High-performance concrete corrosion inhibitor and reinforcing agent, preparation method and application thereof

Abstract

The application discloses a high-performance concrete anticorrosion reinforcing agent, a preparation method and application, and belongs to the field of concrete additives. The high-performance concrete anticorrosion reinforcing agent is composed of modified nanometer materials with a filling effect, alkyl alcohol amine and a hydroxyl compound; the modified nanometer materials are nanometer materials treated by an organic modifier on the surface; and the organic modifier is organosiloxane or an organic carboxylic acid or a combination of the two. The organosiloxane is connected with the nanometer materials through a silicon alcohol bond, and the organic carboxylic acid is physically adsorbed on the surface of the nanometer materials. Through the combination of the modified nanometer materials and alcohol amine hydration regulation materials, the microstructure of the concrete can be optimized and improved, the pore compactness of the concrete can be effectively optimized and improved, the concrete can be resistant to corrosion, freezing and carbonization, and the durability of the concrete can be achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of concrete additives, and particularly relates to a high-performance concrete corrosion-resistant reinforcing agent, a preparation method and application. BACKGROUND

[0002] Reinforced concrete is widely used in infrastructure construction, but the long service life and high durability of concrete is still a difficult problem that has not been solved, especially for concrete under severe service environment, the problems of poor sulfate corrosion resistance, poor frost resistance, serious carbonization, shrinkage cracking and the like are more prominent, which brings immeasurable loss to the national economy and people's life and property safety. Improving and enhancing the corrosion resistance of concrete itself has become an effective way to ensure the service safety and life guarantee of major infrastructure projects.

[0003] For the sulfate corrosion of concrete, the current research believes that the compactness of concrete itself should be improved, and the main technical means includes reducing the water-binder ratio and using mineral admixtures; reducing the water-binder ratio and reducing the water consumption will greatly affect the workability of fresh concrete; the use of mineral admixtures such as fly ash, mineral powder and silica ash may cause the early strength of concrete to be low, the carbonization depth to be increased and the risk of shrinkage cracking to be increased; the above conventional technical means mainly reduces the number of pores and optimizes the pore structure to reduce the transmission path of the erosive ions. However, in the actual environment, the sulfate corrosion damage is a process of continuous corrosion from the surface of the concrete to the inside of the concrete, and the process of relatively fast corrosion rate is the cracking and pulverization of the cementitious material system itself caused by sulfate crystallization damage, which loses the cementation. Simply improving the compactness of concrete has certain limitations in improving the sulfate corrosion resistance of concrete, unless the water-binder ratio of concrete is reduced to the extreme, so that the performance of concrete reaches the performance level of ultra-high performance concrete, the sulfate corrosion resistance of concrete will be significantly improved, otherwise for general low-strength concrete, using conventional compactness technical means, the effect of improving and enhancing the corrosion resistance of concrete is relatively weak. In recent years, with the continuous deepening of research, new types of nanomaterials have been developed, and some have been applied to engineering practice. For example, patent CN105330194B reports that a nano-suspension can be used as a concrete early compactness, strength improvement and erosion inhibition material, but such nano-materials have an impact on the long-term corrosion resistance of concrete. Although there are patents (CN105601162A) that some new types of nanomaterials and hydrophobic organosilane combined materials can optimize and enhance the corrosion resistance of concrete, but the dispersion of the combined material itself is poor and has a great impact on the early performance, which leads to the fact that the long-term corrosion resistance of the combined material to concrete is still not significant in practical application, and the improvement of the corrosion resistance of concrete is mostly due to the hydrophobicity of organosilane, which enhances the ability of concrete to resist medium penetration, but the long-term corrosion resistance of organosiloxane needs to be verified over time.

[0004] In addition, some combination of concrete water-reducing, densification, crack resistance, and steel rust resistance components is also the main direction of the development of concrete corrosion-resistant reinforcing products. For example, patent CN101475334A reports a composite concrete corrosion inhibitor, which is composed of water-reducing and reinforcing components, cathodic steel rust resistance components, air entraining and densification components, etc. The water-reducing, reinforcing and densification components are all common raw materials, and the main effects can be achieved through the application of concrete proportioning control and mineral admixtures. Patents US6340438, US5527388, US006174461 B1, US006342101 B1, CN201210099558.0 report inorganic salts and low molecular weight (alcohol) amine mixtures as concrete additives for corrosion inhibition of steel reinforcement in reinforced concrete structures, but less mention of the influence of such substances on the performance of concrete, especially on the corrosion resistance of concrete. Nmai CK, based on the study of simple alcohol amine type steel corrosion inhibitor (cement concrete composites, 2004, 26, 199-207), proposed a multifunctional steel corrosion inhibitor for reinforced concrete, in which lauric acid acyl sarcosine organic acid was used for structural modification to prepare a multifunctional corrosion-resistant concrete additive with concrete sulfate corrosion resistance and steel corrosion resistance. The specific mechanism is still not clear, and it is speculated that the main corrosion prevention effect is due to the reaction of lauroyl sarcosine with calcium ions in concrete to generate hydrophobic substances to inhibit concrete corrosion. However, lauroyl sarcosine has strong surface activity in practical application, and the dosage is generally high to achieve the effect of corrosion prevention, which can easily lead to the introduction of more air bubbles in the concrete system, resulting in poor concrete density and deterioration of long-term corrosion resistance of concrete. SUMMARY

[0005] Reinforced concrete has the problems of poor sulfate corrosion resistance, poor frost resistance, and serious carbonization in severe service environments, making it more difficult to ensure the durability of concrete; improving the density of concrete itself and adding anti-erosion inhibitors in concrete are effective ways to improve and enhance the durability of concrete itself, but conventional densification techniques have relatively weak effects on improving and enhancing the corrosion resistance of concrete, and existing anti-erosion inhibitors cannot guarantee the durability of concrete. In view of the above problems, the present application provides a high-performance concrete corrosion-resistant reinforcing agent, which combines modified nanomaterials with alcohol amine hydration control materials to optimize and enhance the microstructure of concrete, effectively optimize and improve the pore density of concrete, achieve corrosion resistance, frost resistance, and carbonization resistance of concrete, and achieve the durability of concrete.

[0006] The high-performance concrete corrosion-resistant reinforcing agent is composed of modified nanomaterials with filling effect, alkyl alcohol amine and hydroxyl compounds, and the mass percentage of each component is:

[0007] Modified nanomaterials: 4%-50%

[0008] Alkyl alcohol amine: 2%-20%

[0009] Polyhydroxy compound: 0.01%-5%

[0010] Water: balance

[0011] The sum of the mass percentages of the above components is 100%.

[0012] Further preferably, the mass percentage of the modified nanomaterials is 4%-8%, the mass percentage of the alkyl alcohol amine is 6%-12%, and the mass percentage of the polyhydroxy compound is 0.1%-3%. Preferably, the composition and ratio of each material are considered in combination with the utilization rate of the modified material, application cost, etc., and are also optimized according to the dense filling performance and modification effect.

[0013] The modified nanomaterials are nanomaterials treated with an organic modifier on the surface; the organic modifier is an organosiloxane or an organic carboxylic acid or a combination of the two. The organosiloxane is connected to the nanomaterial through a silicon alcohol bond, and the organic carboxylic acid is physically adsorbed on the surface of the nanomaterial.

[0014] The mass ratio of the organic modifier to the nanomaterial is 1:1-300.

[0015] The nanomaterials are one or a combination of nanosilica, nanoalumina, and nanocopper oxide, and the particle size of the nanomaterials ranges from 5-1000 nm.

[0016] The organic carboxylic acid is a fatty acid or an aromatic carboxylic acid with a carbon atom number of 1-20.

[0017] The organosiloxane is a methoxysiloxane or an ethoxysiloxane with a carbon atom number of 1-20.

[0018] The modification of the surface of the nanomaterial by the organic carboxylic acid is mainly achieved by physical adsorption, while the organic siloxane can form a firm chemical bond with the hydroxyl group on the surface of the nanomaterial through the silanol bond, thereby achieving the effect of physical adsorption and chemical bonding. The physical adsorption and chemical bonding can better control the active release time of the nanomaterial, and at the same time, after the modification of the nanomaterial by the organic acid or the siloxane, the physical properties of the surface of the nanomaterial change, and a certain hydrophobicity is generated on the surface; at the same time, the coverage of the organic acid or the siloxane forms a single molecular layer protective film on the surface of the nanomaterial, so that the activity of the nanomaterial is inhibited to a certain extent, thereby truly playing the effect of the nanomaterial in the later stage of pore densification and improving the long-term corrosion resistance of the concrete.

[0019] The coverage and density of the surface adsorption layer can be improved by the regulation of the molecular structure of the organic carboxylic acid or the organic siloxane, thereby achieving the expected modification effect, and the nanomaterial with different hydrophobicity improvement effects can be achieved by adjusting the length of the alkyl or aryl molecular chain, and the difference in the effect of hydrophobicity improvement will cause the microstructure and corrosion resistance of the hydration product to change, thereby achieving the targeted corrosion prevention requirement.

[0020] Further, the organic siloxane is a methoxy or ethoxy siloxane with a carbon atom number of 4-12, and the regulation of the molecular chain length can achieve the adjustment of the structure adsorption arrangement order and the density, thereby realizing the regulation of the release rate of the nanoparticles.

[0021] The alkyl alcohol amine is one of ethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, N-methylethanolamine, N-methyl diethanolamine, ethylene glycol monoisopropanolamine, triisopropanolamine, and N,N,N,N-tetrahydroxyethyl ethylenediamine, and a combination of several thereof.

[0022] The alkyl alcohol amine compound can regulate the cement hydration performance, and in combination with the nanomaterial, better realizes the effectiveness of filling and densification of the nanomaterial in the process of densifying the pores of the concrete. The alkyl alcohol amine compound and the nanomaterial modification material jointly act to realize the further regulation and improvement of the later stage hydration process of the cement.

[0023] The polyhydroxy compound is one of cellulose ether, polyvinyl alcohol, cyclodextrin, chitosan, xanthan gum, and valen gum, or a combination of several thereof. The molecular weight of the cellulose ether is 100-1000 million. The molecular weight of the polyvinyl alcohol is 50-1000 million. The cyclodextrin is alpha, beta or gamma cyclodextrin. The chitosan has a molecular weight of 100-1000 million. The xanthan gum or valen gum is a commonly used biological glue on the market.

[0024] The application also provides a preparation method of the high-performance concrete corrosion-resistant reinforcing agent, specifically including the following steps:

[0025] (1) After acidizing the nanomaterial, an organic modifier is added, and the nanomaterial and the organic modifier are uniformly mixed by atomization mixing treatment at 60-300 DEG C to obtain a modified nanomaterial;

[0026] (2) Water, an alkyl alcohol amine and a polyhydroxy compound are added to a reaction kettle, and the mixture is uniformly mixed, and then the modified nanomaterial of step (1) is added, and the pH of the solution is controlled at 5-9, and after the system is stable, a high-performance concrete corrosion-resistant enhancer is obtained.

[0027] The acid for acidizing in step (1) is one of hydrochloric acid, nitric acid and phosphoric acid.

[0028] The application of the high-performance corrosion-resistant enhancer of the application is different from that of a general corrosion inhibitor, the high-performance corrosion-resistant enhancer is a nanomaterial water dispersion system, the nanomaterial water dispersion system is convenient to use, and there is no dust pollution in the production and application process, and the dispersion of the nanomaterial is improved in advance in the water dispersion system, so that the application in the concrete system is facilitated. The use of the hydroxy compound in the application mainly improves the stability of the nanomodified material in the water dispersion system, and the selected hydroxy compound is mainly a polyhydroxy compound with a large molecular weight, which has certain thickening and water locking properties, can lock the dispersion of the nanomaterial in water, and reduces the collision of the nanomaterial itself to generate aggregation, agglomeration, gelation, stratification and other uneven dispersion problems.

[0029] The beneficial effects of the high-performance corrosion-resistant enhancer of the application mainly include the following aspects:

[0030] 1. The high-performance concrete corrosion-resistant enhancer of the application uses a nanomaterial as a main corrosion-resistant enhancing material, the nanomaterial has a dense filling effect, can effectively optimize and improve the pore density of concrete, and in addition, the nanomaterial is modified by an organic carboxylic acid and an organosiloxane, and the problems of poor dispersion of ordinary nanomaterials in concrete, simple use as a crystal seed to only promote early hydration and poor improvement of long-term durability of concrete are effectively solved.

[0031] 2. The nanomaterial is modified by physical adsorption and chemical bonding on the surface, and the activity release time of the nanomaterial can be well controlled, the physical adsorption of the organic carboxylic acid is relatively short in general, the nanomaterial surface is exposed to the water reaction product for a relatively short time, and the nanomaterial surface is exposed and the surface reacts for a longer time after chemical bonding, so that the combination of short-term and long-term performance of the nanomaterial is realized, and the effective improvement and promotion of the corrosion resistance of the concrete in the whole life cycle are achieved.

[0032] 3. By selecting and combining different alkyl or aryl chain lengths of the organic carboxylic acid or the organosiloxane, the overall corrosion resistance of the concrete can be finally improved.

[0033] 4. The alkyl alcohol amine compound and the nano-modified material jointly act, realize further regulation and perfection of cement later hydration process, and further improve effectiveness of filling and densification of nano material in dense concrete pore process.

[0034] 5. The preparation process is simple and convenient to implement, and the prepared product has green environmental protection, high efficiency and other characteristics, and is very suitable for corrosion protection of reinforced concrete structure in salt and alkali land, ocean and other complex harmful ion erosion environments. DETAILED DESCRIPTION

[0035] The application will be described in detail below through examples, which are only illustrative and do not represent limitation of the application scope, and those skilled in the art can make changes to reagents, catalysts and reaction process conditions within the scope of the application according to the disclosure herein. Equivalent changes or modifications made according to the spirit and principle of the application should be covered within the protection scope of the application.

[0036] Example 1

[0037] The 5g 10nm-sized silicon dioxide is subjected to acidification treatment in a 0.01mol / L hydrochloric acid system, 1g of dodecyl triethoxysilane and 1g of acetic acid are added after the treatment, and the modified nano-silicon dioxide is prepared by atomization mixing treatment under the condition of 120 DEG C.

[0038] 85g of water, 10g of N-methyldiethanolamine and 0.2g of cellulose ether (molecular weight 2 million) are added into a reaction kettle, stirred uniformly, the modified nano-silicon dioxide is added into the above water solution, the pH in the solution is controlled to be 5-9, and fast stirring is carried out, after the nano-silicon dioxide is added, the stirring is continuously carried out until the system is stable, and the prepared high-performance concrete corrosion-resistant reinforcing agent is obtained.

[0039] Example 2

[0040] The 30g 50nm-sized silicon dioxide is subjected to acidification treatment in a 0.01mol / L hydrochloric acid system, 6g of lauric acid is added after the treatment, and the lauric acid-modified nano-silicon dioxide is obtained by atomization mixing treatment under the condition of 200 DEG C.

[0041] 80g of water, 5g of ethanolamine and 0.5g of waring gum (molecular weight 10 million) are added into a reaction kettle, stirred uniformly, the modified nano-silicon dioxide is added into the above water solution, the pH in the solution is controlled to be 5-9, and fast stirring is carried out, after the nano-silicon dioxide is added, the stirring is continuously carried out until the system is stable, and the prepared high-performance concrete corrosion-resistant reinforcing agent is obtained.

[0042] Example 3

[0043] The alumina trioxide with a particle size of 20-30 nm is acidized in a 0.01 mol / L nitric acid system, 0.5 g of n-butyl trimethoxysilane and 2 g of octanoic acid are added after the treatment, and the mixture is treated by atomization at 80°C to obtain modified nano-silica.

[0044] The reaction kettle is added with 80 g of water, 25 g of triethanolamine and 0.6 g of cellulose ether (molecular weight 2 million), the mixture is stirred uniformly, the modified nano-silica is added into the above water solution, the pH of the solution is controlled at 5-9, the mixture is stirred rapidly, and after the addition of the nano-silica is completed, the stirring is continued until the system is stable to obtain the prepared high-performance concrete corrosion-resistant reinforcing agent.

[0045] Example 4

[0046] The alumina trioxide with a particle size of 100 nm is acidized in a 0.01 mol / L hydrochloric acid system, 5 g of sunflower acid is added after the treatment, and the mixture is treated by atomization at 180°C to obtain modified nano-silica.

[0047] The reaction kettle is added with 50 g of water, 15 g of N,N,N,N-tetrahydroxyethyl ethylenediamine and 0.05 g of xanthan gum (molecular weight 5 million), the mixture is stirred uniformly, the modified nano-silica is added into the above water solution, the pH of the solution is controlled at 5-9, the mixture is stirred rapidly, and after the addition of the nano-silica is completed, the stirring is continued until the system is stable to obtain the prepared high-performance concrete corrosion-resistant reinforcing agent.

[0048] Example 5

[0049] The copper oxide with a particle size of 500 nm is acidized in a 0.01 mol / L hydrochloric acid system, 3 g of octanoic acid is added after the treatment, and the mixture is treated by atomization at 100°C to obtain modified nano-silica.

[0050] The reaction kettle is added with 40 g of water, 20 g of triisopropanolamine and 0.05 g of cyclodextrin (molecular weight 5 million), the mixture is stirred uniformly, the modified nano-silica is added into the above water solution, the pH of the solution is controlled at 5-9, the mixture is stirred rapidly, and after the addition of the nano-silica is completed, the stirring is continued until the system is stable to obtain the prepared high-performance concrete corrosion-resistant reinforcing agent.

[0051] Example 6

[0052] The copper oxide with a particle size of 10 nm is acidized in a 0.01 mol / L nitric acid system, 0.5 g of oleic acid is added after the treatment, and the mixture is treated by atomization at 240°C to obtain modified nano-silica.

[0053] Into a reaction kettle, 70 g of water, 10 g of dimethyl ethanolamine and 0.02 g of chitosan (molecular weight 10 million) were added, stirred uniformly, then the modified nano-silica was added into the above water solution, the pH of the solution was controlled at 5-9, fast stirring, after the nano-silica was added, the stirring was continued until the system was stable, and the prepared high-performance concrete corrosion-resistant reinforcing agent was obtained.

[0054] Example 7

[0055] 20 g of nano-silica with a particle size of 800 nm was acidized in a 0.01 mol / L hydrochloric acid system, then 0.6 g of hexadecyl triethoxysiloxane was added, and the mixture was treated by atomization at 280°C, and the modified nano-silica was obtained through the surface modification process.

[0056] Into a reaction kettle, 70 g of water, 10 g of dimethyl ethanolamine and 0.02 g of chitosan (molecular weight 10 million) were added, stirred uniformly, then the modified nano-silica was added into the above water solution, the pH of the solution was controlled at 5-9, fast stirring, after the nano-silica was added, the stirring was continued until the system was stable, and the prepared high-performance concrete corrosion-resistant reinforcing agent was obtained.

[0057] Comparative Example 1

[0058] This comparative example is based on Example 1, and the difference from Example 1 is that the nano-material is not modified.

[0059] The particle size of 5 g of 10 nm silica was acidized in a 0.01 mol / L hydrochloric acid system.

[0060] Into a reaction kettle, 70 g of water, 10 g of dimethyl ethanolamine and 0.02 g of chitosan (molecular weight 10 million) were added, stirred uniformly, then the modified nano-silica was added into the above water solution, the pH of the solution was controlled at 5-9, fast stirring, after the nano-silica was added, the stirring was continued until the system was stable, and the prepared high-performance concrete corrosion-resistant reinforcing agent was obtained.

[0061] Application Example

[0062] The concrete durability performance test was carried out on the samples of the above examples and comparative examples according to GB / T 50082 "Standard for Testing Methods of Long-term Performance and Durability of Ordinary Concrete", mainly investigating the influence of different samples on the concrete anti-sulfate corrosion performance, carbonation resistance and freeze-thaw resistance, wherein the concrete W / C is 0.40, the cement is ordinary Portland cement (Hailuo P.O. 42.5), the sand is river sand, the stone is basalt, the particle size range is 5-15 mm and 10-25 mm, the sand rate is 0.39; the concrete corrosion-resistant enhancer content is 10% of the cementitious material, and the water is deducted by equal amount in the application process, the reference group is the concrete without adding the high-performance concrete corrosion-resistant enhancer, and the experimental results are shown in the following table.

[0063] Table 1 Influence of different comparative examples and examples on the mechanical properties and corrosion resistance of concrete

[0064]

[0065] The results in the table show that the high-performance concrete corrosion-resistant enhancer can significantly improve the sulfate corrosion resistance of concrete, reduce the carbonation depth of concrete, enhance the freeze-thaw cycle times of concrete, effectively improve the durability of concrete structure, enhance the corrosion resistance of concrete, and prolong the service life of the structure.

Claims

1. A high performance concrete corrosion inhibitor and strength enhancer, characterized in that, The components are composed of the following mass percentages: Modified nanomaterial: 4%-50%, Alkyl alcohol amine: 2%-20%, Polyhydroxy compound: 0.01%-5%, Water: the balance, The sum of the mass percentages of the above components is 100%; The modified nanomaterial is a nanomaterial treated with an organic modifier on the surface; the organic modifier is an organosiloxane or an organic carboxylic acid or a combination of the two; the organic carboxylic acid is a fatty acid or an aromatic carboxylic acid with a carbon atom number of 1-20; the organosiloxane is a methoxy or ethoxy siloxane with a carbon atom number of 1-20; the nanomaterial is one or a combination of several of nanosilica, nanoalumina, and nanocopper oxide; The polyhydroxy compound is one or a combination of several of cellulose ether, polyvinyl alcohol, cyclodextrin, chitosan, xanthan gum, and welan gum.

2. The high performance concrete corrosion inhibitor and strength enhancer of claim 1, wherein, The mass percentage of the modified nanomaterial is 4%-8%, the mass percentage of the alkyl alcohol amine is 6%-12%, and the mass percentage of the polyhydroxy compound is 0.1%-3%.

3. The high performance concrete corrosion inhibitor and strength enhancer of claim 1, wherein, The mass ratio of the organic modifier to the nanomaterial is 1:1-300.

4. The high performance concrete corrosion inhibitor and strength enhancer of claim 1, wherein, The particle size range of the nanomaterial is 5-1000 nm.

5. The high performance concrete corrosion inhibitor and strength enhancer of claim 1, wherein, The organosiloxane is a methoxy or ethoxy siloxane with a carbon atom number of 4-12.

6. The high performance concrete corrosion inhibiting and reinforcing admixture of claim 1, wherein The alkyl alcohol amine is one or a combination of several of ethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, N-methylethanolamine, N-methyl diethanolamine, ethylene glycol monoisopropanolamine, triisopropanolamine, and N,N,N,N-tetrahydroxyethyl ethylenediamine.

7. The high performance concrete corrosion inhibitor and enhancer of claim 1, wherein The cellulose ether has a molecular weight of 100-1000 million; the polyvinyl alcohol has a molecular weight of 50-1000 million; the cyclodextrin is α, β, or γ cyclodextrin; and the chitosan has a molecular weight of 100-1000 million.

8. The method of producing the high performance concrete corrosion enhancing additive according to any one of claims 1 to 7, characterized in that, Specifically includes the following steps: (1) After acidizing the nanomaterial, adding an organic modifier, and performing atomization mixing treatment at 60-300°C, the nanomaterial and the organic modifier are mixed uniformly to obtain the modified nanomaterial; (2) Adding water, alkyl alcohol amine, and polyhydroxy compound to a reaction kettle, mixing uniformly, then adding the modified nanomaterial of step (1), controlling the pH of the solution to be 5-9, and after the system is stable, a high-performance concrete corrosion-resistant enhancer is obtained.

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