JPH01163365A - Method of treatment construction of concrete construction joint - Google Patents

Abstract

PURPOSE: To improve reliability by placing a lower lift, arranging a tube body having fine holes on a placing joint, placing an upper lift, pressing a filler into the tube body after hardening, and integrally connecting the filler to place joint concrete. CONSTITUTION: A lower lift 3 is placed, then a tube body 5 wound with a nonwoven fabric around a porous plastic pipe is arranged on a placing joint 2. The nonwoven fabric is selected having pores below 200 μm is water- permeable but cement milk-nonpermeable, and the tube body 5 is provided with an injection port 6 and a proper number of confirming holes 8. After the lower lift 3 is nearly fixed, a lift 4 is placed. After concrete is hardened, a cement reactive filler is pressed-in from the injection port 6, and the filler is reacted with alkali in the concrete to form silicate. Thus gaps of the placing joint 2 are completely removed, and reliability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a treatment method that completely prevents defects in pour joints of concrete structures that require watertightness and airtightness.

[Prior Art] As concrete structures become larger and more diverse, various construction methods have been studied and adopted in accordance with the increasing size and diversification of concrete structures. For example, when concrete is poured, site conditions,
The construction method is decided based on the scale, capacity of construction machinery, economic efficiency, etc. However, for large structures, it is generally not possible to pour concrete for the entire structure at once. Therefore, in this case, it is customary to provide construction joints and perform the construction in parts.

-M In structures, unless there are special requirements, if the 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, such as various tanks and marine structures, require watertightness including durability, and various pressure vessels, etc. Nuclear containment vessels require high airtightness.

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, it causes defects such as new gaps 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 to be solved by the invention 1 When looking at general structures with attention to construction joints such as pouring joints in concrete structures, there are no particular problems unless there are special circumstances.

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 at concrete pour joints and perform concrete pour joints. The pipe body for this seam treatment has a large number of fine through holes of 200 μm or less in the pipe wall, so that cement milk etc. do not enter the pipe 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 one with high permeability.
A filler that leaches through pores of 0 μm or less and has a pot life of 1 hour or more, which is integrated with the concrete when it is injected, and which chemically bonds with the concrete when it is injected, is used. ).

If pressurized injection is required at the time of injection, and if the pressure may have an adverse effect on the joint, prestress is applied using a prestressing steel material in the direction of crimping the pour joint.

[Function] 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 gaps between the pour joints within the usable life of the filler, and Moreover, since it uses a material that chemically reacts or bonds with the surfaces within the gap, it is completely integrated with the concrete, ensuring that defects in the pour joints are completely eliminated.

Embodiment 3 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 the lower lift 3 was installed, a pipe body 5 for seam treatment was placed above the installed joint 2.

The tubular body 5 was a perforated plastic pipe or a steel spiral sheath wrapped with a nonwoven fabric. This nonwoven fabric was selected to have an opening of 200 μm or less and to allow water to pass through, but not to allow cement milk or paste to penetrate into the tube body 5. This pipe body 5 is disposed 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. Confirmation hole 8
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 upper lift 4 was finished placing 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 reacts with the alkali in the concrete to form silicate, completely eliminating the gaps between the joints. An organic solvent may be injected as a filler and bonded by chemical reaction.

After construction, a detailed inspection was conducted using vacuum check and foam check methods, and no defects were found that would impair watertightness or airtightness from the seams. In addition, when press-fitting the reactive filler, if pressurization is particularly required, as shown in Fig. 2, the PC steel material 7 is arranged in the direction of crimping the seam 2, and the required prestress is applied. It is a good idea to introduce.

[Effects of the Invention] According to the method for treating concrete pouring 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 pouring joints. For example, offshore structures such as caissons, pressure vessels,
It has become possible to manufacture concrete bits for low-level radioactive waste with high reliability.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view of a structure explaining the present invention in detail;
FIG. 2 is a cross-sectional view of concrete using PC steel. 1... Concrete structure 2... Concrete joint 5 - Pipe body 6... Inlet a... PC steel material 8... Confirmation hole

Claims (1)

[Claims] 1. When constructing a concrete pouring joint, after concrete is poured by the lower lift, a pipe body having a large number of fine through holes of 200 μm or less in the pipe wall is placed above the concrete pouring joint. Then, the concrete of the upper lift is poured, and after the concrete hardens, a highly permeable reactive filler is press-fitted into the pipe body and leached into the pouring joint through the through hole, and the filler is poured into the pouring joint. A method for treating concrete pour joints that is characterized by integrally bonding them with concrete.