JPS63217068A - Construction method for repairing reinforced concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for repairing reinforced concrete.

[Conventional technology]

The reinforcing bars in reinforced concrete are inhibited from rusting by the alkali in the concrete, which extends the lifespan of reinforced concrete as a structure. However, if cracks occur in the concrete or there is insufficient coverage of the reinforcing bars , rust may occur on reinforcing bars due to the carbonation of concrete.

When the reinforcing steel rusts, the rust expands by about 10 times the volume of the steel, pushing out the concrete (generally called explosion).
Eventually, the concrete will flake off, exposing the rusted reinforcing steel.

Various methods have been tried to repair such areas, but in general, the weak or deteriorated concrete is broken down, the rust on the reinforcing bars is removed, and anti-corrosion treatment is applied before applying mortar. It is being repaired.

[Problem that the invention seeks to solve]

However, although this construction method is good for the parts where the concrete has been removed, the reinforcing bars of the cabinet are definitely rusting, and there is a possibility that an explosion phenomenon will occur again in a few years around the repaired parts. There are many.

In order to prevent this, it would be better to remove more parts, but there is also the problem of strength as a structure, and as a practical matter, the limit is about 1/10 of the surface area.

This invention was made in order to solve such conventional problems, and it is possible to suppress the progress of rust not only in the part where concrete has been removed, but also in the surrounding reinforcing bars, and therefore Another object of the present invention is to provide a method for repairing reinforced concrete that can suppress the progress of rust on reinforcing bars without increasing the number of parts to be removed from the concrete.

[Means for solving problems]

The method for repairing reinforced concrete according to the present invention includes a reinforcing steel tube made of flexible resin with a cut section in the length direction, and a pipe that stands up on the reinforcing steel tube and opens into the interior of the reinforcing steel tube. This is a construction method that uses a repair material injection tool, in which the deteriorated concrete is removed, the reinforcing steel tube of the repair material injection tool is placed over the reinforcing bars, and the pipe is raised outward.
Then, injecting the repair material into the pipe, ``To avoid embedding 111, the concrete part that has been removed is repaired with mortar, and after this hardens, the repair material is press-fitted into the pipe. .

(Function) When the rebar covering tube of the repair material injection tool is placed over the rebar, a gap is created between the two. This gap will remain even after being repaired with mortar. When a repair material such as a rust preventive material or epoxy resin is press-fitted through a pipe into this gap, it passes through the gap and fills the micro cracks in the concrete around the reinforcing bars and the micro voids between the concrete and the concrete that have formed under the horizontal bars. penetrate,
Fill these.

The above-mentioned micro-cracks occur in the concrete around the reinforcing bars due to rusting and expansion of the reinforcing bars, and the above-mentioned micro-voids are caused by settling of aggregate when the concrete hardens, so these cracks and voids are usually , communicated over a wide range. Therefore, the repair material will be filled over a wide area.

As a result, water and air do not enter through the cracks and voids, and the carbonation of the concrete is suppressed over a wide range, and the progress of rust on the reinforcing bars is also suppressed. Furthermore, as described above, since the repair material penetrates into cracks and voids, there is no need to reduce the strength of the reinforced concrete structure by increasing the number of cracked parts of the concrete.

(Example〕 An embodiment of the present invention will be described below with reference to FIG.

In the following two embodiments, as shown in Fig. 2, there is a reinforcing bar covering tube 2 made of flexible resin with a cut portion 1 in the length direction, and a reinforcing bar covering tube 2 that is raised up and one end is opened inside the tube. , a repair material injection tool T consisting of a pipe 3 with a repair material injection port 3a at the other end was used. Note that 2a is a notch provided at both end corners of the cut portion 1 to facilitate fitting of the reinforcing bar attachment tube 2 to the reinforcing bar.

(Example 1) As shown in Figure 1, the deteriorated concrete in the area where the concrete 5 of a reinforced concrete structure exploded and the red and rusted reinforcing bars 4 were exposed was removed to remove the rust from the reinforcing bars 4. Thereafter, a tannin-based rust-preventive paint was applied to the reinforcing bar 4, and the repair material injection tool T was attached thereto. That is, the reinforcing bar covering tube 2 was placed over the reinforcing bars 4 coated with antirust paint, and the pipe 3 was raised outward. Next, the secured concrete portion was repaired with mortar 6 so as not to embed the repair material injection port 3a of the pipe 3.

One week later, a lithium silicate aqueous solution having a rust-preventing effect was injected from pipe 3 at a pressure of I KG/l; M2. Thirty minutes after the injection, the lithium silicate aqueous solution oozed out from the cracks in the concrete 5, which was 1 ml from the injection tube. It was confirmed that the aqueous solution was sufficiently applied to the unrepaired areas where rust would progress in the future.

(Example 2) As shown in Figure 1, the deteriorated concrete 1 in the area where the concrete 4 of the reinforced concrete structure exploded and exposed the red and rusted reinforcing bars 4 was removed and the rust on the reinforcing bars 4 was removed. After dropping the reinforcing bar 4, an epoxy resin-based anticorrosion paint was applied to the reinforcing bar 4, and the repair material injection tool T was attached thereto in the same manner as in Example 1. Next, the removed concrete portion was repaired with mortar 6 so as not to embed the repair material injection port 3a of the pipe 3.

! After a week, from pipe 3 to 1 at a pressure of G/CM'
Injected with ocps low viscosity epoxy resin.

The next day, in order to investigate the state of the epoxy resin injection, the epoxy resin was injected into the gap between the reinforcing bars 4 and the concrete 5 within a range of 50 cm from the pipe 3. Traces of Based on this condition, it was confirmed that it was possible to suppress the progress of rust in the unrepaired areas in the future.

In each of the above embodiments, the case of horizontal stripes has been described, but the same applies to the case of vertical stripes.

〔Effect of the invention〕

As explained above, according to the present invention, a repair material injection tool is attached to the reinforcing bars exposed by removing deteriorated concrete, and then that part is repaired with mortar.
Since the repair material was injected into the entire pipe of Injection A, the repair material penetrated and filled the cracks and voids in the concrete around the area other than the repaired area, suppressing the neutralization of the concrete in this area. , the progress of rust on reinforcing bars is suppressed. Furthermore, as described above, since the repair material permeates, the progress of rust on the reinforcing bars can be suppressed without reducing the strength of the structure by increasing the number of softening parts of the concrete.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a reinforced concrete structure for explaining the present invention in detail, Fig. 2 shows an example of a repair material injection tool used in the embodiment, and Fig. 1(a) is a front view. b) is a side view, and the same figure (c) is a plan view. T -------Repair material injection tool! - Cut section 2 - Reinforcement tube 3 Pipe 3a-1 Repair material injection port Applicant Mitsubishi Yuka Co., Ltd. (3 others) Fig. 1 T wi suma fitting 1 4: Another hot P paste part 2, iron rib break 1 cylinder 3: Pie 1 3a: Repair #ma entering a

Claims (1)

[Claims] This is a construction method that uses a repair material injection tool consisting of a reinforcing steel tube made of flexible resin with a cut section in the length direction, and a pipe that stands up on this reinforcing steel tube and opens into the inside. Then, remove the deteriorated concrete, cover the reinforcing steel with the rebar covering tube of the repair material injection tool, and raise the pipe outward. A reinforced concrete repair method characterized by repairing the removed concrete part with mortar, and then press-fitting repair material through a pipe after this hardens.