Anti-seepage repairing material for building expansion joints and preparation method of anti-seepage repairing material

Abstract

The invention discloses an anti-seepage repairing material for building expansion joints and a preparation method, and belongs to the technical field of building engineering materials. The anti-seepage repairing material comprises the following components in parts by weight: 8-12 parts of nano modified polyurethane acrylate; 5-8 parts of bio-based modified acrylate; 3-6 parts of modified lignin; 4-7 parts of environment-friendly asphalt; 4-7 parts of high-performance Portland cement; 8-12 parts of an intumescent inorganic mineral composition; 1-2 parts of a microcapsule self-repairing component; 1-3 parts of a functional fiber reinforced material; 55 to 65 parts of two-component nano modified machine-made sand; 0.8-1.2 parts of an organic silicon modified polyether end-capping reagent; and 0.5-1.5 parts of a multifunctional composite catalyst system.

Description

Technical Field

[0001] This application relates to the technical field of building engineering materials, and more specifically, to a waterproof repair material for building expansion joints and a preparation method thereof. Background Art

[0002] During the long-term service of buildings, affected by various factors such as temperature changes, foundation settlement, and structural loads, displacements or deformations of certain degrees will inevitably occur between its components. To avoid cracks or other damages caused by restricted deformation of the structure, expansion joints are usually set at key parts such as beam plates, road surfaces, tunnels, and bridge decks to buffer deformation and release stress. However, although the expansion joint structure has functionality, it is also prone to become a weak link for rainwater leakage, chloride salt erosion, and pollutant intrusion. Especially under heavy traffic or complex climate conditions, its sealing performance and durability are often severely tested.

[0003] To improve the waterproof and durable performance of building expansion joints, materials such as sealants, modified asphalt, and epoxy resins are currently often used to seal or repair the expansion joints. However, these traditional materials generally have problems such as poor adhesion, insufficient durability, and easy aging and cracking, and it is difficult to meet the usage scenarios of long-term service and frequent deformation. In addition, some materials rely on solvents or high-temperature treatment during the construction process, and there are problems such as environmental protection hazards or large operation difficulties, which also limit their popularization and application under complex working conditions.

[0004] With the extension of the service life of building structures and the increasing emphasis on structural safety, researchers have gradually turned their attention to the development of new high-performance materials, such as introducing new technologies such as nano-reinforcing agents, bio-based components, and self-healing microcapsules to improve the mechanical properties, environmental adaptability, and repair ability of the materials. Although some composite materials have been tried and applied to the repair of expansion joints at present, there are still problems such as unreasonable component ratios, complex preparation processes, and poor adaptability to on-site construction, and there is still a gap from engineering practicality.

[0005] In summary, how to develop a new composite material with stable performance, environmental friendliness, good adhesiveness and self-healing ability, and suitable for the waterproof repair of building expansion joints and its preparation method has become an urgent technical problem to be solved. Summary of the Invention

[0006] In order to overcome a series of defects existing in the prior art, the purpose of this application is to provide an anti-seepage repair material for building expansion joints in view of the above problems. By weight, the anti-seepage repair material comprises the following components: 8-12 parts of nano-modified polyurethane acrylate; 5-8 parts of bio-based modified acrylate; 3-6 parts of modified lignin; 4-7 parts of environmentally friendly asphalt; 4-7 parts of high-performance portland cement; 8-12 parts of expansive inorganic mineral combination; 1-2 parts of microcapsule self-healing component; 1-3 parts of functionalized fiber reinforcement material; 55-65 parts of two-component nano-modified manufactured sand; 0.8-1.2 parts of organosilicon-modified polyether end-capping agent; 0.5-1.5 parts of multi-functional composite catalyst system.

[0007] Preferably, the nano-modified polyurethane acrylate is prepared by the following steps: heating the polyurethane acrylate to 60-70 °C, adding 1-3% by weight of amino-modified nano-silica particles thereto under stirring conditions, continuously heating to 80-90 °C, stirring and reacting for 2-4 hours, and then cooling to room temperature to obtain.

[0008] Preferably, the general formula structure of the nano-modified polyurethane acrylate is represented as: PU-(CH2CHCOO) n +SiO2-NH2, wherein: PU is a polyester-type or polyether-type polyurethane chain segment; n = 2-5.

[0009] Preferably, the bio-based modified acrylate is prepared by the following steps: adding 15-25% by weight of soybean oil fatty acid derivatives and 5-10% by weight of hemp seed oil fatty acid esters to the polyacrylate, and stirring and reacting at 70-80 °C for 3-5 hours under nitrogen protection to obtain.

[0010] Preferably, the general formula of the bio-based modified acrylate is: PAA-[COOCH2(CH=CH) x R] m , wherein, PAA is the polyacrylate main chain; x = 1-2; R is a natural fatty acid group; m is the degree of substitution, m = 0.15-0.35.

[0011] Preferably, the modified lignin is obtained by mixing lignin and maleic anhydride in a weight ratio of 3:1-5:1, carrying out an esterification reaction at 150-170 °C for 2-3 hours, and then carrying out a ring-opening reaction with epoxy resin in a weight ratio of 2:1-4:1 for 1-2 hours.

[0012] Preferably, the general formula structure of the modified lignin is: Lignin-OCOCH=CHCOO-[CH2CH(OH)CH2] p , wherein: Lignin is a lignin group; p represents the length of the epoxy chain segment, p = 1–4.

[0013] Preferably, the environment-friendly asphalt is prepared by mixing biomass pyrolysis oil and petroleum asphalt in a weight ratio of 3:7 - 5:5 and adding 1 - 3% of SBS modifier.

[0014] Preferably, the expandable inorganic mineral combination comprises the following components: expanded perlite powder, bentonite, silica fume and magnesia, and their weight ratio is (3 - 5):(2 - 4):(2 - 3):(1 - 2).

[0015] Preferably, the microcapsule self-healing component is an epoxy resin curing agent encapsulated by polyurea microcapsules. The diameter of the microcapsules is 50 - 200 μm, the wall thickness is 2 - 5 μm, and the curing agent is released when the microcapsules are ruptured by pressure or shear force and reacts with the epoxy groups in the matrix to form a crosslinked network.

[0016] Preferably, the functionalized fiber reinforced material comprises the following components: polyvinyl alcohol fiber, polypropylene fiber and basalt fiber, and their weight ratio is (0.5 - 1):(0.3 - 0.7):(0.2 - 0.5), and the fiber length is 3 - 12 mm.

[0017] Preferably, the two-component nano-modified manufactured sand is prepared by the following steps: N1. Soak the manufactured sand in a sodium hydroxide solution with a mass concentration of 5 - 10% for 2 - 4 hours, filter, wash with water, and dry to obtain alkali-treated manufactured sand; N2. Mix γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane in a weight ratio of 1:(1 - 3), add methanol to dilute to a total solid content of 3 - 5%, adjust the pH to 4 - 5, and hydrolyze for 2 - 4 hours to obtain a silane coupling agent solution; N3. Add the alkali-treated manufactured sand to the silane coupling agent solution, with a liquid-solid ratio of (2 - 3):1, stir at room temperature for 4 - 6 hours, filter, and dry at 60 - 80°C for 3 - 5 hours to obtain the first-component modified sand; N4. Disperse amino-modified nano-silica and amino-modified graphene in ethanol in a weight ratio of (8 - 12):(0.5 - 1.5), and perform ultrasonic treatment for 1 - 2 hours to obtain a nano-material dispersion; N5. Add the first-component modified sand to the nano-material dispersion, with a liquid-solid ratio of (1.5 - 2.5):1, stir at room temperature for 2 - 4 hours, filter, and dry at 60 - 80°C for 3 - 5 hours to obtain the two-component nano-modified manufactured sand.

[0018] Preferably, the manufactured sand is one or a mixture of several of river sand, limestone manufactured sand, basalt manufactured sand or granite manufactured sand, wherein the fineness modulus of the sand is 2.3 - 3.5 and the stone powder content is 2 - 8%.

[0019] Preferably, the silicone-modified polyether end-capping agent is prepared by reacting polydimethylsiloxane with polyether at a weight ratio of 1:(2-4) at 110-130 °C for 3-5 hours under the action of a catalyst.

[0020] Preferably, the multifunctional composite catalyst system comprises the following components: an organic amine catalyst, an organic peroxide, and a metal chelate, and their weight ratio is (0.2-0.4):(0.1-0.3):(0.2-0.5).

[0021] In addition, the present application also provides a preparation method of the above anti-seepage repair material, comprising the following steps: B1. Under nitrogen protection, mix nano-modified polyurethane acrylate, bio-based modified acrylate, and modified lignin, heat up to 60-70 °C, and stir for 20-30 minutes; B2. Heat up to 130-150 °C, add environmentally friendly asphalt, and stir for 15-25 minutes; B3. Cool down to 50-60 °C, add the silicone-modified polyether end-capping agent, stir for 10-20 minutes, and cool to room temperature to obtain a matrix material; B4. Thoroughly mix high-performance portland cement, an expansive inorganic mineral combination, and two-component nano-modified manufactured sand for 2-4 minutes to obtain a solid component; B5. Mix the solid component with the matrix material, add a microcapsule self-healing component, stir at a low speed at 35-45 °C for 2-3 minutes, then add a functionalized fiber reinforcing material and a multifunctional composite catalyst system, stir for 3-5 minutes, and finally perform ultrasonic treatment for 1-2 minutes to promote uniform dispersion of the components, thus obtaining the anti-seepage repair material.

[0022] Compared with the prior art, the beneficial effects of the present application are as follows: By introducing nano-modification, bio-based modification, self-healing microcapsules, and two-component modified manufactured sand, the present application realizes the organic unity of high strength, environmental friendliness, self-healing property, and excellent anti-seepage performance of the material. Detailed embodiments

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0024] In a broad embodiment of the present application, a waterproof and seepage repair material for building expansion joints, by weight, the waterproof and seepage repair material comprises the following components: 8-12 parts of nano-modified polyurethane acrylate; 5-8 parts of bio-based modified acrylate; 3-6 parts of modified lignin; 4-7 parts of environmentally friendly asphalt; 4-7 parts of high-performance portland cement; 8-12 parts of expansive inorganic mineral combination; 1-2 parts of microcapsule self-healing component; 1-3 parts of functionalized fiber reinforcement; 55-65 parts of two-component nano-modified manufactured sand; 0.8-1.2 parts of organosilicon-modified polyether end-capping agent; 0.5-1.5 parts of multifunctional composite catalyst system.

[0025] Preferably, the nano-modified polyurethane acrylate is prepared by the following steps: heating the polyurethane acrylate to 60-70 °C, adding 1-3% by weight of amino-modified nano-silica particles thereto under stirring conditions, continuing to heat up to 80-90 °C, stirring and reacting for 2-4 hours, and then cooling to room temperature to obtain.

[0026] Preferably, the general formula structure of the nano-modified polyurethane acrylate is represented as: PU-(CH2CHCOO) n +SiO2-NH2, where: PU is a polyester-type or polyether-type polyurethane chain segment; n = 2-5.

[0027] Preferably, the bio-based modified acrylate is prepared by the following steps: adding 15-25% by weight of soybean oil fatty acid derivatives and 5-10% by weight of hempseed oil fatty acid esters to the polyacrylate, and stirring and reacting at 70-80 °C for 3-5 hours under nitrogen protection to obtain.

[0028] Preferably, the general formula of the bio-based modified acrylate is: PAA-[COOCH2(CH=CH) x R] m , where PAA is the polyacrylate main chain; x = 1-2; R is a natural fatty acid group; m is the degree of substitution, m = 0.15-0.35.

[0029] Preferably, the modified lignin is obtained by mixing lignin and maleic anhydride in a weight ratio of 3:1-5:1, carrying out an esterification reaction at 150-170 °C for 2-3 hours, and then carrying out a ring-opening reaction with epoxy resin in a weight ratio of 2:1-4:1 for 1-2 hours.

[0030] Preferably, the general formula structure of the modified lignin is: Lignin-OCOCH=CHCOO-[CH2CH(OH)CH2] p , where: Lignin is a lignin group; p represents the length of the epoxy chain segment, p = 1–4.

[0031] Preferably, the environment-friendly asphalt is prepared by mixing biomass pyrolysis oil and petroleum asphalt in a weight ratio of 3:7 - 5:5 and adding 1 - 3% of SBS modifier.

[0032] Preferably, the expandable inorganic mineral combination includes the following components: expanded perlite powder, bentonite, silica fume, and magnesium oxide, and their weight ratio is (3 - 5):(2 - 4):(2 - 3):(1 - 2).

[0033] Preferably, the microcapsule self-healing component is an epoxy resin curing agent encapsulated by polyurea microcapsules. The diameter of the microcapsules is 50 - 200 μm, and the wall thickness is 2 - 5 μm. When the microcapsules are ruptured under pressure or shear force, the curing agent is released and reacts with the epoxy groups in the matrix to form a crosslinked network.

[0034] Preferably, the functionalized fiber-reinforced material includes the following components: polyvinyl alcohol fiber, polypropylene fiber, and basalt fiber, and their weight ratio is (0.5 - 1):(0.3 - 0.7):(0.2 - 0.5), and the fiber length is 3 - 12 mm.

[0035] Preferably, the two-component nano-modified manufactured sand is prepared by the following steps: N1. Soak the manufactured sand in a sodium hydroxide solution with a mass concentration of 5 - 10% for 2 - 4 hours, filter, wash with water, and dry to obtain alkali-treated manufactured sand; N2. Mix γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane in a weight ratio of 1:(1 - 3), add methanol to dilute to a total solid content of 3 - 5%, adjust the pH to 4 - 5, and hydrolyze for 2 - 4 hours to obtain a silane coupling agent solution; N3. Add the alkali-treated manufactured sand to the silane coupling agent solution, with a liquid-solid ratio of (2 - 3):1, stir at room temperature for 4 - 6 hours, filter, and dry at 60 - 80°C for 3 - 5 hours to obtain the first-component modified sand; N4. Disperse amino-modified nano-silica and amino-modified graphene in a weight ratio of (8 - 12):(0.5 - 1.5) in ethanol and perform ultrasonic treatment for 1 - 2 hours to obtain a nano-material dispersion; N5. Add the first-component modified sand to the nano-material dispersion, with a liquid-solid ratio of (1.5 - 2.5):1, stir at room temperature for 2 - 4 hours, filter, and dry at 60 - 80°C for 3 - 5 hours to obtain the two-component nano-modified manufactured sand.

[0036] Preferably, the manufactured sand is one or a mixture of river sand, limestone manufactured sand, basalt manufactured sand, or granite manufactured sand, where the fineness modulus of the sand is 2.3 - 3.5 and the stone powder content is 2 - 8%.

[0037] Preferably, the organosilicon-modified polyether capping agent is prepared by reacting polydimethylsiloxane and polyether in a weight ratio of 1:(2 - 4) at 110 - 130°C for 3 - 5 hours under the action of a catalyst.

[0038] Preferably, the multifunctional composite catalyst system comprises the following components: an organic amine catalyst, an organic peroxide, and a metal chelate, and their weight ratio is (0.2 - 0.4):(0.1 - 0.3):(0.2 - 0.5).

[0039] In addition, the present application also provides a preparation method of the above anti-seepage repair material, comprising the following steps: B1. Under nitrogen protection, mix nano-modified polyurethane acrylate, bio-based modified acrylate, and modified lignin, heat up to 60 - 70 °C, and stir for 20 - 30 minutes; B2. Heat up to 130 - 150 °C, add environmentally friendly asphalt, and stir for 15 - 25 minutes; B3. Cool down to 50 - 60 °C, add an organosilicon-modified polyether end-capping agent, stir for 10 - 20 minutes, and cool to room temperature to obtain a matrix material; B4. Thoroughly mix high-performance portland cement, an expansive inorganic mineral combination, and two-component nano-modified manufactured sand for 2 - 4 minutes to obtain a solid component; B5. Mix the solid component with the matrix material, add a microcapsule self-healing component, stir at a low speed at 35 - 45 °C for 2 - 3 minutes, then add a functionalized fiber reinforcing material and a multifunctional composite catalyst system, stir for 3 - 5 minutes, and finally perform ultrasonic treatment for 1 - 2 minutes to promote the uniform dispersion of the components, thus obtaining the anti-seepage repair material.

[0040] The following list the Examples 1 - 3 of the present application for further detailed description of the present application.

[0041] Example 1.

[0042] In this example, by weight, the anti-seepage repair material comprises the following components: 10 parts of nano-modified polyurethane acrylate; 6 parts of bio-based modified acrylate; 4 parts of modified lignin; 5 parts of environmentally friendly asphalt; 5 parts of high-performance portland cement; 10 parts of an expansive inorganic mineral combination; 1.5 parts of a microcapsule self-healing component; 2 parts of a functionalized fiber reinforcing material; 60 parts of two-component nano-modified manufactured sand; 1 part of an organosilicon-modified polyether end-capping agent; 1 part of a multifunctional composite catalyst system.

[0043] In this example, the nano-modified polyurethane acrylate is prepared by the following method: Heat the polyurethane acrylate to 65 °C, add 2% by weight of amino-modified nano-silica particles under stirring conditions, continue to heat up to 85 °C, stir and react for 3 hours, and then cool to room temperature to obtain it.

[0044] In this example, the bio-based modified acrylate is prepared by the following method: Add 20% by weight of soybean oil fatty acid derivatives and 7% by weight of hemp seed oil fatty acid esters to polyacrylate, and under nitrogen protection, stir and react at 75 °C for 4 hours to obtain it.

[0045] In this embodiment, the modified lignin is prepared by the following method: lignin and maleic anhydride are mixed at a weight ratio of 4:1, and an esterification reaction is carried out at 160 °C for 2.5 hours, and then a ring-opening reaction is carried out with epoxy resin at a weight ratio of 3:1 for 1.5 hours to obtain it.

[0046] In this embodiment, the environment-friendly asphalt is prepared by the following method: biomass pyrolysis oil and petroleum asphalt are mixed at a weight ratio of 4:6, and 2% of SBS modifier is added and stirred and mixed at 170 °C for 1 hour.

[0047] In this embodiment, the expandable inorganic mineral combination includes the following components: expanded perlite powder, bentonite, silica fume and magnesium oxide, and their weight ratio is 4:3:2.5:1.5.

[0048] In this embodiment, the microcapsule self-healing component is an epoxy resin curing agent wrapped by polyurea microcapsules. The diameter of the microcapsules is 100 μm, and the wall thickness is 3 μm. When the microcapsules are ruptured under pressure or shear force, the curing agent is released and reacts with the epoxy groups in the matrix to form a crosslinked network. The microcapsules are prepared by the interfacial polymerization method. The specific method is as follows: 4 parts of epoxy resin curing agent (polyetheramine) are dissolved in 6 parts of cyclohexane to form an organic phase; 2 parts of polyisocyanate prepolymer are dissolved in 10 parts of ethyl acetate; the organic phase is dispersed in an aqueous solution containing 1% polyvinyl alcohol to form an O / W emulsion; the polyisocyanate prepolymer solution is added dropwise with stirring at 30 °C, and the reaction is carried out for 3 hours to form a polyurea wall layer; filtration, washing with water, and vacuum drying are carried out to obtain the microcapsule self-healing component.

[0049] In this embodiment, the functionalized fiber-reinforced material includes the following components: polyvinyl alcohol fiber, polypropylene fiber and basalt fiber, and their weight ratio is 0.8:0.5:0.7, and the fiber length is 6 mm.

[0050] In this embodiment, the two-component nano-modified machine-made sand is prepared by the following steps: (1) soaking river sand (fineness modulus of 2.8, stone powder content of 5%) in a sodium hydroxide solution with a mass concentration of 8% for 3 hours, filtering, washing with water until neutral, and drying at 70° C. to obtain alkali-treated machine-made sand; (2) mixing γ-glycidyloxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane in a weight ratio of 1:2, adding methanol to dilute to a total solid content of 4%, adjusting the pH to 4.5, and hydrolyzing for 3 hours to obtain a silane coupling agent solution; (3 ) Add the alkali-treated machine-made sand to the silane coupling agent solution at a liquid-to-solid ratio of 2.5:1, stir at room temperature for 5 hours, filter, and dry at 70°C for 4 hours to obtain the first component modified sand; (4) Disperse the amino-modified nano-silica and amino-modified graphene in ethanol at a weight ratio of 10:1, and ultrasonically treat for 1.5 hours to obtain a nanomaterial dispersion; (5) Add the first component modified sand to the nanomaterial dispersion at a liquid-to-solid ratio of 2:1, stir at room temperature for 3 hours, filter, and dry at 70°C for 4 hours to obtain a two-component nano-modified machine-made sand.

[0051] In this embodiment, the organosilicon-modified polyether end-capping agent is prepared by the following method: polydimethylsiloxane and polyether are reacted at a weight ratio of 1:3 at 120° C. for 4 hours in the presence of a dibutyltin dilaurate catalyst (accounting for 0.5% of the total weight).

[0052] In this embodiment, the multifunctional composite catalyst system includes the following components: dimethylbenzylamine (organic amine catalyst), benzoyl peroxide (organic peroxide) and zinc acetylacetonate (metal chelate), and the weight ratio thereof is 0.3:0.2:0.5.

[0053] In this embodiment, the preparation method of the anti-seepage repair material includes the following steps: (1) under nitrogen protection, nano-modified polyurethane acrylate, bio-based modified acrylate, and modified lignin are mixed, heated to 65°C, and stirred for 25 minutes; (2) heated to 140°C, environmentally friendly asphalt is added, and stirred for 20 minutes; (3) cooled to 55°C, silicone-modified polyether capping agent is added, stirred for 15 minutes, and cooled to room temperature to obtain a matrix material; (4) high-performance silicate cement, expansive inorganic mineral combination, and two-component nano-modified machine-made sand are fully mixed for 3 minutes to obtain a solid component; (5) the solid component is mixed with the matrix material, a microcapsule self-repairing component is added, and the mixture is stirred at a low speed at 40°C for 2.5 minutes, and then a functionalized fiber reinforcement material and a multifunctional composite catalyst system are added, stirred for 4 minutes, and finally ultrasonically treated for 1.5 minutes to promote uniform dispersion of the components, thereby obtaining an anti-seepage repair material.

[0054] Example 2.

[0055] In this embodiment, by weight, the anti-seepage repair material comprises the following components: 12 parts of nano-modified polyurethane acrylate; 8 parts of bio-based modified acrylate; 6 parts of modified lignin; 7 parts of environment-friendly asphalt; 7 parts of high-performance portland cement; 12 parts of expansive inorganic mineral combination; 2 parts of microcapsule self-healing component; 3 parts of functionalized fiber reinforcing material; 65 parts of two-component nano-modified manufactured sand; 1.2 parts of organosilicon-modified polyether capping agent; 1.5 parts of multi-functional composite catalyst system.

[0056] In this embodiment, the nano-modified polyurethane acrylate is prepared by the following method: Heat the polyurethane acrylate to 70 °C, add 3% by weight of amino-modified nano-silica particles under stirring conditions, continue to heat up to 90 °C, stir and react for 4 hours, and then cool to room temperature to obtain.

[0057] In this embodiment, the bio-based modified acrylate is prepared by the following method: Add 25% by weight of soybean oil fatty acid derivative and 10% by weight of hemp seed oil fatty acid ester to the polyacrylate, and under nitrogen protection, stir and react at 80 °C for 5 hours to obtain.

[0058] In this embodiment, the modified lignin is prepared by the following method: Mix lignin and maleic anhydride in a weight ratio of 5:1, carry out esterification reaction at 170 °C for 3 hours, and then carry out ring-opening reaction with epoxy resin in a weight ratio of 4:1 for 2 hours to obtain.

[0059] In this embodiment, the environment-friendly asphalt is prepared by the following method: Mix biomass pyrolysis oil and petroleum asphalt in a weight ratio of 5:5, and add 3% of SBS modifier, and stir and mix at 180 °C for 1.5 hours to prepare.

[0060] In this embodiment, the expansive inorganic mineral combination comprises the following components: expanded perlite powder, bentonite, silica fume and magnesium oxide, and their weight ratio is 5:4:3:2.

[0061] In this embodiment, the microcapsule self-healing component is an epoxy resin curing agent encapsulated by polyurea microcapsules. The diameter of the microcapsules is 150 μm, and the wall thickness is 4 μm. When the microcapsules are ruptured under pressure or shear force, the curing agent is released and reacts with the epoxy groups in the matrix to form a cross-linked network. The microcapsules are prepared by the interfacial polymerization method. The specific method is as follows: Dissolve 5 parts of epoxy resin curing agent (aromatic amine) in 7 parts of cyclohexane to form an organic phase; dissolve 3 parts of polyisocyanate prepolymer in 12 parts of ethyl acetate; disperse the organic phase in an aqueous solution containing 1.5% polyvinyl alcohol to form an O / W emulsion; dropwise add the polyisocyanate prepolymer solution under stirring at 35 °C, and react for 4 hours to form a polyurea wall layer; filter, wash with water, and vacuum dry to obtain the microcapsule self-healing component.

[0062] In this embodiment, the functionalized fiber-reinforced material comprises the following components: polyvinyl alcohol fiber, polypropylene fiber, and basalt fiber, with a weight ratio of 1:0.7:1.3, and the fiber length is 9 mm.

[0063] In this embodiment, the two-component nano-modified manufactured sand is prepared by the following steps: (1) Immerse basalt manufactured sand (fineness modulus is 3.0, stone powder content is 6%) in a sodium hydroxide solution with a mass concentration of 10% for 4 hours, filter, wash with water until neutral, and dry at 80 °C to obtain alkali-treated manufactured sand; (2) Mix γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane in a weight ratio of 1:3, add methanol to dilute to a total solid content of 5%, adjust the pH to 4, and hydrolyze for 4 hours to obtain a silane coupling agent solution; (3) Add the alkali-treated manufactured sand to the silane coupling agent solution, with a liquid-solid ratio of 3:1, stir at room temperature for 6 hours, filter, and dry at 80 °C for 5 hours to obtain the first-component modified sand; (4) Disperse amino-modified nano-silica and amino-modified graphene in ethanol in a weight ratio of 12:1.5, and ultrasonically treat for 2 hours to obtain a nano-material dispersion; (5) Add the first-component modified sand to the nano-material dispersion, with a liquid-solid ratio of 2.5:1, stir at room temperature for 4 hours, filter, and dry at 80 °C for 5 hours to obtain the two-component nano-modified manufactured sand.

[0064] In this embodiment, the organosilicon-modified polyether end-capping agent is prepared by the following method: React polydimethylsiloxane and polyether in a weight ratio of 1:4 at 130 °C for 5 hours under the action of a dibutyltin dilaurate catalyst (accounting for 0.8% of the total weight).

[0065] In this embodiment, the multifunctional composite catalyst system comprises the following components: triethylamine (organic amine catalyst), dibenzoyl peroxide (organic peroxide), and copper acetylacetonate (metal chelate), with a weight ratio of 0.4:0.3:0.8.

[0066] In this embodiment, the preparation method of the anti-seepage repair material comprises the following steps: (1) Under nitrogen protection, mix nano-modified polyurethane acrylate, bio-based modified acrylate, and modified lignin, heat up to 70 °C, and stir for 30 minutes; (2) Heat up to 150 °C, add environment-friendly asphalt, and stir for 25 minutes; (3) Cool down to 60 °C, add organosilicon-modified polyether end-capping agent, stir for 20 minutes, and cool to room temperature to obtain the matrix material; (4) Thoroughly mix high-performance portland cement, expansive inorganic mineral combination, and two-component nano-modified manufactured sand for 4 minutes to obtain the solid component; (5) Mix the solid component with the matrix material, add the microcapsule self-healing component, stir at a low speed at 45 °C for 3 minutes, then add the functionalized fiber reinforcing material and the multi-functional composite catalyst system, stir for 5 minutes, and finally perform ultrasonic treatment for 2 minutes to promote the uniform dispersion of the components, thus obtaining the anti-seepage repair material.

[0067] Example 3.

[0068] In this embodiment, by weight, the anti-seepage repair material comprises the following components: 8 parts of nano-modified polyurethane acrylate; 5 parts of bio-based modified acrylate; 3 parts of modified lignin; 4 parts of environment-friendly asphalt; 4 parts of high-performance portland cement; 8 parts of expansive inorganic mineral combination; 1 part of microcapsule self-healing component; 1 part of functionalized fiber reinforcing material; 55 parts of two-component nano-modified manufactured sand; 0.8 part of organosilicon-modified polyether end-capping agent; 0.5 part of multi-functional composite catalyst system.

[0069] In this embodiment, the nano-modified polyurethane acrylate is prepared by the following method: Heat the polyurethane acrylate to 60 °C, add 1% by weight of amino-modified nano-silica particles under stirring conditions, continue to heat up to 80 °C, stir and react for 2 hours, and then cool to room temperature to obtain it.

[0070] In this embodiment, the bio-based modified acrylate is prepared by the following method: Add 15% by weight of soybean oil fatty acid derivative and 5% by weight of hemp seed oil fatty acid ester to the polyacrylate, and stir and react at 70 °C for 3 hours under nitrogen protection to obtain it.

[0071] In this embodiment, the modified lignin is prepared by the following method: Mix lignin and maleic anhydride in a weight ratio of 3:1, carry out an esterification reaction at 150 °C for 2 hours, and then carry out a ring-opening reaction with epoxy resin in a weight ratio of 2:1 for 1 hour to obtain it.

[0072] In this embodiment, the environment-friendly asphalt is prepared by the following method: Mix biomass pyrolysis oil and petroleum asphalt in a weight ratio of 3:7, and add 1% of SBS modifier, and stir and mix at 160 °C for 0.5 hour to prepare it.

[0073] In this embodiment, the expansive inorganic mineral combination includes the following components: expanded perlite powder, bentonite, silica fume, and magnesium oxide, and their weight ratio is 3:2:2:1.

[0074] In this embodiment, the microcapsule self-healing component is an epoxy resin curing agent encapsulated by polyurea microcapsules. The microcapsules have a diameter of 50 μm and a wall thickness of 2 μm. When the microcapsules are ruptured under pressure or shear force, the curing agent is released and reacts with the epoxy groups in the matrix to form a crosslinked network. The microcapsules are prepared by the interfacial polymerization method. The specific method is as follows: Dissolve 3 parts of epoxy resin curing agent (fatty amine) in 5 parts of cyclohexane to form an organic phase; dissolve 1 part of polyisocyanate prepolymer in 8 parts of ethyl acetate; disperse the organic phase in an aqueous solution containing 0.8% polyvinyl alcohol to form an O / W emulsion; dropwise add the polyisocyanate prepolymer solution with stirring at 25°C and react for 2 hours to form a polyurea wall layer; filter, wash with water, and dry in vacuum to obtain the microcapsule self-healing component.

[0075] In this embodiment, the functionalized fiber-reinforced material includes the following components: polyvinyl alcohol fiber, polypropylene fiber, and basalt fiber, and their weight ratio is 0.5:0.3:0.2, and the fiber length is 3 mm.

[0076] In this embodiment, the two-component nano-modified manufactured sand is prepared by the following steps: (1) Immerse granite manufactured sand (with a fineness modulus of 2.5 and a stone powder content of 3%) in a sodium hydroxide solution with a mass concentration of 5% for 2 hours, filter, wash with water until neutral, and dry at 60°C to obtain alkali-treated manufactured sand; (2) Mix γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane in a weight ratio of 1:1, add methanol to dilute to a total solid content of 3%, adjust the pH to 5, and hydrolyze for 2 hours to obtain a silane coupling agent solution; (3) Add the alkali-treated manufactured sand to the silane coupling agent solution, with a liquid-solid ratio of 2:1, stir at room temperature for 4 hours, filter, and dry at 60°C for 3 hours to obtain the first-component modified sand; (4) Disperse amino-modified nano-silica and amino-modified graphene in ethanol in a weight ratio of 8:0.5 and ultrasonically treat for 1 hour to obtain a nano-material dispersion; (5) Add the first-component modified sand to the nano-material dispersion, with a liquid-solid ratio of 1.5:1, stir at room temperature for 2 hours, filter, and dry at 60°C for 3 hours to obtain the two-component nano-modified manufactured sand.

[0077] In this embodiment, the organosilicon-modified polyether end-capping agent is prepared by the following method: React polydimethylsiloxane and polyether in a weight ratio of 1:2 at 110°C for 3 hours under the action of dibutyltin dilaurate catalyst (accounting for 0.3% of the total weight).

[0078] In this embodiment, the multifunctional composite catalyst system comprises the following components: N,N-dimethylbenzylamine (organic amine catalyst), tert-butyl hydroperoxide (organic peroxide), and magnesium acetylacetonate (metal chelate), with a weight ratio of 0.2:0.1:0.2.

[0079] In this embodiment, the preparation method of the anti-seepage repair material comprises the following steps: (1) Under nitrogen protection, mix nano-modified polyurethane acrylate, bio-based modified acrylate, and modified lignin, heat up to 60°C, and stir for 20 minutes; (2) Heat up to 130°C, add environmentally friendly asphalt, and stir for 15 minutes; (3) Cool down to 50°C, add organosilicon-modified polyether end-capping agent, and stir for 10 minutes, then cool to room temperature to obtain the matrix material; (4) Thoroughly mix high-performance portland cement, expansive inorganic mineral combination, and two-component nano-modified manufactured sand for 2 minutes to obtain the solid component; (5) Mix the solid component with the matrix material, add the microcapsule self-healing component, stir at a low speed at 35°C for 2 minutes, then add the functionalized fiber reinforcing material and the multifunctional composite catalyst system, stir for 3 minutes, and finally perform ultrasonic treatment for 1 minute to promote uniform dispersion of the components, thus obtaining the anti-seepage repair material.

[0080] The anti-seepage repair materials prepared in Examples 1-3 were subjected to performance tests. The test results were as follows: the compressive strength of Example 1 was 45.6 MPa, the tensile strength was 4.2 MPa, the bonding strength was 3.8 MPa, the water impermeability was greater than 72 hours, the elongation rate was 135%, the weather resistance was 300 cycle times, the freeze-thaw resistance was 150 cycle times, and the self-healing efficiency was 76%; the compressive strength of Example 2 was 52.3 MPa, the tensile strength was 5.1 MPa, the bonding strength was 4.5 MPa, the water impermeability was greater than 96 hours, the elongation rate was 150%, the weather resistance was 350 cycle times, the freeze-thaw resistance was 180 cycle times, and the self-healing efficiency was 85%; the compressive strength of Example 3 was 38.5 MPa, the tensile strength was 3.6 MPa, the bonding strength was 3.2 MPa, the water impermeability was greater than 48 hours, the elongation rate was 120%, the weather resistance was 250 cycle times, the freeze-thaw resistance was 120 cycle times, and the self-healing efficiency was 68%.

[0081] The above performance indicators were measured by the following test methods respectively: the compressive strength and tensile strength were measured by the GB / T 17671 test method, the bonding strength was measured by the JC / T 2438 test method, the water impermeability and freeze-thaw resistance were measured by the GB / T 50082 test method, the elongation rate was measured by the GB / T 328.8 test method, and the weather resistance was measured by the GB / T 16777 test method. The self-healing efficiency was determined by the recovery rate of the tensile strength before and after repair.

[0082] Self-healing efficiency test method: Stretch the sample until microcracks appear (width about 100 μm), then place it in a standard environment (temperature 23 ± 2 °C, relative humidity 50 ± 5%) for 7 days, and conduct the tensile strength test again. The self-healing efficiency is expressed as the percentage of the strength after repair to the original strength.

[0083] As can be seen from the above test results, the anti-seepage repair material prepared in this application has excellent mechanical properties, waterproof properties and durability. In particular, by introducing the microcapsule self-healing component, the material can self-repair after being damaged, significantly extending the service life. In Example 2, due to the addition of a relatively large amount of microcapsule self-healing component (2 parts) and a relatively high proportion of linseed oil fatty acid ester (10%), the best self-healing efficiency (85%) and mechanical properties are shown.

[0084] Apply the anti-seepage repair material prepared in Example 1 to the expansion joint anti-seepage repair project of the underground garage of a large commercial complex. The total length of the expansion joint in this project is about 120 meters, the width is 40 - 60 mm, the maximum displacement is ±20 mm, and there is obvious water seepage. The construction steps are as follows: (1) Clean the expansion joint: Use a high-pressure water gun and an industrial vacuum cleaner to thoroughly clean the sundries and dust in the expansion joint; (2) Drying treatment: Use a hot air gun to dry the expansion joint; (3) Primer treatment: Apply an epoxy resin primer on the surface of the expansion joint to enhance the adhesion between the material and the substrate; (4) Fill the anti-seepage material: Fill the anti-seepage repair material prepared in this application into the expansion joint and compact it with a special tool; (5) Surface treatment: Use a trowel to level the surface and spray a protective layer.

[0085] After the construction was completed, the repair effect was tracked and observed. After experiencing a rainy season (including 3 heavy rains), no leakage occurred at the repaired part. In the artificial loading test, the expansion joint can expand and contract normally, and the anti-seepage repair material did not show fracture or peeling. After 9 months of use, the repaired part still maintained good anti-seepage effect and mechanical properties.

[0086] As can be seen from the above examples, the building expansion joint anti-seepage repair material provided in this application, by introducing the microcapsule self-healing component, expanding the source of bio-based materials, and optimizing the preparation process, has excellent anti-seepage performance, ductility performance and self-healing ability, can effectively solve the leakage problem of building expansion joints, and extend the service life of the repair material.

[0087] In the above Examples 1-3, the polyurethane acrylate used was purchased from Guangdong Boxin New Materials Technology Co., Ltd. (model B-369), the amino-modified nano-silica particles were amino-silica microspheres produced by Nanjing Jike Biotechnology Co., Ltd., the polyacrylate was polyacrylate emulsion produced by Beijing Dechang Weiye Construction Engineering Technology Co., Ltd., the soybean oil fatty acid derivative was soybean oil fatty acid produced by Shandong Xin County Lishengyuan New Energy Co., Ltd., and the hemp seed oil fatty acid ester was produced by Hebei Xinqidian Biotechnology Co., Ltd. Lignin was produced by Tianjin Deqian Lignin Technology Co., Ltd., maleic anhydride was from Zibo Lishuo Chemical Industry Co., Ltd., the epoxy resin used was NPES-901 resin produced by South Asia (Kunshan) Co., Ltd., and the biomass pyrolysis oil was purchased from Zhengzhou Huilv Technology Co., Ltd. The petroleum asphalt was "Beili Brand" petroleum asphalt (model AH-90) produced by Panjin Northern Asphalt Fuel Co., Ltd., the SBS modifier was provided by Huizhou Lee Chang Yung Chemical Co., Ltd. (model 3501F), the expanded perlite powder was produced by Zibo Zhangdian Pengyue Thermal Insulation Materials Factory, the bentonite was JF-27 type bentonite produced by Zhejiang Fenghong New Materials Co., Ltd., the silica fume was concrete silica fume produced by Shijiazhuang Tourmaline Mineral Products Co., Ltd., and the magnesium oxide was 8161 type high-purity magnesium oxide produced by Weifang Wanfeng New Materials Technology Co., Ltd. The epoxy resin curing agent was produced by Changzhou Shanfeng Chemical Co., Ltd., cyclohexane was produced by Shandong Yuhuang Chemical Group Co., Ltd., the ethyl acetate was industrial ethyl acetate produced by Shandong Jinyimeng Group Co., Ltd., the polyisocyanate prepolymer was produced by Zibo Yahuaxin Rubber and Plastic Co., Ltd. Polyvinyl alcohol was produced by Anhui Wanwei High-Tech Materials Co., Ltd., polyvinyl alcohol fiber was produced by Jiangxi Xiancai New Materials Technology Co., Ltd., polypropylene fiber was produced by Jiangsu Bote New Materials Co., Ltd., and basalt fiber was produced by Sichuan Aerospace Tuoxin Basalt Industry Co., Ltd. The river sand was construction-grade river sand provided by local building material suppliers, sodium hydroxide was produced by China National Chemical Corporation, γ-glycidoxypropyltrimethoxysilane was produced by Nanjing Daoning Chemical Co., Ltd., and 3-aminopropyltrimethoxysilane was produced by Hangzhou Guibao Chemical Co., Ltd. Methanol and ethanol were both analytical-grade methanol and ethanol produced by Fuchen (Tianjin) Chemical Reagent Co., Ltd., amino-modified graphene was purchased from Changzhou Sixth Element Materials Technology Co., Ltd., polydimethylsiloxane was produced by Xin'an Chemical Industry Group Co., Ltd., polyurea microcapsules were produced by Shandong Lianchuang New Materials Industry Co., Ltd., and polyether was produced by Shanghai Gaqiao Petrochemical Co., Ltd. The dibutyltin dilaurate catalyst was produced by Jinan Jinhao Chemical Co., Ltd., dimethylbenzylamine was produced by Jiangsu Qiangsheng Functional Chemical Co., Ltd., benzoyl peroxide was provided by Jiangsu Qiangsheng Functional Chemical Co., Ltd., zinc acetylacetonate was produced by Zibo Huaxing Auxiliary Co., Ltd., and the high-performance portland cement was p.o42.5 cement produced by Anhui Conch Cement Co., Ltd.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An anti-seepage repair material for building expansion joints, characterized in that, By weight parts, the anti-seepage repair material comprises the following components: 8-12 parts of nano-modified polyurethane acrylate; 5-8 parts of bio-based modified acrylate; 3-6 parts of modified lignin; 4-7 parts of environment-friendly asphalt; 4-7 parts of high-performance portland cement; 8-12 parts of expansive inorganic mineral combination; 1-2 parts of microcapsule self-healing component; 1-3 parts of functionalized fiber reinforcing material; 55-65 parts of two-component nano-modified manufactured sand; 0.8-1.2 parts of organosilicon-modified polyether end-capping agent; 0.5-1.5 parts of multi-functional composite catalyst system.

2. The anti-seepage repair material for building expansion joints according to claim 1, wherein, The nano-modified polyurethane acrylate is prepared by the following steps: heating polyurethane acrylate to 60-70 °C, adding amino-modified nano-silica particles accounting for 1-3% of its weight under stirring conditions, continuously heating to 80-90 °C, stirring and reacting for 2-4 hours, and then cooling to room temperature to obtain; The bio-based modified acrylate is prepared by the following steps: adding soybean oil fatty acid derivative accounting for 15-25% of its weight and hemp seed oil fatty acid ester accounting for 5-10% of its weight to polyacrylate, and stirring and reacting at 70-80 °C for 3-5 hours under nitrogen protection to obtain; The modified lignin is obtained by mixing lignin and maleic anhydride in a weight ratio of 3:1-5:1, carrying out esterification reaction at 150-170 °C for 2-3 hours, and then carrying out ring-opening reaction with epoxy resin in a weight ratio of 2:1-4:1 for 1-2 hours.

3. The anti-seepage repair material for building expansion joints according to claim 2, characterized in that, The general formula structure of the nano-modified polyurethane acrylate is expressed as: PU-(CH2CHCOO) n +SiO2-NH2, where: PU is a polyester-type or polyether-type polyurethane segment; n = 2-5; The general formula of the bio-based modified acrylate is: PAA-[COOCH2(CH=CH) x R] m , where PAA is the polyacrylate main chain; x = 1 - 2; R is a natural fatty acid group; m is the degree of substitution, m = 0.15 - 0.35; The general formula structure of the modified lignin is: Lignin-OCOCH=CHCOO-[CH2CH(OH)CH2] p , where: Lignin is a lignin group; p represents the length of the epoxy chain segment, and p = 1–4.

4. The anti-seepage repair material for building expansion joints according to claim 1, wherein The environment-friendly asphalt is prepared by mixing biomass pyrolysis oil and petroleum asphalt in a weight ratio of 3:7-5:5 and adding 1-3% of SBS modifier; The expansive inorganic mineral combination comprises the following components: expanded perlite powder, bentonite, silica fume and magnesium oxide, and their weight ratio is (3-5):(2-4):(2-3):(1-2); The microcapsule self-healing component is an epoxy resin curing agent encapsulated by polyurea microcapsules, the diameter of the microcapsules is 50-200 μm, the wall thickness is 2-5 μm, and the curing agent is released when the microcapsules are ruptured by pressure or shear force and reacts with epoxy groups in the matrix to form a cross-linked network.

5. An anti-seepage repair material for building expansion joints according to claim 1, characterized in that, The functionalized fiber reinforcing material comprises the following components: polyvinyl alcohol fiber, polypropylene fiber and basalt fiber, and their weight ratio is (0.5-1):(0.3-0.7):(0.2-0.5), and the fiber length is 3-12 mm.

6. An anti-seepage repair material for building expansion joints according to claim 1, characterized in that, The two-component nano-modified manufactured sand is prepared by the following steps: N1. Soaking the manufactured sand in a sodium hydroxide solution with a mass concentration of 5-10% for 2-4 hours, filtering, washing with water, and drying to obtain alkali-treated manufactured sand; N2. Mixing γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane in a weight ratio of 1:(1-3), adding methanol to dilute to a total solid content of 3-5%, adjusting the pH to 4-5, and hydrolyzing for 2-4 hours to obtain a silane coupling agent solution; N3. Adding the alkali-treated manufactured sand to the silane coupling agent solution, with a liquid-solid ratio of (2-3):1, stirring and treating at room temperature for 4-6 hours, filtering, and drying at 60-80 °C for 3-5 hours to obtain the first-component modified sand; N4. Disperse amino-modified nano-silica and amino-modified graphene in ethanol at a weight ratio of (8 - 12):(0.5 - 1.5), and perform ultrasonic treatment for 1 - 2 hours to obtain a nano-material dispersion. N5. Add the first-component modified sand to the nano-material dispersion with a liquid-solid ratio of (1.5 - 2.5):1, stir at room temperature for 2 - 4 hours, filter, and dry at 60 - 80 °C for 3 - 5 hours to obtain the two-component nano-modified manufactured sand.

7. An anti-seepage repair material for building expansion joints according to claim 6, characterized in that, The manufactured sand is one or a mixture of several of river sand, limestone manufactured sand, basalt manufactured sand, or granite manufactured sand, where the fineness modulus of the sand is 2.3 - 3.5 and the stone powder content is 2 - 8%.

8. The anti-seepage repair material for building expansion joints according to claim 1, characterized in that, The organosilicon-modified polyether capping agent is prepared by reacting polydimethylsiloxane and polyether at a weight ratio of 1:(2 - 4) at 110 - 130 °C for 3 - 5 hours under the action of a catalyst.

9. An anti-seepage repair material for building expansion joints according to claim 1, characterized in that, The multifunctional composite catalyst system includes the following components: organic amine catalysts, organic peroxides, and metal chelates, with a weight ratio of (0.2 - 0.4):(0.1 - 0.3):(0.2 - 0.5).

10. A preparation method of an anti-seepage repair material for building expansion joints, which is used to prepare an anti-seepage repair material for building expansion joints as described in any one of claims 1-9, characterized in that, It includes the following steps: B1. Under nitrogen protection, mix nano-modified polyurethane acrylate, bio-based modified acrylate, and modified lignin, heat up to 60 - 70 °C, and stir for 20 - 30 minutes. B2. Heat up to 130 - 150 °C, add environmentally friendly asphalt, and stir for 15 - 25 minutes. B3. Cool down to 50 - 60 °C, add the organosilicon-modified polyether capping agent, stir for 10 - 20 minutes, and cool to room temperature to obtain the matrix material. B4. Thoroughly mix high-performance portland cement, expansive inorganic mineral combination, and two-component nano-modified manufactured sand for 2 - 4 minutes to obtain the solid component. B5. Mix the solid component with the matrix material, add the microcapsule self-healing component, stir at low speed at 35 - 45 °C for 2 - 3 minutes, then add the functionalized fiber reinforcement material and the multifunctional composite catalyst system, stir for 3 - 5 minutes, and finally perform ultrasonic treatment for 1 - 2 minutes to promote the uniform dispersion of the components to obtain the anti-seepage repair material.