JPH10147978A - Vertical member joining and erecting method for precast reinforced concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a form arranged in a joint space by using a simultaneous filling work as one of the methods of jointing and erecting a PC (precast reinforced concrete) column member to a lower structure. SOLUTION: A PC column member 1 in which a sleeve joint 5 is embedded at the lower end is built on a lower structure 3 to form a joint space. A rubber tube 8 is arranged along the peripheral edge of the joint space, inflated by air blown from a blow port 9 and adhered to the lower end peripheral edge of the column member and the upper face of the lower structure to close the joint space. Then, grout 11 is filled from a joint filling port 6, where only one of a number of embedded joints 5 is open to the side wall of the column member, to cover the joint space and all embedded joints. In this way, a form is more easily arranged at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting a precast reinforced concrete vertical member typified by a column member to a lower structure, and the method is called a simultaneous injection method. The present invention relates to an improvement in a method of erecting a joint.

[0002]

2. Description of the Related Art As a method of connecting a main member of a vertical member of precast reinforced concrete (hereinafter referred to as PC) represented by a column member to a vertical member of a lower structure by joining the main member of the lower member to the lower structure. There is a method using a sleeve type reinforcing steel joint buried in the lower end portion of the member, and as an improvement method thereof, a joint standing method called a simultaneous injection method is disclosed in Japanese Patent Publication No. 4-52815. .

[0003] The rebar joint has two opposing rebar anchoring means, and a pair of rebars are butt-joined by fixing the ends of the pair of rebars to be joined thereto. There are various types of fixing means, one of which is a sleeve mortar type fixing means. This is a fixing means of a method in which an end of a reinforcing bar is inserted into a cylindrical body called a sleeve, and the reinforcing bar is fixed in the sleeve by hardening a grout (mortar having a high fluidity) filled in the sleeve. All the two fixing means are joints of the sleeve mortar type (having the shape of a single cylinder) are called mortar-filled rebar joints or sleeve joints, and one is the same type and the other is the other fixing means (screw type) Etc.) is referred to as a half-sleeve joint, and the case where this is a screw-in type is referred to as a threaded-sleeve joint. The sleeve joint and the half sleeve joint are collectively called a sleeve joint. An inlet and an outlet are provided on the side wall near both openings of the sleeve joint,
An inlet is provided near the opening of the sleeve portion of the half-sleeve joint, and an outlet is provided near the boundary with other fixing means.

[0004] A typical conventional simultaneous injection method is described with reference to FIG. 2 (longitudinal section). In the figure, a sleeve joint is used as a sleeve type joint, and a PC column member is used as a PC vertical member. A plurality of sleeve joints 5 are buried in the lower end of the PC column member 1 in the vertical direction, and the lower opening thereof is open to the lower end surface of the member. The lower ends of the plurality of member main reinforcing bars 2 are inserted into the sleeve joint and connected to each other, and the lower end thereof reaches almost the center of the joint. Discharge ports 7 are provided in the side wall near the upper opening of the buried joint 5, and open to the member side wall. Of the plurality of buried joints 5, only the inlet 6 of a specific joint (usually one) is open to the side wall of the member, but the inlets of the other buried joints are closed and open to the side wall of the member. Absent.

The lower structure 3 is generally a structure in which a beam member, a floor member and the like are connected to a lower column member capital, and an upper end portion of a vertical main reinforcing bar 4 protrudes from the upper surface by a predetermined length. The projecting end of the vertical main reinforcing bar 4 is generally the end at which the lower column member main reinforcing bar penetrates a beam member or the like connected to the member capital. In addition, the lower main structure vertical main reinforcement 4 and PC
The column member main rebar 2 is at a corresponding position where it can be butt-joined. Although not shown for the sake of simplicity, a number of annular projections are provided on the inner wall surface of the sleeve of the sleeve type joint to strengthen engagement with the hardened grout.

[0006] The PC column member 1 must be correctly erected vertically and installed so that joint mortar is interposed between the PC column member 1 and the lower structure. For this reason, a liner (not shown) having a height equivalent to the joint thickness is placed in the position where the PC column member is to be built, and the PC column member is placed thereon to perform vertical adjustment. At this time, the upper ends of the lower structures projecting above the vertical main reinforcing bars 4 are respectively accommodated in the buried joints 5 at the corresponding positions, and the upper and lower main reinforcing bars 2 and 4 face each other at the joint substantially at the center position. As a result, a joint space having a predetermined height is formed between the lower end surface of the PC column member and the upper surface of the lower structure.

Next, a formwork 10 is arranged so as to surround the joint space from the outside. The mold 10 is formed by assembling a plurality of mold plates, and is disposed so as to be in close contact with both the side walls of the PC column members and the upper surface of the lower structure.

Thereafter, grout 11 is injected from the injection port (opening on the side wall of the member) 6 of the buried joint. After the grout first fills the joint space, it rises into each of the plurality of buried sleeve joints, fills them, and overflows from the respective outlets 7. Confirm grouting from all outlets and finish grouting. By hardening of the grout, the upper and lower main reinforcing bars 2 and 4 are joined in the buried joint 5, and the PC column member is joined and erected on the lower structure.

When a half-sleeve joint is used, the sleeve portion is buried so as to be located below and the sleeve portion is opened at the lower end surface of the member, while the lower end portion of the main reinforcing bar of the member is attached to another fixing means located above. Establish and combine.

In the conventional joint erecting method prior to the simultaneous injection method, in the above-mentioned process, after temporarily placing a PC column member on a liner and temporarily installing the member, the member is once returned to an upper position, Apply joint mortar to joint space with mortar,
The C column members are lowered again to perform the main construction. Then, grout is injected one by one from an injection port provided in each of the plurality of buried sleeve joints. Since the lower opening of the buried joint is not closed by the joint mortar constructed earlier and is not in communication with the joint space, grout must be individually injected into the joint.

[0011]

The simultaneous pouring method can omit the joint mortar construction step and can complete the grout pouring into a plurality of buried joints in one step as compared with the above-mentioned conventional joint erecting method. The benefits are great. However, there is a problem in the process of disposing the formwork around the joint space. That is, the mold must be in close contact with both the PC column member side wall and the upper surface of the lower structure, and since the outlet of the buried joint is located considerably above, the grout injection pressure is high, and grout is generated from the mold. The closeness must be high to prevent leakage. In particular, a high degree of closeness between the formwork and the upper surface of the lower structure is difficult to achieve, which requires a special construction of the formwork. As described above, if there is a high degree of compatibility between the size and shape of the column member and the mold used therein, it is necessary to prepare a mold suitable for each PC column member of each size and shape. In addition, the trouble of assembling and removing the formwork is complicated.

[0012]

According to the present invention, a mold tube having high flexibility such as a rubber tube is provided instead of a mold formed by assembling a mold plate conventionally used as a mold in the simultaneous injection method. This solves the above problem.

According to the present invention, there is provided (a) a precast reinforced concrete vertical member (hereinafter referred to as a PC vertical member) having a plurality of sleeve-type joints opened at a lower end thereof at a lower end surface thereof and a lower end of the main reinforcing bar of the member. All the outlets of the plurality of buried joints are open to the side wall of the member, but the inlet is a structure in which only a specific buried joint is open to the side wall, b) the lower structure is
The upper ends of the plurality of vertical main reinforcing bars protrude from the upper surface by a predetermined length, and when the PC vertical member is erected, the vertical main reinforcing bars respectively abut against the plurality of main reinforcing bars of the member. (C) connecting the PC vertical member with the lower end of the lower surface of the PC vertical member and the upper surface of the lower structure. (D) A flexible tube made of a flexible and air-tight material is arranged around the joint space so as to surround the joint space. The tubes are connected at both ends to make the tube an annular sealed state. The tube is expanded by injecting and filling a fluid such as air or water from a blowing port provided on a side wall of the tube to expand the tube so that the lower edge of the PC vertical member has a lower peripheral edge. Yo (E) Then, grout is injected from an inlet opening in the side wall of the specific buried joint to grind the joint space and the sleeves of all the buried joints. After the grout loses its fluidity, the fluid is removed from the form tube to release its expansion and is removed from the joint space. A method for joining and erecting members.

The structure of the PC vertical member, the embedding mode of the sleeve type joint therein, the structure of the lower structure, the mounting mode of the PC vertical member therein, and the like in the present invention are the same as those of the conventional simultaneous injection method. The vertical member refers to a member that stands upright in the vertical direction, such as a column member or a wall member.

The form tube used in the present invention is made of a flexible tube made of a flexible and airtight material. Known materials such as rubber, soft polyethylene, rubberized cloth, fire hose ground, and the like can be used as the material. At both ends of the tube, connection terminals that can be connected to each other are provided, and by setting the connection terminals, the tube can be closed in a ring shape and sealed. Then, when this connection is released, the seal is released and both ends become free and can be used repeatedly.

The connection terminal is usually a male / female fitting type connection tool, which is preferably made of a soft material such as polyethylene rather than a metal. A method of attaching a velcro to the outside of the end of the tube, butting both ends, and then wrapping another piece of velcro tape outside the butt to join both ends together may be adopted. Also, if one end of the tube is made insertable into the other end, the length of the tube can be adjusted. In addition, inexpensive materials such as a polyethylene tube may be joined by a known joining means such as heat sealing or adhesion. In this case, it is only necessary to dispose after use after returning to the original state.

FIG. 1 schematically shows an embodiment of the present invention.
(Longitudinal view) will be described. In the figure, a sleeve joint is used as a sleeve type joint, and a PC column member is used as a PC vertical member. The reference numerals in the figure are the same as those in FIG.

A mold tube (using a rubber tube) 8 having connection terminals at both ends is arranged so as to make one round along the periphery of the joint space while bending, and the connection terminals are set and the tube is closed in an annular shape. Keep in a sealed state. If necessary, set an auxiliary tool (usually easily created by cutting or nailing wood or the like that is available at the site) for adjusting and reinforcing the shape of the frame tube such as the holding frame 12.

Next, the PC column member 1 is installed in the same manner as in the conventional simultaneous injection method. After the installation of the member, a form tube may be provided. After the members are installed, a fluid (generally, air) such as air or water is injected and filled from a blowing port 9 provided on a side wall of the form tube. This causes the form tube to expand to P
The lower end surface of the C column member and the upper surface of the lower structure are pressed together and tightly closed to seal the joint space. In other words, the form tube is formed around the joint space by the form tube to the same effect as the conventional simultaneous injection method.

The blow-in port 9 is a short tube protruding from the side wall of the form tube, and is provided with a check device or a closing device for preventing leakage of the filled fluid. Generally, it is convenient to adopt a structure of an air inlet with a rubber pad of a bicycle tire.

Thereafter, the grout 11 is introduced from the injection port 6 opened on the side wall of the PC column member in the same manner as in the conventional simultaneous injection method.
To grout the joint space and the sleeves of all buried sleeve joints.

After the grout loses fluidity, the fluid is expelled from the form tube to release its expansion and is removed from the joint space. If necessary, fill the tube mark with mortar to shape the joint.

[0023]

The arrangement of the formwork around the joint space according to the present invention has the following advantages as compared with the formwork arrangement by assembling the formwork plate in the conventional simultaneous pouring method. 1. Forming and removing operations are greatly simplified. 2. A high degree of close contact of the formwork with the lower end surface of the PC vertical member and the upper surface of the lower structure can be easily achieved. That is, since the mold tube is rich in flexibility, even if these contact surfaces are rough surfaces, they can closely follow the shape thereof, and because they are pressurized and expanded, the close contact is strong. 3. Since it is possible to flexibly respond to changes in the size and shape of the PC vertical member, there is a great economical advantage that it is not necessary to prepare a mold strictly adapted to the size and shape of the member as in the related art.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view and a plan view schematically showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view and a plan view schematically showing an embodiment of a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PC column member 2 Same as above main reinforcement 3 Lower structure 4 Same as above main reinforcement 5 Sleeve joint 6 Inlet 7 Outlet 8 Form tube 9 Inlet 10 Form 11 Grout 12 Holding frame

Claims (1)

[Claims] (A) In a precast reinforced concrete vertical member (hereinafter, referred to as a PC vertical member), a plurality of sleeve type joints are opened at the lower end thereof and are connected to the lower end of the main reinforcing bar of the member. The outlets of the plurality of buried joints are all open to the side wall of the member, but the inlet is a structure in which only a specific buried joint is open to the side wall. In the lower structure, the upper ends of the plurality of vertical main reinforcing bars protrude from the upper surface by a predetermined length, and these vertical main reinforcing bars correspond to the plurality of main reinforcing bars of the member when the PC vertical member is installed. (C) a structure at a corresponding position so as to form a butted shape;
In the PC vertical member, a vertical reinforcing bar protruding end of the lower structure is accommodated in a sleeve of a buried joint, and a joint space having a predetermined height is formed between a lower end surface of the PC vertical member and an upper surface of the lower structure. (D) A flexible form tube made of a flexible and air-tight material is disposed on the periphery of the joint space so as to surround the joint space, and both ends thereof are connected to form an annular sealed state. The tube is expanded by injecting and filling a fluid such as air or water from a blowing port provided on the tube side wall, and is brought into close contact with the periphery of the lower surface of the PC vertical member and the upper surface of the lower structure to seal the joint space. (E) Then, grout is injected from an inlet opening in the member side wall of the specific buried joint to fill the joint space and sleeves of all the buried joints with grout,
After the grout loses fluidity, a method of joining a precast reinforced concrete vertical member to a lower structure, comprising removing fluid from a form tube to release its expansion and removing it from the joint space.