Preparation method of concrete crack self-repairing particles

Abstract

The invention relates to the field of concrete processing, and particularly discloses a preparation method of concrete crack self-repairing particles. Comprising the following steps: S1, activating bacillus pasteurii to obtain a bacterial suspension; s2, placing the adsorption particle modified fiber in a bacterial suspension for adsorption treatment to obtain a load material; and S3, uniformly spraying alkyd resin liquid on the surface of the load material, drying and dispersing to obtain a finished product. When new micro-crack damage is generated in the use process of the concrete, the microorganisms play a self-repairing role to fill cracks in the concrete, so that the strength of the concrete is maintained, the service life of the concrete is prolonged, and the durability of the concrete is improved.

Description

Technical Field

[0001] The present application relates to the field of concrete processing, and more specifically, to a method for preparing concrete crack self-repairing particles. Background Art

[0002] Concrete is the most widely used and largest-volume building material in the field of civil engineering. Its main components are cement, sand and gravel. Although concrete has the advantages of high strength and good durability, it is inevitably damaged by micro cracks inside or on the surface of the concrete due to the influence of factors such as temperature changes, external loads or corrosion during long-term use. The micro cracks inside the concrete will further expand, resulting in reduced durability and bearing capacity of the structure, and ultimately causing damage to the structural components.

[0003] In order to extend the service life of concrete and reduce the generation and spread of internal microcracks, self-repair methods are generally used to repair concrete; concrete self-repair technology refers to the process of using additives such as calcification or microorganisms to produce new materials inside the concrete to fill the damaged parts after the concrete structure is damaged, thereby repairing the cracks and pores produced to ensure the life and durability of the concrete.

[0004] During the self-repair process of microorganisms in concrete, due to the high alkaline environment inside the concrete, limited living space and other issues, directly adding microorganisms into concrete will cause the number of live bacteria to be significantly reduced, affecting the self-repair effect of cracks; and during the initial use of concrete after preparation, no new crack damage is generated inside due to external temperature changes, external loads or corrosion. At this time, microbial self-repair is not required. Microorganisms are only needed to self-repair new cracks when new cracks appear. Otherwise, the expansion and filling generated during the initial microbial self-repair process in the early stage of use will easily increase the internal structural cracks of the concrete, affecting the strength and service life of the concrete.

[0005] Therefore, when new microcracks damage is generated during the use of concrete, how can microorganisms play a self-repairing role, fill the internal cracks of the concrete, maintain the strength of the concrete, and extend the service life and durability of the concrete. Summary of the invention

[0006] In order to enable microorganisms to play a self-repairing role when new microcracks damage is generated in the use of concrete, fill the internal cracks of the concrete, maintain the strength of the concrete, and extend the service life and durability of the concrete, the present application provides a method for preparing concrete crack self-repairing particles.

[0007] The present application provides a method for preparing concrete crack self-repairing particles, which adopts the following technical solution: A method for preparing concrete crack self-repairing particles comprises the following steps: S1, activating Bacillus pasteurianus to obtain a bacterial suspension; S2, placing the adsorption particle modified fiber in a bacterial suspension for adsorption treatment to obtain a loaded material; S3. Evenly spray alkyd resin liquid on the surface of the load material, and obtain the finished product after drying and dispersion.

[0008] By adopting the above technical scheme, after Bacillus pasteurianus is prepared into a bacterial suspension, the bacterial suspension is adsorbed by the adsorption particle modified fiber, and then the alkyd resin liquid is evenly sprayed on the surface. The high viscosity of the alkyd resin liquid can stably bond and coat the surface of the ammonium bicarbonate modified diatomaceous earth particles to form a water-proof film layer, thereby avoiding as much as possible that the moisture in the concrete mixture is absorbed by the adsorption particle modified fiber and affects the amount of hydration water in the mixing water, thereby ensuring the normal hydration reaction of the concrete and forming concrete with higher strength; and avoiding as much as possible that Bacillus pasteurianus does not produce an expansion and filling effect during the concrete preparation process and the initial use process.

[0009] As the concrete is used for a longer time, cracks gradually appear inside the concrete due to tensile stress caused by external environmental factors. Alkyd resin is brittle and easily breaks directly under tensile stress, exposing the Bacillus pasteurianus adsorbed in the adsorption particle modified fiber. The expansion and filling effect of Bacillus pasteurianus is utilized to achieve self-repair of the newly appeared gaps inside the concrete. At the same time, under the heat insulation conditions of alkyd resin and adsorption particle modified fiber, the influence of hydration heat on Bacillus pasteurianus can be blocked as much as possible, thereby protecting the activity of Bacillus pasteurianus. After the concrete has been used for a long time, Bacillus pasteurianus can still exert its expansion and filling effect to fill the new structural gaps generated inside the concrete, thereby ensuring the strength of the concrete and extending its service life and durability.

[0010] Preferably, the adsorbent particle modified fiber is prepared by the following method: Epoxy resin liquid is sprayed on the surface of the carrier fiber at a mass ratio of 1:0.4-0.7, and then ammonium bicarbonate modified diatomaceous earth particles are added. The mass ratio of the carrier fiber to the ammonium bicarbonate modified diatomaceous earth particles is 1:1-2. After mixing evenly, drying and dispersing, the adsorption particle modified fiber is obtained.

[0011] By adopting the above technical scheme, the epoxy resin is bonded to the surface of the carrier fiber, so as to avoid the carrier fiber from absorbing mixing water as much as possible, and to prevent the carrier fiber from contacting with Bacillus pasteurianus, so as to avoid the reproduction and expansion of Bacillus pasteurianus during the hydration process of concrete and affect the density of the internal structure of concrete; when the ammonium bicarbonate-modified diatomaceous earth particles are bonded to the epoxy resin liquid and the surface of the carrier fiber, a structure in which the fiber is inside, the epoxy resin liquid is in the middle, and the diatomaceous earth particles are outside is achieved. The thermal decomposition effect of ammonium bicarbonate is used to break through the blockade of the epoxy resin, so as to achieve the connection between the internal pores of the diatomaceous earth particles and the external environment, and the non-porous parts of the surface of the diatomaceous earth particles are bonded to the fiber surface by the epoxy resin liquid, and the porous parts are exposed to the outside for the adsorption of Bacillus pasteurianus. The diatomaceous earth has a high adsorption effect and can adsorb Bacillus pasteurianus in the bacterial suspension, thereby ensuring the self-repairing effect of Bacillus pasteurianus on cracks in the concrete.

[0012] Preferably, the carrier fiber is composed of soybean protein peptide modified bamboo fiber and pullulan modified polyester fiber in a mass ratio of 1:0.5-1.

[0013] By adopting the above technical scheme, soybean protein peptide modified bamboo fiber and pullulan modified polyester fiber are combined, soybean protein peptide, bamboo fiber and pullulan can provide carbon source and nitrogen source for Bacillus pasteurianus, and can fill cracks when cracks appear in concrete. In addition, the high elasticity and toughness of polyester fiber can buffer tensile stress and reduce the probability of new cracks in concrete due to heavy load.

[0014] Preferably, the soy protein peptide modified bamboo fiber is prepared by treating bamboo fiber filaments with soy protein peptide liquid.

[0015] By adopting the above technical scheme, the adsorption effect of bamboo fiber is utilized to facilitate the adsorption of soybean protein peptide liquid. The soybean protein peptide can be utilized by Bacillus pasteurianus to provide carbon source and nitrogen source substances for Bacillus pasteurianus, thereby ensuring the expansion self-repair effect of Bacillus pasteurianus. In addition, the bamboo fiber can also be gradually decomposed and utilized by microorganisms. Under long-term conditions, Bacillus pasteurianus has a self-repair effect, which can further extend the durability and service life of concrete.

[0016] Preferably, the pullulan-modified polyester fiber is made of polyester fiber and pullulan solution in a mass ratio of 1:0.1-0.25.

[0017] By adopting the above technical scheme, the polyester fiber has good elasticity and toughness. Combined with the elasticity and toughness of the pullulan solution, the fiber has a certain impact resistance, can buffer the stress of cracks, try to avoid the occurrence of cracks inside the concrete, and extend the durability and service life of the concrete.

[0018] Pullulan has high viscosity, which not only makes it easy to bond to the fiber surface, but also improves the adhesion stability of epoxy resin and alkyd resin on the fiber surface. During the use of concrete, it reduces the number of cracks in the concrete caused by the external environment, and even after cracks appear in the concrete, it can have a good self-repairing effect.

[0019] Preferably, the ammonium bicarbonate-modified diatomaceous earth particles are prepared by treating diatomaceous earth with an ammonium bicarbonate solution and a polyethylene glycol solution in sequence, followed by freeze-drying.

[0020] By adopting the above technical scheme, the diatomaceous earth is first loaded with ammonium bicarbonate and then loaded with the polyethylene glycol solution. The adsorption effect of the diatomaceous earth is utilized to facilitate the adsorption of ammonium bicarbonate and polyethylene glycol. By utilizing freeze drying, the internal pores of the diatomaceous earth are ensured and the ammonium bicarbonate is retained. In the process of preparing the adsorption particle modified fiber, the thermal decomposition of ammonium bicarbonate can ensure that the pores of the diatomaceous earth are in contact with the Bacillus pasteurianus in the bacterial suspension, thereby ensuring the loading of the Bacillus pasteurianus. Combined with the bonding effect of the polyethylene glycol in the pores of the diatomaceous earth, the Bacillus pasteurianus can be more stably attached to the internal pores of the diatomaceous earth, and the loading effect is not easily affected by operations such as stirring. While increasing the loading rate of the Bacillus pasteurianus, the cracks generated in the internal structure of the concrete can be repaired for a long time, thereby extending the service life and durability of the concrete.

[0021] Preferably, the epoxy resin liquid is made of epoxy resin, curing agent and calcium chloride in a mass ratio of 1:0.1-0.3:0.2-0.4.

[0022] By adopting the above technical scheme, epoxy resin, curing agent and calcium chloride are matched, and the filling effect of calcium chloride is utilized, and the brittleness of the epoxy resin curing agent after film formation is combined, when subjected to tensile stress in the cracks inside the concrete, the film layer is easily destroyed, so that Bacillus pasteurianus can contact with the nutrients in the carrier fiber, thereby promoting the growth and reproduction of Bacillus pasteurianus, and utilizing its expansion and filling effect to fill the pores when cracks occur in the internal structure of the concrete, thereby ensuring the strength of the concrete and extending the durability and service life of the concrete.

[0023] Preferably, the alkyd resin solution is made of alkyd resin, shellac solution and sodium alginate solution in a mass ratio of 1:0.1-0.2:0.05-0.1.

[0024] By adopting the above technical scheme, alkyd resin, shellac liquid and sodium alginate solution are matched, and the carboxyl groups in the shellac liquid, the carboxyl groups in the sodium alginate and the hydroxyl groups in the alkyd resin are easy to cross-link and bond to form a film layer. When subjected to tensile stress of cracks in the internal structure of concrete, the alkyd resin film is easily destroyed, so that when cracks are generated in the concrete, Bacillus pasteurianus is exposed to fill and seal the cracks, thereby ensuring the strength of the concrete; and the shellac liquid has a good waterproof effect and cooperates with the waterproof effect of the alkyd resin, so that Bacillus pasteurianus is not easy to contact with mixing water, thereby ensuring the strength of the concrete.

[0025] When structural cracks appear inside the concrete due to long-term use, causing the membrane layer to be damaged, the gradually exposed sodium alginate comes into contact with calcium chloride. When water accumulates in the cracks during rainy weather, the calcium chloride easily reacts with the sodium alginate solution to generate calcium alginate, which expands and fills the internal structural cracks of the concrete. By increasing the calcium content, the strength of the concrete is further guaranteed, extending the durability and service life of the concrete.

[0026] Preferably, the adsorption treatment in S2 is specifically: firstly ultrasonic dispersion and then negative pressure treatment.

[0027] By adopting the above technical scheme, ultrasonic dispersion is performed to make the adsorption particle modified fiber contact with the bacterial suspension evenly, and negative pressure treatment is performed to facilitate the bacteria in the bacterial suspension to be adsorbed by the adsorption particle modified fiber, thereby ensuring the self-repairing effect of concrete.

[0028] Preferably, the drying is carried out by air drying at a temperature of 38-45°C.

[0029] By adopting the above technical solution, the drying temperature is limited and the activity of Bacillus pasteurianus is guaranteed.

[0030] In summary, this application has the following beneficial effects: 1. After preparing Bacillus pasteurianus into bacterial suspension, the bacterial suspension is adsorbed by adsorption particle modified fiber, and then alkyd resin liquid is evenly sprayed on the surface to form a water-proof film layer by using the alkyd resin liquid to avoid the moisture in the concrete mixture being absorbed by the adsorption particle modified fiber as much as possible to ensure the strength of the concrete; and prevent Bacillus pasteurianus from producing an expansion and filling effect during the concrete preparation process. When structural cracks are generated in the concrete after a long period of use, Bacillus pasteurianus can still play an expansion and filling effect and fill the internal structural gaps of the concrete, thereby ensuring the strength of the concrete and extending the service life and durability.

[0031] 2. Soy protein peptide liquid, pullulan solution, epoxy resin and alkyd resin are matched, and the amino and carboxyl groups in the soybean protein peptide and the hydroxyl groups in the pullulan solution are used to facilitate cross-linking with the epoxy resin and the alkyd resin, thereby promoting the formation of a surface film layer. On the one hand, it protects Bacillus pasteurianus from affecting the amount of mixing water during the hydration process; on the other hand, it protects Bacillus pasteurianus from affecting the density of the concrete structure due to its self-repairing effect during the hydration process of concrete, thereby ensuring the strength and durability of the concrete; in the process of tensile stress generated by new cracks, the film layer is easy to break and expose Bacillus pasteurianus, and the self-repairing effect of Bacillus pasteurianus is used to fill the new cracks inside the concrete, thereby ensuring that the concrete still has a high strength after long-term use, thereby extending the durability and service life of the concrete.

[0032] 3. When the alkyd resin film and epoxy resin film are damaged during the process of concrete cracking, calcium chloride comes into contact with sodium alginate. If water accumulates in the cracks during rainy weather, calcium chloride will easily react with sodium alginate solution to generate calcium alginate that expands and fills the cracks in the internal structure of the concrete. By increasing the calcium content, the strength of the concrete is further guaranteed, and the durability and service life of the concrete are extended. DETAILED DESCRIPTION

[0033] The present application is further described in detail below with reference to the embodiments.

[0034] Preparation example of loaded fiber The soybean protein peptide in the following raw materials was purchased from Xi'an Anao Biotechnology Co., Ltd., with a molecular weight of 800Da; other raw materials are all commercially available.

[0035] Preparation Example 1: The carrier fiber is prepared by the following method: 1 kg of bamboo fiber filaments were weighed and placed in 10 kg of soybean protein peptide solution, the average length of the bamboo fiber filaments was 0.3 mm, the soybean protein peptide solution was a 10% by mass soybean protein peptide aqueous solution, ultrasonically dispersed at 20 kHz for 10 minutes, and then the bamboo fiber filaments were filtered and separated, and dried to obtain soybean protein peptide modified bamboo fiber; 0.2 kg of pullulan solution is evenly sprayed on the surface of 1 kg of polyester fiber, wherein the pullulan is a pullulan aqueous solution with a mass fraction of 2%, and the average length of the polyester fiber is 0.2 mm. After drying and dispersion, pullulan-modified polyester fiber is obtained; 1 kg of soybean protein peptide-modified bamboo fiber and 0.8 kg of pullulan-modified polyester fiber are evenly mixed to obtain carrier fiber.

[0036] Preparation Example 2: This preparation example differs from Preparation Example 1 in that: 0.1 kg of pullulan solution is evenly sprayed on the surface of 1 kg of polyester fiber, wherein the pullulan is a pullulan aqueous solution with a mass fraction of 2%, and the average length of the polyester fiber is 0.2 mm. After drying and dispersion, pullulan-modified polyester fiber is obtained; 1 kg of soybean protein peptide-modified bamboo fiber and 0.5 kg of pullulan-modified polyester fiber are evenly mixed to obtain carrier fiber.

[0037] Preparation Example 3: This preparation example differs from Preparation Example 1 in that: 0.25 kg of pullulan solution is evenly sprayed on the surface of 1 kg of polyester fiber, wherein the pullulan is a pullulan aqueous solution with a mass fraction of 2%, and the average length of the polyester fiber is 0.2 mm. After drying and dispersion, pullulan-modified polyester fiber is obtained; 1 kg of soybean protein peptide-modified bamboo fiber and 1 kg of pullulan-modified polyester fiber are evenly mixed to obtain carrier fiber.

[0038] Preparation example of adsorbent particle modified fiber The following raw materials are all commercially available.

[0039] Preparation Example 4: Adsorbent particle modified fiber is prepared by the following method: 1 kg of diatomaceous earth is placed in 20 kg of ammonium bicarbonate solution, the ammonium bicarbonate solution is an aqueous solution of ammonium bicarbonate with a mass fraction of 10%, and ultrasonically dispersed at 20 kHz for 30 minutes, the diatomaceous earth is taken out, and then placed in 10 kg of polyethylene glycol solution and continued to disperse and stir for 20 minutes, the polyethylene glycol solution is an aqueous solution of polyethylene glycol with a mass fraction of 5%, the polyethylene glycol is polyethylene glycol 8000, and the average particle size of the diatomaceous earth is 0.3 mm; then the diatomaceous earth is separated by filtration, and freeze-dried at -20°C for 12 hours to obtain diatomaceous earth particles; 1 kg of epoxy resin and 0.3 kg of calcium chloride were mixed and stirred evenly, and then 0.2 kg of curing agent was added and mixed and stirred evenly to obtain epoxy resin liquid. The epoxy resin was E51, the curing agent was triethylenetetramine, and the average particle size of calcium chloride was 80 μm; 0.5 kg of epoxy resin liquid is evenly sprayed on the surface of 1 kg of the carrier fiber prepared in Preparation Example 1, and then 1.5 kg of ammonium bicarbonate-modified diatomaceous earth particles are added at a rate of 100 g / min. During the adding process, the carrier fiber is stirred at a speed of 200 r / min. After mixing evenly, it is dried at 90 degrees Celsius until the ammonium bicarbonate is completely decomposed. Finally, it is dispersed to obtain adsorption particle modified fiber. The average particle size of the adsorption particle modified fiber is 1 mm.

[0040] Preparation Example 5: This preparation example differs from Preparation Example 4 in that: 1 kg of epoxy resin and 0.2 kg of calcium chloride were mixed and stirred evenly, and then 0.1 kg of curing agent was added and mixed and stirred evenly to obtain epoxy resin liquid. The epoxy resin was E51, the curing agent was triethylenetetramine, and the average particle size of calcium chloride was 80 μm; 0.4 kg of epoxy resin liquid was evenly sprayed on the surface of 1 kg of the carrier fiber prepared in Preparation Example 2, and then 1 kg of ammonium bicarbonate-modified diatomaceous earth particles were added at a rate of 100 g / min. During the adding process, the carrier fiber was stirred at a speed of 200 r / min. After uniform mixing, it was dried and dispersed to obtain adsorption particle-modified fiber.

[0041] Preparation Example 6: This preparation example differs from Preparation Example 4 in that: 1 kg of epoxy resin and 0.4 kg of calcium chloride were mixed and stirred evenly, and then 0.3 kg of curing agent was added and mixed and stirred evenly to obtain epoxy resin liquid. The epoxy resin was E51, the curing agent was triethylenetetramine, and the average particle size of calcium chloride was 80 μm; 0.7 kg of epoxy resin liquid was evenly sprayed on the surface of 1 kg of the carrier fiber prepared in Preparation Example 3, and then 2 kg of ammonium bicarbonate-modified diatomaceous earth particles were added at a rate of 100 g / min. During the adding process, the carrier fiber was stirred at a speed of 200 r / min. After uniform mixing, it was dried and dispersed to obtain adsorption particle-modified fiber.

[0042] Preparation example of alkyd resin solution The alkyd resin in the following raw materials was purchased from Hanpin Paint (Shandong) Co., Ltd., with an oil length of 55; other raw materials are all commercially available.

[0043] Preparation Example 7: Alkyd resin liquid is prepared by the following method: The shellac is placed in ethanol and stirred until the shellac is completely dissolved, and the mass fraction of ethanol is 99%, thereby obtaining a shellac solution with a mass fraction of 1%; sodium alginate is placed in water and stirred until the sodium alginate is completely dissolved, thereby obtaining a sodium alginate solution with a mass fraction of 1%; 0.2 kg of shellac solution was added to 1 kg of alkyd resin, and then 0.1 kg of sodium alginate solution was added, and the mixture was mixed evenly to obtain an alkyd resin solution.

[0044] Preparation Example 8: This preparation example differs from Preparation Example 7 in that: 0.1 g of shellac solution was added to 1 kg of alkyd resin, and then 0.05 kg of sodium alginate solution was added, and the mixture was mixed evenly to obtain an alkyd resin solution. Example

[0045] The Bacillus pasteurianus in the following raw materials was purchased from the National Culture Collection Center (Sporosarcina pasteurii ATCC11859); other raw materials and equipment were commercially available.

[0046] Example 1: A method for preparing concrete crack self-repairing particles: S1. After activating Bacillus pasteurianum by streaking on a plate, 10 mL of normal saline is added to 1 g of Bacillus pasteurianum to prepare a bacterial suspension; the Bacillus pasteurianum is lyophilized powder of Bacillus pasteurianum; S2. The adsorbent particle modified fiber prepared in Preparation Example 4 was placed in a bacterial suspension at a mass ratio of 1:50, and ultrasonically dispersed for 10 min at 20 kHz, and then adsorbed for 30 min at a negative pressure of -0.05 MPa, and air-dried at 40° C. after decompression to obtain a loaded material; S3. Spray 0.5 kg of the alkyd resin liquid prepared in Preparation Example 7 evenly on the surface of 1 kg of the load material, then air-dry at 40° C. and disperse to obtain a finished product with an average particle size of 1.5 mm.

[0047] Embodiment 2: This embodiment differs from Embodiment 1 in that: S1. After activating Bacillus pasteurianum by streaking on a plate, 10 mL of normal saline was added to 1 g of Bacillus pasteurianum to prepare a bacterial suspension; S2. The adsorbent particle modified fiber prepared in Preparation Example 5 was placed in a bacterial suspension at a mass ratio of 1:50, and ultrasonically dispersed at 20kHz for 10 minutes, and then adsorbed at a vacuum degree of -0.05MPa for 30 minutes, and air-dried at 38°C after decompression to obtain a loaded material; S3. Spray 0.5 kg of the alkyd resin solution prepared in Preparation Example 8 evenly on the surface of 1 kg of the loading material, then air-dry at 38° C. and disperse to obtain a finished product.

[0048] Embodiment 3: This embodiment differs from Embodiment 1 in that: S1. After activating Bacillus pasteurianum by streaking on a plate, 10 mL of normal saline was added to 1 g of Bacillus pasteurianum to prepare a bacterial suspension; S2. The adsorbent particle modified fiber prepared in Preparation Example 6 was placed in a bacterial suspension at a mass ratio of 1:50, and ultrasonically dispersed at 20kHz for 10 minutes, and then adsorbed at a vacuum degree of -0.05MPa for 30 minutes, and air-dried at 45°C after decompression to obtain a loaded material; S3. Spray 0.5 kg of the alkyd resin solution prepared in Preparation Example 7 evenly on the surface of 1 kg of the loading material, then air-dry at 45° C. and disperse to obtain a finished product.

[0049] Embodiment 4: This embodiment differs from Embodiment 1 in that: No epoxy resin liquid was added during the preparation of the adsorbent particle modified fiber.

[0050] Embodiment 5: This embodiment differs from Embodiment 1 in that: In the adsorbed particle modified fibers, the soybean protein peptide modified bamboo fibers were replaced by bamboo fibers of equal mass in the carrier fibers, and the pullulan modified polyester fibers were replaced by polyester fibers of equal mass in the carrier fibers.

[0051] Embodiment 6: This embodiment differs from Embodiment 1 in that: In the adsorbed particle modified fibers, pullulan-modified polyester fibers were not added to the carrier fibers.

[0052] Embodiment 7: This embodiment differs from Embodiment 1 in that: In the adsorption particle modified fiber, the ammonium bicarbonate modified diatomaceous earth particles are replaced with diatomaceous earth of equal mass.

[0053] Embodiment 8: This embodiment differs from Embodiment 1 in that: The ammonium bicarbonate-modified diatomaceous earth particles in the adsorbent particle-modified fibers were not treated with a polyethylene glycol solution during the preparation process.

[0054] Embodiment 9: This embodiment differs from Embodiment 1 in that: In the adsorbent particle modified fiber, no calcium chloride was added to the epoxy resin solution.

[0055] Embodiment 10: This embodiment differs from Embodiment 1 in that: No shellac solution and sodium alginate solution were added to the alkyd resin solution.

[0056] Comparative Example Comparative Example 1: The difference between this comparative example and Example 1 is that: S2. The adsorbent particle modified fiber prepared in Preparation Example 4 is placed in a bacterial suspension at a mass ratio of 1:50, ultrasonically dispersed at 20 kHz for 10 minutes, then adsorbed at a negative pressure of -0.05 MPa for 30 minutes, and air-dried at 40°C after depressurization to obtain a finished product.

[0057] Comparative Example 2: The difference between this comparative example and Example 1 is that: The adsorbent particle modified fiber is replaced by an equal mass of diatomaceous earth in the raw material.

[0058] Application Examples Application example 1: a self-repairing concrete; Weigh 200kg of cement, 20kg of mineral powder, 40kg of fly ash, 650kg of river sand, 800kg of crushed stone, 4.5kg of water reducer, 148kg of water, and 3.5kg of basalt fiber, mix them evenly, then add 70kg of self-repairing particles and mix them evenly to obtain concrete mixture, which is poured and cured to obtain concrete; the cement is ordinary Portland cement with a strength of 42.5; the particle size of the crushed stone is 5-25mm continuous grading, and the mud content is less than 1%; the medium sand is the medium sand in zone II, and the apparent density is 2660kg / m 3 , fineness modulus is 2.5, mud content is <1.0%; fly ash is F class II fly ash, fly ash fineness (45μm square hole sieve residue) is 8%, ignition loss is <4.5%, water requirement ratio is <96%, water content is <0.2%; mineral powder is S95 grade slag powder, density is 2.8g / cm 3 , with a specific surface area of ​​420m 2 / kg, activity index (7d) is 82%, activity index (28d) is 94%, fluidity ratio is 96%, water content is 0.2%; the water reducer adopts AN4000 polycarboxylic acid high-performance water reducer produced in Beijing, with a density of 1.049g / cm 3 , pH value is 5.8, water reduction rate is 32%, air content is 4.0%, solid content is 22.16%, collapse changes by 10 mm over time in 1 hour; the average length of basalt fiber is 3 mm; the self-healing particles are selected from the self-healing particles prepared in Example 1.

[0059] The difference between Application Example 2-10 and Application Example 1 is that the self-repairing particles correspond to the self-repairing particles of Examples 2-10 respectively.

[0060] Comparative Application Examples Comparative Application Example 1: The difference between this comparative application example and application example 1 is: The self-repairing particles are the self-repairing particles prepared in Comparative Example 1.

[0061] Comparative Application Example 2: The difference between this comparative application example and application example 1 is: The self-repairing particles are the self-repairing particles prepared in Comparative Example 2.

[0062] Comparative Application Example 3: The difference between this comparative application example and application example 1 is: No self-healing particles are added to the concrete raw materials.

[0063] Performance testing 1. Strength detection Concrete samples were prepared using the preparation methods of Application Examples 1-10 and Comparative Application Examples 1-3 respectively; Refer to GB / T50081-2016 to test the 28d compressive strength of concrete and record the data; Refer to GB / T50081-2016 to test the crack resistance of concrete, and calculate the total crack area per unit area 28 days after concrete pouring.

[0064] 2. Durability test Concrete samples were prepared using the preparation methods of Application Examples 1-10 and Comparative Application Examples 1-3 respectively; Sunbathe at 35℃ for 8h every day, then at 20kg / m 2 The steel was treated under a load of 16 hours. After 180 days, the total cracking area and compressive strength data were tested again with reference to GB / T50081-2016.

[0065] In the above test experiments, except for the different samples of Application Examples 1-10 and Comparative Application Examples 1-3, the other test conditions are the same.

[0066] Table 1 Performance test table It can be seen from Application Examples 1-3 and Table 1 that the self-repairing particles prepared in the present application have a good repair effect. In the initial use of concrete, the concrete is guaranteed to have a high strength. After long-term use under heavy load and high temperature conditions, it still has good strength and the crack area changes little, indicating that the self-repairing particles fill the cracks in the concrete and ensure the service life and durability of the concrete.

[0067] Combining Application Example 1 and Application Examples 4-10 and Table 1, it can be seen that no epoxy resin liquid was added during the preparation of the adsorbent particle modified fiber in Application Example 4. Compared with Application Example 1, the strength of the concrete prepared in Application Example 4 is lower than that in Application Example 1, and the crack area is larger than that in Application Example 1. After long-term heavy load and high temperature treatment, the increase in the crack area is greater than that in Application Example 1; this indicates that the treatment with epoxy resin liquid can protect the carbon source and nitrogen source substances in the loading fiber from being easily contacted with Bacillus pasteurianus in the process where no new cracks appear in the concrete, thereby minimizing the occurrence of cracks in the concrete due to the expansion and filling of Bacillus pasteurianus in the initial use period after the concrete pouring is completed. When cracks appear in the concrete due to factors such as heavy load, the expansion and filling effect of Bacillus pasteurianus is used to fill the cracks, thereby ensuring that the strength of the concrete after long-term use is still close to the initial strength, thereby extending the service life of the concrete.

[0068] In the modified fibers of adsorbed particles in Application Example 5, the soybean protein peptide-modified bamboo fiber in the carrier fiber is replaced by an equal mass of bamboo fiber, and the pullulan-modified polyester fiber is replaced by an equal mass of polyester fiber. Compared with Application Example 1, the strength loss value and crack area value of the concrete prepared in Application Example 5 are greater than those in Application Example 1 after long-term use under high load, which indicates that soybean protein peptide and pullulan can provide growth for Bacillus pasteurianus, expand and fill in the cracks in the concrete, and ensure the strength and service life of the concrete.

[0069] In the adsorbent particle modified fiber of Application Example 6, pullulan-modified polyester fiber was not added to the carrier fiber. Compared with Application Example 1, the strength loss value and crack area value of the concrete prepared in Application Example 6 were greater than those in Application Example 1 after long-term use under high load. This shows that pullulan-modified polyester fiber can not only use its elastic toughness to buffer heavy-load tensile stress and prevent the formation of cracks in concrete during long-term use, but also meet the needs of Bacillus pasteurianus, seal the cracks through the expansion filling effect of microorganisms, and ensure the strength and durability of the concrete.

[0070] In Application Example 7, diatomaceous earth particles modified with ammonium bicarbonate were replaced with diatomaceous earth of equal mass in the adsorbent particle-modified fiber. Compared with Application Example 1, the concrete prepared in Application Example 7 had greater strength loss and cracking area values ​​than those in Application Example 1 after long-term use under high load. This indicates that the diatomaceous earth particles modified with ammonium bicarbonate have a higher porosity and can adsorb more Bacillus pasteurianus, thereby ensuring the filling and sealing effect of Bacillus pasteurianus on concrete cracks, thereby ensuring the strength and service life of the concrete.

[0071] In Application Example 8, the ammonium bicarbonate-modified diatomaceous earth particles in the adsorbent particle-modified fiber were not treated with polyethylene glycol solution during the preparation process. Compared with Application Example 1, the strength loss value and cracking area value of the concrete prepared in Application Example 8 were greater than those in Application Example 1 after long-term use under high load, which indicated that the polyethylene glycol solution was convenient for loading Bacillus pasteurianum and increasing the loading rate of Bacillus pasteurianum in the pores of diatomaceous earth, thereby ensuring the self-repairing effect of Bacillus pasteurianum on concrete.

[0072] In the adsorbent particle modified fiber of Application Example 9, calcium chloride was not added to the epoxy resin liquid. Compared with Application Example 1, the strength loss value and crack area value of the concrete prepared in Application Example 9 were greater than those in Application Example 1 after long-term use under high load. This shows that the addition of calcium chloride can not only cooperate with the sodium alginate solution to fill the cracks in the concrete caused by long-term heavy load, but also the cross-linked structure can ensure the strength of the concrete, so that the concrete still has high strength and good durability after long-term use.

[0073] In Application Example 10, no shellac solution and sodium alginate solution were added to the alkyd resin liquid. Compared with Application Example 1, the concrete prepared in Application Example 10 had greater strength loss and crack area values ​​than those in Application Example 1 after long-term use under high load. This indicates that shellac solution and sodium alginate can improve the bonding effect between the adsorbed particle-modified fiber and the concrete cementitious material, improve the strength and density of the concrete, and after cracks appear in the concrete after long-term use, shellac and sodium alginate can facilitate the rupture of the alkyd resin film, allowing Bacillus pasteurianus to contact nutrients such as soybean protein peptides and pullulan, and utilize the expansion and filling effect of microorganisms to fill the cracks, thereby ensuring the strength of the concrete and extending the service life of the concrete.

[0074] Combining Application Example 1 and Comparative Application Examples 1-3 and Table 1, it can be seen that no alkyd resin liquid was added to the preparation of the self-repairing particles in Comparative Application Example 1. Compared with Application Example 1, the strength of Comparative Application Example 1 is lower than that of Application Example 1, and the cracking area is larger than that of Application Example 1. After long-term use under high load, the strength loss value and the cracking area value are greater than those of Application Example 1; this indicates that the addition of the alkyd resin liquid makes it difficult for Bacillus pasteurianus to contact with the mixing water in the concrete, thereby ensuring the strength of the concrete, and is not easily affected by the hydration reaction. The activity of Bacillus pasteurianus is ensured, thereby ensuring that Bacillus pasteurianus fills cracks in the concrete during use, thereby ensuring the service life and durability of the concrete.

[0075] Comparative Application Example 2 self-repairing particles are used to prepare diatomaceous earth to replace the modified fibers of the adsorption particles. Compared with Application Example 1, the strength of Comparative Application Example 2 is lower than that of Application Example 1, and the crack area is larger than that of Application Example 1. After long-term use under high load, the strength loss value and the crack area value are greater than those of Application Example 1. This shows that although ordinary diatomaceous earth can adsorb Bacillus pasteurianus, Bacillus pasteurianus cannot come into contact with nutrients, which affects the filling effect of the cracks.

[0076] In Comparative Application Example 3, no self-repairing particles were added to the concrete. Compared with Application Example 1, the strength of Comparative Application Example 3 was lower than that of Application Example 1, and the cracking area was larger than that of Application Example 1. After long-term use under high load, the strength loss value and the cracking area value were greater than those of Application Example 1. This shows that the self-repairing particles have a good filling and self-repairing effect. When cracks appear in the concrete after long-term use, they can use their own expansion filling effect to fill the cracks, thereby ensuring the strength of the concrete and extending the service life and durability of the concrete.

[0077] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing concrete crack self-repairing particles, characterized in that: The steps include: S1, activating Bacillus pasteurianus to obtain a bacterial suspension; S2, placing the adsorption particle modified fiber in a bacterial suspension for adsorption treatment to obtain a loaded material; S3. Evenly spray alkyd resin liquid on the surface of the load material, and obtain the finished product after drying and dispersion.

2. The method for preparing a concrete crack self-repairing particle according to claim 1, characterized in that: The adsorbent particle modified fiber is prepared by the following method: Epoxy resin liquid is sprayed on the surface of the carrier fiber at a mass ratio of 1:0.4-0.7, and then ammonium bicarbonate modified diatomaceous earth particles are added. The mass ratio of the carrier fiber to the ammonium bicarbonate modified diatomaceous earth particles is 1:1-2. After mixing evenly, drying and dispersing, the adsorption particle modified fiber is obtained.

3. The method for preparing a concrete crack self-repairing particle according to claim 2, characterized in that: The carrier fiber is composed of soybean protein peptide modified bamboo fiber and pullulan modified polyester fiber in a mass ratio of 1:0.5-1.

4. The method for preparing concrete crack self-repairing particles according to claim 3, characterized in that: The soybean protein peptide modified bamboo fiber is prepared by treating bamboo fiber filaments with soybean protein peptide liquid.

5. The method for preparing concrete crack self-repairing particles according to claim 3, characterized in that: The pullulan-modified polyester fiber is made of polyester fiber and pullulan solution in a mass ratio of 1:0.1-0.

25.

6. The method for preparing concrete crack self-repairing particles according to claim 2, characterized in that: The ammonium bicarbonate modified diatomaceous earth particles are prepared by sequentially treating diatomaceous earth with an ammonium bicarbonate solution and a polyethylene glycol solution, and then freeze-drying the diatomaceous earth.

7. The method for preparing concrete crack self-repairing particles according to claim 2, characterized in that: The epoxy resin liquid is made of epoxy resin, curing agent and calcium chloride in a mass ratio of 1:0.1-0.3:0.2-0.

4.

8. The method for preparing concrete crack self-repairing particles according to claim 1, characterized in that: The alkyd resin solution is prepared from alkyd resin, shellac solution and sodium alginate solution in a mass ratio of 1:0.1-0.2:0.05-0.

1.

9. The method for preparing concrete crack self-repairing particles according to claim 1, characterized in that: The adsorption treatment in S2 is specifically: firstly ultrasonic dispersion and then negative pressure treatment.

10. The method for preparing concrete crack self-repairing particles according to claim 1, characterized in that: The S3 drying is performed by air drying at a temperature of 38-45°C.

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