JPS5837461B2 - Pre-cast concrete construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for joining a frame using hollow precast concrete columns (hereinafter referred to as '95' Ca columns).

As a construction method for buildings with RC structure and SRC structure,
A prefabricated construction method using precast concrete members is known.

However, even in the case of prefabricated construction, the columns were almost always made of cast-in-place concrete IJ-contact, and the usual structure was to use precast concrete IJ-members only for the beams. It is.

As a technology for constructing precast concrete members including columns, the specification of Utility Model Application No. 146359/1983 (71852/1983) describes a lightweight and highly useful hollow precast concrete member manufactured using a centrifugal force manufacturing method. The idea related to this is described.

Also, Japanese Patent Application No. 141906/1982 (Japanese Patent Application No. 51-676)
No. 20) specification describes an invention relating to a construction method for assembling a single-column beam frame using lightweight and strong hollow PCa columns.

However, the technical difficulty of constructing a single-column beam frame constructed from precast concrete members lies in how to obtain reliability in the structural strength and rigidity of the joints of the frame.

An object of the present invention is to provide a method for easily and quickly joining a frame using hollow PCa columns, and also in a manner that is sufficiently strong and highly reliable.

In other words, the joining of frames using precast concrete members must, of course, be sufficiently strong and have high structural reliability, but the mission of prefabricated construction is to create a method that can be joined quickly with easy work. It is required that

In this regard, the method of joining a frame using hollow PCa columns described in JP-A No. 50-85118 is to provide steel pipes vertically through the ends of the PCa beams, and to connect the upper and lower hollow PCa columns.
Insert the main column reinforcement of column a into the steel pipe, inject and fill the steel pipe with mortar, interpose an interposition plate between the beam and the column, and insert the steel pipe into the steel pipe insertion hole of the interposition plate. It is characterized by fitting, and has the following drawbacks.

First, the frame assembly work must be performed at least on the upper and lower PCa.
During the curing period until the mortar in the steel pipe into which the main reinforcement of the column is inserted develops a certain level of strength, the work must be stopped and the work lacks speed.

Second, the transmission of axial force between the main column reinforcements of the upper and lower PCa columns, especially the transmission of tensile axial force, is essentially dependent on the bonding effect between the mortar filled in the steel pipe and the column main reinforcements. It lacks structural integrity, lacks reliability, is inferior in strength, and cannot be fully trusted.

The present invention aims to solve the above-mentioned drawbacks of the prior art.

That is, the gist of the structure of the present invention is to connect the ends of the PCa beams by placing them on the support fittings at the upper ends of the hollow PCa columns, and
The connecting fitting on the upper surface of the end of the beam is connected to the lower end of the upper PCa column, and the vertical bars of the upper and lower PCa columns are connected using mechanical connectors, and the main bars of the PCa beam are bent in an L shape. The method of joining a frame consists of the steps of inserting the PCa column into the hollow part of the PCa column and pouring concrete therein.

In this invention, the supporting metal fitting and the hollow PCa column or PCa
The connection to the beam will be firmly established using pre-prepared anchor bolts or inserts.

In addition, the vertical reinforcements of the upper and lower hollow PCa columns can be reliably joined by so-called mechanical connectors that achieve the purpose of joining by mechanical force, such as squeeze joints, and in particular, can transmit tensile axial force. Do it firmly.

The present invention will be explained below with reference to illustrated embodiments.

FIGS. 1 and 2 show a state immediately before a column and beam frame composed of precast concrete members is assembled based on the joining method of the present invention and concrete is poured.

The PCa beams 1, 1 are constructed by placing their ends on support metal fittings 3, 3 firmly attached to the side surface of the upper end of the hollow PCa pillar 2, and the PCa beams 1, 1 and the support metal fittings 3, 3 are strongly connected.

The supporting metal fitting 3 having an L-shaped cross section is fixed in such a manner that its horizontal surface part receives the end of the PCa beam 1 by means of an anchor bolt or an insert prepared in advance on the side surface of the upper end of the hollow PCa column 2. The load applied to 1 is a hollow PC.
It is installed to the a pillar 2 so that it can be transmitted safely.

Further, the PCa beam 1 is integrally and firmly connected to the support fitting 3 by an anchor bolt or an insert prepared in advance on the side surface of the end portion thereof.

The upper hollow PCa column 4 is
It is built on Ca beams 1, 1, and its lower end is built on PCa beams 1, 1.
The center guard Ca pillar 4 and the support fittings 5, 5 are firmly connected by contacting the vertical surfaces of the support fittings 5, 5, which are firmly attached to the upper surface of the end portion of the pillar 1.

The supporting metal fittings 5, 5 having an L-shaped cross section are connected by means of anchor bolts or inserts prepared in advance on the upper surface of the end of the PCa beam 1, so that the vertical surface thereof faces the side surface of the lower end of the upper hollow PCa column 4. and is mounted in a position to receive it.

In addition, the upper hollow PCa column 4 transfers the load to the upper hollow PCa column 4 by means of anchor bolts or inserts prepared in advance on the side surface of its lower end.
It is connected to supporting metal fittings 5, 5 so that it can be safely transmitted to the lower hollow PCa column 2 via the beam 1.

Next, the upper and lower hollow PCa pillars 2 and 4 connect their opposing vertical bars 6 to each other by a connection AX that allows mutual transmission of axial force.

The vertical reinforcements 6... are connected to the formwork 10 shown in FIG. Insert your hand through the opening where it is to be installed.

In particular, in order to quickly, reliably, and firmly join the longitudinal bars 6, 6 together, mechanical connections that achieve the purpose of joining by mechanical force, such as squeeze joints, and in particular, enable the transmission of tensile axial force. Using the tool 7, the vertical bars 6, 6 are joined together.

Therefore, its structural reliability is extremely high.

In addition, even if an external force load, vibration, or displacement is applied to the joint immediately after the joint, as long as it is within the allowable limits of the connecting tool, it will not have a negative effect on the joint effect of the frame.

Therefore, the next frame joining step can be carried out immediately after the vertical reinforcements 6, 6 are joined.

Furthermore, the main reinforcing bars 8 of the PCa beam 1 are bent into an L shape at the portions protruding from the ends of the PCa beam 1, and inserted into the hollow portions 9 of the upper and lower hollow PCa columns 2 and 4, Take measures to make the anchor work.

This step is performed by bending all the main reinforcements 8 into an L shape before constructing the PCa beam 1.

However, when using a machine that can easily bend the main reinforcements 8 and insert them into the hollow part 9, the PCa beam 1
It is also possible to perform this as a step after the construction.

Next, the formwork 10 is attached to the openings that occur at the column-beam joints in the above structure, for example, the openings between the beams at the four corners of the columns, as shown in FIG.
− Seal off to prevent water from flowing.

Also, a formwork 11 is installed inside the hollow part 9 of the lower hollow PCa column 2 to cross and partition the hollow part 9.

This formwork 11 is constructed by bending reinforcing bars or suspending it using supporting metal fittings, so that the lower hollow P
It is attached to the Ca column 2 in advance.

The installation position should be set to a depth necessary and sufficient (hollow (depth from the top of PCa column 2).

It is also possible to cast concrete IJ-t in the entire hollow part 9 of the hollow PCa column 2 and fill the hollow part 9 with concrete IJ-t, but from the viewpoint of obtaining structural joint strength and rigidity of the frame. This is because it is unnecessary and uneconomical.

The process of pouring concrete IJ in the area limited by the formworks io and ii as described above is performed by placing the upper hollow PCa column 4
This is done by dropping the mortar concrete IJ-trough 12 through the hollow part 9 of the container.

As shown in FIG. 3, mortar concrete 12 is cast in a limited space above formwork 11 to a height that extends slightly above the upper end of the upwardly bent main reinforcement 8 of PCa beam 1. Then, use a pie break, etc. to thoroughly tamp the concrete and place it with a high degree of density.

All steps of the joining method of the present invention are completed with the step of curing the mortar concrete IJ-N2 thus cast until it develops its strength.

The formwork 10 is removed after the mortar concrete IJ-N2 is cured.

In addition, if there is a possibility that the upper and lower hollow PCa columns 2, 4 have insufficient cross-sectional area for the axial force (vertical load) applied thereto, as shown in an example in Fig. 4, a It is effective to add reinforcing beams 13 that cross in a cross shape.

Note that the cross-sectional shape of the hollow PCa pillars 2 and 4 is not limited to the illustrated rectangle.

The joining method of the present invention is carried out as described above, and has the following special effects.

First, since the hollow PCa columns and PCa beams are bolted to each other via supporting metal fittings, they can be firmly and reliably joined, making it possible to construct a frame with extremely high structural reliability. can.

Second, the vertical reinforcements of the upper and lower hollow PCa columns are firmly and reliably connected to each other by mechanical connectors, allowing the mutual transmission of axial force (especially tensile axial force), so the reliability of the joining effect is high. The strength of the joints is extremely high, and the strength of the joints in the frame is extremely high, making the structure highly reliable.

Furthermore, even if an external force load, vibration, or displacement is applied to the joint immediately after the joint, as long as it is within the allowable limits of the connecting device, it will not have a negative effect on the joint effect of the frame, so the next step can be carried out immediately. It is possible to proceed with the joining process of the frame.

Therefore, the work process can be completed quickly, which in turn contributes to shortening the construction period.

Thirdly, the work of bolting the hollow PCa columns and PCa beams together via support fittings, and the work of joining the vertical bars of the upper and lower hollow PCa columns using mechanical connectors both require skill. First, anyone can easily perform this process and obtain the same joining effect, so in this sense as well, it has high structural reliability and contributes to facilitating the work of joining frames.

Fourthly, as long as the column member is hollow, an existing general hollow PCa column can be used, and there is flexibility in the selection of the member.

[Brief explanation of drawings]

Figure 1 is a partially broken elevation view showing the state before concrete pouring at the joint of a one-beam column frame, Figure 2 is a cross-sectional view of Figure 1, and Figure 3 is a partially broken elevation showing the state before concrete pouring. A partially broken elevation view showing the later joined state, Figure 4 is a hollow PCa
FIG. 3 is a cross-sectional view showing different cross-sectional shapes of columns. 2...Hollow precast concrete column (lower), 3...Supporting metal fittings, 1...Precast concrete beam, 5...Supporting metal fittings, 4...
... Upper hollow precast concrete column, 6.
...Vertical stripes, 7...Connectors, 8...
・Main reinforcement, 9...Hollow section, 12. Hammered/mortar concrete.

Claims (1)

[Scope of Claims] 1. A method for joining a frame using hollow precast concrete IJ-to columns, which adheres to the following (a) to (d). (a) A supporting metal fitting is attached to the side surface of the upper end of the hollow precast concrete column in such a manner that its horizontal surface part receives the beam, and the precast concrete beam is erected with its end placed on the horizontal surface part of the supporting metal fitting. and a step of connecting the precast concrete beam and the support fittings. (b) Attach a supporting metal fitting to the upper surface of the end of the above precast concrete beam in such a manner that its vertical surface receives the side surface of the upper hollow precast concrete column, and then erect the upper hollow precast concrete column so that its lower end is supported. A step of connecting with the support fitting. (c) A process in which the vertical reinforcements of the upper and lower hollow precast concrete columns are connected using mechanical connectors that enable mutual transmission of axial force. (d) The main reinforcement of the precast concrete beam is bent into an L shape and inserted into the hollow part of the hollow precast concrete column, filling at least all of the main reinforcement bent into the L shape in the hollow part of the upper and lower hollow precast concrete columns. Step of pouring concrete IJ in the area.