A self-repairing high-performance concrete

Abstract

The application discloses a self-repairing high-performance concrete, which comprises the following components in parts by mass: 100 parts of cement, 120-200 parts of fine aggregate, 300-500 parts of coarse aggregate, 20-80 parts of water, 4-6 parts of aluminum trichloride hexahydrate, 15-25 parts of fly ash and 8-12 parts of silica fume; the application has the advantages of self-repairing, anti-cracking and anti-permeation.

Description

Technical Field

[0001] The invention relates to self-repairing high-performance concrete. Background Art

[0002] Roads and bridges are the lifeblood of modern society, and their health directly impacts people's quality of life and economic development. However, over time, these infrastructure structures often develop cracks, voids, and other forms of damage due to various factors, such as traffic loads, environmental corrosion, and material aging. Traditional repair methods are often time-consuming and costly, and do not necessarily guarantee long-term effectiveness. In recent years, self-healing concrete technology has attracted widespread attention as a new and promising solution.

[0003] The core idea of ​​self-repair technology is to use specific materials and technologies to enable concrete to self-repair after being damaged, thereby extending its service life. Summary of the Invention

[0004] The purpose of the present invention is to provide a self-repairing high-performance concrete with the advantages of self-repairing, crack prevention and anti-seepage.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A self-repairing high-performance concrete comprises the following components, calculated by mass: 100 parts of cement, 120-200 parts of fine aggregate, 300-500 parts of coarse aggregate, 20-80 parts of water, 4-6 parts of aluminum chloride hexahydrate, 15-25 parts of fly ash and 8-12 parts of silica fume.

[0007] By adopting the above technical solution, cement, fly ash and silica fume are used to generate crystals to fill and seal cracks and improve durability. Aluminum chloride hexahydrate forms calcium hydroxide with calcium ions in a water environment and diffuses into the accumulated water in the pores and cracks of concrete to perform secondary repair and prevent cracking and seepage.

[0008] Furthermore, it also contains 2 to 3 parts of citric acid and 1 to 2 parts of sodium gluconate.

[0009] By adopting the above technical solution, the cement hydration reaction is delayed, making the reaction milder and forming a more stable concrete structure. The formed crystals are gradually released, further enhancing the repair effect.

[0010] Furthermore, it also contains 0.4 to 0.6 parts of nano silicon dioxide.

[0011] The above technical solution is used to react with water to form a colloid, which diffuses into the accumulated water in the pores and cracks of the concrete to carry out repairs.

[0012] Furthermore, mineralizing microorganisms are also included.

[0013] Furthermore, the mineralizing microorganism is selected from Bacillus.

[0014] Using the above technical solution, the study found that some microorganisms have the function of inducing calcium carbonate deposition. When concrete mixed with mineralizing microorganisms cracks, a large amount of calcium carbonate precipitation will form in the cracks, which provides the possibility of achieving self-repair of concrete cracks.

[0015] Furthermore, the mineralized microorganism is coated with a coating layer, and the coating layer contains epoxy resin and polyacrylamide in a mass ratio of 2 to 4:1.

[0016] Furthermore, the coating layer is coated on the outside of the mineralized microorganism by the following method:

[0017] Epoxy resin, polyacrylamide and water are mixed evenly in a mass ratio of 2-4:1:1-2 to prepare a coating slurry, and the coating slurry is evenly sprayed on the immobilized mineralized microorganisms by spray drying. After coating, the coating is dried for later use.

[0018] The above technical solution is adopted to prevent the loss of microorganisms in the carrier and reduce the impact of the external environment on the activity of microorganisms.

[0019] The technical effects of the present invention are mainly reflected in the following aspects:

[0020] Cement and mineral dopants are used to generate crystals, fill and seal cracks, improve crack resistance and impermeability, increase durability, and have a self-repairing effect;

[0021] Adding additives can delay the cement hydration reaction and react with water to form a colloid, making the reaction milder and forming a more stable concrete structure. The formed crystals are gradually released for repair;

[0022] The self-repair of concrete cracks can be achieved by utilizing the ability of microorganisms to induce calcium carbonate deposition. DETAILED DESCRIPTION

[0023] Example 1: A self-repairing high-performance concrete is prepared by the following method:

[0024] The formulated amount of cement, fine aggregate, coarse aggregate, fly ash and silica fume are placed in a concrete mixer and mixed evenly. Then, water and other additives (aluminum chloride hexahydrate in Example 1) are added to the mixer, mixed and formed, and then the concrete product is obtained by demolding and curing.

[0025] The formula information is: calculated by mass, it includes the following components: 100 parts of cement, 120-200 parts of fine aggregate, 300-500 parts of coarse aggregate, 20-80 parts of water, 4-6 parts of aluminum chloride hexahydrate, 15-25 parts of fly ash and 8-12 parts of silica fume.

[0026] The recipe information of Example 1 is shown in Table 1.

[0027] Table 1 Formulation information of Example 1A / 1B / 1C (unit: mass parts)

[0028]

[0029]

[0030] Example 2: A self-repairing high-performance concrete is prepared by the following method:

[0031] Put the formulated amount of cement, fine aggregate, coarse aggregate, fly ash and silica fume into a concrete mixer and mix them evenly. Then add water, aluminum chloride hexahydrate, citric acid and sodium gluconate into the mixer, mix and shape them, remove the mold and perform curing to obtain a concrete product.

[0032] The formula information is: calculated by mass, it includes the following components: 100 parts of cement, 150 parts of fine aggregate, 400 parts of coarse aggregate, 50 parts of water, 5 parts of aluminum chloride hexahydrate, 2.5 parts of citric acid, 1.5 parts of sodium gluconate, 20 parts of fly ash and 10 parts of silica fume.

[0033] Example 3: A self-repairing high-performance concrete is prepared by the following method:

[0034] Put the formulated amount of cement, fine aggregate, coarse aggregate, fly ash and silica fume into a concrete mixer and mix them evenly; then add water, aluminum chloride hexahydrate, citric acid, sodium gluconate and nano-silicon dioxide into the mixer, mix and shape, remove the mold and perform curing to obtain a concrete product.

[0035] The formula information is: calculated by mass, it includes the following components: 100 parts of cement, 150 parts of fine aggregate, 400 parts of coarse aggregate, 50 parts of water, 5 parts of aluminum chloride hexahydrate, 2.5 parts of citric acid, 1.5 parts of sodium gluconate, 0.5 parts of nano-silicon dioxide, 20 parts of fly ash and 10 parts of silica fume.

[0036] Example 4-1: Preparation of Bacillus sp. according to CN117800686A

[0037] 10 μl of Bacillus pseudofirmus was placed in 1 culture medium and cultured at 35°C for 24 hours to obtain a bacterial solution containing Bacillus. The solution was centrifuged at 6000 rpm for 15 minutes at 5°C to remove the upper nutrient solution and water to obtain a concentrated bacterial solution. The bacterial concentration in the concentrated bacterial solution was 10 8 ~10 9 cfu / ml; the culture medium comprises: 5.0 g of soybean protein, 6.0 g of yeast extract, 10 g of glucose, 1.0 g of K2HPO4, 0.2 g of MgSO4·7H2O, 5.0 g of NaCl, 10.0 g of Na2CO3, and 1.0 L of distilled water.

[0038] Furthermore, mineralizing microorganisms are also included.

[0039] Example 4-2: Post-treatment of Bacillus

[0040] 100 ml of the concentrated bacterial solution prepared in Example 4-1 was mixed with 10 g of expanded pearlite powder and stirred for 12 hours, and dried to obtain a microbial adsorption capacity of 1×10 10 cells / L of immobilized mineralizing microorganisms.

[0041] Epoxy resin, polyacrylamide and water are mixed evenly in a mass ratio of 3:1:2 to prepare a coating slurry. The coating slurry is evenly sprayed on the outside of the immobilized mineralized microorganisms by spray drying. After the coating is completed, it is dried for use.

[0042] Example 4-3: A self-repairing high-performance concrete is prepared by the following method:

[0043] Put the formulated amount of cement, fine aggregate, coarse aggregate, fly ash and silica fume into a concrete mixer and mix them evenly; then add water, aluminum chloride hexahydrate, citric acid, sodium gluconate, nano-silicon dioxide and immobilized mineralized microorganisms into the mixer, mix and shape, remove the formwork and perform curing to obtain a concrete product.

[0044] The formula information is: calculated by mass, it includes the following components: 100 parts of cement, 150 parts of fine aggregate, 400 parts of coarse aggregate, 50 parts of water, 5 parts of aluminum chloride hexahydrate, 2.5 parts of citric acid, 1.5 parts of sodium gluconate, 0.5 parts of nano-silicon dioxide, 2 parts of immobilized mineralized microorganisms, 20 parts of fly ash and 10 parts of silica fume.

[0045] Performance Testing

[0046] Refer to the standard "GB / T50082-2009 Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete" to conduct impermeability grade and 28d autogenous shrinkage rate tests (non-contact method).

[0047] Table 2

[0048] Permeation resistance rating <![CDATA[28d自收缩率 / 10 -4 ]]> Example 1A P8 8.9 Example 1B P8 8.2 Example 1C P8 8.3 Example 2 P10 6.9 Example 3 P10 6.0 Example 4-3 P12 3.2

[0049] From Table 2, compared with the prior art, the internal shrinkage of the embodiment is significantly reduced and the anti-permeation grade is improved, and the synergistic effect of the components of the application plays a good role.

[0050] Of course, the above is only a typical example of the present application, in addition to which the present application can have other various specific embodiments, and any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of the present application.

Claims

1. A self-repairing high performance concrete, characterized by: The composition includes the following components by weight: 100 parts of cement, 150 parts of fine aggregate, 400 parts of coarse aggregate, 50 parts of water, 5 parts of aluminum chloride hexahydrate, 2.5 parts of citric acid, 1.5 parts of sodium gluconate, 0.5 parts of nano-silicon dioxide, 2 parts of immobilized mineralized microorganisms, 20 parts of fly ash and 10 parts of silica fume; The self-repairing high-performance concrete is prepared by the following method: cement, fine aggregate, coarse aggregate, fly ash and silica fume in a formulated amount are placed in a concrete mixer and stirred evenly; then water, aluminum chloride hexahydrate, citric acid, sodium gluconate, nano-silicon dioxide and immobilized mineralized microorganisms are added to the mixer, mixed and formed, and then the concrete product is obtained by removing the formwork and curing.

2. The self-repairing high performance concrete according to claim 1, characterized in that: The mineralizing microorganism is selected from Bacillus.

3. The self-repairing high performance concrete according to claim 2, characterized in that: The mineralized microorganism is coated with a coating layer, which contains epoxy resin and polyacrylamide in a mass ratio of 2 to 4:

1.

4. The self-repairing high performance concrete according to claim 3, characterized in that: The coating layer is coated on the outside of the mineralized microorganism by the following method: Epoxy resin, polyacrylamide and water are mixed evenly in a mass ratio of 2-4:1:1-2 to prepare a coating slurry, and the coating slurry is evenly sprayed on the outside of the immobilized mineralized microorganisms by spray drying. After the coating is completed, it is dried for use.

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