JP2637899B2 - Manufacturing method of prestressed concrete and prestressed concrete - 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 producing prestressed concrete and a prestressed concrete.

[0002]

2. Description of the Related Art Generally, in prestressed concrete, a tensile force is applied in advance to a PC steel material such as a PC steel rod or a PC steel wire, concrete is poured, and after the concrete is solidified, the tensile force of the steel material is released. The compressive force is applied to the concrete member by the adhesion of the concrete member.

[0003]

However, in such prestressed concrete, when a large tensile force acts on the steel material, the steel material may be corroded and broken when exposed to a corrosive environment. Also, the steel material is heavy, and arranging the steel material in an appropriate place before pouring concrete was a heavy labor for workers.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a prestressed concrete which is hardly corroded even in a corrosive environment and in which steel can be easily arranged at the time of manufacturing, and a method of manufacturing the same. Is to provide.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention comprises a step of bending a carbon fiber reinforced plastic outside a mold and passing the same through a mold a plurality of times; A step of pulling from both sides outside the frame, a step of energizing and curing the carbon fiber reinforced plastic, a step of placing concrete in the formwork, and after the concrete is solidified, the concrete is outside the formwork. And a step of cutting the carbon fiber reinforced plastic, and a prestressed concrete manufactured by the method.

[0006]

The carbon fiber reinforced plastic is lightweight, does not harden before energization, can be easily bent, and its arrangement is easy. Further, after being hardened by energization, corrosion hardly occurs even in a corrosive environment.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings, taking a pretension type prestressed concrete as an example. 1 and 2 are views for explaining a production state of prestressed concrete. FIG. 1 is a plan view and FIG. 2 is a front view.

1 and 2, reference numeral 1 denotes a mold. The tension table 3 is arranged on the floor B so as to be movable on the floor B.
The tension base 3 is provided with a fixing portion 5. The fixing portion 5 has a carbon fiber reinforced plastic 7 (CFRP, Carbon Fiber Rei).
One end of nforced Plastics) is fixed. The direction changing jig 9a is fixed to the floor B, and the direction changing jig 9b is
Is fixed. The fixing jig 11 is fixed to the floor B. C
One end of the FRP 7 is fixed to the fixing portion 5 of the tension base 3, bent by the direction changing jigs 9 a and 9 b, and the other end is connected to the fixing jig 11. Note that a pulley may be used instead of the direction changing jigs 9a and 9b.

The reaction table 13 is fixed to the floor B by bolts 15a and 15b. The reaction force table 13 has a jack 17
a, 17b are provided, and the jacks 17a, 17b pull the connecting rods 12a, 12b to move the tension table 3 to A.
Move to the side. Reference numeral 19 denotes a power supply, which supplies power to the CFRP 7 fixed to the fixing unit 5 and the fixing jig 11. In FIG. 2, the power supply 19 is omitted.

Next, the procedure for producing prestressed concrete will be described. After fixing one end of the CFRP 7 to the fixing portion 5 of the tension base 3 shown in FIG. 1 and FIG.
While bending P7 via the direction changing jigs 9a and 9b,
The other end is connected to the fixing jig 11 and fixed by the fixing jig 11. Next, using the jacks 17a and 17b, the connecting rod 1
The tension table 3 is moved in the direction A in the drawing by pulling 2a and 12b to apply a tensile force to the CFRP7. Then, power is supplied from the power supply 19 to cure the CFRP 7. Note that CFRP
7 is hardened by energizing, and then jacks 17a, 17
The tension may be applied to the CFRP 7 by b.

Next, concrete is poured into the mold 1. After the concrete is solidified, the jacks 17a, 17
Release b and introduce prestress into the concrete.
Then, the CFRP 7 is cut at the side surfaces 21 and 23 of the form 1,
Obtain prestressed concrete.

In this embodiment, the CFR before energization is
P7 is lightweight, easily bent, and easier to handle than PC steel bars and PC steel wires. The cured CFRP 7 is hardly corroded even in a corrosive environment.

FIG. 3 shows a second embodiment of the present invention. In the second embodiment, the tension table 3 is not moved to give a tensile force to the CFRP 7 as shown in FIG.
P itself is pulled.

In FIG. 3, 31 is a mold, 33 is a reaction table fixed to the floor, 35 is a jack, 37 is a CFRP,
9a and 39b are direction changing jigs fixed to the floor, 41 is a fixing jig fixed to the floor, and 43 is a power supply. In addition,
The direction changing jigs 39a and 39b use Teflon or the like to reduce friction. Also, the direction changing jig 39a,
A pulley may be used instead of 39b.

In this embodiment, the CFRP 37 is connected to the jack 3.
5 is connected to the fixing jig 41, the jack 35 is driven to apply a tensile force to the CFRP 37, and the CFR 37
P37 is energized to cure the CFRP37, concrete is poured into the formwork 31 and the concrete is solidified.
The jack 35 is released to introduce prestress.

After the CFRP 37 is energized and cured, the jack 35 may apply a tension to the CFRP 7.

Then, the CFRP 37 is cut on the side surface of the formwork 31 to obtain prestressed concrete.

FIG. 4 shows a third embodiment of the present invention. In the third embodiment, a plurality of molds 51a, 51b.
... 51k ... 51n are provided, and a plurality of prestressed concretes are manufactured at the same time. In FIG. 4, 53 is a direction changing jig fixed to the floor, 55 is a fixing fixed to the floor, and 57 is CFRP. In FIG. 4, a reaction table, a jack, a power supply and the like are omitted. In this embodiment, as in the first and second embodiments, C
After applying a tensile force to the FRP 57, energization is performed and CFRP
After the concrete 57 is hardened, concrete is poured into the molds 51a, 51b... To release the tension of the CFRP 57, and then the CFRP 57 outside the molds 51a, 51b.
A plurality of prestressed concretes are obtained at the same time.

After the CFRP 57 is energized and cured, a jack may be used to apply tension to the CFRP 57.

FIG. 5 illustrates a fourth embodiment.
In this embodiment, a pulley is used as the direction changing jig. In FIG. 5, 61 is a mold, 63 is CF
RP and 65 are movable blocks that can move on the floor surface, 67 is a fixed block fixed to the floor surface, 69a and 69b are fixed portions that fix the CFRP 63 in the movable block 65, 7
1 is a pulley provided on the movable block 65, 73 and 75 are pulleys provided on the fixed block 67, and 77 and 79 are pulleys provided outside. In FIG. 5, illustration of a power supply, a jack, and the like is omitted.

In this embodiment, one end of the CFRP 63 is fixed to the fixing portion 69a, and the CFRP 63 is
Fold at 1, 75 and fix the other end of the CFRP 63 to the fixing part 69
Fix with b. A force is applied in the C direction from outside using a jack or the like to move the entire moving block 65 in the C direction.
A tensile force is applied to FRP63. The CFRP 63 is energized and hardened, and concrete is poured into the formwork 61. After the concrete is solidified, the jack is released. Thereafter, the CFRP 63 outside the formwork 61 is cut to obtain prestressed concrete.

FIG. 6 illustrates a fifth embodiment.
In this embodiment, a pulley is used as a direction changing jig. FIG.
81 is a mold, 83 is CFRP, 85 is a fixed block fixed to the floor, 85 is a fixed portion, 89 is a pulley provided on the fixed block 85, 91 is a fixed block fixed to the floor, 93, Reference numeral 95 denotes a pulley provided on the fixed block 91, and reference numerals 97 and 99 denote pulleys provided outside. Also in FIG. 6, a jack, a power supply and the like are not shown.

One end of the CFRP 83 is fixed to the fixing portion 87 of the fixing block 85, and the other end of the CFRP 83 is connected to the pulley 97 while being bent by the pulleys 93, 89, 95. By applying a force in the D direction from the outside with a jack or the like, C
Pull FRP83. After that, energize the CFRP83
Is hardened, concrete is poured into the formwork 81, and after the concrete is solidified, the force of the jack is released to introduce prestress. And CFRP83 outside the formwork 81
And get prestressed concrete

[0024]

As described above in detail, according to the present invention, it is possible to provide a prestressed concrete which is hardly corroded even in a corrosive environment and can easily arrange tendons at the time of manufacturing, and a method of manufacturing the same. .

[Brief description of the drawings]

FIG. 1 is a plan view of an apparatus for producing prestressed concrete according to a first embodiment of the present invention.

FIG. 2 is a front view of the apparatus for producing prestressed concrete shown in FIG.

FIG. 3 is a plan view of an apparatus for producing prestressed concrete according to a second embodiment.

FIG. 4 is a schematic explanatory view of a third embodiment.

FIG. 5 is a schematic explanatory view of a fourth embodiment.

FIG. 6 is a schematic explanatory view of a fifth embodiment.

[Explanation of symbols]

1, 31, 51k, 61, 81 ... formwork 3 ... tension table 7, 37, 57, 63, 83 ... CFRP 9a, 9b, 39a, 39b, 53 ... direction changing jigs 11, 41, 55 ...... Fixing jigs 13, 33 ... Reaction table 17a, 17b, 35 ... Jack 19, 43 ... Power supply 71, 73, 75, 77, 79, 89, 93, 95, 9
7, 99 ... pulley

Claims (3)

(57) [Claims] 1. a step of bending a carbon fiber reinforced plastic outside a mold while passing it through the mold a plurality of times; a step of pulling the carbon fiber reinforced plastic from both sides outside the mold; A prestressed step comprising: energizing and curing a plastic to cast concrete; casting concrete into the formwork; and cutting the carbon fiber reinforced plastic outside the formwork after the concrete has solidified. Concrete manufacturing method. 2. The method for producing prestressed concrete according to claim 1, wherein the carbon fiber reinforced plastic is turned back outside the form using a pulley. 3. Prestressed concrete produced by the method for producing prestressed concrete according to claim 1.