JP2010138650A - Method of protecting surface of bridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of protecting the surface of a bridge which reduces man-hours to shorten a construction period, cuts cost, and shortens a period of imposing traffic regulation for construction work. <P>SOLUTION: A urethane-based resin material is sprayed on a crack 11 on a joist 10 of a bridge 1 using a static spray to form a layer of a protective film 20 formed of a urethane resin on the crack 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for protecting a surface of a bridge.

  In general, a bridge is damaged due to deterioration, so that it needs to be repaired. For example, there was a problem that free lime was washed away due to the neutralization of concrete and the infiltration of moisture due to cracking, and the rebars corroded and expanded, causing the concrete to rise and fall.

Therefore, conventionally, a plurality of layers of protective films are formed on the surface of the bridge to protect the surface of the bridge (see, for example, JP-A-61-191706; Patent Document 1).
JP 61-191706 A

  However, in the conventional method for protecting the surface of a bridge, it is necessary to form a plurality of protective films, which increases man-hours, lengthens the construction period, increases costs, and regulates road traffic for work. There was a problem of prolonged.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a bridge surface protection method capable of reducing the number of steps, shortening the construction period, reducing the cost, and shortening the road traffic regulation for work.

  In order to solve the above-mentioned problem, the surface protection method for a bridge according to the present invention mixes a urethane-based resin material using a static spray device and sprays it on the surface of the bridge. One protective film is formed.

  Here, the static spray device refers to a device that mixes and sprays a plurality of materials constituting the urethane-based resin with static stirring.

  According to the bridge surface protection method of the present invention, the urethane resin material is mixed using a static spray device and sprayed onto the surface of the bridge, and the protective film made of the urethane resin is applied to the surface of the bridge. Since a single layer is formed, it is not necessary to form a plurality of protective films, and the number of steps can be reduced, the construction period can be shortened, the cost can be reduced, and the road traffic regulation for work can be shortened.

  In addition, since the static spray device is used, even if a plurality of materials for forming the urethane-based resin are used having a high viscosity, the plurality of materials can be sufficiently mixed and sprayed. For this reason, the said urethane type resin can be made into a high viscosity, and when spraying urethane type resin on a bridge, the amount of scattering of urethane type resin can be decreased, and the curing for prevention of scattering can be made unnecessary.

  In addition, the toughness of the urethane-based resin can be increased by using a urethane-based resin material with high viscosity, so that the tensile strength and elongation of the protective film increase, and the protective film has an opening width of cracks in the bridge. It is possible to suppress the progress of cracks in the bridge following the change in

In the bridge surface protection method of one embodiment, the urethane resin is a mixture of a modified isocyanate and a modified polyol,
The modified isocyanate is at least one of an isocyanate prepolymer, 4,4′diphenylmethane diisocyanate (MDI) and bis (2-ethylhexyl) phthalate,
The modified polyol is at least one of polyether polyol, diethyltoluenediamine, and 1,4 butanediol.

  According to the bridge surface protection method of this embodiment, by using a static spray device, the modified isocyanate and the modified polyol are statically mixed and sprayed onto the surface of the bridge, thereby protecting the urethane resin protective film, It can be formed by drying quickly after application without scattering.

  In addition, at least one of isocyanate prepolymer, 4,4′diphenylmethane diisocyanate (MDI) and bis (2-ethylhexyl) phthalate is used as the modified isocyanate, and polyether polyol, diethyltoluenediamine are used as the modified polyol. By using at least one of 1,4 butanediol, it is possible to form a urethane resin that is suitable for a protective film for bridges and that has little scattering during spraying.

  In the bridge surface protection method of one embodiment, the urethane-based resin material is maintained at a temperature in the range of 10 ° C to 25 ° C.

  According to the bridge surface protection method of this embodiment, the urethane-based resin material maintained at a temperature in the range of 10 ° C. or more and 25 ° C. or less is mixed with a static spray device and sprayed onto the surface of the bridge, so that the spray position It is possible to effectively prevent the inconvenience that the resin scatters around the periphery.

  Here, when the temperature of the urethane-based resin material is less than 10 ° C., the curing reaction of the resin material becomes insufficient, and there is a disadvantage that the protective film is defective because the resin is not formed normally. On the other hand, when the temperature of the urethane-based resin material exceeds 25 ° C., a disadvantage that the resin scatters occurs.

  In the bridge surface protection method according to an embodiment, the urethane resin material is held in a holding container provided with a heat insulating material.

  According to the bridge surface protection method of this embodiment, the temperature of the urethane resin material during mixing and spraying can be appropriately maintained by holding the urethane resin material in the holding container provided with the heat insulating material. , The occurrence of scattering can be effectively prevented.

  In the bridge surface protection method of one embodiment, the protective film is formed on the concrete member of the bridge.

  According to the bridge surface protection method of this embodiment, since the protective film is formed on the concrete member of the bridge, peeling of the concrete member can be prevented.

  In one embodiment of the bridge surface protection method, the protective film is formed on the metal member of the bridge.

  According to the bridge surface protection method of this embodiment, since the protective film is formed on the metal member of the bridge, corrosion protection of the metal member can be prevented.

  In the bridge surface protection method of one embodiment, the protective film is formed on the resin pipe of the bridge.

  According to the bridge surface protection method of this embodiment, since the protective film is formed on the resin pipe of the bridge, water leakage from the resin pipe can be prevented.

  According to the bridge surface protection method of the present invention, the urethane resin material is mixed using a static spray device and sprayed onto the surface of the bridge, and a protective film made of urethane resin is applied to the surface of the bridge. Since a single layer is formed, it is not necessary to form a plurality of protective films, and the number of steps can be reduced, the construction period can be shortened, the cost can be reduced, and the road traffic regulation for work can be shortened.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 is a cross-sectional view showing a first embodiment of a surface protection method for a bridge according to the present invention. As shown in FIG. 1, an aerial work vehicle 3 is installed on a road 2 below a highway bridge 1, and an operator 4 rides on the aerial work vehicle 3 to perform work. .

  As shown in FIG. 2A, a crack 10 exists in the beam 10 as a concrete member of the bridge 1, and the crack 11 is repaired. After curing the cracked portion 11, a primer (not shown) is applied to a predetermined region including the cracked portion 11.

  Then, as shown in FIG. 2B, urethane resin is sprayed onto a predetermined region (the surface of the bridge 1) including the cracked portion 11, and a protective film 20 made of the urethane resin is further formed on the predetermined region. Complete the repair work.

  A static spray device is used for spraying the urethane resin. This spray device is a device that mixes and sprays a plurality of materials constituting the urethane-based resin with static stirring. Hereinafter, the urethane resin will be described as being composed of two types of materials, a modified isocyanate and a modified polyol.

  As shown in the side view of FIG. 3A and the plan view of FIG. 3B, the static spray device 30 includes two cartridge parts 31A and 31B, a compression part 32, a mixing part 33, a nozzle part 34, and a handle part 35. And have.

  Each of the two cartridge portions 31A and 31B is filled with two kinds of materials constituting the urethane resin. The cartridge parts 31A and 31B are detachable from the apparatus 30 and can be replaced with new ones when the filled material runs out.

  Two compression parts 32 are provided corresponding to each of the two cartridge parts 31A and 31B. The compression unit 32 applies pressure to the material in the cartridge units 31A and 31B with compressed air. The compression part 32 has the drive piston 36 arrange | positioned in a cylinder. The drive piston 36 is connected to a pressure piston 38 disposed in the cartridge portions 31A and 31B via a rod 37.

  The mixing unit 33 mixes the materials extruded from the two cartridge units 31A and 31B while stirring. The mixing unit 33 has a spiral flow path in the pipe. The materials extruded from the cartridge portions 31A and 31B are statically mixed over a spiral flow path over time to form a urethane resin.

  The nozzle part 34 blows out the urethane resin formed by mixing in the mixing part 33 to the outside.

  The handle portion 35 is gripped by an operator and operated to start and stop spraying. The handle portion 35 is connected to a compressor (not shown) via the first tube 41. The handle portion 35 is connected to the compression portion 32 via the second tube 42. The handle part 35 is connected to the nozzle part 34 via a third tube 43.

  When the coating operation is performed with the static spray device 30, the two cartridge portions 31A and 31B of the modified isocyanate and the modified polyol have a temperature of 10 ° C. or more and 25 ° C. or less until they are mounted on the static spray device 30. Keep in range. For example, when performing a spraying operation in the summer, the cartridge parts 31A and 31B are adjusted to a temperature of about 20 ° C. in advance, and are stored in a storage container having a polystyrene insulation material, etc., transported to the spraying operation position, and stored immediately before the spraying operation. Remove from the container and attach to the static spray device 30. Thereby, even when the outside air temperature is relatively high, the modified isocyanate and the modified polyol are mixed and sprayed at a temperature of 25 ° C. or lower. On the other hand, when performing a spraying operation in winter, the cartridge parts 31A and 31B are adjusted to a temperature of about 15 ° C. in advance, and are stored in a storage container having a polystyrene heat insulating material or the like and transported to the spraying operation position, immediately before the spraying operation. Remove from storage container and attach to static spray device 30. Thus, even when the outside air temperature is relatively low, the modified isocyanate and the modified polyol are mixed and sprayed at a temperature of 10 ° C. or higher.

  By holding the modified isocyanate and the modified polyol at a temperature in the range of 10 ° C. or more and 25 ° C. or less before mounting on the static spray device 30, it is possible to effectively prevent inconvenience that the resin scatters around the spraying position. Was confirmed.

  Here, when the temperature of the modified isocyanate and the modified polyol is less than 10 ° C., the curing reaction of these resin materials becomes insufficient, the resin is not formed normally, and the protective film may be defective. On the other hand, when the temperature of the urethane-based resin material exceeds 25 ° C., a disadvantage that the resin scatters occurs. Therefore, it is preferable to hold the modified isocyanate and the modified polyol at a temperature in the range of 10 ° C to 25 ° C.

  Next, the operation of the spray device 30 will be described.

  Compressed air is sent from the compressor (not shown) to the handle portion 35 via the first tube 41. When the operation of starting spraying is performed with the handle portion 35, the compressed air is sent to the compression portion 32 via the second tube 42 and also sent to the nozzle portion 34 via the third tube 43.

The air sent to the compression unit 32 pushes the drive piston 36 to the left side in the figure, and pushes the pressure piston 38 to the left side in the figure via the rod 37. The pressurizing piston 38 applies pressure to the material in the cartridge portions 31A and 31B. The pressure applied to the material by the pressurizing piston 38 is set to about 0.7 N / cm ² . The two materials subjected to pressure are statically mixed when passing through the spiral flow path of the mixing unit 33 to form a urethane-based resin.

  The urethane-based resin that has reached the nozzle part 34 is blown out by the ejector action of the compressed air sent from the handle part 35 to the nozzle part 34 via the third tube 43.

  The amount of urethane-based resin blown from the nozzle part 34 is set to be about 1 kg when the material temperature is 25 ° C. In addition, the reaction time from the start of mixing of the two materials in the static spray device 30 to the blowing is set to about 5 seconds. Thus, the two urethane resin materials are sufficiently mixed so that they can be sprayed to the extent that they adhere to the painted surface when blown from the nozzle portion 34, and curing can be advanced to such an extent that no scattering occurs. .

  According to the bridge surface protection method having the above-described configuration, the urethane-based resin material is mixed using the static spray device 30 and sprayed onto the surface of the bridge 1 to protect the surface of the bridge 1 from the urethane-based resin. Since the film 20 is formed in a single layer, it is not necessary to form a plurality of protective films 20, and the number of man-hours can be reduced, the work period can be shortened, the cost can be reduced, and the road traffic regulation for work can be shortened.

  Moreover, since the protective film 20 is formed on the beam 10 as the concrete member of the bridge 1, it is possible to prevent the concrete member from peeling off.

  Further, since the static spray device 30 is used, even if a plurality of materials constituting the urethane-based resin are used with a high viscosity, the plurality of materials can be mixed and sprayed. Therefore, the urethane resin can be made high in viscosity, and when the urethane resin is sprayed on the bridge 1, the amount of the urethane resin scattered can be reduced, and the curing for preventing scattering can be eliminated.

  Further, since a urethane resin having high toughness can be formed, the tensile strength and elongation rate of the protective film 20 are increased, and the protective film 20 follows the change in the crack opening width of the bridge 1 to crack the bridge 1. Can be suppressed.

  Moreover, since the mixing time of these materials can be made relatively long by mixing the materials statically in the mixing unit 33 of the spray device 30, the urethane resin is brought into a semi-cured state at the outlet of the mixing unit 33. It can be cured in a short time after spraying. Thus, both quick drying and increase in elongation can be achieved.

  In addition, since a two-liquid collision mixing type spray apparatus mixes a low-viscosity liquid agent, when spraying the mixed liquid agent, there is a disadvantage that the amount of scattering increases and curing for preventing scattering is necessary. . In addition, the two-liquid collision mixing type spray device requires a heater and a heater control unit in addition to the compressor necessary for the static spray device, and there is a problem that the number of devices used is increased. On the other hand, according to the present embodiment, the surface protection method for the bridge can be executed with a small amount of effort and with a small amount of equipment, without performing curing for preventing scattering.

  Next, the properties and effects of the urethane resin of the present invention and the coating agent of the comparative example are compared.

Table 1 shows the properties of the urethane resin of the embodiment and the coating agents (sample A to sample D) of the comparative example. In Table 1, the viscosity is a value measured at an ambient temperature of 25 ° C.

  Here, modified isocyanate can be used as A agent of urethane type resin. As the modified isocyanate, at least one of an isocyanate prepolymer, 4,4′diphenylmethane diisocyanate (MDI), and bis (2-ethylhexyl) phthalate can be used. In this embodiment, bis (2-ethylhexyl) phthalate is adopted as the agent A. Bis (2-ethylhexyl) phthalate is available, for example, as DOP (trade name) manufactured by Daihachi Chemical Industry Co., Ltd. Moreover, a modified polyol can be used as B agent of urethane type resin. As the modified polyol, at least one of polyether polyol, diethyltoluenediamine and 1,4 butanediol can be used. In this embodiment, diethyltoluenediamine and 1,4 butanediol are employed as the B agent. Diethyltoluenediamine is available, for example, as DETDA (trade name) manufactured by Albemarle Japan Co., Ltd., and 1,4-butanediol as a modified polyol is 1.4-BD (trade name) manufactured by Mitsubishi Chemical Corporation. Is available as

Table 2 shows the characteristics of the urethane resin of this embodiment and the coating agents (sample A to sample D) of the comparative example.

  As can be seen from Table 2, the urethane resin of this embodiment satisfies the standard values for all of the tensile strength, elongation, adhesion strength, and coating thickness. On the other hand, in the coating agent of the comparative example (sample A to sample D), the reference value is not satisfied with respect to at least one of tensile strength, elongation rate, adhesion strength, and coating film thickness.

(Second Embodiment)
In the second embodiment of the bridge surface protection method of the present invention, the protective film 20 similar to that of the first embodiment is formed on the metal member of the bridge. That is, the protective film 20 is formed on the metal member of the bridge by the same method as in the first embodiment. An example of the metal member is a rail.

  According to this embodiment, the protective film 20 can be formed on a rail as a metal member of a bridge with a small number of devices and with a small number of man-hours and without curing. Therefore, the railing of the railings can be prevented quickly and inexpensively by the traffic regulation of the lanes along the railings.

(Third embodiment)
In the third embodiment of the bridge surface protection method of the present invention, a protective film 20 similar to that of the first embodiment is formed on the resin pipe of the bridge. That is, the protective film 20 is formed on the resin pipe of the bridge by the same method as in the first embodiment. An example of the resin pipe is a road drainage pipe made of vinyl chloride.

  According to this embodiment, the protective film 20 can be formed on a road drain pipe of a bridge with a small number of devices and with a small number of man-hours without curing. Therefore, leakage from the road surface drain pipe can be prevented quickly and inexpensively due to the short traffic regulation of the lane located below the road surface drain pipe.

  In addition, this invention is not limited to the above-mentioned embodiment. That is, the same method as in the first embodiment can be applied to any place on the surface of a bridge component such as a concrete member other than a beam, a metal member other than a rail, or a resin pipe other than a vinyl chloride pipe. A protective film can be formed.

It is sectional drawing which shows 1st Embodiment of the surface protection method of the bridge | bridging of this invention. It is the perspective view which looked at the mode before spraying urethane type resin on the crack part of a beam from the lower side of the beam. It is the perspective view which looked at the mode after spraying urethane type resin on the crack part of a beam from the lower side of the beam. It is a side view which shows a static type spray apparatus typically. It is a top view which shows a static type spray apparatus typically.

Explanation of symbols

1 Bridge 10 Beam (concrete member)
20 Protective film 30 Static spray device

Claims (7)

  A surface protection method for a bridge characterized in that a urethane-based resin material is mixed using a static spray device and sprayed onto the surface of the bridge, and a protective film made of urethane-based resin is further formed on the surface of the bridge. . The bridge surface protection method according to claim 1,
The urethane resin material is a modified isocyanate and a modified polyol,
The modified isocyanate is at least one of an isocyanate prepolymer, 4,4′diphenylmethane diisocyanate (MDI) and bis (2-ethylhexyl) phthalate,
The method for protecting a surface of a bridge, wherein the modified polyol is at least one of polyether polyol, diethyltoluenediamine, and 1,4 butanediol. The bridge surface protection method according to claim 2,
A method for protecting a surface of a bridge, wherein the urethane-based resin material is maintained at a temperature in a range of 10 ° C to 25 ° C. The bridge surface protection method according to claim 3,
A method for protecting a surface of a bridge, wherein the urethane resin material is held in a holding container provided with a heat insulating material. The bridge surface protection method according to claim 1,
A method for protecting a surface of a bridge, comprising forming the protective film on a concrete member of the bridge. The bridge surface protection method according to claim 1,
A method for protecting a surface of a bridge, comprising forming the protective film on a metal member of the bridge. The bridge surface protection method according to claim 1,
A method of protecting a surface of a bridge, comprising forming the protective film on a resin pipe of the bridge.

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