JPS5949172B2 - Hollow prestressed concrete panel and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves forming a plurality of cavities parallel to the longitudinal direction of the rectangular concrete panel at appropriate intervals in the width direction of the panel, and a plurality of cavities buried along these cavities. This article relates to a hollow prestressed concrete panel (so-called spancrete) made by introducing prestressing using the cibretinsion method into prestressed prestressed steel materials, and its manufacturing method.

The above-mentioned hollow prestressed concrete panel is formed without using a fixed formwork as in the case of producing a general precast concrete panel.

In other words, the required number of PC steel members (PC
An automatic extrusion molding machine equipped with left and right side forms and a rod-shaped core for hollow molding located between these side forms is placed on the bed. While moving from one end to the other,
Hard-mixed concrete is cast to form a long concrete panel with a cavity and smooth left and right sides, etc. Next, this long concrete panel is used as a bed, and the PC steel material is used as before. A similar long concrete panel is formed on top of the previously formed panel by the movement of an automatic extrusion molding machine, and the same process as in the method is repeated to form a long concrete panel into a multilayered form. After the concrete has developed a predetermined strength, the prestress is introduced by releasing the tension on the prestressed steel material, and the concrete is manufactured by cutting the concrete into pieces of each desired length.

Therefore, in a hollow prestressed concrete panel, it is not possible to embed joining metal fittings as seen in general precast concrete panels.

Therefore, at both ends in the longitudinal direction, joining reinforcing bars, etc. are embedded in the cavities by post-processing, and the columns,
Although it is connected to a steel structure such as a beam.

The joining of both sides of the panel in the width direction is carried out using the following two types of killer joint construction methods.

First, as shown in FIGS. 7 and 8, semicircular notch holes 20 are drilled on both left and right sides of the panel, and a steel pipe with reinforcing bars 22 welded to one end is provided in the steel structure 21. 23 are welded, and the panels are placed side by side with the notch holes 20 and 20 facing each other and fitted with the steel pipe 23.
This is a construction method in which mortar 24 is filled to a depth of 0.20 mm.

The other method, as shown in FIGS. 9 and 10, is to drill recesses 25 and bolt insertion recesses in the left and right sides of the panel, each having an arcuate shape when viewed from the longitudinal direction of the panel. 2
A stud bolt 26 is welded to the stud bolt 26, and after the panels are placed facing each other in a predetermined position, a grooved steel 27 with a size that fits into the arcuate recess 25.25 is attached to the stud bolt 26 with a nut 2.
In this construction method, it is installed in step 8 and filled with mortar 24.

However, in these construction methods, the joining structure is such that force is transmitted through the mortar 24, so the joining strength of the panels depends only on the mortar 24, and depending on the degree of filling of the mortar 24, the joining strength becomes extremely low. etc,
The lack of reliability in terms of joint strength was considered to be a drawback of hollow prestressed concrete panels.

In view of the above-mentioned circumstances, the present invention provides a hollow prestressed concrete panel and a manufacturing method thereof that enable a highly reliable joining method.

Embodiments of the present invention will be described below based on the drawings.

Figures 1 and 2 show a hollow prestressed concrete panel (so-called spancrete) A according to the present invention, in which 1 is a rectangular concrete panel having a plurality of cavities 2 parallel to its longitudinal direction. Then, a plurality of PC steel materials (PC steel stranded wires are used, but PC steel rods or PC steel wires may also be used) are buried along these cavities 2. This is the introduction of prestress.

On both left and right sides at a predetermined position in the longitudinal direction of the concrete panel 1, there is a flat plate part 4, a pair of anchor parts 5 made of reinforcing bars bent in an inverted shape welded to the upper surface of the flat plate part 4, and a pair of anchor parts 5, which also stand up. A joining hardware 7 constituted by a pair of rising portions 6 made of small-sized reinforcing bars,
The flat plate part 4 is buried so that its outer edge is located inside the left and right side surfaces Sl of the concrete panel 1, and its lower surface is flush with the lower surface S2 of the concrete panel 1.

Note that each anchor part 5 is connected to the PC steel material 3 by means such as wire binding.

Further, the amount of rise of the rising portion 6 from the lower surface of the flat plate portion 4 is set equal to the required concrete covering thickness of the PC steel material 3, and the PC steel material 3 is in contact with the upper surface of the rising portion 6... .

Next, a method of joining the panel A and the steel structure 8 such as columns and beams will be explained.

As shown in FIGS. 3 and 4, using a drilling machine (not shown), drill holes in the left and right sides of the concrete panel 1, and in the corresponding positions of the joining hardware 7 in the panel thickness direction. After drilling a semicircular notch 9 in the hole and sticking out a part of the outer edge of the flat plate part 4, the panel A is placed on the steel structure 8 and soil 7, and a welding rod is inserted through the notch 9. By inserting the panel A and welding the exposed outer edge of the flat plate portion 4 and the steel structure 8, the panel A and the steel structure 8 are joined.

Even when a plurality of panels A are juxtaposed with their left and right side surfaces in close contact with each other, they can be joined in the same manner as described above.

Next, a method for manufacturing the hollow prestressed concrete panel A will be described.

A plurality of PC steel members 3 are arranged above the bed 11 over a length of 100m to 150m with one end held by the fixing part 10 and separated at a predetermined interval in the panel width direction. Then, the other end side of the PC steel material 3... is fixed to the fixing part 10
It is held by a holding device 12 which is displaceable in the far and near direction with respect to the object.

(See A in Fig. 5) Next, the holding device 12 is moved away from the fixing part 10 to apply tension to the prestressing steel materials 3... , the joining metal fittings 7 are fixedly connected to each end of the panel at a predetermined interval in the longitudinal direction, so that the outer edge of the flat plate part 4 is connected in the width direction of the panel. It is placed on the bed 11 with its lower surface in surface contact with the bed 11, located inside the positions corresponding to both side surfaces (the movement paths of the side forms to be described later).

(See the opening in Fig. 5) In addition, applying tension to the PC steel material 3 and connecting the joining hardware 7 to the PC steel material 3 are as follows:
You can do either one first.

Further, the PC steel materials 3 are prevented from hanging down at the rising portions 6 of the joining hardware 7.

Next, the known structure includes a concrete charging hopper 13, left and right side forms 14..., a rod-shaped core 15 for hollow forming located between the side forms 14..., a compaction vibrator 16, etc. automatic extrusion molding machine 1
7 from one end of the bed 11 to the other end, hard mixed concrete is poured so that the cavities 2... are formed and the left and right sides or side forms 14... are smooth in the longitudinal direction. The finished long concrete panel A1 is shaped.

(See C in Figure 5.) Next, the long concrete panel A1 is used as a bed 11, and the PC steel material 3... is stretched under tension on top of it, and the joining hardware 7... is set. , the automatic extrusion molding machine 17 is moved to form a similar long concrete panel A2 on top of the panel Al, and the same process is repeated one after another to form a multilayered long concrete panel as shown in FIG. Shaku concrete panel A1. A2. A3, A4...
・Mold.

After confirming that the concrete has developed a predetermined strength, the tension on the prestressing steel material 3 is released, prestress is introduced into the concrete part due to its elastic contraction, and after that, the long concrete panel Al, A2, A
8. Using a cutting machine not shown in the drawings, cut the A4 pieces in layers to the desired length (see Figure 5-2) to obtain the hollow prestressed concrete panels A shown in Figures 1 and 2. It is.

As described above, the hollow prestressed concrete panel according to the first invention has the outer edge of the joining hardware located inside the left and right side surfaces of the concrete panel, and
Since it is buried so that the bottom surface is flush with the bottom surface of the concrete panel, when joining it to the steel structure, a part of the outer edge of the joining hardware must be punched out using an automatic drilling machine, etc. , it is now possible to weld with steel structures, and the joint strength can be constantly improved in a stable state.

In addition, since the joining hardware is inserted into the center of both sides of the panel in the width direction, even when the panels are joined with their sides closely aligned, the edge of the hardware and the adjacent A gap is formed between the panel and the side surface, and the above-mentioned welding can be performed.

In the method for manufacturing a hollow prestressed concrete panel according to the second invention, since the joining metal fittings are arranged inside the movement path of the side form, there is no problem in forming due to the movement of the automatic extrusion molding machine, and, Since the prestressing prestressing prestressing steel material is effectively used and the joining hardware is connected to it, the joining hardware can be easily positioned and fixed, and as mentioned above, a highly reliable joining method is possible. It is now possible to easily manufacture hollow prestressed concrete panels.

[Brief explanation of the drawing]

The drawings show an embodiment of the hollow prestressed concrete panel and its manufacturing method according to the present invention, in which Fig. 1 is a partially cutaway perspective view of the panel, Fig. 2 is a longitudinal sectional view of the main part, and Fig. 3 is a joined state. FIG. Figure 4 is a sectional view taken along the line a-a' in Figure 3, and Figure 5 is a plan view showing the manufacturing process. 1 shows the concrete placing process, and 2 shows the cutting process. Fig. 6 is a side view showing the manufacturing state, Fig. 7 is a plan view of the main parts showing the joining state of the conventional panel, and Fig. 8 is b-b of Fig. 7.
9 and 10 show another conventional example, FIG. 9 is a vertical sectional view of the main part, and FIG. 10 is c-c' of FIG. 9.
FIG. A...Cavity prestressed concrete panel,
SL...Left and right sides, S2...Bottom surface, 1
... Concrete panel, 2 ... Cavity, 3 ... PC steel material, 4 ... Flat plate part, 5
... Part of the anchor, 7... Joining hardware,
11... Bed, 17. Flexible extrusion molding machine.

Claims (1)

[Claims] 1. A plurality of cavities parallel to the longitudinal direction of the rectangular concrete panel are formed at appropriate intervals in the width direction of the panel, and a plurality of PCs are buried along these cavities.
A hollow prestressed concrete panel in which prestressing is applied to the steel material using the cibrenchion method,
Bonding hardware is buried in the left and right sides of the concrete panel so that its outer edge is located inside the left and right side surfaces of the concrete panel, and its lower surface is flush with the lower surface of the concrete panel. A hollow prestressed concrete panel characterized by: 2 A plurality of PC steel members are stretched under tension above the bed, and the upper part is covered with an automatic machine equipped with left and right side forms and a plurality of hollow molding rod-shaped cores located between these side forms. Moving the extrusion molding machine along the prestressing steel material, forming a plurality of cavities parallel to the longitudinal direction of the rectangular concrete panel at appropriate intervals in the width direction of the panel, and burying the cavities along these cavities. In order to manufacture a hollow prestressed concrete panel in which prestressing is introduced into the prestressed prestressed steel material by the sive retinsion method, a flat plate is placed on the upper surface of the bed and at a position inside the movement path of the side form. and a part of the anchor, the part of the anchor is connected to the part of the P.
A hollow prestressed concrete panel connected to C steel material, placed in a state where the flat plate part is in surface contact with the upper surface of the bed, and then concrete is placed by moving the extrusion molding machine. manufacturing method.