Concrete reinforcing agent and preparation method thereof

Abstract

The invention discloses a concrete reinforcing agent and a preparation method thereof, and relates to the technical field of concrete production, and the concrete reinforcing agent is prepared from the following raw materials in parts by mass: 60-70 parts of micromolecular polyatomic acid, 30-45 parts of alcohol amine, 1-4 parts of a catalyst, 0.3-0.5 part of a chelating agent, 0.1-0.3 part of a phase transfer catalyst and 0.2-0.5 part of an antioxidant. According to the concrete reinforcing agent and the preparation method thereof, the mixing amount is low, and the economical efficiency is good; the composition is completely water-soluble and convenient to use; the early-stage and later-stage enhancement effects are obvious; the corrosion effect on the reinforcing steel bars is avoided. According to the technical scheme, the technical defects of a traditional concrete reinforcing agent are effectively overcome, and a new technical choice is provided for green and low-carbon development of the building industry.

Description

Technical Field

[0001] This invention relates to the field of concrete production technology, and in particular to a concrete reinforcing agent and its preparation method. Background Technology

[0002] Concrete, as one of the most widely used building materials in modern construction, provides crucial support for modern infrastructure construction due to its excellent plasticity, mechanical properties, and durability. Since its invention, improving the mechanical strength of concrete has been a key research topic in the industry, with the use of chemical admixtures being one of the effective technical approaches. Under the current "dual-carbon" strategy, improving concrete performance through chemical admixtures has dual significance: firstly, it can reduce cement usage while ensuring concrete strength requirements, thereby reducing carbon emissions during concrete production; secondly, it can significantly improve concrete strength while maintaining existing cement usage, thus enhancing the load-bearing capacity and durability of building structures and achieving energy conservation and emission reduction throughout the building's lifecycle. Currently, common concrete chemical admixtures on the market mainly include chloride salts, sulfates, carbonates, alkanolamines, and hydrated calcium silicate crystal nuclei. However, these traditional admixtures generally suffer from the following technical drawbacks: high effective dosage, resulting in poor economic efficiency; some components (such as chlorides) are corrosive to reinforcing steel; significant attenuation of the strengthening effect in the later stages; and poor water solubility, making practical application difficult.

[0003] Therefore, a concrete reinforcing agent and its preparation method were developed to solve the above problems. Summary of the Invention

[0004] This invention proposes a concrete reinforcing agent and its preparation method to solve the problems of high cost, corrosiveness to steel bars, poor later-stage reinforcing effect, and poor water solubility of concrete chemical reinforcing agents.

[0005] The present invention achieves the above objectives through the following technical solutions: This invention discloses a concrete reinforcing agent, which, by weight, is composed of the following raw materials: 60-70 parts by weight of small molecule polyacid, 30-45 parts by weight of alkanolamine, 1-4 parts by weight of catalyst, 0.3-0.5 parts by weight of chelating agent, 0.1-0.3 parts by weight of phase transfer catalyst, and 0.2-0.5 parts by weight of antioxidant.

[0006] Furthermore, the small molecule polyacid includes one or a mixture of several of citric acid, tartaric acid, succinic acid, glutaric acid, and malic acid.

[0007] Furthermore, the preferred polyacids include 15 parts citric acid, 15 parts tartaric acid, 15 parts succinic acid, 10 parts glutaric acid, and 10 parts malic acid.

[0008] Furthermore, the alkanolamine includes one or a mixture of two of ethanolamine and diethanolamine.

[0009] Furthermore, it is preferred that ethanolamine is 15 parts and diethanolamine is 25 parts.

[0010] Furthermore, the catalyst is one or a mixture of two of sodium ethoxide and sodium hydroxide.

[0011] Furthermore, the chelating agent is disodium EDTA.

[0012] Furthermore, the phase transfer catalyst is tetrabutylammonium bromide.

[0013] Furthermore, the antioxidant is one or a mixture of two of 2,6-di-tert-butyl-p-methylphenol and butylated hydroxyanisole.

[0014] The present invention also provides a method for preparing the concrete reinforcing agent, comprising: The catalyst is dissolved in ultrapure water to prepare a 5-10% solution, which is then stored in a nitrogen-protected, sealed container. Weigh the alcoholamine and store it in a sealed container for later use; Prepare a 50% solution of the small molecule polyacid using distilled water; In a reactor equipped with temperature control, stirring and reflux condensation devices, a small molecule polyacid solution and a metal ion chelating agent are added to construct a primary reaction system. The primary reaction system was heated to 40-50℃ and stirred at 200 rpm for 30 min, followed by the addition of a phase transfer catalyst; The temperature was controlled at 40-50℃. The catalyst solution and amine were simultaneously added dropwise to the primary reaction system using a dual-channel precision metering pump. The initial dropping rate was controlled at 0.5 mL / min and continued for 10 min. Increase the temperature to 75-80℃ at a rate of 0.5℃ / min, increase the dropping rate to 1 mL / min, and continue for 20 min. During this period, adjust the dropping rate of the metering pump to maintain the pH at 8.5-9.5. Heat the mixture to 90±5℃, add the remaining raw materials dropwise within 30 minutes, and then maintain the temperature for 4 hours after the reaction is complete. After the reaction is complete and cooled to room temperature, an antioxidant is added, and stirring is continued for 10 minutes to obtain the concrete reinforcing agent.

[0015] The beneficial effects of this invention are as follows: The concrete reinforcing agent and its preparation method proposed in this invention have the advantages of low dosage, good economy, complete water solubility, convenient use, significant early and late strengthening effects, and no corrosive effect on steel reinforcement. This technical solution effectively solves the technical defects of traditional concrete reinforcing agents and provides a new technical option for the construction industry to achieve green and low-carbon development. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0017] The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0018] The specific embodiments of the present invention will be described in detail below.

[0019] Example 1 Example 1 provides a concrete reinforcing agent, which, by weight, is composed of the following raw materials: 60 parts by weight of small molecule polyacid, 30 parts by weight of alkanolamine, 1 part by weight of catalyst, 0.3 parts by weight of chelating agent, 0.1 parts by weight of phase transfer catalyst, and 0.2 parts by weight of antioxidant. The small molecule polyacid includes citric acid, tartaric acid, succinic acid, glutaric acid, and malic acid. The weight percentages of each of these acids are: 15 parts by weight of citric acid, 15 parts by weight of tartaric acid, 15 parts by weight of succinic acid, 10 parts by weight of glutaric acid, and 10 parts by weight of malic acid.

[0020] The alkanolamine is a mixture of ethanolamine and diethanolamine, with a mass ratio of 15 parts ethanolamine and 25 parts diethanolamine. The catalyst is a mixture of sodium ethoxide and sodium hydroxide, with a mass ratio of 0.7 parts sodium ethoxide and 0.3 parts sodium hydroxide. The chelating agent is disodium EDTA. The phase transfer catalyst is tetrabutylammonium bromide. The antioxidant is a mixture of 2,6-di-tert-butyl-p-methylphenol and butyl hydroxyanisole, with mass ratios of 0.025 parts and 0.175 parts, respectively.

[0021] Example 1 also provides a method for preparing the concrete reinforcing agent, comprising: The catalyst is dissolved in ultrapure water to prepare a 5-10% solution, which is then stored in a nitrogen-protected, sealed container. Weigh the alcoholamine and store it in a sealed container for later use; Prepare a 50% solution of the small molecule polyacid using distilled water; In a reactor equipped with temperature control, stirring and reflux condensation devices, a small molecule polyacid solution and a metal ion chelating agent are added to construct a primary reaction system. The primary reaction system was heated to 40-50℃ and stirred at 200 rpm for 30 min, followed by the addition of a phase transfer catalyst; The temperature was controlled at 40-50℃. The catalyst solution and amine were simultaneously added dropwise to the primary reaction system using a dual-channel precision metering pump. The initial dropping rate was controlled at 0.5 mL / min and continued for 10 min. Increase the temperature to 75-80℃ at a rate of 0.5℃ / min, increase the dropping rate to 1 mL / min, and continue for 20 min. During this period, adjust the dropping rate of the metering pump to maintain the pH at 8.5-9.5. Heat the mixture to 90±5℃, add the remaining raw materials dropwise within 30 minutes, and then maintain the temperature for 4 hours after the reaction is complete. After the reaction is complete and cooled to room temperature, an antioxidant is added, and stirring is continued for 10 minutes to obtain the concrete reinforcing agent.

[0022] The synthesized product in Example 1 is completely water-soluble. Its reinforcing effect in concrete was verified, and the test results are shown in Table 1. The tests revealed that even at dosages on the order of a few ten-thousandths, the compressive strength of concrete at 3 days and 28 days of age was significantly improved.

[0023] Table 1

[0024] Example 2 The difference between Example 2 and Example 1 is as follows: Example 2 provides a concrete reinforcing agent, which, by weight, is composed of the following raw materials: 65 parts by weight of small molecule polyacid, 40 parts by weight of alkanolamine, 3 parts by weight of catalyst, 0.4 parts by weight of chelating agent, 0.25 parts by weight of phase transfer catalyst, and 0.3 parts by weight of antioxidant.

[0025] The reinforcing effect of the synthesized product in Example 2 on concrete was verified, and the results are shown in Table 2.

[0026] Table 2

[0027] Example 3 The difference between Example 3 and Example 1 is as follows: Example 3 provides a concrete reinforcing agent, which, by weight, is composed of the following raw materials: 67 parts by weight of small molecule polyacid, 45 parts by weight of alkanolamine, 4 parts by weight of catalyst, 0.5 parts by weight of chelating agent, 0.3 parts by weight of phase transfer catalyst, and 0.4 parts by weight of antioxidant.

[0028] The reinforcing effect of the synthesized product in Example 3 on concrete was verified, and the results are shown in Table 3.

[0029] Table 3

[0030] Example 4 The difference between Example 4 and Example 1 is as follows: The small molecule polyacid in Example 4 is one of citric acid, tartaric acid, succinic acid, glutaric acid, and malic acid; the alkanolamine is one of ethanolamine and diethanolamine; the catalyst is one of sodium ethoxide and sodium hydroxide; and the antioxidant is one of 2,6-di-tert-butyl-p-methylphenol and butyl hydroxyanisole.

[0031] The reinforcing effect of the synthesized product in Example 4 on concrete was verified, and the results are shown in Table 4.

[0032] Table 4

[0033] Example 5 The difference between Example 5 and Example 1 is as follows: The small molecule polyacid described in Example 5 is a mixture of any two of citric acid, tartaric acid, succinic acid, glutaric acid, and malic acid. Preferably, it consists of 30 parts citric acid and 30 parts tartaric acid.

[0034] The reinforcing effect of the synthesized product in Example 5 on concrete was verified, and the results are shown in Table 5.

[0035] Table 5

[0036] Example 6 The difference between Example 6 and Example 1 is: The small molecule polyacid described in Example 6 is a mixture of any three of the following: citric acid, tartaric acid, succinic acid, glutaric acid, and malic acid. Preferably, the mixture contains 20 parts citric acid, 30 parts tartaric acid, and 14 parts succinic acid. The reinforcing effect of the synthesized product in Example 6 on concrete was verified, and the results are shown in Table 6.

[0037] Table 6

[0038] Example 7 The difference between Example 7 and Example 1 is as follows: The small molecule polyacid described in Example 7 is a mixture of any four of the following: citric acid, tartaric acid, succinic acid, glutaric acid, and malic acid. Preferably, the mixture contains 20 parts citric acid, 30 parts tartaric acid, 10 parts succinic acid, and 10 parts glutaric acid.

[0039] The reinforcing effect of the synthesized product in Example 7 on concrete was verified, and the results are shown in Table 7.

[0040] Table 7

[0041] The basic principle of this invention is as follows: the carboxylic acid group reacts with the amine group to generate an amide group, for example, R-COOH+NH-R=R-CON-R+H2O. The synthesized molecule has multiple hydroxyl and amide groups at the same time, which greatly enhances the complexing ability of the molecule, promotes the dissolution of calcium, iron and aluminum ions in cement, thereby promoting the increase of hydration products and effectively improving the mechanical properties of cement.

[0042] In this invention, each molecule of the small-molecule polybasic acid contains multiple carboxyl groups, which can promote the formation of multiple amide groups. The amino group in the alkanolamine reacts with the carboxyl group to form an amide group, and simultaneously introduces a hydroxyl group, enhancing the complexation ability of the synthesized product. The catalyst acts as a catalyst to promote the formation of amide groups. Disodium EDTA reacts with any heavy metal ions that may be present in the reaction system, shielding the adverse effects of heavy metal ions on the synthesis reaction. The phase transfer catalyst promotes the rapid reaction of the polybasic acid and alkanolamine at the two-phase interface by transferring ionic reactants from the aqueous phase to the organic phase. The antioxidant prevents the oxidation of the generated amide groups.

[0043] The advantages of this invention compared to the prior art are as follows: It uses small-molecule polyacids and alcohol amines as the main raw materials, and the product has good water solubility and is easy to use; the dosage is only a few ten-thousandths, so the dosage is small and the cost is controllable; the strengthening effect is significant, and it can improve the early and late strength of concrete at the same time; there are no chloride salts present, so it has no corrosive effect on steel bars, etc.

[0044] Because the synthesized product contains multiple hydroxyl and amide groups, its complexing ability is significantly enhanced, promoting the dissolution of calcium and aluminum ions in cement clinker and accelerating the hydration reaction of cement. This significantly increases the amount of hydration products, thus effectively improving the strength of concrete. Simultaneously, the reaction products contain both hydrophilic and hydrophobic groups, exhibiting the characteristics of surfactants. They can form good adsorption and dispersion effects on the surface of cement particles, allowing for more complete cement hydration, significantly improving the degree of cement hydration, and promoting the improvement of concrete mechanical properties.

[0045] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A concrete reinforcing agent, characterized in that, The product is composed of the following raw materials in parts by weight: 60-70 parts by weight of small molecule polyacids, 30-45 parts by weight of alkanolamines, 1-4 parts by weight of catalysts, 0.3-0.5 parts by weight of chelating agents, 0.1-0.3 parts by weight of phase transfer catalysts, and 0.2-0.5 parts by weight of antioxidants.

2. The concrete reinforcing agent according to claim 1, characterized in that, The small molecule polyacids include one or a mixture of several of citric acid, tartaric acid, succinic acid, glutaric acid, and malic acid.

3. The concrete reinforcing agent according to claim 2, characterized in that, The small molecule polyacids include 15 parts citric acid, 15 parts tartaric acid, 15 parts succinic acid, 10 parts glutaric acid, and 10 parts malic acid.

4. The concrete reinforcing agent according to claim 1, characterized in that, The alkanolamine includes one or a mixture of two of ethanolamine and diethanolamine.

5. A concrete reinforcing agent according to claim 4, characterized in that, The amount of ethanolamine is 15 parts and the amount of diethanolamine is 25 parts.

6. A concrete reinforcing agent according to claim 1, characterized in that, The catalyst is one or a mixture of two of sodium ethoxide and sodium hydroxide.

7. A concrete reinforcing agent according to claim 1, characterized in that, The chelating agent is disodium EDTA.

8. A concrete reinforcing agent according to claim 1, characterized in that, The phase transfer catalyst is tetrabutylammonium bromide.

9. A concrete reinforcing agent according to claim 1, characterized in that, The antioxidant is one or a mixture of two of 2,6-di-tert-butyl-p-methylphenol and butylated hydroxyanisole.

10. A method for preparing a concrete reinforcing agent according to any one of claims 1-9, characterized in that, include: The catalyst is dissolved in ultrapure water to prepare a 5-10% solution, which is then stored in a nitrogen-protected, sealed container. Weigh the alcoholamine and store it in a sealed container for later use; Prepare a 50% solution of the small molecule polyacid using distilled water; In a reactor equipped with temperature control, stirring and reflux condensation devices, a small molecule polyacid solution and a metal ion chelating agent are added to construct a primary reaction system. The primary reaction system was heated to 40-50℃ and stirred at 200 rpm for 30 min, followed by the addition of a phase transfer catalyst; The temperature was controlled at 40-50℃. The catalyst solution and amine were simultaneously added dropwise to the primary reaction system using a dual-channel precision metering pump. The initial dropping rate was controlled at 0.5 mL / min and continued for 10 min. Increase the temperature to 75-80℃ at a rate of 0.5℃ / min, increase the dropping rate to 1 mL / min, and continue for 20 min. During this period, adjust the dropping rate of the metering pump to maintain the pH at 8.5-9.

5. Heat the mixture to 90±5℃, add the remaining raw materials dropwise within 30 minutes, and then maintain the temperature for 4 hours after the reaction is complete. After the reaction is complete and cooled to room temperature, an antioxidant is added, and stirring is continued for 10 minutes to obtain the concrete reinforcing agent.

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