming the track, the concrete mixture is timely supplied to the storage hopper.

The track with the tape of the molded product is covered with a special covering material using a trolley to lay out the protective coating and left for the duration of the heat treatment process. After the concrete reaches the gearing strength, the covering material is removed, then the semi-finished product for the reinforced concrete beam is marked into pieces of the design length for subsequent cutting.

Semi-finished product cutting is carried out by a special machine for transverse cutting, equipped with a high-strength cutting disc with diamond coating.

The tests carried out showed the operability of the structure and the achievement of the claimed technical result: a semi-finished product was created for a loaded reinforced concrete beam with high bending stiffness and increased bearing capacity through the use of prestressed composite reinforcement.

Claims (9)

1. A semi-finished product for the manufacture of a loaded reinforced concrete beam, containing prestressed composite reinforcement in a concrete shell, the cross-sectional area of concrete in the area of the location of the reinforcing bars and the cross-sectional area of the reinforcing bars are related by the following ratio:

where M is the concrete grade (MPa); Sб - concrete cross-sectional area (cm ² ); In - tension force of reinforcement (MPa); Sa is the cross section of the reinforcement (cm ² ). 2. The semi-finished product according to claim 1, characterized in that heavy concrete is used as concrete. 3. The semi-finished product according to claim 1, characterized in that expanded clay is used as concrete. 4. The semi-finished product according to claim 1, characterized in that its cross section is oval or rectangular. 5. The semi-finished product according to claim 1, characterized in that its cross section is T-shaped. 6. The semi-finished product according to claim 5, characterized in that there is an opening on the leg of the T-shaped section. 7. The semi-finished product according to claim 2 or 3, characterized in that the surface of the semi-finished product is ribbed.

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