JPH0458868B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a treatment method that completely prevents defects in the pour joints of concrete structures that require watertightness and airtightness.

[Conventional technology]

As concrete structures become larger and more diverse,
Various construction methods have been studied and adopted. For example, when it comes to pouring concrete, the construction method is determined by taking into consideration the site conditions, scale, capacity of construction machinery, economic efficiency, etc. However, for large structures, it is common practice to pour concrete for the entire structure at once. It cannot be poured. Therefore, in this case, it is customary to provide construction joints and perform the construction in parts.

In general structures, unless there are special requirements, if joints are constructed using conventional methods and with sufficient care, they will not have a major impact on the serviceability and safety of the structure. However, structures that require special functions (watertightness, airtightness, etc.) depending on their use,
For example, various tanks, marine structures, etc. are required to be watertight, including durability, and various pressure vessels, nuclear power containment vessels, etc. are required to be highly airtight.

Conventionally, methods known to ensure watertightness and airtightness at the joints of concrete structures that require watertightness and airtightness include embedding waterstop plates in concrete and intervening adhesives. On the contrary, defects such as new cracks will occur at the joint surface between the embedded material or adhesive and the concrete, so it cannot be used in structures that require high reliability.

[Problem that the invention seeks to solve]

When looking at general structures, focusing on construction joints such as pour joints in concrete structures, there is no particular problem unless there is a special environment.

However, it will be a problem if the durability and functionality are affected due to the poor quality of the construction, or the importance or special nature of the structure. This is because, depending on the conditions, it exhibits the same behavior as a crack.

From this perspective, we will establish a treatment technology that can be applied to general structures of high importance to prevent defects in construction joints, with an emphasis on functionality, even if watertightness or airtightness is not particularly required. After conducting repeated research on this issue, we developed a method that allows the construction joints in concrete walls to perform functionally at least as well as those that are cast in one piece, and established a method for treating the joints.

An object of the present invention is to provide a method for treating concrete pour joints that satisfies the above-mentioned problems.

[Means for solving problems]

The characteristic technical means of the present invention are as follows.

(1) Install pipes for joint treatment of concrete pouring joints and perform concrete pouring. The tube body for this seam treatment has a large number of fine through holes of 200 μm or less in the tube wall, so that cement milk etc. do not enter the tube from the outer periphery, and from the inside it is filled with reactive filling as described below. Use materials that allow the material to leach out.

(2) After the concrete hardens, a reactive filler is press-fitted into the tube.

The reactive filler to be press-fitted is a highly permeable filler that leaches through pores of 200 μm or less and has a pot life of 1 hour or more, and this filler is sometimes integrated with the concrete. In some cases, materials that chemically bond with concrete are used.

If high-pressure injection is required during injection and there is a risk that the pressure may have an adverse effect on the joint, prestress is applied using prestressing steel in the direction in which the joint will be crimped.

[Effect]

In constructing a concrete pouring joint, the present inventors installed a pipe body having a large number of fine through holes in the pipe wall over the concrete pouring joint after concrete was placed in the lower lift, and After the concrete has hardened, a highly permeable reactive filler is press-fitted into the tube, allowing it to seep into the joint through the holes, and the filler is integrally bonded to the concrete at the joint. As a result of various studies on the appropriate size of through holes, it has been found that cement milk and paste in poured concrete do not exist alone, but are completely mixed with a large amount of fine and coarse aggregate. Since it is in a kneaded state,
If the size of the hole is 200 μm or less, cement milk and paste in the concrete will not separate from the concrete and pass through the hole under the pressure of the weight of the poured concrete.
The present invention was completed based on the finding that a highly permeable reactive filler can be press-fitted into a tubular body, pass through a through hole, and be exuded into a seam.

Since the method for treating concrete pour joints of the present invention is configured as described above, the filler is injected into the voids of the pour joints so as to fill the spaces between the pour joints within the working life of the filler, and The use of chemically reactive or bonding materials on the inner surfaces ensures complete integration with the concrete and the complete absence of defects in the pour joints.

〔Example〕

FIG. 1 shows a partial perspective view of a watertight box concrete structure 1 to which the present invention is applied. This box-shaped concrete structure 1 is poured with two lifts of concrete, a lower lift 3 and an upper lift 4, via a pour joint 2. After installing the lower lift 3, a pipe body 5 is placed on top of the pouring seam 2 for seam treatment.
was installed.

The tubular body 5 was made of a perforated plastic pipe or a steel spiral sheath wrapped around a nonwoven fabric. This nonwoven fabric has an opening of 200 μm or less,
A material was selected that allows the reactive filler to pass through, but does not allow cement milk or paste to penetrate into the tube body 5. This pipe body 5 is arranged on the joint surface along the longitudinal direction of the joint seam 2, and an injection port 6 is provided in this pipe body 5, and an appropriate number of pipes are placed at appropriate intervals from the injection port 6. A confirmation hole 8 was provided, and this confirmation hole 8 was opened on the outer surface of the concrete.

After the lower concrete 3 had almost solidified, the concrete 4 for the upper lift was poured.

After the pouring of the upper lift 4 was completed and the concrete had hardened, a cement-based reactive filler was press-fitted from the injection port 6. When the reactive filler began to overflow from the adjacent confirmation hole 8, this confirmation hole 8 was closed, injection was continued, and the adjacent confirmation holes 8 were sequentially closed to increase the injection pressure, and finally all were closed. .

The reactive filler used here reacts with the alkali in the concrete to form silicate, completely eliminating the gap between the pour joints. An organic substance may be press-fitted as a filler and bonded by chemical reaction.

After construction, a detailed inspection using vacuum check and foam check methods revealed no defects that would impair watertightness or airtightness from the seams. In addition, when press-fitting the reactive filler, if particularly high pressure is required, as shown in Figure 2,
Arrange the PC steel material 7 in the direction of crimping the seam 2,
It is better to introduce the required prestress.

〔Effect of the invention〕

According to the method for treating concrete pour joints of the present invention, it is possible to manufacture highly reliable watertight and airtight concrete structures that reliably prevent defects that impair watertightness and airtightness in the pour joints. It has become possible to manufacture marine structures, pressure vessels, concrete pits for low-level radioactive waste, etc. with high reliability.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of a structure illustrating an embodiment of the present invention, and FIG. 2 is a sectional view of concrete using prestressed steel. 1... Concrete structure, 2... Concrete joint, 5
... Pipe body, 6 ... Inlet, 7 ... PC steel material, 8 ...
...Confirmation hole.

Claims (1)

[Claims] 1. When constructing concrete pouring joints, after pouring concrete in the lower lift, a pipe body with a large number of fine through holes of 200 μm or less in the pipe wall is placed over the concrete pouring joint, and concrete is placed in the upper lift. After the concrete has hardened, a highly permeable reactive filler is press-fitted into the pipe body and leached into the pour joint through the through holes, and the filler is integrally bonded to the concrete at the pour joint. A method for treating concrete pour joints.