JPH0334963Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial field of application This invention relates to prefabricated prestressed concrete rigid frame structures used in the construction of buildings, etc.

BACKGROUND ART Conventionally, this type of rigid frame structure (hereinafter referred to as PC structure) is generally formed as shown in FIGS. 16 to 18. In the same figure, a is a column, b is a beam, and c
is a tension material c, and as shown in Fig. 16, this tension material c may consist of three types: an upper edge material c ₁ , a hanging material c ₂ , and a lower edge material c ₃ . As shown in Fig. 17, some are made up of a hanging material c ₂ and a lower edge material c ₃ , while others are made of an upper edge material c ₁ and a lower edge material c ₃ as shown in Fig. 18. be.

The problem that the invention attempts to solve However, here is the problem. This is because the conventional structure described above is not economically viable in the following cases.

In other words, it has a relatively small to medium span of about 7m to 14m, and the floor area of the unit divided by girders and girders is 40m ²
~80m This is a structure with a range of ^2nd place. To explain this in terms of diagrams, Figure 15 shows a rigid frame structure such as a building made of a prefabricated PC structure and a reinforced concrete (hereinafter referred to as RC structure) structure, assuming that the load that can be carried is constant, and the span in the girder direction. Span length in the girder direction and construction cost rate when the length is fixed,
It is also a conceptual diagram showing the relationship between the unit floor area divided by girders and girders and the construction cost rate.

Line L ₁ is for the prefabricated PC structure that has been implemented in the past, and line L ₂ is for the RC structure constructed on site. The economically viable range of line L ₁ according to the conventional method is roughly the span.
It is longer than 14m and has a structural scale of 80m2 ^or more in terms of unit floor area. If you attempt something less than that, it will be an extension line shown as a dashed line, and the line L ₂
The difference in construction costs would be so large that it would no longer be viable.

This idea was made to solve this problem, and in a relatively small span area,
The aim is to obtain a PC rigid frame structure that is economically competitive with conventional RC structures constructed on-site.

This invention will be described with reference to FIGS. 1 to 3 showing one embodiment.
The beam 1 has an upper bracket 9 at the end in the length direction; the column 3 made of reinforced concrete has a lower bracket 8 halfway in the height direction; The pillar 3 supports the beam 1 by placing the upper bracket 9 on the lower bracket 8 of the pillar 3; the beam 1
in the longitudinal direction and the lower part in the vertical direction, and the pillar 3
a second tension member 4 provided through each; connecting bars 5, 5 connecting the upper part of the pillar 3 and the beam 1;
a; burying a portion of the lower bracket 8, the upper bracket 9, and the second tendon 4, respectively;
Concrete joint filler 10 placed between the beam 1 and column 3; concrete 7 placed between the beam 1 and column 3 by burying the connecting bars 5, 5a;
It is a prefabricated prestressed concrete rigid frame structure characterized by consisting of. Note that 11 is a wire hole, 12 is a cavity, and 13 is a floor plate. The brackets 8 and 9 are, for example, formed to have a T-shaped cross section, and are overlapped at the plane portion.

4 to 6 show a second embodiment of this invention, in which the beam 1 is formed to have a trapezoidal cross section. 14 and 15 indicate connecting portions. Note that the pillar 3 has a steel structure.

9 and 10 show different types of connecting bars 5a. These show methods for handling when the load acting on the floor assembly is small and when it is large.

Function: The upper edge of the beam 1 is formed so that the bending stress does not depend on the tension material, which simplifies the arrangement of the tension material and facilitates the joining of the column 3 and the beam 1. As shown in FIGS. 11 to 14, tension is exerted only on the lower edge material. Instead of the upper edge material, it is integrally constructed with connecting bars 5, 5a (steel material as an example), and is thickened with concrete 7 poured afterwards, which allows for bending when the upper edge of the beam 1 is in tension. It withstands the moment.

EXAMPLE The construction method of the rigid frame structure of this invention will be described as follows.

A: Installing pillars...The pillars can be built into three layers, or they can be added to each layer.

B: Erection of the beam...The beam has been subjected to primary prestress using a pretension method at the factory, and is warped at the center. It is installed in a fixed position via a bracket or the like embedded in the pillar 3 in advance.

C: Installation of floorboards: By installing the precast floorboards 13, the warpage at the center of the beam 1 is reduced.

D; Arrangement of tendons... for single span or multiple spans, depending on the generally straight wire passage hole 11 prepared along the underlined part of the beam 1 and the wire passage hole provided on the column 3. , the tension members 4 are placed through the columns 3 and the beams 1. Compared to the conventional wiring work, this is a much less labor-intensive work.

E; Construction and tensioning of joint joints...Fill the joints 10 with concrete, etc., wait for it to harden, and tension the outer columns of a single span or multiple spans at once to tighten the column 3.
The entire crimp bonding between the side surface and the end of the beam 1 is completed at the same time, and at the same time, a secondary prestress is introduced into the beam 1 to add the necessary bending resistance force. In this case, since the tendon material 4 can generally be formed into a straight line, it can be used effectively with less loss of tension force due to friction.

F; Column 3 with connecting members 5, 5a at the upper edge of beam 1 end
Connection to... By applying connecting members 5, 5a and post-cast concrete 7 on the side of the column 3 and the end of the beam 1, the connection between the column 3 and the beam 1 is completed, and at the same time at the center of the beam 1. Also, if the space between the floor plates 13 built from both sides of the beam 1 is also poured with concrete, it will be combined with the beam 1,
It would also be easy to raise the beam length.

FIG. 4 shows a case in which a steel column 3 is first erected, a beam 1 and a floor plate 13 are erected thereon, and then concrete is poured around the steel column. In this case, there is no division of the joint that existed between the end of beam 1 and the side of column 3 as shown in Figure 1.
This will be included in column 3 concrete pouring.

This invention is constructed as described above, and the tensioning of the beam 1 by the first tensioning material can be carried out in mass production in advance at a factory. Further, since only the second tension member 4 is required for tensioning work that penetrates the beam 1 and the column 3, the troublesome work of tensioning at the site can be greatly reduced.
Therefore, it is possible to economically create a small-scale assembled prestressed concrete rigid frame structure, which has not been possible in the past.

[Brief explanation of the drawing]

Figures 1 to 3 show examples of this invention, Figure 1 is a diagram showing the outline of a prestressed concrete rigid frame structure, Figure 2 is a sectional view taken along the - line in Figure 1, and Figure 3 is a cross-sectional view taken along the same line. Cross-sectional view, Figure 4 is the same as Figure 2.
FIG. 5 is a sectional view taken along the - line in FIG. 4, FIG. 6 is a sectional view taken along the same line, and FIG. 7 is a perspective view of the beam shown in FIG. 2. FIG. 8 is a perspective view of the beam shown in FIG. 5, FIGS. 9 and 10 show third and fourth embodiments of this invention, respectively, and cross-sectional views of the beam, and FIGS. 11 to 14 are 15 is a schematic diagram of a prestressed concrete rigid frame structure, FIG. 15 is a graph showing the relationship between the span length and construction cost of the conventional same structure, and FIGS. Figure 18 is a diagram showing an outline of a conventional prestressed concrete rigid frame structure. 1... Beam, 2... First tendon, 3... Column, 4...
...Second tension material, 5,5a...Connection bar.

Claims (1)

[Scope of utility model registration request] A first tension member 2 provided in the longitudinal direction below the vertical center of a concrete beam 1 and only on the beam 1; the beam 1 having an upper bracket 9 at the end in the length direction; ; A column 3 made of reinforced concrete having a lower bracket 8 halfway in the height direction; The column 3 supporting the beam 1 by placing the upper bracket 9 on the lower bracket 8 of the column 3; a second tension member 4 provided in the longitudinal direction of the beam 1 and passing through the lower part in the vertical direction and the pillar 3; connecting bars 5, 5a connecting the pillar 3 and the upper part of the beam 1; Concrete joint filler 10 cast between the beam 1 and the column 3 by burying the lower bracket 8, the upper bracket 9, and a part of the second tendon 4; the connecting bars 5, 5;
An assembled prestressed concrete rigid frame structure characterized by comprising concrete 7 buried between the beam 1 and the column 3 by burying the concrete 7.