JP7488983B2 - How to repair a transverse tooth joint - Google Patents

Description

The present invention relates to a method for repairing transverse tooth joints that are formed at the joints of road foundations such as bridges and elevated roads and absorb the expansion and contraction of the road foundations.

Joints are installed at the joints of road foundations such as bridges and elevated roads in order to absorb expansion and contraction of the road foundation due to temperature changes and to prevent rainwater from penetrating into the interior of the bridge, etc.
The joint comprises a joint body formed in a groove shape, a water-stopping material that is fitted into the inside of the joint body, and concrete sections that are constructed on both sides of the joint body in the longitudinal direction of the road (see, for example, Patent Documents 1 and 2).

At least the upper portion of the joint body is groove-shaped with metal walls spaced apart and facing each other.
Moreover, the joint body has a wave shape in a plan view, and the joint portion as a whole has a generally comb-tooth shape in a plan view.

The width of the groove-like gap formed by the separation of these walls is, for example, about 70 mm in winter, but in summer, as a result of the road base expanding due to heat, the width of the gap narrows to about 30 mm.

To put it another way, in winter when the gap width widens, the water-stop material installed inside the joint body is under tension, which acts in a direction that pulls the water-stop material away from the wall of the joint body.

Here, the water-stopping material of the joint deteriorates over many years of use, and the water-stopping material may break or peel off from the joint body.
If the waterproofing material breaks in this way, rainwater will seep into the bridge, causing rust and significantly reducing the service life of the bridge.

To address this issue, in the past, the concrete or road base was cut and most of the joints were replaced during regular maintenance.
However, such a replacement method is very wasteful and undesirable not only from a cost perspective but also from an environmental perspective.
Here, the applicant has filed an application for a method of repairing a joint (Patent Document 3).

JP 2006-29069 A JP 2014-218819 A JP 2018-204265 A

However, the invention described in Patent Document 3 relates to vertical tooth joints and cannot be directly applied to horizontal tooth joints.

Furthermore, in the case of horizontal tooth joints, if there is no existing backup material or if the existing backup material has fallen off, it is difficult to install new backup material due to the nature of horizontal tooth joints, which have a small opening at the top, and therefore it is also difficult to fill with water-stopping material.

The object of the present invention is to provide a method for repairing transverse tooth joints that can repair transverse tooth joints even if no existing backup material exists or if the existing backup material has fallen off.

In order to achieve the above object, a method for repairing a transverse tooth joint according to claim 1 of the present invention includes the steps of:
A method for repairing a transverse tooth joint in which wall portions (10) extending substantially vertically face each other and are spaced apart to form a first gap (S1), and protruding portions protruding from upper ends of the respective wall portions (10) in a facing manner are spaced apart to form a second gap (S2), an existing seal material (40) is provided in the first gap (S1), and no existing back-up material exists below the existing seal material (40) or the existing back-up material has fallen off, comprising:
an existing seal material removing process (300) for inserting a blade through the second gap (S2) to cut the central portion of the existing seal material (40) to a width approximately equal to the width of the second gap (S2) and removing the cut central portion of the existing seal material (40);
a new back-up material arrangement process (400) for inserting a new back-up material (60, 61, 62) into the first gap (S1) from the outside and arranging the new back-up material (60, 61, 62) in an upper part of the first gap (S1);
A water-stopping material filling step (700) of filling a water-stopping material (50) between the existing sealing materials (40) from which the central portions have been removed and into the second gap (S2);
and a hardening step (800) of hardening the filled water-stopping material (50).

The repair method for a transverse tooth joint according to claim 2 further comprises the steps of:
In the newly installed backup material placement process (400), the newly installed backup material (60) is an expandable expansion body (62), and the expansion body (62) is inserted into the first gap (S1) through the second gap (S2) and expanded to support the expansion body (62) at an upper portion of the first gap (S1).

The repair method for a transverse tooth joint according to claim 3 further comprises the steps of:
In the newly installed backup material placement process (400), the newly installed backup material (60) is a plate material (61), and the plate material (61) is inserted into the first gap (S1) through the second gap (S2), and the upper surfaces of both short-side edge portions of the plate material (61) are attached to the lower surface of the existing sealing material (40) from which the central portion has been removed.

Here, the symbols in parentheses above indicate the corresponding elements or items shown in the drawings and in the detailed description of the invention described below.

According to the present invention, a new backup material is inserted into the first gap from the outside, the new backup material is placed on top of the first gap, and a water-stopping material is filled between the existing sealing material from which the central portion has been removed and into the second gap. Therefore, even in the case of a horizontal tooth joint where no existing backup material exists or where the existing backup material has fallen off, it is possible to repair the joint without replacing the entire joint.
In particular, since the new backup material is placed in the upper part of the first gap, the amount of water-stopping material used is small, making repairs inexpensive.

The above-mentioned Patent Documents 1 to 3 do not mention at all the repair method of the present invention for a transverse tooth joint, in which the center of the existing sealing material is removed, a new backup material is inserted from the outside, and a water-stopping material is then filled in.

FIG. 2 is a cross-sectional view showing a transverse tooth joint. FIG. 2 is a plan view showing a transverse tooth joint. FIG. 2 is a process diagram showing a repair method for a transverse tooth joint according to the first embodiment of the present invention. 1 is a cross-sectional view of a transverse tooth joint showing the existing sealant removal process in a repair method for a transverse tooth joint according to a first embodiment of the present invention. FIG. 1 is a cross-sectional view of a transverse tooth joint showing the step of placing a new backup material in the repair method for a transverse tooth joint according to the first embodiment of the present invention, showing the state in which a backup plate material is inserted from the outside. FIG. 1 is a cross-sectional view of a transverse tooth joint showing a newly installed backup material placement process in a repair method for a transverse tooth joint according to a first embodiment of the present invention. FIG. 4 is a cross-sectional view of a transverse tooth joint showing a water-stopping material filling step in the repair method for a transverse tooth joint according to the first embodiment of the present invention. FIG. 1 is a cross-sectional view of a transverse tooth joint showing an upper surface resection process in a repair method for a transverse tooth joint according to a first embodiment of the present invention. FIG. 11 is a plan view showing a newly installed backup material (backup plate material) for a repair method for a transverse tooth joint according to a second embodiment of the present invention. FIG. FIG. 10 is a front view of the newly installed backup material (backup plate material) of FIG. 9 . 11 is a cross-sectional view of a transverse tooth joint showing the step of placing a new backup material in a repair method for a transverse tooth joint according to a second embodiment of the present invention, showing the state in which a backup plate material is inserted from the outside. FIG. 11 is a cross-sectional view of a transverse tooth joint showing the newly installed backup material placement process in the repair method for a transverse tooth joint according to a second embodiment of the present invention, showing the state in which a backup plate material has been inserted into the first gap. FIG. 11 is a cross-sectional view of a transverse tooth joint showing the newly installed backup material placement process in the repair method for a transverse tooth joint according to a second embodiment of the present invention, showing the state in which the backup plate material has been pulled up. FIG. FIG. 11 is an enlarged view of a backup plate showing the step of placing a new backup material in the repair method for a transverse tooth joint according to a second embodiment of the present invention, illustrating a method for sufficiently adhering the backup plate to the existing sealant. 6 is a cross-sectional view of a transverse tooth joint showing a water-stopping material filling step in a repair method for a transverse tooth joint according to a second embodiment of the present invention. FIG. A cross-sectional view of a transverse tooth joint showing an upper surface resection process in a repair method for a transverse tooth joint according to a second embodiment of the present invention.

First Embodiment
A method for repairing a transverse tooth joint 1 according to a first embodiment of the present invention will be described with reference to Figs.
The repair method for the transverse tooth joint 1 in this embodiment includes a foreign matter removal process 100, a suction process 200, an existing sealing material removal process 300, a new backup material placement process 400, a rust prevention process 500, a primer application process 600, a water-stopping material filling process 700, a hardening process 800, and an upper surface resection process 900.

First, the structure of the transverse tooth joint 1 will be described.
The transverse tooth joint 1 is formed at the joints of road foundations such as bridges and elevated roads to absorb the expansion and contraction of the road foundations, and comprises a wall portion 10, a protrusion portion 20, and an existing sealing material 40.
In addition, in this transverse tooth joint 1, below the existing sealing material, there is no existing backup material for installing the existing sealing material, either because it has fallen off or for some reason it did not exist from the beginning.

The walls 10 extend substantially vertically, facing each other and spaced apart to form a first gap S1.

The protruding portions 20 protrude from the upper ends of the respective wall portions 10 in a mutually opposing relationship. The protruding portions 20 are spaced apart from each other to form a second gap S2. The first gap S1 and the second gap S2 are in communication with each other vertically.
An existing seal material 40 is provided on the upper portion of the first gap S1. The existing seal material 40 is disposed so as to be in contact with the lower surface of the protruding portion 20.

2, the protruding portion 20 is wavy in plan view, and the transverse joint 1 as a whole is generally comb-shaped in plan view. This wavy or generally comb-shaped shape in plan view is because the protruding amount of the protruding portion 20 increases or decreases depending on the position of the transverse joint 1.
Further, the direction in which the transverse tooth joint 1 extends is substantially perpendicular to the direction in which the road extends.
When the road base expands or contracts, the widths of the first gap S1 and the second gap S2 of the transverse tooth joint 1 change accordingly to absorb the expansion or contraction, thereby preventing unevenness or cracks from occurring in the road base.

The difference between the transverse tooth joint 1 and the longitudinal tooth joint is whether or not the transverse tooth joint 1 has a protrusion 20 .
In addition, a concrete section is arranged on the outside of the transverse tooth joint 1 in the direction in which the road base extends, and the concrete section has a metal plate or steel frame inside, fixing the transverse tooth joint 1 and filling the gap between the transverse tooth joint 1 and the road base.
In the following, the terms "outside" and "inside" generally refer to the outside and inside in the direction in which the road infrastructure extends.

Next, a method for repairing the transverse tooth joint 1 will be described with reference to FIG. 1 and FIGS.
First, in a foreign matter removal step 100, foreign matter adhering to the protrusion 20 is removed.
In this embodiment, blasting is used as a method for removing foreign matter. More specifically, an abrasive is sprayed onto the inner tip 20a of the protrusion 20 using a blasting device (not shown) to scrape off rust and dirt on the inner tip 20a of the protrusion 20.
By performing blasting when there is an existing sealing material 40, the abrasive material from the blasting does not fall to the ground.

Next, in the suction step 200, the abrasive sprayed in the foreign matter removal step 100 and the resulting dust are sucked up.
Here, the foreign matter removal step 100 and the suction step 200 may be performed simultaneously. That is, by spraying the abrasive and simultaneously suctioning the abrasive and the generated dust, the scattering of the abrasive and the dust can be minimized.

Next, in the existing sealant removal process 300, a blade is inserted through the second gap S2 to cut the central portion of the existing sealant 40 to a length approximately equal to the width of the second gap S2.
In other words, a blade is inserted at a position where it is just about to hit the inner tip 20a of the protrusion 20, and the central portion of the existing sealing material 40 is cut so as to maximize the width of the central portion of the existing sealing material 40 that will then be removed.

Then, the central portion of the cut existing sealing material 40 is pulled out using pliers or a rod-shaped object and removed as shown in FIG.
That is, the existing sealing material 40 is not completely removed here.

Next, in the new back-up material placement step 400, the new back-up material 60 is vertically crushed and inserted into the first gap S1 via the second gap S2 as shown in FIG.
This new backup material 60 is an expandable body 62 that can be expanded by introducing air, and is a balloon-like straight tube that extends in the direction in which the lateral tooth joint 1 extends.

6, the expansion body 62 is expanded and supported at the upper part of the first gap S1. At this time, the expansion body 62 is in pressure contact with the wall portion 10 and the lower surface of the existing sealing material 40 from which the central portion has been removed.
In other words, in this state, the expansion body 62 expands and presses against the wall portion 10, so that even if the expansion body 62 is released from the hand, the expansion body 62 will not fall from the upper part of the first space S1.

In this way, the expansion body 62 is expanded and supported at the top of the first gap S1, so that the water-stopping material 50 can be filled in the subsequent water-stopping material filling process 600.

Next, in the rust prevention process 500, a rust inhibitor is applied to the inner tip 20a of the protrusion 20 of the lateral tooth joint 1.

Next, in the primer application process 600, a primer is applied to the inner tip 20a of the protrusion 20 of the transverse tooth joint 1 to improve adhesion and durability between the water-stopping material 50 and the inner tip 20a of the protrusion 20.

Next, in a water-stopping material filling step 700 as shown in FIG. 7, the water-stopping material 50 is filled into the portion of the existing sealing material 40 from which the central portion has been removed and into the second gap S2.
At this time, the water-stopping material 50 is applied so as to be in close contact with the inner tip 20a of the protruding portion 20 and to protrude above the upper surface of the protruding portion 20. The height of the water-stopping material 50 excluding this protruding portion is 50 mm.
The waterproofing material 50 used here is a two-component silicone rubber having an elongation of 1700% or more and a tensile stress of 0.07 N/ ^mm2 .

Next, in the hardening process 800, the filled water-stopping material 50 is left to harden. In this embodiment, the water-stopping material 50 hardens in about 15 minutes.

Next, in an upper surface cutting process 900 as shown in FIG. 8 , the upper surface of the water-stopping material 50 is cut away so that the upper surface of the water-stopping material 50 is not positioned above the upper surface of the protruding portion 20 .
Here, the outer upper end of the water-stopping material 50 is at the same height as the upper surface of the protruding portion 20, and the water-stopping material 50 is cut to have a V-shaped cross section so that the center of the water-stopping material 50 is recessed.

According to the repair method for a transverse tooth joint configured as described above, a newly installed backup material 60 is inserted into the first gap S1 from the outside, the newly installed backup material 60 is placed on the top of the first gap S1, and the water-stopping material 50 is filled between the existing sealing material 40 from which the central portion has been removed and into the second gap S2. Therefore, even if there is no existing backup material or the existing backup material has fallen off in a transverse tooth joint 1, it is possible to repair the joint without replacing the entire joint.
This is less costly than replacing the entire transverse tooth joint 1, and is also environmentally friendly.
Furthermore, damage to road infrastructure such as bridges is minimal, and construction time is short.
In addition, since the new backup material 60 is placed in the upper part of the first gap S1, the amount of water-stopping material 50 used is small, and repairs can be made at low cost.

Second Embodiment
Next, a method for repairing a transverse tooth joint according to a second embodiment of the present invention will be described with reference to Figures 9 to 16. Note that the same parts as those in the first embodiment are given the same reference numerals.
The difference between this embodiment and the first embodiment is the material of the new backup material 60 and the new backup material arrangement process 400 (method of using the new backup material 60), but the other components are the same as those of the first embodiment.

In this embodiment, as shown in Figs. 9 and 10, a backup plate material 61 extending in the extension direction of the transverse tooth joint is used as the new backup material 60.
The backup plate 61 is made up of an acrylic plate 61a and a bottom plate 61b attached to the lower surface of the acrylic plate 61a.
The width of the acrylic plate 61a is narrower than the width of the first gap S1 and wider than the width of the second gap S2. The width of the bottom plate 61b is narrower than the width of the acrylic plate 61a.
The bottom plate 61b is attached to the acrylic plate 61a at approximately the center in the width direction.

Double-sided tape 61c is attached to the upper surface of both ends of the acrylic plate 61a in the width direction.
A string 70 is attached to the bottom plate 61b and extends upward through a hole 61e formed in the acrylic plate 61a. A plurality of strings 70 are attached to the bottom plate 61b in the longitudinal direction.
In other words, the backup plate 61 can be suspended and supported by the string 70 .

A pull-up groove 61d is formed in the acrylic plate 61a and the bottom plate 61b so as to extend in the width direction and penetrate vertically. The end of the pull-up groove 61d in the width direction is located closer to the center in the width direction than the location where the double-sided tape 61c is attached.
The width of the pull-up groove 61d is preferably set to a width that will not allow the water-stopping material 50 to drip from the pull-up groove 61d with the viscosity of the water-stopping material 50 to be filled, as described below.
A plurality of such pulling grooves 61d are arranged in the direction in which the backup plate 61 extends.

Next, a method for repairing the transverse tooth joint 1 according to this embodiment will be described.
Each step other than the new backup material arrangement step 400 is similar to the repair method according to the first embodiment.

In the new back-up material placement step 400, as shown in FIG. 11, the back-up plate 61 is inserted vertically into the first gap S1 via the second gap S2.
Then, as shown in Figures 12 and 13, the thread 70 is pulled up to attach the upper surfaces of both short side edges of the backup plate 61 to the lower surface of the existing sealing material 40 from which the central portion has been removed.

If the adhesion is insufficient just by pulling up the thread 70, as shown in Figure 14, a roughly L-shaped lifting tool K, such as a curved ruler K, is inserted from above into the lifting groove 61d and the undersides of both short side edges of the backup plate 61 are lifted up. This is done on both the left and right sides as necessary, and for each of the lifting grooves 61d where adhesion is insufficient.

Next, the rust prevention process 500 and subsequent steps are the same as those in the first embodiment.
The water-stopping material filling step 700 is as shown in FIG. 15, and the top surface cutting step 900 is as shown in FIG.

As described above, even in cases where there is no existing back-up material or the existing back-up material has fallen off, it is possible to repair the joint without replacing the entire joint, which is inexpensive and environmentally friendly.

In the first and second embodiments, the newly installed back-up material 60 is the back-up plate material 61 or the expansive body 62, but the present invention is not limited to this.
In other words, as long as it can be inserted into the first gap S1 via the second gap S2 and can be placed in the first gap S1, there is no limitation thereto.

For example, as an alternative embodiment of the expandable body 62, it may be a sponge body and a sealed bag containing the sponge body.
In this case, before use, the air is removed from the sealed bag and the bag is sealed in a substantially vacuum state to reduce the volume of the sponge body.
During construction, the expandable body 62 in a shrunk state is inserted into the first gap S1 via the second gap S2. Next, a cutter knife or the like is inserted through the second gap S2 to break the seal of the sealed bag of the expandable body 62. As a result, the sponge body inside the sealed bag returns to its original size, and the sponge body itself can be held in the upper part of the first gap S1.
Of course, it goes without saying that when the water-stopping material 50 is applied on top of the sponge body, the size, expansion rate, hardness, etc. of the sponge body are appropriately selected so that the weight of the water-stopping material 50 does not cause the sponge body (expansion body 62) to fall.
Furthermore, it is desirable to remove the sealed bag of the expansion body 62 before applying the water-stopping material 50, but this is not limited to the above.

In addition, if the backup performance is insufficient with the backup plate material 61 alone, i.e., if the water-stopping material 50 drips from the pull-up groove 61d of the backup plate material 61 in the water-stopping material filling process 700 of the second embodiment, or if it is desired to reduce the amount of water-stopping material 50 used, an auxiliary backup material may be placed on the backup plate material 61. In this case, for example, soft urethane foam can be used as the auxiliary backup material.

In addition, it is preferable to have a foreign matter removal process 100, a suction process 200, a rust prevention process 500, a primer application process 600, and an upper surface cutting process 900, but these are not essential. In addition, if the construction is possible even if the order is changed, the order may be changed as appropriate.
Moreover, although blasting is performed in the foreign matter removal step 100, the present invention is not limited to this and scraping may be used.

1 Transverse tooth joint 10 Wall portion 20 Protruding portion 20a Inner tip 40 Existing sealant 50 Water-stopping material 60 New backup material 61 Backup plate material 61a Acrylic plate 61b Bottom plate 61c Double-sided tape 61d Pulling groove 61e Hole 62 Expandable body 70 Thread 100 Foreign matter removal process 200 Suction process 300 Existing sealant removal process 400 New backup material placement process 500 Rust prevention process 600 Primer application process 700 Water-stopping material filling process 800 Hardening process 900 Upper surface cutting process K Pulling fitting (curved ruler)
S1 First gap S2 Second gap

Claims (3)

A method for repairing a transverse tooth type joint having wall portions extending substantially vertically opposed to each other and spaced apart to form a first gap, and protruding portions protruding from upper ends of the wall portions opposed to each other and spaced apart to form a second gap, the first gap being provided with an existing seal material, and no existing back-up material being present below the existing seal material or the existing back-up material has fallen off, comprising:
an existing sealant removing step of inserting a blade through the second gap to cut a central portion of the existing sealant into a width substantially equal to the width of the second gap and removing the cut central portion of the existing sealant;
a new back-up material placement step of inserting a new back-up material into the first gap from the outside and placing the new back-up material on an upper part of the first gap;
a water-stopping material filling step of filling a water-stopping material between the existing sealant portions from which the central portions have been removed and into the second gap;
and a hardening step of hardening the filled water-stopping material. The repair method for a transverse tooth joint according to claim 1, characterized in that in the new backup material placement process, the new backup material is an expandable body, and the expandable body is inserted into the first gap through the second gap and expanded to support it at the top of the first gap. The repair method for a transverse tooth joint according to claim 1, characterized in that in the step of placing the new backup material, the new backup material is a plate material, and the plate material is inserted into the first gap through the second gap, and the upper surfaces of both short-side edge portions of the plate material are attached to the lower surface of the existing seal material from which the center portion has been removed.