Concrete and mortar with the ability to inhibit marine organism fouling.

Abstract

To provide concrete mortar having a marine organism adherence inhibiting property, the concrete mortar not requiring additional handling or cost when used and a method of inhibiting marine organism adherence to the concrete mortar.SOLUTION: Concrete mortar having a marine organism adherence inhibiting property includes a metal chelate compound including the Groups 3 to 14 metal ions and a chelate component.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to concrete-mortar having the ability to suppress the adhesion of marine organisms, and a method for suppressing the adhesion of marine organisms to concrete-mortar.

Background Art

[0002] <000001> Marine organisms such as shellfish, barnacles, tube-dwelling polychaetes, and algae adhere to the surface of concrete-mortar structures in contact with seawater. In particular, the adhesion of marine organisms to the intake ports, pipes, and discharge channels of harbor facilities such as nuclear power plants, thermal power plants, and coastal plants that use a large amount of seawater causes a decrease in the seawater flow rate due to the narrowing and blockage of the water pipes, so regular removal work is required after stopping the plant operation. Thus, the adhesion of marine organisms to concrete-mortar structures has a very serious adverse impact on the industrial world. Therefore, it is necessary to prevent such damage caused by marine organisms.

[0003] As a method for preventing the adhesion of marine organisms to concrete-mortar, for example, Patent Document 1 discloses a method of generating hypochlorite by electrolyzing seawater and injecting this into seawater to prevent the adhesion of marine organisms to the structure surface. Further, Patent Document 2 discloses an oligomer-like room-temperature curable silicone rubber-based paint for preventing the adhesion of marine organisms.

[0004] Although not intended to suppress the adhesion of marine organisms, Patent Document 3 discloses a concrete antibacterial agent containing a silver compound, a copper compound, and an ion-retaining compound for suppressing the corrosion of concrete in sewage treatment facilities and the like caused by sulfur-oxidizing bacteria and sulfur-reducing bacteria.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] As mentioned above, preventing marine organisms from attaching to marine concrete and mortar structures requires the installation of additional equipment or painting after construction. Furthermore, maintaining these performance aspects incurs costs and effort, such as the operation and maintenance of the equipment and the need for repainting. For example, the method described in Patent Document 1 may be effective at a laboratory level, but it would be too costly to implement at a level suitable for actual port facilities, and there are concerns about side effects from hypochlorite. The paints described in Patent Document 2, etc., require periodic repainting. Furthermore, although not intended to suppress the attachment of marine organisms, Patent Document 3 describes adding silver compounds, copper compounds, and ion-retaining compounds as antibacterial agents for concrete to a mortar component containing water. However, if metal compounds and ion-retaining compounds are added separately to a composition containing strongly alkaline cement, metal chelate compounds will not be formed, and the ion-retaining compounds (such as chelate components) that remain without chelating with metal ions may inhibit the hardening of the cement. The present invention has been made in view of the above circumstances, and its purpose is to provide concrete mortar having the ability to suppress the attachment of marine organisms, and a method for suppressing the attachment of marine organisms to concrete mortar, without requiring the extra effort and cost described above. [Means for solving the problem]

[0007] The inventors of this invention conducted extensive research to solve the above problems. As a result, they discovered that the above problems could be solved by incorporating a metal chelate compound into concrete and mortar, and thus completed the present invention. The present invention is described below.

[0008] [1] Concrete mortar having the ability to inhibit marine organism adhesion, characterized by containing metal chelate compounds containing Group 3 to 14 metal ions and chelate components. [2] The concrete mortar having the ability to inhibit marine organism adhesion as described in [1], comprising 0.1 parts by mass or more and 0.5 parts by mass or less of the Group 3 to 14 metal ions per 100 parts by mass of cement components contained in the concrete mortar. [3] The concrete mortar having the ability to inhibit marine organism adhesion according to [1], wherein the Group 3 to 14 metal ion is at least one selected from cobalt ions and copper ions. [4] The concrete mortar having the ability to inhibit marine organism adhesion according to [2], wherein the Group 3 to 14 metal ion is at least one selected from cobalt ions and copper ions. [5] A concrete or mortar having the ability to inhibit marine organism adhesion according to any one of [1] to [4] above, wherein the chelating component is an aminocarboxylic acid-based chelating component. [6] The concrete mortar having marine biofouling inhibitory ability according to [5], wherein the aminocarboxylic acid chelating component is at least one selected from ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, and nitrilotriacetic acid. [7] A method for suppressing the attachment of marine organisms to concrete or mortar, characterized in that the concrete or mortar is blended with a metal chelate compound containing group 3 to 14 metal ions and a chelating component. [8] The method according to [7], wherein 0.1 parts by mass or more and 0.5 parts by mass or less of the group 3 to 14 metal ions are added to the cement components contained in the concrete or mortar. [Effects of the Invention]

[0009] According to the present invention, it becomes possible to easily manufacture concrete and mortar that have the ability to suppress the attachment of marine organisms. If nuclear power plants, thermal power plants that use large amounts of seawater, and port facilities that come into contact with seawater are constructed using concrete and mortar according to the present invention that have the ability to suppress the attachment of marine organisms, the attachment of marine organisms can be suppressed, and maintenance costs and the need for reconstruction can be reduced. Therefore, the present invention is extremely useful in industry. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows photographs of the appearance of concrete samples prepared with the metal chelate compound according to the present invention, and concrete samples prepared with conventional antibacterial agents, after they have been immersed in seawater. [Figure 2] Figure 2 is a photograph of the appearance of a concrete sample prepared with the cobalt chelate compound according to the present invention after it has been immersed in seawater. [Figure 3] Figure 3 is a photograph of the appearance of a cylindrical mortar specimen prepared by separately mixing basic copper(II) carbonate and ethylenediaminetetraacetic acid into cement. [Figure 4] Figure 4 is a photograph of the appearance of a rectangular mortar specimen that does not contain metal chelate compounds after being immersed in seawater. [Figure 5] Figure 5 is a photograph of the appearance of a rectangular mortar specimen prepared with the metal chelate compound according to the present invention after it has been immersed in seawater. [Figure 6] Figure 6 shows a photograph of the appearance of a rectangular mortar specimen prepared by separately mixing basic copper(II) carbonate and ethylenediaminetetraacetic acid into cement, after immersion in seawater. [Modes for carrying out the invention]

[0011] The concrete-mortar having the ability to suppress marine organism adhesion according to the present invention contains a metal chelate compound containing metal ions of Groups 3 to 14 and a chelate component. In the present disclosure, the concrete-mortar refers to concrete and / or mortar, and includes, for example, a concrete structure repaired with mortar.

[0012] The metal ions of Groups 3 to 14 constituting the metal chelate compound are not particularly limited as long as they can suppress the adhesion of marine organisms to concrete. For example, one or more first transition metal ions selected from scandium ions, titanium ions, vanadium ions, chromium ions, manganese ions, iron ions, cobalt ions, nickel ions, and copper ions; one or more second transition metal ions selected from zirconium ions, molybdenum ions, palladium ions, and silver ions; Group 12 metal ions such as zinc ions; Group 13 metal ions such as aluminum ions; and Group 14 metal ions such as tin and lead. One or more first transition metal ions selected from titanium ions, chromium ions, manganese ions, iron ions, cobalt ions, nickel ions, and copper ions are preferable, and at least one selected from cobalt ions and copper ions is more preferable. The metal ions of Groups 3 to 14 may be used alone or in combination of two or more.

[0013] The metal chelate compound may contain an alkali metal ion in addition to the metal ions of Groups 3 to 14 for the ability to suppress marine organism adhesion. The metal chelate compound containing an alkali metal ion has higher water solubility and can be more easily dispersed in the concrete-mortar. Examples of the alkali metal ion include one or more selected from lithium ions, sodium ions, potassium ions, rubidium ions, and cesium ions. One or more selected from lithium ions, sodium ions, and potassium ions are preferable, and one or more selected from sodium ions and potassium ions are more preferable. The alkali metal ion may be used alone or in combination of two or more.

[0014] The chelating component is not particularly limited as long as it can form a chelate with group 3 to 14 metal ions in solution. Examples include ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, ethylenediaminediacetic acid, 1,2-diaminopropanetetraacetic acid, 1,3-diaminopropanetetraacetic acid, hexamethylenediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid, diaminopropanoltetraacetic acid, hydroxyethylenediaminetriacetic acid, glycol etherdiaminetetraacetic acid, ethylenediaminedi(o-hydroxyphenyl)acetic acid, iminodiacetic acid, hydroxyethyliminodiacetic acid, nitrilotriacetic acid, methylglycinediacetic acid, and ethylenediaminediacetic acid. Aminocarboxylic acid-based chelating components such as hopionic acid, nitrilotripropionic acid, ethylenediamine disuccinic acid, 1,3-diaminopropane disuccinic acid, glutamic acid-N,N-diacetic acid, and aspartic acid-N,N-diacetic acid; carboxylic acid-based chelating components such as hydroxyethylidenediphosphonic acid, nitrilotrismethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, 2-phosphono-1,2,4-butanetricarbonate, phosphonohydroxyacetic acid, and hydroxyethylmethylenephosphonic acid; and hydroxycarboxylic acid-based chelating components such as gluconic acid, citric acid, tartaric acid, and malic acid can be used. The chelating components are preferably water-soluble. These chelating components may be used individually or in combination of two or more. Among these, aminocarboxylic acid-based chelating components are preferred from the viewpoint of strong chelating power with group 3 to 14 metal ions. Preferred aminocarboxylic acid-based chelating components include one or more selected from ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, and nitrilotriacetic acid. Chelating agents containing these chelating components are inexpensive and readily available, and they stably dissolve metal components, allowing for the easy preparation of clear metal chelate solutions.

[0015] Even if a metal compound and a chelating agent are separately added to a mixture containing cement and water, a metal chelate compound may be partially formed. However, since a dispersion containing cement is generally strongly alkaline with a pH of 12 to 13, metal ions become insoluble hydroxides that are insoluble in water due to the high alkalinity, and thus stable metal chelates may not be able to be formed. Therefore, it is preferable to prepare a metal chelate compound or its solution from a metal compound and a chelating agent in advance and then mix the obtained metal chelate compound or its solution with cement or the like.

[0016] The metal compound used for preparing the metal chelate compound solution is not particularly limited as long as it can react with the chelating agent to form a metal chelate compound and is not a chemical species that has an adverse effect on concrete, mortar, and concrete and mortar structures. For example, oxides, hydroxides, carbonates, nitrates, sulfates, phosphates, borates, silicates, etc. can be used. Among these, metal oxides, metal hydroxides, and metal carbonates are preferred. By preparing a metal chelate compound solution using these metal compounds, it is possible to suppress the incorporation of unnecessary elements into the concrete and mortar. Even water-insoluble compounds such as metal hydroxides can gradually react with the chelating agent in water to form a metal chelate compound.

[0017] The chelating agent used in preparing a metal chelate compound solution is not particularly limited as long as it contains the chelating component that constitutes the target metal chelate compound and has sufficiently high solubility in the solvent. Examples include alkali metal salts, ammonium salts, and amine salts of the chelating component. Examples of alkali metal ions constituting the alkali metal salt include one or more selected from lithium ions, sodium ions, potassium ions, rubidium ions, and cesium ions, with one or more selected from lithium ions, sodium ions, and potassium ions being preferred, and one or more selected from sodium ions and potassium ions being more preferred. Examples of amine components constituting the amine salt include ammonia, ethylenediamine, triethylenetetramine, diisopropanolamine, triethanolamine, monoethanolamine, diethanolamine, monoisopropanolamine, triisopropanolamine, diethylenetriamine, diethylamine, dibutylamine, hexahydroaniline, pentaethylenehexamine, allylamine, 2-aminopropanol, 3-aminopropanol, 4-aminobutanol, 4-methylaminobutanol, and ethylaminoethylamine. The countercations that make up the chelating agent may be used individually or in combination of two or more types.

[0018] For preparing metal chelate compound solutions, it is preferable to use water; alcohol-based solvents such as methanol, ethanol, and 2-propanol; and mixed solvents thereof. It is preferable that the solvent in the metal chelate compound solution contains at least water; for example, the concentration of water in the solvent is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. It is particularly preferable to use substantially only water as the solvent; therefore, the metal chelate compound solution is preferably an aqueous solution of the metal chelate compound. Using substantially only water as the solvent means that the presence of solvents other than water is below the detection limit, or that no organic solvents other than water are intentionally added or mixed in.

[0019] In preparing a metal chelate compound solution, the proportions of Group 3-14 metal ions, alkali metal ions, and chelating components for inhibiting marine organism adhesion can be adjusted according to the proportions of each component in the target metal chelate compound. While the concentration of each component in the reaction solution is not particularly limited, if it is too low, the total amount of solvent used during mixing with cement will be excessive, potentially preventing the concrete / mortar from achieving its intended performance. Therefore, for example, the amounts of each component should be determined so that the concentration of the target metal chelate compound in the reaction solution is between 10% by mass and 60% by mass. A concentration of 30% by mass or higher is more preferable.

[0020] The amount of chelating agent added to the reaction solution for preparing the metal chelate compound is preferably equal to or greater than the theoretical amount required for chelation coordination with the metal component. Depending on the valence of the metal ion, it is more preferable to adjust the amount to between 1 mole and 1.5 moles per mole of the metal ion to be coordinated. The metal ions should include not only group 3 to 14 metal ions for inhibiting marine organism adhesion, but also cations such as alkali metal ions and ammonium ions.

[0021] Metal chelate compound solutions can be prepared by dissolving a metal compound containing group 3-14 metal ions and a chelating agent in a solvent. Alternatively, a solution of the metal compound and / or a chelating agent may be used.

[0022] The reaction conditions are not particularly limited, but for example, the temperature at which the metal compound and chelating agent are mixed in the solvent can be 10°C or higher and below the boiling point of the solvent, and the reaction may also be carried out at room temperature or under reflux conditions.

[0023] Furthermore, the pH of the reaction solution may be adjusted as needed. Examples of pH adjusting agents include hydroxides such as sodium hydroxide and potassium hydroxide; carbonates such as sodium carbonate, potassium carbonate, and ammonium carbonate; bicarbonates such as sodium bicarbonate, potassium bicarbonate, and ammonium bicarbonate; and alkaline agents such as ammonia or amines.

[0024] The resulting reaction solution may be used as is as a metal chelate compound solution, or it may be filtered or concentrated before use. Alternatively, the metal chelate compound may be purified from the reaction solution. The purification method is not particularly limited and can be done using conventional methods, such as crystallization or drying. Conventional drying methods can be used, such as reduced-pressure concentration, spray drying, or drum drying.

[0025] Concrete and mortar are generally composed primarily of cement, aggregates, and water. Aggregates are classified into coarse aggregates and fine aggregates. Generally, coarse aggregates are those that remain in a 5mm sieve at a rate of 85% or more by mass, while fine aggregates are those that pass through a 10mm sieve completely and contain at least 85% by mass of particles 5mm or smaller. Mortar contains fine aggregates as its aggregate, while concrete contains both fine and coarse aggregates. In typical concrete, aggregates make up about 70% of the total composition.

[0026] The concrete mortar according to the present invention contains a metal chelate compound comprising group 3 to 14 metal ions and a chelating agent. In particular, the concrete mortar according to the present invention does not have a layer of metal chelate compound on its surface, but rather the metal chelate compound is dispersed throughout the entire surface. As a result, when seawater comes into contact with the concrete mortar according to the present invention, the metal chelate compound is thought to act over a long period of time, suppressing the adhesion of marine organisms to its surface.

[0027] In the concrete mortar according to the present invention, the ratio of group 3 to 14 metal ions to 100 parts by mass of cement component is preferably 0.1 parts by mass or more and 0.5 parts by mass or less. If the ratio is 0.1 parts by mass or more, the effect of suppressing marine organism adhesion can be more reliably exhibited, and if it is 0.5 parts by mass or less, the strength of the concrete can be more reliably ensured. The ratio can be determined from the amounts of cement component and group 3 to 14 metal ions used during the preparation of the concrete mortar according to the present invention, if these amounts are known. If these amounts are unknown, the ratio can be determined by analyzing the concrete mortar according to the present invention after hardening. For example, the elemental distribution on the surface of the concrete mortar can be analyzed by electron probe microanalysis (EPMA). Alternatively, the amount of cement can be estimated by taking a sample from the concrete mortar, crushing it, adding hydrochloric acid and stirring, filtering it, and then quantifying the amount of calcium oxide contained by applying the filtrate obtained from titration with an EDTA standard solution.

[0028] The proportion of the metal chelate compound in the concrete mortar according to the present invention can be appropriately adjusted within a range that effectively suppresses the attachment of marine organisms. For example, it can be 0.1% by mass or more and 1% by mass or less relative to the total amount of concrete mortar. If the proportion is 0.1% by mass or more, the effect of suppressing the attachment of marine organisms by the metal chelate compound can be more reliably exerted, and if it is 1% by mass or less, the strength of the concrete mortar can be more reliably ensured.

[0029] Furthermore, the proportion of metal components that exhibit the effect of inhibiting marine organism adhesion in concrete mortar according to the present invention can be adjusted as appropriate, but for example, it can be 0.005% by mass or more and 5% by mass or less, and preferably 0.2% by mass or more and 1% by mass or less.

[0030] The concrete mortar according to the present invention can be produced by blending a metal chelate compound into concrete mortar. The chelate compound should be uniformly mixed before the cement-containing mixture hardens. For example, it is preferable to add it when mixing cement powder, aggregates such as gravel, sand, crushed stone, and crushed sand, and water. In this case, a solid metal chelate compound may be added, or a solution of the metal chelate compound may be added.

[0031] The concrete mortar according to the present invention may contain additives other than cement, aggregate, metal chelate compounds, and water. Examples of additives include fly ash, silica fume, blast furnace slag powder, leavening agents, air-entraining agents, water-reducing agents, air-entraining water-reducing agents, fluidizing agents, and setting retarders.

[0032] As described above, concrete mortar with the ability to inhibit marine organism adhesion can be obtained. Because the concrete mortar according to the present invention has the ability to inhibit marine organism adhesion itself, there is no need to introduce equipment or paint to inhibit marine organism adhesion, and its effect can be maintained over a long period of time. [Examples]

[0033] The present invention will be described in more detail below with reference to examples, but the present invention is not limited by the following examples, and it is certainly possible to implement it with appropriate modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of the present invention.

[0034] Example 1 Gravel-filled cement ("Instant Concrete," manufactured by Toyo Materan Co., Ltd.) (400g) and a 41% by mass aqueous solution of ethylenediaminetetraacetic acid copper disodium ("Kirest Cu-40," manufactured by Kirest Co., Ltd.) (6g) were mixed, water (54mL) was added little by little and kneaded, and the mixture was poured into two 250mL paper cups, anchor hooks were placed inside, and the mixture was cured at room temperature for 3 days to produce concrete cylinders with a diameter of approximately 6cm and a height of approximately 4cm. Assuming a cement content of 30% by mass based on the safety data sheet information for the gravel-filled cement product used, the proportion of copper to the cement component is approximately 0.3% by mass.

[0035] Comparative Example 1 Concrete cylinders were prepared in the same manner as in Example 1, except that 4 g of a concrete antibacterial agent (silver / copper-supported zeolite, "Zeomighty," manufactured by Sinanen Zeomic Co.), copper zinc, Ag-supported coral calcium ("Coral Bio-SI-II," manufactured by Okinawa Coral Co.), or Ni antibacterial powder was used instead of ethylenediaminetetraacetate copper disodium, and the amount of water was changed to 60 g. For comparison, concrete cylinders were also prepared without the use of any additives.

[0036] Example 2: Marine biofouling inhibition test Ropes were attached to the anchor hooks of the concrete cylinders in Example 1 and Comparative Example 1, and they were installed at a position approximately 1 m ± 50 cm underwater from the top of the quay at Kashiwazaki Marina in Kashiwazaki City, Niigata Prefecture. The difference in sea level between high and low tide at the test site was less than 50 cm, so each concrete sample was always submerged in the sea. On the 162nd day after installation, each concrete cylinder was pulled up and its appearance was observed. Photographs of the appearance of each concrete cylinder are shown in Figure 1. As shown in Figure 1, marine organisms such as algae were attached to the entire surface of the control concrete cylinder without additives and the concrete cylinder containing common antibacterial agents (Figure 1(1),(3)~(6)). In contrast, the adhesion of marine organisms was significantly suppressed on the concrete cylinder containing ethylenediaminetetraacetic acid copper disodium, and part of the surface of the concrete cylinder was exposed. Note that the Leathesia marina shown on the left side of Figure 1(2) was attached to the concrete cylinder on the left, and not to the concrete cylinder of Example 1.

[0037] Example 3 A concrete cylinder was fabricated in the same manner as in Example 1, except that a 48.5% by mass aqueous solution of ethylenediaminetetraacetic acid cobalt disodium tetrahydrate ("Kirest Co," manufactured by Kirest Co., Ltd.) was used instead of ethylenediaminetetraacetic acid cobalt disodium (containing 41% by mass of ethylenediaminetetraacetic acid cobalt disodium). The cylinder was then placed in the sea in the same manner as in Example 2, and on the 87th day after placement, the cylinder was pulled up and its appearance was observed. A photograph of the cylinder's appearance is shown in Figure 2. As shown in Figure 2, the adhesion of marine organisms to the concrete cylinder containing ethylenediaminetetraacetic acid cobalt disodium was clearly suppressed, and the surface of the concrete sample was partially exposed.

[0038] Example 4: Compression strength test Copper or cobalt was added to a mixture of cement ("Ordinary Portland Cement," manufactured by Ube Mitsubishi Cement Co.) and standard sand using a 41% by mass aqueous solution of ethylenediaminetetraacetic acid copper disodium ("Kirest Cu-40," manufactured by Kirest Co.) and ethylenediaminetetraacetic acid cobalt disodium tetrahydrate ("Kirest Co," manufactured by Kirest Co.) so that the ratio of copper or cobalt to cement was as shown in Table 1. The mixture was then kneaded in a ratio of cement:standard sand:water = 1:2.5:0.5 (by mass ratio) to prepare cylindrical specimens of φ50 mm × 100 mm. The prepared specimens were immersed in water for curing, and their compressive strength was measured on the 7th and 28th days using a compressive strength tester (manufactured by Tokyo Koki Testing Machine Co., Ltd.). The results are shown in Table 1.

[0039] [Table 1]

[0040] As shown in Table 1, the compressive strength of the mortar decreased as the amount of added transition metal increased. Mortar and concrete harden over time, but their manufacturing efficiency and practical compressive strength are limited to 20 N / mm². 2 Considering the above, it can be said that the proportion of transition metals to cement components is preferably 0.5% by mass or less.

[0041] Example 5: Compression strength test (1) Preparation of the sample of the present invention To achieve a copper content of 0.3% by mass relative to the cement, copper was added to a mixture of cement ("Ordinary Portland Cement," manufactured by Ube Mitsubishi Cement Co., Ltd.) and standard sand using a 41% by mass aqueous solution of ethylenediaminetetraacetic acid copper disodium ("Kirest Cu-40," manufactured by Kirest Co., Ltd.). The mixture was then kneaded in a ratio of cement:standard sand:water = 1:2.5:0.5 (by mass) to prepare cylindrical specimens measuring φ50 mm × 100 cm in height.

[0042] (2) Preparation of comparative sample 1 Basic copper(II) carbonate was added to a mixture of cement ("Ordinary Portland Cement," manufactured by Ube Mitsubishi Cement Co., Ltd.) and standard sand so that the copper content relative to the cement was 0.3% by mass. A 40% by mass aqueous solution of tetrasodium ethylenediaminetetraacetic acid was then added so that the copper and ethylenediaminetetraacetic acid were equimolar. The mixture was then kneaded in a ratio of cement:standard sand:water = 1:2.5:0.5 (by mass ratio) to prepare cylindrical specimens measuring φ50 mm × 100 cm in height.

[0043] (3) Strength test Two cylindrical specimens were prepared and immersed in water for 28 days for underwater curing. Compressive strength was measured using a compression strength tester (manufactured by Tokyo Koki Testing Machine Co., Ltd.), and the average value was calculated. However, comparative sample 1, prepared by separately adding copper compounds and chelating components to the cement composition, did not harden sufficiently, as shown in Figure 3, and partially collapsed during demolding. It did not have enough strength to be loaded onto the testing machine, and therefore its strength could not be measured. The reason for this is thought to be that, due to the strong basicity of the cement, copper and ethylenediaminetetraacetic acid could not react, and the free ethylenediaminetetraacetic acid inhibited hardening. On the other hand, cylindrical specimens prepared using an aqueous solution of copper chelate compounds hardened sufficiently to allow for strength measurement, with an average strength of 30.8 N / mm². 2 That was the case.

[0044] Example 6: Marine biofouling inhibition test (1) Preparation of comparative sample 2 Cement ("Ordinary Portland Cement," manufactured by Ube Mitsubishi Cement Co., Ltd.), standard sand, and water were mixed in a ratio of cement:standard sand:water = 1:2.5:0.5 (by mass) to prepare 10cm x 10cm x 10cm rectangular specimens.

[0045] (2) Preparation of the sample of the present invention To achieve a copper content of 0.3% by mass relative to the cement, copper was added to a mixture of cement ("Ordinary Portland Cement," manufactured by Ube Mitsubishi Cement Co., Ltd.) and standard sand using a 41% by mass aqueous solution of ethylenediaminetetraacetic acid copper disodium ("Kirest Cu-40," manufactured by Kirest Co., Ltd.). The mixture was then kneaded in a ratio of cement:standard sand:water = 1:2.5:0.5 (by mass ratio) to prepare 10cm × 10cm × 10cm rectangular specimens.

[0046] (3) Preparation of comparative sample 3 Basic copper(II) carbonate was added to a mixture of cement ("Ordinary Portland Cement," manufactured by Ube Mitsubishi Cement Co., Ltd.) and standard sand so that the copper content relative to the cement was 0.3% by mass. A 40% by mass aqueous solution of tetrasodium ethylenediaminetetraacetic acid was then added so that the copper and ethylenediaminetetraacetic acid were equimolar. The mixture was then kneaded in a ratio of cement:standard sand:water = 1:2.5:0.5 (by mass ratio) to prepare 10cm × 10cm × 10cm rectangular specimens.

[0047] (4) Marine biofouling inhibition test As described above, a carabiner was attached to the anchor hook of the prepared rectangular specimen and secured to a metal bar. A rope was tied to the metal bar and suspended from a steel float moored in Niigata East Port, positioned approximately 40-60 cm above the sea surface. Six weeks after installation, each rectangular specimen was retrieved and its appearance was observed. Photographs of the top and side views of each rectangular specimen are shown in Figures 4-6. As shown in Figure 4, comparative sample 2, which did not have copper compounds added, had barnacles attached to its entire surface, and green algae were also attached to the top surface and some of the sides. In contrast, as shown in Figure 5, the amount of barnacles attached to the sample of the present invention to which the copper chelate compound was added was clearly reduced, the surface of the sample was partially exposed, and no algal attachment was observed. On the other hand, as shown in Figure 6, comparative sample 3, which was prepared by separately mixing the copper compound and chelating component with cement, did not show a clear inhibitory effect on marine organism fouling compared to comparative sample 2, which did not contain the copper compound, and green algae were still attached. The reason for this is thought to be that, due to the strong basicity of the cement during sample preparation, the copper compound and chelating component could not react, and the water-insoluble copper compound (basic copper carbonate) was present alone in the sample, thus failing to exert any effect on organisms in the seawater.

Claims

1. A concrete mortar having the ability to suppress the attachment of marine organisms, It contains metal chelate compounds containing group 3 to 14 metal ions and chelate components, A concrete mortar having the ability to inhibit marine organism adhesion, characterized by containing 0.1 parts by mass or more and 0.5 parts by mass or less of the Group 3 to 14 metal ions per 100 parts by mass of cement components contained in the concrete mortar.

2. The concrete mortar having marine organism fouling inhibitory ability according to claim 1, wherein the group 3 to 14 metal ions are at least one selected from cobalt ions and copper ions.

3. The concrete mortar having the ability to inhibit marine organism adhesion according to claim 1 or 2, wherein the chelating component is an aminocarboxylic acid-based chelating component.

4. The concrete mortar having marine biofouling inhibitory ability according to claim 3, wherein the aminocarboxylic acid-based chelating component is at least one selected from ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, and nitrilotriacetic acid.

5. A method for suppressing the adhesion of marine organisms to concrete mortar, characterized in that the concrete mortar is blended with a metal chelate compound containing group 3 to 14 metal ions and chelate components in an amount of 0.1 parts by mass to 0.5 parts by mass per 100 parts by mass of cement components contained in the concrete mortar.

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