JP2013096104A - Coating method for mortar and vibration reception structure coated with mortar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating method for mortar that hardly causes deformation, drooping, and peeling of mortar due to vibrations even when a substrate surface of a vibration reception structure continuously receiving vibrations like a road bridge in service is coated with the mortar, and vibration reception structure coated with the mortar.SOLUTION: A specific resin sheet is arranged on the substrate surface of the vibration reception structure, and a resin sheet surface is coated with the mortar. It is suitable that a sheet arrangement process and a mortar coating process are in specific order.Further, it is suitable that the soft resin sheet has specific hardness. Furthermore, it is suitable that the mortar is fireproofing mortar.

Description

  The present invention relates to a mortar coating method and a vibration receiving structure coated with mortar.

  The surface of the structure may be coated with a mortar such as a fireproof mortar. When the structure continuously vibrates like a road bridge, even if the underlying surface of the structure is covered with mortar, the mortar may peel off from the surface of the structure due to vibration. This is when the stress applied to the mortar by vibration exceeds the strength of the mortar (for example, adhesive strength, compressive strength, bending strength, shear strength, etc.) before it reaches sufficient strength after the mortar is cured. Then, a part or all of the coated mortar is deformed or drooped, causing destruction or peeling, or peeling off.

  Now, as a method for preventing the mortar from peeling off from the surface of the structure, for example, a method of sticking a fiber sheet on the mortar surface (see, for example, Patent Document 1), an epoxy resin, a urethane resin, an acrylic resin or the like on the mortar surface. And a method of providing a reinforcing layer formed of a primer layer and a urethane cured product (for example, see Patent Document 2). These methods may be effective when mortar is coated on the underside of the underlying surface, that is, when mortar is coated on the underside of the ceiling or the ridge of the structure. However, when the mortar is always covered on the surface of a structure that is subject to vibration unless the entire vehicle is closed, such as a road bridge in which the structure is in service, The mortar coated on the lower surface of the ground surface is subjected to vibration before the coated mortar has sufficient strength, and even if the above-described method for preventing peeling is applied, the mortar is peeled off, peeled off or scraped off from the ground surface. There was a high risk of it. Of course, such a problem will not occur if the mortar is covered with the entire vehicle for the time until the coated mortar becomes sufficiently strong, but this will not occur, but there will be extra fuel consumed due to traffic congestion and detours. Due to the increase in social loss such as the generation of carbon dioxide based on the above and an increase in transportation cost, the vehicle is often not closed for a sufficient time to cover the surface of the structure with mortar.

  Therefore, even if the mortar is coated on the ground surface of a structure that continuously vibrates, such as a road bridge in which the structure is in service (sometimes referred to as “a vibration receiving structure” in this specification), There has been a demand for a mortar coating method and a mortar-coated structure in which the mortar is difficult to peel off.

JP 2008-255517 A JP 2008-285972 A

  An object of the present invention is to provide a solution to the above problem, that is, a mortar coating method and a vibration receiving structure coated with mortar. More specifically, the present invention is a case where the mortar is deformed by vibration even when the ground surface of the receiving structure continuously vibrates, such as a road bridge in which the structure is in service, It is an object of the present invention to provide a mortar coating method that hardly causes dripping, breaking, peeling or peeling, and a vibration receiving structure coated with mortar.

As a result of diligent investigations by the present inventor for solving the above-mentioned problems, the present invention provides the above-mentioned problems by disposing a specific resin sheet on the base surface of the vibration receiving structure and coating the resin sheet surface with mortar. The present invention was completed by finding out to solve the problem. The present invention is a mortar coating method represented by the following (1) to (4) and a vibration receiving structure coated with the mortar represented by (5) and (6).
(1) A mortar covering method comprising: a step of disposing a soft resin sheet on a base surface of a vibration receiving structure; and a step of covering the soft resin sheet surface with mortar.
(2) The mortar coating method according to (1), wherein the mortar coating step is performed after the sheet disposing step.
(3) The mortar coating method according to (1) or (2), wherein the soft resin sheet is a resin sheet having a Shore D hardness of 60 or less.
(4) The mortar coating method according to any one of (1) to (3), wherein the mortar is a fireproof coating mortar.
(5) A vibration receiving structure having a soft resin sheet on the base surface of the structure and further coated with a mortar having a mortar on the soft resin sheet surface.
(6) A vibration receiving structure coated with the mortar of (5) above, wherein the surface of the soft resin sheet is provided with the mortar by any one of the mortar coating methods (1) to (3).

  According to the present invention, even when the mortar is coated on the ground surface of a receiving structure with continuous vibration, such as a road bridge in which the structure is in service, the mortar is deformed or drooped by vibration, A mortar coating method and a vibration receiving structure coated with mortar that are unlikely to be broken, peeled off or peeled off are obtained. Moreover, according to this invention, the vibration receiving structure provided with the effect of the mortar coat | covered on the surface is obtained. For example, when the mortar to be coated is a fireproof coated mortar, a vibration receiving structure having fire resistance is obtained.

It is the schematic of a stainless steel wire mesh. It is typical sectional drawing of a test body part. It is a typical perspective view of the test body for peeling confirmation tests. It is the typical top view which showed the vibration location of the test body for peeling confirmation tests. It is a side view of the used tapping screw. It is a typical perspective view of a part of the test body for peeling confirmation test before covering mortar.

  The mortar coating method of the present invention includes a step of placing a soft resin sheet on the base surface of the vibration receiving structure (sheet placement step), and a step of coating the surface of the soft resin sheet with mortar (mortar coating step). This is a mortar coating method.

  The mortar in the present invention refers to a material containing a binder and an aggregate, and examples thereof include cement mortar, polymer mortar, polymer cement mortar, and spray rock rock wool. As the binder, either an organic binder or an inorganic binder can be used, or both can be used in combination. Examples of the organic binder used in the present invention include natural resins, synthetic resins and raw materials thereof, such as ethylene, butadiene, vinyl chloride, styrene, vinyl acetate, long chain fatty acid vinyl esters having 4 or more carbon atoms, siloxane, acrylonitrile, acrylics. Preferred examples include one or more polymers selected from acid alkyl esters, alkyl methacrylate esters, and derivatives thereof, or epoxy resins, unsaturated polyester resins, asphalts, rubber asphalts, and the like. Examples of the polymer include acrylonitrile / styrene copolymer, styrene / alkyl acrylate copolymer, ethylene / vinyl chloride / vinyl acetate copolymer, vinyl acetate / neodecanoic acid vinyl ester (trade name: Veova) Preferred is a copolymer, a copolymer selected from vinyl acetate / alkyl acrylate copolymer, alkyl acrylate / silicone copolymer and ethylene / vinyl acetate copolymer. The organic binder may be in the form of a liquid, an emulsion, or a solid, but is preferably a liquid, an emulsion, or a powder because of its good miscibility with other materials.

  Examples of the inorganic binder used in the present invention include hydraulic cements such as Portland cement, alumina cement, mixed cement and super-hard cement, pneumatic cements such as slaked lime and gypsum, and sulfur. Particularly, hydraulic cement is preferable because it is easy to handle and can easily obtain strength at an early stage. Examples of the hydraulic cement include various normal Portland cements such as normal strength, very early strength, low heat and moderate heat, ecocement, and portland cement or ecocement, and fly ash, blast furnace slag, silica fume, or limestone fine powder. Various mixed cements mixed with powder, etc., super-fast cements such as “Jet Cement” (trade name) manufactured by Taiheiyo Cement Co., Ltd. and “Jet Cement” (trade name) manufactured by Sumitomo Osaka Cement Co., alumina cement, etc. One kind or two or more kinds can be used.

  The aggregate used in the present invention may be any aggregate that can be used for mortar and concrete. For example, river sand, sea sand, mountain sand, crushed sand, artificial fine aggregate, slag fine aggregate, regenerated fine bone Wood, slag fine aggregate, quartz sand, stone powder, river gravel, land gravel, crushed stone, artificial coarse aggregate, recycled coarse aggregate, slag coarse aggregate, etc., one or more of these can be used is there. It is preferable that the mortar used in the present invention contains a lightweight aggregate because the mortar is less likely to be deformed, drooped or peeled off due to vibration. As this lightweight aggregate, either an inorganic lightweight aggregate or an organic lightweight aggregate may be used, and they can be used in combination. Examples of inorganic lightweight aggregates include expanded vermiculite, perlite, expanded shale, pumice, shirasu balloon, etc., which are foamed or expanded natural minerals, foamed silica gel, and various types of slag. Artificial lightweight aggregates such as those obtained by granulating and foaming glass scrap, and those obtained by granulating and foaming clay powder can be used. In addition, natural lightweight aggregates such as blast furnace slag, basalt, andesite, and diorite that are by-produced from the blast furnace at the steelworks are melted in a cupola, electric furnace, etc., and then fluid pressure such as centrifugal force, air, and water vapor is used. Rock wool granular cotton obtained by blowing and fiberizing rock wool (also referred to as rock wool, slag wool, mineral wool) into granules with a crusher or the like can also be used. As the organic light-weight aggregate, a solid material having a bulk specific gravity of 2 or less such as synthetic resin or rubber can be used, and preferable examples thereof include polystyrene, polyethylene, and polyethylene-vinyl acetate. Examples include polymers, polypropylene, polyurethane, polyvinyl chloride, polyvinylidene chloride, natural rubber, and synthetic rubber. As the shape, a granular material, a foam or the like can be used. Moreover, the organic lightweight aggregate (for example, calcium carbonate foam) containing the inorganic powder formed by mixing the inorganic powder such as calcium carbonate and fly ash with the organic material can be used.

  Examples of the soft resin sheet used in the present invention include a sponge-like resin sheet, a soft resin plate, and a soft resin fabric. As the resin used for the soft resin sheet, synthetic rubber such as silicone rubber, urethane rubber, styrene / butadiene rubber, butyl rubber, acrylic rubber, chloroprene rubber, natural rubber, soft polyethylene, soft polypropylene, soft polyvinyl resin, polystyrene, and the like are preferable. It can be illustrated as a thing. The soft resin sheet used in the present invention is preferably a resin sheet having a Shore D hardness of 60 or less. The soft resin sheet used in the present invention preferably has a thickness of 0.5 to 20 mm, more preferably 1 to 15 mm, and still more preferably 2 to 10 mm. If the thickness of the soft resin sheet is less than 0.5 mm, the vibration of the structure is easily transmitted to the mortar covered, and if the thickness of the soft resin sheet is more than 20 mm, the sheet cannot be cut by a cutter or stagnation. The process is labor intensive.

  The method for disposing the soft resin sheet on the base surface of the vibration receiving structure is not particularly limited. For example, a method of fastening a soft resin sheet to the base surface of the structure after forming a soft resin sheet in accordance with the shape of the base surface of the vibration receiving structure, a base surface after stopping the soft resin sheet to the base surface of the vibration receiving structure There is a method of forming a soft resin sheet according to the shape of the above. When the base surface of the structure cannot be covered with a single soft resin sheet, the structure is covered with a plurality of soft resin sheets. At this time, each soft resin sheet may be partially or entirely overlapped, or a gap of about 1 cm may be left. As a method for fastening the soft resin sheet to the base surface of the vibration receiving structure, adhesive bonding, welding, nailing, hammering, stapling, screwing, bolting, or the like can be used. Rather than stopping the entire surface of the soft resin sheet on the base surface of the vibration receiving structure with an adhesive or the like, it is preferable to partially stop the soft resin sheet on the base surface because the vibration of the structure is less likely to be transmitted to the covering mortar. For example, a method of adhering and adhering to the back surface (surface on the base surface side) of a soft resin sheet in a dot or line form, a method of welding in a dot or line form, nailing, hammering, stapling, screwing, bolting, etc. is there.

  In the mortar coating step, the method for coating the surface of the soft resin sheet with mortar is not particularly limited. For example, there are a spraying method, a lacquering method, a method of installing a mold, and a method of driving or filling mortar between the mold and the soft resin sheet. It is preferable to cover the surface of the soft resin sheet with a mortar by spraying or / and glazing because it is not necessary to install a mold. In addition, a primer such as styrene / butadiene rubber emulsion, acrylic resin emulsion, or epoxy resin is applied to the surface of the soft resin sheet before coating the mortar for the purpose of increasing the adhesive force between the soft resin sheet and the mortar to be coated. Also good.

  The mortar covering method of the present invention includes a steel road bridge, a reinforced concrete road bridge, a road bridge composed of a composite structure of concrete and steel shell, a steel railway bridge, a reinforced concrete railway bridge, a reinforced concrete turbine building, a steel factory roof, etc. It can be suitably used for new construction, repair work or reinforcement work. Moreover, the mortar coating method of the present invention can be used for any of the upper surface, the lower surface, the wall surface, and the interior of these vibration receiving structures. The road bridge and the railway bridge include a viaduct.

  Moreover, the vibration receiving structure covered with the mortar of the present invention is a structure in which the base surface of the vibration receiving structure is provided with a soft resin sheet, and the soft resin sheet surface is further covered with a mortar provided with the mortar. . The soft resin sheet and mortar here are the same as those described above. The structure coated with the mortar of the present invention is preferably a vibration receiving structure in which the surface of the soft resin sheet provided on the base surface of the structure is coated with mortar by any one of the mortar coating methods described above. When the mortar is a fireproof coating mortar, the vibration receiving structure covered with the mortar of the present invention is preferably a fireproof structure.

[Example 1]
[Resin sheet hardness test]
In the resin sheet used for the peeling confirmation test, the hardness was measured according to JIS Z 2246 “Shore hardness test”. The test piece was 40 mm × 40 mm × 10 mm, and a D-type tester was used. The measurement results are shown in Table 1.

[Preparation of test specimen for peeling confirmation test]
Common steel materials used for steel bridges include general structural rolled steel materials (JIS G 3101), rolled steel materials for welded structures (JIS G 3106), and weather resistant hot rolled steel materials for welded structures (JIS G 3114). In this test, a general structural rolled steel (JIS G 3101) was used. A test body was prepared that simulated the case where a steel bridge deck girder was coated with a fireproof coating material (mortar). The stainless steel shown in FIG. 1 is a resin sheet (flat plate) 11 in which a 300 × 2000 × 9 mm steel plate (SS400) is applied with reference to the lower part of the H-shaped steel flange in the steel bridge deck girder and a resin emulsion (primer) is applied to this steel plate. The metal mesh 2 (line diameter 1.6 mm, line interval 50 mm, lattice interval (opening) 48.4 mm) and the tapping screw 5 shown in FIG. At this time, it arrange | positioned so that the surface which apply | coated the primer of the resin sheet 11 may contact the stainless steel metal-mesh 2. The interval between the tapping screws (the distance between the screw center portions) was 300 mm in the longitudinal direction of the steel sheet and 200 mm in the lateral direction of the steel sheet. That is, using 12 tapping screws 5, the resin sheet 11 together with the stainless steel wire mesh 2 was fixed to the steel plate 1 by screwing. At a position where the tapping screw 5 of the steel plate 1 is attached, a hole (a lower hole 9) having a depth of 7 mm was previously drilled using a blade having a diameter of 4.6 mm. Further, when screwing, the flat washer 6 was sandwiched between the tapping screw 5 and the stainless steel wire mesh 2. The resin sheet 11 used had a shape of 300 × 2000 mm and a thickness of 2 mm, 5 mm, and 10 mm. In addition, the stainless steel mesh 2 used was partially dented to form a metal mesh attachment portion 12, and a tapping screw was used in this portion to screw the steel sheet 1 together with the resin sheet 11. At this time, the distance from the resin sheet 11 to the upper end part of the stainless steel metal mesh 2 was 15 mm. Further, the tapping screw 5 is provided with a groove 14 provided for tapping. FIG. 6 shows a schematic perspective view of a part of the test specimen for the peeling confirmation test before coating the mortar.

  After that, after spraying a commercially available fireproof coating material (fireproof coating mortar) containing ordinary Portland cement, expanded vermiculite and an admixture so as to embed the stainless steel wire mesh 2, the fireproof coating material of the fireproof coating material is made with a hammer. The test specimen was flattened so as to have a thickness of 25 mm. As a test sample of a comparative example, without using a resin sheet, a primer was applied to a steel plate, a stainless steel wire mesh tapping screw was attached, and a test sample coated with a fireproof coating material was prepared in the same manner as the other test samples. The shape of any fireproof covering material layer is 300 × 1800 × 25 mm. This mortar coating process was performed in a constant temperature room at 20 ° C.

[Peeling confirmation test]
After leaving the prepared test body for 1 hour as it is, the test body was gently turned over so that the fireproof coating layer was on the lower side of the steel plate, and the position of 50 mm from the end of the steel plate was a steel material (fulcrum) 4 as shown in FIG. It supported like. A 1 kg steel hammer was shaken down from the vertical position only by its own weight, and vibration was applied to the steel plate 1. The place where the hammer is shaken down (vibration place 8) is the lattice points (shown by ○ in the figure) at intervals of 100 mm shown in FIG. Was added. After the addition of vibration, the presence or absence of peeling of the fireproof coating material (mortar) was visually confirmed. The presence or absence of peeling is shown in Table 2 together with the type and thickness of the resin sheet used. The fireproof coating material (mortar) was uncured immediately after the vibration was applied.

  From the test results, the specimens (Nos. 1 to 12) corresponding to the examples of the present invention did not show any deformation, dripping or peeling of the fireproof coating material due to vibration, but the specimens corresponding to the comparative examples (Nos. 13 to 13). In 15), the fireproof coating material was peeled off due to vibration.

  The mortar covering method of the present invention is a repair work for a structure (receiving structure) having continuous vibration such as a road bridge in service, a railway bridge in service, a turbine building in operation, or a factory building in operation. Can be used for reinforcement work. Moreover, the vibration receiving structure covered with the mortar of the present invention can be used as a road bridge, a railway bridge, an operating turbine building, a factory building, and the like.

1 Steel plate (base of vibration receiving structure when imitating steel bridge deck girder)
2 Stainless steel wire mesh 3 Fireproof coating material (Fireproof mortar)
4 Steel (fulcrum)
5 Tapping screw 6 Flat washer 7 Lattice spacing (100 mm)
8 Excitation location 9 Pilot hole 10 Specimen 11 Resin sheet 12 Wire mesh attachment portion 13 Thickness 14 of fireproof covering material layer (fireproof covering mortar) 5 Groove provided for tapping

Claims (6)

  A mortar coating method comprising: a step of disposing a soft resin sheet on a base surface of a vibration receiving structure; and a step of covering the surface of the soft resin sheet with mortar.   The mortar coating method according to claim 1, wherein the mortar coating step is performed after the sheet disposing step.   The mortar coating method according to claim 1, wherein the soft resin sheet is a resin sheet having a Shore D hardness of 60 or less.   The mortar coating method according to claim 1, wherein the mortar is a fireproof coating mortar.   A vibration receiving structure comprising a soft resin sheet on a base surface of the vibration receiving structure and further coated with a mortar having a mortar on the surface of the soft resin sheet.   The vibration receiving structure coated with the mortar according to claim 5, wherein the soft resin sheet surface is provided with the mortar by the mortar coating method according to claim 1.

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