JPH10102660A - Precast concrete board and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure that wiring is made reliably at a design position at the time of top concrete placement by leading both ends of a PC steel wire out from a concrete board in a manner of bending downward along the inside of a truss member. SOLUTION: A truss member 3 is formed by joining a single upper-end member 4 and two lower-end members 5, arranged in a triangular state, with a corrugated lattice member 6. The truss members 3 are arranged at an appropriate interval along the longitudinal direction in parallel. Both ends of a PC steel wire 7 which are generally bent downward, are fitted to the inside of the truss member by fixing with hooking hardware hooked to the lattice member 6. By placing concrete so that the center of the PC steel wire 7 and the lower part of the truss member 3, which are tensed with a prescribed tension, may be buried, a concrete plate is formed as a precast concrete board 1. The top concrete is placed astride beams to ensure that the position of burying the PC steel wire 7 will not change.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a precast concrete plate and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, precast concrete members have been widely used for the purpose of resolving extreme labor shortages and consolidating labor. In particular, most precast concrete plates are used to construct floor slabs.When this precast concrete plate is used in buildings with large spans, compressive force is applied to the steel plates to increase bending resistance. Has been granted.

[0003] The floor slab to which the prestress has been applied is, as shown in FIG.
The top concrete 23 is cast by wiring a tensioning material such as this, and after this hardens, the PC steel wire 22 is formed by tensioning.

[0004]

However, in the conventional floor slab to which prestress has been applied, the top concrete is cast by simply placing a PC steel wire on a precast concrete plate. There has been a problem that the PC steel wire sometimes moves and cannot be wired to a predetermined location, that is, a design position.

[0005] The present invention has been made in view of these problems, and an object of the present invention is to provide a precast concrete plate in which a PC steel wire does not move at the time of placing concrete, and which is securely wired at a design position, and a method of manufacturing the same. It is to provide.

[0006]

According to the precast concrete plate of the present invention for solving the above-mentioned problems, one upper and two lower streaks arranged in a triangular shape are corrugated lattice streaks. In a precast concrete plate in which connected truss bars are arranged side by side at appropriate intervals in a state where the upper part thereof protrudes from the concrete plate, a tension member is disposed in the truss bar, and an end of the tension member is provided. The part is derived from a concrete plate. In addition, the method of manufacturing a precast concrete plate is such that one upper and two lower streaks arranged in a triangular shape are lattice-shaped lattice streaks arranged on a grid-like reinforcing bar arranged in a formwork. After arranging the truss bars connected in parallel in parallel at appropriate intervals, wiring the tension members inside the truss bars so that the central portion bends downward, and then casting concrete in the formwork. Features. Thus, even if the precast concrete plate is laid between the beams and the top concrete is laid, the laying position of the tendon does not change and, of course, does not move. In addition, since the tendon is arranged along the truss bar, it can be securely wired at the design position, and the PC steel wire can be easily and reliably wired to a predetermined location.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a precast concrete plate and a method of manufacturing the same according to the present invention will be described below with reference to the drawings. 1 is a cross-sectional view of a precast concrete plate, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is BB of FIG.
FIG. 4 is a cross-sectional view taken along line CC of FIG. 1, and FIG. 5 is a perspective view of the truss bar with a tendon member hooked.

As shown in FIGS. 1 and 2, the precast concrete plate 1 has truss bars 3 arranged in parallel along the length direction of the concrete plate 2 at appropriate intervals.
The lower part is buried in the concrete plate 2 and formed.

The truss bar 3 is composed of a lattice bar 6 whose one upper bar 4 and two lower bars 5 are arranged in a triangular shape.
PC steel wire 7 which is formed by joining
Are wired.

Only the central portion of the PC steel wire 7 bent downward is buried in the concrete plate 2, and both ends thereof are led out of the concrete plate 2 and attached to the truss bars 3 by holding metal fittings.

As this holding metal, a locking metal 9 is used, and the locking bay portion 9a is hooked on the lattice streak 6, and is vertically moved by using this as a guide.

Since the latch 9 is always urged inward, it can be fixed at any position even if the lattice 6 is moved up and down. Therefore, the PC steel wire 7 is wired as a whole by fixing both ends to the locations shown in FIGS. 3 and 4.

Although the latch 9 is set before the PC steel wire 7 is wired, it can be welded to the lattice 6 after the setting or after the PC steel wire 7 is wired.

FIG. 8 shows a case in which the holding fitting is a hanging fitting 11. The PC steel wire 7 is hung on the upper streak 4 and suspended, and the PC fitting is changed by changing the length of the hanging fitting 11. The steel wire 7 is wired in an arbitrary shape as a whole.

Next, a method for manufacturing the precast concrete plate will be described with reference to FIG. First, reinforcing bars 13 are arranged in a grid on the formwork 12, and truss bars 3 are arranged on the forming frames 12 in parallel at appropriate intervals and fixed.

Next, the latch 9 is set on the truss bar 3 and the height thereof is adjusted and then fixed, but this can be fixed to a predetermined height in advance. The latch 9 is set only at both ends of the truss bar 3, but not at the center.

After the hook metal 9 is set, the PC steel wire 7 is inserted into the truss bar 3 from the end and is hooked by the hook metal 9 so that the PC steel wire 7 is inserted into the truss bar 3. Wired in a state fixed to

Next, the PC steel wire 7 is tensioned with a predetermined muscle tension, and concrete is poured into the formwork 12. After the concrete is hardened, the concrete is released from the mold to complete the prestressed precast concrete plate 1. I do.

The PC steel wire 7 may be tensioned after the concrete is hardened to apply a prestress.

[0020]

According to the present invention, the tension members are provided in the truss bars arranged in parallel with the concrete plate at appropriate intervals, and the ends of the tension members are led out of the concrete plate.
Even if the precast concrete plate is laid between the beams and the top concrete is laid, the laying position of the tendon does not change and does not move even when the top concrete is laid.

Since the tension members are provided along the truss bars, they can be securely wired to the design position.

When the holding metal is a hanging metal or a hanging metal, the tension member is moved downward by moving the hanging metal up or down or by changing the length of the hanging metal depending on the location. Wiring can be made into a curved shape or any other shape.

One upper muscle and two lower muscles, which are arranged in a triangular shape, are arranged in parallel at appropriate intervals with truss bars connected by corrugated lattice bars, and inserted into the truss bars. When the concrete is cast after adjusting the height of the passing tension material with the holding bracket to make the center part bend downward,
The PC steel wire can be easily and reliably wired to a predetermined location.

[0024] A precast concrete plate in which PC steel wires are wired at predetermined positions can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a precast concrete plate.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view taken along line CC of FIG. 1;

FIG. 5 is a perspective view of a truss bar.

FIG. 6 is a sectional view of a main part of a precast concrete plate.

FIG. 7 is a perspective view of a latch.

FIG. 8 is a cross-sectional view of a main part of a precast concrete plate using hanging metal fittings.

FIG. 9 is a cross-sectional view illustrating a method for manufacturing a precast concrete plate.

FIG. 10 is a sectional view of a conventional precast concrete plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Precast concrete board 2 Concrete board 3 Truss bar 4 Upper bar 5 Lower bar 6 Lattice bar 7 PC steel wire 9 Hanging bracket 11 Hanging bracket 12 Formwork 13 Reinforcing bar

Claims (7)

[Claims] 1. A truss bar in which one upper bar and two lower bars arranged in a triangular shape are connected by a corrugated lattice bar, and a truss bar is appropriately spaced with its upper part protruding from a concrete plate. A precast concrete plate, wherein a tension member is provided in the truss bar, and an end of the tension member is led out of the concrete plate. 2. The precast concrete plate according to claim 1, wherein the tension member is tensioned by pretension or post tension. 3. The precast concrete plate according to claim 1, wherein the tension member is fixed by a holding bracket attached to a truss bar, and the height of the holding bracket is variable. 4. The concrete plate according to claim 3, wherein the holding fitting is a hanging fitting attached to an upper end streak or a hanging fitting hung between lattice streaks. 5. An upper end muscle and two lower end muscles arranged in a triangular shape are connected to a lattice-shaped reinforcing bar arranged in a formwork by a wavy lattice bar. Precast wherein truss bars are arranged in parallel at appropriate intervals, and a tension member is wired inside the truss bars so that the central portion bends downward, and then concrete is poured into the formwork. Manufacturing method of concrete board. 6. The precast concrete plate according to claim 5, wherein the tension member is tensioned by pretension or post tension. 7. The precast concrete plate according to claim 5, wherein the tension member is fixed by a holding bracket attached to a truss bar, and the height of the holding bracket is variable.