JP2852166B2 - Method for preventing freezing of grout material during PC member installation bonding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing a grout material from being frozen when a PC member is installed in a cold region.

[0002]

2. Description of the Related Art For example, a plurality of reinforcing bars extend inside a PC member such as a pillar, and in many cases, the ends of these reinforcing bars are inserted into a sleeve embedded in the end of the PC member. Have been. And when installing the PC member,
Inserting a reinforcing bar protruding from the mounting portion into the sleeve, filling the sleeve with a grout material after the insertion, and curing the grout material to bond the reinforcing bars together, thereby securing the bonding strength between the reinforcing bars. I have to.

On the other hand, the grout material filled in the sleeve must be maintained at a predetermined temperature, for example, 0 ° C. or higher, until it is cured. Therefore, especially when the installation work of the PC member is performed in a cold region, simply injecting the grout material into the sleeve will freeze the grout material without hardening, and it is difficult to secure the bonding strength between the reinforcing bars. For this reason, in a cold region, conventionally, a method of covering the entire construction site filled with the grout material with a sheet, or covering a portion filled with the grout material with a blanket or a heat insulating material has been adopted.

[0004]

However, the method of covering the entire construction site filled with the grout material with a sheet requires a great deal of labor and cost, and it is not easy to control the temperature. Further, the method of covering the portion filled with grout with a blanket or a heat insulating material cannot be adopted in a region where the outside air is extremely low because the heat insulating effect of the heat insulating material is limited. The present invention has been devised in view of the above circumstances, and it is an object of the present invention to reliably prevent the grout material from freezing by a simple method and to improve the efficiency of installation work of PC members in a cold region. It is an object of the present invention to provide a method for preventing freezing of a grout material at the time of PC member installation bonding.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a sleeve embedded in an end of a PC member into which an end of a reinforcing bar extending inside the PC member is inserted.
Insert the reinforcing bar protruding from the mounting position of the PC member,
When the grout material is filled in the sleeve and cured, the two reinforcing bars are joined to each other, and when the PC member is installed at the mounting position, a heating element that generates heat by energizing the sleeve is wound inside the PC member. When the temperature of the PC member on which the sleeve is located falls below a predetermined value, power is supplied to the heating element.

Further, according to the present invention, the end of the reinforcing member is embedded in the end of the PC member, and the end of the reinforcing bar extending inside the PC member is inserted into the sleeve into which the end of the reinforcing member is inserted. By inserting a reinforcing bar, filling the grout material in the sleeve and curing the same, the two reinforcing bars are joined, and when the PC member is installed at the mounting location, the power is supplied around the PC member where the sleeve is located. A heating element that generates heat is wound, and when the temperature of the PC member on which the sleeve is located falls below a predetermined value, power is supplied to the heating element.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment applied to a PC member installation work in a cold region will be described below with reference to the accompanying drawings. FIG.
FIG. 2 is a side view when a PC member is installed on a building frame by the method according to the first embodiment, and FIG. 2 is a plan view of the same. Reference numeral 1 denotes a building frame, and 3 denotes a PC member forming a pillar. Nine reinforcing bars 5 extend in the PC member 3 along the longitudinal direction of the PC member 3. Nine sleeves 7 are embedded in the ends of the PC member 3 corresponding to the reinforcing bars 5, and the ends of the respective reinforcing bars 5 are inserted into the upper half of the sleeve 7. Nine reinforcing bars 11 protrude from the building frame 1 corresponding to the reinforcing bars 5, and each reinforcing bar 11 is inserted into the lower half of the sleeve 7.
The two reinforcing bars 5 and 11 are joined together in the sleeve 7 by the grout material G filled therein, and a number of PC members 3 are installed on the building frame 1 by such a method.

FIGS. 3A and 3B are cross-sectional views of various sleeves 7. As shown in FIG. 3 (A), the sleeve 7 has a space in which the grout material G is filled up and down, or is formed as shown in FIG. 3 (B). The spiral protrusion 501 of the reinforcing bar 5 on the side of the building and the spiral groove 701 on the side of the sleeve 7 are connected to each other, and
There are various types such as a grout filling space formed only in the lower half portion for joining the grout, and two sleeves 703 for grout filling generally have upper and lower portions of the space in the sleeve 7. It is provided so that it may communicate with.

In the first embodiment, as shown in FIG.
Heating elements 13 such as nichrome wires are wound around the outer circumferences of the nine sleeves 7 of the C member 3, respectively, and the heating elements 13 of each sleeve 7 are connected to each other by lead wires 15 (see FIG. 2).
The lead 15 is drawn out of the PC member 3. The wiring of the heating element 13 and the lead wire 15 is performed in advance when the PC member 3 is manufactured. As shown in FIGS. 1 and 2, a temperature sensor 17 such as a thermocouple or a thermistor is attached to a location near the sleeve 7 on the surface of each PC member 3. Reference numeral 19 in the figures denotes a lead wire.

[0010] As shown in FIG. 5, a control panel 21 is disposed at an appropriate position of the building frame 1. In the control panel 21,
An energizing circuit 25 for turning on / off the power supply from the commercial power source 23 to the heating element 13 and an energizing control circuit 27 for controlling the on / off operation of the energizing circuit 25 are provided. The energizing circuit 25 includes a number of Ps installed on the building frame 1.
Each of the lead wires 15 drawn from the C member 3 is connected. Further, the lead wires 19 drawn out from a number of PC members 3 installed on the building frame 1 are connected to the power supply control circuit 27.

When the power supply control circuit 27 determines that the temperature near the sleeve of the PC member 3 is, for example, 0 ° C. or less based on a signal from the temperature sensor 17, the power supply circuit 25
To the corresponding heating element 13 of the PC member 3 by connecting the lead wire 15 to the commercial power source 23 via the
When it is determined that the temperature in the vicinity of the sleeve 7 is, for example, 5 ° C. or more, the power supply to the heating element 13 of the corresponding PC member 3 is cut off, and thus a large number of PCs
The temperature near the sleeve of the member 3 is centrally controlled.

According to this embodiment, when the reinforcing bar 5 on the PC member 3 side and the reinforcing bar 11 on the building frame 1 side are joined with the grout material G filled in the sleeve 7 in a cold region, the lead wire of the heating element 13 is used. If the operation of connecting the 15 to the control panel 21 and the operation of attaching the temperature sensor 17 to three PC members near the sleeve 7 are performed, the temperature of the grout material G in the sleeve 7 is always maintained at a certain value or more. Thus, the grout material G can be surely cured. Therefore, it is possible to eliminate the troublesome work of covering the entire work place filled with the grout material G with a sheet or covering the place filled with the grout material G with a blanket or a heat insulating material, and to install the PC. Member 3
Even if there are many, the freezing of the grout material G can be reliably prevented by a simple operation, and the efficiency of the installation work of the PC member 3 in a cold region can be improved.

The environment in which the PC member 3 is installed by changing the pitch of the heating element 13 wound around the sleeve 7, the diameter of the heating element 13, or the voltage value applied to the heating element 13 or the like. The heating temperature can be arbitrarily controlled depending on the situation.

Next, a second embodiment will be described. FIG.
FIG. 7 is a side view when the PC member is installed on the building frame by the method according to the second embodiment, and FIG. 7 is a plan view of the same. In the second embodiment, the heating element 13 is wound around three PC members in which the sleeve 7 is embedded. Different from the first embodiment. That is, a heating element 13 such as a nichrome wire is wound around three places of the PC member in which the sleeve 7 is embedded, and the lead wire 15 connected to the heating element 13 is connected to the energizing circuit 25 as described above.

A temperature sensor 17 such as a thermocouple or a thermistor is attached to the surface of each PC member 3 in the vicinity of the sleeve 7, and the temperature sensor 17 is connected to the power supply control circuit 27 by the lead wire 19 in the same manner as described above. Connected to. In the same manner as in the first embodiment, the power supply from the commercial power supply 23 to the heating element 13 is controlled on / off based on the temperature detected by the temperature sensor 17, and the sleeves 7 of the many PC members 3 are controlled.
The temperature of the nearby location is centrally controlled.

[0016]

As is clear from the above description, the present invention
A rebar protruding from a mounting portion of the PC member is inserted into the sleeve into which the end of the rebar embedded in the end of the PC member and extending inside the PC member is inserted, and inserted into the sleeve. When the grout material is filled and hardened to join the two rebars, and when the PC member is installed at the mounting location, a heating element that generates heat by energizing the sleeve inside the PC member is wound, and the sleeve is PC located
When the temperature of the member falls below a predetermined value, the heating element is energized, or the heating element that generates heat by energizing is wound around the PC member where the sleeve is located, and the sleeve is wound. When the temperature of the PC member in which is located falls below a predetermined value, the heating element is energized, so that the temperature of the grout material can be maintained at a predetermined value by a simple method and its freezing can be reliably prevented, and It is possible to improve the efficiency of installation work of PC members on the ground.

[Brief description of the drawings]

FIG. 1 is a side view when a PC member is installed on a building frame by a method according to a first embodiment.

FIG. 2 is a plan view when a PC member is installed on a building frame by the method according to the first embodiment.

FIGS. 3A and 3B are cross-sectional views of a sleeve.

FIG. 4 is a side view of a sleeve around which a heating element is wound.

FIG. 5 is a control block diagram of a heating element.

FIG. 6 is a side view when a PC member is installed on a building frame by a method according to a second embodiment.

FIG. 7 is a plan view when a PC member is installed on a building frame by a method according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Building frame 3 PC member 5,11 Reinforcing bar 7 Sleeve 15,19 Lead wire 17 Temperature sensor 21 Control panel 23 Commercial power supply 25 Electric circuit 27 Electric control circuit G Grout material

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E04G 21/12 104

Claims (2)

(57) [Claims] 1. A rebar protruding from a mounting position of a PC member is inserted into a sleeve embedded in an end portion of the PC member and into which an end portion of a rebar extending inside the PC member is inserted. When the grout material is filled in the sleeve and hardened to join the two rebars, and when the PC member is installed at the mounting location, a heating element that generates heat by energizing the sleeve inside the PC member is wound. And turning on the heating element when the temperature of the PC member on which the sleeve is located falls below a predetermined value, wherein the grout material is prevented from being frozen at the time of PC member installation joining. 2. A rebar protruding from a portion to which the PC member is attached is inserted into a sleeve which is embedded in an end of the PC member and into which an end of a rebar extending inside the PC member is inserted. When the grout material is filled in the sleeve and cured, the two reinforcing bars are joined to each other, and when the PC member is installed at a mounting location, a heating element that generates heat by energizing around the PC member where the sleeve is located is provided. And winding the heating element when the temperature of the PC member on which the sleeve is located falls below a predetermined value. The method for preventing freezing of a grout material at the time of PC member installation joining.