Method for removing hardened cement body

Abstract

To provide a method of removing a cement hardened body capable of increasing the reusability of construction materials.SOLUTION: The method of removing a cement hardened body 30 includes: a covering step of covering an entire non-stick surface 23 of a construction material 20 while overlapping a plurality of removable cover materials 40; a removing step of removing the cement hardened body 30 by immersing the construction material 20 in an acidic immersion liquid AS; and a removal step of removing the plurality of cover materials 40 from the non-stick surface 23. The plurality of cover materials 40 includes: a first cover material 41 configured to be able to block the acidic immersion liquid AS and configured to be attachable / detachable to / from the non-stick surface 23; and a second cover material 42 that is placed outside the first cover material 41, the second cover material 42 being configured to be able to block the acidic immersion liquid AS and configured to be able to maintain the adhesion between the second cover material and the non-stick surface 23, etc.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a method for removing a cement hardened body.

Background Art

[0002] Conventionally, as one of the technologies for reusing building materials removed from the outer wall, a technology for removing a cement hardened body by immersing a building material with a cement hardened body attached thereto in an acid solution has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above conventional technology, as described above, since a building material with a cement hardened body attached thereto is immersed in an acid solution, there is a risk that the surface of the building material where the cement hardened body is not attached will be discolored by the acid solution. Therefore, there is room for improvement from the viewpoint of the reusability of construction members such as building materials.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a method for removing a cement hardened body that can enhance the reusability of construction members.

Means for Solving the Problems

[0006] In order to solve the above-described problems and achieve the object, the method for removing a cement hardened body according to claim 1 is a removal method for removing the cement hardened body adhering to a construction member from the construction member, including: a covering step of covering the entire non-adhering surface of the surface of the construction member where the cement hardened body is not adhered with a plurality of detachable cover materials; a removal step of removing the cement hardened body adhering to the construction member by immersing the construction member covered with the plurality of cover materials in an acidic immersion liquid after the covering step; and a removal step of removing the plurality of cover materials from the non-adhering surface after the removal step. The plurality of cover materials include a first cover material configured to be able to block the acidic immersion liquid and configured to be detachable from the non-adhering surface, and a second cover material provided outside the first cover material, the second cover material being configured to be able to block the acidic immersion liquid and configured to be able to maintain the adhesion between the second cover material and the non-adhering surface or the first cover material. Include. In the covering step, cover the entire first non-adhering portion, which is at least the portion of the non-adhering surface opposite to the adhering surface to which the cement hardened body is adhered, and a part of the second non-adhering portion, which is the portion between the first non-adhering portion and the adhering surface, with the first covering material, and cover at least a part of the first non-adhering portion and the entire second non-adhering portion among the portions of the non-adhering surface with the second covering material.

[0007] The method for removing a cement hardened body according to claim 2 is the method for removing a cement hardened body according to claim 1, wherein The first covering material includes a tape material having water-stopping property and / or a putty material.

[0008] The method for removing a cement hardened body according to claim 3 is the method for removing a cement hardened body according to claim 1 or 2, wherein The second covering material includes a coating material having water-repellent property and / or an adhesive.

[0009] The method for removing a cement hardened body according to claim 4 is Claim 3 in the method for removing a cement hardened body according to claim, wherein The film thickness of the second covering material is set to 157 μm or more.

Advantages of the Invention

[0011] According to the method for removing a cement hardened body described in claim 1, a plurality of cover materials include a first cover material configured to be able to block an acidic immersion liquid and to be detachable from a non-adhering surface, and a second cover material provided outside the first cover material, the second cover material being configured to be able to block an acidic immersion liquid and to be able to maintain the adhesion between the second cover material and the non-adhering surface or the first cover material. Therefore, discoloration of the construction member can be suppressed by the first cover material and the second cover material, and the reusability of the construction member can be enhanced. In addition, the first cover material can be easily attached to and detached from the construction member, and the covering process and the removing process can be efficiently performed. Also, in the covering step, cover the entire first non-adhering portion, which is at least the portion of the non-adhering surface opposite to the adhering surface to which the cement hardened body is adhered, and a part of the second non-adhering portion, which is the portion between the first non-adhering portion and the adhering surface, with the first covering material, and cover at least a part of the first non-adhering portion and the entire second non-adhering portion among the portions of the non-adhering surface with the second covering material. Therefore, while ensuring the functions of the first covering material and the second covering material, the usage amounts of the first covering material and the second covering material can be reduced, and the manufacturing costs of the first covering material and the second covering material can be effectively reduced.

[0012] According to the method for removing a cement hardened body described in claim 2, Since the first covering material includes a tape material having water-stopping property and / or a putty material, the first covering material can be manufactured at a relatively low cost, and the manufacturing costs of a plurality of covering materials can be reduced.

[0013] According to the method for removing a cement hardened body described in claim 3, Since the second covering material includes a coating material having water-repellent property and / or an adhesive, the second covering material can be manufactured at a relatively low cost, and the manufacturing costs of a plurality of covering materials can be reduced.

[0014] According to the method for removing a cement hardened body described in claim 4, Since the film thickness of the second covering material is set to 157 μm or more, it becomes easier to ensure the function of the second covering material, and thus it becomes easier to ensure the quality of a plurality of covering materials.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0017] With reference to the accompanying drawings below, embodiments of the method for removing a cement hardened body according to the present invention will be described in detail. First, after explaining the basic concept of [I] the embodiment, [II] the specific content of the embodiment will be described, and finally, [III] modifications to the embodiment will be described. However, the present invention is not limited by the embodiments.

[0018] 〔I〕Basic Concept of the Embodiment First, the basic concept of the embodiment will be described. The embodiment generally relates to a removal method for removing a cement hardened body attached to a construction member from the construction member.

[0019] Here, the specific structure and type of the "construction member" are arbitrary. For example, it includes concepts such as exterior materials (such as tile-based exterior materials and brick-based exterior materials) and interior materials (such as tile-based interior materials and brick-based interior materials) attached to the framework of a structure (as an example, columns, walls, floors, or ceilings), etc. In the embodiment, it will be described as a tile-based exterior material for walls.

[0020] Also, the specific structure and type of the "structure" are arbitrary. For example, it includes concepts such as building structures such as office buildings, commercial facilities, public facilities, and apartment buildings and condominiums like apartment houses, and civil engineering structures such as tunnels and dams. In the embodiment, it will be described as an office building.

[0021] Moreover, the "cement hardened body" is used for attaching a construction member to the framework body described later. For example, it includes concepts such as a base material containing at least cement as a component, etc. In the embodiment, it will be described as a mortar-based base material.

[0022] Also, the specific use of the construction member from which the cement hardened body has been removed by this removal method is arbitrary. For example, it may be reused as an exterior material or an interior material on the framework of the structure to which the construction member was attached or on the framework of a different structure, or it may be used for other uses other than exterior materials or interior materials (as an example, as a fence material for flower beds, etc.).

[0023] 〔II〕Specific Contents of the Embodiment Next, the specific contents of the embodiment will be described.

[0024] (Configuration) First, the configuration of the framework of a structure (specifically, an office building) including a construction member to which the method for removing a cement hardened body according to the embodiment is applied will be described.

[0025] FIG. 1 is a diagram conceptually showing a housing according to an embodiment of the present invention, where (a) is a front view and (b) is a cross-sectional view taken along the line A-A.

[0026] In the following description, the X direction in FIG. 1 is the left-right direction of the housing (-X direction is the left direction of the housing, +X direction is the right direction of the housing), the Y direction in FIG. 1 is the front-rear direction of the housing (+Y direction is the front direction of the housing, -Y direction is the rear direction of the housing), and the Z direction in FIG. 1 is the up-down direction of the housing (+Z direction is the up direction of the housing, -Z direction is the down direction of the housing).

[0027] The housing 1 is a wall (for example, an outer wall, etc.) that constitutes a structure, and as shown in FIG. 1, it includes a housing main body 10, a construction member 20, and a cement hardened body 30.

[0028] (Configuration - Housing Main Body) The housing main body 10 is the basic structure of the housing 1. This housing main body 10 is formed of, for example, a long rectangular plate-like body made of concrete (as an example, made of reinforced concrete or prestressed concrete), and as shown in FIG. 1, it is provided such that its longitudinal direction is along the up-down direction and is fixed to an installation target (for example, a floor part, etc.) not shown.

[0029] (Configuration - Construction Member) The construction member 20 is configured using, for example, a known tile-based exterior material, etc., and as shown in FIG. 1, it is provided to cover the entire outer surface of the housing main body 10 (the entire front surface in FIG. 1) on the outside of the housing main body 10, and includes a construction member main body 21 and a surface film 22.

[0030] (Configuration - Construction Member - Construction Member Main Body) The construction member main body 21 is the basic structure of the construction member 20. This construction member main body 21 is configured using, for example, a known tile material (as an example, a rectangular tile material having a tile part and a joint part), etc., and as shown in FIG. 1, a plurality of them are arranged in parallel substantially along the left-right direction so as to cover the housing main body 10, and a plurality of them are also arranged in parallel substantially along the up-down direction.

[0031] Regarding the specific configuration of the construction member body 21, in the embodiment, it is configured as follows.

[0032] That is, as shown in FIG. 1, the entire outer surface of the construction member body 21 (the entire front surface in FIG. 1) is formed in a flat shape. However, it is not limited to this, and for example, it may be formed in a non-flat shape. Also, the entire inner surface of the construction member body 21 (the entire rear surface in FIG. 1) is formed in a non-flat shape, and specifically, it is formed to have a plurality of convex portions protruding rearward.

[0033] (Configuration - Construction Member - Surface Film) The surface film 22 is a film coated with glaze. As shown in FIG. 1(b), this surface film 22 is provided on the entire outer surface of the construction member body 21. Specifically, for example, glaze for exterior tile materials is applied to the entire outer surface of the construction member body 21 and baked to form it.

[0034] Here, "glaze" means a chemical used to enhance the decorativeness and strength of the construction member 20 and prevent dirt on the construction member 20. Specifically, it is a chemical composed of the RO2 component (for example, SiO2 component, etc.) that forms the skeleton of the glaze, the R2O3 component (for example, Al2O3 component, etc.) that connects with the construction member body 21 and forms part of the skeleton of the glaze, the RO component (CaO component, MgO component) that partially breaks the skeleton of the glaze and lowers the melting temperature, and the R2O component (Na2O component, K2O component, etc.).

[0035] Also, the specific type of "glaze" is arbitrary. For example, "transparent glaze" which is amorphous, "mat glaze / devitrified glaze" which contains fine crystals not incorporated in the amorphous phase, "crystal glaze" which contains large crystals, and "opal glaze" which has a plurality of amorphous phases, etc. are applicable.

[0036] Also, although the coating amount of the glaze is arbitrary, from the viewpoint of forming a uniform surface film 22, it is desirable to set it as small as possible. However, since it may vary depending on the type of glaze, the type of the construction member main body 21, etc., for example, it may be set based on experimental results, analysis results, etc.

[0037] (Configuration - Cement hardened body) The cement hardened body 30 is for attaching the construction member 20 to the housing body 10. This cement hardened body 30 is configured using, for example, a known mortar-based base material, and as shown in FIG. 1, it is provided between the housing body 10 and the construction member main body 21. Specifically, it is provided so as to cover the entire outer surface of the housing body 10.

[0038] (Method for removing cement hardened body) Next, a method for removing the cement hardened body 30 according to the embodiment will be described.

[0039] FIG. 2 is a diagram showing a preparation step of the method for removing the cement hardened body 30. FIG. 3 is a diagram showing a covering step of the method for removing the cement hardened body 30. FIGS. 4 to 6 are diagrams showing modified examples of the covering step of the method for removing the cement hardened body 30. FIG. 7 is a diagram showing a removal step of the method for removing the cement hardened body 30.

[0040] The method for removing the cement hardened body 30 according to the embodiment is a method for removing the cement hardened body 30 attached to the construction member 20 from the construction member 20. As shown in FIGS. 2, 3, and 7, it includes a preparation step, a covering step, a removal step, a removal step, and an immersion step.

[0041] (Method for removing cement hardened body - Preparation step) Returning to FIG. 2, first, the preparation step will be described.

[0042] The preparation step is a step for preparing to remove the cement hardened body 30 from the construction member 20.

[0043] Specifically, first, as shown in FIG. 2, using a known cutting tool (not shown), a part of the construction member 20 is cut together with the cement hardened body 30, and then, using a known peeling tool (not shown), the cut construction member 20 and the cement hardened body 30 are peeled from the building body 10. In this case, for example, in order to enhance the reusability of the construction member 20, it is desirable to cut the construction member 20 such that at least one or more tile portions of the construction member body 21 are included in the cutting region of the construction member 20, and to cut the joint portion of the construction member body 21 without cutting the tile portion of the construction member body 21.

[0044] Next, using a known cutting tool (not shown), a part of the cement hardened body 30 adhering to the cut construction member 20 is removed so that a plurality of cover members 40 described below can be easily covered on the cut construction member 20. More specifically, as shown in FIG. 2, a part of the portion of the cement hardened body 30 opposite to the construction member 20 side (in FIG. 2, a part of the rear portion of the cement hardened body 30) and a part of the side portion (in FIG. 2, a part of the left side portion, right side portion, upper side portion, or / and lower side portion of the cement hardened body 30) are removed.

[0045] Subsequently, the construction member 20 from which a part of the cement hardened body 30 has been removed is cleaned using a known waste (not shown).

[0046] (Method for Removing Cement Hardened Body - Covering Step) Next, the covering step will be described.

[0047] The covering step is a step of covering the entire surface 23 (hereinafter referred to as the "non - adhering surface 23") of the construction member 20 where the cement hardened body 30 is not adhered with a plurality of detachable cover members 40 after the preparation step.

[0048] Here, the specific configuration of the plurality of cover members 40 is arbitrary, but in the embodiment, as shown in FIG. 3, it includes a first cover member 41 and a second cover member 42.

[0049] Among these, the first cover material 41 is configured to be able to block the acidic immersion liquid AS described later, and is a cover material configured to be detachable from the non - adhering surface 23. This first cover material 41 is configured to include a tape material and / or a putty material having water - stopping properties. Specifically, based on the test results of the second cover material performance confirmation test to the fourth cover material performance confirmation test described later, it is composed of a cloth - adhesive tape. However, it is not limited to this. For example, as described in the prior application (Japanese Patent Application No. 2019 - 29760) by some of the inventors of the present application, it has been confirmed that an adhesive tape, a duct tape, and a putty for pipes also have performance substantially similar to that of a cloth - adhesive tape. Therefore, it may be composed of an adhesive tape, a duct tape, a putty for pipes, or a combination thereof.

[0050] Also, the second cover material 42 is configured to be able to block the acidic immersion liquid AS described later, and is a cover material configured to be able to maintain the adhesion between the second cover material 42 and the non - adhering surface 23 or the first cover material 41. This second cover material 42 is provided outside the first cover material 41 and is configured to include a water - repellent coating material and / or an adhesive. Specifically, based on the test results of the second cover material performance confirmation test to the fourth cover material performance confirmation test described later, it is composed of paraffin. However, it is not limited to this. For example, it may be composed of a resin - based adhesive, a silicone seal, or a combination thereof.

[0051] With such a configuration, the first cover material 41 and the second cover material 42 can be manufactured at a relatively low cost, and the manufacturing cost of the plurality of cover materials 40 can be reduced.

[0052] Also, regarding the specific content of the covering process, based on the test results of the second cover material performance confirmation test described later, it is carried out as follows in the embodiment.

[0053] First, attach the first cover material 41 to the non - adherent surface 23. The method of attaching this first cover material 41 is arbitrary. However, in the embodiment, as shown in FIG. 3, among the portions of the non - adherent surface 23, at least the whole of the portion 23a on the side opposite to the adherent surface 24 to which the cement hardened body 30 is attached (hereinafter referred to as the "first non - adherent portion 23a") and a part of the portion 23b between the first non - adherent portion 23a and the adherent surface 24 (hereinafter referred to as the "second non - adherent portion 23b") are covered with a single first cover material 41 (however, it is not limited to this, for example, it may be attached so as to be covered with a plurality of first cover materials 41).

[0054] Specifically, first, attach the single first cover material 41 to the first non - adherent portion 23a so as to cover the whole of the first non - adherent portion 23a with the single first cover material 41. Next, attach the single first cover material 41 to the second non - adherent portion 23b on the long - side side (specifically, the upper second non - adherent portion 23b and the lower second non - adherent portion 23b) so as to cover a part of it (as an example, the portion from the end on the first non - adherent portion 23a side of the second non - adherent portion 23b to the mid - point between the end and the opposite end). Then, attach the single first cover material 41 to the second non - adherent portion 23b on the short - side side (specifically, the left - hand second non - adherent portion 23b and the right - hand second non - adherent portion 23b) so as to cover a part of it (as an example, the portion from the end on the first non - adherent portion 23a side of the second non - adherent portion 23b to the mid - point between the end and the opposite end). In this case, by making a cut in the folded - back portion of the single first cover material 41 with a known cutting instrument (not shown), the single first cover material 41 can be easily attached to the second non - adherent portion 23b on the short - side side. Subsequently, press the single first cover material 41 against the non - adherent surface 23 with a known instrument or by hand to make the single first cover material 41 conform to the non - adherent surface 23.

[0055] This enables reduction of the usage amount of the first cover material 41 while ensuring the function of the first cover material 41, and effectively reduces the manufacturing cost of the first cover material 41.

[0056] However, it is not limited to this. For example, based on the test results of the fourth cover material performance confirmation test described later, as shown in FIG. 4, the entire first non-adhering portion 23a and substantially the entire part of each second non-adhering portion 23b (as an example, from the end on the first non-adhering portion 23a side to about 1 mm before the end on the opposite side of each second non-adhering portion 23b) may be attached so as to be covered with a single first cover material 41. Alternatively, as shown in FIG. 5, the entire first non-adhering portion 23a and the entire part of each second non-adhering portion 23b may be attached so as to be covered with a single first cover material 41.

[0057] Returning to FIG. 3, next, the second cover material 42 is attached to the first cover material 41 and / or the non-adhering surface 23. The method of attaching this second cover material 42 is arbitrary, but in the embodiment, as shown in FIG. 3, at least a part of the first non-adhering portion 23a and the entire second non-adhering portion 23b among the portions of the non-adhering surface 23 are attached so as to be covered with the second cover material 42.

[0058] Specifically, first, the second cover material 42 is sequentially attached to the first cover material 41 and / or the non-adhering surface 23 so as to cover the entire second non-adhering portion 23b (specifically, the upper second non-adhering portion 23b, the lower second non-adhering portion 23b, the left second non-adhering portion 23b, and the right second non-adhering portion 23b) by immersion in the liquid second cover material 42 or the like. Next, the second cover material 42 is attached to the first cover material 41 and / or the non-adhering surface 23 so as to cover the entire first non-adhering portion 23a with the second cover material 42 by applying the liquid second cover material 42 using a known brush or the like. Note that, for example, at the boundary between the first cover material 41 and the construction member main body 21, the second cover material 42 may be damaged due to air extruded from the first cover material 41 forming bubbles. In this case, the defect may be repaired by overcoating the second cover material 42.

[0059] Here, the method of applying the second covering material 42 or the method of dipping the second covering material 42 is arbitrary. However, in the embodiment, based on the test results of the third covering material performance confirmation test and the film thickness test described later, when the surface roughness of the construction member 20 is equal to or greater than a threshold value (for example, 3.1 or the like), the number of times of dipping or applying the second covering material 42 to the construction member 20 is set to 2 or more times. When the surface roughness of the construction member 20 is less than the threshold value, the number of times of dipping or applying the second covering material 42 to the construction member 20 is set to 3 or more times. Thereby, the second covering material 42 with a predetermined film thickness (specifically, a film thickness of 157 μm or more from the test results of the film thickness test described later) can be effectively attached according to the surface roughness of the construction member 20, and the attachability of the second covering material 42 can be improved.

[0060] However, it is not limited to this. For example, based on the test results of the second covering material performance confirmation test described later, as shown in FIG. 6, a part of the first non-adhering portion 23a and the entire each second non-adhering portion 23b may be attached so as to be covered with the second covering material 42. Thereby, while ensuring the function of the second covering material 42, the amount of use of the second covering material 42 can be reduced, and the manufacturing cost of the second covering material 42 can be effectively reduced.

[0061] (Method for removing cement hardened body - Removal step) Next, the removal step will be described.

[0062] The removal step is a step of removing the cement hardened body 30 attached to the construction member 20 by dipping the construction member 20 covered with the plurality of covering materials 40 in the acidic immersion liquid AS after the covering step.

[0063] Specifically, as shown in FIG. 7, first, the construction member 20 covered with a plurality of cover materials 40 and to which the cement hardened body 30 is attached is put into a container 50 containing an acidic immersion liquid AS. Next, the put construction member 20 is immersed in the acidic immersion liquid AS for a predetermined period (for example, about one to two weeks). Subsequently, after taking out the immersed construction member 20 from the container 50, the cement hardened body 30 is removed by spraying washing water onto the cement hardened body 30 or scraping off the cement hardened body 30 with an instrument such as a brush or by hand.

[0064] Here, regarding the cause of the discoloration of the construction member 20 when the construction member 20 not covered with a plurality of cover materials 40 is immersed in the acidic immersion liquid AS, the following is presumed. That is, regarding the surface film 22 of the construction member 20, when various components (RO2 component, R2O3 component, and RO, R2O components) that form the skeleton of the glaze are blended and fired in a well-balanced manner, a surface film 22 having acid resistance is formed. However, regarding a surface film (hereinafter referred to as "old surface film") formed using pre-modern formulation techniques and firing techniques, some components of the glaze (for example, Al component, Ca component, etc.) may remain as they are without reacting during the firing of the glaze. As a result, when the construction member 20 including the old surface film is immersed in the acidic immersion liquid AS, the remaining components elute from the old surface film, causing porosification (formation of pores) in a part of the old surface film (specifically, the surface layer part of the old surface film). Thus, when light is applied to the immersed old surface film, the old surface film appears white due to diffuse reflection of light at the porosified part of the old surface film. Therefore, this is presumed to be the cause of the discoloration of the construction member 20.

[0065] Also, the amount of the acidic immersion liquid AS stored in the container 50 is arbitrary as long as at least a part of the cement hardened body 30 can be immersed. However, in the embodiment, as shown in FIG. 7, it may be set to an amount such that both at least one or more construction members 20 and the cement hardened body 30 are completely immersed. However, it is not limited to this. For example, it may be set to an amount such that the construction member 20 is not immersed in the acidic immersion liquid AS.

[0066] Also, regarding the type of acid contained in the acidic immersion liquid AS, it can be arbitrary as long as it can react with at least a part of the components of the cement hardened body 30 to dissolve the cement hardened body 30. For example, hydrochloric acid, nitric acid, sulfuric acid, citric acid, hydroiodic acid, perchloric acid, hydrobromic acid, chloric acid, bromic acid, iodic acid, perbromic acid, metaperiodic acid, permanganic acid, thiocyanic acid, aqua regia, malic acid, lactic acid, glycolic acid, oxalic acid, malonic acid, succinic acid, phthalic acid, acetic acid, formic acid, tartaric acid, benzoic acid, propionic acid, butyric acid, valeric acid, etc. can be used.

[0067] (Method for removing cement hardened body - removal step) Next, the removal step will be described.

[0068] The removal step is a step of removing a plurality of cover materials 40 from the non - adhering surface 23 after the removal process.

[0069] Specifically, by using a known removal tool (as an example, a cutter, etc.) to peel the second cover material 42 from the non - adhering surface 23, the first cover material 41 and the second cover material 42 are removed simultaneously.

[0070] However, it is not limited to this. For example, after peeling the second cover material 42 from the non - adhering surface 23 or the first cover material 41 using a known removal tool, and then peeling the first cover material 41 from the non - adhering surface 23, the first cover material 41 and the second cover material 42 may be removed sequentially.

[0071] (Method for removing cement hardened body - immersion step) Subsequently, the immersion step will be described.

[0072] The immersion step is a step of immersing the construction member 20 from which a plurality of cover materials 40 have been removed in water after the removal step.

[0073] Specifically, first, the construction member 20 with the plurality of cover materials 40 removed is put into a container (not shown) filled with water. Then, the put-in construction member 20 is immersed in water for a predetermined period (for example, several hours, etc.), and then the immersed construction member 20 is taken out of the container.

[0074] Through such an immersion process, the components of the acidic immersion liquid AS attached to the put-in construction member 20 can be removed, and the discoloration of the construction member 20 can be suppressed.

[0075] By the above removal method, the discoloration of the construction member 20 can be suppressed by the first cover material 41 and the second cover material 42, and the reusability of the construction member 20 can be enhanced. In addition, the first cover material 41 can be easily attached to and detached from the construction member 20, and the covering process and the removal process can be efficiently performed.

[0076] (Test Results) Next, various test results obtained by the applicant of this application will be described. Here, the test results of the first cover material performance confirmation test to the fourth cover material performance confirmation test, and the film thickness confirmation test will be described.

[0077] (Test Results - First Cover Material Performance Confirmation Test - Overview) First, the overview of the first cover material performance confirmation test will be described. FIG. 8 is a diagram showing the details of the test piece of the first cover material performance confirmation test. FIG. 9 is a diagram showing the details of the construction member 20.

[0078] The first cover material performance confirmation test is a test for confirming the performance of the cover material 40 composed of various materials.

[0079] The test method of this first cover material performance confirmation test is arbitrary, but it is as follows. That is, first, after attaching the cover material 40 to the construction member 20 of each test piece, each test piece is put into a container 50 filled with an acidic immersion liquid AS (1 mol / L hydrochloric acid) and immersed for one week. Then, when one week has passed since the immersion, visual observation of each test piece is performed before and after removing the cover material 40 from each test piece.

[0080] In addition, regarding the test specimens used in the first cover material performance confirmation test (specifically, the test specimens configured with the structure shown in FIG. 3), as shown in FIG. 8, they are divided into test specimens A1 to A5.

[0081] Among these, test specimen A1 is a test specimen with construction member 20 = first tile material, first cover material 41 = none, and second cover material 42 = cloth adhesive tape (7 specimens were made). Also, test specimen A2 is a test specimen with construction member 20 = first tile material, first cover material 41 = none, and second cover material 42 = polyethylene tape (7 specimens were made). Also, test specimen A3 is a test specimen with construction member 20 = first tile material, first cover material 41 = none, and second cover material 42 = synthetic rubber-based coating material (7 specimens were made). Also, test specimen A4 is a test specimen with construction member 20 = first tile material, first cover material 41 = cloth adhesive tape, and second cover material 42 = synthetic rubber-based coating material (7 specimens were made). Also, test specimen A5 is a test specimen with construction member 20 = first tile material, first cover material 41 = polyethylene tape, and second cover material 42 = synthetic rubber-based coating material (3 specimens were made).

[0082] In addition, regarding the details of the configuration of the first tile material, as shown in FIG. 9, it is as follows. That is, regarding the dimensions of the first tile material, it is set to the size obtained by dividing a tile material with a length of 200 mm × width of 200 mm × thickness of 15 mm into six parts. Also, regarding the shape of the front main surface of the first tile material (the surface of the tile material with the largest area and located on the front side), it is set to be smooth. Also, regarding the shape of the surfaces other than the main surface of the first tile material, it is set to be uneven. Also, the front main surface of the first tile material is glazed.

[0083] (Test Results - First Cover Material Performance Confirmation Test - Details of Test Results) Next, the details of the test results of the first cover material performance confirmation test will be described. FIG. 10 is a diagram showing the test results of the first cover material performance confirmation test.

[0084] Here, the "adhesion retention" in FIG. 10 means the performance of being able to maintain sufficient adhesion between the cover material 40 and the construction member 20 during the period when the test piece is immersed in the acidic immersion liquid AS. Also, the "peelability" in FIG. 10 means the performance of being able to peel the cover material 40 from the construction member 20 after the test piece is immersed in the acidic immersion liquid AS. Further, for example, "7 / 7" in FIG. 10 indicates that 7 out of 7 bodies are unqualified regarding adhesion retention or peelability.

[0085] As shown in FIG. 10, first, regarding the cover materials 40 of the test pieces A1 and A2, although the adhesion retention is low (in particular, it was confirmed that the end part of the cover material 40 peeled off from the first tile material and acidic immersion liquid AS penetrated through the gap), it was confirmed that the peelability is high. Also, regarding the cover material 40 of the test piece A3, it was confirmed that both the adhesion retention and the peelability are low (in particular, it was confirmed that it is difficult to remove the part of the cover material 40 attached to the surface other than the main surface of the first tile material). Also, regarding the cover materials 40 of the test pieces A4 and A5, although the adhesion retention is high (in particular, it was confirmed that the end part of the cover material 40 did not peel off from the first tile material), it was confirmed that the peelability is low.

[0086] From the above, for the cover material 40 that is only tape or only coating material, although it is difficult to enhance the adhesion retention and the peelability, it was confirmed that for the cover material 40 combined with a plurality of members, there is a possibility of enhancing the adhesion retention and the peelability by devising the configuration.

[0087] (Test Results - Second Cover Material Performance Confirmation Test - Overview) Next, the overview of the second cover material performance confirmation test will be described. FIG. 11 is a diagram showing the details of the test piece of the second cover material performance confirmation test. FIG. 12 is a diagram showing the details of the construction member 20.

[0088] The second cover material performance confirmation test is a test for confirming the performance of the cover material 40 composed of various materials.

[0089] The test method for this second cover material performance confirmation test is optional, but it is as follows. That is, first, using a known color difference meter, color measurement is performed on each test body to which the cover material 40 is not attached. Next, after attaching the cover material 40 to the construction member 20 of each test body, each test body is put into a container 50 containing an acidic immersion liquid AS (1 mol / L hydrochloric acid) and immersed for one week. Then, when one week has passed since the above immersion, visual observation of each test body is performed before and after removing the cover material 40 from each test body. And after performing the above color measurement on each test body again, a color difference ΔE is calculated based on the color measurement before immersion and the color measurement after immersion using a known method.

[0090] Also, regarding the test bodies used in the second cover material performance confirmation test (specifically, the test bodies configured with the structure shown in FIG. 6), as shown in FIG. 11, they are divided into test bodies B1 to B9.

[0091] Among these, the test specimen B1 is a test specimen in which the construction member 20 = the second tile material, the first cover material 41 = none, and the second cover material 42 = none. Also, the test specimen B2 is a test specimen in which the construction member 20 = the second tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = none. Also, the test specimen B3 is a test specimen in which the construction member 20 = the second tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = resin-based adhesive. Also, the test specimen B4 is a test specimen in which the construction member 20 = the second tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = silicone seal. Also, the test specimen B5 is a test specimen in which the construction member 20 = the second tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = water-based strippable. Also, the test specimen B6 is a test specimen in which the construction member 20 = the second tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = putty for air conditioner. Also, the test specimen B7 is a test specimen in which the construction member 20 = the second tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, the test specimen B8 is a test specimen in which the construction member 20 = the second tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = spray coating material (specifically, a spray coating material that is easy to peel off). Also, the test specimen B9 is a test specimen in which the construction member 20 = the second tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = tape primer.

[0092] Also, regarding the details of the configuration of the second tile material, as shown in FIG. 12, it is as follows. That is, regarding the dimensions of the second tile material, they are set to 60 mm in length × 107 mm in width × 15 mm in thickness. Also, regarding the shape of the front main surface of the second tile material, it is set to a relatively small uneven shape. Also, regarding the shape of the surfaces other than the main surface of the second tile material, it is set to a relatively small uneven shape. Also, the front main surface of the second tile material is glazed.

[0093] (Test Results - Second Cover Material Performance Confirmation Test - Details of Test Results) Next, the details of the test results of the second cover material performance confirmation test will be described. FIG. 13 is a diagram showing the test results of the second cover material performance confirmation test.

[0094] Here, the "workability" in FIG. 13 means the performance of being able to attach the cover material 40 to the construction member 20. Also, the "waterproof property of the first cover material 41" in FIG. 13 means the performance of being able to block the intrusion of the acidic immersion liquid AS from the first cover material 41 into the construction member 20 during the period when the test piece is immersed in the acidic immersion liquid AS. Further, the "waterproof property of the second cover material 42" in FIG. 13 means the performance of being able to block the intrusion of the acidic immersion liquid AS from the second cover material 42 into the construction member 20 or the first cover material 41 during the period when the test piece is immersed in the acidic immersion liquid AS. Also, "◎" in FIG. 13 indicates very good, "〇" in FIG. 13 indicates good, "△" in FIG. 13 indicates it may or may not be acceptable, and "×" in FIG. 13 indicates not good.

[0095] As shown in FIG. 13, first, for the cover materials 40 of the test pieces B1, B2, B8, and B9, although at least one of workability, waterproof property, or peelability is low, it was confirmed that for the cover materials 40 of the test pieces B3 to B7, the workability, waterproof property, and peelability are high. Also, among the cover materials 40 of the test pieces B3 to B7, it was confirmed that for the cover materials 40 of the test pieces B3 and B7, the color difference is less than 1.

[0096] From the above, the effectiveness of configuring the first cover material 41 with a cloth adhesive tape and the second cover material 42 with paraffin, a resin-based adhesive, or a silicone seal was confirmed.

[0097] (Test Results - Third Cover Material Performance Confirmation Test - Overview) Next, the overview of the third cover material performance confirmation test will be described. FIG. 14 is a diagram showing the details of the test pieces of the third cover material performance confirmation test. FIG. 15 is a diagram showing the details of various construction members 20.

[0098] The third cover material performance confirmation test is a test for confirming the performance of various second cover materials 42.

[0099] The test method for this third cover material performance confirmation test is optional, but it is as follows. That is, first, after attaching the first cover material 41 and the second cover material 42 to the construction member 20 of each test piece, each test piece is put into a container 50 containing an acidic immersion liquid AS (1 mol / L hydrochloric acid) and immersed for two weeks. Then, when two weeks have passed since the above immersion, visual observation of each test piece is performed before and after removing the first cover material 41 and the second cover material 42 from each test piece. And after removing the first cover material 41 and the second cover material 42 from each test piece, the presence or absence of an acid reaction of the construction member 20 of each test piece is confirmed using pH test paper.

[0100] Also, regarding the test pieces used in the third cover material performance confirmation test (specifically, the test pieces configured with the structure shown in FIG. 3), as shown in FIG. 14, they are divided into test pieces C1 to C9.

[0101] Among these, test piece C1 (12 pieces are made), test piece C2 (4 pieces are made), and test piece C3 (4 pieces are made) are test pieces with the construction member 20 = the third tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, test piece C4 (12 pieces are made), test piece C5 (4 pieces are made), and test piece C6 (4 pieces are made) are test pieces with the construction member 20 = the fourth tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, test piece C7 (12 pieces are made), test piece C8 (4 pieces are made), and test piece C9 (4 pieces are made) are test pieces with the construction member 20 = the fifth tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, the number of coating times of the second cover material 42 for test piece C1, test piece C4, and test piece C7 is 1 time, the number of coating times of the second cover material 42 for test piece C2, test piece C5, and test piece C8 is 2 times, and the number of coating times of the second cover material 42 for test piece C3, test piece C6, and test piece C9 is 4 times.

[0102] Regarding the details of the configurations of the third to fifth tile materials, as shown in Fig. 15, they are as follows. That is, for the classification of water absorption rate, the third tile material = Class I, the fourth tile material = Class II, and the fifth tile material = Class III. Also, regarding the presence or absence of glazing on the front main surface, the third tile material = with glazing, the fourth tile material = with glazing, and the fifth tile material = without glazing. Also, regarding the shape of the front main surface, the third tile material = smooth, the fourth tile material = relatively small unevenness, and the fifth tile material = relatively large unevenness. Also, regarding the thickness, the third tile material = 9 mm, the fourth tile material = 10 mm, and the fifth tile material = 14 mm. Also, regarding the surface roughness of the front main surface, the third tile material = 3.1 μm, the fourth tile material = 8.6 μm, and the fifth tile material = 111.0 μm. Also, regarding the surface roughness of the surfaces other than the main surface, the third tile material = 7.9 μm, the fourth tile material = 19.6 μm, and the fifth tile material = 11.6 μm.

[0103] (Test Results - Performance Confirmation Test of the Third Cover Material - Details of Test Results) Next, the details of the test results of the performance confirmation test of the third cover material will be described. Fig. 16 is a diagram showing the test results of the performance confirmation test of the third cover material.

[0104] Here, "success" in Fig. 16 indicates that after the immersion of each test piece, the first cover material 41 has not peeled off from the construction member 20, and there is no acid reaction in the construction member 20 of each test piece. Also, "peeling" in Fig. 16 indicates that after the immersion of each test piece, the first cover material 41 has peeled off from the construction member 20. Also, "acid intrusion" in Fig. 16 indicates that after the immersion of each test piece, there is an acid reaction in the construction member 20 of each test piece. Also, "peeling + acid intrusion" in Fig. 16 indicates that after the immersion of each test piece, the first cover material 41 has peeled off from the construction member 20, and there is an acid reaction in the construction member 20 of each test piece.

[0105] As shown in Fig. 16, first, for test specimens C1, C2, C4, and C5, the number of times the first cover material 41 peeled off from the construction member 20 and the number of times the acid reaction occurred in the construction member 20 of each test specimen were large. On the other hand, for test specimens C3, C6 to C9, the number of times the first cover material 41 peeled off from the construction member 20 and the number of times the acid reaction occurred in the construction member 20 of each test specimen were small. From this, it was confirmed that the smaller the surface roughness of the front main surface of the construction member 20 and the thinner the thickness of the construction member 20, the easier it was for the first cover material 41 to peel off and for the acid reaction to occur in the construction member 20.

[0106] Also, for test specimens C5, C6, C8, and C9, the first cover material 41 did not peel off from the construction member 20, and the number of times there was no acid reaction in the construction member 20 of each test specimen was large. From this, when the surface roughness of the construction member 20 is less than 3.1, the number of times the second cover material 42 is applied is set to 3 or more, and when the surface roughness of the construction member 20 is 3.1 or more, the number of times the second cover material 42 is applied is set to 2 or more. It was confirmed that the peeling of the first cover material 41 of each test specimen and the acid reaction in the construction member 20 can be suppressed.

[0107] Also, for test specimens C4 to C6, although the first cover material 41 did not peel off from the construction member 20, since there was an acid reaction in the construction member 20 of each test specimen, it is presumed that the acidic immersion liquid AS penetrated from the back main surface of the construction member 20 (the main surface with the largest area among the surfaces of the construction member 20 and located on the back side) or through the protective layer on the front main surface. However, when the discoloration state of the construction member 20 of test specimens C4 to C6 was confirmed, since the progress of discoloration was slow, it is considered that even if the acidic immersion liquid AS penetrates from the back main surface to the front main surface of the construction member 20, the discoloration of the construction member 20 due to the penetration can be suppressed.

[0108] From the above, in the case where the first cover material 41 is composed of cloth adhesive tape and the second cover material 42 is composed of paraffin, the effectiveness of applying the second cover material 42 with the number of application times according to the surface roughness of the construction member 20 was confirmed.

[0109] (Test Results - Fourth Cover Material Performance Confirmation Test - Overview) Next, an overview of the fourth cover material performance confirmation test will be described. FIG. 17 is a diagram showing the details of the test specimen of the fourth cover material performance confirmation test. FIG. 18 is a diagram showing the details of various construction members 20.

[0110] The fourth cover material performance confirmation test is a test for confirming the performance of the first cover material 41 and the second cover material 42 when using an attachment method different from the attachment method of the second cover material 42 in the third cover material performance confirmation test.

[0111] The test method of this fourth cover material performance confirmation test shall be the same as the test method of the third cover material performance confirmation test.

[0112] Also, regarding the test specimens used in the fourth cover material performance confirmation test (specifically, the test specimens configured with the structure shown in FIG. 4), as shown in FIG. 17, they are divided into test specimens D1 to D5.

[0113] Among these, the test specimens D1 (10 specimens were made) are test specimens with the construction member 20 = the 6th tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, the test specimens D2 (10 specimens were made) are test specimens with the construction member 20 = the 7th tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, the test specimens D3 (10 specimens were made) are test specimens with the construction member 20 = the 8th tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, the test specimens D4 (10 specimens were made) are test specimens with the construction member 20 = the 9th tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, the test specimens D5 (10 specimens were made) are test specimens with the construction member 20 = the 10th tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, regarding the attachment method of the second cover material 42 of these test specimens, the first non-adhesive portion 23a was immersed in paraffin twice, and paraffin was applied once to the entire surface of the construction member 20.

[0114] Also, regarding the details of the composition of the 6th to 10th tile materials manufactured by different manufacturers, as shown in Fig. 18, it is as follows. That is, regarding the thickness, the 6th tile material = 9 mm, the 7th tile material = 5 mm, the 8th tile material = 9 mm, the 9th tile material = 5 mm, and the 10th tile material = 9 mm are set. Also, regarding the presence or absence of glazing on the front main surface, the 6th tile material = with glazing, the 7th tile material = with glazing, the 8th tile material = with glazing, the 9th tile material = without glazing, and the 10th tile material = with glazing are set. Also, regarding the size of the front main surface, the 6th tile material = relatively small, the 7th tile material = relatively small, the 8th tile material = relatively large, the 9th tile material = relatively large, and the 10th tile material = relatively small are set. Also, regarding the shape of the front main surface, the 6th tile material = smooth, the 7th tile material = smooth, the 8th tile material = smooth, the 9th tile material = uneven, and the 10th tile material = smooth are set. Also, regarding the water permeability, the 6th tile material = relatively low, the 7th tile material = relatively low, the 8th tile material = relatively low, the 9th tile material = relatively high, and the 10th tile material = relatively low are set.

[0115] (Test Results - Performance Verification Test of the Fourth Cover Material - Details of Test Results) Next, the details of the test results of the performance verification test of the fourth cover material will be described. Fig. 19 is a diagram showing the test results of the performance verification test of the fourth cover material.

[0116] As shown in Fig. 19, first, for test specimens D1 to D3 and D5, the first cover material 41 did not peel off from the construction member 20, and there were many cases where there was no reaction of acid in the construction member 20 of each test specimen. Since the probability of being judged as "successful" was 95%, it was confirmed that they had high adhesion retention and water stoppage performance, and it was also confirmed that the film thickness of the second cover material 42 was sufficient. Also, for test specimens D1 to D5, since only one case was found where the first cover material 41 peeled off from the construction member 20, it was confirmed that the configuration in Fig. 4 had sufficient adhesion retention.

[0117] From the above, the effectiveness of covering the construction member 20 with the first cover material 41 and the second cover material 42 as shown in Fig. 4 was confirmed.

[0118] (Test Results - Film Thickness Test - Overview) Next, the overview of the film thickness test will be described. Fig. 20 is a diagram showing the details of the test specimens of the film thickness test.

[0119] The film thickness test is a test for confirming the size of the film thickness of the second cover material 42 according to the number of dipping times or coating times.

[0120] Regarding the test method of this film thickness test, after attaching the first cover material 41 to the construction member 20 of each test specimen, the second cover material 42 is applied a total of 4 times by brush or dipping, and the film thickness of the second cover material 42 for each coating time is measured with a microscope (specifically, the film thicknesses at 10 locations of the second cover material 42 are measured, and the average value of the measured film thicknesses is shown in Fig. 21 described later).

[0121] Also, regarding the test specimens used in the film thickness test (specifically, the test specimens configured with the structure in Fig. 3), as shown in Fig. 20, they are divided into test specimens E1 to E6.

[0122] Among these, the test specimens E1 and E4 are test specimens with the construction member 20 = the third tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, the test specimens E2 and E5 are test specimens with the construction member 20 = the fourth tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, the test specimens E3 and E6 are test specimens with the construction member 20 = the fifth tile material, the first cover material 41 = cloth adhesive tape, and the second cover material 42 = paraffin. Also, for the test specimens E1 to E3, the attachment method of the second cover material 42 = application with a brush, and for the test specimens E4 to E6, the attachment method of the second cover material 42 = immersion in an acidic immersion liquid.

[0123] (Test Results - Film Thickness Test - Details of Test Results) Next, the details of the test results of the film thickness test will be described. FIG. 21 is a diagram showing the test results of the film thickness test.

[0124] As shown in FIG. 21, first, for the test specimens E1 to E6, it was confirmed that as the number of application times or immersion times increased, the film thickness of the second cover material 42 increased. Also, it was confirmed that the film thickness of the second cover material 42 with the number of application times or immersion times = 3 times might be the same as the film thickness of the second cover material 42 with the number of application times or immersion times = 4 times. Also, for the test specimens E1 to E3, since the test specimen E3 had a larger film thickness of the second cover material 42 than the test specimens E1 and E2, it was confirmed that the rougher the surface roughness of the surface of the table, the more efficiently the application with a brush could be performed. Also, based on the third cover material performance confirmation test, it was confirmed that the film thickness required to have a predetermined water-stopping property was 157 μm or more (note that "157 μm" is the minimum film thickness among the film thicknesses at 10 locations in the second application for the test specimen E2). Also, for the test specimens E4 to E6, since the test specimen E4 had a larger film thickness of the second cover material 42 than the test specimens E5 and E6, it was confirmed that the smoother the surface roughness of the surface of the table, the more efficiently the immersion in the acidic immersion liquid AS could be performed.

[0125] From the above, in the case where the first cover material 41 is composed of a cloth adhesive tape and the second cover material 42 is composed of paraffin, the effectiveness of attaching the second cover material 42 with the number of coating times or dipping times according to the surface roughness of the construction member 20 was further confirmed.

[0126] (Effects of the Embodiment) As described above, according to the embodiment, a plurality of cover materials 40 are configured to block the acidic immersion liquid AS, and the first cover material 41 is configured to be detachable from and attachable to the non - adhering surface 23, and the second cover material 42 is provided outside the first cover material 41. The second cover material 42 is configured to block the acidic immersion liquid AS and is configured to maintain the adhesion between the second cover material 42 and the non - adhering surface 23 or the first cover material 41. Therefore, the discoloration of the construction member 20 can be suppressed by the first cover material 41 and the second cover material 42, and the reusability of the construction member 20 can be enhanced. In addition, the first cover material 41 can be easily attached to and detached from the construction member 20, and the covering process and the removing process can be efficiently performed.

[0127] Further, in the covering process, the entire first non - adhering portion 23a, which is at least the portion of the non - adhering surface 23 opposite to the adhering surface 24 where the cement hardened body 30 is adhered, and a part of the second non - adhering portion 23b, which is the portion between the first non - adhering portion 23a and the adhering surface 24, are covered with the first cover material 41. At least a part of the first non - adhering portion 23a and the entire second non - adhering portion 23b of the non - adhering surface 23 are covered with the second cover material 42. Therefore, while ensuring the functions of the first cover material 41 and the second cover material 42, the usage amounts of the first cover material 41 and the second cover material 42 can be reduced, and the manufacturing costs of the first cover material 41 and the second cover material 42 can be effectively reduced.

[0128] Further, since the first cover material 41 includes an adhesive tape, a cloth adhesive tape, a tape material having water - stopping properties, and / or a putty material, the first cover material 41 can be manufactured at a relatively low cost, and the manufacturing costs of the plurality of cover materials 40 can be reduced.

[0129] In addition, since the second cover material 42 contains a water-repellent coating material and / or an adhesive, the second cover material 42 can be manufactured at a relatively low cost, and the manufacturing cost of the plurality of cover materials 40 can be reduced.

[0130] Also, since the film thickness of the second cover material 42 is set to 157 μm or more, it becomes easier to ensure the function of the second cover material 42, and thus it becomes easier to ensure the quality of the plurality of cover materials 40.

[0131] [III] Modifications to the Embodiment As described above, the embodiments of the present invention have been described. However, the specific configurations and means of the present invention can be arbitrarily modified and improved within the scope of the technical idea of each invention described in the claims. Hereinafter, such modifications will be described.

[0132] (Regarding the problems to be solved and the effects of the invention) First, the problems to be solved by the invention and the effects of the invention are not limited to the above-described content. By the present invention, it is also possible to solve problems not described above or to exhibit effects not described above. Further, it may solve only some of the described problems or exhibit only some of the described effects.

[0133] (Regarding shape, numerical value, structure, and time series) Regarding the components exemplified in the embodiments and the drawings, with respect to the shape, numerical value, or the structure or time series correlation of a plurality of components, it can be arbitrarily modified and improved within the scope of the technical idea of the present invention.

[0134] (Regarding construction members) In the above embodiment, it has been described that the construction member 20 includes the surface film 22, but it is not limited thereto. For example, when the construction member main body 21 itself may change color by reacting with an acid immersion liquid, the surface film 22 may be omitted.

[0135] (Regarding cover materials) In the above embodiment, it was described that the plurality of cover materials 40 include one first cover material 41 and one second cover material 42, but it is not limited thereto. For example, it may include a plurality of first cover materials 41 and one second cover material 42 that are laminated. Alternatively, it may include one first cover material 41 and a plurality of second cover materials 42 that are laminated. Alternatively, it may include a plurality of first cover materials 41 and a plurality of second cover materials 42 that are laminated.

[0136] Also, in the above embodiment, it was described that the film thickness of the second cover material 42 is set to 157 μm or more, but it is not limited thereto. For example, when the first cover material 41 is formed of a material having high water-stopping properties, the film thickness of the second cover material 42 may be set to less than 157 μm.

[0137] (Regarding the method for removing the cement hardened body) In the above embodiment, it was described that the method for removing the cement hardened body 30 includes a preparation step and an immersion step, but it is not limited thereto. For example, when the construction member 20 and the cement hardened body 30 have already been removed from the housing body 10, the preparation step may be omitted. Alternatively, when the construction member main body 21 of the construction member 20 is not easily affected by the acidic immersion liquid AS, the immersion step may be omitted.

[0138] (Supplementary Note) The method for removing the cement hardened body of Supplementary Note 1 is a removal method for removing the cement hardened body adhering to a construction member from the construction member. Among the surfaces of the construction member, a covering step of covering the entire non-adhering surface where the cement hardened body is not adhered with a plurality of detachable cover materials; after the covering step, immersing the construction member covered with the plurality of cover materials in an acidic immersion liquid to remove the cement hardened body adhering to the construction member; and a removing step of removing the plurality of cover materials from the non-adhering surface after the removing step. The plurality of cover materials include a first cover material configured to be able to block the acidic immersion liquid and configured to be detachable from the non-adhering surface, and a second cover material provided outside the first cover material, the second cover material being configured to be able to block the acidic immersion liquid and configured to be able to maintain the adhesion between the second cover material and the non-adhering surface or the first cover material.

[0139] The method for removing the cement hardened body of Supplementary Note 2 is the method for removing the cement hardened body according to Supplementary Note 1. In the covering step, the entire first non-adhering portion, which is at least a portion of the non-adhering surface on the side opposite to the adhering surface where the cement hardened body is adhered, and a part of the second non-adhering portion, which is the portion between the first non-adhering portion and the adhering surface, are covered with the first cover material. Among the portions of the non-adhering surface, at least a part of the first non-adhering portion and the entire second non-adhering portion are covered with the second cover material.

[0140] The method for removing the cement hardened body of Supplementary Note 3 is the method for removing the cement hardened body according to Supplementary Note 1 or 2. The first cover material includes a tape material or / and a putty material having water-stopping properties.

[0141] The method for removing the cement hardened body of Supplementary Note 4 is the method for removing the cement hardened body according to any one of Supplementary Notes 1 to 3. The second cover material includes a water-repellent coating material or / and an adhesive.

[0142] The method for removing the cement hardened body in Supplementary Note 5 is such that in the method for removing the cement hardened body described in Supplementary Note 4, the film thickness of the second covering material is set to 157 μm or more.

[0143] (Effect of Supplementary Note) According to the method for removing the cement hardened body described in Supplementary Note 1, a plurality of covering materials are configured to be able to block an acidic immersion liquid, and a first covering material that is configured to be detachable from and attachable to a non-adhering surface, and a second covering material provided outside the first covering material, which is configured to be able to block an acidic immersion liquid and is configured to be able to maintain the adhesion between the second covering material and the non-adhering surface or the first covering material. Therefore, the discoloration of the construction member can be suppressed by the first covering material and the second covering material, and the reusability of the construction member can be enhanced. In addition, the first covering material can be easily attached to and detached from the construction member, and the covering process and the removing process can be efficiently performed.

[0144] According to the method for removing the cement hardened body described in Supplementary Note 2, in the covering process, the entire first non-adhering portion, which is at least the portion of the non-adhering surface on the side opposite to the adhering surface to which the cement hardened body is adhered, and a part of the second non-adhering portion, which is the portion between the first non-adhering portion and the adhering surface, are covered with the first covering material, and at least a part of the first non-adhering portion and the entire second non-adhering portion among the portions of the non-adhering surface are covered with the second covering material. Therefore, while ensuring the functions of the first covering material and the second covering material, the usage amounts of the first covering material and the second covering material can be reduced, and the manufacturing costs of the first covering material and the second covering material can be effectively reduced.

[0145] According to the method for removing the cement hardened body described in Supplementary Note 3, since the first covering material includes a tape material and / or a putty material having water-stopping properties, the first covering material can be manufactured at a relatively low cost, and the manufacturing costs of the plurality of covering materials can be reduced.

[0146] According to the method for removing the cement hardened body described in Supplementary Note 4, since the second covering material includes a water-repellent coating material and / or an adhesive, the second covering material can be manufactured at a relatively low cost, and the manufacturing costs of the plurality of covering materials can be reduced.

[0147] According to the method for removing the cement hardened body described in Supplementary Note 5, since the film thickness of the second covering material is set to 157 μm or more, it becomes easier to ensure the function of the second covering material, and thus it becomes easier to ensure the quality of the plurality of covering materials.

Explanation of Signs

[0148] 1 Body 10 Body main body 20 Construction member 21 Construction member main body 22 Surface film 23 Non-adhering surface 23a First non-adhering portion 23b Second non-adhering portion 24 Adhering surface 30 Cement hardened body 40 Covering material 41 First covering material 42 Second covering material 50 Container AS Acidic immersion liquid

Claims

1. A removal method for removing a cement hardened body adhering to a construction material from the construction material, comprising: a covering step of covering the entire non-adhering surface of the surface of the construction material where the cement hardened body is not adhered with a plurality of detachable cover materials; a removal step of removing the cement hardened body adhering to the construction material by immersing the construction material covered with the plurality of cover materials in an acidic immersion liquid after the covering step; a removal step of removing the plurality of cover materials from the non-adhering surface after the removal step, wherein the plurality of cover materials include: a first cover material configured to be able to block the acidic immersion liquid and configured to be detachable from the non-adhering surface; a second cover material provided outside the first cover material, the second cover material being configured to be able to block the acidic immersion liquid and configured to be able to maintain the adhesion between the second cover material and the non-adhering surface or the first cover material; in the covering step, covering the entire first non-adhering portion, which is at least a portion of the non-adhering surface on the side opposite to the adhering surface where the cement hardened body is adhered, and a part of the second non-adhering portion, which is a portion between the first non-adhering portion and the adhering surface, with the first cover material; covering at least a part of the first non-adhering portion and the entire second non-adhering portion of the non-adhering surface with the second cover material; A method for removing a cement hardened body.

2. The first cover material includes a tape material and / or a putty material having water-stopping properties. The method for removing a cement hardened body according to Claim 1.

3. The second cover material includes a coating material and / or an adhesive having water-repellent properties. The method for removing a cement hardened body according to Claim 1 or 2.

4. The film thickness of the second cover material is 157 μm or more. The method for removing a cement hardened body according to Claim 3.

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