JP7496964B2 - Structure for improving durability of reinforced concrete structures and method for improving durability of reinforced concrete structures - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act. Presented at the 2018 Tohoku Branch Technical Research Presentation of the Japan Society of Civil Engineers on March 2, 2019.

The present invention relates to a structure for improving the durability of reinforced concrete structures, such as reinforced concrete wall parapets, and a method for improving the durability of reinforced concrete structures.

Generally, one of the causes of deterioration of reinforced concrete structures is known to be salt damage, in which the presence of chloride ions causes rebar corrosion. One method for suppressing salt damage to reinforced concrete structures is to sprinkle a surface modifier on the surface of the reinforced concrete structure during surface finishing work, and disperse the surface modifier on the surface of the reinforced concrete structure while performing surface finishing work with a trowel, thereby imparting resistance to chloride ion penetration to the reinforced concrete structure (see, for example, Patent Document 1).

JP 2018-16510 A

In the case of the surface quality improvement method of Patent Document 1, the application range is limited to the surface of the reinforced concrete structure, so it is thought that it is possible to prevent chloride ions from penetrating from the wall surface. However, if the reinforced concrete structure has floors and walls, there is a risk that chlorides accumulated on the floor will penetrate into the interior through the horizontal joints between the floor and the wall, and the chloride ions at that time will penetrate widely into the concrete that makes up the wall. If this happens, salt damage will occur in the reinforced concrete structure, leading to deterioration of the reinforced concrete structure.

The present invention was made in consideration of these points, and its purpose is to suppress salt damage to reinforced concrete structures that have floors and walls, thereby extending the lifespan of the reinforced concrete structures.

To achieve the above objective, the present invention provides a recess formed in the wall surface with a rubber-based elastic body to suppress the penetration of ionized substances.

The first invention is a method for improving the durability of a reinforced concrete structure having a floor and a wall, characterized by comprising a recess forming step for forming a recess in the wall covering portion, the recess opening in the wall surface and extending in a direction along the floor, and a rubber-based elastic body installation step for providing a rubber-based elastic body in the recess formed in the recess forming step.

According to this configuration, a recess is formed in the cover portion of the wall and a rubber-based elastic body is provided in this recess, which prevents chlorides that have accumulated on the floor, for example, from penetrating toward the upper side of the wall. Furthermore, by providing a rubber-based elastic body in the recess, the recess is blocked by the rubber-based elastic body. This reduces the amount of chlorides that come into contact with the recess, making it even more difficult for chlorides to penetrate the wall. The chlorides that accumulate on the floor are, for example, antifreeze agents and salt that has drifted in from the sea.

The recess formation process can be carried out on walls after the concrete has hardened. The recess can also be formed by placing a recess-forming member for forming a recess in a formwork before the concrete is poured, pouring the concrete into the formwork, and removing the recess-forming member after the concrete has hardened.

The second invention is characterized in that a foamed rubber-based elastic body is used in the rubber-based elastic body installation process.

This allows the rubber-based elastic body to be easily deformed and inserted into the recess, improving workability.

The third invention is characterized in that the rubber-based elastomer installation process uses a rubber-based elastomer that has an amorphous nature when installed in the recess and changes to a fixed structure due to humidity or a curing agent.

This allows the rubber-based elastomer to be placed in the recess while still in an amorphous state, and then by changing the structure to a fixed shape, the rubber-based elastomer will not move out of the recess, and can be securely held within the recess.

The fourth invention is characterized in that in the rubber-based elastic body installation process, a rubber-based paint is applied to the inner surface of the recess formed in the recess formation process.

With this configuration, the rubber-based paint is applied to the inner surface of the recess, so that the inner surface of the recess is coated with the rubber-based paint, further enhancing the effect of suppressing the penetration of chlorides.

The fifth invention is characterized in that after the rubber-based paint is applied, the coating film of the rubber-based paint and the rubber-based elastomer are adhered to each other by a self-adhesive rubber having self-adhesive properties.

With this configuration, the rubber-based paint coating applied to the inner surface of the recess and the rubber-based elastomer can be integrated together by the adhesiveness of the self-adhesive rubber.

The sixth invention is characterized in that after the rubber-based paint is applied, a laminate in which a self-adhesive rubber layer having self-adhesive properties and the rubber-based elastomer are laminated in advance by adhesive force is provided in the recess.

The seventh invention is characterized in that in the recess forming process, the recess is formed near the deck of the concrete wall parapet of the bridge.

That is, in areas where snowfall and freezing are likely, antifreeze agents can accumulate on bridge decks. As this antifreeze agent is a chloride, it can easily cause salt damage. In this invention, a rubber-based paint is applied to the recesses formed near the deck of the balustrade of a bridge, which is prone to salt damage, so that the infiltration of saltwater from the deck to the balustrade is blocked, and the effect of suppressing salt damage becomes even more pronounced.

The eighth invention is a durability improvement structure for a reinforced concrete structure having a floor and a wall, characterized in that a rubber-based elastic body is provided in a recess formed in the covering portion of the wall, opening into the wall surface and extending in a direction along the floor.

According to the present invention, by forming a recess in the covering portion of the wall and providing a rubber-based elastic body in this recess, for example, if chlorides accumulate on the floor, the chlorides are less likely to permeate toward the upper side of the wall, and salt damage to reinforced concrete structures can be suppressed. This makes it possible to suppress deterioration of reinforced concrete structures and extend their lifespan.

FIG. 1 is a longitudinal cross-sectional view of a reinforced concrete structure. FIG. 2 is a diagram showing a portion of a reinforced concrete structure as viewed from the direction opposite the wall surface. 11 is a partial cross-sectional view of the vicinity of a lower part of a wall, illustrating a recess forming step. FIG. FIG. 4 is a view equivalent to FIG. 3 and explains a coating step. FIG. 4 is a view equivalent to FIG. 3 for explaining the self-adhesive rubber installation process. FIG. 4 is a view equivalent to FIG. 3 and explains a rubber-based elastic body installation step. FIG. 7 is a view corresponding to FIG. 6 according to a modified example of the embodiment. FIG. 2 is a cross-sectional view illustrating test specimens of Example 1, Comparative Example 1, and Comparative Example 2. 1 is a graph showing the results of chloride amount measurement in Example 1, Comparative Example 1, and Comparative Example 2. 1 is a graph showing the results of chloride amount measurement in Examples 2 and 3 and Comparative Examples 3 to 6. Photographs showing the state of test specimens of Examples 2 and 3 and Comparative Example 4 after testing.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that the following description of the preferred embodiment is essentially merely an example and is not intended to limit the present invention, its applications, or its uses.

Figure 1 shows a reinforced concrete structure 1 according to an embodiment of the present invention. The reinforced concrete structure 1 is a bridge (road bridge) made of reinforced concrete, and includes a deck 2, which corresponds to a floor, and a parapet 3, which corresponds to a wall. The deck 2 extends approximately horizontally. An antifreeze agent is sprayed onto the upper surface 2a of the deck 2, mainly in winter, which can cause chlorides to accumulate on the upper surface 2a. The parapet 3 is a so-called RC parapet, and extends approximately vertically upward from near the upper surface 2a of the deck 2. Reference symbol 3a indicates the wall surface of the parapet 3.

Reinforcing bars 4 extending vertically and reinforcing bars 5 extending horizontally are embedded in the reinforced concrete structure 1. Reinforcing bars 4 extend from inside the wall parapet 3 until they reach inside the deck 2. Reinforcing bars 5 extend approximately horizontally from the lower end of reinforcing bars 4 inside the deck 2. Reinforcing bars 6 are embedded inside the wall parapet 3, and reinforcing bars 7 are embedded in the deck 2. A joint 8 is provided between the lower end of the wall parapet 3 and the upper surface 2a of the deck 2.

(Structure for improving durability of reinforced concrete structures)
The reinforced concrete structure 1 is provided with a durability-improved structure A. As shown in Fig. 6, the durability-improved structure A is constructed by applying a rubber-based paint to the inner surface of a recess 3b formed in the cover portion of the wall balustrade 3, opening on the wall surface 3a and extending in a direction along the deck 2. The rubber-based paint has fluidity before application, but loses fluidity and changes to a fixed structure after a certain time has passed after application. Such a rubber-based paint changes to a fixed structure due to the humidity in the atmosphere or a hardener contained in the paint. In other words, the durability-improved structure A is a structure in which a rubber-based elastic body is provided in the recess 3b by applying a rubber-based paint to the inner surface of the recess 3b.

The above-mentioned cover portion is the concrete portion that covers the reinforcing bars 6 in the wall balustrade 3, and the thickness of this cover portion, i.e., the cover thickness, can be expressed as the dimension in the wall thickness direction from the reinforcing bars 6 closest to the wall surface 3a in the wall balustrade 3 to said wall surface 3a. Examples of rubber-based paints include primers and liquid rubber materials.

The recess 3b is formed near the deck 2 of the balustrade 3. Specifically, the recess 3b is arranged at a distance of 0 mm to 35 mm from the upper surface 2a of the deck 2. The depth dimension of the recess 3b is set shorter than the cover thickness dimension, so that the bottom surface of the recess 3b does not reach the reinforcing bars 6. In other words, in this embodiment, the formation of the recess 3b does not expose the reinforcing bars 6 of the balustrade 3. The depth of the recess 3b can be set to, for example, 5 mm or more, or can also be set to 10 mm or more. The upper limit of the depth of the recess 3b can be set by the cover thickness of the balustrade 3 as described above, and can be set to less than the cover thickness, for example, 20 mm or less or 10 mm or less.

The width (vertical dimension) of the recess 3b can be set to, for example, 10 mm or more or 20 mm or more. The upper limit of the width of the recess 3b can be set to, for example, 20 mm or less or 40 mm or less.

The recess 3b can be formed so as to extend in a direction along the top surface 2a of the deck 2, i.e., approximately horizontally in the extension direction of the road. The recess 3b can be formed by scraping the wall surface 3a of the existing wall balustrade 3. The tools and devices used in this process are conventionally known. The recess 3b can also be called a groove, as it extends in the extension direction of the road. Although not shown, the recess 3b can also be formed by placing a recess forming member for forming the recess 3b in the formwork before pouring the concrete, pouring the concrete into the formwork, and removing the recess forming member after the concrete has hardened.

The above-mentioned rubber-based paint may be of any type as long as it has adhesion to concrete. By applying the rubber-based paint to the inner surface of the recess 3b, the coating film 10 shown in FIG. 4 is formed. This coating film 10 is part of the durability improvement structure A and becomes a rubber-based elastic body.

As shown in FIG. 5, after the rubber-based paint has been applied, self-adhesive rubber 11 having self-adhesive properties can be inserted into the bottom side of the recess 3b. The self-adhesive rubber 11 can be a viscoelastic material, such as butyl rubber. In this embodiment, the self-adhesive rubber 11 is a joint material made of butyl rubber. By inserting the self-adhesive rubber 11 into the recess 3b, the self-adhesive rubber 11 adheres to the coating film 10, and the self-adhesive rubber 11 is prevented from falling off. The self-adhesive rubber 11 is part of the durability improvement structure A.

As shown in FIG. 6, a rubber-based elastic body 12 can be placed in the recess 3b so that it is layered on the self-adhesive rubber 11. The rubber-based elastic body 12 can be made of an elastic body made of various rubbers. The rubber-based elastic body 12 adheres to the self-adhesive rubber 11, and is therefore held to the coating film 10 by the self-adhesive rubber 11. In other words, the self-adhesive rubber 11, which has self-adhesive properties, can adhere the coating film 10 of the rubber-based paint to the rubber-based elastic body 12. The rubber-based elastic body 12 is part of the durability improvement structure A.

In this embodiment, an example in which the durability-improving structure A includes the coating film 10, the self-adhesive rubber 11, and the rubber-based elastomer 12 has been described, but this is not limiting, and both the self-adhesive rubber 11 and the rubber-based elastomer 12 may be omitted. In this case, the structure in which the coating film 10 is formed on the inner surface of the recess 3b becomes the durability-improving structure A. The durability-improving structure A may also be composed of the coating film 10 and the self-adhesive rubber 11, or the durability-improving structure A may also be composed of the coating film 10 and the rubber-based elastomer 12. Furthermore, the rubber-based elastomer 12 may be provided in close contact with the inner surface of the recess 3b, in which case the coating film 10 and the self-adhesive rubber 11 can be omitted. As the rubber-based material, one that adheres to or adheres to the inner surface of the recess 3b is preferable.

(Method of improving durability of reinforced concrete structures)
Next, a method for improving the durability of a reinforced concrete structure will be described. First, as shown in Fig. 3, a recess 3b is formed in the covering portion of the wall balustrade 3, opening on the wall surface 3a and extending in a direction along the deck 2. This process is the recess forming process. The cross section of the recess 3b formed in the recess forming process may be rectangular, V-shaped, or U-shaped. The recess 3b can be formed using a known machine.

As shown in FIG. 4, a rubber-based paint is then applied to the inner surface of the recess 3b formed in the recess formation process. This is the application process. The rubber-based paint can be applied using a brush or roller, or can be applied by spraying the paint with a sprayer. It is preferable to apply the paint to the entire inner surface of the recess 3b, but it is not necessary to apply the paint to some parts. As a result, a coating film 10 made of a rubber-based elastomer is formed, and this process corresponds to a rubber-based elastomer installation process in which a rubber-based elastomer is installed in the recess 3b. In the rubber-based elastomer installation process, a paint that has an amorphous nature when installed in the recess 3b and changes to a fixed structure due to humidity or a hardener can be used.

Next, as shown in FIG. 5, after the application process, the self-adhesive rubber 11 having self-adhesive properties is inserted into the recess 3b. This is the self-adhesive rubber installation process. Specifically, a butyl rubber-based joint material serving as the self-adhesive rubber 11 is pushed into the recess 3b, thereby adhering the self-adhesive rubber 11 to the coating film 10. The self-adhesive rubber 11 may be formed into a plate shape or a rod shape. The self-adhesive rubber 11 may be adhered so as to cover the entire coating film 10, or may be adhered so as to cover only a portion of the coating film 10.

Then, as shown in FIG. 6, the rubber-based elastic body 12 is inserted into the recess 3b. This process can also be called the rubber-based elastic body installation process. The rubber-based elastic body 12 can be pushed into the recess 3b while being elastically deformed. By adhering the rubber-based elastic body 12 to the self-adhesive rubber 11, it is possible to prevent the rubber-based elastic body 12 from falling off from the recess 3b. The rubber-based elastic body 12 may be molded into a plate shape or a rod shape. The rubber-based elastic body 12 may be adhered to the self-adhesive rubber 11 so that the rubber-based elastic body 12 covers the entire self-adhesive rubber 11, or the rubber-based elastic body 12 may be adhered to the self-adhesive rubber 11 so that the rubber-based elastic body 12 covers only a part of the self-adhesive rubber 11. The rubber-based elastic body 12 may be a rubber-based elastic body with a foam structure or a rubber-based elastic body with a non-foam structure.

The self-adhesive rubber 11 may be filled into the recess 3b in the self-adhesive rubber installation process, in which case it becomes the self-adhesive rubber filling process. When filling the self-adhesive rubber 11 into the recess 3b, the rubber-based elastomer 12 may be provided so as to cover the surface of the self-adhesive rubber 11. Also, the self-adhesive rubber installation process may be omitted and the rubber-based elastomer installation process may be performed, and the rubber-based elastomer 12 may be filled into the recess 3b in the rubber-based elastomer installation process. In this case it becomes the rubber-based elastomer filling process.

Figure 7 is a diagram illustrating the rubber-based elastomer installation process according to a modified embodiment of the present invention. In this modified example, after the application of the rubber-based paint, a self-adhesive rubber layer made of self-adhesive rubber 11 having self-adhesive properties and a rubber-based elastomer 12 are laminated in advance by adhesive force to form a laminate 13 in the recess 3b. The process is the same as the above example up to the application process. In this modified example, a laminate 13 in which the self-adhesive rubber 11 and the rubber-based elastomer 12 are laminated is prepared in advance. After the application process is completed, the laminate 13 is inserted into the recess 3b. In this modified example, the application process may be omitted, and a rubber-based elastomer installation process in which the laminate 13 is inserted into the recess 3b may be performed.

(Chloride uptake test)
Next, a chloride uptake test by the wall parapet 3 will be described.

(Test 1)
In the test 1, as shown in FIG. 8, a specimen of Example 1, a specimen of Comparative Example 1, and a specimen of Comparative Example 2 were prepared. These specimens were assumed to have the above-mentioned deck 2 and balustrade 3. The dimensions of the specimens were: deck 2 thickness T1 100 mm, deck 2 length L 400 mm, balustrade 3 thickness T2 100 mm, and balustrade 3 height H 400 mm. The concrete constituting the deck 2 and balustrade 3 was made from a ready-mixed concrete factory (30-18-20-N), and balustrade 3 was cast three days after deck 2 was cast. The specimens were demolded the next day and then standard underwater cured for one month. The vertical surfaces on the left and right sides of the specimen were coated with silicone to prevent the movement of water, and a pool 20 for storing salt water was made with silicone on the upper surface 2a of the deck 2.

The specimen of Example 1 has the durability improvement structure A described above (shown enlarged in FIG. 6). The recess 3a was formed 35 mm above the bottom surface of the pool 20. The width and depth of the recess 3b were each 10 mm. A primer made of a rubber-based paint was applied to the inner surface of the recess 3a, and then the self-adhesive rubber 11 and the rubber-based elastic body 12 were inserted into the recess 3b.

The specimen of Comparative Example 1 does not have the durability improvement structure A. The specimen of Comparative Example 2 has a coating layer 30 formed by continuously applying primer and epoxy resin to the wall surface 3a of the wall balustrade 3 from the bottom surface of the pool 20 up to a distance of 50 mm. The specimens of Comparative Example 1 and Comparative Example 2 do not have recesses formed in the wall surface, and the wall surface is composed of a flat surface.

The chloride wicking test conditions are as follows. The specimen was placed in a high-temperature room (30.0-33.1°C, humidity 54-60%). The water level in the pool 20 was kept at 10 mm for a period of 140 days. After the test was completed, powder was collected by drilling from heights of 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, and 350 mm from the bottom of the pool 20 of the specimen, at 10 mm intervals in the depth direction (thickness direction of the wall balustrade 3) to a maximum depth of 50 mm. The chloride ion concentration of each collected powder was measured using an X-ray fluorescence analyzer.

As for appearance, 34 days after the start of the test, the wall surface 3a of Comparative Example 1 showed uneven coloring due to chloride absorption, and crystals had grown in the height direction as the chloride was repeatedly absorbed and dried to crystallize. Chloride crystals had also formed on the surface of the epoxy resin on the wall surface 3a of Comparative Example 2. On the wall surface 3a of the Example, almost no chloride absorption was observed.

Figure 9 is a graph showing the chloride ion concentration of each test specimen of Comparative Example 1, Comparative Example 2, and Example 1. The horizontal axis of each graph shows the chloride ion concentration, and the vertical axis shows the measurement position (mm), i.e., the height from the bottom of the pool 20. The chloride ion concentration at each height of 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, and 350 mm can be seen. Also, the circle in the legend indicates the chloride ion concentration from the first layer, i.e., the wall surface 3a of the wall balustrade 3, to a depth of 10 mm from the reference point. The upward triangle in the legend indicates the chloride ion concentration from the second layer, i.e., the wall surface 3a of the wall balustrade 3, to a depth of 10 mm to 20 mm. The diamond in the legend indicates the chloride ion concentration from the third layer, i.e., the wall surface 3a of the wall balustrade 3, to a depth of 20 mm to 30 mm. The square marks in the legend indicate the chloride ion concentration in the fourth layer, that is, up to a depth of 30 mm to 40 mm based on the wall surface 3a of the wall balustrade 3. The downward triangle marks in the legend indicate the chloride ion concentration in the fifth layer, that is, up to a depth of 40 mm to 50 mm based on the wall surface 3a of the wall balustrade 3.

As is clear from Figure 9, in Comparative Example 1, the chloride ion concentration is high in all layers in the height range of 50 mm to 150 mm. In particular, the chloride ion concentration at the first layer at a height of 100 mm is extremely high, which may cause salt damage.

In addition, in Comparative Example 2, the chloride ion concentration tends to be lower overall than in Comparative Example 1, but as in Comparative Example 1, the chloride ion concentration at a height of 100 mm in the first layer is extremely high, which may cause salt damage.

On the other hand, in the case of Example 1, the chloride ion concentration at all measurement points is significantly lower than that of Comparative Examples 1 and 2. In the second to fifth layers, the chloride ion concentration is close to zero, and also in the first layer, at heights of 100 mm or more, the chloride ion concentration is close to zero. Therefore, the chloride is prevented from penetrating upward into the wall parapet 3 and inward in the thickness direction.

(Test 2)
Next, the test 2 will be described with reference to Figs. 10 and 11. In the test 2, specimens of Examples 2 and 3 and specimens of Comparative Examples 3 to 6 were prepared. The dimensions of each specimen are the same as those of the specimens used in the test 1. The specimen of Example 2 has a durability improvement structure A, and a foamed rubber-based elastic body 12 is placed in the recess 3b. The specimen of Example 3 has a durability improvement structure A, and a rubber-based elastic body formed into a fixed structure by applying a liquid rubber material to the inner surface of the recess 3b. The specimen of Comparative Example 3 does not have the durability improvement structure A, and is an example in which a member made of a hard material (hard resin) is placed in the recess 3b. The specimen of Comparative Example 4 does not have the durability improvement structure A, and is an example of no countermeasure in which no recess is formed and no rubber or the like is placed. The specimen of Comparative Example 5 does not have the durability improvement structure A, and is an example in which a recess 3b is formed but nothing is placed in the recess 3b. The width and depth of the recess 3b of Comparative Example 5 are 10 mm. The specimen of Comparative Example 6 does not have durability improvement structure A, and like Comparative Example 5, is an example in which nothing is installed in the recess 3b, but the width and depth of the recess 3b in Comparative Example 6 are each 20 mm.

The test method and conditions for Test 2 were the same as those for Test 1 above. Figure 10 is a graph showing the chloride ion concentration of each specimen for Examples 2 and 3 and Comparative Examples 3 to 6. The vertical and horizontal axes are the same as those in the graph shown in Figure 9, but the measurement results for the chloride ion concentration are shown for the first layer, i.e., wall surface 3a of the wall balustrade 3, up to a depth of 10 mm from the base.

It can be seen that in Comparative Examples 3 to 6, the amount of chloride ions at a measurement height of 50 mm exceeds 30 kg/ ^m3 , but in Examples 2 and 3, it is significantly below 10 kg/ ^m3 . Therefore, according to Examples 2 and 3, the permeation of chlorides toward the upper side of the wall parapet 3 and inward in the thickness direction is suppressed.

Figure 11 is a photograph showing the condition of the specimens of Examples 2 and 3 and Comparative Example 4 after testing, taken from the bottom to the middle of the wall surface 3a of the wall balustrade 3 in the vertical direction. The white foam-like objects are chloride crystals.

In the case of Comparative Example 4 (no countermeasure), the amount of chloride ions at a measurement height of 50 mm is close to 40 kg/ ^m3 , as shown in Figure 10. In this Comparative Example 4, as shown in Figure 11, chlorides are present as crystallized over a wide area on the surface of the test specimen, and the crystals grow significantly in the height direction. On the other hand, in Examples 2 and 3, the area of chloride crystallization is significantly narrower than in Comparative Example 4. This is because the chlorides are suppressed from penetrating upward into the wall parapet 3 and inward in the thickness direction.

(Effects of the embodiment)
As described above, according to this embodiment, the inner surface of the recess 3b formed in the covering portion of the wall balustrade 3 can be coated with a rubber-based paint, so that when chlorides accumulate on the deck slab 2, the chlorides are less likely to permeate toward the upper side of the wall balustrade 3, thereby suppressing salt damage to the reinforced concrete structure 1. This makes it possible to suppress deterioration of the reinforced concrete structure 1 and extend the life of the reinforced concrete structure 1.

In addition, by inserting self-adhesive rubber 11 into the recess 3b, the self-adhesive rubber 11 adheres to the coating film 10 of the rubber-based paint, and the recess 3b is blocked by the self-adhesive rubber 11. This reduces the amount of chloride that comes into contact with the recess 3b, making it even more difficult for chloride to penetrate into the wall balustrade 3.

In addition, by inserting a rubber-based elastic body 11 into the recess 3b, the recess 3b is blocked by the rubber-based elastic body 11. This reduces the amount of chloride that comes into contact with the recess 3b, making it even more difficult for chloride to penetrate into the wall balustrade 3.

The above-described embodiments are merely illustrative in all respects and should not be interpreted as limiting. Furthermore, all modifications and variations within the scope of the claims are within the scope of the present invention.

In the above embodiment, the reinforced concrete structure 1 is a bridge made of reinforced concrete, but the present invention is not limited to this and can be applied to various types of reinforced concrete structures.

As explained above, the present invention can be applied to, for example, the wall parapets of reinforced concrete bridges.

Reference Signs List 1 Reinforced concrete structure 2 Deck 2a Top surface 3 Wall balustrade 3a Wall surface 3b Recess 10 Coating film 11 Self-adhesive rubber 12 Rubber-based elastic body

Claims (2)

A method for improving the durability of a reinforced concrete structure having a floor and a wall, comprising the steps of:
a recess forming step of forming a recess in a covering portion of the wall, the recess opening in the wall surface and extending in a direction along the floor;
a rubber-based elastomer installation process for applying a rubber-based paint to the inner surface of the recess formed in the recess forming process, and after applying the rubber-based paint, inserting a laminate in which a self-adhesive rubber layer having self-adhesive properties and a foamed rubber-based elastomer are pre-laminated by their adhesive force into the recess, and adhering the laminate to the coating of the rubber-based paint by the adhesive force of the self- adhesive rubber layer. The method for improving durability of a reinforced concrete structure according to claim 1 ,
A method for improving durability of a reinforced concrete structure, wherein the recess forming step forms the recess in the vicinity of the deck of a concrete wall parapet of a bridge.

Images