JP3435493B2 - Concrete repair method and partial heating device for standing concrete wall - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for repairing concrete.

[0002]

2. Description of the Related Art Conventionally, when repairing a damaged portion such as a crack or a deteriorated portion of concrete, it occurs after scraping the damaged portion with a vibrating tool whose power source is compressed air pressure, hydraulic pressure, or electricity. A method of filling a hollow with a repair material and fixing the filled repair material to the concrete surface by its adhesive force to restore the original shape has been continuously adopted.

The above-mentioned dent formed by cutting concrete causes cracks in aggregate and mortar by vibrating tools using concrete as a power source of compressed air pressure, hydraulic pressure, or electricity. Since it has occurred, the surface of the depression is generally smooth.

Therefore, there is a problem that when the repair material filled in the dent shrinks and separates from the surface of the concrete, the repair material easily falls off. Also,
When the coefficient of thermal expansion of concrete and the coefficient of thermal expansion of the repair material after fixation are different, there is a problem that the repair material peels off from the concrete due to the difference in thermal expansion due to the temperature and easily falls off.

In order to solve the above problems, when the damaged portion of concrete is shaved off, the concrete is scraped off until the back side of the reinforcing bar is exposed, and the reinforcing material is entangled with the reinforcing material to fill the resulting depressions. A method has been continuously adopted in which the peeling does not easily come off even if peeled.

However, when the concrete is scraped off until the reinforcing bars are exposed, if the adhered repair material is peeled off due to contraction or thermal expansion difference, the surface of the hollow of the concrete where the repair material is located is generally smooth, A phenomenon occurs in which rainwater or air enters deep inside the gap created by peeling and corrodes the reinforcing bar. If the reinforcing bar corrodes, there is a problem that the reinforcing bar expands in volume, causing peeling and dropping of the repaired part and a sound concrete part adjacent thereto.

Due to the above circumstances, the adhered repair material peels off.
The advent of a repair method that does not fall off has been eagerly awaited by the parties concerned.

[0008]

[Problems to be solved] Make sure that the repaired part of concrete does not fall off even if it peels off.

[0009]

Heating the damaged portion and its periphery of the concrete [SUMMARY OF] and brittle, by that removing the fragile portion, with extinguish the lesion, rich in irregularities caused by its removal By filling the excavation ditch with the repair material, the repair material and the concrete are intricately mixed with each other so that the repair material does not fall off even if peeled off.

[0010]

DETAILED DESCRIPTION OF THE INVENTION

Concrete is a mixture of aggregate, sand, cement, and water, which is solidified by the hydration reaction of alumina, which is a cement component, so that "free water", which is the water remaining in the hydration reaction, is solidified. And "hydrated water" which is water of crystallization.

The solidified concrete is a mixture of aggregate, sand and mortar because the mortar is a solidified mixture of cement and water.

Therefore, by heating the mortar in the damaged part such as cracks and deteriorated parts generated in the solidified concrete and its surroundings (hereinafter referred to as "repair part") to 300 ° C. or higher, free water in the repair part and The water of crystallization is turned into high-pressure steam and released from inside the concrete. The expansion pressure of these water vapors causes minute cracks in the mortar to be released from the inside of the concrete, thus weakening all the mortars existing in the repaired portion. Therefore, 300 ° C
The mortar on the heating side, the so-called surface side, becomes brittle at a temperature higher than 300 ° C, and the mortar on the non-heating side, so-called concrete 1 is lower than 300 ° C. If you are healthy.

Then, the mortar of the weakened concrete portion is subjected to ultrasonic engraving knife, vibrating wire-shaped chisel, vibrating spatula-shaped chisel or the like (hereinafter referred to as "vibratory cutting machine").
Powder the fragile mortar using, and scoop out the aggregate. A groove (hereinafter referred to as an "excavation groove") is provided in the repaired portion by removing the aggregated material, the powdered mortar, and the sand contained in the mortar. 300 ° C
Since the mortar on the non-heating side of the isotherm is not weakened, some of the aggregates located on the isotherm of 300 ° C. can remain without being dug out. For this reason,
The inner surface of the trench will be uneven.

The width of the repaired portion is at least about 50 when the maximum aggregate has a size of 30 mm to 40 mm.
It is necessary to make the aggregate more than mm so that the aggregate can be easily removed. Therefore, for repairing cracks, the minimum width of the excavation groove is preferably at least about 50 mm. In addition, for repairing the neutralized part and the mortar lacking part due to poor mixing at the time of initial concrete placement, the remaining part between the grooves created after arranging the excavation grooves in parallel at small intervals is cracked and removed. By this, a wide excavation trench is provided.

Of the aggregates protruding to the inner surface of the excavation trench, the aggregate that can be pulled out is extracted to make the inner surface uneven, and then the excavation trench is filled with the repair material. Therefore, in the method for repairing concrete according to the present invention, the solidified repair material fits into the concavities and convexities located on the inner surface of the excavation groove and is entangled in the concrete, and therefore does not fall off even if peeling occurs. Further, in the method for repairing concrete according to the present invention, even if the repair material is peeled off, since the repair material and the concrete are intricate, it becomes difficult for rainwater and air to penetrate deep into the gap, and corrosion of the rebar is made difficult. There is an effect. Furthermore, the concrete repairing method according to the present invention has an effect of making it difficult for neutralization of concrete to occur inside since rainwater and air are difficult to penetrate deep into the gap even if the repairing material is peeled off.

It should be noted that, according to the knowledge obtained in the practice of the present invention, the concrete is located at a position 2 below the center of the heating element.
Approximately 7.5 per minute inside the concrete 5 mm away
No explosion occurred even when the temperature was continuously raised at a rate of 60 ° C. for 60 minutes. The heat generating capacity of the heat generating element in this case was 600 W per 300 mm of heat generating element length. Therefore, the temperature rise to weaken the concrete is 2
Inside the concrete 5 mm apart, about 7.
It is preferable to continuously raise the temperature at a rate of 5 ° C. for up to 60 minutes from the viewpoint of the safety of the worker and the efficiency of promoting the work.

[0018]

Embodiment 1 FIG. 1 is a heating element 3 which is placed on the crack 9 which aggregate is located in the surface 2 of the concrete 1, which consists of crushed stone, heat is generated are covered with heat shield 4, FIG. 6 is a cross-sectional view showing a situation where points A and B, which are positions on the surface 2 approximately 25 mm away from the surface position C under the center of the heating element 3, are heated to 300 ° C.

A heat insulating material is attached to the inner surface of the heat shield cover 4 so that the radiant heat from the heating element 3 is not released to the atmosphere. 5 in FIG. 1 represents an isotherm at 300 ° C.,
The isotherm 5 is generated by the heating element 3 generating heat of 600 W per 300 mm length over 60 minutes. Figure 1
Reference numeral 6 denotes a shaded portion in the figure, which represents a weakened portion caused by dehydration of the mortar 7 located inside the isotherm 5, and the width of the uppermost portion of the weakened portion 6, that is, the surface of the concrete 1. The width of the fragile portion in 2 is between the points A and B, which is a position of 300 ° C., and is about 50 mm.

The heating by the heating element 3 is stopped in the situation shown in FIG. 1, that is, when the temperature of the surface 2 at a distance of about 25 mm from the surface position below the center of the heating element 3 rises to 300.degree.

After the heating is stopped, the excavation groove 10 is provided by pulverizing the mortar 7 located in the fragile portion 6 of the concrete 1 with a vibrating cutting machine to remove crushed stones, sand and powdered mortar. You can Of the crushed stones 8 protruding to the bottom of the excavation trench 10, the fragile portion 6 travels along the crushed stone 8 to the non-heating side, that is, the sound portion 13 side, so that the crushed stone 8 that is easily pulled out is removed. .

Since the width of the fragile portion 6 on the surface 2 of the concrete 1 is about 50 mm, the crushed stone 8 having a size of 30 mm to 40 mm or less located in the fragile portion 6 is a mortar vibrating and cutting machine 12. It can be pulverized and removed.

Therefore, since the crushed stone traces 15 and the remaining crushed stones 16 are located on the inner surface of the excavation groove 10 formed by removing the fragile portion 6 and the crushed stone 8, the surface becomes rich in unevenness. Next, the repair material 11 is filled in the excavation groove 10 to restore the surface 2 of the kuncrete 1 to the surface without the cracks 9, whereby the repair is completed. The repair material 11 that is filled and hardened in the excavation groove 10 fits into the concavities and convexities present on the inner surface of the excavation groove 10 as shown in FIG. Further, the edge of the crushed stone trace portion 15 located on the inner surface of the excavation groove 10 is not a square because the fragile portion 6 is a trace along which the fragile stone portion 6 has traveled to the non-heating side, that is, the healthy portion 13 side. Therefore, the repair material 11 is replaced with the excavation groove 10
It is possible to completely fill the inner surface of the container and to fill it.

When the repair material 11 is filled in the trench 10 after applying the sodium thiosulfate 14 to the surface of the trench 10 on the vertical wall, there are crushed stone traces 15 capable of accumulating the sodium thiosulfate 14. , The crushed stone trace part 1
By filling the repair material 11 after accumulating the sodium thiosulfate 14 in 5 the sodium thiosulfate 14 can be spread to the inner surface of the excavation groove 10 by the pressure of the repair material 11. The sodium thiosulfate 14 that has spread to the inner surface of the excavation trench 10 is soaked in and accumulated in the concrete 1, so that the sodium thiosulfate 14 activates the inner surface of the excavation trench 10 for a long period of time. The strength after repair can be improved as compared with the case where 14 is not applied.

[0025]

[Embodiment 2] FIG. 3 is a cross-sectional view showing a repair situation when a deep crack 17 is present on the surface 2 of concrete 1 whose aggregate is made of crushed stone. Reference numeral 18 in FIG. 3 denotes an excavation groove, and the excavation groove 18 is the surface 2 of the concrete 1.
After the heat-generating body 3 (indicated by a chain double-dashed line) placed on the crack 17 (indicated by a chain double-dashed line) is covered with the heat shield cover 4 to generate heat, the fragile portion of the mortar 7 and the fragility thereof caused by the heat generation This is caused by removing the crushed stone 8 in the section. Figure 3
The heating element 3 indicated by the solid line inside, that is, the heating element 3 placed on the crack 17 located at the bottom of the excavation groove 18
Puts the heat shield cover 4 on the edge of the excavation groove 18 to generate heat, and weakens the mortar 7 in the isotherm 19 at 300 ° C. The shaded portion in the figure represents the fragile portion 20 within the 300 ° C. isotherm 19 of the concrete 1. In the above-mentioned situation, that is, when the position at a distance of approximately 25 mm from the heating element 3 is heated to 300 ° C., the heating by the heating element is stopped.

After the heating is stopped, the mortar 7 in the fragile portion 20 of the concrete 1 is pulverized by the vibration cutting machine 12,
By removing crushed stones, sand, and pulverized mortar and digging down, a digging groove 21 is provided in which the digging groove 18 is deepened. Of the crushed stones 8 protruding at the bottom of the excavation groove 18, the crushed stones 8 that can be pulled out are pulled out and removed. Next, the repair material 11 is applied to the excavation groove 21 formed by deepening the excavation groove 18 as shown in FIG.
Repair is completed by filling and restoring the surface 2 of the concrete 1 to the surface without cracks 17 as shown in FIG.

Since the solidified repair material 11 is deeply filled, the area for fitting with the irregularities on the inner surface of the excavation groove 21 becomes large, and the peeling phenomenon hardly occurs. Therefore, this repair method is suitable for crack repair in a concrete structure to which a vibration load is applied.

[0028]

[Third Embodiment] FIG. 5 shows a case in which the depth 25 of the excavation groove 24 provided on the surface 23 of the vertical wall 22 of the concrete 1 is further deepened by excavation, as if the excavation groove 18 was deepened. Partial heating device A for standing concrete wall
FIG. 3 is a partial cross-sectional perspective view showing a state in which the heating element 26 is installed in the bottom 25 when installed in FIG. 1, and the partial heating device A for the standing concrete wall in the drawing is the heating element 26 and the heating element support means 2.
7 and the heat shield cover 35.

The heating element support means 27 is composed of a projecting plate 30 having a support cylinder 29 made of an insulator at its center, and both ends thereof supported by flanges 31a and 31b with webs.
As shown in FIG. 5, the heat shield cover 35 is sandwiched from above and below, and the flange portions of the concrete 1
It is brought into contact with the vertical wall 22 and is attached and fixed to the vertical wall 22 with an adhesive tape 28. Flange with web 31a, 3
Since the surface 23 of the concrete 1 is heated by the heat generated by the heating element 26, the length 1b is long so that the adhesive tape 28 can be attached to a temperature range where the adhesive force does not decrease due to the influence of temperature.

The heating element 26 is formed in a [letter shape, the straight line portion is along the heating target portion of the concrete 1, and each of the hook portions 32 is inserted into the support cylinder 29 of each heating element support means 27. In the heating element 26, since the protruding plate 30 having the support cylinder 29 protrudes from the flanges 31 a and 31 b with the web, the hook portion 32 is moved out of the support cylinder 29 so that the straight line portion extends along the surface 23 of the concrete 1. Since it can be made to heat, the surface 23 of the concrete 1 can also be heated.

The heat insulating cover 35 has a heat insulating material affixed to the concrete side of the inner surface, and its cross-sectional shape is the same as that of the heating element supporting means 27 as shown in FIG.
Since the heat shield cover 35 is configured as described above, the projecting portion at the central portion is the concrete 1 which is the heating target portion of the concrete 1.
It is fixed to the surface 23 of the concrete 1 by covering the surface 23 and the excavation groove 24, sandwiching the upper and lower parts with two heating element support means 27.

Since the partial heating apparatus A for the standing concrete wall according to the present invention has the above-mentioned configuration, the heating element 26 is used as the excavation groove 2.
The two heating element supporting means 27, in which the heating elements 26 are assembled so as to be located along the crack located at the bottom of the bridge 4, are bridged on the excavation groove 24 at intervals of the length of the heat shield cover 35. And the flanges 31a and 31b with webs, respectively.
Is attached to the vertical wall 22 with an adhesive tape 28.

Instead of using the adhesive tape 28, the contact surfaces of the flanges 31a and 31b with webs may be fixed to the concrete surface 23 with double-sided adhesive tape. Thus, the heating element 26 can be installed at the bottom 25 of the vertical excavation groove 24. And the heat shield cover 35
Is pushed between the heating element support devices 27, and the excavation groove 24 is covered with the heat shield cover 35.

Next, after the heating element 26 is electrically heated to weaken the bottom 25 of the excavation groove 24, the heat shield cover 35, the heating element support device 27, and the heating element 26 are removed to remove the excavation groove 18 below. The fragile portion 20 is removed to remove the fragile portion 33 at the back of the inner bottom 25 in the same manner as the deep excavation groove 21 is provided. Thus, a deep excavation groove 34 can be provided in the surface 23 of the vertical wall 22 of the concrete 1.

Next, the repair material 11 is filled in the excavation groove 34 formed by deepening the excavation groove 24, and the surface 2 of the vertical wall 22 of the concrete 1 is restored to a crack-free surface, whereby the repair is completed. . Since the solidified repair material 11 is deeply filled, the area to be fitted with the irregularities on the inner surface of the excavation groove 34 becomes large, and the peeling phenomenon hardly occurs.
Therefore, this repairing method is suitable for repairing cracks generated in a vertical wall in a concrete structure to which a vibration load is applied.

The heating of the vertical wall 22 for excavating the original excavation groove 24 is performed by the above-mentioned two heating element support means 2
7 and the heating element 26. The height of the protruding plate 30 provided with the support cylinder 29 in the heating element support means 27 from the flanges 31a and 31b with the web is set in advance to the height at which the heating element 26 can be accommodated. The two heating element support means 27 supporting the heating element 26 are positioned so that the heating element 26 is installed along the cracks on the surface 23 of the concrete 1, and these flanges 31a and 31b with all webs are attached. It is fixed to the vertical wall 22 of the concrete 1 with the adhesive tape 28. Next, the heat shield cover 35 is pushed between the heating element support means 27 and the heating element 26 is energized to heat the surface 23 of the vertical wall 22.

Therefore, after heating as described above, the adhesive tape 28 is peeled off, and the heat shield cover 35 and the heating element support device 2 are provided.
By removing the heating element 26 and the heating element 26 and then removing the portion weakened by heating, a vertical excavation groove 24 can be provided in the surface 23 of the vertical wall 22.

Further, in the present embodiment, the excavation groove 24 is provided vertically to the vertical wall 22, but the excavation groove 24 is provided with the heating element support means 27 side by side so that the heating element 2 can be installed.
Since 6 can be provided sideways, it can be provided sideways. However, when the excavation groove 24 is provided laterally, the heating element support means 27 is slightly inverted into a concrete shape.
To prevent the heat shield cover 35 from falling off.
Then, since the heating element 26 pushes the hook portion 32 into the inside of the support tube 29, the straight portion can be made to follow the inner bottom 25 of the excavation groove 24, so that the excavation groove 24 is further deepened and the excavation groove 34 is provided. be able to. Similarly to the above, by obliquely providing the heating element 26, it is possible to obliquely form the excavation groove 24 in the vertical wall 22, and to make the oblique excavation groove 24 into the deep excavation groove 34 in the same manner as described above. You can

[0039]

[Effect] The “concrete repair method” according to the present invention is
As mentioned above, even after the repair material has peeled off, the repair material does not drop out, and the repair material does not fall off and continues to protect the concrete from corrosion of reinforcing bars and progress of neutralization of concrete. Have. Further, the "method for repairing concrete" according to the present invention uses a crushing device using a shock of a weight that uses compressed air, hydraulic pressure, or electricity as a power source, a so-called rock drill or breaker, or the like. Since the concrete is not ground, no large noise is generated by these devices. In the “method for repairing concrete” of the present invention, fragile mortar is pulverized by an oscillating cutting machine to remove the damaged portion and its peripheral portion, so that noise is extremely low. For this reason, even if the office is in operation, even if there are inpatients in the hospital, it is possible to repair the concrete portion of such a building.

Further, in the "method for repairing concrete" of the present invention, since the repair material is deeply filled and the inner surface of the filling hole of the repair material is rich in unevenness, a concrete structure to which a vibration load is applied is applied. Suitable for repairing cracks on objects.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a heating element is installed on the surface of concrete, and the surface of the concrete and the lower part of the surface are weakened.

FIG. 2 is a cross-sectional view of a state in which a repair material is filled in an excavation groove to repair a crack in shallow concrete.

FIG. 3 is a cross-sectional view showing a state in which a heating element is installed on the surface of concrete and the lower part of the bottom surface of the excavation groove provided in concrete is weakened.

FIG. 4 is a cross-sectional view of a state where a deep crack in concrete is repaired by filling the excavation groove with a repair material.

FIG. 5 is a perspective view showing a situation in which a partial heating device is attached to an erected concrete wall to provide an excavation groove.

[Explanation of symbols]

A ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ Concrete area 2
Surface 3 ‥‥‥‥‥‥ Heating element 4 ‥‥‥‥‥‥‥‥‥‥‥‥‥
Heat shield cover 5 ‥‥‥‥‥ Isotherm 6 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥
Fragile part 7 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥
Crushed stone 9 ‥‥‥‥‥ Crack 10 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥
・ ・ ・ Drilling trench 11 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥
Excitation cutting machine 13 ‥‥‥‥‥ Sound part 14 ‥‥‥‥‥‥‥‥‥‥
Sodium thiosulfate 15 …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
Residual crushed stone 17 ‥‥‥‥‥ Crack 18 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥
・ ・ ・ Drilling groove 19 ‥‥‥‥‥ Isotherm 20 ‥‥‥‥‥‥‥‥‥‥
Vulnerable part 21 ‥‥‥‥‥ digging groove 22 ‥‥‥‥‥‥‥‥‥‥‥
・ ・ ・ Vertical wall 23 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥
・ ・ ・ Drilling groove 25 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥
・ ・ ・ Heating element 27 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥
Adhesive tape 29 ... Support tube 30 ...
・ ・ ・ Projection plates 31a, 31b ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ Hook part 33 ‥‥‥‥‥‥‥‥‥‥‥‥
Fragile part 34 ‥‥‥‥‥‥‥ digging groove 35 ‥‥‥‥‥‥‥‥‥
Heat shield 36, cross section

Claims (2)

(57) [Claims] 1. A concrete surface around a damaged portion is removed.
By providing a recess on the surface of the concrete,
In the concrete repair method that fills the repair area with the repair agent
The heating element placed on the crack on the concrete surface.
Inside the heating element by heating the concrete surface
Inside the concrete 25 mm away from the surface below the center
Of the heating element at a rate of about 7.5 ° C. per minute.
Of concrete about 25mm away from the surface position under the center
When the surface temperature rises to 300 ° C, heating is stopped and raw
The fragile portion is removed by pulverizing the mortar in the weakened portion, and the mortar remains at the position that was the isotherm at 300 ° C.
The remaining crushed stones and the crushed stone traces generated by extracting the crushed stones
The excavation groove is rich in unevenness and the repair agent is fitted into the unevenness.
A method for repairing concrete, characterized by filling the excavation groove . 2. A heating element support means (27) comprising a protrusion at the center and flanges (31a, 31b) with webs at both ends, and a heat shield cover (3) having the protrusion at the center.
5) is sandwiched between the upper and lower sides, and the [shaped heating element (26)
Each of the hook portions (32) of the heating element support means (27) is inserted into the protruding portion of the heating element supporting means (27), and the straight portion of the heating element (26) is aligned with the heating target portion of the concrete (1). All the flanges with the web (31a, 31b) on the adhesive tape (2
Partial heating device for standing concrete wall, characterized in that it is attached to the surface (2) of concrete (1) in 8).