JP5646375B2 - Method for producing buried metal fitting and lightweight cellular concrete panel - Google Patents

Description

  The present invention relates to a buried metal fitting and a method for producing a lightweight cellular concrete panel.

  In lightweight cellular concrete panels (ALC panels) with anchor metal fittings that are attached to the structural frame of the building, the anchor metal parts are subjected to rust prevention treatment to prevent the occurrence of rust, and then applied to the reinforcing steel bars. It is fixed by welding or the like and embedded in the ALC panel.

  As such a rust-proofing method for anchor metal fittings, for example, Patent Document 1 proposes to perform nickel plating (see Patent Document 1).

JP 2003-291128 A

  The rust prevention treatment method by nickel plating proposed in Patent Document 1 is expensive because the material used for the rust prevention treatment is expensive and the equipment for the rust prevention treatment is costly. There is a problem.

  As a cost-effective method compared to nickel plating, an antirust treatment method for anchor fittings by cationic electrodeposition coating of epoxy resin was examined. However, in the ALC panel in which the metal fitting subjected to the rust prevention treatment is embedded, a fine crack may occur in the rust prevention film mainly composed of an epoxy resin by the autoclave. In the anchor pull-out test of the ALC panel, The antirust coating peels off (breaks), and sufficient pullout strength may not be obtained.

  The present invention has been completed based on the above circumstances, and an object thereof is to provide an ALC panel having a sufficient anchor pull-out strength while being low in cost.

  In the ALC panel provided with a metal fitting subjected to a rust prevention treatment by a method of applying a cation electrodeposition coating material mainly composed of an epoxy resin, the following may be considered as a cause of peeling of the rust prevention film.

  When manufacturing ALC panels with embedded anchor metal fittings, the anchor metal fittings are rust-proofed and then welded to the reinforcing bars, and the reinforcing bars with the anti-rust-treated metal fittings are placed inside the formwork After the ALC raw material slurry is cast and cured, a cutting process and a curing process in an autoclave at about 180 ° C. are performed.

  Here, it is considered that when the temperature becomes high during the autoclave curing, the epoxy resin constituting the rust preventive film deteriorates and cracks are likely to occur in the rust preventive film.

  Therefore, as a result of further studies, an ALC panel using a metal fitting formed with a rust-preventing film containing styrene-acrylic resin as a main component as a buried metal fitting has a sufficient anchor pull-out strength while being low in cost. I got the knowledge. The present invention is based on such novel findings.

  That is, the present invention is an embedded metal fitting embedded in a lightweight cellular concrete panel and having a rust preventive film made of styrene-acrylic resin formed on the surface thereof.

  Moreover, this invention passed through the 1st rust prevention process process which forms the rust prevention film which consists of a styrene-acrylic resin in the surface of the embedment metal fitting embedded in a lightweight cellular concrete panel, and the said 1st rust prevention process process. A fixing step of fixing the embedded metal fitting to the reinforcing steel bar, a surface of the reinforcing steel bar after the fixing step, a second resin rust preventive layer containing a styrene-acrylic resin on the surface of the embedded metal fitting, and a cement type containing cement Production of semi-cured body by producing a semi-cured body by placing a raw material slurry in a mold having a second rust-preventing treatment step for forming a rust-preventing layer and a reinforcing bar that has undergone the second rust-preventing treatment step. A method for producing a lightweight cellular concrete panel, comprising: a step, and an autoclave curing step of curing the semi-cured material obtained through the semi-cured material preparation step.

  In the present invention, the styrene-acrylic resin used as the material for the anticorrosive film is an inexpensive material compared to the material used for nickel plating. Moreover, in the present invention, in order to form a rust preventive film on the surface of the embedded metal fitting, it is possible to produce the embedded metal fitting and the ALC at a low cost without requiring a large-sized apparatus as compared with the case of performing electrodeposition coating. .

  Further, the ALC panel in which the embedded metal fitting of the present invention is embedded has excellent anchor pull-out strength as shown in the examples described later, and the rust preventive film peels (breaks) during the anchor pull-out test. Does not occur. As a result, according to the present invention, it is possible to provide an ALC panel having a sufficient anchor pull-out strength at a low cost.

  In addition, it is thought that the effect that the present invention can provide an ALC panel having sufficient anchor pull-out strength is due to the fact that the styrene-acrylic resin contained in the rust preventive film is not deteriorated by the autoclave curing.

  In the present invention, when the thickness of the rust preventive film is 20 μm or more and 50 μm or less, the rust preventive film can be uniformly formed on the surface of the embedded metal fitting, and can be easily joined when the embedded metal fitting is fixed to the reinforcing steel bar by welding. Therefore, it is preferable. Moreover, when the thickness of the rust preventive film is 50 μm or less, it is also preferable in that the smoke generation during welding is reduced and the operation becomes easy.

  According to the present invention, it is possible to provide an ALC panel having a sufficient anchor pull-out strength while reducing the cost required for an anticorrosive agent and equipment for an anchor.

The figure which showed the embedding metal fitting of Embodiment 1 embedded in the ALC panel from the upper surface. Side view of buried bracket Bottom view of buried bracket The figure which showed the reinforcement reinforcement arranged in the ALC panel from the upper surface The perspective view which shows the outline | summary of the anchor pull-out test using the embedded metal fitting of Embodiment 1.

<Embodiment 1>
The embedded metal fitting 10 of the first embodiment embodying the present invention will be described with reference to FIGS. 1 to 5. In the present embodiment, the embedded metal fitting 10 having a substantially U-shaped side view as illustrated in FIGS. 1 to 3 and 5 will be described as an example, but the shape of the embedded metal fitting 10 of the present invention is not limited thereto. In the following description, the upper side in FIG.

  As shown in FIG. 1, the embedded metal fitting 10 is a metal (for example, iron) member embedded in the ALC panel 1 while being fixed to the reinforcing reinforcing bar 2, and the ALC panel 1 is a casing (not shown). It is a member for attaching to. In the ALC panel 1, the reinforcing reinforcing bars 2 to which the embedded metal fittings 10 are attached are arranged along the short side direction with the reinforcing reinforcing bars 2A arranged along the longitudinal direction, as shown in FIGS. The reinforcing reinforcing bars 2B are arranged to form a lattice set.

  As shown in FIG. 2, two mounting pieces 11 are formed on the upper surface 10A of the embedded metal fitting 10 so as to sandwich the reinforcing reinforcing bars 2 arranged along the longitudinal direction between the upper surface 10A of the embedded metal fitting 10 and the upper surface 10A. Yes. The two attachment pieces 11, 11 of the embedded metal fitting 10 are attached so as to sandwich a predetermined portion of the reinforcing rebar 2 and are fixed to the reinforcing rebar 2 by a method such as welding.

  As shown in FIGS. 2 and 3, a cylindrical body 12 arranged in the vertical direction (the thickness direction of the ALC panel 1) is fixed to the side surface 10 </ b> B of the embedded metal fitting 10. Although not shown in detail on the lower end (nut portion) 12A side of the cylindrical body 12, a female screw is formed and is attached to the housing.

  On the surface of the embedded metal fitting 10 of the present invention, a rust preventive film (not shown) made of styrene-acrylic resin is formed. In the present invention, when the thickness of the rust preventive film is 20 μm or more and 50 μm or less, the rust preventive film can be uniformly formed on the surface of the embedded metal fitting 10 and when the embedded metal fitting 10 is fixed to the reinforcing reinforcing bar 2 by welding. It is preferable because it can be easily joined. Moreover, when the thickness of the rust preventive film is 50 μm or less, it is also preferable in that the smoke generation during welding is reduced and the operation becomes easy. When the thickness of the rust preventive film is less than 20 μm, the thickness of the rust preventive film may not be uniform or sufficient rust preventive performance may not be obtained. When the thickness of the rust preventive film exceeds 50 μm, the reinforcing reinforcing bar 2 When welding, it may become difficult to join, or the amount of smoke generated during welding may increase, making it difficult to perform the work.

  Examples of the styrene-acrylic resin constituting the rust preventive film include those containing styrene as a constituent unit in a proportion of 10% by mass to 50% by mass with respect to the total mass of the styrene-acrylic resin.

  The styrene-acrylic resin is a polymer obtained by polymerizing a monomer containing styrene and an acrylic compound. Examples of the acrylic compound used as the material for the styrene-acrylic resin include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, Acrylic acid esters such as cyclohexyl acrylate and isobornyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate Methacrylic acid esters such as sulfoethyl acrylate, sulfoethyl methacrylate, hydro Siethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, caprolactone modified hydroxy acrylate, caprolactone modified hydroxy methacrylate, bishydroxyethyl phthalate monoacrylate, bishydroxyethyl phthalate monomethacrylate, 2-acryloxyethyl acid phosphate Fate, 2-methacryloxyethyl acid phosphate, 2-acryloxypropyl acid phosphate, 2-methacryloxypropyl acid phosphate, 2-acryloxy-3-chloropropyl acid phosphate, 2-methacryloxy-3-chloropropyl acid Phosphate, 2-acryloxyphenyl ethyl phenyl Acid, 2-methacryloxyphenyl ethyl phenyl phosphate, acrylonitrile, methacrylonitrile, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, N-methylolacrylamide, acrylamide, methacrylamide, glycidyl acrylate, Examples thereof include glycidyl methacrylate. These may be used alone or in combination of two or more.

Examples of monomers other than those used for producing styrene-acrylic resins include unsaturated carboxylic acids such as crotonic acid, itaconic acid, maleic acid, maleic anhydride, and fumaric acid, vinyl sulfonic acid, styrene sulfonic acid, and the like. Sulfonic acid group-containing monomers, allyl alcohol, vinyl toluene, α-methylstyrene and other aromatic monomers, vinyl acetate and other vinyl esters, vinyl chloride, vinylidene chloride and other halogen-containing monomers, vinyl ethers 4-vinylpyridine, vinylimidazole and the like. These may be used alone or in combination of two or more.
Among the above monomers, it is preferable to use a monomer selected from methyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate and acrylic acid, and styrene.

  Next, a method for manufacturing the ALC panel 1 in which the embedded metal fitting 10 of the present invention is embedded will be described. The ALC panel 1 has a first rust-preventing treatment process for forming a rust-preventing coating made of styrene-acrylic resin on the surface of the embedded metal fitting 10, and the embedded metal fitting 10 that has undergone the first anti-rust treatment process is fixed to the reinforcing reinforcing bar 2. And a second resin rust preventive layer containing styrene-acrylic resin and a cement rust preventive layer containing cement are formed on the surface of the reinforcing reinforcing bar 2 and the surface of the embedded metal fitting 10 after the fixing step. 2. A semi-cured body preparation step in which a raw slurry is placed in a mold having the reinforcing reinforcing bars 2 that have undergone the second rust-proofing process, and a semi-cured body is manufactured by producing a semi-cured body. The semi-cured product obtained through the process is manufactured through an autoclave curing process for curing the autoclave. Hereinafter, each step will be described.

  First, a rust preventive film made of styrene-acrylic resin is formed on the surface of the embedded metal fitting 10 (first rust preventive treatment step). In the first antirust treatment step, a liquid material containing a styrene-acrylic resin is applied to the surface of the embedded metal fitting 10 by a known technique, or the embedded metal fitting 10 is immersed in a liquid material containing a styrene-acrylic resin. It can be executed by

  The liquid containing the styrene-acrylic resin is a polymer liquid obtained by polymerizing the above-described monomer (a monomer containing styrene and an acrylic compound). Examples thereof include emulsions containing styrene in a proportion of 10% to 50% by mass, preferably 30% to 50% by mass. Among such styrene-acrylic resin emulsions, those of the soap free type and the soap press type are preferable.

  Next, the embedded metal fitting 10 that has undergone the first rust prevention treatment step is fixed to the reinforcing reinforcing bars 2 (fixing step). In the fixing step, a predetermined number of embedded metal fittings 10 are fixed to predetermined locations of the reinforcing reinforcing bars 2 having a lattice shape as shown in FIG. Specifically, when the attachment piece 11 of the embedded metal fitting 10 is attached so as to sandwich a predetermined portion of the reinforcing bar 2 between the attachment piece 11 and the upper surface 10A of the embedded metal fitting 10, and fixed by a method such as welding. The embedded metal fitting 10 is fixed to the reinforcing reinforcing bar 2.

  A second resin rust preventive layer containing styrene-acrylic resin and a cement rust preventive layer containing cement are formed on the surface of the reinforcing reinforcing bar 2 and the surface of the embedded metal fitting 10 after the fixing process (second rust preventive treatment). Process).

  In the second rust prevention treatment step, first, a second resin rust prevention layer containing a styrene-acrylic resin is formed. The second resin rust preventive layer is obtained by mixing a resin mixture obtained by mixing styrene-acrylic resin, quartz powder, slaked lime, calcium carbonate, water, and the like used for the formation of the rust preventive film with the surface of the embedded metal fitting 10 and the reinforcing reinforcing bar 2. It can apply | coat to the surface of this by a well-known method, or it can form by immersing the reinforcement reinforcement 2 with the embedded metal fitting 10 in the said resin mixture.

  The styrene-acrylic resin contained in the resin mixture is the same as the styrene-acrylic resin contained in the liquid styrene-acrylic resin used to form the anticorrosive film in the first antirust treatment step. Can be used.

  The ratio of each component in the resin mixture (ratio to the total mass of the resin mixture) is 10% by mass to 20% by mass of styrene-acrylic resin, 20% by mass to 30% by mass of quartz powder, and 10% by mass of slaked lime. % To 20% by mass, calcium carbonate is preferably 5% to 15% by mass, and a solvent such as water is preferably 28% to 41% by mass.

  Next, a cement-based rust prevention layer is formed on the surface of the reinforcing reinforcing bar 2 with the embedded metal fitting 10 on which the second resin rust prevention layer is formed. The cement-based rust preventive layer is formed by applying a cement-based rust preventive agent containing cement to the surface of the reinforcing rebar 2 with the embedded metal fitting 10 or by using the reinforcing rebar 2 with the embedded metal fitting 10 as the cement-based rust preventive agent. It is formed by dipping.

  The cement-based rust preventive agent for forming the cement-based rust preventive layer is 60% by mass to 80% by mass of cement with respect to the mass of the cement rust preventive and 5% by mass with respect to the mass of the cement rust preventive agent. What mixes 20 mass% or more and 30 mass% or less of water with respect to the mass of the rust-acrylic resin of 10 mass% or less and a cement rust preventive agent is preferable. As the liquid material of the styrene-acrylic resin contained in the cement-based rust preventive agent, the same material as the liquid material of the styrene-acrylic resin contained in the resin mixture used when forming the second resin layer is used. it can.

  Next, the raw material slurry is placed in a mold in which the reinforcing steel bars 2 with the embedded metal fittings 10 that have undergone the second rust prevention treatment step are disposed to produce a semi-cured body (semi-cured body fabrication step). As the raw material slurry, a slurry obtained by adding water to a solid component mainly composed of a siliceous raw material and a calcareous raw material and kneading can be used.

As the siliceous raw material, one or a combination of two or more kinds of powders or granular materials known as raw materials containing SiO ₂ such as silica stone, silica sand, slag, fly ash and the like can be used.

  As the calcareous raw material, powders or granular materials such as quick lime, slaked lime, ordinary Portland cement, early-strength Portland cement, and other various Portland cements can be used singly or in combination.

  As a material of the raw material slurry, in addition to the solid component and water, a foaming agent such as aluminum powder, a water reducing agent, and the like can be used. In addition, when preparing the raw material slurry, in addition to the above-mentioned main component raw materials, gypsum, repeated raw materials (no need to be generated when a semi-cured material obtained by foaming and hardening the raw material slurry is cut with a piano wire) ) And unnecessary ALC powder (unnecessary portion generated when cutting ALC obtained by curing a semi-cured product) may be added. Addition of these raw materials is preferable because foaming of the raw material slurry is stabilized and raw material costs can be saved.

  The raw material slurry is obtained by adding 50 to 90 parts by mass of water to 100 parts by mass of the total solid components (silicic raw materials, raw materials such as calcareous raw materials and solid components such as gypsum). It is obtained by kneading.

  The raw material slurry produced as described above is placed in a mold having a predetermined shape in which the reinforcing reinforcing bars 2 to which the embedded metal fittings 10 are attached, and the raw material slurry placed in the mold is subjected to a predetermined hardness (for example, A semi-cured material is obtained by semi-curing curing until the hardness becomes such that it can be cut with a piano wire.

  Next, the semi-cured body obtained through the semi-cured body manufacturing process is removed from the mold and cut (demolding / cutting process). In the demolding / cutting process, the semi-cured material obtained through the semi-cured material manufacturing process is demolded from the mold, cut to a predetermined thickness with a piano wire or the like, and unnecessary portions (uneven ends) A plurality of panel-like semi-cured bodies can be obtained by removing unnecessary portions such as portions and adjusting the shape.

  When the panel-shaped semi-cured material obtained by the above-described method is subjected to autoclave curing at 160 ° C. to 200 ° C. for 4 hours to 12 hours (autoclave curing process), the ALC panel 1 in which the embedded metal fitting 10 of Embodiment 1 is embedded is obtained. can get.

<Example>
Hereinafter, the present invention will be described more specifically with reference to examples.
1. Production of ALC embedded with embedded metal fitting of Example 1 and embedded metal fittings of Comparative Examples 1 and 2 (1) First antirust treatment step On the surface of the embedded metal fitting shown in FIG. 2, a styrene-acrylic resin emulsion Was applied to form a 30 μm rust preventive film on the surface, and the embedded metal fitting of Example 1 was obtained. The amount of styrene in the styrene-acrylic resin is 30% by mass with respect to the mass of the resin.

(2) Fixing process As shown in FIG. 1, the embedded metal fitting of Example 1 was fixed to a predetermined portion of the reinforcing reinforcing bar 2 having a lattice shape. Specifically, the attachment piece 11 of the embedded metal fitting 10 is attached so as to sandwich a predetermined portion of the reinforcing reinforcing bar 2 between the attachment piece 11 and the upper surface 10A of the embedded metal fitting 10, and welding is performed. The metal fitting 10 was fixed to the reinforcing steel bar 2.

(3) Second antirust treatment step (i) Formation of second resin layer A resin mixture containing a styrene-acrylic resin was prepared.
The ratio of each component in the resin mixture is 15% by mass of styrene-acrylic resin having a styrene content of 50% by mass, 25% by mass of quartz powder, 15% by mass of slaked lime, 10% by mass of calcium carbonate, It is 35% by mass of water.
The prepared resin mixture was applied to the surface of the embedded metal fitting and the surface of the reinforcing steel bar that had undergone the fixing step, to form a second resin layer.

(Ii) Formation of cement-based rust preventive layer 7% by mass of styrene-acrylic resin having 43% by mass of styrene in the resin, 70% by mass of cement (ordinary Portland cement), and 23% by mass of water A cement-based rust preventive was prepared.
The cement rust preventive agent was applied to the surface of the embedded metal fitting and the reinforcing steel bar on which the second resin layer was formed to form a cement rust preventive layer.

(3) Production process of semi-cured product 65 parts by mass of silica powder, 20 parts by mass of early cement, 11 parts by mass of quicklime powder, 4 parts by mass of gypsum, 70 parts by mass of water and aluminum with respect to 100 parts by mass of these solid components 0.06 part by mass of powder and 0.1 part by mass of a water reducing agent were mixed to prepare a raw material slurry, which was poured into a mold frame provided with reinforcing bars with embedded metal fittings, and foamed and cured. Remove the semi-cured product after 3 hours, cut it into a panel shape with a 0.9 mm piano wire, remove the non-product part around the formwork and the convex and concave parts at the end, and remove the panel-shaped semi-cured product. Produced.

(4) Autoclave Curing Step The semi-cured product obtained in (3) was cured in an autoclave at 180 ° C. for 10 hours to produce an ALC panel in which the embedded metal fitting of Example 1 was embedded.

(5) Production of ALC panel in which the embedded metal fitting of Comparative Example 1 was embedded ALC panel in which the embedded metal fitting of Comparative Example 1 was embedded in the same manner as in Example 1 except that the first rust prevention treatment step was not performed. Was made.

(6) Production of ALC panel in which embedded metal fittings of Comparative Example 2 were embedded The same as Example 1 except that in the first rust prevention treatment step, an epoxy resin was cationically electrodeposited instead of a styrene-acrylic resin emulsion. Thus, an ALC panel in which the embedded metal fitting of Comparative Example 2 was embedded was produced.
Specifically, in Comparative Example 2, 55 mass% of the deformed epoxy resin, 25 mass% of the cured resin, 3 mass% of carbon black, 7 mass% of the extender pigment, and 5 mass% of the rust preventive pigment with respect to the solid mass. The rust preventive film was formed by using an electrodeposition paint containing 3% by mass of a curing catalyst and 2% by mass of an additive and heating and curing at 170 ° C. for 30 minutes.

2. Evaluation test (1) Rust prevention performance (Test method)
About two ALC panels in which the embedded brackets of Example 1 were embedded, two ALC panels in which the embedded brackets of Comparative Example 1 were embedded, and two ALC panels in which the embedded brackets of Comparative Example 2 were embedded, JIS A 5416 “ALC panel 9.4 anti-corrosive performance test” (JIS method) is performed, and the anti-rust performance test of the embedded metal fittings embedded in each panel using the ALC panel after the anti-corrosion test Went.

  The ALC panel after the rust prevention test by the JIS method was disassembled with a mallet, and the rust portion of each embedded metal fitting was copied by applying a transparent sheet, and the area ratio was calculated to obtain the rust ratio. If the rusting rate was 5.0 or less, it was judged that the product had sufficient rust prevention performance.

(result)
In the embedded metal fitting of Example 1 and the embedded metal fitting of Comparative Example 2 that were subjected to the rust prevention test by the JIS method, the rusting rate was 1.0% or less.
In the embedded metal fitting of Comparative Example 1, rust was already generated before welding to the reinforcing steel bars, and after the rust prevention test by the JIS method, the rust generation rate was 20% or more.

  From these results, the embedded metal fitting of Example 1 and the embedded metal fitting of Comparative Example 2 both have sufficient antirust performance, but the embedded metal fitting of Comparative Example 1 that does not have a rust preventive film is also in storage. It was found that rusting did not have sufficient rust prevention performance.

(2) Anchor pull-out test (Test method)
In accordance with JIS A 5416 (ALC panel 9.6 embedded part pull-out strength test), the test was performed according to the following procedure (see FIG. 5).
Each ALC panel 1 serving as a test body was placed in a cantilever state by bringing the end where the embedded metal fitting 10 was embedded 300 mm from the support S to a reaction force stand (not shown) for anchor pull-out test. Then, the load was loaded using the hydraulic jack J to the anchor until the anchor part 3 of the ALC panel 1 broke down. The loading speed was 100 N to 200 N per second, and the maximum load was measured. The size of the ALC panel used as a test body is 100 mm × 600 mm × 1800 mm (thickness, width, length), and the diameter of the reinforcing reinforcing bar is 5 mm. In addition, as an ALC panel used for this test method, the thing different from the ALC panel used for the rust prevention performance test was used.

In FIG. 5, arrow K is the direction of load, B is a steel reaction plate longer than the panel width, R is a load meter, and D is an applied force with sufficient strength to neglect deformation due to load. It is a steel bar. FIG. 5 shows a test of the embedded metal fitting on one end side of the ALC panel, but the same test was performed on the embedded metal fitting on the other end side of the ALC panel.
In addition, this test was performed on two ALC panels for each of the examples and comparative examples. Table 1 shows the maximum load (N) for each ALC panel (described as panel 1 and panel 2), how many mm in the thickness direction from the surface of the ALC there is the top surface of the nut (cover thickness), and the maximum load. The average value of was also shown. Furthermore, in Table 1, the maximum load and the cover thickness at two locations per ALC panel are shown as a and b, respectively.

(Results and discussion)
In the ALC panel in which the embedded metal fitting of Example 1 was embedded, the average value of the maximum load was 15783N, and it was found that the ALC panel had excellent pull-out strength compared to Comparative Example 2.
Furthermore, in the ALC panel in which the embedded metal fitting of Comparative Example 1 is embedded, the average value of the maximum load is 15074N, but the rust prevention performance is insufficient as described in (1).
In the ALC panel in which the embedded metal fitting of Comparative Example 2 was embedded, the average value of the maximum load was 12095 N. Compared with Example 1 and Comparative Example 1, the pullout strength was significantly low.

(3) Summary The embedded metal fitting of Example 1 in which the rust preventive film made of styrene-acrylic resin is formed has sufficient rust prevention performance, and the ALC panel in which the embedded metal fitting is embedded is an anticorrosive agent for an anchor. In addition, it was found that the tensile strength was excellent while the cost required for the equipment could be reduced.
In the ALC panel in which the embedded metal fitting of Comparative Example 1 in which the rust preventive film is not formed is embedded, the rust preventive performance is insufficient although it has excellent pullout strength.
Further, it was found that the embedded metal fitting of Comparative Example 2 on which a rust preventive film formed by cationic electrodeposition coating of epoxy resin was sufficient in rust prevention performance but insufficient in tensile strength.

DESCRIPTION OF SYMBOLS 1 ... ALC panel 2 ... Reinforcing bar 2A ... Reinforcing bar arranged along a longitudinal direction 2B ... Reinforcing bar arranged along a short side direction 3 ... Anchor part 10 ... Embedded metal fitting 10A ... Upper surface 10B ... (Surface of embedded metal) 11 ... Mounting piece 12 ... Cylindrical body 12A ... Lower end (nut)
B ... Reaction force plate D ... Applied steel rod J ... Hydraulic jack K ... Load R ... Load meter S ... Supporting part

Claims (3)

An embedded metal fitting embedded in a lightweight cellular concrete panel,
An embedded metal fitting having a rust-proof coating made of styrene-acrylic resin formed on the surface. The embedded metal fitting according to claim 1, wherein a thickness of the rust preventive film is 20 μm or more and 50 μm or less. A first rust-preventing treatment step of forming a rust-preventing film made of styrene-acrylic resin on the surface of the embedded metal fitting embedded in the lightweight cellular concrete panel;
A fixing step of fixing the embedded metal fittings having undergone the first rust prevention treatment step to the reinforcing steel;
A second rust preventive treatment step of forming a second resin rust preventive layer containing styrene-acrylic resin and a cement rust preventive layer containing cement on the surface of the reinforcing reinforcing bar and the surface of the embedded metal fitting after the fixing step. When,
A semi-cured material production step of producing a semi-cured material by placing a raw material slurry in a mold frame in which reinforcing reinforcing bars that have undergone the second rust prevention treatment step are disposed;
An autoclave curing step for curing the semi-cured material obtained through the semi-cured material preparation step, by autoclave curing, and a method for producing a lightweight cellular concrete panel.

Images