JP2602351B2 - Reinforced concrete structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a reinforced concrete structure.

(Prior Art) Conventionally, when prestress is introduced into a reinforced concrete beam, a sheath is buried inside the beam so as to be positioned at the upper end at the beam end and at the lower end at the center, and a PC is inserted into the sheath. After the steel rod was inserted and the strength of the beam concrete was confirmed, the PC steel rod was tensioned to introduce a compressive prestress into the concrete beam and to treat the tensile stress generated in the concrete.

(Problems to be Solved by the Invention) In the above-mentioned conventional method, special machines, tools and parts are required to introduce prestress into the beam, and the work is performed after the concrete strength is confirmed. It was getting longer.

The present invention has been proposed in view of the problems of the prior art described above, and the object thereof is to eliminate the need for machines, instruments, and parts for introducing prestress on site, thereby improving workability, and Is to provide a reinforced concrete structure that is shortened.

(Means for Solving the Problems) In order to achieve the above-mentioned object, a reinforced concrete structure according to the present invention includes a rod-shaped or plate-shaped member having an inverted trapezoidal cross section at a portion where a tensile stress occurs in the reinforced concrete structure. Prestress is introduced via the PC steel material arranged in the direction, a cotter is provided on the upper surface of the member, and a reinforcing bar is buried in the member in a direction perpendicular to the longitudinal direction thereof, and Both ends are protruded from the side surface of the member, and a prestressed precast concrete member having a fixing portion for concrete formed at the protruding end is embedded.

(Operation) According to the present invention, as described above, a prestressed precast concrete member is manufactured in advance, and the member is embedded in a portion of the reinforced concrete structure where a tensile stress is generated, whereby the member is formed of a reinforcing steel. Demonstrates mechanical performance as an alternative, reduces the number of reinforcing bars,
The occurrence of cracks in concrete can be prevented.

Thus, since the prestressed precast concrete member is formed in an inverted trapezoidal cross section and a cotter is provided on the upper surface, the reinforcing bars are integrally connected to the reinforced concrete structure and protrude from the side surface of the member. The prestressed precast concrete member is integrated with the reinforced concrete structure by forming the fixing portion at the protruding end.

(Example) Hereinafter, an illustrated example in which the present invention is applied to the construction of a reinforced concrete beam will be described.

As shown in FIG. 3 and FIG.
A rod-shaped or plate-shaped prestressed precast concrete member (2) having an inverted trapezoidal cross-section is previously produced at a PC factory.

In the drawing, (3) is a sheath buried in the longitudinal direction of the member (2), (4) is a PC steel rod inserted through the sheath (3),
Prestress is introduced into the member (2) via the PC steel rod (4).

(5) is a reinforcing bar buried in the member (2), and both ends of the reinforcing bar (5) protrude outward from both side surfaces of the member (2).

FIGS. 5 and 6 show another embodiment of the prestressed precast concrete member (2), in which PC steel members (4) are vertically arranged.

Thus, when constructing the reinforced concrete beam, after assembling the beam formwork between the columns (A), the member (2) is installed at the center of the lower end of the beam, and the beam main reinforcement (6) and the rib reinforcement (7). And reinforced concrete beams (B) are constructed by placing beam concrete (8).

At this time, the member (2) is formed in an inverted trapezoidal cross section, and the cotter (1) is provided on the upper surface.
The reinforcing bar (5) integrally connected to the beam concrete (8) and projecting from the side surface of the member (2) is fixed in the beam concrete (8), so that the member (2) is reinforced concrete beam. (B) and integrated.

 (C) in the figure is a floor.

Since the illustrated embodiment is configured as described above,
The prestressed precast concrete member (2) exerts a mechanical function as a substitute for a tensile bar in the reinforced concrete beam (B), reduces the amount of the reinforcing bar, and prevents concrete from cracking due to tensile stress.

(Effects of the Invention) According to the present invention, as described above, a prestressed precast concrete member is manufactured in advance, and the member is embedded in a portion of a reinforced concrete structure where a tensile stress is generated, thereby providing the prestressed precast concrete. The member exhibits the performance as a substitute for a tensile reinforcing bar in a reinforced concrete structure, reduces the amount of reinforcing bars, and prevents concrete from cracking.

Further, the cross section of the prestressed precast concrete member is an inverted trapezoidal cross section, a cotter is provided on the upper surface, and a reinforcing bar is buried in a direction orthogonal to the longitudinal direction of the member, and the reinforcing bar projects from the side surface of the member. By providing a fixing portion for the reinforced concrete structure in the portion provided, the member and the reinforced concrete structure are integrated.

[Brief description of the drawings]

FIG. 1 is a partially longitudinal front view showing an embodiment in which the present invention is applied to a reinforced concrete beam, FIG. 2 is a longitudinal side view thereof, and FIG.
FIG. 4 is a longitudinal sectional front view of a prestressed precast concrete member, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, FIG. 5 is a partial longitudinal sectional front view showing another embodiment of a prestressed precast concrete member, FIG. The figure shows the view VI-VI in FIG.
FIG. (B) ... Beam, (1) ... Kotter, (2) ... Prestressed precast concrete member, (4) ... PC steel bar, (8) ... Beam concrete.

Claims (1)

(57) [Claims] 1. A pre-stress is introduced into a portion of a reinforced concrete structure where a tensile stress is generated via a PC steel material disposed in a longitudinal direction of a rod-shaped or plate-shaped member having an inverted trapezoidal cross section, and said member is formed. A cotter is provided on the upper surface of the member, and a reinforcing bar is buried in the member in a direction perpendicular to the longitudinal direction thereof, and both ends of the reinforcing bar project from the side surface of the member, and a fixing portion for concrete is formed at the protruding end portion. A reinforced concrete structure comprising a prestressed precast concrete member embedded therein.