JP2557136B2 - How to repair concrete structures after a fire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a concrete structure provided with a reinforcing iron plate that surrounds the outer peripheral side of a concrete skeleton such as a pillar or a beam and restrains the same after a fire. Regarding repair methods.

<< Prior Art >> In recent years, as shown in FIG. 2, in order to meet the demand for higher yield strength associated with higher and larger concrete structures, as shown in FIG. 2, pillars 2 (or beams, etc.) of the concrete structure.
There is a known technique in which a cylindrical reinforcing iron plate 6 is provided which is tightly adhered to the outer peripheral side of the concrete skeleton 4 and surrounds and restrains the concrete skeleton (Japanese Utility Model Publication No. 2-51618, etc.).

<< Problems to be Solved by the Invention >> However, as described above, in the concrete structure in which the outer peripheral side of the concrete skeleton 4 of the pillar 2 (or beam etc.) is cylindrically surrounded by the reinforcing iron plate 6 to be restrained. If there is a fire, as shown in Fig. 3,
The reinforcing iron plate 6 is thermally deformed to form a gap 6 between the reinforcing iron plate 6 and the concrete skeleton 4 such as the pillar 2, and the reinforcing iron plate 6 is annealed to lower its strength. As a result, there is a problem that after that, the concrete skeleton 4 cannot be sufficiently restrained by the iron plate 6 from the outer peripheral side thereof, and the proof stress of the column 2 and the like is reduced.

The present invention has been made in view of the above circumstances, and its purpose is to post a fire in a concrete structure provided with a reinforcing iron plate surrounding and restraining the outer peripheral side of a concrete frame such as a pillar or a beam. To provide a repair method.

<< Means for Solving the Problem >> The present invention, when a concrete structure provided with a reinforcing iron plate that surrounds and restrains the outer peripheral side of a concrete frame such as a pillar or a beam is provided with a fire, repairs it. When doing
A step of injecting a filler such as mortar into the gap created between the iron plate thermally deformed by the fire and the concrete skeleton, and surrounding it on the outer peripheral side of the thermally deformed iron plate to newly add a cylindrical reinforcement A step of providing an iron plate and a step of injecting a filler such as mortar into a gap defined between the new reinforcing iron plate and the thermally deformed reinforcing iron plate are performed.

<< Working >> According to the method for repairing a concrete structure after a fire according to the present invention having the above-described configuration, a gap generated between the iron plate thermally deformed by the fire and the concrete frame of the pillar or the beam, and the thermal deformation Since the gap defined between the iron plate and the reinforcing iron plate newly provided by surrounding the outer peripheral side of the iron plate in a tubular shape is filled with a filler such as mortar for repair, The newly provided reinforcing iron plate can effectively restrain the outer peripheral side of the concrete skeleton such as a pillar or a beam, so that the proof stress of the pillar or the beam can be maintained at a desired value or more. In addition, since the heat-deformed iron plate is buried inside without being removed, the work efficiency of repair work is good.

Example An example of a method for repairing a concrete structure after a fire according to the present invention will be described in detail below with reference to the accompanying drawings.

As described in the prior art (see FIGS. 2 and 3), the reinforcing iron plate 6 is provided so as to closely adhere to the outer peripheral side of the concrete skeleton 4 such as the pillar 2 and to enclose and constrain it in a tubular shape. When the concrete structure suffers a fire, the iron plate 6 is thermally deformed and separated from the concrete skeleton 4, and a gap 8 is formed between them.

When repairing a concrete structure that has suffered a fire as described above, in the present invention, first, as shown in FIG. 1 (I), a gap 8 formed between the heat-deformed iron plate 6 and the concrete skeleton 4 is formed. Then, a step of filling a filler 10 such as mortar is performed.

Next, as shown in FIG. 1 (II), the heat-deformed iron plate 6
A step of newly surrounding the outer peripheral side of this with a tubular shape and newly providing a reinforcing iron plate 12 is performed. In the illustrated embodiment, four new flat iron plates 12 are butt-welded to each other at their right and left end portions so as to surround the outer peripheral side of the heat-deformed iron plate 6. Is formed in a rectangular tubular shape, and a gap 14 is defined between the new reinforcing iron plate 12 and the thermally deformed iron plate 6. Further, at this time, the newly provided reinforcing iron plate 12 may be directly welded to the thermally deformed iron plate 6 at the most bulged portion below it, or may be tapped and screwed to be joined. You may do it. The new reinforcing iron plate 12 does not necessarily have to be joined to the thermally deformed iron plate 6. That is,
It is sufficient to arrange the new reinforcing iron plate 12 so that the outer peripheral side of the heat-deformed iron plate 6 is simply surrounded by a cylinder, and the new reinforcing iron plate 12 and the heat-deformed iron plate 6 are completely mutually excluded. It may be in a non-contact state.

After that, the outer peripheral side of the heat-deformed iron plate 6 is provided with a new reinforcing iron plate.
If it is surrounded by 12 in a tubular shape, as shown in Fig. 1 (III), a gap 14 defined between the new reinforcing iron plate 12 and the thermally deformed iron plate 6 is also filled with mortar or the like. A step of filling the filler 16 is performed.

That is, according to the method for repairing a concrete structure after a fire as described above, the gap 8 generated between the concrete skeleton 4 such as the pillar 2 and the iron plate 6 that is thermally deformed by the fire, and the thermal deformation The filler 10 and 16 such as mortar are filled and repaired between the iron plate 6 and the reinforcing iron plate 12 newly provided by surrounding the outer peripheral side of the iron plate 6 in a cylindrical shape. So, the newly installed reinforcing iron plate 12
Thus, the outer peripheral side of the concrete skeleton such as the pillar 2 can be effectively restrained, and thus the proof stress of the pillar 2 or the like can be maintained at a desired value or more. Further, since the thermally deformed iron plate 6 is buried inside without being removed, its work efficiency is good.

Although not shown in the drawing, a newly provided reinforcing iron plate 12
May be formed by joining four flat plates into a rectangular tubular shape by welding them to each other through L-shaped channels at their respective side end portions, or bending them in a U-shaped cross section. Done 2
It is also possible to use a sheet of reinforcing iron plate and weld both ends thereof to each other through an added iron plate to form a rectangular tubular shape.

Moreover, although the column 2 having a rectangular cross-section is illustrated in the illustrated embodiment, the present invention may be applied to a column having a circular cross-section and the like, and is not limited to the column and may be applied to a beam. It is a theory.

<Effect> As described in detail in the above examples, according to the method for repairing a concrete structure according to the present invention after a fire, reinforcement for flexibly restraining the outer peripheral side of a concrete skeleton such as a pillar or a beam. When a concrete structure provided with a steel plate for use in a fire suffers a fire, the gap between the iron plate thermally deformed by the fire and the pillar or the concrete frame, and the heat deformed iron plate when repairing the fire And the outer peripheral side of this iron plate is surrounded by a cylinder, and a filling agent such as mortar is filled in each of the gaps defined between the reinforcing iron plate and the newly provided reinforcing iron plate. The reinforcing iron plate can effectively restrain the outer peripheral side of the concrete frame such as a pillar or a beam, so that the proof stress of the pillar or the beam can be maintained at a desired value or more. In addition, since the heat-deformed iron plate is buried inside without being removed, the work efficiency of repair work is good.

[Brief description of drawings]

FIG. 1 shows an embodiment in which the repairing method according to the present invention is applied to a column, and FIG. 1 (I) fills a gap formed between a heat-deformed iron plate and a concrete frame with a filler. Figure (II) is a cross-sectional view showing the process of providing a new tubular reinforcing iron plate on the outer peripheral side of the heat-deformed iron plate. FIG. 2 is a cross-sectional view showing a step of filling a filler between the iron plate and the heat-deformed iron plate, and FIG. 2 shows a concrete structure which is the object of the present invention. The cross-sectional view of a known column provided with a reinforcing iron plate for
It is a cross-sectional view showing a state after the pillar shown in the figure suffers a fire. 2 …… Pillar 4 …… Concrete skeleton 6 …… Reinforcing iron plate 8 …… Gap between heat-deformed iron plate and concrete skeleton 10 …… Filler 12 …… New reinforcing iron plate 14 …… New reinforcement Gap defined between the iron plate and the heat-deformed iron plate 16 ... Filler

Front page continued (72) Inventor Kenzo Yoshioka 4-640 Shimoseido, Kiyose-shi, Tokyo Inside Obayashi Technical Research Institute Co., Ltd. In-house (56) Bibliography Actual Kaihei 2-51618 (JP, U)

Claims (1)

(57) [Claims] 1. A method for repairing a concrete structure provided with a reinforcing iron plate for surrounding and restraining an outer peripheral side of a concrete structure such as a pillar or a beam after a fire, wherein the iron plate and the concrete structure thermally deformed by the fire. The step of injecting the filler into the gap created between the two, the step of surrounding the heat-deformed iron plate and providing a new cylindrical reinforcing iron plate, and the new reinforcing iron plate and heat A method of repairing a concrete structure after a fire, comprising: injecting a filler into a gap defined between the deformed reinforcing iron plate and the deformed iron plate.