JP3156014B2 - Precast reinforced concrete frame with end steel joints - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast reinforced concrete member (hereinafter referred to as a PCa member) for columns and beams.
PCa members related to a precast reinforced concrete frame (hereinafter, referred to as PCa frame) integrated by site welding of end steel frames, which is carried out in the construction of a building or the like constructed by a prefabricated construction method using.

[0002]

2. Description of the Related Art Conventionally, middle and low-rise buildings have generally been constructed of reinforced concrete (hereinafter referred to as RC) mainly for on-site construction. RC construction is economical, but has drawbacks in that it is inferior in strength to steel frame construction (hereinafter referred to as S construction) and poor in workability. Therefore, in recent construction of high-rise and high-rise buildings, S-structures are generally employed. In particular, with the recent shortage of construction workers and the aging of the population, many construction laboratories are developing and adopting many industrialized and prefabricated construction methods for labor saving and building factory production. That is, in RC construction, the P
It is Ca conversion, and on the other hand, it is appearing as a promotion of S structure. Incidentally, with the advent of (ultra) high-strength concrete due to the development of admixtures and casting methods, the drawbacks in the strength aspect of PCa members have been temporarily solved.

[0003]

[Problems to be Solved by the Invention] Construction of high-strength frames and the like of high-rise buildings due to the factory production, labor saving and improvement of on-site construction of PCa members made of the above-mentioned (ultra) high-strength concrete. However, there are great problems to be solved in the joint of the PCa member. For example, due to the recent economic recession, construction costs, which have been rising sharply so far, have been greatly restrained, and competition for cost reduction has intensified more than before. Therefore, there is an urgent need to reduce the use of expensive steel frames and reduce labor costs by saving labor on site. Then, conventional P
Joining by joining anchor bars or main bars, which are generally used for joining Ca members, takes too much time and is problematic in that on-site workability is poor. On the other hand, the method of compounding a PCa member with a steel frame material to form an SRC structure and welding and joining the ends of the steel frame material on site does not respond to cost reduction competition because the PCa member becomes too expensive.

[0004]

As a means for solving the above-mentioned problems of the prior art, a precast reinforced concrete frame with end steel frames joined according to the present invention comprises:
At the upper and lower ends of the molded precast reinforced concrete column, the end plate of the shape and structure equivalent to the diaphragm is threaded to the end of the PC steel bar that replaces the main bar of the column, and the nut is strongly tightened. Pre-stress is introduced by screwing and tightening, and it is connected and integrally attached. The upper and lower precast reinforced concrete columns are joined by welding with steel pipes between the end plates and joined together by welding. At the ends of the precast reinforced concrete beam, the end steel frame is also threaded into the end of the PC steel bar in place of the main bar of the beam, and the nut is strongly screwed in and tightened. The precast reinforced concrete beam is end-connected to the precast reinforced concrete beam material by applying stress and being integrally attached. Respectively, characterized in that it is assembled engages against the steel Joint part consisting of end plates and steel pipe of Nkurito pillar.

[0005]

[0006]

The end plate 2 of the PCa column 1 and the steel frame 6 of the PCa beam 5 are each formed with the minimum necessary amount of steel frame, so that the material cost burden is light. Since the PCa column members 1 and 1 and the PCa column member 1 and the PCa beam member 5 are joined by on-site welding of steel members, on-site workability is good, which contributes to labor saving and shortening the construction period.

When prestress is introduced into the column 1 and the beam 5 through the PC steel bar, the PCa column 1 and the PCa beam 5
The respective strengths are improved, and the integration of the end plate 2 and the end steel frame 6 and the mounting strength are improved. And PC
Since the hinge zone at the end of the beam member 5 is made of steel, the frame has excellent mechanical properties and excellent toughness.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The PCa frame shown in FIG. 1 to FIG. 3 is formed on the upper and lower ends of the PCa column 1 manufactured by RC using a (ultra) high-strength concrete, for example, by a centrifugal molding method. An end plate 2 having a shape and a structure (refer to FIG. 2) corresponding to a diaphragm frequently used for beam-to-column connection is attached, and upper and lower PCa column members 1, 1 are located between the end plates 2, 2. The steel pipes 4 are interposed and joined by welding between steel frames to be integrated. The end plate 2
Is abutted on the end surface of the molded PCa column member 1 in close contact with the outer surface of the main bar 3 of the PCa column member 1, and the nut 7 is screwed in and strongly fastened to be integrally attached. (See FIG. 3). Therefore, this PCa column material 1 is configured as a column piece in which the column shaft portion is made of RC and the beam joint portion is made of S and is completely integrated. As the steel pipe material 4, a rectangular steel pipe or a circular steel pipe similar to the cross-sectional shape of the column shaft portion is used in order to treat the vertical load and the bending load (horizontal load) applied to the column with equal strength. As shown in FIG. 3, the material 4 is formed to have a proper length for joining a steel connection member of a beam material.

[0009] Next, the PCa beam 5 is also manufactured as an RC structure by centrifugal molding using (ultra) high-strength concrete, and as a process after molding, steel frames 6 are attached to both ends, and this end is formed. The flange portion of the steel frame 6 is joined to the end plate 2 by field welding, and the web portion is made of steel pipe material.
4 and a bolt and a nut . The steel frame 6 is brought into contact with the plate 6a in a state where the plate 6a is in close contact with the end face of the formed PCa beam member 5, and P
The outer end of the main bar 8 of the Ca beam member 5 is threaded to form a nut 7
Are screwed into each other and fastened together (see FIG. 3). Therefore, this PCa beam member 5 is also configured as a beam piece in which the connection portion is made of S and the beam shaft portion is made of RC. And this PCa beam member 5 can be attached to the PCa column member 1 in exactly the same manner as joining a conventional S beam member to an S column, and the strength and workability are the same as those of the S column. In fact, a PCa frame that is substantially as inexpensive as a RC structure can be constructed.

The end plate 2 of the PCa column 1 and the steel frame 6 of the PCa beam 5 are each replaced with the main reinforcing bar 3 or 8 by using a PC steel rod. By introducing an appropriate prestress into the member 1 and the beam member 5, the strength of the PCa column member 1 and the PCa beam member 5 can be increased, and the degree of integration of the end plate 2 and the steel frame 6 can be improved.

[0011]

[Effects of the present invention] The precast reinforced concrete frame according to the present invention by joining the end steel frames has the following effects. Efficient use of the steel frame reduces the cost of using the steel frame and achieves cost reduction.

The pillars, their joints, and beams are all prefabricated in the factory, and the on-site joining is at the steel frame, so that labor saving and on-time reduction of on-site construction are achieved. Since the hinge zone at the end of the beam is a steel frame, the frame has excellent mechanical properties and excellent toughness.

[Brief description of the drawings]

FIG. 1 is a front view of a PCa frame.

FIG. 2 is a plan view of a PCa frame.

FIG. 3 is an enlarged front view of a beam-column joint.

FIG. 4 is a sectional view taken along arrow 4-4 in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PCa column material 2 End plate 3 Column main bar 4 Steel pipe material 5 PCa beam 6 Steel frame 8 Beam main bar

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) E04B 1/20-1/21 E04B 1/30

Claims (1)

(57) [Claims] 1. An end plate having a shape and a structure corresponding to a diaphragm is formed on upper and lower ends of a precast reinforced concrete pillar formed by threading an end of a PC steel bar in place of a main reinforcement of the pillar. The pre-stressed reinforced concrete columns are connected and integrally attached by introducing prestress by strongly screwing and tightening the nuts, and the upper and lower precast reinforced concrete columns are welded by interposing a steel pipe between the end plates. At the both ends of the precast reinforced concrete beam, the end steel frame is also threaded into the end of the PC steel bar instead of the main bar of the beam, and the nut is screwed in strongly. The end steel frame of the precast reinforced concrete beam material, which is pre-stressed by being fastened and combined and integrally attached,
The precast steel Joint part consisting of end plates and steel pipe of reinforced concrete pillar and assembled engaged against each characterized by being, precast reinforced concrete Frames by joining end steel.