JPH04149351A - Construction method of repairing concrete structure - Google Patents

Abstract

PURPOSE:To make it easy to repair a concrete structure by sticking to a deteriorated concrete wall surface a fiber reinforced plastic plate so formed as to have an irregular surface, and injecting an inorganic material between the wall surface and the plastic plate so as to integrate the wall surface and the plastic plate together. CONSTITUTION:An inorganic material is injected between a surface to be repaired and a fiber plastic plate so that the surface to be repaired and the fiber plastic plate are integrated together, i.e., fiber reinforced plastic is formed from unsaturated polyester resin into a plate by pulling molding method with glass fiber serving as reinforcing material. Quartz sand No.3 is stuck to one side of the plate by means of epoxy resin adhesion so that the surface of the plate is irregular. The irregular surface is joined to the surface to be repaired normal Portland cement, river sand and concrete having a predetermined amount of river sand mixed therein are placed between the irregular surface and the surface to be repaired and are cured for about twenty-eight days and both of the surfaces are integrated with the concrete. Repairing work can thus be carried out in a short construction period without requiring special techniques for construction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for repairing concrete structures using fiber-reinforced plastic plates that have undergone a specific treatment.

[Prior art]

Conventional repair methods for deterioration and damage to concrete structures include the following: 8) Injecting epoxy resin into the deteriorated parts and integrating them, drilling holes in the deteriorated concrete surface and applying epoxy resin After injecting iron rods or pipes, the healthy concrete inside and the deteriorated surface layer are integrated by the anchoring effect. Thereafter, a polymer dispersion such as styrene-butadiene rubber latex, ethylene vinyl acetate emulsion, or polyacrylic acid ester emulsion was mixed. There is a method of repairing with polymer cement mortar, which has excellent adhesion, waterproofness, elongation ability, and resistance to chloride ion penetration and neutralization, and a method of covering the deteriorated part with shotcrete, etc. without scraping it. . In addition, in the case of buildings, in most cases, after repairing using these methods, various types of paints are applied. On the other hand, in order to mainly prevent moisture penetration, which is one of the causes of early deterioration of concrete structures, waterproofing work is also carried out by repairing deteriorated parts and then pasting fiber-reinforced plastic plates with adhesive. There is.

However, despite their excellent physical and chemical properties, fiber-reinforced plastic products manufactured by the conventional pultrusion method are currently only used as materials for the agricultural and fisheries industries. ing. The reasons why fiber-reinforced plastics are not used in a wide range of fields are that the pultrusion method requires a mold during molding, which limits the shape of the product, and that it cannot be welded like metal. , there are few reliable bonding methods.

In general, concrete, mortar, grout, etc. that use various types of cement as binding materials exhibit high alkalinity after hardening.Therefore, fiber-reinforced plastic plates and concrete and mortar.

When considering adhesion of grout, etc., the surface of the fiber-reinforced plastic plate that comes into contact with them is required to have excellent alkali resistance.

The main reinforcing materials for fiber-reinforced plastics include glass fiber, carbon fiber, and aramid fiber, but glass fiber is most often used due to its balance between performance and economy.

Generally, glass fibers have poor alkali resistance, and their reinforcing effect is significantly reduced in the presence of alkali. Matrix resins include unsaturated polyester resins, vinyl ester resins, epoxy resins, phenol resins, polyamide resins, etc. Among them, unsaturated polyester resins are the most common, and the amount used and It covers many fields and occupies a large share.

However, unsaturated polyester resins, except for bis-based ones, have poor alkali resistance.

Therefore, in order to integrate with concrete, mortar, grout, etc., it is necessary to prevent the fiber-reinforced plastic board from being affected by those alkalis.

〔the purpose〕

An object of the present invention is to provide a new method for repairing deteriorated concrete structures using fiber-reinforced plastic plates, which have not been previously used in this field.

(iIl) The present invention integrates an inorganic material between a deteriorated concrete structure and a fiber-reinforced plastic plate whose bonding surface is uneven and whose bonding surface is at least alkali-resistant. This paper relates to a method for repairing concrete structures, which is characterized by

The inorganic material used here fills the gap between the concrete surface and the fiber-reinforced plastic board after the deteriorated parts have been removed. Further, this inorganic material needs to sufficiently adhere to the concrete surface and the uneven surface of the fiber-reinforced plastic board. Inorganic materials used here include concrete, mortar, grout, etc., and binding materials include various types of cement,
There are water glasses etc. In addition, if necessary, these inorganic materials may be mixed with various admixture materials such as a high performance water reducing agent, an AE agent, an AE water reducing agent, a fluidizing agent, a shrinkage reducing agent, a polymer dispersion, a silica neem, and a fly ash. I can do it.

In order to make the adhesive surface alkali resistant, an alkali resistant coating may be provided on the adhesive surface side of the plastic plate, but the resin used itself may be alkali resistant.

The adhesive surface is made uneven by adhering it to the plastic plate using an alkali-resistant adhesive so that one particulate material partially protrudes.

Granular materials include various natural aggregates or artificial aggregates, flaky iron pieces, ceramic pieces, etc. Alkali-resistant adhesives include epoxy resin adhesives, vinyl acetate resin adhesives, chloroprene rubber adhesives, and nitrile. Examples include rubber adhesives and acrylic resin adhesives.

More specifically, the present invention includes: (1) Scraping off the deteriorated part, applying repair mortar or putty to the part, and pasting a fiber-reinforced plastic plate with granules attached thereon to integrate it.

(2) After scraping off the deteriorated area, cover the area with a fiber-reinforced grating board with granules attached and temporarily fix it, inject repair mortar or grout into the area where the scraping force is applied, and repair it. Integrates fiber-reinforced plastic plates.

It is something.

Since fiber-reinforced plastic plates are lightweight, repair work at relatively high places can be carried out safely and easily on-site, and there is no need to remove the fiber-reinforced plastic plates after injecting mortar or grout, significantly shortening the construction period. can be achieved. Furthermore, by protecting a concrete structure with a fiber-reinforced plastic plate that has excellent weather resistance, corrosion resistance, chemical resistance, and waterproofness, the durability of the structure can be improved. In particular, it is possible to prevent penetration of moisture, oxygen, and chloride ions from the outside, which are necessary for corrosion of reinforcing bars, which causes early deterioration of reinforced concrete structures. Furthermore, by using the construction method of the present invention, the durability of marine structures and concrete structures near the coast can be significantly improved. Therefore, it is possible to expand the use of fiber-reinforced plastic molded products, which have hitherto had a limited range of use, in the civil engineering and construction fields.

〔Example〕

Fiber-reinforced plastic plate made by pultrusion using glass fiber as the reinforcing material and unsaturated polyester resin as the matrix material Dimensions: 10 x O, 4 x 4
A 0■ board was cut out.

No. 3 silica sand was attached to one side of the cut fiber-reinforced plastic plate using an epoxy resin adhesive with excellent alkali resistance. Next, the side of the fiber-reinforced plastic board to which the silica sand was attached was coated with ordinary Portland cement and river gravel (
5 to 20 mm) and river sand (5 fields or less), pour concrete with the mix shown in Table 1. 1 dimension: 10 x 10 x 4
It was molded to a size of 0. 28 days humid air (20℃, 80%R, l(
,) After curing, a steel attachment with a bonding area of 4×4aa was attached to the fiber-reinforced plastic plate integrated with the concrete. After that, JIS A6915 (
The tensile bond strength of the fiber-reinforced plastic plate to concrete was tested using a Kenken-type tensile bond strength tester (according to the thickness of the final coating material). As a result, the tensile adhesive strength of the fiber-reinforced plastic plate was 36 kgf/c.
i, and it became clear that the failure occurred in the underlying concrete.From this, the fiber-reinforced plastic board
It can be seen that it is not affected by the alkali of concrete at all, and that it is completely integrated with the concrete.

Table 1 Concrete Mixture [Effects] As explained above, the repair method for concrete structures using fiber-reinforced plastic according to the present invention has extremely good workability, shortens the construction period, and does not require very special construction techniques. do not need. Further, after integration, dirt on the surface of the fiber-reinforced plastic plate can be easily removed by washing with water. Since the surface is made of fiber-reinforced plastic, it has excellent cosmetic properties, but it can also be coated with various paints if necessary. Furthermore, since no organic adhesive is used at the work site, the solvent does not volatilize, and no heating work is performed, so the work environment can always be maintained in a good condition. Therefore, subway tunnels, undersea tunnels,
This construction method is ideal for work in closed locations such as mountain tunnels, building basements, and warehouses.

This construction method is extremely effective in repair work or new construction of buildings, bridges, marine structures, and coastal structures such as breakwaters and piers.

Claims (1)

[Claims] 1. It is characterized by injecting an inorganic material between a deteriorated concrete structure and a fiber-reinforced plastic plate whose bonding surface is uneven and whose bonding surface is at least alkali-resistant to integrate the two. Repair method for concrete structures.