JP2022158838A - Epoxy-based filler and method for repairing concrete structure using the same - Google Patents

Abstract

To provide a two-pack curable epoxy-based filler capable of improving filling in a gap such as a rock pocket.SOLUTION: An epoxy-based filler is a two-pack curable epoxy-based filler to be injected to a gap of a rock pocket of a concrete structure, a gap around a reinforcement or a gap of a placing joint part, and has a pot life at 23°C of less than 15 minutes and an elongation rate after curing of more than 10%.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a two-liquid curing type epoxy-based filler to be injected into gaps around junkers or reinforcing bars of concrete structures, and a method of repairing concrete structures using the same.

Many tunnels were built during the period of rapid economic growth after the war, and the number of tunnels that have deteriorated over the years has continued to increase. In addition, there are tunnels that have deteriorated prematurely over time due to construction defects such as junkers due to the construction circumstances at the time.

For this reason, the importance of tunnel maintenance is increasing, and although many methods for safe and efficient inspection and repair of defective parts have been studied, there are still many problems with inspection accuracy and repair methods.

For example, Patent Document 1 discloses a high-pressure construction method in which a hole is drilled in a crack of a concrete structure or the like, and a nozzle of a high-pressure injection valve is inserted into the hole to repair by injecting epoxy resin. In the container, an elastic body is interposed between the cylinder and the piston, and similarly a hole is drilled in the cracked part of the concrete structure, etc., and the nozzle of the injector is inserted into the hole, and the compressive force of the elastic body causes the epoxy to be injected into the cylinder. A resin injector for use in a method of repairing by injecting resin is disclosed.

Further, Patent Documents 2 and 3 disclose injecting an epoxy resin into cracks of a concrete structure, gaps between junkers, and gaps around reinforcing bars.

JP 2017-031661 A JP 2018-104996 A JP 2015-030987 A

The present inventors found that when the adhesive described in Patent Documents 1 to 3 is injected into the gaps of the junker (bean board), the adhesive fills the gaps between the gravel of the junker once, but is injected during the time until it hardens. We have found problems with insufficient filling in the janka due to dripping or spilling from the side or unexpected voids.

The present invention has been made in view of the above circumstances, and its object is to provide a two-liquid curing type epoxy filler capable of improving filling in gaps such as junkers in junker repair of concrete structures, and the like. To provide a method for repairing a concrete structure using

As a result of extensive studies to solve the above problems, the present inventors have found that if it is a normal construction, there are many restrictions, the pot life is shorter as the construction difficulty increases, and the elongation after curing is within a specific range. It was found that the above problems can be solved by using the two-liquid curing type filler in the above for repairing concrete structures.

That is, the gist of the present invention is as follows.

The epoxy-based filler according to the first invention is a two-liquid curing epoxy-based filler to be injected into gaps in concrete structures, gaps around reinforcing bars, or gaps in joints, wherein epoxy The system filler has a pot life of less than 15 minutes at 23° C. and an elongation after curing of greater than 10%.

As described above, the epoxy-based filler of the present invention has a low viscosity and a short pot life, so that dripping and outflow can be reduced, and the gaps in the junker, the gaps around the reinforcing bars, or the gaps in the joints can be filled well. be able to.

In addition, since it has high strength and moderate elongation after hardening, it can restore the strength of the structure and can follow deformation.

The epoxy-based filler according to the second invention is the epoxy-based filler according to the first invention, and has an elongation rate of 100% or less after curing.

Since the elongation after curing is 100% or less as described above, high strength and appropriate elongation can be obtained after curing.

The epoxy filler according to the third invention is the epoxy filler according to the first or second invention, wherein the epoxy filler has a viscosity of 100 to 2000 mPa·s at 23°C.

If it is lower than 100 mPa·s, fluidity is good, but the amount of penetration into concrete increases, and a large amount of resin is required in excess of the pore volume. If the viscosity is higher than 2000 mPa·s, the resistance increases, so that the filling range becomes narrow and the injection takes a long time.

By using a filler having such a viscosity, it is possible to satisfactorily fill the voids of the junker.

A method for repairing a concrete structure according to a fourth aspect of the present invention comprises using a two-liquid mixing discharge device for the epoxy-based filler according to any one of the first to third aspects of the invention, and Inject into the gap of the joint or the gap of the joint.

In this way, by injecting the epoxy-based filler of the present invention using a two-liquid mixing and discharging device, the resin is injected into the gaps of the junker (bean board), the gaps of the reinforcing bar period, or the gaps of the joints immediately after mixing. Since it has a low viscosity and quickly penetrates into voids and has a short pot life, dripping and outflow can be reduced, and the junker can be filled well.

In addition, since it has high strength and moderate elongation after hardening, it can restore the strength of the structure and can follow deformation.

A concrete structure repair method according to a fifth invention is the concrete structure repair method according to the fourth invention, wherein the concrete structure is a tunnel.

As a result, it is possible to repair gaps in junkers in tunnels, gaps around reinforcing bars, gaps in joints, and the like.

INDUSTRIAL APPLICABILITY According to the present invention, in the repair of a concrete structure, a two-liquid curing type epoxy filler capable of improving filling in gaps in junkers, gaps around reinforcing bars or gaps in joints, and the use thereof A method for repairing concrete structures can be provided.

Schematic diagram showing a state in which resin is being injected into the tunnel bean board (junka). FIG. 4 is a flow chart showing a method of repairing a tunnel bean board (Junka).

A two-liquid curing type epoxy filler according to an embodiment of the present invention will be described below with reference to the drawings.

(epoxy filler)
The epoxy-based filler of the present embodiment is filled to repair gaps in joints of concrete structures, gaps in junkers, or gaps around reinforcing bars.

The two-liquid curing type epoxy filler used in this embodiment contains a main agent and a curing agent. The main agent is an epoxy resin, including bisphenol A type epoxy resin and bisphenol F type epoxy resin. Curing agents include amine compounds. The epoxy-based filler of the present embodiment has a pot life at 23° C. of less than 15 minutes and an elongation after curing of more than 10%. Further, the elongation after curing is preferably 100% or less.

The viscosity at 23° C. of the epoxy-based filler of the present embodiment is preferably 100 to 2000 mPa·s. This facilitates ejection during filling.

The bisphenol F-type epoxy resin has a lower viscosity than the bisphenol A-type epoxy resin, so that it can be satisfactorily filled in the junker.

(Repair method using epoxy resin)
FIG. 1 is a diagram showing a state in which a junker 102 (bean board) inside an inner wall 101 of a track tunnel 100 is being repaired as an example of a concrete structure. FIG. 2 is a flow chart showing a method of repairing a tunnel slab (Junka). The tunnel 100 is not limited to a track tunnel, and may be a general road tunnel or a highway tunnel. Also, in this embodiment, a tunnel is used as an example of a concrete structure, but the structure is not limited to a tunnel, and may be a bridge, a road, or the like.

In FIG. 1, a gap portion is generated by a junction 102 inside an inner wall 101 of a tunnel 100 (an example of a concrete structure). Junka is one of the defects of track tunnel lining concrete. A slab is an initial failure affected by the fluidity of concrete and construction methods such as pumping during tunnel construction. The cause is the material separation due to the press-pumping with compressed air.

First, in step S10, an injection hole is drilled in inner wall 101 toward junker 102 . Then, in step S20, the resin injection pipe 1 is attached to the injection hole. Although the structure of the resin injection pipe 1 is not particularly limited, for example, it is cylindrical, and the static mixer 5 is attached to the opening at one end, and the resin is discharged from the opening at the other end.

Next, in step S30, the resin injection pipe 1 is connected to a two-liquid mixing and discharging device. Specifically, a static mixer 5 is connected to the resin injection pipe 1 . The static mixer 5 is connected to the injection device 7 via material transport hoses 6a, 6b. The injection device 7 is a two-liquid mixing and discharging device.

After the connection in step S30, in step S40, the injection device 7 injects the main agent and the curing agent at a predetermined ratio into the material transport hoses 6a and 6b, respectively. The discharged main agent and curing agent pass through the material transport hoses 6a and 6b and are conveyed to the static mixer 5. In the static mixer 5, the main agent and curing agent are stirred, and the stirred main agent and curing agent are injected. Jenga 102 is filled through pipe 1 .

Next, in step S50, the filled epoxy-based filler is left to harden.

Next, in step S60, the resin injection pipe 1 is broken inside the inner wall 101 of the tunnel 100 by hitting and breaking the portion of the resin injection pipe 1 protruding from the inner wall 101 with a stone head hammer or the like, and a sealing material is applied to the broken portion. is applied, and the injection hole is blocked.

Through the above operation, the junction 102 formed inside the inner wall 101 of the tunnel 100 can be repaired by injecting the epoxy-based filler into the junction 102 .

Next, it demonstrates using an Example.

In this example, the type of filler was changed and the compressive strength and repeated fatigue test were evaluated.

In Example 1, a two-liquid mixed epoxy resin was used as the filler.
Bisphenol F-type epoxy resin, bisphenol A-type epoxy resin, and 1,6-hexanediol diglycidyl ether were used as main agents, and the ratio was adjusted so that the viscosity was 800 mPa·s. Epoxy equivalent weight was 173 g/eq. An amine compound containing meta-xylene diamine was used as a curing agent, and the viscosity was adjusted to 400 mPa·s. The amine value was 324 mgKOH/g. The mixing ratio of the main agent and the curing agent is by weight, and the ratio of the main agent to the curing agent is 2:1. The mixture has a viscosity of 550 mPa·s, a pot life of 11 minutes, and a tensile elongation at break of 23% after hardening and curing for 1 week at 23°C.

In Comparative Example 1, a product name: DK550-003 manufactured by Denka Co., Ltd. was used as a filler. DK550-003 contains acrylic, has a viscosity of 240 mPa·s, a pot life of 17 minutes, and a tensile elongation at break of 3% after curing for 1 week at 23°C.

In Comparative Example 2, Konishi Co., Ltd. product name: Bond E206S was used as the filler. E206S contains bisphenol F type epoxy resin and bisphenol A type epoxy resin, has a viscosity of 580 mPa s, a pot life of 34 minutes, and a tensile elongation at break after curing for 1 week at 23 ° C. 7%.

In Comparative Example 3, a product name: Infraguard CRJ manufactured by Sekisui Chemical Co., Ltd. was used as the filler. CRJ contains a bisphenol A type epoxy resin, has a viscosity of 725 mPa·s, a pot life of 115 minutes, and a tensile elongation at break of 122% after curing and curing for 1 week at 23°C.

The results are shown in (Table 1).
Viscosity, pot life, elongation (tensile elongation at break), and compression strength were evaluated according to JIS A6024.
A cyclic fatigue test was performed using a servo pulser EHF-ED1KNX4-4LA (manufactured by Shimadzu Corporation) with a small dumbbell test piece under the following conditions. Frequency: 1Hz, Waveform: Sine wave, Temperature: 23°C, Displacement: 1.5%

（表１）より、可使時間が１５分以下であり、伸び率が１０％超である実施例１において、圧縮強さおよび繰り返し疲労試験ともに良好となることがわかる。

From Table 1, it can be seen that in Example 1, in which the pot life is 15 minutes or less and the elongation is more than 10%, both the compressive strength and the repeated fatigue test are good.

According to the two-liquid curing type epoxy filler and the method for repairing a concrete structure using the same of the present invention, it has the effect of improving filling in gaps such as junkers, and has high strength. It is useful for repairing tunnels, etc., because it also has the ability to follow deformation.

5: Static mixers 6a, 6b: Material transport hose 7: Injection device 100: Tunnel 101: Inner wall 102: Junker

Claims (5)

A two-liquid curing type epoxy filler for injection into gaps in junkers of concrete structures, gaps around reinforcing bars, or gaps in joints,
An epoxy filler whose pot life at 23° C. is less than 15 minutes and whose elongation after curing is greater than 10%. 2. The epoxy-based filler according to claim 1, which has an elongation of 100% or less after curing. The epoxy filler has a viscosity of 100 to 2000 mPa s at 23 ° C.
The epoxy-based filler according to claim 1 or 2. The epoxy-based filler according to any one of claims 1 to 3 is injected into gaps in the junction of concrete structures, gaps around reinforcing bars, or gaps in joints using a two-liquid mixing discharge device. , a method for repairing concrete structures. wherein the concrete structure is a tunnel;
The method for repairing a concrete structure according to claim 4.

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