Double-repairing-material composite system for self-repairing of internal and external cracks of concrete as well as preparation method and application of double-repairing-material composite system

Abstract

The invention provides a double-repairing-material composite system for self-repairing internal and external cracks of concrete, which comprises an internally doped composite dry powder repairing agent and an externally coated intelligent repairing liquid, the internal doping type composite dry powder repairing agent comprises high-activity modified silicate, silica fume, a composite catalyst, a calcium sulphoaluminate expanding agent, a magnesium oxide expanding agent, epoxy resin microcapsules, surface modified polypropylene fibers, a microbial carrier, a polycarboxylate superplasticizer, a dispersing agent and filler. The external coating type intelligent repairing liquid comprises an alkyl alkoxy silane mixture, a waterborne epoxy-acrylic acid hybrid emulsion, a latent curing agent, superfine core powder, nano silicon dioxide dispersion liquid, nano calcium carbonate, colored active mineral powder, a wetting agent, a defoaming agent, a flatting agent, a mildew preventive and water. Related preparation methods and uses are also provided. The double-repairing-material composite system is easy and convenient to use, can achieve multiple triggering and synergistic effect, can repair internal and external cracks at the same time, and is good in repairing effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to the technical field of concrete crack repair materials, and specifically relates to a double-repair material composite system for internal and external concrete crack self-repairing and a preparation method and application thereof. BACKGROUND

[0002] Building materials are various materials applied in building engineering. Building materials are various and can be roughly divided into structural materials, decorative materials and some special materials. Structural materials include wood, bamboo, stone, cement, concrete, metal, bricks, ceramics, glass, engineering plastics, composite materials, etc. Decorative materials include various paints, plating, veneer, various ceramic tiles, glass with special effects, etc. Special materials are used for waterproofing, moisture-proofing, corrosion-proofing, fire-proofing, flame-retardant, sound-proofing, heat-proofing, thermal insulation, sealing, etc.

[0003] Among them, concrete is widely used in modern buildings due to its excellent compressive strength and durability. However, its inherent brittleness leads to the easy generation of micro-cracks under tension and shrinkage. These micro-cracks provide a channel for the invasion of harmful substances such as water, chloride ions and carbon dioxide, accelerating the corrosion of steel bars and the deterioration of concrete, and seriously threatening the safety and durability of the structure.

[0004] In order to repair concrete cracks, there are currently some self-healing technologies, such as cement-based penetrating crystalline type: slow effect, dependent on sufficient water, ineffective for dry cracks; microcapsule technology: capsules are easily damaged during mixing and pouring, one-time repair, unable to repeat healing, high cost; microbial mineralization technology: the survival rate of bacteria is difficult to guarantee, the repair environment is harsh, and the effect is unstable; external waterproof coating: only can seal the surface, cannot repair internal cracks, and has poor compatibility with the concrete body, easy to age and peel off.

[0005] The existing technologies generally have the problems of single repair mechanism, harsh repair conditions, limited repair effect, and inability to repair internal and external cracks. SUMMARY

[0006] In order to overcome the above-mentioned shortcomings of the prior art, one object of the present application is to provide a double-repair material composite system for internal and external concrete crack self-repairing, which is simple to use, can realize multiple triggers, synergistic effect, internal and external crack repair, has good repair effect, and is suitable for large-scale popularization and application.

[0007] Another object of the present application is to provide a preparation method of the double-repair material composite system for internal and external crack self-repairing of concrete, which is simple to prepare and easy to use, can realize multiple triggering, synergistic effect, internal and external crack repair, has good repair effect, and is suitable for large-scale popularization and application.

[0008] Another object of the present application is to provide an application of the double-repair material composite system for internal and external crack self-repairing of concrete, which can be used for repairing internal and external cracks of concrete, is easy to use, can realize multiple triggering, synergistic effect, internal and external crack repair, has good repair effect, and is suitable for large-scale popularization and application.

[0009] To achieve the above objects, in the first aspect of the present application, a double-repair material composite system for internal and external crack self-repairing of concrete is provided, which comprises an internal mixing type composite dry powder repair agent and an external coating type intelligent repair liquid, wherein:

[0010] 1) the internal mixing type composite dry powder repair agent comprises the following components by weight percentage:

[0011] Main material system: high-activity modified silicate 25% by weight to 35% by weight;

[0012] Silica fume 10% by weight to 15% by weight;

[0013] Activation and catalysis system: composite catalyst 3% by weight to 5% by weight, the composite catalyst comprising anhydrous sodium silicate and lithium sulfate, wherein the lithium sulfate is 0.5% by weight to 1% by weight;

[0014] Expansion compensation system: calcium sulphoaluminate expansive agent 8% by weight to 12% by weight;

[0015] Magnesium oxide expansive agent 5% by weight to 8% by weight;

[0016] Physical repair system: epoxy resin microcapsule 5% by weight to 8% by weight;

[0017] Surface modified polypropylene fiber 0.5% by weight to 1.0% by weight;

[0018] Biological repair system: microbial carrier 5% by weight to 8% by weight; the microbial carrier is a porous granular carrier loaded with Paenibacillus peoriae;

[0019] Functional additive system: polycarboxylic acid based superplasticizer 1.5% by weight to 2.5% by weight;

[0020] Dispersant 0.5% by weight to 1.0% by weight;

[0021] The balance is a filler;

[0022] 2) the outer coating type intelligent repair liquid comprises the following components by weight percentage:

[0023] Active penetrating carrier: alkyl alkoxysilane mixture 30% to 40% by weight;

[0024] Fast repair resin system: water-based epoxy-acrylic hybrid emulsion 15% to 20% by weight;

[0025] Latent curing agent 2% to 3% by weight;

[0026] Crystalline repair system: superfine core powder 10% to 15% by weight; the superfine core powder is made by superfine grinding the main material system, and the fineness of the superfine core powder is 800 to 1000 mesh;

[0027] Nano-enhanced system: nano-silica dispersion liquid 3% to 5% by weight;

[0028] Nano calcium carbonate 2% to 4% by weight;

[0029] Color adjustment system: colored active mineral powder 0% to 8% by weight;

[0030] Auxiliary system: wetting agent 0.3% to 0.6% by weight;

[0031] Defoaming agent 0.3% to 0.5% by weight;

[0032] Leveling agent 0.2% to 0.4% by weight;

[0033] Mildew-proof agent 0.1% to 0.3% by weight;

[0034] The balance is water.

[0035] Preferably, CaO≥50% by weight, SiO2≥25% by weight in the high-activity modified silicate, and the specific surface area of the high-activity modified silicate is≥400m 2 / kg; the silica ash has SiO2≥92% by weight, and the average particle size of the silica ash is 0.1-0.2 μm; the magnesium oxide-based intumescent agent has MgO≥85% by weight, and the activity index of the magnesium oxide-based intumescent agent at 80°C is 150-300 s; the wall material of the epoxy resin microcapsule is urea-formaldehyde resin, the core material of the epoxy resin microcapsule is bisphenol A type epoxy resin, the particle size of the epoxy resin microcapsule is 50-100 μm, and the core material loading of the epoxy resin microcapsule is≥70% by weight; the length of the surface-modified polypropylene fiber is 6-12 mm, the diameter of the surface-modified polypropylene fiber is 20-40 μm, and the tensile strength of the surface-modified polypropylene fiber is >500 MPa; the particle size of the microbial carrier is 0.1-0.3 mm, and the porosity of the microbial carrier is >50%; the dispersing agent is sodium hexametaphosphate; or the filler is quartz sand powder, and the fineness of the quartz sand powder is 200-400 mesh.

[0036] Preferably, the microbial carrier is prepared by the following method: sterilizing the porous granular carrier, placing the sterilized porous granular carrier in a Sporolactobacillus pasteurii culture solution, inoculating Sporolactobacillus pasteurii into the Sporolactobacillus pasteurii culture solution, performing oscillation culture, and performing low-temperature vacuum drying on the obtained product to obtain the porous granular carrier loaded with Sporolactobacillus pasteurii.

[0037] Preferably, the epoxy resin microcapsule is prepared by in-situ polymerization.

[0038] More preferably, the in-situ polymerization specifically includes: mixing urea, formaldehyde and emulsified epoxy resin core material, slowly polymerizing under acidic conditions, forming a dense urea-formaldehyde resin wall material on the surface of the emulsified epoxy resin core material, and obtaining the epoxy resin microcapsule with the urea-formaldehyde resin wall material through filtration, washing and low-temperature fluidized bed drying.

[0039] Preferably, the surface-modified polypropylene fiber is prepared by subjecting polypropylene fiber to plasma treatment or alkali roughening treatment.

[0040] Preferably, the mass fraction of isobutyl triethoxysilane in the alkyl alkoxysilane mixture is ≥98%, the penetration depth of the alkyl alkoxysilane mixture is ≥10 mm; the solid content of the water-based epoxy-acrylic hybrid emulsion is 48% to 52% by weight, the pH value of the water-based epoxy-acrylic hybrid emulsion is 7.0 to 9.0; the latent curing agent is a modified amine; the particle size of nano-silica in the nano-silica dispersion is 15 nm to 30 nm, the solid content of the nano-silica dispersion is 30% by weight; the color active mineral powder is selected from at least one of the iron oxide series and chromium oxide green; the wetting agent is a non-ionic wetting agent; the defoaming agent is a silicone-based defoaming agent; and the leveling agent is a polyether-modified polydimethylsiloxane.

[0041] Preferably, the superfine grinding is performed by using an air flow mill or a planetary ball mill.

[0042] In the second aspect of the present application, a preparation method of the above-mentioned dual-repair material composite system for self-repairing internal and external cracks of concrete is provided, which is characterized in that the preparation method comprises a preparation method of an internal-mixing type composite dry powder repair agent and a preparation method of an external-coating type intelligent repair liquid, wherein:

[0043] (1) The preparation method of the internal-mixing type composite dry powder repair agent comprises the following steps:

[0044] (11) Primary mixing:

[0045] The high-activity modified silicate, the silica fume, the calcium sulphoaluminate expansive agent, the magnesium oxide expansive agent, the polycarboxylate superplasticizer, the dispersant, and the filler are uniformly mixed by using medium-speed stirring to obtain a primary mixture;

[0046] (12) Secondary mixing:

[0047] The composite catalyst is added to the primary mixture, and the mixture is uniformly mixed by using low-speed stirring to obtain a secondary mixture;

[0048] (13) Final mixing:

[0049] (131) The microbial carrier and the epoxy resin microcapsule are added to the secondary mixture, and the mixture is uniformly mixed by using even lower-speed stirring;

[0050] (132) The surface-modified polypropylene fiber is added, and the mixture is uniformly mixed by using even lower-speed stirring to obtain the internal-mixing type composite dry powder repair agent;

[0051] (2) The preparation method of the external-coating type intelligent repair liquid comprises the following steps:

[0052] (21) Preparation of an aqueous phase:

[0053] In half weight of the water, the wetting agent, half weight of the defoaming agent, the nano-silica dispersion liquid, the nano calcium carbonate, the color active mineral powder and the ultra-fine core powder are added to carry out high-speed dispersion, to obtain a mixed slurry;

[0054] (22) Emulsion preparation:

[0055] In the remaining water, the water-based epoxy-acrylic hybrid emulsion and the latent curing agent are sequentially added, and low-speed stirring is carried out to mix uniformly;

[0056] Then, the alkyl alkoxysilane mixture is added, and high-speed shearing emulsification is carried out, to obtain an emulsion;

[0057] (23) Paint conditioning and post-treatment:

[0058] The mixed slurry is added into the emulsion, and stirring is carried out to mix uniformly;

[0059] The leveling agent, the remaining defoaming agent and the mildew-proof agent are sequentially added, and low-speed stirring is carried out to mix uniformly, to obtain a mixed product;

[0060] The mixed product is sealed and allowed to stand to mature, and the outer-coating type intelligent repair liquid is obtained after filtration.

[0061] In a third aspect of the present application, the use of the above-mentioned dual repair material composite system for internal and external crack self-repairing of concrete or the dual repair material composite system prepared by the above-mentioned preparation method for internal and external crack self-repairing of concrete is applied to repair internal and external cracks of concrete.

[0062] The beneficial effects of the present application mainly include:

[0063] 1、The dual repair material composite system for internal and external crack self-repairing of concrete comprises an internal-mixing type composite dry powder repair agent and an outer-coating type intelligent repair liquid, the internal-mixing type composite dry powder repair agent comprises high-activity modified silicate, silica fume, a composite catalyst, calcium sulphoaluminate expansive agent, magnesium oxide expansive agent, epoxy resin microcapsule, surface modified polypropylene fiber, microbial carrier, polycarboxylate superplasticizer, dispersant and filler, the composite catalyst comprises anhydrous sodium silicate and lithium sulfate, and the microbial carrier is a porous granular carrier loaded with Bacillus pasteurii; the outer-coating type intelligent repair liquid comprises an alkyl alkoxysilane mixture, a water-based epoxy-acrylic hybrid emulsion, a latent curing agent, an ultra-fine core powder, a nano-silica dispersion liquid, a nano calcium carbonate, a color active mineral powder, a wetting agent, a defoaming agent, a leveling agent, a mildew-proof agent and water, and the ultra-fine core powder is prepared by ultra-fine grinding of high-activity modified silicate and silica fume, so that the dual repair material composite system is simple to use, can realize multiple triggering, synergistic effect, internal and external crack repair, has good repair effect and is suitable for large-scale popularization and application.

[0064] 2. The preparation method of the double-repair material composite system for internal and external crack self-repairing of concrete according to the present application, comprising the preparation method of the internal mixed type composite dry powder repair agent and the preparation method of the external coating type intelligent repair liquid, the preparation method of the internal mixed type composite dry powder repair agent comprising: (11) primary mixing: uniformly mixing high-activity modified silicate, silica fume, calcium sulphoaluminate expansive agent, magnesium oxide expansive agent, polycarboxylate superplasticizer, dispersant and filler by medium-speed stirring to obtain a primary mixture; (12) secondary mixing: uniformly mixing the composite catalyst in the primary mixture by low-speed stirring to obtain a secondary mixture; (13) final mixing: (131) uniformly mixing the microbial carrier and the epoxy resin microcapsule in the secondary mixture by lower-speed stirring; (132) uniformly mixing the surface modified polypropylene fiber in the secondary mixture by low-speed stirring to obtain the internal mixed type composite dry powder repair agent; the preparation method of the external coating type intelligent repair liquid comprising: (21) water phase preparation: dispersing the wetting agent, half weight of the defoaming agent, nano-silicon dioxide dispersion, nano-calcium carbonate, colored active mineral powder and superfine core powder in half weight of water by high-speed dispersion to obtain a mixed slurry; (22) emulsion preparation: uniformly mixing the water-based epoxy-acrylic hybrid emulsion and the latent curing agent in the remaining water by low-speed stirring; then mixing the alkyl alkoxysilane mixture and performing high-speed shearing emulsification to obtain an emulsion; (23) paint conditioning and post-treatment: uniformly stirring the mixed slurry in the emulsion; uniformly stirring the leveling agent, the remaining defoaming agent and the mildewcide by low-speed stirring to obtain a mixed product; sealing, aging and filtering the mixed product to obtain the external coating type intelligent repair liquid, so that the preparation is simple, the double-repair material composite system for internal and external crack self-repairing of concrete is simple to use, multiple triggering, synergistic effect, internal and external crack repairing can be realized, the repairing effect is good, and the system is suitable for large-scale popularization and application.

[0065] 3. The application of the double-repair material composite system for internal and external crack self-repairing of concrete according to the present application, which can be used for repairing internal and external cracks of concrete, is simple to use, can realize multiple triggering, synergistic effect, internal and external crack repairing, has good repairing effect, and is suitable for large-scale popularization and application.

[0066] These and other objects, features and advantages of the present application will become apparent with reference to the following detailed description of the present application, taken in conjunction with the accompanying drawings. DETAILED DESCRIPTION

[0067] In order to overcome the problems of single repair mechanism, harsh repair condition, limited repair effect and unable to repair internal and surface cracks in the prior art, the inventors obtain a double repair material composite system for internal and external crack self-repairing of concrete through continuous research and test, realize long-term and automatic internal crack prevention and repair through internal admixture, realize rapid, accurate and aesthetic repair of surface cracks through external coating liquid, and realize all-round and whole life cycle intelligent maintenance of concrete cracks through synergistic effect of two repair materials.

[0068] The present application firstly provides a double repair material composite system for internal and external crack self-repairing of concrete, comprising internal admixture type composite dry powder repair agent (IMMHA) and external coating type intelligent repair liquid (SSHC), wherein:

[0069] 1) the internal admixture type composite dry powder repair agent comprises the following components by weight percentage:

[0070] main material system: high-activity modified silicate 25% by weight to 35% by weight;

[0071] silica fume 10% by weight to 15% by weight;

[0072] excitation and catalysis system: composite catalyst 3% by weight to 5% by weight, the composite catalyst comprising anhydrous sodium silicate (Na2SiO3) and lithium sulfate (Li2SO4), wherein the lithium sulfate is 0.5% by weight to 1% by weight;

[0073] expansion compensation system: calcium sulphoaluminate expansive agent 8% by weight to 12% by weight;

[0074] magnesium oxide expansive agent 5% by weight to 8% by weight;

[0075] physical repair system: epoxy resin microcapsule 5% by weight to 8% by weight;

[0076] surface modified polypropylene fiber 0.5% by weight to 1.0% by weight;

[0077] biological repair system: microbial carrier 5% by weight to 8% by weight; the microbial carrier is a porous granular carrier loaded with Paenibacillus peoriae;

[0078] functional additive system: polycarboxylic acid based superplasticizer 1.5% by weight to 2.5% by weight;

[0079] dispersant 0.5% by weight to 1.0% by weight;

[0080] the balance is filler;

[0081] 2) the external coating type intelligent repair liquid comprises the following components by weight percentage:

[0082] Active penetrating carrier: alkylalkoxysilane mixture 30-40 wt.%;

[0083] Fast repair resin system: waterborne epoxy-acrylic hybrid emulsion 15-20 wt.%;

[0084] Latent curing agent 2-3 wt.%;

[0085] Crystalline repair system: ultra-fine core powder 10-15 wt.%; the ultra-fine core powder is made by ultra-fine grinding of the main material system, and the fineness of the ultra-fine core powder is 800-1000 mesh;

[0086] Nano-enhanced system: nano-silica (nano-SiO2) dispersion liquid 3-5 wt.%;

[0087] Nano calcium carbonate (nano-CaCO3) 2-4 wt.%;

[0088] Color adjustment system: colored active mineral powder 0-8 wt.%;

[0089] Auxiliary system: wetting agent 0.3-0.6 wt.%;

[0090] Defoaming agent 0.3-0.5 wt.%;

[0091] Leveling agent 0.2-0.4 wt.%;

[0092] Mildew-proof agent 0.1-0.3 wt.%;

[0093] The balance is water.

[0094] The high-activity modified silicate can have any suitable CaO and SiO2 content and specific surface area, preferably CaO≥50 wt.% and SiO2≥25 wt.% in the high-activity modified silicate, and the specific surface area of the high-activity modified silicate is≥400 m 2 / kg.

[0095] The silica fume (special active silica) is a by-product of smelting ferrosilicon alloy, and can have any suitable SiO2 content and average particle size, preferably SiO2≥92 wt.% in the silica fume, and the average particle size of the silica fume is 0.1-0.2 μm.

[0096] The magnesium oxide-based expanding agent can have any suitable MgO content and activity index, preferably MgO≥85 wt.% in the magnesium oxide-based expanding agent, and the activity index of the magnesium oxide-based expanding agent at 80°C is 150-300 s.

[0097] The epoxy resin microcapsule can have any suitable wall material, core material, particle size, and core material loading, preferably the wall material of the epoxy resin microcapsule is urea-formaldehyde resin, the core material of the epoxy resin microcapsule is bisphenol A type epoxy resin, the particle size of the epoxy resin microcapsule is 50 μm to 100 μm, and the core material loading of the epoxy resin microcapsule is ≥ 70% by weight.

[0098] The surface-modified polypropylene fiber can have any suitable length, diameter, and tensile strength, preferably the length of the surface-modified polypropylene fiber is 6 mm to 12 mm, the diameter of the surface-modified polypropylene fiber is 20 μm to 40 μm, and the tensile strength of the surface-modified polypropylene fiber is > 500 MPa.

[0099] The microbial carrier can have any suitable particle size and porosity, preferably the particle size of the microbial carrier is 0.1 mm to 0.3 mm, and the porosity of the microbial carrier is > 50%.

[0100] The dispersant can be any suitable dispersant, preferably the dispersant is sodium hexametaphosphate.

[0101] The filler can be any suitable filler, preferably the filler is quartz sand powder, and the fineness of the quartz sand powder is 200 mesh to 400 mesh.

[0102] The microbial carrier can be prepared by any suitable method, preferably the microbial carrier is prepared by the following method: sterilizing a porous granular carrier and placing it in a Sporosarcina pasteurii culture solution, inoculating Sporosarcina pasteurii into the Sporosarcina pasteurii culture solution, performing shaking culture, and performing low-temperature vacuum drying on the obtained product to obtain a porous granular carrier loaded with Sporosarcina pasteurii.

[0103] The porous granular carrier can be any suitable porous granular carrier, more preferably the porous granular carrier is porous ceramic, and the particle size of the porous ceramic is 0.1 mm to 0.3 mm.

[0104] The temperature, time, and speed of the shaking culture can be determined as needed, more preferably the temperature of the shaking culture is 30°C to 37°C, the time of the shaking culture is 48 hours to 72 hours, and the speed of the shaking culture is 150 rpm to 200 rpm.

[0105] The low-temperature vacuum drying can be performed using any suitable equipment, more preferably the low-temperature vacuum drying is performed using a low-temperature vacuum drying box.

[0106] The temperature of the low-temperature vacuum drying can be determined as needed, more preferably the temperature of the low-temperature vacuum drying is 40°C to 45°C.

[0107] The epoxy microcapsules can be prepared by any suitable method, preferably, the epoxy microcapsules are prepared by in-situ polymerization.

[0108] The in-situ polymerization can comprise any suitable steps, more preferably, the in-situ polymerization comprises the steps of mixing urea, formaldehyde and emulsified epoxy resin core material, slowly polymerizing under acidic conditions to form a dense urea-formaldehyde resin wall material on the surface of the emulsified epoxy resin core material, and filtering, washing and low-temperature fluidized bed drying the reaction product to obtain epoxy microcapsules with a wall material of urea-formaldehyde resin.

[0109] The temperature of the low-temperature fluidized bed drying can be determined as required, more preferably, the temperature of the low-temperature fluidized bed drying is < 50°C.

[0110] The surface-modified polypropylene fibers can be prepared by any suitable method, preferably, the surface-modified polypropylene fibers are prepared by subjecting polypropylene fibers to plasma treatment or alkali roughening treatment.

[0111] The alkylalkoxysilane mixture can have any suitable isobutyl triethoxysilane content and penetration depth, preferably, the alkylalkoxysilane mixture has an isobutyl triethoxysilane content of ≥ 98% by mass, and a penetration depth of ≥ 10 mm.

[0112] The aqueous epoxy-acrylic hybrid emulsion can have any suitable solid content and pH value, preferably, the aqueous epoxy-acrylic hybrid emulsion has a solid content of 48% by weight to 52% by weight, and a pH value of 7.0 to 9.0.

[0113] The latent curing agent can be any suitable latent curing agent, preferably, the latent curing agent is a modified amine.

[0114] The nanosilica dispersion can have nanosilica with any suitable particle size and solid content, preferably, the nanosilica dispersion has nanosilica with a particle size of 15 nm to 30 nm, and a solid content of 30% by weight.

[0115] The colored active mineral powder can be any suitable colored active mineral powder, preferably, the colored active mineral powder is selected from at least one of the iron oxide series (red, yellow, brown) and chromium oxide green.

[0116] The wetting agent can be any suitable type of wetting agent, preferably, the wetting agent is a non-ionic wetting agent.

[0117] The defoaming agent can be any suitable type of defoaming agent, preferably the defoaming agent is a silicone-based defoaming agent.

[0118] The leveling agent can be any suitable leveling agent, preferably the leveling agent is a polyether-modified polydimethylsiloxane.

[0119] The ultrafine grinding can be performed using any suitable equipment, preferably the ultrafine grinding is performed using an air jet mill or a planetary ball mill.

[0120] The water can be any suitable water, preferably the water is deionized water.

[0121] In the present invention, the high-activity modified silicate provides Ca 2+ and SiO4 4- ions, which are the main body of the reaction of generating C-S-H gel; the silica fume has very strong pozzolanic activity, reacts with Ca(OH)2 to generate C-S-H, and refines the pore; Na2SiO3: provides an alkaline environment and stimulates reaction activity; Li2SO4: a high-efficiency catalyst that significantly accelerates the crystallization rate; calcium sulphoaluminate expansive agent generates ettringite (AFt) in the early hydration stage, the amount of ettringite generated can be controlled, and moderate expansion is produced to compensate for the plastic shrinkage and early dry shrinkage of concrete; magnesium oxide expansive agent generates Mg(OH)2 in the middle hydration stage, and the expansion is delayed to compensate for the temperature drop shrinkage of concrete; epoxy resin microcapsules are broken by crack stress, release epoxy resin, and solidify after contacting with water and alkaline environment in concrete, providing instantaneous mechanical bonding; surface-modified polypropylene fibers form a three-dimensional network in concrete to block and toughen, limit the development width of microcracks, and keep them within the effective range of self-repair; after water enters the cracks, the Bacillus pasteurii carried by the microbial carrier is activated, metabolizes urea to produce CO32-, and reacts with Ca 2+ combined with the generation of calcium carbonate crystal (CaCO3) precipitation to block the cracks; polycarboxylate-based high-efficiency water-reducing agent compensates for the loss of fluidity caused by the addition of a large amount of powder materials, and ensures the workability of concrete; dispersant prevents various fine powders from agglomerating during mixing and transportation, and ensures uniformity of ingredients; filler adjusts the overall bulk density, facilitates accurate metering and feeding, and reduces cost.

[0122] In the present application, the alkyl alkoxysilane mixture has ultra-low surface tension, can carry other functional components to penetrate deeply into the crack, and provide excellent hydrophobicity; the water-based epoxy-acrylic hybrid emulsion forms a continuous glue film with high strength and high toughness, quickly seals the crack surface, and provides immediate impermeability and adhesion; the latent curing agent stably coexists with the water-based epoxy-acrylic hybrid emulsion, reacts with CO2 / moisture in the air after brushing, and gradually triggers cross-linking and curing; the ultra-fine core powder provides long-term crystallization growth ability, reacts with unhydrated particles and Ca(OH)2 in the concrete, and realizes permanent repair; the nano-silicon dioxide dispersion liquid fills the micropores, improves the compactness of the coating, and improves the late strength of the repair body through the pozzolanic effect; the nano calcium carbonate acts as a "crystal nucleus" for crystallization and precipitation, accelerates the crystallization process, and optimizes the crystallization morphology; the color active mineral powder has excellent alkali resistance and weather resistance, and is matched with the color of the concrete base according to the engineering requirements, so that the "visual invisibility" effect is realized after repair; the wetting agent greatly reduces the surface tension of the system, ensures the sufficient wetting and spreading of the system on the dry concrete base; the defoaming agent inhibits the generation of bubbles in the production and brushing process, and avoids the formation of defects in the coating; the leveling agent makes the coating have good leveling property, and the paint film is uniform and flat; the mildew-proof agent prevents the product from mildewing during storage and use; and the water is an environmentally friendly solvent for dissolving and loading various components.

[0123] The present application also provides a preparation method of the above-mentioned dual-repair material composite system for self-repairing internal and external cracks of concrete, including a preparation method of an internal-mixing type composite dry powder repair agent and a preparation method of an external-coating type intelligent repair liquid.

[0124] (1) The preparation method of the internal-mixing type composite dry powder repair agent comprises the following steps:

[0125] (11) Primary mixing:

[0126] The high-activity modified silicate, the silica fume, the calcium sulphoaluminate expansive agent, the magnesium oxide expansive agent, the polycarboxylate superplasticizer, the dispersant and the filler are uniformly mixed by medium-speed stirring to obtain a primary mixture;

[0127] (12) Secondary mixing:

[0128] The composite catalyst is added to the primary mixture, and the secondary mixture is obtained by uniformly mixing at low speed;

[0129] (13) Final mixing:

[0130] (131) The microbial carrier and the epoxy resin microcapsule are added to the secondary mixture, and the final mixture is obtained by uniformly mixing at a lower speed;

[0131] (132) the surface modified polypropylene fibers are added, mixed uniformly at a lower speed, to obtain the internal mixing type composite dry powder repair agent;

[0132] (2) the preparation method of the external coating type intelligent repair liquid comprises the following steps:

[0133] (21) water phase preparation:

[0134] In half of the weight of the water, the wetting agent, half of the weight of the defoaming agent, the nano-silica dispersion liquid, the nano-calcium carbonate, the colored active mineral powder and the ultra-fine core powder are added and dispersed at a high speed to obtain a mixed slurry;

[0135] (22) emulsion preparation:

[0136] In the remaining water, the water-based epoxy-acrylic hybrid emulsion and the latent curing agent are sequentially added and mixed uniformly at a low speed;

[0137] Then the alkyl alkoxysilane mixture is added and high-speed shearing emulsification is performed to obtain an emulsion;

[0138] (23) paint conditioning and post-treatment:

[0139] The mixed slurry is added to the emulsion and stirred uniformly;

[0140] The leveling agent, the remaining defoaming agent and the mildewcide are sequentially added and stirred uniformly at a low speed to obtain a mixed product;

[0141] The mixed product is sealed and allowed to mature, and the external coating type intelligent repair liquid is obtained after filtration.

[0142] In the step (11), the speed and time of the medium-speed stirring can be determined as required, preferably, in the step (11), the speed of the medium-speed stirring is 15 rpm-20 rpm, and the time of the medium-speed stirring is 15 minutes-20 minutes.

[0143] In the step (12), the speed and time of the low-speed stirring can be determined as required, preferably, in the step (12), the speed of the low-speed stirring is 8 rpm-12 rpm, and the time of the low-speed stirring is 5 minutes-8 minutes.

[0144] In the step (131), the speed and time of the lower-speed stirring can be determined as required, preferably, in the step (131), the speed of the lower-speed stirring is 5 rpm-8 rpm, and the time of the lower-speed stirring is 3 minutes-5 minutes.

[0145] The speed and time of the lower speed stirring in the step (132) can be determined as required, preferably, the speed of the lower speed stirring in the step (132) is 5 rpm to 8 rpm, and the time of the lower speed stirring in the step (132) is 2 minutes to 3 minutes.

[0146] The speed and time of the high speed dispersion in the step (21) can be determined as required, preferably, the speed of the high speed dispersion in the step (21) is 1500 rpm to 2000 rpm, and the time of the high speed dispersion in the step (21) is 20 minutes to 30 minutes.

[0147] The speed and time of the low speed stirring in the step (22) can be determined as required, preferably, the speed of the low speed stirring in the step (22) is 100 rpm to 200 rpm, and the time of the low speed stirring in the step (22) is 10 minutes.

[0148] The speed and time of the high speed shearing in the step (22) can be determined as required, preferably, the speed of the high speed shearing in the step (22) is 3000 rpm to 4000 rpm, and the time of the high speed shearing in the step (22) is 15 minutes to 20 minutes.

[0149] The speed and time of the stirring in the step (23) can be determined as required, preferably, the speed of the stirring in the step (23) is 800 rpm to 1000 rpm, and the time of the stirring in the step (23) is 15 minutes.

[0150] The speed and time of the low speed stirring in the step (23) can be determined as required, preferably, the speed of the low speed stirring in the step (23) is 300 rpm to 500 rpm, and the time of the low speed stirring in the step (23) is 10 minutes.

[0151] The sealed standing ripening in the step (23) can be performed by using any suitable equipment, and the time of the sealed standing ripening can be determined as required, preferably, the sealed standing ripening in the step (23) is performed by using a ripening tank, and the time of the sealed standing ripening is 24 hours.

[0152] The filtration in the step (23) can be performed by using any suitable device, preferably, the filtration in the step (23) is performed by using a 200 mesh vibrating screen or a bag filter.

[0153] The application further provides the application of the double-repair material composite system for self-repairing internal and external cracks of concrete in repairing internal and external cracks of concrete.

[0154] In order to enable the technical contents of the present application to be more clearly understood, the following examples are described in detail. It should be understood that the specific examples described herein are merely intended to explain the present application and are not intended to limit the present application. Unless otherwise specified, the instruments, drugs, reagents and the like used in the following examples can be obtained by conventional commercial means.

[0155] Preparation of the internal mixing type composite dry powder repair agent (IMMHA)

[0156] The core of the production of IMMHA is grading mixing, which ensures that each component, especially the fragile functional components (epoxy resin microcapsules, microbial carriers), is uniformly distributed and not damaged.

[0157] Detailed production process flow:

[0158] First stage: raw material pretreatment and preparation

[0159] 1. Preparation and immobilization of microbial carriers:

[0160] Place: in a sterile laboratory or clean room.

[0161] Step: After sterilization, the porous ceramic particles (particle size 0.2 mm) are placed in a Sporosarcina pasteurii culture solution. In a bioreactor with controlled temperature (35℃), humidity and aeration, Sporosarcina pasteurii is inoculated and cultured at 150 rpm for 60 hours to allow Sporosarcina pasteurii to fully adsorb and immobilize in the pores of the porous ceramic particles.

[0162] Drying: then the porous ceramic particles loaded with Sporosarcina pasteurii are sent to a low-temperature vacuum drying oven (43℃) for drying to make them dormant. After drying, they are sealed and stored in a cold storage for standby.

[0163] 2. Preparation of epoxy resin microcapsules:

[0164] Method: in-situ polymerization method.

[0165] Step: in a reaction kettle, urea, formaldehyde and emulsified bisphenol A type epoxy resin core material are mixed and slowly polymerized under acidic conditions to form a dense urea-formaldehyde resin wall material on the surface of the emulsified bisphenol A type epoxy resin core material.

[0166] Post-treatment: After the reaction, filter, wash, low temperature fluidized bed drying (45℃), get good flowability of microcapsule powder. Screening out 50-100 μm target product, epoxy resin microcapsule core material load is 75% by weight.

[0167] 3. Surface treatment of polypropylene fiber:

[0168] Method: Plasma treatment.

[0169] Step: polypropylene fiber through plasma treatment equipment, in high frequency electric field, treatment gas (such as air, oxygen) is ionized, produce high activity particles bombardment fiber surface, make it from hydrophobic to hydrophilic, and produce etching, increase roughness.

[0170] Second stage: accurate metering and grading mixing

[0171] Equipment: large three-dimensional multi-directional motion mixer (such as double cone mixer, V-type mixer), this embodiment specifically adopts double cone mixer, the equipment mixing efficiency is high, no dead angle, to the material is mild, will not produce high heat or shear damage.

[0172] Intrusive type composite dry powder repair agent formula:

[0173] Main material system: high activity modified silicate 30% by weight;

[0174] Silica 12% by weight;

[0175] Excitation and catalyst system: composite catalyst 4% by weight, composite catalyst includes anhydrous sodium silicate and lithium sulfate, wherein lithium sulfate is 0.8% by weight, anhydrous sodium silicate is 3.2% by weight;

[0176] Expansion compensation system: calcium sulphoaluminate expansion agent 10% by weight;

[0177] Magnesium oxide expansion agent 6% by weight;

[0178] Physical repair system: epoxy resin microcapsule 6% by weight;

[0179] Surface modified polypropylene fiber 0.8% by weight;

[0180] Biological repair system: microbial carrier 6% by weight;

[0181] Functional additive system: polycarboxylic acid type high efficiency water reducing agent 2% by weight;

[0182] Dispersant 0.8% by weight;

[0183] Filler 22.4% by weight.

[0184] Mixing process:

[0185] 1. Primary mixing (macro-material mixing):

[0186] Highly active modified silicate, silica fume, calcium sulphoaluminate expansive agent, magnesium oxide expansive agent, polycarboxylate superplasticizer, dispersant (sodium hexametaphosphate), and filler (quartz sand powder, fineness 300 mesh) (macro-materials) are put into the mixer.

[0187] Set the medium speed 18 rpm and mix for 18 minutes to ensure uniform mixing.

[0188] 2. Secondary mixing (pre-mixing of small materials):

[0189] Stop the mixer and add the composite catalyst.

[0190] Restart the mixer and mix at low speed 10 rpm for 6 minutes to ensure uniform dispersion of these components in the masterbatch.

[0191] 3. Final mixing (addition of fragile components):

[0192] Stop the mixer and add the most fragile microbial carrier (particle size 0.2 mm, porosity 70%) and epoxy resin microcapsules.

[0193] Make sure to use lower speed 6 rpm stirring for 4 minutes. Prolonged mixing time or high speed can cause the epoxy resin microcapsules to break and the microbial carrier to wear out.

[0194] Fiber addition:

[0195] Under the running state of the mixer, slowly and evenly sprinkle the treated surface-modified polypropylene fibers (length 10 mm, diameter 30 μm, tensile strength > 500 MPa) through a dedicated fiber feeder.

[0196] Continue to mix at lower speed 6 rpm for 3 minutes to ensure dispersion of the fiber filaments without agglomeration.

[0197] Third stage: packaging and storage

[0198] Packaging: The uniformly mixed finished product is transported through airtight pipeline to a fully automatic packaging machine. It must be sealed and packaged using moisture-proof aluminum foil composite bags, as the product will react prematurely and lose activity after absorbing moisture.

[0199] Storage: Store in a cool (<30°C), dry (humidity <50% RH) warehouse, avoiding direct sunlight. Do not stack too high to prevent crushing of the microcapsules.

[0200] Preparation of Example 2: Exterior-coated intelligent repair liquid (SSHC)

[0201] The production core of SSHC is high-speed shearing emulsification, which stably integrates the incompatible organosilane, resin emulsion and water phase into one, forming a uniform and stable emulsion.

[0202] Production process flow details:

[0203] Formula of the outer-coated intelligent repair liquid:

[0204] Active permeation carrier: alkyl alkoxysilane mixture 35% by weight;

[0205] Fast repair resin system: water-based epoxy-acrylic hybrid emulsion 18% by weight;

[0206] Latent curing agent 2.5% by weight;

[0207] Crystal repair system: ultra-fine core powder 12% by weight;

[0208] Nanometer reinforced system: nano-silica dispersion liquid 4% by weight;

[0209] Nano calcium carbonate 3% by weight;

[0210] Color adjustment system: colored active mineral powder 3% by weight;

[0211] Auxiliary system: wetting agent 0.4% by weight;

[0212] Defoamer 0.4% by weight;

[0213] Leveling agent 0.3% by weight;

[0214] Mildew-proof agent 0.2% by weight;

[0215] Deionized water 21.2% by weight.

[0216] Ultra-fine core powder is made by ultra-fine grinding of the main material system of the internal doped composite dry powder repair agent. Ultra-fine grinding:

[0217] Equipment: jet mill (or planetary ball mill).

[0218] Step: The mixture of high-activity modified silicate and silica fume is crushed to a particle size distribution D90≤15μm (about 800 mesh or more) to improve its reactivity.

[0219] First stage: preparation of water phase

[0220] 1. Pre-dispersion of nano slurry:

[0221] Equipment: high-speed disperser (with sawtooth dispersing disc).

[0222] Procedure: Add half of the formulation amount of deionized water into the dispersing tank, start the disperser (600 rpm). Add nonionic wetting agent, silicone defoamer (half of the amount), nano-silica dispersion, nano-CaCO3, color active mineral powder (iron oxide series (red, yellow, brown) and chromium oxide green) and ultra-fine core powder in sequence.

[0223] High speed dispersion: Increase the speed to 1800 rpm and continue for 25 minutes until the slurry is uniform and fine, without visible particles and agglomerates, obtaining a mixed slurry.

[0224] Second stage: Emulsion preparation

[0225] Base mixture:

[0226] Equipment: Jacketed emulsification reactor (equipped with low speed stirring and high shear emulsifier).

[0227] Procedure: Add the remaining deionized water into the reactor. Start the low speed anchor stirring (150 rpm) and add the aqueous epoxy-acrylic hybrid emulsion, latent curing agent (modified amine) in sequence, stirring for 10 minutes to mix them well.

[0228] High speed shear emulsification:

[0229] Start the high shear emulsifier (rotor-stator structure). Slowly increase the speed to 3500 rpm.

[0230] Slowly and uniformly add the alkylalkyoxysilane mixture into the reactor by vacuum suction or peristaltic pump. This process is critical, the high speed shear force will tear the silane into micron-sized droplets, which are stably wrapped in water by the emulsifier to form an emulsion. This process needs to be maintained for 18 minutes.

[0231] Third stage: Paint conditioning and post-treatment

[0232] Mixing: Adjust the speed back to 900 rpm. Slowly add the mixed slurry prepared in the first stage, stirring for 15 minutes to mix them well.

[0233] Additives addition: Add the leveling agent (polyether modified polydimethylsiloxane), the remaining silicone defoamer and the mildewcide in sequence, stirring at low speed 900 rpm for 10 minutes.

[0234] Maturation: Stop stirring, pump the product into a static maturation tank, seal and let stand for 24 hours. This process allows the bubbles in the system to escape, the reaction to be fully completed and to reach the final stable state.

[0235] Filtration and packaging: After maturation, filter with a 200 mesh vibrating screen (or bag filter) to remove the possible small amount of gel particles. The final product is packed in plastic barrels.

[0236] Example 3: Application of IMMHA in high-performance underground engineering concrete

[0237] Implementation process: In the C50 P12 side wall concrete of the subway station, the total amount of cementitious materials is 450 kg / m 3 , and the IMMHA prepared in Example 1 is added at a dosage of 2.5% (i.e. 11.25 kg / m 3 ). The cement, mineral powder, fly ash, aggregate and water reducing agent are stirred together, and the stirring time is extended by 60 seconds. The pouring, vibrating and curing processes are carried out according to the conventional procedures.

[0238] Test method:

[0239] GB / T 50448-2015 "Application Technical Specification for Cement-based Grouting Materials"

[0240] JGJ / T 23-2011 "Technical Specification for Testing Concrete Compressive Strength by Rebound Method"

[0241] Implementation effect:

[0242] Workability: The concrete slump is maintained at 200 ± 20 mm, the spread is 500 ± 30 mm, and the workability is good without segregation and bleeding.

[0243] Mechanical properties: The 28-day compressive strength reaches 62.5 MPa, which is about 8% higher than that of the reference group (without IMMHA), indicating that IMMHA has an active enhancement effect.

[0244] Durability: The 28-day electric flux test value is 850 coulombs, which is much lower than the requirement of 1000 coulombs in the "Concrete Durability Test and Evaluation Standard", indicating that it has strong resistance to chloride ion penetration.

[0245] Self-repairing performance: After 28 days, the test block is split to induce a crack (width 0.15 mm) and placed in water for 3 days. The ultrasonic detection shows that the wave velocity recovery rate is more than 95%; the crack is completely filled with white dense crystalline material when the test block is cut open; the secondary impermeability pressure test shows that there is no significant difference in the impermeability pressure of the repaired test piece and the intact test piece.

[0246] Example 4: Application of SSHC in the repair of cracks on the overflow surface of a reservoir dam

[0247] Implementation process: A plurality of shrinkage cracks with a width of 0.1-0.3 mm appeared on the overflow surface of the reservoir concrete dam body were repaired. During construction, first, the surface of the cracks was cleaned with a high-pressure water gun (pressure 20 MPa) to remove floating dust and biological membrane, and naturally air-dried until the surface was free of water. Low-viscosity epoxy resin mortar was used to pre-grout and seal cracks with a width >0.3 mm. Then, the SSHC prepared in Example 2 was mixed to gray with a roller and uniformly brushed on the entire overflow surface at a coating amount of 0.8 kg / m 2 , and the brushing was repeated twice at an interval of 6 hours. The construction environment temperature was 15-25℃.

[0248] Test method:

[0249] DL / T 5150-2017 "Test Code for Hydraulic Concrete" or JTJ / T 271-99 "Test Code for Water Transport Engineering Concrete"

[0250] Implementation effect:

[0251] Construction property: The liquid viscosity was moderate, the brushing was smooth, and there was no sagging phenomenon. The surface was dry after 6 hours, and walking was possible after 24 hours.

[0252] Apparent effect: After repair, the surface color was uniform and consistent, the crack traces completely disappeared, the color matching degree with the original concrete was high, and the color difference ΔE was <2.0 (difficult to distinguish with the naked eye).

[0253] Performance verification: After 7 days of repair, the repair area was detected by a water permeation instrument, and the water permeation amount was zero. After experiencing a flood season (6 months), re-examination showed that there was no peeling, cracking, or leakage in the repair area, and the surface hydrophobic effect was obvious (water bead effect was significant).

[0254] Example 5: Synergistic application of a dual-repair material composite system for internal and external crack self-repair of concrete in the joint of a precast concrete member

[0255] Implementation process: In the production of large bridge precast box girders, 3% of the IMMHA prepared in Example 1 was added to the C60 non-shrinkage grouting material used at the joint. After the installation of the member in place, hairline cracks (width <0.1 mm) appeared on the surface of some joints due to stress concentration. For these surface cracks, a fine brush was used to dip the SSHC prepared in Example 2 without color adjustment (original color) and accurately brush it on the cracks to allow it to fully penetrate.

[0256] Test method:

[0257] GB / T 7921-2008 "Uniform Color Space and Color Difference Formula" or ASTM D2244-22 "Instrumental Color Difference Measurement of Non-Transparent Materials"

[0258] Implementation effect:

[0259] Internal self-healing: The free expansion rate of grout 56d doped with IMMHA is controlled at 0.02%-0.04%, effectively ensuring the tightness of the joint. Core drilling sampling shows that the internal structure is dense.

[0260] Surface repair: After 24 hours of SSHC brushing, the surface cracks completely disappear. The repaired area is tested by a rebound hammer, and the surface strength is consistent with the surrounding area.

[0261] Synergistic advantage: This application embodies the perfect synergy of the system - IMMHA prevents and repairs possible microscopic damage from the inside, while SSHC serves as the "last line of defense" to deal with any minor defects that may appear on the surface, while ensuring the beauty and durability of the structure.

[0262] As demonstrated by the above examples, the dual repair material composite system provided by the present application has the following effects:

[0263] High repair success rate: For cracks less than 0.4mm, the repair success rate is >95%.

[0264] Fast repair speed: The surface drying time of the topcoat is <2 hours, and the initial curing time after the microcapsule ruptures is <24 hours.

[0265] Strong durability: The repair product is resistant to acid and alkali, has good weather resistance, and can have the same service life as concrete.

[0266] Convenient construction: The internal admixture is integrated with the concrete, and the topcoat can be brushed or rolled, without the need for special equipment.

[0267] High comprehensive benefit: Although the initial cost is slightly increased, the structure life can be significantly extended, the maintenance cost in the later period can be reduced, and the whole life cycle cost is significantly reduced.

[0268] Compared with the prior art, the present application has the following significant advantages:

[0269] Multi-mechanism synergy: It combines four repair mechanisms of chemical crystallization, mineral expansion, physical adhesion (fiber, resin), and biological mineralization, overcoming the limitations of single mechanism, with extremely high repair success rate and efficiency.

[0270] Internal and external double repair: IMMHA is responsible for internal and spontaneous repair, and SSHC is responsible for surface and active repair, forming a complete protection system.

[0271] Intelligent repeated triggering: The crystallization and biological repair mechanisms are repeatedly activated by water, providing lifelong repair capability.

[0272] Improved comprehensive performance: Not only cracks are repaired, but the internal doped fibers and expanding agents also improve the toughness and crack resistance of concrete, reducing cracks from the source.

[0273] Aesthetic and practical: the outer coating liquid can be color-adjusted to realize "visual invisibility" after repair and meet the aesthetic needs of high-grade buildings.

[0274] Therefore, the application discloses a double-repair material composite system for internal and external crack self-repairing of concrete, which can automatically, intelligently and multi-collaboratively repair internal and surface cracks of concrete, realizes long-term and automatic internal crack prevention and repair through internal admixture, realizes rapid, accurate and aesthetic repair of surface cracks through outer coating liquid, and realizes all-round and full-life-cycle intelligent maintenance of concrete cracks through the synergistic effect of the two repair materials.

[0275] In conclusion, the double-repair material composite system for internal and external crack self-repairing of concrete is simple to use, can realize multi-triggering, synergistic effect and internal and external crack repair, has good repair effect, and is suitable for large-scale popularization and application.

[0276] It can be seen that the purpose of the application has been completely and effectively realized. The function and structure principle of the application have been shown and described in the embodiments, and the implementation manner can be modified arbitrarily without departing from the principle. Therefore, the application includes all modified implementation manners based on the spirit and scope of the claims.

Claims

1. A dual-repair material composite system for self-repairing internal and external cracks in concrete, characterized in that, This includes internally blended composite dry powder repair agents and externally applied intelligent repair liquids, among which: 1) The internally-admixed composite dry powder repair agent comprises the following components by weight percentage: Main ingredient system: 25%–35% by weight of highly active modified silicate; Silica fume 10% to 15% by weight; Excitation and catalytic system: 3% to 5% by weight of composite catalyst, wherein the composite catalyst comprises anhydrous sodium silicate and lithium sulfate, wherein the lithium sulfate comprises 0.5% to 1% by weight; Expansion compensation system: 8% to 12% by weight of calcium sulfoaluminate-based expansion agent; Magnesium oxide-based expanding agents: 5% to 8% by weight; Physical repair system: 5% to 8% by weight of epoxy resin microcapsules; Surface-modified polypropylene fibers: 0.5% to 1.0% by weight; Bioremediation system: 5% to 8% by weight of microbial carrier; the microbial carrier is a porous particulate carrier loaded with Bacillus pasteurellii; Functional additive system: 1.5% to 2.5% by weight of polycarboxylate superplasticizer; Dispersant 0.5% to 1.0% by weight; The remainder is filler material; 2) The topical intelligent repair solution comprises the following components by weight percentage: Active permeation carrier: 30%–40% by weight of alkylalkoxysilane mixture; Rapid repair resin system: 15%–20% by weight of waterborne epoxy-acrylic hybrid emulsion; Latent curing agent: 2% to 3% by weight; Crystallization repair system: 10% to 15% by weight of ultrafine core powder; the ultrafine core powder is made by ultrafine grinding of the main material system, and the fineness of the ultrafine core powder is 800 mesh to 1000 mesh; Nano-reinforced system: 3%–5% by weight of nano-silica dispersion; Nano-calcium carbonate 2% to 4% by weight; Color adjustment system: 0% to 8% by weight of colored active mineral powder; Additive system: wetting agent 0.3% to 0.6% by weight; Defoamer 0.3% to 0.5% by weight; Leveling agent 0.2% to 0.4% by weight; Mildew inhibitor: 0.1% to 0.3% by weight; The remainder is water.

2. The dual-repair material composite system for self-repairing internal and external cracks in concrete as described in claim 1, characterized in that, The highly active modified silicate contains ≥50% CaO and ≥25% SiO2 by weight, and has a specific surface area ≥400 m². 2 / kg; the silica fume contains SiO2 ≥ 92% by weight, and the average particle size of the silica fume is 0.1μm~0.2μm; the magnesium oxide expanding agent contains MgO ≥ 85% by weight, and the activity index of the magnesium oxide expanding agent at 80℃ is 150s~300s; the wall material of the epoxy resin microcapsules is urea-formaldehyde resin, the core material of the epoxy resin microcapsules is bisphenol A type epoxy resin, the particle size of the epoxy resin microcapsules is 50μm~100μm, and the core material of the epoxy resin microcapsules is... The loading capacity is ≥70% by weight; the length of the surface-modified polypropylene fiber is 6mm to 12mm, the diameter of the surface-modified polypropylene fiber is 20μm to 40μm, and the tensile strength of the surface-modified polypropylene fiber is >500MPa; the particle size of the microbial carrier is 0.1mm to 0.3mm, and the porosity of the microbial carrier is >50%; the dispersant is sodium hexametaphosphate; or, the filler is quartz sand powder, and the fineness of the quartz sand powder is 200 mesh to 400 mesh.

3. The dual-repair material composite system for self-repairing internal and external cracks in concrete as described in claim 1, characterized in that, The microbial carrier is prepared by the following method: after sterilizing the porous particulate carrier, it is placed in the culture medium of Bacillus pasteurellii, Bacillus pasteurellii is inoculated into the culture medium of Bacillus pasteurellii, and shake culture is carried out. The obtained product is dried under low temperature vacuum to obtain the porous particulate carrier loaded with Bacillus pasteurellii.

4. The dual-repair material composite system for self-repairing internal and external cracks in concrete as described in claim 1, characterized in that, The epoxy resin microcapsules were prepared by in-situ polymerization.

5. The dual-repair material composite system for self-repairing internal and external cracks in concrete as described in claim 4, characterized in that, The in-situ polymerization method specifically includes: mixing urea, formaldehyde and emulsified epoxy resin core material, slowly polymerizing under acidic conditions to form a dense urea-formaldehyde resin wall material on the surface of the emulsified epoxy resin core material, and obtaining epoxy resin microcapsules with urea-formaldehyde resin wall material by filtration, washing and low-temperature fluidized bed drying of the reaction product.

6. The dual-repair material composite system for self-repairing internal and external cracks in concrete as described in claim 1, characterized in that, The surface-modified polypropylene fiber is made by plasma treatment or alkali roughening treatment of polypropylene fiber.

7. The dual-repair material composite system for self-repairing internal and external cracks in concrete as described in claim 1, characterized in that, The alkylalkoxysilane mixture contains ≥98% isobutyltriethoxysilane by mass, and the penetration depth of the alkylalkoxysilane mixture is ≥10 mm; the aqueous epoxy-acrylic hybrid emulsion has a solid content of 48% to 52% by weight, and the pH value of the aqueous epoxy-acrylic hybrid emulsion is 7.0 to 9.0; the latent curing agent is a modified amine; the nano silica dispersion has a particle size of 15 nm to 30 nm, and the solid content of the nano silica dispersion is 30% by weight; the colored active mineral powder is selected from at least one of the iron oxide series and chromium oxide green; the wetting agent is a nonionic wetting agent; the defoamer is an organosilicon defoamer; and the leveling agent is polyether-modified polydimethylsiloxane.

8. The dual-repair material composite system for self-repairing internal and external cracks in concrete as described in claim 1, characterized in that, The ultrafine grinding is carried out using an air jet mill or a planetary ball mill.

9. A method for preparing a dual-repair material composite system for self-repairing internal and external cracks in concrete as described in claim 1, characterized in that, This includes methods for preparing internally-blended composite dry powder repair agents and methods for preparing externally-applied intelligent repair solutions, wherein: (1) The preparation method of the internally doped composite dry powder repair agent includes the following steps: (11) Primary mixing: The highly active modified silicate, silica fume, calcium sulfoaluminate-based expanding agent, magnesium oxide-based expanding agent, polycarboxylate-based high-efficiency water-reducing agent, dispersant, and filler are mixed evenly at medium speed to obtain a primary mixture; (12) Secondary mixing: The composite catalyst is added to the primary mixture and mixed uniformly by low-speed stirring to obtain a secondary mixture. (13) Final Mixing: (131) Add the microbial carrier and the epoxy resin microcapsules to the secondary mixture and mix them evenly using a lower stirring speed; (132) Add the surface-modified polypropylene fiber and mix evenly with a lower speed to obtain the internally doped composite dry powder repair agent. (2) The preparation method of the externally applied intelligent repair solution includes the following steps: (21) Preparation of aqueous phase: The wetting agent, the defoamer, the nano silica dispersion, the nano calcium carbonate, the colored active mineral powder, and the ultrafine core powder are added to half the weight of the water and dispersed at high speed to obtain a mixed slurry. (22) Emulsion preparation: Add the waterborne epoxy-acrylic hybrid emulsion and the latent curing agent sequentially to the remaining water, and stir at low speed until they are evenly mixed; Then the alkylalkoxysilane mixture is added, and high-speed shear emulsification is performed to obtain an emulsion; (23) Paint mixing and post-treatment: Add the mixed slurry to the emulsion and stir until homogeneous; The leveling agent, the remaining defoamer, and the mildew inhibitor are added sequentially and stirred at low speed until homogeneous to obtain a mixed product; The mixture was sealed and allowed to stand for aging, then filtered to obtain the externally applied intelligent repair solution.

10. The application of the dual-repair material composite system for self-repair of internal and external cracks in concrete prepared by any one of the methods described in claims 1 to 8, or the dual-repair material composite system for self-repair of internal and external cracks in concrete prepared by the method described in claim 9, in repairing internal and external cracks in concrete.