Concrete reinforcement kit

Abstract

To strengthen and repair concrete without being affected by the environment. [Solution] A concrete reinforcing kit to be applied to a concrete surface, comprising granular calcium hydroxide having an average particle size of 0.5 to 3 μm, a binder selected from the group consisting of cationic binders, nonionic binders, and anionic binders, A kit for reinforcing concrete, comprising: fly ash;

Description

[Technical Field]

[0001] The present invention relates to a kit for reinforcing concrete. [Background technology]

[0002] Currently, the country's infrastructure, including roads, bridges, and tunnels, which were built during the period of high economic growth, is aging, and various problems are arising, including the need for repairs.

[0003] For example, Patent Document 1 discloses a method for repairing cracks in concrete using a repair material that utilizes the metabolic activity of bacteria. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-156023 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the method of Patent Document 1 is susceptible to environmental influences because it relies on bacteria. Therefore, an object of the present invention is to provide a concrete reinforcement kit that can strengthen and repair concrete without being affected by the environment. [Means for solving the problem]

[0006] A concrete reinforcing kit according to one embodiment of the present invention is a concrete reinforcing kit to be applied to a concrete surface, and includes granular calcium hydroxide having an average particle size of 0.5 to 3 μm, a binder selected from the group consisting of cationic binders, nonionic binders, and anionic binders, and fly ash.

[0007] A concrete reinforcing kit according to another embodiment of the present invention is a composite granulated product obtained by composite granulation of the calcium hydroxide and the fly ash, the composite granulated product having an average particle size of 2 to 30 μm.

[0008] A concrete reinforcement kit according to another embodiment of the present invention further includes a carbonated bubble water generator.

[0009] In a concrete reinforcing kit according to another embodiment of the present invention, the cationic binder includes a quaternary ammonium salt polymer.

[0010] In a concrete reinforcing kit according to another aspect of the present invention, the nonionic binder includes an acrylamide polymer.

[0011] In a concrete reinforcing kit according to another embodiment of the present invention, the anionic binder includes an acrylate metal salt polymer. [Effects of the Invention]

[0012] The concrete reinforcing kit of the present invention makes it possible to strengthen and repair concrete without being affected by the environment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail. The following description of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0014] The concrete reinforcing kit of this embodiment contains granular calcium hydroxide with an average particle size of 0.5 to 3 μm, a binder, and fly ash. It is applied to the concrete surface and is primarily used for existing concrete, but may also be used for newly constructed concrete.

[0015] The calcium hydroxide used in this embodiment is granular, with an average particle size of 0.5 to 3 μm, preferably 1 to 2 μm. Granular calcium hydroxide can be produced, for example, by pulverizing the calcium hydroxide into nearly spherical particles using a ball mill or the like. In this specification, the "average particle size" of calcium hydroxide refers to the D50 value in the volume-based particle size distribution obtained by measurement using a laser diffraction / scattering particle size distribution measurement method.

[0016] Examples of the binder used in this embodiment include cationic binders, nonionic binders, and anionic binders.

[0017] Examples of the cationic binder include quaternary ammonium salt polymers and methacrylate quaternary ammonium salt polymers.

[0018] Examples of nonionic binders include acrylamide polymers.

[0019] Examples of the anionic binder include metal acrylate polymers and acrylic sulfonate polymers.

[0020] Examples of the fly ash used in this embodiment include fly ash type I and fly ash type II defined in JIS A 6201:2015 "Fly ash for concrete."

[0021] The composite granulation of calcium hydroxide and fly ash used in this embodiment is not particularly limited, but for example, composite granulation by spray pyrolysis (spray method) can be mentioned.

[0022] The carbonated bubble water generator used in this embodiment sprays carbonated bubble water onto a mixture of calcium hydroxide, binder, and fly ash applied to the concrete surface to re-initiate the hydration reaction, thereby improving the strength of existing concrete. [Example]

[0023] The present invention will be explained in more detail below by way of examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention.

[0024] <Calcium hydroxide> Generally available calcium hydroxide can be used, but in this example, scallop shell powder was fired at 900 to 1000°C for 1 hour, and the resulting calcium oxide was stirred in distilled water at room temperature (15°C) for 1 hour, and then evaporated to dryness at 150°C for 3 hours to obtain calcium hydroxide.

[0025] <Granulation of calcium hydroxide> Granular calcium hydroxide can be obtained by pulverizing calcium hydroxide using a ball mill. As an example, pulverization was performed under the following conditions. Ball mill (Fritsch P-7) Ball: ZrO2 ball (diameter 5 mm) Mass: 10g ball, 4g calcium hydroxide Rotation speed: 800 rpm Operating time: 1 hour When examined with a scanning electron microscope (JSM-6510A manufactured by JEOL Ltd.), it was found that most of the particles had a particle size of 2 μm or less.

[0026] [Compression strength test] The mixture of granular calcium hydroxide and binder, and the mixture with fly ash, were applied to concrete samples and the results were observed. After application, carbonated nanobubble water was sprayed on the samples and the compressive strength was measured based on JIS A 1108:2018 (Test method for compressive strength of concrete).

[0027] <Binder> In this example, the following binders were used: Cationic binder: Senka Actgel CD100 (manufactured by Senka Co., Ltd.) Nonionic binder: Senka Actgel NS100 (manufactured by Senka Co., Ltd.) Anionic binder: Senka Actgel AP200 (manufactured by Senka Co., Ltd.)

[0028] <Binder liquid> The binder liquid to be mixed with calcium hydroxide was prepared as follows. Cationic binder solution: Prepare by mixing 5g of cationic binder with 200ml of water. Nonionic binder solution: Prepare by mixing 27g of nonionic binder with 300ml of water. Anionic binder solution: Prepared by mixing 0.8 g of anionic binder with 80 ml of water.

[0029] <Fly ash> In this example, fly ash type I specified in JIS A 6201:2015 "Fly ash for concrete" was used.

[0030] <Concrete sample> Hardened concrete 28 days after production was used.

[0031] <Carbonated bubble water> In this example, the following carbonated bubble water generator was used, and the pressure was set to perform the work. NC Guard α (Koizumi Seima Co., Ltd.) Water absorption pressure 0.26μPa Discharge pressure 1.8MPa

[0032] [Preparation of specimen] Example 1 20 g of calcium hydroxide was mixed with 200 ml of cationic binder liquid to prepare nine bottles of the mixture.

[0033] Example 2 Three bottles of the mixture prepared in the same manner as in Example 1 were mixed with 2 g of fly ash.

[0034] Example 3 20 g of calcium hydroxide was mixed with 300 ml of nonionic binder liquid to prepare nine bottles of the mixture.

[0035] Example 4 Three bottles of the mixture prepared in the same manner as in Example 3 were mixed with 2 g of fly ash.

[0036] Example 5 20 g of calcium hydroxide was mixed with 80 ml of anionic binder liquid to prepare nine bottles of the mixture.

[0037] (Comparative Example 1) The mixture of calcium hydroxide and binder was not applied, and only carbonated bubble water was sprayed.

[0038] [Application to concrete specimens and spraying of carbonated bubble water] The mixture of Example 1 was less sticky but could be applied, and there was no slippage when carbonated bubble water was sprayed. In Example 2, the fly ash dissolved and mixed without any problems. In Example 3, the mixture was sticky and could be applied, but slippage occurred when carbonated bubble water was sprayed. Furthermore, in Example 4, the mixture of the fly ash was worse than in Example 2.

[0039] [Details of the compression strength test] A concrete compressive strength test based on JIS A 1108:2018 was conducted to measure the compressive strength. For the specimens of the examples, measurements were taken on three specimens for each binder liquid, and the average value was calculated. This procedure was performed three times (for a total of nine specimens). For example, Example 1 is represented as Examples 1-1, 1-2, and 1-3. Note that for Examples 2 and 4, which contained fly ash, the procedure was performed once. The test results are shown in Table 1.

[0040] [Table 1]

[0041] From the above results, it can be seen that the compressive strength of each example is improved compared to the comparative example.

[0042] In this example, the concrete strength was also improved, but the concrete strength can be improved more effectively by controlling the particle shape, size, surface potential, etc. of calcium hydroxide and fly ash and granulating them into a composite.

Claims

1. A concrete reinforcement kit to be applied to a concrete surface, Granular calcium hydroxide having an average particle size of 0.5 to 3 μm; a binder selected from the group consisting of cationic binders, nonionic binders, and anionic binders; Fly ash and Concrete reinforcement kit including:

2. 2. The concrete reinforcement kit according to claim 1, wherein the calcium hydroxide and the fly ash are composite granulated and have an average particle size of 2 to 30 μm.

3. The kit for reinforcing concrete according to claim 1 or 2, further comprising a carbonated bubble water generator.

4. 3. The concrete reinforcing kit according to claim 1, wherein the cationic binder comprises a quaternary ammonium salt polymer.

5. The concrete reinforcement kit according to claim 1 or 2, wherein the nonionic binder comprises an acrylamide polymer.

6. 3. The concrete reinforcing kit according to claim 1, wherein the anionic binder comprises a metal acrylate polymer.

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