A corrosion-resistant digital aggregate based on steric barrier and its preparation and application

Abstract

The present invention discloses a corrosion-resistant digital aggregate based on steric barrier and its preparation and application, comprising a mineralized aggregate blank and a first protective layer coated on the surface of the mineralized aggregate blank; the aggregate blank comprises a radio frequency unit and a second protective layer coated on the radio frequency unit; the raw materials of the first protective layer include a first protective agent, the first protective agent includes one or more of polyimide, fluorinated ethylene propylene copolymer, and soluble polytetrafluoroethylene; the raw materials of the second protective layer include a carbon mineralized material, a reinforcing agent, and a second protective agent, the second protective agent includes one or more of sodium tetraborate, sodium silicate, and sodium metaaluminate; the present application ensures the stability of digital aggregate intensity signal transmission at the physical and chemical levels through two layers of protection measures, which can effectively avoid the problem of reduced digital aggregate signal transmission performance caused by external corrosive substances.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent building materials, and in particular to a corrosion-resistant digital aggregate based on three-dimensional barrier and the preparation and application thereof. Background Art

[0002] Currently, most companies in the cement concrete precast component industry still rely on manual methods for marking and inventorying precast components. Faced with a large number of precast components, manual marking and inventorying are labor-intensive, inefficient, and prone to errors. Some companies also opt to affix QR codes to the surfaces of precast components to facilitate information-based management. However, due to the complex service environment, QR codes are easily damaged and detached, resulting in limited success.

[0003] Radio frequency technology, a method of communicating using electromagnetic waves, can be used to identify and trace concrete structures or components. However, when radio frequency chips are embedded in concrete, the shielding effect of concrete on electromagnetic waves significantly reduces the signal transmission distance. Furthermore, as the service life of concrete increases, corrosive substances from the outside can diffuse into the concrete through cracks or pores, corroding the radio frequency chips. Concrete components used in underground spaces, such as concrete pipes and segments, can also significantly reduce the lifespan of their internal radio frequency chips when corroded by groundwater, significantly reducing their signal transmission performance and seriously affecting the identification and traceability of concrete components.

[0004] Therefore, it is necessary to provide a solution to improve the corrosion resistance of radio frequency chips. Summary of the Invention

[0005] In view of this, the present application provides a corrosion-resistant digital aggregate based on three-dimensional barrier and its preparation and application, which are used to solve the problem of how to improve the corrosion resistance of radio frequency chips.

[0006] In order to achieve the above technical objectives, this application adopts the following technical solutions:

[0007] In the first aspect, the present application provides a corrosion-resistant digital aggregate based on three-dimensional barrier, comprising a mineralized aggregate blank and a first protective layer coated on the surface of the mineralized aggregate blank; the aggregate blank comprises a radio frequency unit and a second protective layer coated on the radio frequency unit; the raw materials of the first protective layer include a first protective agent, the first protective agent includes one or more of polyimide, fluorinated ethylene propylene copolymer, and soluble polytetrafluoroethylene; the raw materials of the second protective layer include a carbon mineralized material, a reinforcing agent, and a second protective agent, the second protective agent includes one or more of sodium tetraborate, sodium silicate, and sodium aluminate.

[0008] Preferably, the mass ratio of the radio frequency unit, the carbon mineralized material, the first protective agent, the second protective agent, and the reinforcing agent is 1:8-64:1-21:2-40:1-11.

[0009] Preferably, the carbon mineralized material includes one or more of tricalcium silicate, gamma-type dicalcium silicate, beta-type dicalcium silicate, monocalcium silicate, tricalcium disilicate, calcium hydroxide, magnesium hydroxide, calcium oxide, and magnesium oxide; and the particle size of the carbon mineralized material is 75-150 μm.

[0010] Preferably, the enhancer includes one or more of chitosan, sodium alginate, polyethylene glycol, and polyvinyl alcohol.

[0011] Preferably, the radio frequency unit includes a radio frequency chip and a radio frequency antenna connected to the radio frequency chip.

[0012] In a second aspect, the present application provides a method for preparing a corrosion-resistant digital aggregate based on steric barrier, comprising the following steps:

[0013] S1. The carbon mineralized material, the second protective agent, the reinforcing agent and water are mixed to obtain a mixture;

[0014] S2. In a mold, the RF unit is embedded in the mixture and pressed to obtain an aggregate body;

[0015] S3. Under a carbon dioxide atmosphere, the aggregate body is mineralized to obtain a mineralized aggregate body;

[0016] S4. Apply the first protective agent to the surface of the mineralized aggregate body, and after drying to form a film, obtain a corrosion-resistant digital aggregate based on three-dimensional barrier.

[0017] Preferably, in step S2, the pressing pressure is 10-60 MPa.

[0018] Preferably, in step S3, the partial pressure of carbon dioxide is 0.1-0.3 MPa, the volume concentration of carbon dioxide is 20-99.9%, the mineralization temperature is 5-90° C., and the mineralization time is 12-48 h.

[0019] Preferably, in step S4, the coating thickness is 0.1-0.5 mm, and the film forming time is 1-3 min.

[0020] In a third aspect, the present application provides an application of a corrosion-resistant digital aggregate based on three-dimensional barrier in the field of concrete components and / or cast-in-place structures.

[0021] The beneficial effects of the present application are as follows: the present application protects the digital aggregate at the physical and chemical levels respectively through two layers of protection measures, which cooperate with each other to synergistically block corrosive substances, maintain a relatively stable pH value in the internal environment, and protect the carbonization reaction products, thereby ensuring the stability of the digital aggregate strength signal transmission; when the digital aggregate is used for identification management and quality traceability of concrete products, prefabricated components or cast-in-place structures, it can effectively avoid the problem of reduced digital aggregate signal transmission performance caused by external corrosive substances. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0023] The present application provides a corrosion-resistant digital aggregate based on steric barrier, comprising a mineralized aggregate blank and a first protective layer coated on the surface of the mineralized aggregate blank; the aggregate blank comprises a radio frequency unit and a second protective layer coated on the radio frequency unit; the raw materials of the first protective layer include a first protective agent, the first protective agent includes one or more of polyimide, fluorinated ethylene propylene copolymer, and soluble polytetrafluoroethylene; the raw materials of the second protective layer include a carbon mineralized material, a reinforcing agent, and a second protective agent, the second protective agent includes one or more of sodium tetraborate, sodium silicate, and sodium aluminate.

[0024] In the present application, a carbonate mineral is formed by the mineralization reaction of a carbon mineralized material to encapsulate a radio frequency chip to prepare a digital aggregate; wherein, a first protective agent is used on the surface of the digital aggregate, has high density, good hydrophobicity, and strong corrosion resistance, and can physically block the invasion of corrosive substances in the external environment into the digital aggregate, reducing the probability of contact with corrosive substances, and serving as the first barrier of the digital aggregate; a second protective agent is added to the interior of the digital aggregate for use, and the hydroxide generated by its hydrolysis can react with the corrosive substances that break through the first protective agent, serving as the second barrier of the digital aggregate; the first protective agent and the second protective agent protect the digital aggregate successively at the physical and chemical levels, respectively, cooperate with each other, and synergistically block, maintain a relatively stable pH value in the internal environment, and protect the carbonization reaction products, thereby ensuring the stability of the intensity signal transmission of the digital aggregate.

[0025] In the present application, the first protective agent can be made into a solution with strong adhesion, good film-forming performance, strong hydrophobicity, dense structure, and excellent corrosion resistance. After film formation, it can effectively block corrosive substances, protect the digital aggregate at the physical level, and reduce the probability of contact between corrosive substances and digital aggregates; the second protective agent can hydrolyze to form weak acids and hydroxides, and promptly capture corrosive substances that break through the first protective layer and penetrate deep into the digital aggregate, maintaining the relative stability of the pH inside the digital aggregate. The weak acid is weaker than carbonic acid, does not react with the digital aggregate, and has a dielectric constant close to that of the carbon mineralization product, which has little effect on the signal transmission performance of the digital aggregate.

[0026] In some embodiments, the mass ratio of the radio frequency unit, the carbon mineralized material, the first protective agent, the second protective agent, the reinforcing agent, and water is 1:8-64:1-21:2-40:1-11:1-21.

[0027] In some embodiments, the carbon mineralized material includes one or more of tricalcium silicate, gamma-type dicalcium silicate, beta-type dicalcium silicate, monocalcium silicate, tricalcium disilicate, calcium hydroxide, magnesium hydroxide, calcium oxide, and magnesium oxide; and the particle size of the carbon mineralized material is 75-150 μm.

[0028] In some embodiments, the reinforcing agent includes one or more of chitosan, sodium alginate, polyethylene glycol, and polyvinyl alcohol. The reinforcing agent can induce the formation of more carbonate minerals during the mineralization reaction, fill the pores of the digital aggregate, improve the compatibility of the digital aggregate with concrete materials, and increase the compressive strength of the digital aggregate.

[0029] In some embodiments, the RF unit includes an RF chip and an RF antenna connected to the RF chip. Under stimulation from a signal collector, information within the RF chip can be transmitted by the RF antenna and received by the signal collector. The signal collector operates at frequencies ranging from 30-300kHz low frequency, 3-30MHz high frequency, and 433-950MHz ultra-high frequency.

[0030] In a second aspect, the present application provides a method for preparing a corrosion-resistant digital aggregate based on steric barrier, comprising the following steps:

[0031] S1. The carbon mineralized material, the second protective agent, the reinforcing agent and water are mixed to obtain a mixture;

[0032] S2. In the mold, the RF unit is embedded in the mixture and pressed to obtain an aggregate body; the specific embedding process is to fill the mixture into the mold half-height position, and place the RF unit in the center of the mold, and continue to fill the mixture until it is filled;

[0033] S3. Under a carbon dioxide atmosphere, the aggregate body is mineralized to obtain a mineralized aggregate body;

[0034] S4. Apply the first protective agent to the surface of the mineralized aggregate body, and after drying to form a film, obtain a corrosion-resistant digital aggregate based on three-dimensional barrier.

[0035] In some embodiments, the aggregate blank includes regular shapes and / or irregular shapes according to the morphology of the mold, and the regular shapes include but are not limited to cylinders, squares, and strips.

[0036] Preferably, in step S2, the pressing pressure is 10-60 MPa.

[0037] Preferably, in step S3, the partial pressure of carbon dioxide is 0.1-0.3 MPa, the volume concentration of carbon dioxide is 20-99.9%, the mineralization temperature is 5-90° C., and the mineralization time is 12-48 h.

[0038] Preferably, in step S4, the coating thickness is 0.1-0.5 mm, and the film forming time is 1-3 min.

[0039] In a third aspect, the present application provides an application of a corrosion-resistant digital aggregate based on three-dimensional barrier in the field of concrete components and / or cast-in-place structures.

[0040] The corrosion-resistant digital aggregate design and preparation method based on three-dimensional barrier proposed in the present invention has a simple technical principle and obvious effect. The digital aggregate prepared based on this method can be widely used on the surface or interior of concrete products, prefabricated components or cast-in-place structures, and has excellent corrosion resistance.

[0041] The present invention is further described below through specific examples.

[0042] Example 1

[0043] A corrosion-resistant digital aggregate based on three-dimensional barrier comprises a mineralized aggregate blank and a first protective layer coated on the surface of the mineralized aggregate blank; the aggregate blank comprises a radio frequency unit and a second protective layer coated on the radio frequency unit; the raw materials of the first protective layer comprise a first protective agent, which is polyimide; the raw materials of the second protective layer are a mixture of γ-type dicalcium silicate with a particle size of 150 μm, chitosan, and sodium tetraborate; the radio frequency unit comprises a radio frequency chip and a radio frequency antenna connected to the radio frequency chip; the amounts of the radio frequency unit, γ-type dicalcium silicate, polyimide, sodium tetraborate, chitosan, and water are 1 part, 36 parts, 11 parts, 21 parts, 6 parts, and 11 parts, respectively.

[0044] The preparation method of corrosion-resistant digital aggregate based on steric barrier comprises the following steps:

[0045] S1. Chitosan is mixed with water to form a mixture, and γ-type dicalcium silicate and sodium tetraborate are mixed with the mixture to obtain a mixture;

[0046] S2. The mixture is filled into the mold at half height, and the RF unit is placed in the center of the mold, and the mixture is continued to be filled until it is filled, and the aggregate body is prepared by pressing; the pressing pressure is 30MPa, and the above steps are repeated to prepare 6 aggregate bodies;

[0047] S3. The aggregate body was placed in a carbon dioxide atmosphere for mineralization at a pressure of 0.2 MPa, a temperature of 25°C, a relative humidity of 50%, a carbon dioxide volume concentration of 99.9%, and a duration of 24 h to obtain a mineralized aggregate body;

[0048] S4. The polyimide solution is coated on the surface of the mineralized aggregate body with a coating thickness of 0.1 mm. After drying for 2 minutes to form a film, a corrosion-resistant digital aggregate based on steric barrier is obtained.

[0049] Example 2

[0050] A corrosion-resistant digital aggregate based on steric barrier, other contents are the same as those in Example 1, except that the amount of sodium tetraborate used is 28 parts.

[0051] Example 3

[0052] A corrosion-resistant digital aggregate based on steric barrier, other contents are the same as those in Example 1, except that the amount of sodium tetraborate used is 35 parts.

[0053] Example 4

[0054] A corrosion-resistant digital aggregate based on steric barrier, other contents are the same as those in Example 1, except that the coating thickness of the polyimide solution is 0.2 mm.

[0055] Example 5

[0056] A corrosion-resistant digital aggregate based on steric barrier, other contents are the same as those in Example 1, except that the coating thickness of the polyimide solution is 0.4 mm.

[0057] Example 6

[0058] A corrosion-resistant digital aggregate based on steric barrier, other contents are the same as those in Example 1, except that the amount of chitosan used is 8 parts.

[0059] Example 7

[0060] A corrosion-resistant digital aggregate based on steric barrier, other contents are the same as those in Example 1, except that the amount of chitosan used is 10 parts.

[0061] Comparative Example 1

[0062] A corrosion-resistant digital aggregate based on steric barrier, other contents are the same as those of Example 1, except that the first protective agent and the second protective agent are not added.

[0063] Testing and Evaluation

[0064] The corrosion-resistant digital aggregates prepared in each example and comparative example were divided into two groups. One group was directly used for compressive strength testing and signal transmission distance testing in concrete. The other group was pre-soaked in a 0.01 mol / L dilute sulfuric acid solution for 24 hours. After soaking, the residual dilute sulfuric acid on the surface of the aggregate was removed, and the digital aggregates were then tested for compressive strength and signal transmission distance in concrete. The digital aggregates were embedded in the concrete to a depth of 2 cm, and the signal transmission distance was read using a signal collector operating at an ultra-high frequency (UHF) frequency of 433-950 MHz. The compressive strength of the digital aggregates before and after immersion in the corrosive medium and their maximum reading distance in concrete are shown in Tables 1 and 2.

[0065] Table 1 Test results of compressive strength and maximum reading distance before immersion

[0066] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 1 Compressive strength (MPa) 60.1 58.8 56.2 60.4 60.5 66.4 69.9 68.2 Reading distance in concrete (m) 2.4 2.4 2.3 2.5 2.4 2.7 3.1 2.6

[0067] Table 2 Test results of compressive strength and maximum reading distance after immersion

[0068] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example Compressive strength (MPa) 54.6 57.5 54.4 58.2 58.9 62.7 64.3 40.2 Reading distance in concrete (m) 2.0 2.2 2.2 2.3 2.2 2.2 2.5 1.2

[0069] Compared with Comparative Example 1, the compressive strength and signal readout distance of the digital aggregates prepared in Examples 1-7 were not significantly affected by the dilute sulfuric acid solution. This is because the first protective agent, with its high density, physically blocks the intrusion of corrosive media from the external environment into the digital aggregate. Furthermore, the second protective agent, incorporated into the digital aggregate, hydrolyzes to generate hydroxide, which combines with the corrosive media invading the digital aggregate, maintaining the stability of the carbonization reaction products within the digital aggregate and thus ensuring the strength of the digital aggregate and the stability of signal transmission.

[0070] It can be seen from Examples 1-3 that increasing the amount of the second protective agent used slightly reduces the compressive strength of the digital aggregate. This is because the second protective agent has no carbonization activity, and carbonates cannot be generated to fill the pores during the carbonation reaction, which leads to a decrease in the compressive strength of the digital aggregate. Comparing Example 1, Example 4 and Example 5, as the thickness of the first protective agent increases, the protective effect is enhanced, the invading corrosive substances are reduced, the digital aggregate is not corroded, and the compressive strength of the digital aggregate is not greatly affected. Comparing Example 1, Example 6 and Example 7, as the amount of the reinforcing agent increases, the compressive strength of the digital aggregate is improved. This is because the reinforcing agent can induce the production of more carbonate minerals to fill the pores in the carbon mineralization reaction, thereby improving the compressive strength of the digital aggregate.

[0071] This application uses two layers of protection measures to protect digital aggregates at the physical and chemical levels respectively, which cooperate with each other to block corrosive substances, maintain a relatively stable pH value in the internal environment, and protect the carbonization reaction products, thereby ensuring the stability of the digital aggregate strength signal transmission; when digital aggregates are used for identification management and quality traceability of concrete products, prefabricated components or cast-in-place structures, the problem of reduced digital aggregate signal transmission performance caused by external corrosive substances can be effectively avoided.

[0072] The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A corrosion-resistant digital aggregate based on steric barrier, characterized in that: It includes a mineralized aggregate body and a first protective layer coated on the surface of the mineralized aggregate body; the aggregate body includes a radio frequency unit and a second protective layer coated on the radio frequency unit; the raw material of the first protective layer includes a first protective agent, and the first protective agent includes one or more of polyimide, fluorinated ethylene propylene copolymer, and soluble polytetrafluoroethylene; the raw material of the second protective layer includes a carbon mineralized material, a reinforcing agent, and a second protective agent, and the second protective agent includes one or more of sodium tetraborate, sodium silicate, and sodium aluminate.

2. The corrosion-resistant digital aggregate based on steric barrier according to claim 1, characterized in that: The mass ratio of the radio frequency unit, the carbon mineralized material, the first protective agent, the second protective agent, and the reinforcing agent is 1:8-64:1-21:2-40:1-11.

3. The corrosion-resistant digital aggregate based on steric barrier according to claim 1, characterized in that: The carbon mineralized material includes one or more of tricalcium silicate, gamma-type dicalcium silicate, beta-type dicalcium silicate, monocalcium silicate, tricalcium disilicate, calcium hydroxide, magnesium hydroxide, calcium oxide, and magnesium oxide; and the particle size of the carbon mineralized material is 75-150 μm.

4. The corrosion-resistant digital aggregate based on steric barrier according to claim 1, characterized in that: The enhancer includes one or more of chitosan, sodium alginate, polyethylene glycol, and polyvinyl alcohol.

5. The corrosion-resistant digital aggregate based on steric barrier according to claim 1, characterized in that: The radio frequency unit includes a radio frequency chip and a radio frequency antenna connected to the radio frequency chip.

6. A method for preparing a corrosion-resistant digital aggregate based on steric barrier according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. The carbon mineralized material, the second protective agent, the reinforcing agent and water are mixed to obtain a mixture; S2. In a mold, the RF unit is embedded in the mixture and pressed to obtain an aggregate body; S3. Under a carbon dioxide atmosphere, the aggregate body is mineralized to obtain a mineralized aggregate body; S4. Applying the first protective agent to the surface of the mineralized aggregate blank and drying it to form a film, thereby obtaining the corrosion-resistant digital aggregate based on steric barrier.

7. The method for preparing corrosion-resistant digital aggregate based on steric barrier according to claim 6, characterized in that: In step S2, the pressing pressure is 10-60 MPa.

8. The method for preparing corrosion-resistant digital aggregate based on steric barrier according to claim 6, characterized in that: In step S3, the partial pressure of carbon dioxide is 0.1-0.3 MPa, the volume concentration of carbon dioxide is 20-99.9%, the mineralization temperature is 5-90° C., and the mineralization time is 12-48 hours.

9. The method for preparing corrosion-resistant digital aggregate based on steric barrier according to claim 6, characterized in that: In step S4, the coating thickness is 0.1-0.5 mm, and the film forming time is 1-3 minutes.

10. Use of the corrosion-resistant digital aggregate based on steric barrier obtained by the preparation method according to any one of claims 6 to 9 in the field of concrete components and / or cast-in-place structures.