Enhanced concrete corrosion inhibitor and method of making same

Abstract

The application relates to the technical field of building materials, and particularly discloses a reinforced concrete corrosion-resistant rust inhibitor and a preparation method thereof. The product comprises active silicon dioxide micro powder, sulphoaluminate cement clinker, calcium nitrate, sodium molybdate, amino alcohol organic rust inhibitor, hydroxypropyl methyl cellulose, hydroxyl-terminated polydimethylsiloxane and superfine limestone powder; and the preparation method comprises the following steps: first, pre-treating and grinding part of raw materials, then dispersing active components, subsequently, segmentally compounding materials, and then performing liquid-phase surface modification, and finally mixing the product with a thickening water-retaining agent after homogenization and maturation. The product can be used in concrete of infrastructure such as bridges and tunnels, has the advantages of synergistically optimizing the compactness of the concrete, inhibiting the rusting of steel bars, guaranteeing the mixing water-retaining property and enhancing the impermeability, and improving the comprehensive corrosion-resistant rust-inhibiting performance; in addition, the preparation method has the advantages of orderly step connection, uniform distribution of components, stable product function, and easy industrial production.

Description

Technical Field

[0001] This application relates to the field of building materials technology, and more specifically, it relates to an enhanced concrete corrosion inhibitor and rust inhibitor and its preparation method. Background Technology

[0002] In the field of construction engineering, concrete is widely used as a core structural material in infrastructure such as bridges, tunnels, and marine engineering. These facilities are exposed to complex environments such as rainwater, chloride ions, and humidity changes for extended periods, making them prone to problems such as water seepage through internal pores and the intrusion of harmful ions. This can lead to steel corrosion, concrete cracking and spalling, ultimately affecting the structural load-bearing capacity and service life. Therefore, specialized concrete anti-corrosion and rust inhibitors are needed to improve the concrete's resistance to environmental erosion and extend the service life of infrastructure by optimizing the internal structure of the concrete and inhibiting the electrochemical corrosion of the steel reinforcement.

[0003] Currently, many concrete corrosion-resistant and rust-inhibiting products on the market suffer from a lack of functionality: some products focus solely on inhibiting steel corrosion through a single rust-inhibiting component, failing to effectively improve the concrete's density and impermeability, allowing harmful ions to still penetrate through pores; others focus on improving concrete impermeability but lack long-term inhibition of steel corrosion; still others fail to consider water retention during mixing, easily affecting concrete molding quality due to moisture loss. These products cannot simultaneously achieve the comprehensive effects of optimizing the internal structure of concrete, inhibiting steel corrosion, ensuring mixing water retention, and enhancing impermeability, making it difficult to meet the comprehensive requirements of infrastructure for long-term corrosion resistance and rust inhibition performance of concrete. Summary of the Invention

[0004] To address the problem that existing concrete anti-corrosion and rust-inhibiting products lack functional synergy, making it difficult to simultaneously achieve structural optimization, steel reinforcement rust prevention, mixing water retention, and impermeability, and thus fail to meet the long-term performance requirements of complex infrastructure environments, this application provides an enhanced concrete anti-corrosion and rust-inhibiting agent and its preparation method.

[0005] In a first aspect, this application provides a reinforced concrete corrosion inhibitor, employing the following technical solution:

[0006] A reinforced concrete corrosion inhibitor is made from the following raw materials in parts by weight: 25-45 parts of active silica micro powder; 15-30 parts of sulfoaluminate cement clinker; 5-15 parts of calcium nitrate; 3-10 parts of sodium molybdate; 4-12 parts of amino alcohol organic corrosion inhibitor; 0.3-1.5 parts of cellulose ether thickener and water-retaining agent; 0.5-2.0 parts of modified silicone oil water-repellent agent; and 10-30 parts of ultrafine limestone powder.

[0007] By employing the above technical solutions, the high pozzolanic activity of activated silica micropowder reacts with cement hydration products to generate more hydrated calcium silicate gel, thereby filling the internal pores of concrete and optimizing structural density. The rapid hardening characteristics of sulfoaluminate cement clinker facilitate rapid hydration to generate dense hydration products, accelerating the early structural formation of concrete and improving early impermeability. Calcium nitrate and sodium molybdate release functional ions to form a protective film on the steel reinforcement surface, inhibiting electrochemical corrosion and reducing the risk of steel corrosion. Finally, amino alcohol-based organic corrosion inhibitors adsorb onto the steel reinforcement surface to form a dense adsorption layer, blocking corrosion. The contact between the corrosive medium and the reinforcing steel helps to enhance the long-term rust-inhibiting effect; the cellulose ether thickener improves the water retention of the concrete mix and reduces water loss, preventing the concrete from becoming structurally loose due to water loss, thus ensuring the quality of concrete molding; the modified silicone oil water-repellent agent forms a water-repellent film inside the concrete, blocking the intrusion of water and harmful ions, thereby improving the long-term impermeability and corrosion resistance of the concrete; the fine particles of ultrafine limestone powder fill the tiny pores formed by cement hydration, further refining the internal pore structure of the concrete, thus helping to improve the overall density and reduce the penetration channels of corrosive media.

[0008] Preferably, the specific surface area of ​​the active silica micropowder is 18000-25000 m². 2 / kg, and the silica content is not less than 92%.

[0009] By adopting the above technical solution, the specific surface area of ​​the active silica micropowder is limited, giving it a larger powder contact area. This allows it to fully contact the calcium hydroxide produced during cement hydration, promoting a more efficient pozzolanic reaction. Simultaneously, limiting the silica content to no less than 92% reduces the presence of impurities, preventing them from consuming hydration products or hindering gel formation. This ensures the purity and quantity of the calcium silicate hydrate gel generated, resulting in more complete filling of the concrete's internal pores and more effectively optimizing the concrete's dense structure. This lays a stable structural foundation for subsequent improvements in corrosion resistance and rust prevention.

[0010] Preferably, the amino alcohol organic rust inhibitor is at least one of diethanolamine, triethanolamine and aminobutanol.

[0011] By adopting the above technical solution, and utilizing the shared amino and hydroxyl group characteristics of these three substances, diethanolamine, with its moderate amino activity, can stably adsorb onto the surface of the reinforcing steel, forming an initial rust-inhibiting protective film. Triethanolamine, in addition to its adsorption function, can also slightly promote cement hydration, thus helping to optimize the concrete matrix structure and reduce the penetration channels of corrosive media. The carbon chain structure of aminobutanol enhances the density of the adsorption film, improving its resistance to corrosive media intrusion. Simultaneously, when these three substances are combined with inorganic rust inhibitors such as calcium nitrate and sodium molybdate in the formulation, a synergistic effect of "organic adsorption film blocking corrosion contact + inorganic ions inhibiting electrochemical corrosion" is formed, strengthening the rust-inhibiting effect. This results in a more stable and long-lasting protection of the reinforcing steel from corrosion, avoiding problems such as insufficient rust-inhibiting function or poor compatibility with the system caused by using other amino alcohols, which may have excessively high activity leading to unstable adsorption or poor compatibility affecting concrete performance.

[0012] Preferably, the cellulose ether thickening and water-retaining agent is hydroxypropyl methylcellulose with a viscosity of 40,000-100,000 mPa·s.

[0013] By adopting the above technical solution and limiting the cellulose ether thickener and water-retaining agent to hydroxypropyl methylcellulose, its good solubility and dispersibility in concrete mixing water can be utilized, thus avoiding the compatibility problems of other cellulose ethers. This allows it to be evenly distributed in the mixing system and stably perform its thickening and water-retaining functions. At the same time, its viscosity is limited to 40,000-100,000 mPa·s. Too low a viscosity will result in insufficient water retention capacity, easy water loss during concrete mixing, and loose internal structure. Too high a viscosity will reduce the fluidity of the mixture and affect construction and pouring. This viscosity range can balance water retention and workability, continuously locking in the mixing water and reducing porosity caused by water evaporation, while ensuring good fluidity of the concrete mixture. This achieves the effect of ensuring the compactness of the concrete and avoiding the impact of water loss or construction obstruction on the corrosion-resistant base performance.

[0014] Preferably, the modified silicone oil hydrophobic agent is hydroxyl-terminated polydimethylsiloxane.

[0015] By adopting the above technical solution, and specifying the modified silicone oil water-repellent agent as hydroxyl-terminated polydimethylsiloxane, the hydroxyl group in its molecular structure can chemically bond with the hydroxyl groups on the surface of hydrated calcium silicate gel generated during cement hydration. This effectively anchors the hydrophobic polydimethylsiloxane backbone firmly into the internal structure of concrete, avoiding the problems of ordinary unterminated modified silicone oils relying solely on physical adhesion and easily detaching, and the water-repellent effect diminishing over time. Simultaneously, the polydimethylsiloxane backbone possesses excellent hydrophobicity, forming a continuous and dense hydrophobic film within the concrete, preventing external moisture, chloride ions, and other harmful corrosive media from penetrating into the concrete through pores. Furthermore, this substance exhibits good compatibility with other components in the formulation, preventing the formation of bubbles or structural defects due to incompatibility between components, thus ensuring the overall structural density of the concrete remains unaffected. This achieves a long-term, stable improvement in the concrete's impermeability and corrosion resistance, providing a reliable environmental guarantee for steel reinforcement corrosion prevention.

[0016] Preferably, the calcium carbonate content in the ultrafine limestone powder is not less than 95%.

[0017] By adopting the above technical solution, the particle size distribution of the ultrafine limestone powder is Dv50 between 5.0 and 8.0 μm, and Dv90 not greater than 20.0 μm. This ensures that the powder particles are of moderate size and concentrated distribution. Within this Dv50 range, the powder can accurately fill the micron-sized pores formed during cement hydration, preventing agglomeration due to excessively fine particles or inability to enter the micro-spaces due to excessively coarse particles. A Dv90 not greater than 20.0 μm reduces the presence of large particles, preventing the formation of interconnected gaps between large particles that become channels for corrosive media penetration, thus refining the particle size distribution and improving filling accuracy. Simultaneously, combined with the high purity characteristic of calcium carbonate content not less than 95%, impurities are prevented from interfering with the filling effect. This allows the ultrafine limestone powder to form a nano- and micron-level synergistic filling system with active silica powder, more comprehensively blocking pores of different sizes within the concrete. This further reduces porosity and the penetration path of corrosive media, providing a more stable physical structure support for the corrosion resistance of concrete.

[0018] Secondly, this application provides a method for preparing an enhanced concrete corrosion inhibitor, employing the following technical solution:

[0019] A method for preparing a reinforced concrete corrosion-resistant and rust-inhibiting agent includes the following steps:

[0020] S1. Pretreatment and coarse grinding: Add the corresponding weight parts of sulfoaluminate cement clinker and ultrafine limestone powder into the grinding equipment and grind them together for 25-40 minutes at a speed of 250-350 r / min to obtain mixed base material A.

[0021] S2. Dispersion of active components: Add the corresponding weight parts of active silica micro powder, calcium nitrate and sodium molybdate into a high-efficiency vortex disperser and dry disperse at a speed of 1200-1800 r / min for 15-25 minutes until the coefficient of variation of the mixing uniformity is less than 5% to obtain mixed active component B.

[0022] S3. Segmented fine compounding: The mixed base material A is added to the dispersion equipment containing the mixed active component B in three parts. After each addition, the mixture is stirred at a speed of 800-1000 r / min for 10-15 minutes to finally form the composite powder C.

[0023] S4. Liquid phase surface modification: The corresponding weight parts of amino alcohol organic rust inhibitor and modified silicone oil water repellent are premixed and evenly sprayed onto the surface of composite powder C in a rolling state through an atomizing nozzle. During the spraying process, the container temperature is maintained at 45-55℃.

[0024] S5. Homogenization and maturation: The material after liquid phase surface modification is transferred to the homogenization chamber and allowed to stand and mature at a constant temperature of 50-60℃ for 24-36 hours.

[0025] S6. Final mixing: Transfer the matured material and the corresponding weight of cellulose ether thickener and water-retaining agent into the mixing equipment, mix at a low speed of 50-60 r / min for 45-60 minutes, until the uniformity is greater than 98%, and the final product is obtained.

[0026] By adopting the above technical solutions, the pretreatment and coarse grinding in S1 allows sulfoaluminate cement clinker and ultrafine limestone powder to be co-ground at a specific speed, adjusting their fineness to a suitable range and achieving initial mixing, thus providing a uniform base material for subsequent composite processes. The high-speed dry dispersion in S2 fully disperses the active silica micropowder, calcium nitrate, and sodium molybdate, breaking up particle agglomeration and ensuring uniform distribution of active components, thereby preventing component aggregation from affecting their functionality. The segmented fine composite in S3 adds the mixed base material A in three stages with stirring, reducing stratification caused by density differences and promoting the gradual integration of the base material and active components, thus improving the overall performance. The process enhances the overall uniformity of the mixture. Through S4, liquid-phase surface modification atomizes and sprays organic rust inhibitors and water-repellents onto the surface of the rolling composite powder while controlling the temperature. This ensures the liquid-phase modifier uniformly coats the powder and strengthens interfacial bonding, thereby guaranteeing comprehensive coverage of the modified components. S5, homogenization and curing, involves static treatment of the modified material under constant temperature conditions, promoting stable bonding between the modifier and powder particles, thus enhancing interfacial stability. S6, final mixing, involves mixing the cured material with cellulose ether at low speed to a high standard of uniformity. This avoids damaging the existing structure and ensures uniform dispersion of the thickening and water-retaining agent, ultimately guaranteeing consistent distribution and synergistic function of all components in the finished product.

[0027] Preferably, in step S1, the grinding media used in the grinding equipment is zirconia balls, with a particle size ratio of 40% balls with a diameter of 3 mm and 60% balls with a diameter of 5 mm.

[0028] By adopting the above technical solution, in step S1, zirconia balls are selected as the grinding media. Utilizing their high hardness and low wear characteristics, this prevents media debris from mixing into the sulfoaluminate cement clinker and ultrafine limestone powder during the grinding process. This prevents impurities from interfering with the cement hydration reaction or affecting the subsequent function of the rust inhibitor, thus ensuring the purity of the raw materials. Simultaneously, a particle size ratio of 40% 3mm balls and 60% 5mm balls is used. The smaller-diameter balls fill the gaps between the larger-diameter balls, increasing the contact area between the material and the media during grinding. The larger-diameter balls provide stronger impact grinding force. Together, they improve grinding efficiency and ensure uniform material fineness. This avoids the problems caused by improper selection of grinding media, such as the easy wear and slag formation of ordinary alumina balls or uneven grinding of single-diameter balls, which can lead to raw material contamination or localized over-coarsening, resulting in inaccurate filling of concrete pores. Conversely, overly fine grinding media can easily agglomerate, forming new defects. This achieves the goal of ensuring that the mixed base material A has the appropriate fineness and purity, laying a stable foundation for subsequent full compounding with active components and the synergistic effect of filling and cementing.

[0029] Preferably, in step S4, the working pressure of the atomizing nozzle is 0.3-0.6 MPa, and the atomized droplet particle size is no greater than 50 μm.

[0030] By adopting the above technical solution, and limiting the working pressure of the atomizing nozzle in step S4 to 0.3-0.6 MPa, it can avoid insufficient atomization of droplets due to excessively low pressure, which can lead to large droplets that easily cause local wetting and agglomeration of the composite powder C, thus damaging the powder dispersibility. It can also prevent excessively high pressure from causing droplets to become too fine and easily fly away with the airflow, or from excessive local aggregation of powder leading to uneven distribution of the modifier. This ensures that the amino alcohol-based organic rust inhibitor and the modified silicone oil water-repellent form a stable atomization state; simultaneously, it limits the atomized droplets. With a particle size of no more than 50μm, the fine droplets have a larger contact area, which can uniformly cover the surface of the composite powder C in the rolling state. This avoids large droplets only adhering to local areas of the powder and forming blind spots, ensuring that each powder particle is fully coated by the modifier. The two work together to make the liquid phase modifier and the powder interface more uniform and tight, avoiding the problem of insufficient local rust inhibition or weak impermeability due to uneven distribution of the modifier in subsequent concrete applications. This achieves a stable effect of synergistic rust inhibition and water repellency.

[0031] Preferably, in step S5, the relative humidity of the homogenization chamber is controlled below 40%.

[0032] By adopting the above technical solution, and by controlling the relative humidity of the homogenization chamber in step S5 to below 40%, it is possible to effectively prevent the adsorption of moisture in the air by the composite powder C during the homogenization and curing process. If the humidity is too high, the amino alcohol organic rust inhibitor and modified silicone oil water-repellent on the powder surface may agglomerate and clump due to moisture absorption, or react unexpectedly with moisture, destroying the already formed surface coating structure. This plays a role in maintaining the dispersion state of the powder and protecting the stability of the interface between the modifier and the powder. At the same time, the low humidity environment provides sufficient time for the modifier and powder particles to complete a stable bond, avoiding moisture interference with the interface between the two, ensuring that each powder particle can maintain a uniform modified state. This ensures that the material can be evenly dispersed during the final mixing in step S6, avoiding uneven distribution of the rust inhibitor in the concrete due to agglomeration, resulting in localized corrosion resistance or weak rust inhibition function, thus laying the foundation for the stable comprehensive performance of the final product.

[0033] In summary, this application has the following beneficial effects:

[0034] 1. Because this application uses a raw material system composed of active silica micro powder, sulfoaluminate cement clinker, calcium nitrate, sodium molybdate, amino alcohol organic rust inhibitor, cellulose ether thickener and water-retaining agent, modified silicone oil water-repellent agent and ultrafine limestone powder, the active silica micro powder and sulfoaluminate cement clinker can synergistically optimize the internal structure of concrete and improve its density. The organic and inorganic rust inhibitors work together to inhibit steel corrosion. The thickener and water-retaining agent ensures the water retention of the mixture and the modified silicone oil water-repellent agent enhances the impermeability, thus achieving the effect of improving the comprehensive performance of concrete in terms of corrosion resistance and rust prevention.

[0035] 2. In this application, a specific surface area of ​​18,000-25,000 m² is preferred. 2 The optimized raw material parameters, including activated silica micro powder with a silica content of not less than 92% per kg, specific types of amino alcohol organic rust inhibitors, hydroxypropyl methylcellulose with a viscosity of 40,000-100,000 mPa·s, hydroxyl-terminated polydimethylsiloxane, and ultrafine limestone powder with a calcium carbonate content of not less than 95%, ensure the dispersibility, functional compatibility, and stability of each component, avoiding functional failure due to insufficient raw material characteristics, and achieving the effect of ensuring the stable performance of the rust inhibitor.

[0036] 3. The method of this application controls the fineness of raw materials through pretreatment and coarse grinding, ensures uniformity by dispersing active components, avoids agglomeration through segmented fine compounding, achieves uniform coating of liquid phase modifier through atomizing nozzle, promotes reaction by constant temperature and humidity homogenization and maturation, and ensures overall uniformity by low-speed final mixing. The orderly and coordinated steps solve the problems of uneven mixing of raw materials and insufficient modification, thus achieving the effect of improving the uniformity and stability of rust inhibitor products. Attached Figure Description

[0037] Figure 1 This is a flowchart of a method for preparing an enhanced concrete corrosion inhibitor provided in this application. Detailed Implementation

[0038] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0039] Technical concept:

[0040] Existing technologies related to concrete corrosion resistance and rust inhibition generally suffer from insufficient functional synergy, making it difficult to simultaneously meet the comprehensive needs of optimizing concrete density, inhibiting steel corrosion, ensuring water retention during mixing, and enhancing impermeability. The core reasons for this are: most technologies focus only on single-function design, or use only one type of rust inhibitor, such as only inorganic or only organic rust inhibitors, lacking the synergistic effect of different rust-inhibiting components; or they neglect the combination of highly active filler materials and cementitious materials, failing to effectively optimize the internal pore structure of concrete; or they fail to rationally combine water-retaining and water-repellent components, resulting in poor connection between water retention during concrete mixing and impermeability after hardening, ultimately leading to fragmented product functions and an inability to cope with the multi-dimensional corrosion resistance needs of concrete structures in complex environments.

[0041] This technical solution addresses the aforementioned problems by constructing a multi-component synergistic raw material system and a functionally compatible design approach: Active silica micropowder and sulfoaluminate cement clinker are selected as core structural optimization components, utilizing the synergistic effect of pozzolanic activity and rapid hardening properties to enhance concrete density; calcium nitrate, sodium molybdate, and amino alcohol organic rust inhibitors are compounded, strengthening the steel corrosion inhibition effect through the synergistic effect of ion exchange and surface adsorption; cellulose ether thickeners and water-retaining agents are added to ensure water retention during mixing, and modified silicone oil water-repellent agents are used to enhance the impermeability of hardened concrete; simultaneously, ultrafine limestone powder is introduced to refine the pore structure. The components are functionally complementary and synergistic in their effects, ultimately forming a solution with comprehensive performance encompassing structural optimization, rust inhibition, water retention, and impermeability.

[0042] Preparation Example 1

[0043] The preparation method of activated silica micro powder is as follows:

[0044] 100 parts of industrial-grade silica fume with an initial silica content of 88%-90% were used as raw materials. Three times the mass of the silica fume was added to a 10% hydrochloric acid solution, and the mixture was placed in a reactor equipped with a stirrer. The mixture was stirred at 200 r / min for 2 hours under a constant temperature water bath at 60℃. Metal impurities in the silica fume were removed by acid washing. After stirring, a plate and frame filter press was used for solid-liquid separation. The filter cake was collected and repeatedly washed with deionized water until the pH of the filtrate stabilized at 6.5. The washed filter cake was then placed in a 110℃ forced-air drying oven and dried for 8 hours to obtain purified silica fume.

[0045] The purified silica fume was then fed into an air jet mill, with the mill pressure adjusted to 0.8 MPa and the classifier speed to 12000 r / min. The mill was then started for ultrafine grinding, during which the particle size distribution was monitored in real time using an online laser particle size analyzer. Grinding was stopped once the particle size met the requirements for specific surface area calculation. Finally, the ground powder was transferred to a high-temperature activation furnace and activated at 800℃ for 2 hours to enhance its pozzolanic activity. After cooling to room temperature, samples were taken for testing, ultimately yielding a specific surface area of ​​18000-25000 m². 2 Active silica micro powder with a silica content of not less than 92% and a density of / kg.

[0046] The main raw materials and reagents used in the following preparation examples, embodiments, and comparative examples are as follows, and their sources and specifications are as follows. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products:

[0047] 1. Diethanolamine was purchased from Nanjing Kerunjiang Chemical Co., Ltd., CAS: 111-42-2;

[0048] 2. Triethanolamine was purchased from Nanjing Kerunjiang Chemical Co., Ltd., CAS: 102-71-6;

[0049] 3. Aminobutanol was purchased from Hubei Yongkuo Technology Co., Ltd., CAS: 61477-40-5;

[0050] 4. Hydroxypropyl methylcellulose was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number H108826;

[0051] 5. Hydroxyl-terminated polydimethylsiloxane was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd., product number PB98893.

[0052] Example 1

[0053] This application provides an enhanced concrete corrosion inhibitor, made from the following raw materials in parts by weight: 35 parts of active silica micro powder; 22 parts of sulfoaluminate cement clinker; 10 parts of calcium nitrate; 6 parts of sodium molybdate; 8 parts of amino alcohol organic corrosion inhibitor; 1 part of cellulose ether thickening and water-retaining agent; 1.5 parts of modified silicone oil water-repellent agent; and 20 parts of ultrafine limestone powder.

[0054] The specific surface area of ​​the active silica micropowder is 21500 m². 2 / kg, and the silica content is not less than 92%; the amino alcohol organic rust inhibitor is diethanolamine and triethanolamine; the cellulose ether thickener and water retainer is hydroxypropyl methylcellulose with a viscosity of 70000 mPa·s; the modified silicone oil water repellent is hydroxyl-terminated polydimethylsiloxane; the calcium carbonate content in the ultrafine limestone powder is not less than 95%.

[0055] The preparation method of the above-mentioned reinforced concrete corrosion inhibitor includes the following steps:

[0056] S1. Pretreatment and coarse grinding: 22 parts by weight of sulfoaluminate cement clinker and 20 parts by weight of ultrafine limestone powder are put into a grinding equipment and ground together for 32 minutes at a speed of 300 r / min to obtain mixed base material A.

[0057] The grinding media used in the grinding equipment are zirconia balls, with a particle size ratio of 40% balls with a diameter of 3mm and 60% balls with a diameter of 5mm.

[0058] S2. Dispersion of active components: 35 parts by weight of active silica micro powder, 10 parts by weight of calcium nitrate and 6 parts by weight of sodium molybdate are put into a high-efficiency vortex disperser and dry dispersed at a speed of 1500 r / min for 20 minutes until the coefficient of variation of the mixing uniformity is less than 5%, thus obtaining mixed active component B.

[0059] S3. Segmented fine compounding: Mixed base material A is added to a dispersion device containing mixed active component B in three parts. After each addition, the mixture is stirred at 900 r / min for 12 minutes to finally form composite powder C.

[0060] S4. Liquid phase surface modification: 8 parts by weight of amino alcohol organic rust inhibitor and 1.5 parts by weight of modified silicone oil water repellent are premixed and evenly sprayed onto the surface of composite powder C in a rolling state through an atomizing nozzle. During the spraying process, the container temperature is maintained at 50℃.

[0061] The working pressure of the atomizing nozzle is 0.45 MPa, and the atomized droplet size is no greater than 50 μm.

[0062] S5. Homogenization and maturation: The material after liquid phase surface modification is transferred to the homogenization chamber and allowed to stand and mature at a constant temperature of 55℃ for 30 hours.

[0063] The relative humidity in the homogenization chamber is controlled below 40%.

[0064] S6. Final mixing: Transfer the matured material together with 0.9 parts by weight of cellulose ether thickener and water-retaining agent into the mixing equipment, mix at a low speed of 55 r / min for 52.5 minutes, and mix until the uniformity is greater than 98% to obtain the final product.

[0065] Example 2

[0066] This application provides an enhanced concrete corrosion inhibitor, made from the following raw materials in parts by weight:

[0067] 25 parts of active silica micro powder; 15 parts of sulfoaluminate cement clinker; 5 parts of calcium nitrate; 3 parts of sodium molybdate; 4 parts of amino alcohol organic rust inhibitor; 0.3 parts of cellulose ether thickener and water-retaining agent; 0.5 parts of modified silicone oil water-repellent agent; 10 parts of ultrafine limestone powder.

[0068] The specific surface area of ​​the activated silica micropowder is 18000 m². 2 / kg, and the silica content is not less than 92%; the amino alcohol organic rust inhibitor is selected from triethanolamine and aminobutanol; the cellulose ether thickener and water retainer is hydroxypropyl methylcellulose with a viscosity of 40000 mPa·s; the modified silicone oil water repellent is hydroxyl-terminated polydimethylsiloxane; the calcium carbonate content in the ultrafine limestone powder is not less than 95%.

[0069] The preparation method of the above-mentioned reinforced concrete corrosion inhibitor includes the following steps:

[0070] S1. Pretreatment and coarse grinding: 15 parts by weight of sulfoaluminate cement clinker and 10 parts by weight of ultrafine limestone powder are put into a grinding equipment and ground together for 25 minutes at a speed of 250 r / min to obtain mixed base material A.

[0071] The grinding media used in the grinding equipment are zirconia balls, with a particle size ratio of 40% balls with a diameter of 3mm and 60% balls with a diameter of 5mm.

[0072] S2. Dispersion of active components: 25 parts by weight of active silica micro powder, 5 parts by weight of calcium nitrate and 3 parts by weight of sodium molybdate are put into a high-efficiency vortex disperser and dry dispersed at a speed of 1200 r / min for 15 minutes until the coefficient of variation of the mixing uniformity is less than 5%, thus obtaining mixed active component B.

[0073] S3. Segmented fine compounding: The mixed base material A is added to the dispersion device containing the mixed active component B in three parts. After each addition, the mixture is stirred at 800 r / min for 10 minutes to finally form the composite powder C.

[0074] S4. Liquid phase surface modification: 4 parts by weight of amino alcohol organic rust inhibitor and 0.5 parts by weight of modified silicone oil water repellent are premixed and evenly sprayed onto the surface of composite powder C in a rolling state through an atomizing nozzle. During the spraying process, the container temperature is maintained at 45℃.

[0075] The working pressure of the atomizing nozzle is 0.3 MPa, and the atomized droplet size is no greater than 50 μm.

[0076] S5. Homogenization and maturation: The material after liquid phase surface modification is transferred to the homogenization chamber and allowed to stand and mature at a constant temperature of 50℃ for 24 hours.

[0077] The relative humidity in the homogenization chamber is controlled below 40%.

[0078] S6. Final mixing: Transfer the matured material together with 0.3 parts by weight of cellulose ether thickener and water-retaining agent into the mixing equipment, mix at a low speed of 50 r / min for 45 minutes, and mix until the uniformity is greater than 98% to obtain the final product.

[0079] Example 3

[0080] This application provides an enhanced concrete corrosion inhibitor, made from the following raw materials in parts by weight:

[0081] 45 parts of active silica micro powder; 30 parts of sulfoaluminate cement clinker; 15 parts of calcium nitrate; 10 parts of sodium molybdate; 12 parts of amino alcohol organic rust inhibitor; 1.5 parts of cellulose ether thickener and water-retaining agent; 2.0 parts of modified silicone oil water-repellent agent; 30 parts of ultrafine limestone powder.

[0082] The specific surface area of ​​the activated silica micropowder is 25,000 m². 2 / kg, and the silica content is not less than 92%; the amino alcohol organic rust inhibitor is at least one of diethanolamine, triethanolamine and aminobutanol; the cellulose ether thickener and water-retaining agent is hydroxypropyl methylcellulose with a viscosity of 100,000 mPa·s; the modified silicone oil water-repellent agent is hydroxyl-terminated polydimethylsiloxane; the calcium carbonate content in the ultrafine limestone powder is not less than 95%.

[0083] The preparation method of the above-mentioned reinforced concrete corrosion inhibitor includes the following steps:

[0084] S1. Pretreatment and coarse grinding: 30 parts by weight of sulfoaluminate cement clinker and 30 parts by weight of ultrafine limestone powder are put into a grinding equipment and ground together for 40 minutes at a speed of 350 r / min to obtain mixed base material A.

[0085] The grinding media used in the grinding equipment are zirconia balls, with a particle size ratio of 40% balls with a diameter of 3mm and 60% balls with a diameter of 5mm.

[0086] S2. Dispersion of active components: 45 parts by weight of active silica micro powder, 15 parts by weight of calcium nitrate and 10 parts by weight of sodium molybdate are put into a high-efficiency vortex disperser and dry dispersed at a speed of 1800 r / min for 25 minutes until the coefficient of variation of the mixing uniformity is less than 5%, thus obtaining mixed active component B.

[0087] S3. Segmented fine compounding: The mixed base material A is added to the dispersion device containing the mixed active component B in three parts. After each addition, the mixture is stirred at 1000r / min for 15 minutes to finally form the composite powder C.

[0088] S4. Liquid phase surface modification: 12 parts by weight of amino alcohol organic rust inhibitor and 2.0 parts by weight of modified silicone oil water repellent are premixed and evenly sprayed onto the surface of composite powder C in a rolling state through an atomizing nozzle. During the spraying process, the container temperature is maintained at 55℃.

[0089] The working pressure of the atomizing nozzle is 0.6 MPa, and the atomized droplet size is no greater than 50 μm.

[0090] S5. Homogenization and maturation: The material after liquid phase surface modification is transferred to the homogenization chamber and allowed to stand and mature at a constant temperature of 60℃ for 36 hours.

[0091] The relative humidity in the homogenization chamber is controlled below 40%.

[0092] S6. Final mixing: Transfer the matured material together with 1.5 parts by weight of cellulose ether thickener and water-retaining agent into the mixing equipment, mix at a low speed of 60 r / min for 60 minutes, and mix until the uniformity is greater than 98% to obtain the final product.

[0093] Comparative Example 1

[0094] The only difference between this comparative example and Example 1 is that the active silica micropowder is completely removed and its weight is replaced by an equal amount of ultrafine limestone powder. The remaining components, dosages, and preparation processes are exactly the same as in Example 1.

[0095] Comparative Example 2

[0096] The only difference between this comparative example and Example 1 is that sodium molybdate and calcium nitrate are completely removed; the remaining components, dosages, and preparation processes are exactly the same as in Example 1.

[0097] Comparative Example 3

[0098] The only difference between this comparative example and Example 1 is that all the sulfoaluminate cement clinker is replaced with an equal amount of ordinary silicate cement clinker, while the remaining components, dosages, and preparation processes are exactly the same as in Example 1.

[0099] Comparative Example 4

[0100] The ultrafine limestone powder with a calcium carbonate content of ≥95% was replaced with an equal amount of ordinary quartz sand powder with a silica content of ≥95%, and the remaining components, dosages, and preparation processes were exactly the same as in Example 1.

[0101] Comparative Example 5

[0102] The only difference between this comparative example and Example 1 is that steps S1, S2, and S3 are omitted. Instead, all powdered raw materials, including active silica micro powder, sulfoaluminate cement clinker, ultrafine limestone powder, calcium nitrate, and sodium molybdate, are added to the dispersion equipment at once and mixed at 1500 r / min for 20 minutes before proceeding to steps S4 and subsequent steps. The composition, dosage, and preparation process after step S4 are exactly the same as in Example 1.

[0103] Comparative Example 6

[0104] The only difference between this comparative example and Example 1 is that the uniform spraying operation of the atomizing nozzle in step S4 is cancelled, and instead, the amino alcohol organic rust inhibitor and the modified silicone oil water repellent are directly added to the mixing equipment along with the cured material for mixing.

[0105] I. Concrete impermeability test

[0106] The experiment was conducted in accordance with GB / T50082-2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete".

[0107] Multiple sets of standard-sized concrete test blocks were prepared. The baseline group consisted of ordinary concrete without any added rust inhibitor. The experimental and control groups used the enhanced concrete corrosion inhibitors from Examples 1-3 and the rust inhibitors from Comparative Examples 1-6, respectively, added to the concrete at 3% of the cement content. The standard concrete mix proportion was 300 kg / m³ of 42.5 grade ordinary Portland cement. 3 650kg / m³ of river sand 3 1200 kg / m³ of crushed stone 3 The water-cement ratio was 0.45. Three permeability test specimens (Φ175mm×185mm×150mm) were prepared for each group and removed after 28 days of standard curing. The specimens were installed on a concrete permeability tester, and the test was conducted using a stepwise pressurization method. The initial water pressure was 0.1MPa, and the pressure was increased by 0.1MPa every 8 hours until water seepage appeared at the end face of the specimen. The maximum water pressure value at this point was recorded. The specimen was then split along its height, and the average seepage height was measured.

[0108] II. Corrosion Inhibition Efficiency Test of Reinforced Concrete

[0109] The experiment was conducted in accordance with the standard JGJ / T192-2009 "Technical Specification for Application of Corrosion Inhibitors for Steel Reinforcing Bars".

[0110] First, prepare multiple sets of standard-sized reinforced concrete prism specimens. The specimen size is 100mm×100mm×300mm. A Φ10mm×280mm HRB400 grade steel bar is embedded in the center of each specimen. The two ends of the steel bar protrude 50mm from the specimen for electrode connection. The surface of the steel bar is sanded to remove rust and then wiped clean with ethanol.

[0111] The baseline group consisted of ordinary concrete without any added rust inhibitor. The experimental and control groups were prepared with rust inhibitors from Examples 1-3 and Comparative Examples 1-6, respectively, at a dosage of 3% of the cement weight. A blank control group without rust inhibitor was also prepared, with three specimens in each group. After 28 days of standard curing, all specimens were immersed in a 3.5% sodium chloride solution, with the solution level 20 mm above the top surface of the specimens. Linear polarization testing was performed using an electrochemical workstation. During the test, the reinforcing steel in the specimen was used as the working electrode, a saturated calomel electrode as the reference electrode, and a platinum sheet as the auxiliary electrode. The scan rate was 0.167 mV / s. The corrosion current density (Icorr) of the reinforcing steel was measured and recorded. The rust inhibition efficiency was determined according to the formula. The corrosion inhibition efficiency was calculated, where I0 is the corrosion current density of the steel bars in the blank control group and I1 is the corrosion current density of the steel bars in the group with corrosion inhibitor.

[0112] III. Concrete Resistance to Chloride Ion Attack Test

[0113] The experiment was conducted in accordance with the GB / T50082-2009 standard "Rapid Chloride Ion Migration Method (RCM)".

[0114] The chloride ion diffusion coefficient of concrete was tested using the rapid chloride ion migration method. Specimen preparation was the same as for the impermeability test, with consistent concrete mix proportions and rust inhibitor dosages. Three cylindrical specimens (Φ100mm × 50mm) were prepared for each group. After standard curing for 28 days, the sides of the specimens were sealed with epoxy resin, leaving only the top and bottom ends as ion migration surfaces. The specimens were installed in the RCM testing apparatus, with the upper side serving as the anode chamber filled with 0.3mol / L sodium hydroxide solution and the lower side as the cathode chamber filled with 10% sodium chloride solution. A 60V DC voltage was applied between the anode and cathode, and the testing apparatus was placed in a 20℃ constant temperature water bath. After 6 hours of operation, the power was cut off, and a Φ10mm core sample was drilled along the specimen's axis. Thin slices were cut every 2mm along the length of the core sample, and the chloride ion concentration of each slice was determined using silver nitrate titration. The chloride ion diffusion coefficient of the concrete was calculated using Fick's second law.

[0115] The results of the key performance tests of Examples 1-3 and Comparative Examples 1-6 are shown in Table 1.

[0116] Table 1:

[0117]

[0118] In summary:

[0119] As can be seen from Examples 1-3 and Comparative Example 1, and Table 1, active silica micropowder can react with cement hydration products through a pozzolanic reaction, generating more hydrated calcium silicate gel to fill the pores inside the concrete and improve its density. While ultrafine limestone powder has some filling effect, it lacks pozzolanic activity and cannot supplement gel formation. Therefore, the loss of active silica micropowder leads to a decrease in concrete density, resulting in weakened impermeability, easier chloride ion intrusion, and ultimately affecting the corrosion inhibition effect on steel reinforcement. This demonstrates the crucial role of active silica micropowder in improving concrete density and assisting in corrosion inhibition.

[0120] Combining Examples 1-3 and Comparative Example 2 with Table 1, it can be seen that sodium molybdate and calcium nitrate, as inorganic corrosion inhibitors, can form a synergistic effect with amino alcohol-based organic corrosion inhibitors. The organic corrosion inhibitors adsorb onto the surface of the reinforcing steel to form a protective film, while the inorganic corrosion inhibitors inhibit the electrochemical corrosion reaction on the surface of the reinforcing steel through ion exchange. After removing the inorganic corrosion inhibitors, the organic corrosion inhibitors alone are insufficient to fully inhibit steel corrosion, resulting in a significant decline in the corrosion inhibition effect. Since the impermeability of concrete mainly depends on the compaction effect of raw materials such as active silica micropowder and sulfoaluminate cement clinker, the impermeability performance of Comparative Example 2 is similar to that of Example 1. This also indicates that the core function of inorganic corrosion inhibitors is concentrated on inhibiting steel corrosion, which differs from the factors affecting impermeability performance.

[0121] Combining Examples 1-3 and Comparative Example 3 with Table 1, it can be seen that sulfoaluminate cement clinker exhibits rapid hardening characteristics, generating denser hydration products during the hydration process, which helps to rapidly improve the early-stage density of concrete. In contrast, ordinary silicate cement clinker has a slower hydration rate, and the density of its hydration products is relatively lower. This difference directly leads to a decrease in the impermeability of concrete. Furthermore, the reduced density makes it easier for chloride ions to penetrate, worsening the corrosive environment of the reinforcing steel and ultimately affecting the rust-inhibiting effect. This indicates that sulfoaluminate cement clinker plays a crucial supporting role in building the early-stage density of concrete and its subsequent corrosion and rust-inhibiting properties.

[0122] As can be seen from Examples 1-3 and Comparative Example 4, and Table 1, ultrafine limestone powder, with its small particle size and high purity, can play a fine filling role, filling the tiny pores formed inside the concrete due to insufficient hydration and reducing porosity. Ordinary quartz sand powder, on the other hand, has lower purity and larger particle size, resulting in limited filling effect and failing to effectively reduce internal pores in concrete. Therefore, Comparative Example 4 exhibits weakened impermeability, easier chloride ion penetration, and a decreased corrosion inhibition effect on reinforcing steel. This demonstrates the key value of ultrafine limestone powder in filling concrete pores and improving its impermeability and resistance to chloride ion erosion.

[0123] As can be seen from Examples 1-3 and Comparative Example 5, and Table 1, the pretreatment grinding, active component dispersion, and segmented compounding steps in Example 1 are all aimed at ensuring uniform mixing of the powder raw materials and avoiding agglomeration caused by differences in raw material density and particle size. One-time mixing, on the other hand, easily leads to raw material agglomeration and reduced mixing uniformity. This inhomogeneity can result in insufficient local gel formation and uneven pore distribution during concrete hydration, leading to weakened impermeability and reduced rust inhibition. This demonstrates that a segmented fine mixing process is crucial for ensuring uniform mixing of raw materials and improving the performance of the final product.

[0124] Combining Examples 1-3 and Comparative Example 6 with Table 1, it can be seen that the atomized spraying in Example 1 allows the modifier to be uniformly coated on the surface of the composite powder, ensuring that each powder particle can come into contact with the modifier. Direct mixing, however, makes it difficult to achieve uniform distribution of the modifier; some powder particles may not be fully coated, leading to uneven distribution of water-repellent and corrosion-inhibiting components in the concrete. Areas with insufficient water-repellent components are prone to water seepage, while areas with insufficient corrosion-inhibiting components are prone to steel corrosion. Therefore, Comparative Example 6 exhibits weakened impermeability and reduced corrosion inhibition effect. This demonstrates the importance of the atomized liquid phase surface modification process in ensuring uniform distribution of the modifier and maximizing its water-repellent and corrosion-inhibiting effects.

[0125] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing an enhanced concrete corrosion inhibitor, characterized in that, Includes the following steps: S1. Pretreatment and coarse grinding: 15-30 parts of sulfoaluminate cement clinker and 10-30 parts of ultrafine limestone powder are put into a grinding equipment and ground together for 25-40 minutes at a speed of 250-350 r / min to obtain mixed base material A. S2. Dispersion of active components: 25-45 parts of active silica micro powder, 5-15 parts of calcium nitrate, and 3-10 parts of sodium molybdate are put into a high-efficiency vortex disperser and dry dispersed at a speed of 1200-1800 r / min for 15-25 minutes until the coefficient of variation of the mixing uniformity is less than 5%, thus obtaining mixed active component B. S3. Segmented fine compounding: The mixed base material A is added to the dispersion equipment containing the mixed active component B in three parts. After each addition, the mixture is stirred at a speed of 800-1000 r / min for 10-15 minutes to finally form the composite powder C. S4. Liquid phase surface modification: 4-12 parts of amino alcohol organic rust inhibitor are premixed with 0.5-2.0 parts of hydroxyl-terminated polydimethylsiloxane, and then sprayed evenly onto the surface of composite powder C in a rolling state through an atomizing nozzle. During the spraying process, the container temperature is maintained at 45-55℃. S5. Homogenization and maturation: The material after liquid phase surface modification is transferred to the homogenization chamber and allowed to stand and mature at a constant temperature of 50-60℃ for 24-36 hours. S6. Final mixing: Transfer the matured material together with 0.3-1.5 parts of hydroxypropyl methylcellulose into a mixing device and mix at a low speed of 50-60 r / min for 45-60 minutes until the uniformity is greater than 98%, which yields the final product.

2. The method for preparing an enhanced concrete corrosion inhibitor according to claim 1, characterized in that: In step S1, the grinding media used in the grinding equipment is zirconia balls, with a particle size ratio of 40% balls with a diameter of 3mm and 60% balls with a diameter of 5mm.

3. The method for preparing an enhanced concrete corrosion inhibitor according to claim 1, characterized in that: In step S4, the working pressure of the atomizing nozzle is 0.3-0.6 MPa, and the atomized droplet particle size is no greater than 50 μm.

4. The method for preparing an enhanced concrete corrosion inhibitor according to claim 1, characterized in that: In step S5, the relative humidity of the homogenization chamber is controlled below 40%.

5. The method for preparing an enhanced concrete corrosion inhibitor according to claim 1, characterized in that: The specific surface area of ​​the active silica micro powder is 18,000-25,000 m² / kg, and the silica content is not less than 92%; the viscosity of the hydroxypropyl methylcellulose is 40,000-100,000 mPa·s; and the calcium carbonate content in the ultrafine limestone powder is not less than 95%.

6. The method for preparing an enhanced concrete corrosion inhibitor according to claim 1, characterized in that: The amino alcohol organic rust inhibitor is at least one of diethanolamine, triethanolamine and aminobutanol.

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