JPH0454784B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention applies cement-containing binding materials such as cement paste, mortar, and concrete to parts to be joined such as damaged parts, cracked parts, and joint parts of concrete buildings. This relates to a method of pouring and joining.

[Conventional technology]

Concrete is damaged by poor placement, cracks in the concrete due to corrosion of reinforcing bars, deterioration due to carbonation, impact, abrasion, etc. The degree of damage varies depending on the environment, degree of deterioration, etc., but sometimes the reinforcing bars inside are exposed and corrosion is accelerated significantly. In particular, concrete structures placed in coastal areas can be severely damaged by weather, wave forces, floating objects, etc., and corrosion of reinforcing bars is a particular concern in such environments. In addition, damage in seawater or freshwater can be severe and lead to structural problems, and in such environments and deterioration, reinforcing bars can rapidly corrode and even dissolve.

The conventional method for repairing damaged parts of concrete structures is to remove chips from the surface of the damaged part and clean it, then set a formwork and pour concrete or other cement-containing binding material to form the part to be joined. The method used was to attach it to the damaged part.

In addition to repairing damaged parts, when joining a cement-containing binder to the parts to be joined, such as when joining an existing concrete structure or segment, the formwork is similarly set and the cement-containing binder is The conventional method used was to pour and join the parts to the parts to be joined.

[Problem that the invention seeks to solve]

However, in the conventional method of joining cement-containing binders as described above, since a new uncured cement-containing binder is joined to an already hardened concrete joint, the bondability of the joint surfaces (seam joints) may be affected. There was a problem in that the entire post-molded part would peel off during demolding or due to subsequent impact.

Especially in coastal areas, there is a lot of humidity and deposits,
The bondability of the post-casting portion becomes even worse, and when repair or jointing is performed underwater, not only the bondability deteriorates, but also problems such as strength deterioration due to dilution in water occur. Underwater concrete containing water-soluble polymers with water-retentive properties and admixtures such as high-performance water reducers that improve dispersibility has been put into practical use as concrete that does not separate even under water. It is also possible to pour the concrete into the concrete, but this poses the problem that the bondability with the existing concrete and reinforcing bars cannot be sufficiently improved.

This invention is intended to solve the above-mentioned problems, and aims to propose a method for joining cement-containing binders that has good bondability and strength development at the joint.

[Means for solving problems]

The present invention is a method for joining a cement-containing binding material to a jointed part, characterized by pouring an epoxy resin into the joining part, and then pouring the cement-containing binding material to replace the epoxy resin. This is a method for joining cement-containing binders.

In the present invention, the cement-containing bonding material is a paste-like or mud-like bonding material containing cement, such as cement paste, mortar, or concrete, which hardens and bonds by pouring and curing. In addition to general cement, there are also cements that contain polymeric substances and other admixtures. Therefore, such cement-containing binders include not only general cement paste, mortar, and concrete, but also polymer cement mortar, polymer cement concrete, resin mortar, resin concrete, underwater concrete, and the like.

The parts to be joined with these cement-containing binders include damaged parts and cracked parts of concrete structures, as well as parts that require new joining of cement-containing binders, such as joints of existing concrete or segments. The target material is generally concrete, but other materials such as metal and resin may also be used. In addition, it is particularly effective when the part to be joined is located near the coast or underwater;
It is also applicable to parts to be joined that exist on the ground in general.

In the present invention, before casting the cement-containing binding material for these parts to be joined, epoxy resin is poured into the parts to be joined. Epoxy resins are resins having epoxy groups in their molecules or resins produced by ring-opening polymerization thereof, and are widely used as adhesives for concrete in the fields of civil engineering and construction. The characteristics of epoxy resin are as follows.

Relatively high viscosity.

It is usually several thousand cP, but can be several hundred cP.

Short curing time.

Although the curing time (gelation time) can be controlled by selecting the curing material, the range is small and is approximately 1 to 2 hours.

No by-products are produced during curing, and shrinkage is extremely low.

Excellent adhesion.

Very good water and chemical resistance.

High mechanical strength.

In the present invention, such an epoxy resin is mixed with a curing agent and poured into the parts to be joined, and before the mixture hardens, a cement-containing binding material is cast to replace the previously poured epoxy resin. At this time, since the epoxy resin poured first comes into contact with the parts to be joined first, it adheres to the surface of the parts to be joined, and even after being replaced with the cement-containing binder, there is a boundary between the parts to be joined and the post-cast cement-containing binder. It remains on the surface and hardens, acting as an adhesive.

If the part to be joined is an upwardly facing recess, etc., the epoxy resin and cement-containing binding material may be poured or cast as is without using a formwork, etc.; It is desirable to set the temporary formwork so as to cover the surfaces to be joined, such as the joints. The same applies when the parts to be joined are underwater. When the parts to be joined are located on the coast, there may be deposits on the parts or the parts may be wet, so it is preferable to perform chipping and cleaning in the same way as in the past in order to improve the joining performance. It is preferable to use a mold that has low adhesiveness to epoxy resin.

It is not necessary to completely fill the epoxy resin into the part to be joined or the formwork, but after pouring the epoxy resin to the extent that it partially fills the part and then injecting the cement-containing binding material under the epoxy resin layer, it is possible to fill the part to be joined or the mold. Replacement casting is performed sequentially from the bottom of the frame to the top, and the parts to be joined are covered with epoxy resin.

When a cement-containing bonding material is cured and cured after casting, the epoxy resin cures faster than the cement-containing bonding material, so the post-cast cement-containing bonding material is firmly bonded to the parts to be joined by the epoxy resin. and bondability is good. In addition, if a cement-containing binder is injected under the epoxy thread resin layer to replace it, the surface of the cement-containing binder is covered with the epoxy resin during pouring and curing, so it is not underwater concrete. Even when a normal cement-containing binder is used, there is no separation due to water, and even when pouring is done in water, the strength development is good.

Curing does not require any special operations; it is sufficient to maintain the cast condition as it is. After the cement-containing binding material has hardened, the formwork is removed, but since the epoxy resin has hardened before the cement-containing binding material hardens, the post-molded part will not peel off when the mold is removed.

〔Example〕

Hereinafter, the present invention will be explained with reference to embodiments of the drawings.
FIGS. 1A to 1E are cross-sectional views showing the steps of an embodiment of the present invention. This embodiment shows a case where a damaged part 2 of a concrete structure 1 existing in water is to be repaired.

First, as shown in FIG. 1B from the state shown in FIG. Then, as shown in C, the injection pipe 5 is inserted into the mold 3, and the epoxy resin 6 is poured into a part of the damaged area 2. Next, as shown in FIG.
The process is continued until the cement-containing binding material 7 is almost completely filled in the formwork 3 as shown in FIG. At this time, water 8 inside the formwork 3
The epoxy resin 6 and the epoxy resin 6 sequentially flow out from the openings of the mold 3 by the above operations. After pouring the cement-containing binding material 7, the injection pipe 5 is removed, and if necessary, the formwork 3 is completely closed to cure and harden.

FIGS. 2A to 2C are sectional views showing the steps of another embodiment. This example is for the existing concrete structure 1
The case is shown in which the splicing is performed at the splicing section 9 of. First, as shown in FIG. 2A, a mold 3 is set so as to cover the joining part 9, which is the part to be joined, and epoxy resin 6 is poured into the mold 3 from the injection pipe 5. At this time, the back water 10 flows out over the formwork 3. Next, as shown in B, a cement-containing binding material 7 is injected from the injection pipe 5 onto the underside of the epoxy resin 6 to replace the epoxy resin 6. As this operation continues, the back water 10 flows out over the formwork 3, and then, as shown in C, the epoxy resin 6 flows out over the formwork 3, and the formwork 3 is filled with cement-containing binder. 7, the pouring is completed at that point, the mold is cured, and the mold is removed.

In the above example, the hardened cement-containing binding material 7 and the concrete structure 1 are bonded via the epoxy resin remaining at the interface, so the bonding properties are good, and the cement-containing binding material 7 is used during pouring and curing. Since 7 does not come into contact with water, there is no separation due to water and the strength is high.

The casting method for cracks in concrete structures, segment joints, and other cases can be performed in substantially the same manner as in the above embodiments.

〔Effect of the invention〕

According to the present invention, after pouring the epoxy resin into the parts to be joined, the cement-containing binding material is placed and replaced, so that the following effects can be obtained.

Good bondability and strength development at the joint.

Epoxy resin can efficiently perform bonding and coating with a small amount.

There is no need to perform any special operations to drain the water from the pouring area, and the concrete can be poured as is.

Epoxy resin hardens faster than cement-containing binders, and does not peel off when demolded.

The cement-containing binding material is not limited to underwater concrete, and any other material can be used, depending on the environment.

The joints are made of epoxy resin, so they are watertight and prevent water from entering.

Since it adheres better to the reinforcing bars, there is less corrosion of the reinforcing bars.

[Brief explanation of the drawing]

1A to 1E and 2A to 2C are sectional views showing steps of different embodiments, and the same reference numerals in each figure indicate the same or corresponding parts. 1... Concrete structure, 2... Damaged part, 3
... Formwork, 5 ... Injection pipe, 6 ... Epoxy resin, 7 ... Cement-containing binding material, 9 ... Connection part.

Claims (1)

[Scope of Claims] 1. A method for joining a cement-containing binding material to a part to be joined, which includes pouring an epoxy resin into the part to be joined, and then pouring a cement-containing binding material to replace the epoxy resin. Characteristic bonding method for cement-containing binders. 2. The method for joining a cement-containing binding material according to claim 1, wherein the part to be joined is a damaged part, a cracked part, or a joint part of a concrete building or segment. 3. The method for joining cement-containing binding materials according to claim 1 or 2, wherein the parts to be joined are on the ground or in water. 4. The method for joining a cement-containing binding material according to any one of claims 1 to 3, wherein the part to be joined is covered with a formwork. 5. The method for joining a cement-containing binding material according to any one of claims 1 to 4, wherein the cement-containing binding material is cement paste, mortar, or concrete.