Coated sustained-release medium transport inhibitor, preparation method and application

Abstract

The application discloses a coated slow-release medium transmission inhibitor, a preparation method and application, and belongs to the technical field of admixtures for building materials. The preparation raw material of the coated slow-release medium transmission inhibitor comprises the following components: a pore densification component, a pore film forming component, a particle coating component, a dispersing component and a mineral admixture. The pore densification component is a dense filler; the pore film forming component is a redispersible rubber powder; the particle coating component is a lipophilic organic substance with a vaporization temperature of 60-300 DEG C; and the particle coating component is uniformly and densely coated on the surfaces of the pore densification component and the pore film forming component. The coated slow-release medium transmission inhibitor can be used in the reinforced concrete structures of tunnels, mines, sewage treatment, pipeline corrosion prevention and municipal, energy and other projects in water-rich or salt-rich environments, is used for inhibiting the transmission of corrosive medium to the inside of the concrete, and has a significant inhibiting effect on the dissolution of calcium ions in the concrete.

Description

Technical Field

[0001] This invention belongs to the field of building material admixtures technology, specifically relating to a coated slow-release medium transport inhibitor, its preparation method, and its application. Background Technology

[0002] For reinforced concrete projects that are underground for extended periods, such as tunnels, mines, municipal works, energy projects, and wastewater treatment facilities, the reinforced concrete structure is inevitably subject to long-term erosion by groundwater or sewage. This leads to prominent problems such as leakage and corrosion damage. Corrosive media can seep into the concrete along with water, causing corrosion and damage; calcium ions in the concrete can also dissolve with groundwater, causing leakage. It is estimated that approximately 90% of tunnels worldwide experience leakage. In water-rich environments, the initial support concrete of tunnels is prone to calcium ion dissolution and precipitation due to its high water-cement ratio, high cement content, and rapid setting time, resulting in concrete damage and deterioration. The deterioration mechanism involves unhydrated cement and soluble cement hydration products being washed away by flowing water, releasing calcium ions which then migrate into the environment under the influence of internal and external concentration differences, gradually increasing the porosity and reducing the strength of the initial support concrete. Furthermore, the dissolution of hydration products leads to a decrease in the pH of the pore fluid, increasing the risk of corrosion of the steel arch frame. At the same time, a large number of calcium ions precipitate and react in the tunnel drainage system to form calcium carbonate crystals that block the drainage pipes (ditches), resulting in slippery tunnel surfaces and damage to electrical components, thereby endangering the long-term driving safety and structural durability of the tunnel.

[0003] Current research focuses on improving the resistance of concrete to media transport and calcium ion dissolution, primarily through methods such as reducing the water-cement ratio, adding mineral admixtures, and enhancing hydrophobicity. The research results of Yu et al. (Construction Building Material, 2018, 161:509-518) show that compared to concrete specimens with a water-cement ratio of 0.5, concrete with a water-cement ratio reduced to 0.35 exhibits significant improvements in mass loss, calcium hydroxide leaching, and porosity. However, for tunnel initial support concrete, a relatively high water-cement ratio is generally used to facilitate shotcreting, and reducing the water-cement ratio can affect the concrete's workability. Existing research indicates that adding mineral admixtures can reduce the amount of Ca(OH)₂ in the hydration products, refine the concrete pores, and improve its resistance to dissolution. Han et al. (Construction & Building Materials, 2014, 68(oct.15):630-636) studied the effects of fly ash and slag on the corrosion resistance of concrete. The results showed that concrete with a fly ash content of less than 65% (mass fraction) exhibited better corrosion resistance, while concrete with a slag content of less than 70% (mass fraction) showed good long-term corrosion resistance. Wolfram et al. (Cement & Concrete Composites, 2015) demonstrated that reducing the water-cement ratio and adding fly ash and slag can improve the corrosion resistance of concrete, with fly ash content not exceeding 40% (mass fraction) and slag content not exceeding 70% (mass fraction). However, due to the low hydration degree of the cementitious system, the early strength of the initial support concrete will decrease, and the setting time will be prolonged, thus adversely affecting tunnel construction. Besides mineral admixtures, materials that improve the compactness of concrete include nanomaterials. Common nanomaterials include nano-silica, nano-titanium dioxide, and nano-calcium carbonate. Jalal et al. (Materials and Design, 2012, 34:389-400.) studied the effect of nano-silica on the properties of self-compacting concrete. The results showed that the incorporation of nano-silica resulted in a finer and denser pore structure in the concrete, and improved concrete strength, but its effect on inhibiting media transport was relatively limited.

[0004] Patent CN108129052 B discloses the application of fatty acid esters as admixtures for resisting rainwater erosion in permeable concrete, and the admixtures themselves. The fatty acid esters are long-chain organic carboxylic acid esters. Due to the strong alkalinity of concrete, they can hydrolyze to release organic carboxylic acids, which react with calcium ions in the hydration products to generate calcium fatty acid-based hydrophobic substances, thereby enhancing the rainwater erosion resistance of permeable concrete. Admixtures for resisting rainwater erosion are prepared based on different functional components. However, the fatty acid esters described in this invention have poor hydrophilicity, which affects the dispersion of effective components during concrete mixing. Furthermore, the calcium carboxylic acid generated by the reaction of the long-chain hydrophobic substances negatively impacts the microstructure and mechanical properties of concrete, thus affecting the practical application effect. CN114890734A discloses a cement-based material for concrete that resists calcium dissolution. This material is prepared by mixing a two-component material with water. It inhibits calcium ion dissolution by applying the mixture to the concrete surface after mixing. It boasts advantages such as good workability, high strength, good compatibility with the matrix, rapid setting and hardening, low calcium dissolution in soft water, resistance to peeling, convenient transportation, and low cost. However, existing anti-media transport inhibition technologies still suffer from insufficient anti-dissolution effects in engineering applications. Directly added nanomaterials affect concrete workability and hinder construction. Some admixtures significantly impact concrete workability and mechanical properties, particularly in inhibiting calcium ion dissolution. Furthermore, in water-rich or salt-rich environments, water erosion and salt attack greatly exacerbate corrosion damage to the concrete structure, making it more susceptible to calcium ion dissolution. This presents new challenges to concrete's resistance to calcium ion dissolution. Summary of the Invention

[0005] To better improve the resistance of concrete to media transport and calcium ion dissolution, and enhance its long-term corrosion resistance, especially its resistance to calcium ion leaching in water-rich or salt-rich environments, this invention provides a coated slow-release media transport inhibitor, its preparation method, and its application. This inhibitor is applied to reinforced concrete structures in water-rich or salt-rich environments such as tunnels, mines, sewage treatment plants, pipeline corrosion protection, and municipal and energy projects to inhibit the transport of corrosive media into the concrete, while also significantly inhibiting the dissolution of calcium ions in the concrete.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] An encapsulated sustained-release mediator delivery inhibitor, the raw materials for its preparation include the following components in percentage mass ratio:

[0008] Porous dense component…………………………10%~50%,

[0009] Pore ​​film-forming components…………………………10%~30%,

[0010] Particle-coated components: 0.5%–10%

[0011] Dispersed components………………………………0.1%~5%,

[0012] The remainder is mineral admixtures;

[0013] The dense pore component is a dense filler; the film-forming pore component is a redispersible adhesive powder; the particulate coating component is an oleophilic organic material with a vaporization temperature of 60–300°C; the particulate coating component uniformly and densely coats the surfaces of the dense pore component and the film-forming pore component.

[0014] Preferably, the particulate coating component can be vaporized and coated on the surface of the porous dense component and the porous film-forming component to form a uniform and dense protective film, thereby achieving the slow release of the dense filler and redispersible adhesive powder and the long-term inhibition of calcium ion dissolution.

[0015] Preferably, both the pore-dense component and the pore-film-forming component coated by the particle coating component have a spherical or near-spherical structure; the spherical or near-spherical structure is more conducive to the application of powder particles in concrete systems, as it not only does not affect the fluidity of concrete, but can also appropriately improve the mechanical properties of concrete.

[0016] Preferably, in the raw materials for preparing the coated slow-release media transport inhibitor, the percentage mass ratio of the particle coating component is 0.5% to 3.5%. The material composition and amount of the particle coating component are closely related to the thickness and density of the coating film, and also closely related to the release process after participating in cement hydration. Generally, the higher the percentage mass ratio of the coating component, the thicker the coating film on the particle surface and the better the density. However, an excessively thick coating film is not conducive to compaction and the later release of the film-forming component. On the other hand, the lower the percentage mass ratio, the thinner the coating film, which is more likely to be released earlier in the strongly alkaline environment of cement, leading to incomplete cement hydration and affecting the density of the hydration product structure and the long-term resistance to media erosion.

[0017] Optionally, the dense filler is one or a combination of several solid particles selected from silica fume, dense silica fume, nano-silica, nano-calcium carbonate, and nano-titanium dioxide; further, the specific surface area of ​​the silica fume and dense silica fume is 20,000–25,000 m². 2 / kg, the particle size of the nano-silica, nano-calcium carbonate, and nano-titanium dioxide is between 10 and 1000 nm, more preferably 10 to 500 nm. Besides the composition and structure of the nanoparticles themselves significantly affecting the porosity and density of concrete, the size of the nanoparticles also has a significant impact on the pore structure and interfacial transition zone of concrete. Optimization of pore density and interfacial transition zone greatly improves resistance to media penetration. This invention optimizes the nanoparticle size through comparison, and, based on different concrete mix proportions, can selectively combine the types of nanomaterials with particle sizes and compositions to achieve better resistance to media penetration.

[0018] Preferably, the redispersible polymer powder includes, but is not limited to, VAE polymer powder, styrene-based polymer powder, etc. This type of redispersible polymer powder has good compatibility with the strongly alkaline system of cement-based materials, can participate in the cement hydration process, and can be uniformly distributed on the surface of hydration products. After release in strong alkaline and strong salt systems, it has the characteristics of rapid dissolution, efficient dispersion, and uniform distribution, thereby more effectively improving the stability of the hydration products themselves and effectively inhibiting the calcium ion dissolution rate in hydration products under strong permeable media systems.

[0019] Preferably, the oleophilic organic material includes, but is not limited to, one or more combinations of paraffin wax, stearic acid, organosiloxanes, etc., and coating materials with similar performance characteristics can also be used. The coating material has the characteristic of vaporization film formation, and by controlling the vaporization film formation temperature, the percentage mass content of the film-forming substance, and the mixing process, the uniformity and density of the film formed on the surface of the coated particles, as well as the control of the coating film thickness, can be achieved. This allows for the slow release of the coated particles, preventing the dense particles and film-forming components from prematurely participating in cement hydration and affecting the structure and pore density of the hydration products.

[0020] Preferably, the dispersing component is a powder-type water-reducing agent, including but not limited to one or a combination of naphthalene-based, melamine-based, and polycarboxylate-based water-reducing agents.

[0021] Preferably, the mineral admixture is one or a combination of fly ash, mineral powder, and stone powder.

[0022] On the other hand, the present invention also provides a method for preparing the encapsulated sustained-release mediator delivery inhibitor, specifically including the following steps:

[0023] (1) Add the pore-dense component and the pore-film-forming component to the mixer, stir evenly, and then heat the mixer to 60-300°C. Slowly add the vaporized particle coating component, control the temperature in the mixer so that the added particle coating component remains in a vaporized state, and through the mixing process of the material, the oleophilic organic matter forms a uniform adsorption on the surface of the solid powder particles. Then slowly lower the temperature so that the vaporized film adsorbed on the particle surface gradually solidifies and forms a uniform and stable coating film.

[0024] (2) Reduce the temperature inside the mixer to below 60°C, add the dispersing components and mineral admixtures to the mixer, continue to mix evenly and then discharge the material to obtain the coated slow-release medium transport inhibitor.

[0025] The preparation process of the coated sustained-release media delivery inhibitor of this invention includes several steps, such as mixing dense filler and redispersible polymer powder, surface coating, and mixing with dispersion components and mineral admixtures. The powder mixing process is carried out in a mixer. The coating process involves vaporizing the coating material through heating, adding it to the mixer via a vaporization atomization device, and uniformly distributing it in the mixer at a high temperature. A coating film is formed through adsorption on the surfaces of the dense filler and redispersible polymer powder. The coating material is then solidified on the particle surface through gradual cooling, achieving uniform particle coating. Gradual cooling can be achieved through air cooling or liquid cooling, controlled by process equipment. The cooling process can be selected and optimized according to the characteristics of the coating material.

[0026] On the other hand, the present invention also provides the application of the coated slow-release media transport inhibitor, which can be applied to reinforced concrete structures in water-rich or salt-rich environments such as tunnels, sewage treatment, pipeline corrosion protection, and municipal and energy projects to inhibit the transport of corrosive media and the dissolution of calcium ions in concrete; the coated slow-release media transport inhibitor is added during concrete mixing, with an addition amount of 5% to 10% of the amount of cementitious materials; the mixing time can be appropriately extended by 30 seconds to 1 minute during the mixing process to ensure that the calcium ion corrosion inhibitor is fully mixed with the concrete mix, while strictly controlling the amount of water used in the concrete to ensure that the concrete with the added calcium ion corrosion inhibitor is mixed according to the design proportion.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The encapsulated slow-release medium transport inhibitor includes pore-dense and pore-film-forming components. The pore-dense component can fill the pores of hydration products during the hydration process, enhancing the compactness of the concrete itself. The pore-film-forming component can form an organic film layer inside the pores during the hydration process. This film layer can effectively inhibit the interaction between water and other corrosive salt media and cement hydration products, thereby reducing the calcium ion dissolution rate and corrosion rate in cement hydration products. Through the synergistic effect of the compaction of concrete pores and the film formation inside the pores, the concrete's resistance to calcium ion dissolution can be effectively enhanced.

[0029] (2) In addition, the coated slow-release media transport inhibitor of the present invention also performs surface modification treatment on the pore compaction component and the pore film-forming component through a special vaporization treatment preparation process. After surface treatment, the pore compaction component and the pore film-forming component can slow down the direct interaction between the pore compaction component and the hydration product in the early stage of cement hydration, thereby avoiding the influence of the pore compaction component and the pore film-forming component on the workability and early mechanical properties of concrete. After surface coating treatment, as cement hydration proceeds, the pore compaction component and the pore film-forming component are gradually released and then fill the pores of the relatively fully hydrated concrete and perform film modification inside the pores, thereby achieving better concrete performance development, long-term resistance to media transport and resistance to corrosion inhibition.

[0030] (3) Furthermore, the coated sustained-release media transport inhibitor of the present invention is processed by a special vaporization process. The functional components include particles and dispersion components of different sizes, including but not limited to nanoparticles and other powder particles. The combination of dense particles of different sizes can further optimize and enhance the density of hydration products, thereby achieving better media transport inhibition and calcium ion corrosion inhibition effects. Detailed Implementation

[0031] The following examples describe in more detail the preparation of powder-particle-coated sustained-release media delivery inhibitors according to the method of the present invention. These examples are given by way of illustration and are intended to enable those skilled in the art to understand the content of the invention and implement it accordingly, but these examples are in no way limiting the scope of the invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

[0032] In all examples and comparative examples, the parts by weight of each raw material are all parts by weight. The naphthalene-based and polycarboxylate dispersants were produced by Jiangsu Subote New Material Co., Ltd., with models JM-A and PCA-I respectively. The powdered melamine water-reducing agent was produced by BASF, with model F-15. The dispersants described in this invention are not limited to the above manufacturers and models; other dispersants with the same function can also be used as materials in the examples.

[0033] Example 1

[0034] Add a surface area of ​​23500m² to the mixer 2 50 parts / kg of silica fume and 15 parts of VAE latex were mixed in a mixer for 30 minutes. After uniform mixing, the mixer was heated to 220°C. 5 parts of liquid paraffin were vaporized using a spray device and introduced into the mixer. The powder and vaporized paraffin were mixed at 120°C for another 30 minutes. Then, the temperature was lowered to allow the vaporized paraffin to fully adsorb onto the surface of the powder particles and gradually form a coating layer. When the temperature dropped to 50°C, 4.5 parts of powdered naphthalene-based water-reducing agent and 25.5 parts of fly ash were added to the mixer. Mixing continued for 40 minutes until uniform, and then the mixture was discharged to obtain the powder particle-coated slow-release media transport inhibitor S1.

[0035] Example 2

[0036] Add a specific surface area of ​​20000 m² to the mixer 2 37 parts / kg of silica fume and 30 parts of VAE latex were mixed in a mixer for 30 minutes. After uniform mixing, the mixer was heated to 250°C. Three parts of liquid stearic acid were vaporized using a spray device and introduced into the mixer. At 250°C, the powder material and vaporized stearic acid were mixed for another 30 minutes. Then, the temperature was lowered to allow the vaporized stearic acid to fully adsorb onto the surface of the powder particles and gradually form a coating layer. When the temperature dropped to 40°C, three parts of powdered polycarboxylate superplasticizer and 27 parts of mineral powder were added to the mixer. Mixing continued for another 50 minutes until uniform, and then the mixture was discharged to obtain the powder particle-coated slow-release media transport inhibitor S2.

[0037] Example 3

[0038] 20 parts of 50nm nano-silica and 20 parts of styrene-butadiene resin powder were added to a mixer and stirred for 40 minutes. After uniform mixing, the mixer was heated to 150°C. Three parts of liquid dodecyltriethylsiloxane were vaporized using a spray device and introduced into the mixer. At 250°C, the powder material and the vaporized dodecyltriethoxysiloxane were continued to mix for 40 minutes. Then, the temperature was lowered to allow the vaporized dodecyltriethylsiloxane to fully adsorb onto the surface of the powder particles and gradually form a coating layer. When the temperature dropped to 30°C, 2.5 parts of powdered melamine water-reducing agent, 24.5 parts of mineral powder, and 30 parts of fly ash were added to the mixer. Mixing continued for 30 minutes until uniform, and then the mixture was discharged to obtain powder particle-coated slow-release media transport inhibitor S3.

[0039] Example 4

[0040] Add 20 parts of 15nm nano-silica and 20 parts of 25000m² specific surface area to the mixer. 225 parts of high-density silica fume and VAE latex powder (per kg) were mixed in a mixer for 50 minutes. After thorough mixing, the mixer was heated to 200°C. 3.5 parts of liquid paraffin were vaporized using a spray device and introduced into the mixer. At 250°C, the powder materials and vaporized paraffin vapor were mixed for 30 minutes. Then, the temperature was lowered to allow the vaporized paraffin to fully adsorb onto the surface of the powder particles and gradually form a coating layer. When the temperature dropped to 30°C, 3.5 parts of powdered melamine water-reducing agent and 27.5 parts of stone powder were added to the mixer. Mixing continued for 60 minutes until thoroughly mixed, and then the mixture was discharged to obtain powder particle-coated slow-release media transport inhibitor S4.

[0041] Example 5

[0042] Add 15 parts of 100nm nano-titanium dioxide and 20 parts of VAE latex powder to a mixer and stir for 30 minutes. After stirring evenly, heat the mixer to 280℃. Liquefy 1 part of stearic acid through a spray device and introduce it into the mixer. Continue mixing the powder material and the vaporized stearic acid vapor at 280℃ for 30 minutes. Then begin cooling to allow the vaporized stearic acid to fully adsorb onto the surface of the powder particles and gradually form a coating layer. When the temperature drops to 40℃, add 0.5 parts of powdered polycarboxylate superplasticizer, 43.5 parts of fly ash, and 20 parts of mineral powder to the mixer and continue mixing for 60 minutes. After mixing evenly, discharge the material to obtain powder particle-coated slow-release media transport inhibitor S5.

[0043] Example 6

[0044] Add 25 parts of 500nm nano-calcium carbonate and 10 parts of Formosa Plastics ABS high-adhesion powder to a mixer and stir for 50 minutes. After stirring evenly, heat the mixer to 180°C. Liquefy 2.5 parts of lauric acid through a spray device and introduce it into the mixer. Continue mixing the powder materials and vaporized lauric acid vapor at 180°C for 30 minutes. Then begin cooling to allow the vaporized lauric acid to fully adsorb onto the surface of the powder particles and gradually form a coating layer. When the temperature drops to 40°C, add 1 part of powdered polycarboxylate superplasticizer, 30 parts of fly ash, and 31.5 parts of stone powder to the mixer and continue mixing for 30 minutes. After mixing evenly, discharge the material to obtain powder particle-coated slow-release media transport inhibitor S6.

[0045] Comparative Example 1

[0046] This comparative example is based on Example 2, except that the porous dense component was not coated, while all other conditions are the same as in Example 2.

[0047] Add 30 parts of VAE latex to the mixer and stir for 30 minutes. After thorough mixing, heat the mixer to 250°C. Vaporize 3 parts of stearic acid liquid using a spray device and introduce it into the mixer. Continue mixing the powder material and the vaporized stearic acid at 250°C for 30 minutes. Then begin cooling to allow the vaporized stearic acid to fully adsorb onto the surface of the powder particles and gradually form a coating layer. When the temperature drops to 40°C, add a 20,000 m² specific surface area... 2 Mix 37 parts / kg of silica fume, 3 parts of powdered polycarboxylate superplasticizer, and 27 parts of mineral powder for 50 minutes. After thorough mixing, discharge the mixture to obtain powder particle-coated slow-release media transport inhibitor D1.

[0048] Comparative Example 2

[0049] This comparative example is based on Example 2, except that the porous film-forming components are not coated, while all other conditions are the same as in Example 2.

[0050] Add a specific surface area of ​​20000 m² to the mixer 2 37 parts / kg of silica fume were mixed in a mixer for 30 minutes. After thorough mixing, the mixer was heated to 250°C. Three parts of liquid stearic acid were vaporized using a spray device and introduced into the mixer. At 250°C, the powder material and vaporized stearic acid were mixed for another 30 minutes. Then, the temperature was lowered to allow the vaporized stearic acid to fully adsorb onto the surface of the powder particles and gradually form a coating layer. When the temperature dropped to 40°C, 30 parts of VAE latex, 3 parts of powdered polycarboxylate superplasticizer, and 27 parts of mineral powder were added to the mixer. Mixing continued for another 50 minutes until thoroughly mixed, then the mixture was discharged to obtain powder particle-coated slow-release media transport inhibitor D2.

[0051] Comparative Example 3

[0052] This comparative example is based on Example 2, except that the particulate-coated component was not vaporized, while all other conditions are the same as in Example 2.

[0053] Add a specific surface area of ​​20000 m² to the mixer 2 37 parts of silica fume and 30 parts of VAE latex per kg were mixed in a mixer for 30 minutes. After mixing evenly, 3 parts of stearic acid liquid were introduced into the mixer, and the powder materials and paraffin were mixed for another 30 minutes to allow the paraffin to be adsorbed onto the surface of the powder particles. The temperature was raised to 40°C, and 3 parts of powdered polycarboxylate superplasticizer and 27 parts of mineral powder were added to the mixer. The mixture was continued to mix for another 50 minutes. After mixing evenly, the mixture was discharged to obtain powder particle coated slow-release media transport inhibitor D3.

[0054] Application Examples

[0055] The coated slow-release media transport inhibitor of this invention is mainly applied to reinforced concrete structures in water-rich or salt-rich environments such as tunnels, mines, sewage treatment plants, pipeline corrosion protection, and municipal and energy projects. It is used to inhibit the transport of corrosive media into the concrete interior and has a significant inhibitory effect on the dissolution of calcium ions in the concrete. The coated slow-release media transport inhibitor is added during the concrete mixing process, with the dosage being 5% to 10% of the amount of cementitious materials. The mixing time can be appropriately extended by 30 seconds to 1 minute during the mixing process to ensure that the media transport inhibitor is fully mixed with the concrete mix. At the same time, the amount of water used in the concrete is strictly controlled to ensure that the concrete with the added media transport inhibitor is mixed according to the design proportion.

[0056] Taking the application of alkali-resistant concrete in tunnel structures as an example, alkali-resistant materials are applied to shotcrete to inhibit the dissolution of calcium ions in the shotcrete through a coated slow-release medium transport inhibitor. The selected raw materials include silicate cement (PO 42.5), large aggregates (basalt 10-20mm), river sand (medium sand), accelerator (alkali-free liquid), and inhibitors (different coated slow-release medium transport inhibitor samples prepared in the embodiments of this invention). The concrete mix proportions are shown in Table 1. To ensure a consistent water-cement ratio, the amount of silicate cement is deducted by an equal amount when adding the powdered coated slow-release medium transport inhibitor. To better compare the inhibitory effect of this invention on the dissolution of calcium ions in tunnel structure concrete, commonly used dense silica fume (SF) and samples from Comparative Examples 1-3 (D1-D3) are selected as control samples.

[0057] Table 1 Concrete mix proportions (kg / m³) 3 )

[0058]

[0059] Molded concrete was used to study the effects of different comparative samples and the samples prepared in this invention on the sulfate resistance, chloride ion penetration resistance, and calcium ion dissolution of concrete. The sulfate resistance coefficient and chloride ion diffusion coefficient were tested according to the methods specified in GB / T 50082-2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete". The calcium ion dissolution rate for corrosion resistance was tested by immersion method, measuring the ratio of calcium ion dissolution to total calcium ion content in the concrete after 14 days. The experimental results are shown in Table 2.

[0060] Table 2. Concrete's resistance to media penetration and calcium ion leaching (kg / m²) 3 )

[0061]

[0062]

[0063] Table 2 shows that SF, D1, D2, D3, and the coated slow-release media transport inhibitor prepared in this invention all have significant effects in inhibiting sulfate corrosion, reducing the chloride ion diffusion coefficient, and reducing the calcium ion dissolution rate. Among them, the sample prepared in this invention has a more superior effect on improving various corrosion resistance properties. Moreover, after surface coating, the influence of nano-density and film-forming materials on the workability and mechanical properties of concrete is greatly reduced, especially in terms of reducing the chloride ion diffusion coefficient and calcium ion dissolution rate. The reduction in chloride ion diffusion coefficient and calcium ion dissolution rate further highlights the improvement and enhancement of the long-term corrosion resistance of concrete by this technology.

Claims

1. An encapsulated sustained-release mediator delivery inhibitor, characterized in that, Its preparation raw materials include the following components by percentage mass ratio: Porous dense component…………………………10%~50%, Pore ​​film-forming components…………………………10%~30%, Particle-coated components: 0.5%~10% Dispersed components………………………………0.1%~5%, The remainder is mineral admixtures; The porous compact component is a compact filler; The porous film-forming component is a redispersible adhesive powder; The particulate coating component is an oleophilic organic compound with a vaporization temperature of 60~300℃; The particulate coating component is uniformly and densely coated on the surfaces of the porous dense component and the porous film-forming component; The dense filler is one or a combination of several of the following: silica fume, nano silica, nano calcium carbonate, and nano titanium dioxide. The redispersible polymer powder is one of VAE polymer powder and styrene-based polymer powder; The particulate coating component is vaporized and uniformly coated on the surfaces of the dense porous component and the porous film-forming component.

2. The encapsulated sustained-release mediator delivery inhibitor according to claim 1, characterized in that, Both the porous dense component and the porous film-forming component coated by the particle coating component have spherical or near-spherical structures.

3. The encapsulated sustained-release mediator delivery inhibitor according to claim 1, characterized in that, In the raw materials for preparing the coated sustained-release media delivery inhibitor, the percentage mass ratio of the particulate coating component is 0.5% to 3.5%.

4. The encapsulated sustained-release mediator delivery inhibitor according to claim 1, characterized in that, The dense filler is dense silica ash.

5. The encapsulated sustained-release mediator delivery inhibitor according to claim 1, characterized in that, The specific surface area of ​​the silica fume is 20,000~25,000 m². 2 / kg.

6. The encapsulated sustained-release mediator delivery inhibitor according to claim 1, characterized in that, The particle size of the nano-silica, nano-calcium carbonate, and nano-titanium dioxide is between 10 and 1000 nm.

7. The encapsulated sustained-release mediator delivery inhibitor according to claim 1, characterized in that, The lipophilic organic compound is one or a combination of paraffin, stearic acid, and organosiloxane.

8. The encapsulated sustained-release media delivery inhibitor according to claim 1, characterized in that, The mineral admixture is one or a combination of fly ash, mineral powder, and stone powder.

9. The method for preparing the encapsulated sustained-release mediator delivery inhibitor according to any one of claims 1-8, characterized in that, Specifically, the steps include the following: (1) Add the pore-dense component and the pore-film-forming component to the mixer, stir evenly, and then heat the mixer to 60~300℃. Slowly add the vaporized particle coating component, control the temperature in the mixer so that the added particle coating component remains in a vaporized state, and through the mixing process of the material, the oleophilic organic matter forms a uniform adsorption on the surface of the solid powder particles. Then slowly lower the temperature so that the vaporized film adsorbed on the particle surface gradually solidifies and forms a coating film. (2) Reduce the temperature inside the mixer to below 60°C, add the dispersing components and mineral admixtures to the mixer, continue to mix evenly and then discharge the material to obtain the coated slow-release medium transport inhibitor.

10. The application of the encapsulated sustained-release mediator delivery inhibitor according to any one of claims 1-8, characterized in that, The encapsulated slow-release medium transport inhibitor is added during the concrete mixing process, and the amount added is 5% to 10% of the amount of cementitious materials.

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