Prefabricated part concrete reinforcement corrosion-resistant material as well as preparation method and application thereof

Abstract

The invention relates to the field of building materials and the field of concrete admixtures, in particular to a prefabricated part concrete reinforcement corrosion-resistant material and a preparation method and application thereof. The corrosion-resistant material is prepared from raw materials including a reinforcing steel bar corrosion-resistant component modified by nano-particles on the surface and a heterocyclic compound, the reinforcing steel bar corrosion-resistant component modified with the nano-particles on the surface is prepared from raw materials including compound amino alcohol, siloxane and a nano-material, the compound amino alcohol is prepared by addition of primary / secondary amine with the carbon atom number of 2-6 and ethylene oxide / propylene oxide, and the number of hydroxyl groups of the compound amino alcohol is 1-3; the problems that when an existing steel bar corrosion inhibitor is applied to prefabricated part concrete, early mechanical property development under the steam curing condition is affected, volatilization dissipation and decomposition exist in high-temperature steam curing, and long-term durability of concrete is affected can be solved.

Description

Technical Field

[0001] This application relates to the field of concrete admixtures in the field of building materials. More specifically, it relates to a corrosion inhibitor for steel bars in precast concrete components, its preparation method and applications. Background Art

[0002] Precast concrete components are building components prefabricated in factories with concrete as the basic material, including beams, slabs, columns, segments, pipe piles and building decoration accessories, etc. With the global warming and increasingly harsh environmental changes, submarine tunnel structures and coastal pile foundation projects represented by segments and pipe piles are facing more and more severe material property deterioration and environmental tests, and the problem of steel bar corrosion in component concrete is becoming more and more prominent.

[0003] As one of the effective technical measures to improve the corrosion inhibition performance of steel bars in structural concrete, corrosion inhibitors for steel bars are widely used worldwide due to their low application cost, convenient use and high efficiency. Corrosion inhibitors for steel bars inhibit the contact between corrosive media and the steel bar matrix by forming a dense oxide film and an adsorption film on the surface of the steel bars, thereby achieving the effect of corrosion inhibition of steel bars. Incorporating corrosion inhibitors during the concrete mixing process is a common application method of corrosion inhibitors. Representative incorporated corrosion inhibitors are inorganic nitrites and organic carboxylamines, etc. The most representative ones are inorganic nitrites and organic carboxylamines, etc. Since nitrosamines are carcinogenic and low contents can cause accelerated local corrosion, the United States and some European countries have clearly prohibited their use. Although a large number of patents have been applied for around carboxylamines, amino alcohols, etc. in recent years, such as patents US6340438, US5527388, US006174461B1, US006342101B1, CN201210099558.0 are all mixtures of inorganic salts and low molecular weight (alcohol) amines as corrosion inhibitors for steel bars, however, the application effects of such corrosion inhibitors in actual projects have gradually been proven to be relatively limited.

[0004] CN 117777431 A discloses a hydrophobic functionalized corrosion inhibitor for steel bars, which realizes the functional enhancement of the corrosion inhibitor through the regulation of the molecular structure of the corrosion inhibitor, and the anti-dissipation and long-term corrosion resistance performance are significantly enhanced. CN 113831058B also reports a nano-hydrophobic corrosion inhibitor and its preparation method. The corrosion inhibitor for steel bars uses polyaspartic acid and a cathodic corrosion inhibitor to synergistically strongly adsorb on the surface of the steel bars to protect the steel bars, adds nano-particles to densify the pores of the concrete, ensures the effective concentration of the corrosion inhibitor during the long-term service of the structure, effectively delays the depassivation time of the concrete steel bars, reduces the steel bar corrosion rate, and realizes the improvement and guarantee of the durability of the concrete. The above corrosion inhibitors for steel bars are mainly applied in ready-mixed concrete and can be directly mixed for engineering construction. The workability and other properties can be regulated through water reducers and other admixtures.

[0005] However, in the precast concrete component system, the current application of corrosion inhibitors is still not widespread. Especially for the concrete of segment linings, pipe piles and other similar precast components, due to the need for efficient turnover of products and improvement of production efficiency in factory prefabrication, the concrete of precast components such as segment linings and pipe piles will accelerate the formation of segment concrete through methods such as steam curing. The steam curing process requires heating up, accelerating the early hydration of cement, and promoting the improvement of early strength. However, there are still the following technical problems in the application of existing steel bar corrosion inhibitors in the precast concrete structure system:

[0006] (1) It affects the early hydration of cement, resulting in a decrease in early mechanical properties under steam curing conditions and affecting production efficiency. For example, amino alcohol-based organic corrosion inhibitors, especially polyhydroxy amino alcohols, due to their strong adsorption characteristics, while adsorbing on the surface of steel bars, will also partially remain and adsorb on the surface of cement particles, thus affecting cement hydration. During the steam curing process, it will cause a decline in the early mechanical properties of precast components, and it is difficult for the later strength to develop further.

[0007] (2) Amino alcohol-based organic corrosion inhibitors will volatilize during the high-temperature steam curing process, and with the increase in steam curing temperature, the volatilization rate accelerates, resulting in the loss of effective corrosion inhibition components in the concrete, thus affecting the long-term corrosion inhibition effect of steel bars.

[0008] (3) When using inorganic nitrite corrosion inhibitors during steam curing, there is also an accelerated decomposition of effective components, resulting in insufficient long-term performance of steel bar corrosion inhibition. Moreover, the high toxicity and carcinogenicity of nitrites will also limit their application.

[0009] In some segment linings or pipe pile concretes in the steam curing system where steel bar corrosion inhibitors that affect the early hydration of cement are applied, it will cause a decrease in the chloride ion penetration resistance of the concrete, thus affecting the long-term durability of precast concrete structures. Summary of the Invention

[0010] In order to solve the problems existing in the application of existing steel bar corrosion inhibitors in precast concrete components, such as affecting the development of early mechanical properties under steam curing conditions, volatilization dissipation, decomposition during high-temperature steam curing, and affecting the long-term durability of concrete, this application provides a steel bar corrosion inhibitor material for precast concrete components, its preparation method and application.

[0011] In the first aspect, this application provides a steel bar corrosion inhibitor material for precast concrete components, adopting the following technical solution:

[0012] A steel bar corrosion inhibitor material for precast concrete components, the corrosion inhibitor material is composed of raw materials including a steel bar corrosion inhibition component with surface modification of nanoparticles and a heterocyclic compound, and the weight ratio of the steel bar corrosion inhibition component with surface modification of nanoparticles to the heterocyclic compound is 1:(0.001 - 0.05);

[0013] The steel bar rust inhibitor component with surface modification of nanoparticles is prepared from raw materials including compound amino alcohol, siloxane and nanomaterials. The weight ratio of the compound amino alcohol, siloxane and nanomaterials is 1:(0.01-0.5):(0.1-0.5). The compound amino alcohol is prepared by adding ethylene oxide / propylene oxide to primary / secondary amine with 2-6 carbon atoms, and the number of hydroxyl groups of the compound amino alcohol is 1-3.

[0014] By adopting the above technical solution, in the steel bar rust inhibitor component with surface modification of nanoparticles of the present application, the appropriate number of carbon atoms of the compound amino alcohol enables it to have good solubility, and can form a dynamically adsorbed film layer on the surface of the steel bar. After adsorbing on the surface of the steel bar, it can significantly enhance the hydrophobicity of the steel bar surface, thereby improving the corrosion resistance of the steel bar under wet-dry cycling conditions. In addition, the appropriate number of hydroxyl groups can improve its adsorption ability on the steel bar surface without leaving too much pore solution, nor adsorbing too much amino alcohol area on the surface of cement particles, thus avoiding the problem of delaying the early hydration of cement and ultimately affecting the early mechanical properties of segment concrete; on the one hand, siloxane is used to modify and decorate the surface of nanoparticles, change the structure and physical and chemical properties of nanoparticles, improve the adaptability of amino alcohol rust inhibitor to cement hydration, and at the same time adsorb a part of the amino rust inhibitor to reduce the loss of rust inhibitor during steam curing; on the other hand, the siloxane-modified nanoparticles themselves have certain characteristics of blocking concrete pores and interfacial hydrophobic modification, which can enhance the anti-medium penetration energy absorption of structural concrete; the particularly beneficial effect is that the nanoparticles modified by surface siloxane can produce rust inhibition synergistic enhancement on the adsorbed steel bar surface, thereby enhancing the corrosion resistance of steel bars in structural concrete, and the effect of improving the rust inhibition performance of steel bars in high-temperature steam curing systems is significant; the nanoparticles have good aqueous solution dispersibility after being modified by amino alcohol, siloxane, etc., can be well dispersed during the concrete mixing process, can accelerate the early hydration of cement, and do not affect the concrete mixing performance; in addition, the nanoparticles can also play a role in blocking the pores of precast concrete components, and the particle size and shape of the nanoparticles have a greater impact on the blocking of concrete pores. The heterocyclic compound is mainly used for the pitting corrosion resistance of steel bars in precast concrete components, and has a significant effect on the formation of the passive film of steel bars and the inhibition of micro-area pitting.

[0015] Overall, the precast component steel bar rust inhibitor material provided by the present application can be applied to, but is not limited to, precast concrete such as segment linings, pipe piles, and precast box girders. It is mainly used to improve the corrosion resistance of steel bars in precast concrete, and to avoid problems such as the decline in early mechanical properties, the reduction in the chloride ion penetration resistance of concrete, and the volatilization and dissipation of small molecule rust inhibitor materials during high-temperature steam curing caused by the application of ordinary rust inhibitor materials in segment lining concrete; to reduce the negative impacts brought by the application of rust inhibitors to precast component concrete and the problems of insufficient long-term rust inhibition and concrete durability, and to meet the requirements of steel bar rust inhibition and durability improvement of structural concrete in such precast component concrete under severe service environments such as the ocean, undersea tunnels, and saline soil.

[0016] Further, the siloxane includes, but is not limited to, trimethoxy or triethoxysiloxane with an alkyl C atom number of 1 to 18, and amino or glycidyl trimethoxy or triethoxysiloxane with an alkyl C atom number of 1 to 6. Still further, the trimethoxy or triethoxysiloxane with an alkyl C atom number of 1 to 18 includes, but is not limited to: dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, octadecyltrimethoxysilane, n-octyltriethoxysilane, isooctyltriethoxysilane, butyltriethoxysilane, isobutyltriethoxysilane, ethyltriethoxysilane, methyltriethoxysilane, etc.; the amino or glycidyl trimethoxy or triethoxysiloxane with an alkyl C atom number of 1 to 6 includes, but is not limited to: 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-aminoethyl-3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, N,N-dimethyl-3-aminopropyltrimethoxysilane, N,N-diethyl-3-aminopropyltrimethoxysilane; at least one of glycidylmethyltrimethoxysilane, glycidylpropyltriethoxysilane, and glycidyl 2-amino-propyltriethoxysilane.

[0017] Further, the nano material is one or a combination of nano silicon dioxide, nano titanium dioxide, nano calcium carbonate, nano C-S-H particles, and nano silica sol.

[0018] Further, the particle size of the nano material is 10 to 200 nm.

[0019] Further, the particle size of the nano material is 20 to 60 nm. The nano particle size range within 20 to 60 nm has a more excellent synergistic effect of accelerating the early hydration of cement and densely filling the pores of concrete in the later stage.

[0020] Further, the heterocyclic compound is one or a combination of imidazole, thiazole, benzotriazole, and their derivatives, not limited to alkyl substitution or cationic structures. Still further, imidazole, thiazole, or benzotriazole and their derivatives include, but are not limited to: one or several combinations of imidazole, 1-methylimidazole, 2-methylimidazole, triphenylimidazole, 2-mercapto-5-methoxybenzimidazole, thiazole, isothiazolinone, 2-amino-5-methylthiazole, 1,2-benzisothiazol-3-one, benzotriazole, nitrobenzotriazole, aminobenzotriazole, and methylbenzotriazole.

[0021] Further, the raw materials of the rust inhibitor material further include functional aids, and the weight ratio of the steel bar rust inhibitor component modified on the surface of the nanoparticles, the heterocyclic compound, and the functional aids is 1:(0.001 - 0.05):(0.0001 - 0.05).

[0022] Further, the functional aids include one or a combination of an air-entraining agent, an antifoaming agent, or a polycarboxylate water reducer;

[0023] In a second aspect, the present application provides a preparation method for a steel bar rust inhibitor material for precast concrete members, adopting the following technical solution:

[0024] A preparation method for a steel bar rust inhibitor material for precast concrete members includes the following steps: adding amino alcohol and a nanomaterial into a solvent, stirring and dispersing evenly, slowly dropping siloxane at a temperature of 10 - 80°C, with a dropping time of 0.5 - 4 h, and continuing to keep warm and react for 0.5 - 6 h after the dropping is completed to obtain a steel bar rust inhibitor component with a modified surface of nanoparticles, then adding a heterocyclic compound, stirring for 10 - 30 min, and discharging to obtain a steel bar rust inhibitor material for precast concrete members.

[0025] Further, if a functional aid is added, a steel bar rust inhibitor component with a modified surface of nanoparticles is obtained, then a heterocyclic compound and a functional aid are added, stirred for 10 - 30 min, and discharged to obtain a steel bar rust inhibitor material for precast concrete members.

[0026] Further, the solvent is one or a combination of water, ethanol, or toluene.

[0027] By adopting the above technical solution, the preparation process of the present application, in addition to making each component disperse evenly, can effectively control the surface particle modification efficiency and the effect after surface modification by regulating the reaction temperature and reaction time. In addition, by appropriately controlling the reaction time and dropping rate, the rapid agglomeration of siloxane itself and on the surface of the nanoparticles can be avoided, thereby obtaining a rust inhibitor material with excellent performance.

[0028] Third aspect, the present application provides an application of a rust inhibitor material for precast concrete components, adopting the following technical solutions:

[0029] An application of a rust inhibitor material for precast concrete components, the rust inhibitor material for precast concrete components is added as an admixture during the forming process of precast concrete components, and its dosage range in the added concrete is 8 - 20 kg / m 3 , and the water consumption of the concrete is deducted equally after it is added to the concrete.

[0030] Furthermore, the amount used is determined according to the actual requirements for improving the durability of structural concrete in the construction of precast components and the differences in the actual structural service environment. The recommended dosage in a general corrosion environment is 8 - 16 kg / m 3 , and in a particularly severe corrosion environment, the recommended dosage is 16 - 20 kg / m 3 .

[0031] In summary, the present application has the following beneficial effects:

[0032] (1) The rust inhibitor material for precast concrete components prepared in the present application has strong applicability and has no negative impact on the workability, mechanical properties and production efficiency of concrete such as precast segments and pipe piles. Through the compounding of amino alcohol molecular structure regulation and nanoparticle surface modification, the application performance of the rust inhibitor material in precast concrete is significantly enhanced, realizing the coordinated development of the early mechanical properties and long-term durability of precast segment concrete.

[0033] (2) The rust inhibitor material for precast concrete components prepared in the present application has excellent rust inhibition effect on steel bars. During the high-temperature steam curing process of structural concrete such as precast segments and pipe piles, the volatilization of rust inhibitor components is less, and the long-term rust inhibition performance of steel bars in the structural concrete of precast components is good.

[0034] (3) While improving the rust inhibition performance of steel bars, the rust inhibitor material for precast components prepared in the present application can also improve the compactness of the precast concrete itself, enhance the anti-medium penetration performance of the precast concrete, thereby improving the overall corrosion resistance of the structural concrete.

[0035] (4) The rust inhibitor material for precast concrete components prepared in the present application is particularly suitable for the concrete structure of precast segments in subways and undersea tunnels, and at the same time is particularly suitable for the anti-corrosion and rust inhibition requirements of structural concrete such as pipe piles in severe service environments such as coastal areas and saline soil. It is used for rust protection of steel bars and improvement of the corrosion resistance of concrete itself in concrete structures such as precast segments, pipe piles and precast box girders in severe service environments, and has good application prospects. Moreover, it provides an efficient, low-cost and convenient application technology measure for improving the corrosion resistance of steel bars and the overall corrosion resistance of concrete in the precast concrete system. Specific embodiments

[0036] The following further elaborates on this application in conjunction with embodiments.

[0037] An embodiment of this application first provides a rust inhibitor material for precast concrete components. The rust inhibitor material is composed of raw materials including a steel bar rust inhibitor component with surface-modified nanoparticles and a heterocyclic compound. The weight ratio of the steel bar rust inhibitor component with surface-modified nanoparticles to the heterocyclic compound is 1:(0.001 - 0.05).

[0038] Among them, the steel bar rust inhibitor component with surface-modified nanoparticles is prepared from raw materials including a composite amino alcohol, a siloxane, and a nanomaterial. The weight ratio of the composite amino alcohol, the siloxane, and the nanomaterial is 1:(0.01 - 0.5):(0.1 - 0.5). Among them, the composite amino alcohol is prepared by adding ethylene oxide / propylene oxide to a primary / secondary amine with 2 - 6 carbon atoms, and the number of hydroxyl groups of the composite amino alcohol is 1 - 3. The above-structurally regulated amino alcohol can be obtained by purchasing commercially available amino alcohols or by using conventional epoxy addition reactions. Commercially available amino alcohols include, but are not limited to: ethanolamine, N-methylethanolamine, N-ethylethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, etc.

[0039] The siloxane includes, but is not limited to, trimethoxysilane or triethoxysilane with 1 - 18 alkyl carbon atoms, or amino or glycidyltrimethoxysilane or triethoxysilane with 1 - 6 carbon atoms. The nanomaterial is one or a combination of nano-silica, nano-titanium dioxide, nano-calcium carbonate, nano-C-S-H particles, and nano-silica sol. Further, the particle size of the nanomaterial is 10 - 200 nm, preferably 20 - 60 nm. Both the siloxane and the nanoparticles have the structures disclosed in the specification, and both the siloxane and the nanoparticles are common chemical raw materials and can be purchased through market sales channels.

[0040] The heterocyclic compound is one or a combination of imidazole, thiazole, benzotriazole, and their derivatives. It can be obtained commercially.

[0041] The raw materials of the rust inhibitor material also include functional additives. The functional additives include one or a combination of an air-entraining agent, an antifoaming agent, or a polycarboxylate water reducer; the weight ratio of the steel bar rust inhibitor component with surface-modified nanoparticles, the heterocyclic compound, and the functional additives is 1:(0.001 - 0.05):(0.0001 - 0.05); specifically, the functional additives used in the embodiments of this application include, but are not limited to, an air-entraining agent of model GYQ-1, an antifoaming agent of model PXP-3, and a water reducer of model PCA-I.

[0042] The embodiment of the present application also provides a preparation method of a rust inhibitor material for precast concrete steel bars, including the following steps: Add amino alcohol and nanomaterials into a solvent, stir and disperse evenly, and slowly dropwise add siloxane at a temperature of 10 - 80 °C for 0.5 - 4 h. After the dropping is completed, continue to keep warm and react for 0.5 - 6 h to obtain a rust inhibitor component with modified nanoparticles on the surface. Then add a heterocyclic compound (functional additive), stir for 10 - 30 min, and discharge to obtain the rust inhibitor material for precast concrete steel bars.

[0043] The rust inhibitor material for precast concrete steel bars prepared as above is added as an admixture during the forming process of precast concrete, mainly used to improve the corrosion resistance of precast concrete steel bars.

[0044] The following is explained through specific examples.

[0045] Example 1

[0046] In this example, a rust inhibitor material for precast concrete steel bars was prepared using N-methylethanolamine, nano-silica, dodecyltrimethoxysilane, aminopropyltriethoxysilane, and imidazole as raw materials. The specific preparation process is as follows:

[0047] Add 50 parts of toluene, 40 parts of N-methylethanolamine, and 8 parts of nano-silica into a reaction kettle, stir for 30 min, heat up to 30 °C, and start to dropwise add 1 part of dodecyltrimethoxysilane and 1 part of aminopropyltriethoxysilane. Control the dropping time to 1 h. After adding, continue to keep warm and react for 3 h to prepare a rust inhibitor component with modified nanoparticles on the surface. Then add 0.5 part of imidazole, continue to stir for 30 min, and discharge to obtain a rust inhibitor material S1 for precast concrete steel bars. The particle size of the nanomaterials in this example is 20 nm.

[0048] Example 2

[0049] In this example, a preparation process of a rust inhibitor material for precast concrete steel bars was prepared using N-propylethanolamine, nano-calcium carbonate, n-octyltriethoxysilane, and thiazole as raw materials. The specific preparation process is as follows:

[0050] Add 40 parts of toluene and 20 parts of ethanol, 25 parts of N-propylethanolamine, and 10 parts of nano-silica into a reaction kettle, stir for 30 min, heat up to 40 °C, and start to dropwise add 4.5 parts of n-octyltriethoxysilane. Control the dropping time to 0.5 h. After adding, continue to keep warm and react for 6 h to prepare a rust inhibitor component with modified nanoparticles on the surface. Then add 0.5 part of thiazole, continue to stir for 30 min, and discharge to obtain a rust inhibitor material S2 for precast concrete steel bars. The particle size of the nanomaterials in this example is 40 nm.

[0051] Example 3

[0052] In this example, a preparation process of a rust inhibitor material for precast concrete steel bars is prepared using N, N - dimethylethanolamine, nano - CSH, butyltriethoxysilane, and benzotriazole as raw materials. The specific preparation process is as follows:

[0053] Add 40 parts of toluene, 30 parts of ethanol, 20 parts of N, N - dimethylethanolamine, and 5 parts of nano - CSH into the reaction kettle, stir for 30 min, heat up to 60 °C, start to drop - wise add 5 parts of butyltriethoxysilane, control the dropping time for 2 h, and continue to keep the temperature for reaction for 4 h after adding to prepare the steel bar component with modified nano - particle surface. Then add 0.05 part of benzotriazole and 0.03 part of GYQ - 1, continue to stir for 30 min, and discharge to obtain the rust inhibitor material S3 for precast concrete steel bars. The particle size of the nano - material in this example is 60 nm.

[0054] Example 4

[0055] In this example, a preparation process of a rust inhibitor material for precast concrete steel bars is prepared using N - methyldiethanolamine, nano - silica sol, 3 - aminopropyltriethoxysilane, and isothiazolinone as raw materials. The specific preparation process is as follows:

[0056] Add 40 parts of water, 28 parts of N - methyldiethanolamine, and 20 parts of nano - silica sol into the reaction kettle, stir for 30 min, heat up to 40 °C, start to drop - wise add 2 parts of 3 - aminopropyltriethoxysilane, control the dropping time for 3 h, and continue to keep the temperature for reaction for 5 h after adding to prepare the steel bar component with modified nano - particle surface. Then add 0.2 part of isothiazolinone and 0.01 part of PXP - 3, continue to stir for 30 min, and discharge to obtain the rust inhibitor material S4 for precast concrete steel bars. The particle size of the nano - material in this example is 30 nm.

[0057] Example 5

[0058] In this example, a preparation process of a rust inhibitor material for precast concrete steel bars is prepared using N - ethyldiethanolamine, nano - titanium dioxide, N - 2 - aminoethyl - 3 - aminopropyltriethoxysilane, and methylimidazole as raw materials. The specific preparation process is as follows:

[0059] Add 60 parts of water, 29 parts of N - ethyldiethanolamine, and 8 parts of nano - titanium dioxide into the reaction kettle, stir for 30 min, heat up to 70 °C, start to drop - wise add 3 parts of N - 2 - aminoethyl - 3 - aminopropyltriethoxysilane, control the dropping time for 1 h, and continue to keep the temperature for reaction for 3 h after adding to prepare the steel bar component with modified nano - particle surface. Then add 0.4 part of methylimidazole and 0.5 part of PCA - I, continue to stir for 30 min, and discharge to obtain the rust inhibitor material S5 for precast concrete steel bars. The particle size of the nano - material in this example is 20 nm.

[0060] Example 6

[0061] In this example, a preparation process of a rust inhibitor material for precast concrete steel bars was prepared using N,N-dipropylethanolamine, nano-CSH, glycidoxypropyltriethoxysilane, and 2-amino-5-methylthiazole as raw materials. The specific preparation process is as follows:

[0062] Add 79 parts of ethanol, 15 parts of N,N-dipropylethanolamine, and 5 parts of nano-CSH to the reaction kettle, stir for 30 min, heat up to 70 °C, and start to dropwise add 1 part of glycidoxypropyltriethoxysilane. The dropping time is controlled for 0.5 h. After adding, continue to keep the temperature for reaction for 5 h to prepare a steel bar component with a modified nano-particle surface. Then add 0.4 part of methylimidazole and 0.5 part of PCA-I, continue to stir for 30 min, and discharge to obtain a rust inhibitor material S6 for precast concrete steel bars. The particle size of the nano-material in this example is 30 nm.

[0063] Example 7

[0064] In this example, a preparation process of a rust inhibitor material for precast concrete steel bars was prepared using N,N-dimethylethanolamine, nano-CSH, n-octyltriethoxysilane, thiazole, and PXP-3 defoamer as raw materials. The specific preparation process is as follows:

[0065] Add 50 parts of water, 40 parts of N,N-dimethylethanolamine, and 4 parts of nano-CSH to the reaction kettle, stir for 30 min, heat up to 50 °C, and start to dropwise add 0.4 part of n-octyltriethoxysilane. The dropping time is controlled for 0.5 h. After adding, continue to keep the temperature for reaction for 5 h to prepare a steel bar component with a modified nano-particle surface. Then add 0.04 part of thiazole and 0.004 part of PXP-3, continue to stir for 30 min, and discharge to obtain a rust inhibitor material S7 for precast concrete steel bars. The particle size of the nano-material in this example is 50 nm.

[0066] Example 8

[0067] In this example, a preparation process of a rust inhibitor material for precast concrete steel bars was prepared using ethanolamine, nano-calcium carbonate, 3-aminopropyltriethoxysilane, benzotriazole, and PCA-I water reducer as raw materials. The specific preparation process is as follows:

[0068] Add 50 parts of water, 35 parts of ethanolamine, and 17 parts of nano-calcium carbonate to the reaction kettle, stir for 30 min, heat up to 60 °C, and start to dropwise add 17 parts of 3-aminopropyltriethoxysilane. The dropping time is controlled for 0.5 h. After adding, continue to keep the temperature for reaction for 4 h to prepare a steel bar component with a modified nano-particle surface. Then add 3.4 parts of benzotriazole and 3.4 parts of PCA-I, continue to stir for 30 min, and discharge to obtain a rust inhibitor material S8 for precast concrete steel bars. The particle size of the nano-material in this example is 30 nm.

[0069] Application Examples

[0070] This section lists the application examples of the material. The listed application examples are only the various performances of the material in the segment concrete of this application. Cement-based materials of other precast component systems similar to this application example can also be applied. The following is illustrated through specific application examples and performance tests.

[0071] Application Example: Application in Segment Concrete

[0072] The application of the corrosion inhibitor for steel bars in precast component concrete to segment concrete can improve the early mechanical properties of the segment, and at the same time can enhance the corrosion inhibition performance of steel bars, and also has good effects on chloride ion penetration resistance and sulfate erosion resistance of concrete.

[0073] The mix ratio of the segment concrete of the precast component used is 360 kg / m of cement 3 , 60 kg / m of fly ash 3 , sand ratio of 0.38, water-binder ratio of 0.34, water consumption of 143, and the corrosion inhibitor is used to replace the water consumption equally. Among them, the cement is P·O42.5, the fly ash is Class I fly ash, the sand is river sand, and the gravel is 5 - 20 mm.

[0074] The application of the corrosion inhibitor for steel bars in precast component concrete to the concrete system can effectively improve the anti-medium penetration performance of the concrete, and has good inhibitory effects on chloride ion penetration, sulfate corrosion, and capillary adsorption and enrichment in the dry-wet alternating environment. The samples used are S1 - S8 of this example, and the comparative samples are the commonly used amino alcohol-based corrosion inhibitor samples Forregard 901 and D1 on the market, and the dosage is 12 kg / m 3 .

[0075] The effects of different samples on the mechanical properties, hydrophobicity, and chloride ion diffusion resistance of segment concrete were studied comparatively. Among them, the water absorption rate was detected according to BS1882, the chloride ion diffusion coefficient was detected by the RCM method of the chloride ion diffusion coefficient by electro-migration in GB50082 "Test Methods for Long-Term Durability Performance of Ordinary Concrete", and the anti-sulfate erosion coefficient ratio and corrosion electrical connection ratio were detected according to the test methods in GB / T31296-2014 "Concrete Corrosion Inhibitor". The test results are shown in Table 2.

[0076] Table 2 Durability Performance and Corrosion Inhibition Performance of Concrete

[0077]

[0078] The test results of D1 and S1 - S8 show that the precast component concrete steel bar rust inhibitor material of the present application has a more significant effect on improving the early mechanical properties of segment concrete compared with ordinary amino alcohol steel bar rust inhibitors, and has no adverse effect on the development of the later mechanical properties of concrete. In addition, the steel bar rust inhibitor material of the present application has a certain improvement on the water absorption rate of concrete, and the water absorption rate of concrete decreases significantly. While the same type of steel bar rust inhibitor has almost no improvement on the water absorption rate of concrete, and it has a negative impact on deteriorating the performance of concrete in segment concrete. In addition, the steel bar rust inhibitor material of the present application has a very significant enhancement in the chloride ion penetration resistance, sulfate erosion resistance and steel bar rust inhibition performance of concrete. Especially in the segment concrete system, it still maintains the high - efficiency effect in ordinary concrete and has a better effect than the rust inhibitors commonly used in the market.

[0079] From the performance of D1, the greatest advantage of the present application is that the precast component concrete steel bar rust inhibitor material of the present application has a significant advantage in improving the early mechanical properties, so it meets the requirements of rapid - turnover construction such as precasting and steam curing. In addition, the steel bar rust inhibitor material of the present application shows excellent steel bar rust inhibition performance in the precast component system. It can be seen from the reduction of the corrosion current ratio that less effective rust inhibitor components are lost under high - temperature steam curing conditions for the rust inhibitor material of the present application, and sufficient effective components can better enhance the corrosion resistance of steel bars in the segment concrete system. In addition, while improving and enhancing the steel bar rust inhibition performance in the precast component system, the steel bar rust inhibitor material of the present application also has the characteristics of improving the internal structure and hydrophobicity of the pores of precast component concrete. It can be seen from the reduction of water absorption rate, the improvement of chloride ion penetration resistance and sulfate erosion resistance that the precast component steel bar rust inhibitor material of the present application has very significant multi - functional rust inhibition characteristics and is suitable for the corrosion protection and repair of steel bars in precast structural concrete systems under complex environments.

[0080] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions according to needs, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A corrosion inhibitor material for concrete steel bars of precast components, characterized in that, The rust inhibitor material is composed of raw materials including a steel bar rust inhibitor component with surface modification of nanoparticles and a heterocyclic compound. The weight ratio of the steel bar rust inhibitor component with surface modification of nanoparticles to the heterocyclic compound is 1:(0.001 - 0.05); The steel bar rust inhibitor component with surface modification of nanoparticles is prepared from raw materials including a composite amino alcohol, a siloxane, and a nanomaterial. The weight ratio of the composite amino alcohol, the siloxane, and the nanomaterial is 1:(0.01 - 0.5):(0.1 - 0.5), wherein the composite amino alcohol is prepared by adding ethylene oxide / propylene oxide to a primary / secondary amine with 2 - 6 carbon atoms, and the number of hydroxyl groups of the composite amino alcohol is 1 - 3.

2. The corrosion inhibitor for concrete steel bars of a precast member according to claim 1, characterized in that, The siloxane includes, but is not limited to, trimethoxysiloxane or triethoxysiloxane with an alkyl C atom number of 1 - 18, or amino or glycidyl trimethoxysiloxane or triethoxysiloxane with an alkyl C atom number of 1 - 6.

3. The corrosion inhibitor for concrete steel bars of a precast component according to claim 1, characterized in that, The nanomaterial is one or a combination of more of nano - silica, nano - titanium dioxide, nano - calcium carbonate, nano - C - S - H particles, and nano - silica sol.

4. A precast concrete component steel bar rust inhibitor material according to claim 3, characterized in that, The particle size of the nanomaterial is 10 - 200 nm.

5. A precast concrete component steel corrosion inhibitor material according to claim 4, characterized in that, The particle size of the nanomaterial is 20 - 60 nm.

6. The corrosion inhibitor for concrete steel bars of a precast member according to claim 1, wherein The heterocyclic compound is one or a combination of more of imidazole, thiazole, benzotriazole, and their derivatives.

7. A precast concrete component steel bar rust inhibitor material according to claim 1, characterized in that, The raw materials of the rust inhibitor material further include a functional additive. The weight ratio of the steel bar rust inhibitor component with surface modification of nanoparticles, the heterocyclic compound, and the functional additive is 1:(0.001 - 0.05):(0.0001 - 0.05).

8. A precast concrete component steel bar rust inhibitor material according to claim 7, characterized in that, The functional additive includes one or a combination of more of an air - entraining agent, an antifoaming agent, or a polycarboxylate water - reducing agent.

9. A preparation method of a precast member concrete steel bar rust inhibitor material according to any one of claims 1 to 8, characterized in that, It includes the following steps: Add the amino alcohol and the nanomaterial into a solvent, stir and disperse evenly. At a temperature of 10 - 80 °C, slowly drop - add the siloxane. The dropping time is 0.5 - 4 h. After the dropping is completed, continue to keep warm and react for 0.5 - 6 h to obtain the steel bar rust inhibitor component with surface modification of nanoparticles. Then add the heterocyclic compound and stir for 10 - 30 min, and discharge to obtain the precast concrete steel bar rust inhibitor material.

10. Use of a precast member concrete steel bar rust inhibitor material according to any one of claims 1 to 8, characterized in that, The rust inhibitor material for precast concrete components is added as an admixture during the forming process of precast concrete components, and its dosage range in the added concrete is 8-20 kg / m 3 relative to the volume admixture of the concrete, and the water consumption of the concrete is deducted equally after it is added to the concrete.

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