EA032453B1 - Joint between beam elements and column elements made of prefabricated reinforced concrete - Google Patents

Abstract

A joint between beam elements (T) and column elements (C) made of prefabricated reinforced concrete, basically comprises a portion prefabricated with the beam (T), equipped with projecting reinforcement rods (1); a portion prefabricated with the column (C), equipped with projecting reinforcement rods (3); and a portion that can be completed in situ. According to the invention, the cross section of the prefabricated beam (T), at the joint, widens gradually so that it is then divided into two prismatic elements with narrow rectangular cross section, referred to as shoulders (S), which define a containment compartment, i.e., a formwork, for the subsequent casting.

Description

The present invention essentially relates to the field of prefabricated buildings and, in particular, relates to a new type of connecting element between beam and column elements made of precast reinforced concrete, characterized by ease of installation at the place of work and the presence of formwork into which concrete is poured for completion of the connecting element.

Currently, there is a type of connection element for a beam and a column, which may seem similar to the connection element according to the present invention, since the beam is equipped with lateral end arms for laterally restricting the casting of concrete, which forms the connection element, but the main difference is that in the known In this case, the cross section of the beam is determined by the outer surface of the shoulders without any narrowing of the section of the beam outside the connecting element.

Another type of connecting element for a beam and a column is also known, having the main difference from the connecting element that is the subject of the present invention, namely that it does not provide for the presence of shoulders, and the casting is completely carried out by means of formwork specially provided at the place of work. In this case, there is an obvious practical difficulty in maintaining the beam element before casting, so that the only known application is to conduct experiments aimed at establishing the efficiency of the transfer of stress between the reinforcing bars by means of an I-shaped configuration.

These various structural characteristics, in addition to geometric differences, cause, especially in the first prior art solution, significant waste of concrete. In addition, in the cases mentioned above, difficulties arise in the location and convenient holding of the beam during installation, and the connecting elements thus obtained do not allow cost-effective reconstruction of the integrity of the frame.

From the document No. 1P 2012 144936, a connecting element for a beam and a column made of precast reinforced concrete is also known, in which, unlike the present invention, reinforcing bars are formed of simple straight sections of iron with mounting heads for insertion into the connecting element through through holes, made after installing the beam on the column. In addition, unlike the present invention, in the connecting element described in document No. 1P 2012 144936, the assembly beam is closed at the location of the connecting element on three sides, and therefore there can be no rods protruding from the column, but only straight pieces of iron for subsequent insertion into the connecting element.

For a more complete understanding of the invention, a detailed description is given with reference to the accompanying drawings, in which, by way of non-limiting example, a preferred embodiment of the invention is shown.

In the drawings:

in FIG. 1A shows a three-dimensional view of the ends of a prefabricated beam and a prefabricated column according to the present invention at the stage of forming the connection, with reinforcing means shown in a through view;

in FIG. 1B shows a through view corresponding to the previous view;

in FIG. 2A shows a through top view of the gaps of the beam and column of FIG. one;

in FIG. 2B shows a through view corresponding to the previous view;

in FIG. 3A and 4A, coinciding with FIG. 1 and 2, respectively, a through view of a beam and a column is shown when the assembly of the connecting elements is completed at the place of work; and in FIG. SV and 4B show non-through species corresponding to the previous species.

By structural conditions, the limiting characteristics provided by the connecting element are characteristics of an ideal fixed connecting element.

In the preferred embodiment described herein, the connecting element is essentially formed from:

1) parts connected to the beam T;

2) a part connected to column C; and

3) parts made with the possibility of its completion at the place of work.

1. The part connected to the beam.

The beam under consideration, as a rule, has a rectangular section.

The cross section of the beam T outside the connecting element will hereinafter be referred to as the calculated cross section.

According to particular features of the invention, the cross section of the precast beam T at the connecting element is gradually expanded and then divided into two prismatic elements with a narrow rectangular cross section, hereinafter referred to as shoulders 8, which form an edge for limiting (formwork) of the subsequent casting. In the gap thus formed, which, according to the invention, has the same cross section as the calculated cross section, only one reinforcing means is provided, consisting of longitudinal horizontal rods, the ends of which are in the shape of an “I”, and of brackets 2 located opposite a friend in the inside of the beam

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T and made to be arranged around the longitudinal horizontal rods 1 of the beam T and 3 of the column C, after placing the beam on the column C at the place of work, in the position determined at the construction stage of the reinforced concrete.

The size along the length of section E depends on the diameter of the selected reinforcing means (Ф), as shown in the table below.

2. The part connected to the column.

On the column C, in the place on which the beam T rests, an integral reinforcing means formed of I-shaped bent rods 3, which have the same diameter and are placed in the same place as the rods 1 protruding from the beam T, but made passing horizontally laterally relative to them to ensure the interpenetration of the specified reinforcing means 3 of the column C and the reinforcing means of the beam T, according to the structural tolerances, as shown in FIG. 1. The I-shaped bent rods protrude along the length from the outer surface of the column C to the gap s, as shown in the table ._____________________________________

f S B = s + 250 mm W = S + 125 mm mm mm mm mm 20 540 790 665 22 590 840 715 25 670 920 795 28 830 1080 955 thirty 890 1140 1015 32 950 1200 1075

The dimensions shown are valid for concrete for connecting elements with a compressive strength = 49 MPa.

In the table:

LI is the length of the protrusion of the rods (or bars) 1 or 3 outside the column C or beam T;

E1 - the length of the interpenetration of the rods (or bars) 1 and 3;

E is the length of the section containing the reinforced means of the connecting element to be cast at the place of work.

To obtain dimensions with different strength values, it is necessary to multiply E1 by the ratio 7 / square root of the compressive strength and accordingly update E and LI.

Column C also contains means for temporarily supporting the precast beam T during installation.

In the preferred embodiment described herein, said support means are formed, by way of example only, by a short arm M, which is molded together with column C, and on which the arms 8 of beam T are supported.

3. Part made with the possibility of assembly at the place of work.

After the beam T has been installed in its final position, on the temporary support means formed by the aforementioned console M, the brackets 2 of the reinforcing means are transferred to the position provided by the structure.

According to another particular feature of the invention, the length of said cantilever M is such that it allows workers access to the area between shoulders 8 also from below so as to facilitate the operation of placing brackets 2 along said reinforcing bars 1 and 3.

As soon as the lower part of the area in which the reinforcing means 1 and 3 and the corresponding brackets 2 of the connecting element are closed, the temporary formwork is fixed on the shoulders 8.

Thus, the casting is completed by self-leveling concrete with shrinkage compensation mixed with a mixture with a maximum grain size of 10 mm, preferably reinforced with fiber with a fiber content of 0.5 vol.%, The characteristic strength of which is equal to the characteristic strength of the concrete used to assemble the beam, or more than 1.65 times its size.

Finally, it should be noted that the rods of the reinforced means 1 and 3 of the beams T and columns C may also not be curved I-shaped, but may be rectilinear and connected by connecting means of a known type.

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Claims (9)

CLAIM 1. The connecting element between the beam elements (T) and column elements (C) made of precast reinforced concrete, characterized in that it essentially contains: A) the part connected to the beam (T), equipped with protruding C-shaped reinforcing bars (1); B) the part connected to the column (C), equipped with protruding C-shaped reinforcing rods (3), made with the possibility of installation together with the indicated reinforcing rods (1) of the beam (T); and C) the part made with the possibility of its completion at the place of work; moreover, the cross section of the precast beam (T) at the connecting element is gradually expanded so that it is divided into two prismatic elements with a narrow rectangular cross section, called shoulders (8), which form a bounding section, i.e. formwork, for subsequent casting; moreover, the specified limiting section is accessible and open from the upper, lower and front sides facing the column (C), and these C-shaped reinforcing bars (1, 3) are located in mutually parallel vertical planes, and the column (C) contains a means for temporary supporting the precast beam (T) during installation, the length of which is such that workers can access the area between the shoulders (8) also from below so as to facilitate the operation of placing the brackets (2) along the indicated reinforcing bars (1, 3) when b LCA (T) is located on the column (C). 2. The connecting element according to claim 1, characterized in that in the interval between the shoulders (8) having the same cross section as the beam (T) outside the connecting element, only one reinforcing means is provided in the beam (T), said the reinforcing means consists of longitudinal horizontal rods (1), the ends of which are of a C-shape, and of brackets (2). 3. The connecting element according to claim 2, characterized in that on the column (C), in the place on which the beam (T) rests, an integral reinforcing means formed of C-shaped bent rods (3) that have the same diameter and placed in the same place as the rods (1) of the beam (T), but made horizontally extending laterally relative to them to ensure the penetration of the specified reinforcing means (3) of the column (C) and the reinforcing means of the beam (T). 4. The connecting element according to claim 3, characterized in that the C-shaped bent rods (3) of the column (C) protrude along the length from the outer surface of the column (C) to the gap (W), which depends on the length (B1) of the overlap of the rods (13). 5. The connecting element according to claim 4, characterized in that the part of the connecting element connected to the column (C) also contains means for temporarily supporting the precast beam (T) during installation, such as a short console (M) cast together with column (C), and the specified console serves as a supporting surface for the shoulders (8) of the beam (T). 6. The connecting element according to claim 5, characterized in that the part made with the possibility of its completion at the place of work provides the possibility that, to close the lower part of the section, which is formed by these shoulders (8) and a short console (M) and in which the reinforcing means (1, 3) of the beam (T) and columns (C) are located, as well as the corresponding brackets (2) of the reinforcing means of the connecting element located in the position provided by the structure, a temporary formwork is mounted on the shoulders (8). 7. The connecting element according to claim 6, characterized in that it provides for the possibility of the final casting of self-leveling concrete with compensation for shrinkage. 8. The connecting element according to claim 7, characterized in that said concrete is mixed with a mixture with a maximum grain size of 10 mm, preferably reinforced with fiber with a fiber content of 0.5 vol.%, The characteristic strength of which is equal to the characteristic strength of the concrete used to assemble the beam (T), or exceeds it by more than 1.65 times. 9. The connecting element according to claim 8, characterized in that the size along the length (B) of the section depends on the diameter of the selected reinforcing means (F), as shown in the table f S B = s + 250 mm L = L + 125 mm mm mm mm mm 20 540 790 665 22 590 840 715 25 670 920 795 28 830 1080 955 thirty 890 1140 1015 32 950 1200 1075 - 3 032453