JPH0366857A - Consolidating method for beam of wide u-shaped pc plate - Google Patents

Abstract

PURPOSE:To shorten the construction period by previously implanting projecting objects such as mild steel bar in the bottom of a U-form PC plate beam formed in a large width, applying post-placing concrete to this beam bottom, and thereby accomplishing a consolidated structure. CONSTITUTION:The bottom of a U-shaped PC plate beam 1 formed in a large width is put in contact with a stirrup 4 wound on a main rod 3. A plurality of projecting objects 2 such as truss bar, bent piece of mild steel bar, and inserts are previously implanted in the bottom of this PC plate beam 1. Then post- placing concrete 5 is applied so that the projecting objects 2 are secured in a core, and the PC plate beam 1 and post-placing concrete 5 are consolidated. Thereby the efficiency of assembly work can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for integrating wide U-shaped PC board beams.

[Prior Art] In recent years, in prefabricated buildings, rigid frame construction methods using precast concrete (hereinafter abbreviated as PC) have been increasing in order to streamline and shorten the construction period.

In this case, the weight of the PC used for the beam is important in construction planning, and in this respect, the U-shaped half PC beam is lightweight,
It has many advantages, such as the ability to use lap joints for the main reinforcement joints, and it is also possible to form flat, wide beams by combining it with a flat slab structure using prestressed steel wire to diversify the use of space.

Conventionally, the flat wide U-shaped PC board beam is a stirrup b of a beam a1 as shown in FIG. 6(a).

The PC board CI can be installed on the outside of the PC board c2, or the stirrup b2 can be driven into the PC board c2 as shown in (b), or the stirrup b3 and the main bar d can be installed as shown in (c).
Construction methods are used, such as driving a part of 3 into the PC board c3, or driving the main reinforcement d4 and stirrup b4 into the PC board c4 as shown in Figure (D).

[Problem to be solved by the invention] The conventionally used U-shaped PC plate beam formwork has the same configuration as a normal reinforced concrete (RC) girder, and the ratio of the beam back and beam width is It is about 1.5 to 2.0, and the width is 6
It was about 0 to 70 cm. For this reason, the thin PC at the bottom of the beam
Even if the plate (hereinafter abbreviated as PCF) bears high stress, if there is a mesh or cotter on the joint surface that is conventionally used, the restraint by the PCF on both sides will be large and sufficient strength can be obtained. I know that.

However, when flat beams are used as flat slabs or prestressed beams, the beam width exceeds 1 m, and the ratio of beam back to beam width becomes approximately 0.3 to 0.5.
Some mechanical coupling means will be required for the integration of the plate beams.

The present invention was made in order to solve these conventional problems, and in particular, the technical problem is to provide a simple method of integrating the beam bottom of a wide U-shaped PC board beam with post-cast concrete. It is something.

[Means for Solving the Problems] As a means for solving this technical problem, the present invention provides a method in which protrusions such as reinforcing bars are planted in advance at the bottom of a U-shaped PC board beam formed wide, The gist of this project is to integrate post-cast concrete by pouring it into the bottom of the beam.

[Function] The protrusions planted in advance on the bottom of the U-shaped PC board beam act as a binding material when post-cast concrete is poured, and the protrusions are fixed in the post-cast concrete. By doing so, it is possible to integrate the beam bottom of the U-shaped PC plate beam with the post-cast concrete.

[Example] Hereinafter, the present invention will be explained in more detail with reference to illustrated examples.

In the figure, l is a wide U-shaped PC board beam, and a plurality of protrusions 2 made of reinforcing bars or the like are installed in advance on the bottom side of the beam. For example, as shown in Fig. 2, a truss bar 2a is used, as shown in Fig. 3, a bent reinforcing bar 2b is used, or as shown in Fig. 4, an insert member 2c is applicable. There are some that use a core stirrup 2d, and others that use a core stirrup 2d as shown in FIG.

As shown in FIG. 1, the U-shaped PC plate beam 1 formed in this way is brought into contact with the beam bottom side against the stirrup 4 wrapped around the main reinforcement 3, and post-cast concrete 5 is poured. It is integrated by this.

At this time, the protrusion 2 is fixed in the post-cast concrete 5, that is, within the core, and the U-shaped PC board beam 1 and the post-cast concrete 5 can be strengthened and integrated. Therefore, on-site construction is much easier than in the past, improving work efficiency and shortening the construction period.

Incidentally, in the case of the truss bar shown in FIG. 2, an upper chord member (not shown) may be provided. Furthermore, if the beam width B of the U-shaped PC plate beam is narrow, the number of the protrusions may be reduced or it may be possible to use only one protrusion.

[Effects of the Invention] As explained above, according to the present invention, protrusions such as reinforcing bars are planted in advance at the bottom of the U-shaped PC board beam formed wide,
Since this is a construction method in which post-cast concrete is poured on the bottom side of the beam and integrated, when the post-cast concrete is poured, the protrusions are fixed in the post-cast concrete as a binding material, and the U
Not only can the beam bottom of the type PC board beam be strongly integrated with the post-cast concrete, but also the thin U-shaped PC board beam can be applied to wide beams, providing excellent effects. Furthermore, since it is extremely easy to construct on-site, it has the advantage of improving assembly work efficiency and shortening the construction period.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention, and FIGS. 2 to 5 each show the form of a protrusion in other embodiments of the present invention. Cross section, (
B) is a sectional view seen from the side, and Figures 6(A) to 6
(D) is a sectional view of a main part showing a conventional example. 1...U-shaped PC board beam 2...Protrusion 3...
Main reinforcement 4... Stirrup 5... Patent application for post-cast concrete - Person Shimizu Corporation (711 Kano Q dimensions Figure 5 (A) (B) d Figure 6 (A) (B) (C) (d)

Claims (1)

[Claims] A wide U-shaped PC board characterized by pre-planting protrusions such as reinforcing bars on the bottom of a wide U-shaped PC board beam, and pouring post-cast concrete on the bottom side of the beam to integrate the beam. An integrated construction method for plate beams.