JPH0652010B2 - Repair method for reinforced concrete - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for repairing a concrete structure made of deteriorated reinforced concrete.

(Prior art and its problems) In reinforced concrete structures, carbonation in the air, rainwater, etc., cause the carbonization of the concrete, and cracks due to contraction of concrete cause moisture to enter the inside of the skeleton. Rust occurs. When the reinforcing bar rusts, its volume expansion promotes the generation of cracks in the body. By repeating this, deterioration of the concrete skeleton is gradually promoted, and the durability is significantly impaired.

Japanese Patent Publication No. 57-11988 discloses a technique for recovering the alkalinity of such a concrete skeleton.

This method applies a solution of a water-soluble silicate compound to the surface of deteriorated concrete to impregnate it into the skeleton, reinforces the weakened concrete layer, and restores the alkalinity of the neutralized part to rebar. It was intended to have rust prevention.

However, in this method, since the solution of the water-soluble silicate compound is only applied from the surface side of the concrete layer, it is possible to give the alkaline restoration effect only to the surface side of the skeleton, and already the rust Can not be placed in a suitable alkaline atmosphere, or only one side of the reinforcing bar is placed in an alkaline atmosphere,
There is an inconvenience that sufficient reinforcing effect and rust preventive effect cannot be obtained.

(Technical problem) An object of the present invention is to prevent corrosion of the entire periphery of a reinforcing bar in a method of repairing a concrete structure made of deteriorated reinforced concrete.

(Technical Means) Technical means for solving this technical problem are (a)
After shaving the deteriorated part of the body to expose the reinforcing bar, (b) After making a gap between the reinforcing bar and fixing the injection pipe to the scraping part with an adhesive, (c) Applying rust preventive liquid from the injection pipe into the structure Inject and
(D) After that, the surface layer of the body is shaped.

(Operation of technical means) Since the injection pipe is fixed to the shaving part where the reinforcing bar is exposed by using an adhesive or the like, injection can be started in a short time.

Since the injection pipe has a gap between it and the rebar, the rust preventive liquid injected from the injection pipe into the body smoothly enters through the pipe hole into the slight gap formed at the boundary between the rebar and the body. However, the outside concrete is impregnated while covering the surface of the rusted reinforcing bar.

As the rust preventive agent, inorganic compound salts or amine organic acid salts obtained by combining an inorganic acid such as nitrous acid, sulfonic acid, phosphoric acid and an alkali metal or an alkaline earth metal are used, sodium hydroxide, hydroxide It is possible to use an aqueous alkaline solution such as calcium, sodium silicate, or lithium silicate, which serves as an auxiliary agent for forming an immobile oxide film on the reinforcing bars.

In this injection method, the rust-preventive liquid is impregnated into the skeleton and rust centering on the rebar, so if the surface layer of the skeleton is shaped and the exposed rebar is shielded from the outside air and placed in a buried state, the rebar will be completely removed. The circumference will be covered with anticorrosive liquid.

This surface layer is shaped by forming a coating layer by casting, coating or injecting cement paste, resin concrete, resin, etc. on the scraped or scraped part of the body, or forming a protective layer on the entire surface of the body. It will be done.

When a crack or the like is generated in the concrete body, an adhesive or the like is injected into the crack to prevent rainwater from entering and maintain the rust preventive effect in the concrete body for a long time.

(Effects of the present invention) As a result of being able to prevent rust around the entire reinforcing bar, the entire reinforcing bar can be placed in a rustproof state for a long period of time, and there is an advantage that the progress of rust in the entire reinforcing bar and the expansion of the concrete layer caused thereby can be prevented. Therefore, it is possible to prevent the progress of cracking and peeling off of the concrete layer thereafter.

(Examples) Next, specific examples of the above technical means will be described with reference to the drawings.

FIG. 1 shows a cross section when the concrete wall (1) is shaved to expose the reinforcing bar (2) for repair.

The shavings on the wall (1) were cleaned to remove rust on the rebar (2) ((a)
Then, the tip of the pipe (3) is fixed to the scraped portion with an adhesive (4) in a state where the tip of the pipe (3) is brought close to the reinforcing bar (2) (see (b)).

When the solution of the water-soluble silicate compound was injected from the rear end of the pipe (3) at the stage where the adhesive (4) was hardened, the solution was between the concrete wall (1) and the reinforcing bar (2). enter in.

Next, the pipe (3) was closed to sufficiently impregnate the solution of the water-soluble silicate compound into the rust and concrete, after which the adhesive (4) and the pipe (3) were removed, and the resin concrete was applied to the scraped part. The repair work is completed by placing (5).

FIG. 2 is a front view showing a repairing method when a crack (15) is generated in the concrete wall (11).

A seal is applied along the surface of the crack (15), and the concrete wall (11) on the front side of the reinforcing bar (12) is cut to form a hole (16) <see solid line portion>.

After cleaning the inside of the hole (16), an injection pipe (not shown) is fixed to the opening of the hole (16) and an aqueous sodium hydroxide solution is injected to surround the reinforcing bar (12) and inside the crack (15). , The injection pipe is closed, and the sodium hydroxide aqueous solution is sufficiently impregnated into the rust and the concrete.

Next, a hole (17) <refer to the dotted line part> is formed at an appropriate interval along the crack (15), an injection pipe is fixed to the opening, and the hole (16) is formed by using the injection pipe. Inject concrete into crack (15) from (17) to concrete wall
Reinforce and shape the surface layer of (11). In this case, it is also possible to use only the hole (16) for both purposes without forming the hole (17).

In this example, the hole (17) for injecting the adhesive is formed after the injection of the anticorrosive liquid, but the hole (16) for injecting the anticorrosive liquid is formed at the same time as the antirust liquid. A cap or the like may be appropriately closed during the injection.

[Brief description of drawings]

The drawings are for explaining specific examples of technical means,
FIG. 1 is a sectional view of a concrete wall at a repaired portion, and FIG. 2 is a front view of a concrete wall in another embodiment. (1) (11) concrete wall, (2) (12) rebar, (4) adhesive, (1
5) Crack, (16) (17) hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsutomu Matsuo 2-6, Doshomachi, Higashi-ku, Osaka-shi, Osaka Within Konishi Co., Ltd. No. Sunkit Co., Ltd. (56) Reference JP-A-63-117068 (JP, A)

Claims (3)

[Claims] 1. A method for repairing a structure made of deteriorated reinforced concrete, wherein the deteriorated part of the skeleton is shaved to expose the reinforcing bar, and a gap is provided between the reinforcing bar and the injection pipe to be fixed to the scraped part with an adhesive. A repair method in which a rust preventive liquid is injected into the body from an injection pipe, and then the surface layer of the body is shaped. 2. The repair method according to claim 1, wherein the reinforcing bars are exposed by shaving the concrete skeleton into a hole shape. 3. The repair method according to claim 1, wherein shaping of the surface layer of the skeleton involves injecting an adhesive into cracks generated in the concrete skeleton.