JPH02292428A - Cast-in-place-concrete-filled type pc girder - Google Patents

Abstract

PURPOSE:To reduce the weight of PC girders by a method wherein a plurality of the PC thin-girders brought to partial width to specified girder width are used, a plurality of the PC thin-girders are arranged in parallel, these PC thin- girders are connected by a connecting means and a cast-in-place concrete filling section is mounted between an opposite-face void. CONSTITUTION:Two PC thin-girders 2, 2 formed in size thinner than specified girder width are opposite-face connected by a separating connecting means 3. The total width of each PC thin-girder 2 is made smaller than the specified girder width W. The two PC thin-girders 2, 2 are installed so that roughened surfaces 8, 8 are mutually faced oppositely to a post previously disposed in upright, and the connection bolts 3 as the separating connecting means are inserted into through-holes 7 and the PC thin-girders are opposite-face connected. A cast-in-place concrete filling section 11 is formed between an opposite-face void. Accordingly, the weight of the PC girders is reduced, and field-work can be conducted safely.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a PC (precast concrete) beam that can be used in various buildings including high-rise buildings and medium- to low-rise buildings.
Especially regarding PC beams used in combination with on-site construction. [Prior Art] Regarding the PC beam of this type of building, the present inventors placed the end of the PC beam on the upper edge of the PC column, and
A frame device including a structure in which the above-mentioned PC columns and PC beams are continuously integrated by forming a concrete casting part in the panel zone between the C beams has been proposed in Japanese Patent Application No. 1983-276420. [Problems to be Solved by the Invention] However, when specifically designing such a PC beam, if the cross-sectional shape is formed to have a predetermined beam width and a predetermined beam height over the entire span, the weight will be large, and of course the length of the span will increase. As the length increases, this weight increases further, and a large moment situation may occur, for example, when a heavy finished PC beam is hoisted to an upper floor by a crane with a long arm span at a construction site.Therefore, improvements must be made to ensure safety. There was room. The present invention was made in view of these problems of PC beams, and aims to further improve the safety of on-site work by reducing the weight of PC beams, and also takes advantage of the advantages of PC beams, which reduce the need for skilled work such as formwork. The purpose is to provide PC beams that can be used for on-site construction with as much retention as possible. [Means for Solving the Problems] The present invention has been completed in accordance with the above object, and uses a plurality of thin PC beams having a partial width with respect to a predetermined beam width, and
A field-cast concrete filling part is formed in the gap facing the C thin beams, and in other words, the present invention is a system in which a plurality of PC thin beams are erected in parallel between columns, with a total beam width of less than a predetermined beam width. A site characterized in that each of the thin PC beams is connected facing each other by spaced connecting means in the beam width direction provided between the thin PC beams, and a concrete filling portion cast on site is formed in the gap between the thin PC beams. Instead of the cast concrete filled type PC beam (Claim 1) and the separated connection means of Claim 1, an integral PC connection bottom plate is formed between each PC thin beam, and the facing gap between each PC thin beam is The present invention relates to a cast-on-site concrete-filled PC beam (Claim 2) characterized in that a cast-on-site concrete filled portion is formed with an opening at the top (Claim 2). [Function] With the above configuration, each PC thin beam of claim 1 is formed to have a partial width obtained by dividing a predetermined beam width, and the PC thin beam of claim 2 is
Although the C-beam is made by connecting PC fig beams with such partial widths by an integrated PC connecting bottom plate, in both cases there is a gap between these thin PC beams, and the gap is filled with concrete poured on site. Concrete is poured on site to form a completed beam of the specified width. [Example] First, the example shown in Figs. 1 to 3 will be explained. In the figure, 1 is a PC beam used for on-site construction according to the present invention, and in this example, the beam is formed relatively thinner than a predetermined beam width. Two PCs!
iIfA2.2 are connected face-to-face by a remote connection means 3. Each of the PC thin beams 2, 2 has a width W in FIG. 1, and the total beam width is less than a predetermined beam width (W in the figure). Then, the lower beam reinforcement 5 is placed in the precast concrete 4.
, 5, and a spiral stirrup 6 formed continuously in a spiral shape with the lower end wrapped around the lower reinforcement 5.5 and the upper end slightly exposed, and a through hole 7 in the beam width direction.
... are provided at predetermined intervals in the beam direction. Moreover, a rough surface 8 of precast concrete is formed on one side thereof. These two PC thin beams 2.2 are connected to the pillar 9.9 that was previously erected.
(PC pillars or cast-in-place pillars, etc.) with the rough surface 8,
8 facing each other and parallel to each other, and as shown in FIG. These are connected facing each other, and an on-site concrete filling part 11 is formed in the gap between the PC thin beams 2.2. In addition to the above connection bolt (and tightening nut paired with it), both P
A separator (or spacer, not shown) may be inserted between the C thin beams 2 and 2. Further, after this connection, the appearance can be simplified by filling the through holes 7 with mortar or the like to hide the bolt heads and tightening nuts. Others, 12, 12 in the figure
14 is the beam reinforcement inserted into the exposed upper end of the spiral stirrup, 13 is the hook hung across the beam reinforcement of both PC thin beams, and 14-... in the figure is the column main reinforcement. Then, on the PC beam l installed in this way,
For example, while installing PC slab plates 15 and 15 (or formwork for slabs assembled on-site) as shown in Fig. 3, a removable bottom plate (not shown) is attached to the bottom surface of the PC beam 1 as necessary. , Fill the gap between the PC thin beams facing each other with on-site concrete 17 (including mortar), for example, together with the concrete pouring of the slab 16 or in a separate operation. In Fig. 3, 18 is a reinforcing bar at the top of the beam in the concrete cast on site, and 19 is a reinforcing bar at the bottom of the beam.

Next, in the embodiment shown in FIG. 4, an integral PC connection bottom plate 20 is formed between each PC thin beam 2, 2 in place of the separated connection means of the previous embodiment, and This is an example in which a field-cast concrete filling part 11 with an upward opening is formed in a facing gap. As a means of forming such a PC beam l, for example, although not shown, a long tin plate or iron plate, etc., which is bent or welded to have a substantially U-shaped cross section, is placed as a core in a formwork, and then concrete is precast. After solidification, it may be removed to form an on-site concrete filling section, or it may be left as is as a part of the PC beam and the inside of the U-shape may be used as an on-site concrete filling section. In each case,
If you attach a sob with the same shape as the rough concrete surface shown in Figure 4 to the above tin plate, etc., the concrete will adhere well. On the other hand, in the embodiment shown in FIG. 5, two PC thin beams 2.2 are connected by a separate connecting means 3, as in the first embodiment, or the lower ends of these PC thin beams 2.2 on the facing gap side are connected. 21, 21 of concrete cast on site are integrally protruded from the respective parts, and hooks 22 and 22 are provided for each round in place of the spiral stirrup continuously formed in the spiral shape of the first embodiment. The difference is that a large number of stirrups 23 are built into the PC thin beam 2.

In the other embodiments shown in FIGS. 4 and 5, other points are the same as in the first embodiment, so the same reference numerals are given in the figures and the explanation thereof will be omitted.

Although not shown in the drawings, the PC thin beams are not limited to the above-mentioned two beams, for example, three or more thin beams formed with a smaller width may be installed between the pillars.

In addition to the above-mentioned connection bolts, the separation connection means for the PC thin beams may include, for example, making the PC thin beams a steel frame structure, exposing a part of the built-in steel frame of each PC thin beam to the facing gap side, and connecting the exposed portions of the steel frames. It is also possible to connect them by bolts, welding, etc.

Although the embodiments have been configured as described above, the present invention does not depart from the scope of the above-mentioned gist. It goes without saying that the structure, material, dimensions, number of members, arrangement, relationships among these, etc. can be changed in various ways and are not limited to the above embodiments. [Effects of the Invention] As a result of the present invention configured as described above, each thin PC beam of claim 1 is formed to have a partial width obtained by dividing a predetermined beam width, and the PC beam of claim 2 is is the partial width P
Although C thin beams are connected by an integrated PC connection bottom plate,
In either case, a facing gap is formed between these thin PC beams, and both have only a partial weight compared to the total weight of the completed beam, so for example, when unloading onto a transport vehicle, lifting by a crane at the site is difficult. It is only necessary to handle a portion of the weight, which makes the work easier even for those who are not highly skilled, and the load on the crane etc. is reduced, improving the safety of the crane work etc.

The on-site concrete-filled PC beam of the present invention is
Since a field-cast concrete filling part was formed in the gap facing the PC thin beam, the PC
Since it has the function of thin flexible formwork or concrete formwork cast on site, formwork work is unnecessary or can be reduced as much as possible, and construction can be completed even with a small number of skilled workers. This makes it easier to secure the necessary personnel. Furthermore, adjust the distance between the separation connecting means provided between each PC thin beam and fill the facing gap with on-site concrete.
f. It is also possible to form finished beams that are suitable for various beam widths.

[Brief explanation of the drawing]

Figures 1 to 3, 4, and 5 show different embodiments, and Figure 1 is a side view of the concrete-filled PC beam poured on site according to the present invention, and Figure 2 is a front view of the same. Figure 3 is a vertical cross-sectional view of the same PC beam after being filled with concrete cast on site.
FIGS. 4 and 5 are longitudinal sectional views of PC beams of the present invention according to other embodiments, respectively, after being filled with concrete cast on site. 1... On-site concrete filling type PC beam 2... PC thin beam 3... Separation connection means l1... On-site concrete filling part 18...-PC connection bottom plate

Claims (2)

[Claims] (1) A plurality of thin PC beams with a total beam width less than a predetermined beam width are installed parallel to each other between the columns, and are connected face-to-face by spaced connecting means in the beam width direction provided between each thin PC beam. A cast-on-site concrete-filled PC beam characterized by forming an on-site concrete filling part in the facing gap of a thin PC beam. (2) Instead of the separated connection means of Claim 1, an integral PC connection bottom plate is formed between each PC thin beam, and an on-site cast concrete filling part with an upward opening is formed in the facing gap of each PC thin beam. A cast-on-site concrete-filled PC beam that is characterized by its unique features.