JPS621972A - Inner mold frame for producing u-shaped semi-fabricated concrete beam - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an inner formwork for manufacturing semi-prefabricated concrete 1,11, which has a U-shaped cross-sectional shape and has a cotter formed on its inner surface. Regarding.

[Conventional technology]

Semi-prefabricated concrete beams are attracting attention as a method that can reduce costs and shorten the construction period, since the amount of formwork work can be reduced and most of the shoring can be omitted.

In particular, a device having a U-shaped cross-section has been proposed as a device that reduces the weight of the unit and allows for efficient work such as lifting and installation on site. By making U-shaped semi-prefabricated concrete beams like this one not only function as formwork, but also structurally integrated with concrete cast on site, it is possible to make the entire beam more compact and reduce costs. In order to achieve this, the joint between the half-cast concrete part and the cast-in-place concrete part must be able to sufficiently transmit shear force.

On the other hand, so-called shear connectors that transmit shear force include those in which reinforcing bars, bolts, etc. are appropriately protruded, and those in which a wire mesh or the like is interposed. Generally, in half-finished concrete products, a cotter formed in an uneven shape is often used as a shear connector on the joint surface with the concrete to be poured on-site. The formed one is proposed.

[Problems to be Solved by the Invention] However, J-shaped prefabricated concrete beams with dents formed on the inner surface have not yet been manufactured with good workability due to the following problems. In other words, when forming the 1IiTh type of the inner form used to form the kotta on the inner surface, the inner form cannot be pulled upward as it is, as in the case of creating the 13-shaped groove in C1 in general. For example, if you want to create a cotter binding with ζ unevenness arranged in a checkerboard pattern, move the inner formwork in the direction approximately perpendicular to the inner surface to a height higher than the height of the unevenness of the cotter. After that, it is necessary to pull it upward. This is because it is difficult to properly demold the inner mold that forms the kotta.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, it is an object of the present invention to provide an inner formwork with a cotter formed on the inner surface and with which a TJ type ready-made concrete beam can be fabricated with good workability.

[Means for solving problems]

The characteristic configuration of the inner formwork for manufacturing U-shaped semi-prefabricated concrete 1/beams according to the present invention includes a pair of weir plates with convex portions formed on the surface.
The respective protrusions face outward, and the lower ends of the weir plates are fixed in position to form a gap with a width larger than the height of the protrusions. The band-shaped weir plate that closes the gap is connected and fixed to the compatible weir plate.

[For production]

In other words, since the pair of upright weir plates and the band-shaped weir plate for forming the kotsuta on the inner surface of the IJ type prefabricated concrete beam are constructed separately, the inner mold made of each of these weir plates is When demolding the frame, first remove the band-shaped weir plate, then use the gap that the band-shaped weir plate was blocking to move the compatible weir plate in a direction approximately perpendicular to the inner surface of the beam. By positioning the lower edge of the standing weir plate in the gap that is larger than the height of the convex part formed on the standing weir plate, the standing weir plate can be completely removed from the inside surface of the half-made concrete beam. It is possible to remove the mold.

〔Effect of the invention〕

As a result, the inner formwork, which tends to be difficult to demold due to the increased adhesion area with concrete, can now be easily demolded and removed. In addition, even if the cotter has irregularities arranged in a checkered pattern, for example, the convex parts of the standing weir board can be completely extracted from the four parts of the cotter, making it extremely easy to pull out the standing weir board. -L
I am now able to do some things.

Therefore, as a whole, it has become possible to create a U-shaped semi-prefabricated concrete beam with a groove formed on the inner surface with good workability.

〔Example〕

The present invention will be described in detail below based on the drawings.

FIG. 1 shows a cross section of a formwork for manufacturing a U-shaped semi-fabricated concrete beam according to the invention. This formwork is the inner formwork (Sl)
The inner formwork (S+) consists of a pair of standing weir plates (1) made of steel plates and their lower edges (1).
a) It consists of a band-shaped weir plate (2) located between the two.

Compatible weir plate (1) 11. Glue the inner formwork (Sl) (on the side, multiple convex parts to form a kotsuta on the inner side of the IJ type upper semi-prefabricated concrete beam (3) Each convex part (3) is made by cutting and welding a flannel or bar, and as shown in Fig. 4, is arranged in a checkered pattern when viewed from the front. Cast on-site using a checkered kotsuta formed on the inner side of a U-shaped soil + j% concrete beam manufactured using a frame (S+):
At the joint surface with the 7-inch l-, shear force can be effectively transmitted in both the vertical and horizontal directions over a wide area.)
It is set as. On the surface opposite to the surface having the convex portion (3),
Flat bars are welded at appropriate locations in the longitudinal direction to form vertical ribs (4), and flat bars are welded between adjacent vertical ribs (4) to form horizontal ribs (5).
a) and (5h) are formed.

In addition, the lower edges (1a) of the compatible weir plates (1) are bent at approximately right angles to the vertical portions of the weir plates (1), and the lower edge (1a) of the lower edges (1a) A plurality of rib-like protrusions (6) are formed along the longitudinal direction of each of the protrusions. The lower edges (1a) of both weir plates (1) are positioned so as to form a gap with a width (I7) larger than the height (p) of the checkered convex portion (3) mentioned above. The band-shaped weir plate (2) is provided to close this gap.

On the lower surface of the strip weir plate (2) in the longitudinal direction, there is a dual weir plate (1).
A protrusion (7) is formed at a position corresponding to the rib-like protrusion (6) formed on the lower edge (1a) of the protrusion (7).
and the rib-like protrusions (6) form unevenness on the inner bottom surface of the LJ-type countersunk ready-made concrete beam. In the figure (8) is an angle net for reinforcement. Further, (19) and (20) are reinforcing bars buried in the IJ type half-half concrete beam.

As shown in Figures 1 to 3, a plurality of columns (9) are erected at appropriate positions in the longitudinal direction of the band-shaped weir plate (2), and the upper ends of each column (9) are connected. A reinforcing member (lO) made of angle steel is provided.

And C1 This reinforcing member (10) and compatible membrane weir plate (1) -
The horizontal rib (5a) at one end of the weir plate (1) is fixed to the formwork attachment member (11) at multiple locations in the longitudinal direction of the weir plate (1).

Furthermore, members (12) having holes (12a) passing through in the vertical direction are welded and fixed to the lower edge (1a) of the compatible weir plate (1) so as to face each other. On the other hand, a pair of bottle-shaped members (13) that engage with the holes (12a) located at opposite positions are attached to the band-shaped weir plate (2), and the holes (12a) and the pin-shaped members (13) By means of the engaging part (F) consisting of
2) are connected and fixed.

The engaging portions (F) are provided at a plurality of locations along the longitudinal direction of the inner formwork (S,). In addition, a protrusion (14) is further formed at the tip of the protrusion (7) on the lower surface of the band-shaped weir plate (2) where the pin-shaped member (13) is attached, and a U-shaped semi-prefabricated concrete bottom beam ( A hole (11) is formed at the bottom of the four parts (22) on the inner bottom surface of B).

This hole (H) is used when removing the inner formwork (Sl) after manufacturing the U-shaped semi-prefabricated concrete beam (B).

That is, when demolding the inner formwork (Sl), first, the formwork attachment member (11) is removed, and then the band-shaped weir plate (2) is pulled upward together with the supports (9) and the like. After that, see Figure 5 (
As shown in a) and (0), the compatible weir plate (1) is removed from the concrete surface using a demolding tool (15).

MSt type! (15) is a pin (17) that is concentric with this rond (16) and an eccentric pin (
18) are fixed at different heights.

Then, as shown in Figure 5 (a), the rondo (16
) and the concentric tip of the pin (17) into the hole (l()) formed on the concrete bottom inside the ditch, and insert the tip of the rond (16) and the eccentric pin (18) into one vertical It is inserted into the hole (12a) provided in the lower edge (1a) of the weir plate (1).

In this state, as shown in Figure 5(n), the rondo (16
) to the left in the diagram, the vertical weir plate (
1) The lower side can be released from the concrete surface. Next, the upper side of the standing weir plate (1) is released from the concrete surface using a tool such as a crowbar, and the above-mentioned operations are performed sequentially along the longitudinal direction of this inner formwork (Sl). The entire one VF weir plate (1) can be demolded.

At this time, I explained it earlier. L sea urchin, both A and 1 installation I! Handling (
1) The lower edge (1a) has a width (J) that is larger than the height (l) of the convex part (3) formed on the surface of the standing weir plate (1).
[,), and by utilizing this gap that was blocked by the strip weir plate (2), one vertically installed lI + ff1 (1) was moved in a direction approximately perpendicular to it. Move! It is possible to do so.

And, the edge (1a) of this standing weir plate (1) is -1-
With the convex portion (3) formed on the surface of the IJ-type concrete beam (B) positioned in the above-mentioned gap, the convex portion (3) formed on the surface of the IJ-type concrete beam (B) is ) of the fourth part (2
]), and this ear weir plate (
1) can be easily pulled upward.

The other standing weir plate (1) can also be demolded by the same procedure as described above.

Next, the process of manufacturing a semi-prefabricated concrete beam of type ( ) using the inner formwork (Sl) according to the present invention will be explained.

First, the outer formwork (SO) consisting of the 61, 1, and 1 side weir plates shown in Figure 6 (a) was assembled. Next, as shown in Figure 6 (11), inside the outer formwork (SO),
The main reinforcement (19) and stirrup (20) are arranged.

Then, as shown in FIG. 6(C), the outer formwork (Sl) described earlier is attached to the member (11) to which Pol 1 is fixed.
So) is fixed with bolts. Thereafter, as shown in FIG. 6(d), concrete 1) is placed between the inner formwork (S) and the l formwork (SO) and cured.

Thereafter, when removing the inner formwork (Sl) and the outer formwork (SO), for example after four hours have elapsed, first the formwork is removed (
<Part 1J' (II) was removed, and then the inner formwork (Sl
) will be removed. In this state, as shown in Figure 5 (
As shown in a) and (D), the compatible weir plate (1) of the inner formwork (Sl) is demolded and removed using a demolding tool (15). After that, the outer formwork (SO) was also demolded, and the N-type semi-prefabricated concrete beam with an IJ-shaped cross section and a cotter (C) formed on its inner surface, as shown in Figure 6 (f). (B) is obtained.

In carrying out the present invention, the shape of Kotta (C) 11: i!
For example, instead of the checkered pattern described in the previous embodiment, it may be rib-shaped or island-shaped. Weir plate (+
) The shape of the convex portion (3) formed on the surface of the convex portion (3) and its arrangement can be changed as appropriate.

[Brief explanation of drawings]

The drawings show an embodiment of the inner formwork for manufacturing LJ type prefabricated concrete beams according to the present invention, FIG. 1 is a sectional view of the formwork for manufacturing () type semi-prefabricated concrete beams, and FIG. A plan view of the frame, Fig. 3 is a partially cutaway perspective view of the inner form, Fig. 4 is a partially enlarged perspective view of the inner form, and Figs. 5 (a) and ([+) show the removal of the inner form. Cross-sectional view showing the molding process, Figure 6 (a) to next)
1 is a sectional view showing the manufacturing process of a U-shaped semi-prefabricated concrete beam. (1)... Vertical weir plate, (2)... Strip weir plate, (3)... Protrusion, (12a)...
・Hole, (13)...Pin-shaped member, (I4)...
...Protrusion, (B) ...IJ type prefabricated concrete beam (C) .....

Claims (1)

[Claims] [1] Has a U-shaped cross-section, and has a cotter (
An inner formwork for manufacturing a semi-prefabricated concrete beam (B) formed with C), in which a pair of weir plates (1) each having a convex portion (3) formed on its surface is placed on the outside of the semi-prefabricated concrete beam (B). The lower edges (1a) of the standing weir plates (1) are arranged facing each other so as to face each other, and the width (L) is larger than the height (l) of the convex part (3).
An inner formwork for manufacturing a U-shaped semi-prefabricated concrete beam, which is fixed in position to form a gap, and a band-shaped weir plate (2) that closes the gap is connected and fixed to a compatible weir plate (1). [2] The means for connecting and fixing the coexistence weir plate (1) and the band-shaped weir plate (2) are formed at a plurality of locations facing each other on the lower edge (1a) of the coexistence weir plate (1) in the vertical direction. a plurality of pairs of holes (12a) penetrating through the belt-shaped weir plate (2), and a pin-shaped member (
13), and the belt-shaped weir plate (2) has a protrusion (14) on the lower surface of the place where the pin-shaped member (13) is formed.
An inner formwork for manufacturing a U-shaped semi-prefabricated concrete beam according to claim 1, comprising: [3] Claim No. [1], wherein the convex portions (3) are arranged in a checkered pattern with respect to each of the upright weir plates (1).
An inner formwork for manufacturing a U-shaped semi-prefabricated concrete beam according to item 1 or item [2].