JP3128166B2 - Pedestrian bridge repair method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repair method and a repair structure capable of performing safe workable bonding and sealing with good workability in repairing and repairing a pedestrian bridge.

[0002]

2. Description of the Related Art The first pedestrian bridge, which is now ubiquitous in Japan, was installed on the old national highway No. 22 in Aichi Prefecture in 1959. After that, it was dramatically improved throughout the country in the early 1965's, and has reached the present day. However, recently, it has become a problem to secure the durability and safety of the pedestrian bridge in response to changes in traffic conditions. On the other hand, growing interest in the aesthetic appearance of civil engineering structures in cities is also an important factor, and when renovating and repairing pedestrian bridges, the surface finish of the bridge surface (pedestrian surface) has been traditionally used. There has been a growing demand for using tiles or stones having aesthetics in place of the asphalt blocks used.

[0003] Originally, pedestrian bridges installed in places with heavy traffic are often exposed to severe outdoor conditions as structures, including vibrations, and in particular, stone materials and tiles are bonded to the bridge surface. In this case, the selection of the adhesive and the selection of the joint material at the joint are one of the important factors that affect stone materials, tile cracks, etc., including durability of the pedestrian bridge.

As shown in FIG. 3, the existing pedestrian bridge bridge surface W is
It usually has a four-layer structure including a base material (steel material, concrete, etc.) 14, a mortar layer 16 for adjusting the foundation, a cement adhesive 12, and a surface finishing material 10 such as asphalt concrete or a block. Renovation work using actual pedestrian bridge tiles or stones 10a
It is usual to carry out the picking out of the layers up to the base adjustment mortar 16. Then, after adjusting the unevenness with a mortar, it becomes the process of sticking and attaching a surface finishing material such as a tile or a stone.

[0005] The step of attaching the surface finishing material includes the steps of applying a cement-based adhesive 12 and a surface finishing material 10a such as a tile.
And filling of the joint 17 with the cement joint material 15 and curing of the cement adhesive 12 and the joint material 15 (FIG. 4). In this step, in the case of the cement-based adhesive 12 which has been conventionally used for bonding the surface finishing material 10a such as a stone or a tile, the bonding is performed in consideration of the splicing property with the base, the waterproof effect, the bonding reliability, and the like. 5 layers
It is necessary to take about 10 to 10 mm, and it is necessary to take a sufficient curing period due to the hydration reaction mechanism of the cement paste. In addition, cracks easily occur in the cement-based adhesive layer 12 and the joint material 15 due to vehicle traffic or vibrations caused by an earthquake, and water leaks from the cracks, which causes deterioration of the pedestrian bridge body.

[0006]

As described above, the cement-based adhesive which has been conventionally used does not sufficiently follow the vibration of the pedestrian bridge.
There is a problem that a skilled craftsman is required, and the curing time of the adhesive after the completion of the construction needs to be considerably long.

Further, even if a hard epoxy resin adhesive which has been conventionally used for bonding ordinary tiles is simply diverted to bonding tiles and the like on a pedestrian bridge, the ability to follow the vibration of the pedestrian bridge is not sufficient. , Not suitable for use.

The present invention has been made in view of the above problems, and enables repair and renovation of a pedestrian bridge bridge surface capable of withstanding severe conditions outdoors centering on vibration, and greatly shortens the construction period. It is an object of the present invention to provide a pedestrian bridge bridge surface repair method and a repair structure that can be used.

[0009]

Means for Solving the Problems To solve the above problems, a method for repairing a pedestrian bridge bridge surface according to the present invention comprises a base material layer, a cement mortar layer for adjusting a foundation, a cement adhesive layer, and a surface finishing material. In repairing the pedestrian bridge, the surface finishing material and cement adhesive are removed,
The surface of the cement mortar layer for adjusting the ground is made uneven, then an elastic adhesive is applied to the surface of the cement mortar layer for adjusting the ground, and a surface finishing material such as a tile is attached.

[0010] In some cases, the surface of the base material layer is adjusted unevenly, and then an elastic adhesive is applied to the surface of the base material layer, and a surface finishing material such as a tile is applied. It can be attached.

It is preferable to fill the joints between the surface finishing materials with a joint material, and particularly to fill an elastic joint material. It is preferable to set the viscosity of the elastic joint material in the range of 300 to 5,000 P, the index for evaluating thixotropic properties in the range of 3.0 to 5.0, and the hardness of 60 to 80 (Shore A).

The pedestrian bridge bridge surface repair structure of the present invention comprises a base material layer, an underlay adjustment cement mortar layer, an elastic adhesive layer, and a surface finishing material, and has a structure repaired by the above repair method.

The coating thickness of the elastic adhesive is 0.5 to 2 m.
m is preferable, and about 1 mm is sufficient. In the case of the present invention, the use of an elastic adhesive allows the adhesive layer to have a thickness of 0.1 mm.
When the thickness is about 5 to 2 mm, preferably about 1 mm, a sufficient waterproof effect can be obtained together with a sufficient adhesive effect and vibration followability. Furthermore, the curing period can be set to be able to walk in about one day, which contributes to a reduction in the total weight of the structure.

In the joint filling step, similarly to the bonding step, when a conventional cement-based adhesive is used as a joint material, cracking tends to occur due to poor followability to vibration, and the training period is long.

On the other hand, in the case of the present invention, by using an elastic joint material as a joint material, it is possible to obtain a bridge surface excellent in followability to vibration and waterproofness, and there is an advantage that a training period can be reduced.

The kind of the elastic adhesive used for bonding in the present invention includes a flexible epoxy resin type, urethane resin type, silicone resin type, modified silicone resin type, polysulfide resin type, acrylic resin type, SBR type and the like. Can be mentioned. Examples of the form include a combination of a primer and a non-primer, a one-pack or two-pack solventless system, an aqueous system, and the like.

Of these, the combined use of a primer containing a large amount of an organic solvent and an aqueous type having poor water resistance are disadvantageous.
Silicone-based products are not suitable for repairing pedestrian bridges in terms of cost, and flexible epoxy-based materials whose physical properties change over time are not suitable.

The most suitable elastic adhesive for carrying out the present invention includes a solventless modified silicone resin which does not require a primer.

The elastic joint material used as the joint material in the present invention may be a flexible epoxy resin, a urethane resin, a silicone resin, a modified silicone resin, a polysulfide resin, an acrylic Resin-based, SBR-based, and the like.

As for the form of the adhesive, as in the case of the elastic adhesive, the form using a primer in combination or the form using a non-primer, and the form of a one-pack or two-pack solventless system or water system can be considered.

However, a combination of a primer containing a large amount of an organic solvent, a water-based material which is thin and tends to have poor water resistance, a silicone-based material which is not cost-effective, and a material whose physical properties change with time may be used. A flexible epoxy or the like cannot be said to be appropriate as in the case of an adhesive, and a solventless modified silicone system that does not require a primer is most desirable.

Another important point regarding the selection of the joint material is that its performance is elastic and has a performance different from that of a general high-conforming elastic sealing material for construction. It must be.

The difference between the building sealing material and the joint material used for the pedestrian bridge will be described below. The difference between the joint material for pedestrian bridges and the sealing material for construction is that the hardness is considerably different even though they are the same elastic body. That is, building sealing materials generally have an elongation of more than 200%, but floor joints for civil engineering use have an elongation of about 100% and have a sufficient portion, especially tiles and stone materials for pedestrian bridges. Joints for applications such as
% Is considered sufficient, and differs in elongation from normal building sealants.

On the contrary, it is important that the bridge surface of the pedestrian bridge should have hardness enough to withstand the damage caused by the heels of the high heels for women and the damage caused by the tip of the umbrella.

In this regard, the danger can be reduced by reducing the design of the joint width, but new performance is required for the joint material design by setting the joint width to be small. become. That is,
It is necessary to consider the balance between the viscosity and flowability that can be filled in a small joint width and the sagging resistance for a constant gradient.

The following problems are involved in the joint filling work on the pedestrian bridge. That is, regarding the properties of the joint material, when filling the joint material with a caulking gun, low viscosity and thixotropy have good workability, and the joint size is small and deep joint (for example, joint width 5 mm, depth 20 mm). In this case, a material having a low viscosity is similarly required, but it is convenient to fill the joints easily without having thixotropic.

In addition, the shape of the pedestrian bridge bridge surface is often inclined slightly toward the outside of the bridge surface in order to guide rainwater or the like to the water channel provided at the end of the bridge surface, so that the joint material has a low viscosity. If it is too small or the thixotropy is too small, the joint material will flow out, making it impossible to construct joints along the bridge surface. That is, regarding the properties of the joint material on the pedestrian bridge, there is a problem in adjusting the viscosity and thixotropic properties.

The joint material in the present invention has a viscosity of 3
00 to 5,000P, an index for evaluating thixotropicity (value obtained by dividing the viscosity at 20 rotations of the rotor in the B-type viscometer by the viscosity at 2 rotations) in the range of 3.0 to 5.0. Is preferably used, and good bridge joint filling is possible.

For example, for a joint having a width of 5 mm and a depth of 20 mm, a joint material having a viscosity of about 400 P and a thixotropic index of about 4.5 is most preferably used.

Regarding the performance of the joint material, it is necessary to be able to withstand not only adhesiveness to an adherend, water tightness and conformability but also human damage.

In the present invention, the tensile strength (JIS
K6301 No. 1 dumbbell) 30-40 kgf / c
m ² , elongation at break 80-120%, tensile adhesion (JIS A 5758) 15-30 kgf / cm
² It is preferable to use an elastic joint material having an elongation at break of 20 to 50% and a hardness (Shore A) of 60 to 80, which can withstand water tightness and human damage. You can get a pedestrian bridge.

In addition, as the elastic joint material, it is necessary to adjust the curing speed and the viscosity at the work site in order to efficiently perform the work at the work site.

[0033]

The present invention will be described in more detail with reference to the following examples. 2 in renovation work of pedestrian bridge
An example using a liquid-type modified silicone-based elastic adhesive and a joint material will be described.

PM200 (manufactured by Cemedine Co., Ltd.) was used as a two-part modified silicone-based elastic adhesive. At the time of construction, a spreadable material having a pot life of about 2 hours and a viscosity at 20 ° C. of about 3000P was used.

As a process, a surface finishing material 1 such as an asphalt block of an existing pedestrian bridge bridge surface W as shown in FIG.
The cement mortar layer 16 on the base concrete 14 is exposed by removing the cement adhesive 12 and the cement-based adhesive 12, and the surface thereof is unevenly adjusted with a keren (by a grinder or the like). (Figure 1) about 1mm
Was applied.

Next, the surface finishing material 10a such as a tile was attached and the bonding step was completed. After about 3 hours, the adhesive layer 18 began to develop strength, and after about 1 day, an adhesive layer having good follow-up properties with respect to cracks on the underlayer also serving as a waterproof coating was obtained.

The step of filling the joint material 20 into the joint material 22 includes:
It can be carried out immediately after the bonding step is completed. However, if the bonding step and the joint filling company are different, there may be a slight time difference, but there is no problem in that point.

As the joint material to be used, a filler and a plasticizer were added to a known two-pack type modified silicone-based elastic sealing material to adjust the physical properties and workability of the joint material.

The properties of the main agent and the curing agent are such that the weight ratio is 1: 1 and the viscosity of the mixture is about 4,500 P at 20 ° C. Filling was able to be performed on joints of about 10 to 10 mm.
Further, an epoxy-based reactive diluent, a plasticizer, an organic solvent or the like may be added as a viscosity adjuster with an upper limit of 5% in order to cope with the on-site work temperature.

As for the performance, hardness is 75 (Shore A), tensile strength is 35 kgf / cm ^{2 and} elongation is 11 mm.
3% (JIS K 6301 No. 1 dumbbell), tensile strength to mortar (JIS A 5758), the strength at break was 27 kgf / cm ² , and the adherend broke material, and the elongation at that time was 27%.

The joint filling step starts with a masking tape treatment around the joint, and is followed by joint filling with a caulking gun. After the filling is completed, the masking tape is removed, and the process ends. Curing of the joint material was completed in about 3 days, and the pedestrian bridge was able to walk on the bridge surface, providing a waterproof bridge and a tiled bridge surface that sufficiently followed the joint movement.

In addition to the embodiment shown in FIG. 1, as shown in FIG. 2, up to the cement mortar layer 16 for adjusting the foundation, the surface of the base concrete layer 14 is exposed, and the surface is covered with keren (by a grinder or the like). ) Adjust the unevenness, apply the elastic adhesive 18 on it with a thickness of about 1 mm, attach the surface finishing material 10a such as a tile, and complete the bonding process.
The repair was performed by the procedure of filling the joint material 22 into the joint material 22, and a favorable footbridge surface was obtained as in the case of FIG.

[0043]

As described above, according to the present invention, it is possible to repair and renovate a pedestrian bridge bridge surface capable of withstanding severe conditions outdoors centering on vibration, and to greatly shorten the construction period. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing a partial cross-sectional structure of a pedestrian overpass bridge surface which has been renovated according to an embodiment of the method of the present invention.

FIG. 2 is an explanatory cross-sectional view showing a partial cross-sectional structure of a pedestrian overpass modified by another embodiment of the method of the present invention.

FIG. 3 is a cross-sectional explanatory view showing a partial cross-sectional structure of a pedestrian bridge prepared by a conventional method.

FIG. 4 is an explanatory cross-sectional view showing a partial cross-sectional structure of a pedestrian overpass bridge surface that has been repaired using a cement-based adhesive. 10, 10a Surface finishing material 12 Cement-based adhesive 14 Base material 15 Cement-based joint material 16 Cement mortar layer for ground adjustment 18 Elastic adhesive 20 Joint material 17, 22 Joint W Footbridge bridge surface

Claims (9)

(57) [Claims] When repairing a pedestrian bridge bridge surface composed of a base material layer, a cement mortar layer for adjusting a groundwork, a cement-based adhesive layer, and a surface finishing material, the surface finishing material and the cement-based adhesive are peeled off to adjust the groundwork. A method of repairing a bridge surface of a pedestrian bridge, comprising: adjusting the surface of a cement mortar layer for terrain, applying an elastic adhesive to the surface of the cement mortar layer for adjusting the foundation, and attaching a surface finishing material such as a tile. 2. A method for repairing a pedestrian bridge bridge surface comprising a base material layer, a foundation mortar layer, a cement-based adhesive layer, and a surface finishing material. Take off the layers and
A method for repairing a bridge over a pedestrian bridge, comprising: adjusting the surface of a base material layer to have irregularities, applying an elastic adhesive to the surface of the base material layer, and attaching a surface finishing material such as a tile. 3. The method according to claim 1, wherein the joints between the surface finishes are filled with joints. 4. The method according to claim 3, wherein said joint is an elastic joint. 5. The viscosity of the elastic joint material is 300 to 50,000.
5. The method according to claim 4, wherein the index for evaluating thixotropic properties is set in a range of 3.0 to 5.0 and a hardness of 60 to 80 (Shore A). 6. A repair structure for a bridge over a pedestrian bridge repaired by the method according to claim 1, comprising a base material layer, a cement mortar layer for adjusting a foundation, an elastic adhesive layer, and a surface finishing material. 7. A joint material filled in joints between the base material layer, the cement mortar layer for adjusting the foundation, the elastic adhesive layer, the surface finishing material, and the surface finishing material. The repair structure of the pedestrian bridge bridge surface repaired by the method described. 8. A repair structure for a bridge over a pedestrian bridge, comprising a base material layer, an elastic adhesive layer, and a surface finishing material, and repaired by the method according to claim 2. 9. A repairing method according to claim 3, 4 or 5, comprising a base material layer, an elastic adhesive layer, a surface finishing material, and a joint material filled in a joint between the surface finishing materials. Repair structure for pedestrian bridges.