A kind of impermeable repair material for building expansion joint and preparation method

Abstract

The application discloses a kind of impermeable repair materials for building expansion joint and preparation method, belong to building engineering material technical field.According to weight fraction, the impermeable repair material includes the following components: nano modified polyurethane acrylate 8-12 parts;Bio-based modified acrylate 5-8 parts;Modified lignin 3-6 parts;Environment-friendly asphalt 4-7 parts;High-performance Portland cement 4-7 parts;Expanding inorganic mineral combination 8-12 parts;Microcapsule self-repairing component 1-2 parts;Functionalized fiber reinforced material 1-3 parts;Two-component nano modified machine-made sand 55-65 parts;Organic silicon modified polyether end-capping agent 0.8-1.2 parts;Multifunctional composite catalyst system 0.5-1.5 parts.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of building engineering materials, and more particularly to a seepage-proof repairing material for a building expansion joint and a preparation method. BACKGROUND

[0002] During long-term service, buildings are inevitably affected by temperature changes, foundation settlement, structural loads and other factors, and a certain degree of displacement or deformation will occur between the components. In order to avoid cracks or other damage to the structure due to limited deformation, expansion joints are usually provided at key positions such as beams, slabs, pavements, tunnels and bridge decks to buffer deformation and release stress. However, although the expansion joint structure has functionality, it is also a weak link for rainwater seepage, chloride salt erosion and pollutant intrusion, especially under heavy traffic or complex climate conditions, and its sealing performance and durability are often severely tested.

[0003] In order to improve the seepage-proof and durability performance of the building expansion joint, sealant, modified asphalt, epoxy resin and other materials are currently used to seal or repair the expansion joint. However, these traditional materials generally have poor adhesion, insufficient durability, easy aging and cracking, and other problems, and are difficult to meet the long-term service and frequent deformation use scenarios. In addition, some materials rely on solvents or high-temperature treatment during construction, which has environmental hazards or high operation difficulty, and also limits their popularization and application in complex working conditions.

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

[0005] In summary, how to develop a new type of composite material and its preparation method which is stable in performance, environmentally friendly, has good adhesion and self-repairing ability, and is suitable for seepage-proof repairing of building expansion joints, has become a technical problem to be solved. SUMMARY

[0006] In order to overcome a series of defects existing in the prior art, the purpose of the present application is to provide a kind of anti-infiltration repair material for building expansion joint, by weight fraction, the anti-infiltration repair material includes the following components: nano modified polyurethane acrylate 8-12 parts;Bio-based modified acrylate 5-8 parts;Modified lignin 3-6 parts;Environment-friendly asphalt 4-7 parts;High-performance Portland cement 4-7 parts;Expanding inorganic mineral combination 8-12 parts;Microcapsule self-repairing component 1-2 parts;Functionalized fiber reinforced material 1-3 parts;Two-component nano modified machine-made sand 55-65 parts;Silicone modified polyether end-capping agent 0.8-1.2 parts;Multifunctional composite catalyst system 0.5-1.5 parts.

[0007] Preferably, the nano modified polyurethane acrylate is prepared by heating polyurethane acrylate to 60-70℃, adding 1-3% of amino modified nano silicon dioxide particles by weight under stirring, continuing to heat to 80-90℃, stirring for 2-4 hours, and then cooling to room temperature.

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

[0009] Preferably, the bio-based modified acrylate is prepared by adding 15-25% of soybean oil fatty acid derivatives and 5-10% of sesame oil fatty acid esters by weight in polyacrylate, stirring under nitrogen protection at 70-80℃ for 3-5 hours.

[0010] Preferably, the general formula of bio-based modified acrylate is: PAA-[COOCH2(CH=CH) x R] m , wherein PAA is a polyacrylate backbone;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 with maleic anhydride at a weight ratio of 3:1-5:1, esterification reaction at 150-170℃ for 2-3 hours, and then ring-opening reaction with epoxy resin at a weight ratio of 2:1-4:1 for 1-2 hours.

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

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

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

[0015] Preferably, the microcapsule self-repairing component is an epoxy resin curing agent wrapped by polyurea microcapsules, the microcapsule diameter is 50-200μm, the wall thickness is 2-5μm, and the microcapsule releases the curing agent to react with the epoxy groups in the matrix to form a crosslinked network when it is broken by pressure or shear force.

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

[0017] Preferably, the two-component nano-modified machine-made sand is prepared by the following steps: N1, soaking the machine-made 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 machine-made sand; N2, mixing γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane at a weight ratio of 1:(1-3), diluting with methanol 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 machine-made sand to the silane coupling agent solution, stirring at room temperature for 4-6 hours, filtering, and drying at 60-80℃ for 3-5 hours to obtain a first-component modified sand; N4, dispersing amino-modified nano-silicon dioxide and amino-modified graphene in ethanol at a weight ratio of (8-12):(0.5-1.5), and ultrasonic treating for 1-2 hours to obtain a nanomaterial dispersion liquid; N5, adding the first-component modified sand to the nanomaterial dispersion liquid, stirring at room temperature for 2-4 hours, filtering, and drying at 60-80℃ for 3-5 hours to obtain a two-component nano-modified machine-made sand.

[0018] Preferably, the machine-made sand is one or a mixture of several of river sand, limestone machine-made sand, basalt machine-made sand or granite machine-made sand, wherein the sand has a fineness modulus of 2.3-3.5 and a stone powder content of 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) under the action of a catalyst at 110-130 DEG C for 3-5 hours.

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

[0021] In addition, the application also provides a preparation method of the above-mentioned anti-seepage repair material, comprising the following steps: B1, under the protection of nitrogen, mixing nano-modified polyurethane acrylate, bio-based modified acrylate and modified lignin, heating to 60-70 DEG C and stirring for 20-30 minutes; B2, heating to 130-150 DEG C, adding environmentally friendly asphalt and stirring for 15-25 minutes; B3, cooling to 50-60 DEG C, adding silicone-modified polyether end-capping agent and stirring for 10-20 minutes, cooling to room temperature to obtain a base material; B4, fully mixing high-performance Portland cement, expansion-type inorganic mineral combination and two-component nano-modified machine-made sand for 2-4 minutes to obtain a solid component; B5, mixing the solid component with the base material, adding microcapsule self-repairing component, stirring at a low speed for 2-3 minutes at 35-45 DEG C, then adding functionalized fiber reinforcing material and multifunctional composite catalyst system, stirring for 3-5 minutes, and finally performing ultrasonic treatment for 1-2 minutes to promote uniform dispersion of the components, thereby obtaining the anti-seepage repair material.

[0022] Compared with the prior art, the application has the beneficial effects that: by introducing nano-modification, bio-based modification, self-repairing microcapsules and two-component modified machine-made sand, the application realizes the organic unity of high strength, environmental protection, self-repairing and excellent anti-seepage performance of the material. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the application.

[0024] In one broad embodiment of the present application, an anti-permeation repair material for building expansion joints, the anti-permeation repair material comprises the following components by weight fraction: nano-modified polyurethane acrylate 8-12 parts; bio-based modified acrylate 5-8 parts; modified lignin 3-6 parts; environmentally friendly asphalt 4-7 parts; high-performance Portland cement 4-7 parts; expanded inorganic mineral combination 8-12 parts; microcapsule self-repairing component 1-2 parts; functionalized fiber reinforced material 1-3 parts; two-component nano-modified machine-made sand 55-65 parts; silicone-modified polyether end-capping agent 0.8-1.2 parts; multifunctional composite catalyst system 0.5-1.5 parts.

[0025] Preferably, the nano-modified polyurethane acrylate is prepared by heating the polyurethane acrylate to 60-70℃, adding 1-3% of amino-modified nano-silica particles by weight under stirring, continuing to heat to 80-90℃, stirring for 2-4 hours, and then cooling to room temperature.

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

[0027] Preferably, the bio-based modified acrylate is prepared by adding 15-25% of soybean oil fatty acid derivatives and 5-10% of sesame oil fatty acid esters by weight in the polyacrylate, stirring under nitrogen protection at 70-80℃ for 3-5 hours.

[0028] Preferably, the general formula of the bio-based modified acrylate is: PAA-[COOCH2(CH=CH) x R] m , wherein PAA is a polyacrylate backbone; 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 with maleic anhydride at a weight ratio of 3:1-5:1, esterification reaction at 150-170℃ for 2-3 hours, and then ring-opening reaction with epoxy resin at a weight ratio of 2:1-4:1 for 1-2 hours.

[0030] Preferably, the general 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 group segment, p = 1-4.

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

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

[0033] Preferably, the microcapsule self-repairing component is an epoxy resin curing agent wrapped by polyurea microcapsules, the microcapsule diameter is 50-200μm, the wall thickness is 2-5μm, and the microcapsule releases the curing agent when it is broken by pressure or shear force, and the curing agent reacts with the epoxy groups in the matrix to form a crosslinked network.

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

[0035] Preferably, the two-component nano-modified machine-made sand is prepared by the following steps: N1, soaking the machine-made 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 machine-made sand; N2, mixing γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane at a weight ratio of 1:(1-3), diluting with methanol 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 machine-made sand to the silane coupling agent solution, stirring at room temperature for 4-6 hours, filtering, and drying at 60-80℃ for 3-5 hours to obtain a first component modified sand; N4, dispersing amino-modified nano-silicon dioxide and amino-modified graphene in ethanol at a weight ratio of (8-12):(0.5-1.5), and ultrasonic treating for 1-2 hours to obtain a nano-material dispersion liquid; N5, adding the first component modified sand to the nano-material dispersion liquid, stirring at room temperature for 2-4 hours, filtering, and drying at 60-80℃ for 3-5 hours to obtain a two-component nano-modified machine-made sand.

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

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

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

[0039] In addition, the application also provides a preparation method of the above-mentioned anti-seepage repair material, comprising the following steps: B1, under the protection of nitrogen, nano-modified polyurethane acrylate, bio-based modified acrylate and modified lignin are mixed, and the temperature is raised to 60-70 DEG C, and stirring treatment is carried out for 20-30 minutes; B2, the temperature is raised to 130-150 DEG C, and the environmentally friendly asphalt is added, and stirring treatment is carried out for 15-25 minutes; B3, the temperature is lowered to 50-60 DEG C, and the silicone-modified polyether end-capping agent is added, and stirring treatment is carried out for 10-20 minutes, and then cooled to room temperature to obtain the base material; B4, the high-performance silicate cement, the expanded inorganic mineral combination and the two-component nano-modified machine-made sand are fully mixed for 2-4 minutes to obtain the solid component; B5, the solid component is mixed with the base material, the microcapsule self-repairing component is added, low-speed stirring is carried out at 35-45 DEG C for 2-3 minutes, then the functionalized fiber reinforcing material and the multifunctional composite catalyst system are added, stirring treatment is carried out for 3-5 minutes, and finally ultrasonic treatment is carried out for 1-2 minutes to promote uniform dispersion of the components, and the anti-seepage repair material is obtained.

[0040] The following examples 1-3 of the application are listed to further illustrate the application.

[0041] Example 1.

[0042] In this embodiment, the anti-seepage repair material comprises the following components by weight: 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 silicate cement; 10 parts of expanded inorganic mineral combination; 1.5 parts of microcapsule self-repairing component; 2 parts of functionalized fiber reinforcing material; 60 parts of two-component nano-modified machine-made sand; 1 part of silicone-modified polyether end-capping agent; and 1 part of multifunctional composite catalyst system.

[0043] In this embodiment, the nano-modified polyurethane acrylate is prepared by the following method: polyurethane acrylate is heated to 65 DEG C, 2% of amino-modified nano-silicon dioxide particles by weight are added under stirring, the temperature is continuously raised to 85 DEG C, stirring reaction is carried out for 3 hours, and then cooled to room temperature.

[0044] In this embodiment, the bio-based modified acrylate is prepared by the following method: 20% of soybean oil fatty acid derivatives and 7% of rapeseed oil fatty acid ester by weight are added to polyacrylate, stirring reaction is carried out at 75 DEG C for 4 hours under the protection of nitrogen to obtain the bio-based modified acrylate.

[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, esterification is carried out at 160°C for 2.5 hours, and then ring-opening reaction is carried out with epoxy resin at a weight ratio of 3:1 for 1.5 hours to obtain.

[0046] In this embodiment, the environmentally 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% SBS modifier is added and stirred and mixed at 170°C for 1 hour to obtain.

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

[0048] In this embodiment, the microcapsule self-repairing component is an epoxy resin curing agent wrapped by polyurea microcapsules, the microcapsule diameter is 100μm, the wall thickness is 3μm, and the microcapsule releases the curing agent when it is broken by pressure or shear force, and the curing agent reacts with the epoxy groups in the matrix to form a crosslinked network. The microcapsule is prepared by interfacial polymerization, and the specific method is as follows: 4 parts of epoxy resin curing agent (polyether amine) is dissolved in 6 parts of cyclohexane to form an organic phase; 2 parts of polyisocyanate prepolymer is 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 under stirring at 30°C, and the reaction is carried out for 3 hours to form a polyurea wall layer; filtration, water washing and vacuum drying are carried out to obtain the microcapsule self-repairing component.

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

[0050] In this embodiment, the two-component nano-modified machine-made sand is prepared by the following steps: (1) river sand (fineness modulus of 2.8, stone powder content of 5%) is soaked in a sodium hydroxide solution with a mass concentration of 8% for 3 hours, filtered, washed with water until neutral, and dried at 70°C to obtain alkali-treated machine-made sand; (2) γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane are mixed at a weight ratio of 1:2, diluted with methanol to a total solid content of 4%, and the pH is adjusted to 4.5, and hydrolyzed for 3 hours to obtain a silane coupling agent solution; (3) the alkali-treated machine-made sand is added to the silane coupling agent solution, the liquid-solid ratio is 2.5:1, and stirring treatment is carried out at room temperature for 5 hours, filtered, and dried at 70°C for 4 hours to obtain the first component modified sand; (4) the amino-modified nanosilica and the amino-modified graphene are dispersed in ethanol at a weight ratio of 10:1, and ultrasonic treatment is carried out for 1.5 hours to obtain a nanomaterial dispersion liquid; (5) the first component modified sand is added to the nanomaterial dispersion liquid, the liquid-solid ratio is 2:1, and stirring treatment is carried out at room temperature for 3 hours, filtered, and dried at 70°C for 4 hours to obtain the two-component nano-modified machine-made sand.

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

[0052] In this embodiment, the multifunctional composite catalyst system includes the following components: dimethylbenzylamine (organic amine catalyst), benzoyl peroxide (organic peroxide), and zinc acetylacetone (metal chelate), and the weight ratio 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 the protection of nitrogen, nano-modified polyurethane acrylate, bio-based modified acrylate, and modified lignin are mixed, and the temperature is raised to 65°C for stirring treatment for 25 minutes; (2) the temperature is raised to 140°C, and environmentally friendly asphalt is added for stirring treatment for 20 minutes; (3) the temperature is lowered to 55°C, and organosilicon-modified polyether capping agent is added for stirring treatment for 15 minutes, and then cooled to room temperature to obtain a base material; (4) high-performance Portland cement, expansion-type 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 base material, microcapsule self-repairing component is added, and low-speed stirring is carried out at 40°C for 2.5 minutes, then functionalized fiber reinforcing material and multifunctional composite catalyst system are added, stirring treatment is carried out for 4 minutes, and finally ultrasonic treatment is carried out for 1.5 minutes to promote uniform dispersion of the components, and the anti-seepage repair material is obtained.

[0054] Example 2.

[0055] In this embodiment, the anti-permeation repair material includes the following components by weight: 12 parts of nano-modified polyurethane acrylate; 8 parts of bio-based modified acrylate; 6 parts of modified lignin; 7 parts of environmentally friendly asphalt; 7 parts of high-performance Portland cement; 12 parts of expanded inorganic mineral combination; 2 parts of microcapsule self-repairing component; 3 parts of functionalized fiber reinforcing material; 65 parts of two-component nano-modified machine-made sand; 1.2 parts of silicone-modified polyether blocking agent; and 1.5 parts of multifunctional composite catalyst system.

[0056] In this embodiment, the nano-modified polyurethane acrylate is prepared by heating the polyurethane acrylate to 70°C, adding 3% of amino-modified nano-silicon dioxide particles by weight under stirring, continuing to heat to 90°C, stirring for 4 hours, and then cooling to room temperature.

[0057] In this embodiment, the bio-based modified acrylate is prepared by adding 25% of soybean oil fatty acid derivatives and 10% of sesame oil fatty acid esters by weight in the polyacrylate, stirring under nitrogen protection at 80°C for 5 hours, and then obtaining the product.

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

[0059] In this embodiment, the environmentally friendly asphalt is prepared by mixing biomass pyrolysis oil and petroleum asphalt at a weight ratio of 5:5, adding 3% of SBS modifier, and stirring and mixing at 180°C for 1.5 hours.

[0060] In this embodiment, the expanded inorganic mineral combination includes the following components: expanded perlite powder, bentonite, silica fume, and magnesium oxide, with a weight ratio of 5:4:3:2.

[0061] In this embodiment, the microcapsule self-repairing component is an epoxy resin curing agent wrapped by polyurea microcapsules, with a microcapsule diameter of 150μm and a wall thickness of 4μm. When the microcapsule is broken 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 microcapsule is prepared by interfacial polymerization, and the specific method is as follows: 5 parts of epoxy resin curing agent (aromatic amine) are dissolved in 7 parts of cyclohexane to form an organic phase; 3 parts of polyisocyanate prepolymer are dissolved in 12 parts of ethyl acetate; the organic phase is dispersed in an aqueous solution containing 1.5% of polyvinyl alcohol to form an O / W emulsion; the polyisocyanate prepolymer solution is added dropwise under stirring at 35°C, and the reaction is carried out for 4 hours to form a polyurea wall layer; filtration, water washing, and vacuum drying are performed to obtain the microcapsule self-repairing component.

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

[0063] In this embodiment, the two-component nano-modified machine-made sand is prepared by the following steps: (1) basalt machine-made sand (fineness modulus of 3.0, stone powder content of 6%) is soaked in a sodium hydroxide solution with a mass concentration of 10% for 4 hours, filtered, washed with water to neutral, and dried at 80℃ to obtain alkali-treated machine-made sand; (2) γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane are mixed in a weight ratio of 1:3, diluted with methanol to a total solid content of 5%, the pH is adjusted to 4, and hydrolyzed for 4 hours to obtain a silane coupling agent solution; (3) the alkali-treated machine-made sand is added to the silane coupling agent solution, the liquid-solid ratio is 3:1, stirred at room temperature for 6 hours, filtered, and dried at 80℃ for 5 hours to obtain a first-component modified sand; (4) amino-modified nanosilica and amino-modified graphene are dispersed in ethanol in a weight ratio of 12:1.5, and ultrasonic treatment is performed for 2 hours to obtain a nanomaterial dispersion liquid; (5) the first-component modified sand is added to the nanomaterial dispersion liquid, the liquid-solid ratio is 2.5:1, stirred at room temperature for 4 hours, filtered, and dried at 80℃ for 5 hours to obtain a two-component nano-modified machine-made sand.

[0064] In this embodiment, the silicone-modified polyether capping agent is prepared by the following method: polydimethylsiloxane and polyether are reacted at a weight ratio of 1:4 under the action of dibutyltin dilaurate catalyst (0.8% of the total weight) at 130℃ for 5 hours.

[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), the weight ratio is 0.4:0.3:0.8.

[0066] In this embodiment, the preparation method of the anti-seepage repair material includes the following steps: (1) under the protection of nitrogen, mix nano-modified polyurethane acrylate, bio-based modified acrylate and modified lignin, heat to 70℃ and stir for 30 minutes; (2) heat to 150℃, add environmentally friendly asphalt and stir for 25 minutes; (3) cool to 60℃, add silicone-modified polyether capping agent and stir for 20 minutes, cool to room temperature to obtain the base material; (4) mix high-performance Portland cement, expansion-type inorganic mineral combination and two-component nano-modified machine-made sand for 4 minutes to obtain the solid component; (5) mix the solid component with the base material, add microcapsule self-repairing component, stir at low speed at 45℃ for 3 minutes, then add functionalized fiber reinforcing material and multifunctional composite catalyst system, stir for 5 minutes, and finally perform ultrasonic treatment for 2 minutes to promote uniform dispersion of the components, thereby obtaining the anti-seepage repair material.

[0067] Example 3.

[0068] In this embodiment, the anti-seepage repair material includes the following components by weight: nano-modified polyurethane acrylate 8 parts; bio-based modified acrylate 5 parts; modified lignin 3 parts; environmentally friendly asphalt 4 parts; high-performance Portland cement 4 parts; expansion-type inorganic mineral combination 8 parts; microcapsule self-repairing component 1 part; functionalized fiber reinforcing material 1 part; two-component nano-modified machine-made sand 55 parts; silicone-modified polyether capping agent 0.8 parts; and multifunctional composite catalyst system 0.5 parts.

[0069] In this embodiment, the nano-modified polyurethane acrylate is prepared by heating polyurethane acrylate to 60℃, adding 1% of amino-modified nano-silicon dioxide particles by weight under stirring, continuing to heat to 80℃, stirring for 2 hours, and then cooling to room temperature.

[0070] In this embodiment, the bio-based modified acrylate is prepared by adding 15% of soybean oil fatty acid derivatives and 5% of sesame oil fatty acid esters by weight in polyacrylate, stirring at 70℃ for 3 hours under nitrogen protection, and then cooling to room temperature.

[0071] In this embodiment, the modified lignin is prepared by mixing lignin and maleic anhydride at a weight ratio of 3:1, performing esterification reaction at 150℃ for 2 hours, and then performing ring-opening reaction with epoxy resin at a weight ratio of 2:1 for 1 hour.

[0072] In this embodiment, the environmentally friendly asphalt is prepared by mixing biomass pyrolysis oil and petroleum asphalt at a weight ratio of 3:7, adding 1% of SBS modifier, and stirring and mixing at 160℃ for 0.5 hours.

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

[0074] In this embodiment, the microcapsule self-repairing component is an epoxy resin curing agent wrapped by polyurea microcapsules, the diameter of the microcapsule is 50 μm, and the wall thickness is 2 μm. When the microcapsule is broken by pressure or shear force, the curing agent is released to react with the epoxy groups in the matrix to form a crosslinked network. The microcapsule is prepared by interfacial polymerization. Specifically, 3 parts of epoxy resin curing agent (fatty amine) is dissolved in 5 parts of cyclohexane to form an organic phase; 1 part of polyisocyanate prepolymer is dissolved in 8 parts of ethyl acetate; the organic phase is dispersed in an aqueous solution containing 0.8% polyvinyl alcohol to form an O / W emulsion; the polyisocyanate prepolymer solution is added dropwise under stirring at 25°C, and the reaction is carried out for 2 hours to form a polyurea wall layer; filtration, water washing and vacuum drying are carried out to obtain the microcapsule self-repairing component.

[0075] In this embodiment, the functionalized fiber reinforced material comprises the following components: polyvinyl alcohol fiber, polypropylene fiber and basalt fiber, and the 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 machine-made sand is prepared by the following steps: (1) granite machine-made sand (fineness modulus of 2.5, stone powder content of 3%) is soaked in a sodium hydroxide solution with a mass concentration of 5% for 2 hours, filtered, washed to neutral, and dried at 60°C to obtain alkali-treated machine-made sand; (2) γ-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane are mixed in a weight ratio of 1:1, diluted with methanol to a total solid content of 3%, and the pH is adjusted to 5, and hydrolyzed for 2 hours to obtain a silane coupling agent solution; (3) the alkali-treated machine-made sand is added to the silane coupling agent solution, and the liquid-solid ratio is 2:1, and stirred at room temperature for 4 hours, filtered, and dried at 60°C for 3 hours to obtain the first component modified sand; (4) amino-modified nano-silicon dioxide and amino-modified graphene are dispersed in ethanol in a weight ratio of 8:0.5, and ultrasonic treatment is carried out for 1 hour to obtain a nano-material dispersion liquid; (5) the first component modified sand is added to the nano-material dispersion liquid, and the liquid-solid ratio is 1.5:1, and stirred at room temperature for 2 hours, filtered, and dried at 60°C for 3 hours to obtain the two-component nano-modified machine-made sand.

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

[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 acetylacetone magnesium (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) mixing the nano-modified polyurethane acrylate, the bio-based modified acrylate, and the modified lignin under nitrogen protection, heating to 60°C, and stirring for 20 minutes; (2) heating to 130°C, adding the environmentally friendly asphalt, and stirring for 15 minutes; (3) cooling to 50°C, adding the silicone-modified polyether end-capping agent, stirring for 10 minutes, cooling to room temperature, and obtaining the base material; (4) fully mixing the high-performance Portland cement, the expanded inorganic mineral combination, and the two-component nano-modified machine-made sand for 2 minutes to obtain the solid component; (5) mixing the solid component with the base material, adding the microcapsule self-repairing component, stirring at a low speed for 2 minutes at 35°C, then adding the functionalized fiber reinforcing material and the multifunctional composite catalyst system, stirring for 3 minutes, and finally performing ultrasonic treatment for 1 minute to promote uniform dispersion of the components, thereby obtaining the anti-seepage repair material.

[0080] The anti-seepage repair materials prepared in Examples 1-3 were subjected to performance testing, and 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 impermeability was greater than 72 hours, the elongation rate was 135%, the weather resistance was 300 cycles, the freeze-thaw resistance was 150 cycles, and the self-repairing 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 impermeability was greater than 96 hours, the elongation rate was 150%, the weather resistance was 350 cycles, the freeze-thaw resistance was 180 cycles, and the self-repairing 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 impermeability was greater than 48 hours, the elongation rate was 120%, the weather resistance was 250 cycles, the freeze-thaw resistance was 120 cycles, and the self-repairing efficiency was 68%.

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

[0082] Self-repairing efficiency test method: the sample was stretched to appear micro-cracks (width of about 100 μm), then placed in standard environment (temperature 23±2℃, relative humidity 50±5%) for 7 days, and then the tensile strength test was carried out again, and the self-repairing efficiency was expressed as the percentage of the strength after repair to the original strength.

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

[0084] The anti-seepage repair material prepared in Example 1 was applied to the anti-seepage repair project of the expansion joint of the underground garage of a large commercial complex. The total length of the expansion joint of the project is about 120 meters, the width is 40-60 mm, the maximum displacement is ±20 mm, and there is a significant seepage phenomenon. 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 debris 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 the application into the expansion joint and compact it with a special tool; (5) surface treatment: use a spatula to smooth 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), there was no seepage phenomenon at the repaired part. In the artificial loading test, the expansion joint can normally expand and contract, and the anti-seepage repair material does not appear to be broken or detached. After 9 months of use, the repaired part still maintains good anti-seepage effect and mechanical properties.

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

[0087] In the above examples 1-3, the polyurethane acrylate used was purchased from Guangdong Boxin New Material Technology Co., Ltd. (model B-369), the amino-modified nano-silicon dioxide particles were selected from amino-silicon dioxide microspheres produced by Nanjing Gike Biological Technology Co., Ltd., the polyacrylate was selected from polyacrylate emulsion produced by Beijing Dechangweiye Building Engineering Technology Co., Ltd., the soybean oil fatty acid derivative was selected from soybean oil fatty acid produced by Shandong Xinxian Lishengyuan New Energy Co., Ltd., the rapeseed oil fatty acid ester was produced by Hebei Xinqidian Biological Technology Co., Ltd. Lignin was produced by Tianjin Deqian Lignin Technology Co., Ltd., maleic anhydride was from Zibo Lishuo Chemical Co., Ltd., epoxy resin used NPES-901 resin produced by Nan Ya (Kunshan) Co., Ltd., biomass pyrolysis oil was purchased from Zhengzhou Hui Lv Technology Co., Ltd. Petroleum asphalt used "Beilie" petroleum asphalt (model AH-90) produced by Panjin Beifang Asphalt Fuel Co., Ltd., SBS modifier was provided by Huizhou Li Changrong Chemical (model 3501F), expanded perlite powder was produced by Zibo Zhangdian Pengyue Insulation Material Factory, bentonite was selected from JF-27 type bentonite produced by Zhejiang Fenghong New Material Co., Ltd., silica fume was selected from concrete silica fume produced by Shijiazhuang Tomarin Mineral Products Co., Ltd., magnesium oxide used 8161 type high-purity magnesium oxide produced by Weifang Wanfeng New Material Technology Co., Ltd. Epoxy resin curing agent was produced by Changzhou Shanfeng Chemical Co., Ltd., cyclohexane was produced by Shandong Yuhuang Chemical Group Co., Ltd., ethyl acetate was selected from industrial ethyl acetate produced by Shandong Jin Yimeng Group Co., Ltd., polyisocyanate prepolymer was produced by Zibo Yahua Xin Rubber and Plastic Co., Ltd. Polyvinyl alcohol was produced by Anhui Wanwei New Material Co., Ltd., polyvinyl alcohol fiber was produced by Jiangxi Xianmai New Material Technology Co., Ltd., polypropylene fiber was produced by Jiangsu Bote New Material Co., Ltd., basalt fiber was produced by Sichuan Hangtai Taoxi Basalt Industry Co., Ltd. River sand was building grade river sand provided by local building material suppliers, sodium hydroxide was produced by China Haohua Chemical Group Co., Ltd., gamma-glycidoxypropyltrimethoxysilane was produced by Nanjing Daoning Chemical Co., Ltd., 3-aminopropyltrimethoxysilane was produced by Hangzhou Silibao 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 Material Technology Co., Ltd., polydimethylsiloxane was produced by Xin'an Chemical Group Co., Ltd., polyurea microcapsules were produced by Shandong Lianxin New Material Industry Co., Ltd., polyether was produced by Shanghai Gaoqiao Petrochemical Co., Ltd. Dibutyltin dilaurate catalyst was produced by Jinan Jinhuo 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 Additives Co., Ltd., high-performance Portland cement used p.o42.5 cement produced by Anhui Conch Cement Co., Ltd.

[0088] Finally, it should be pointed out that: the above examples are only to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part 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. A waterproofing and repair material for building expansion joints, characterized in that, By weight, the seepage prevention and 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 environmentally friendly asphalt; 4-7 parts high-performance silicate cement; 8-12 parts expansive inorganic mineral blend; 1-2 parts of microcapsule self-repairing component; Functionalized fiber-reinforced material 1-3 parts; two-component nano-modified manufactured sand 55-65 parts; 0.8-1.2 parts of organosilicon-modified polyether end-capping agent; 0.5-1.5 parts of a multifunctional composite catalyst system; The nano-modified polyurethane acrylate is prepared by the following steps: heating the polyurethane acrylate to 60-70°C, adding 1-3% of its weight of amino-modified nano silica particles under stirring, continuing to heat to 80-90°C, stirring and reacting for 2-4 hours, and then cooling to room temperature to obtain the product. The bio-based modified acrylate is prepared by the following steps: adding 15-25% soybean oil fatty acid derivative and 5-10% hemp seed oil fatty acid ester by weight to polyacrylate, and stirring and reacting at 70-80°C for 3-5 hours under nitrogen protection. The modified lignin is obtained by mixing lignin with maleic anhydride at 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 at a weight ratio of 2:1-4:1 for 1-2 hours. The general formula of the nano-modified polyurethane acrylate is: PU-(CH2CHCOO). n +SiO2-NH2, where: PU is a polyester or polyether polyurethane segment; n=2-5; The general formula for bio-based modified acrylates is: PAA-[COOCH2(CH=CH)] x R] m Wherein, PAA is the polyacrylate backbone; x = 1-2; R is the natural fatty acid group; m is the degree of substitution, m = 0.15-0.35; The general formula for modified lignin is: Lignin-OCOCH=CHCOO-[CH2CH(OH)CH2] p Where: Lignin is the lignin group; p represents the length of the epoxy group segment, p = 1–4; The environmentally 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% SBS modifier. The expanded inorganic mineral assemblage comprises the following components: expanded perlite powder, bentonite, silica fume and magnesium oxide, in a weight ratio of (3-5):(2-4):(2-3):(1-2); The microcapsule self-healing component is an epoxy resin curing agent encapsulated in polyurea microcapsules. The microcapsules have a diameter of 50-200 μm and a wall thickness of 2-5 μm. When the microcapsules are subjected to pressure or shear force and rupture, they release the curing agent, which reacts with the epoxy groups in the matrix to form a cross-linked network. The two-component nano-modified manufactured sand is prepared using the following steps: N1. The manufactured sand is soaked in a 5-10% sodium hydroxide solution for 2-4 hours, filtered, washed with water, and dried to obtain alkali-treated manufactured sand; N2. γ-glycidyl etheroxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane are mixed at a weight ratio of 1:(1-3), diluted with methanol to a total solid content of 3-5%, the pH is adjusted to 4-5, and hydrolyzed for 2-4 hours to obtain a silane coupling agent solution; N3. The alkali-treated manufactured sand is added to the silane coupling agent solution, with a liquid-to-solid ratio of (2- 3):1, Stir at room temperature for 4-6 hours, filter, and dry at 60-80℃ 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 sonicate for 1-2 hours to obtain a nanomaterial dispersion; N5, Add the first component modified sand to the nanomaterial dispersion at a liquid-solid ratio of (1.5-2.5):1, stir at room temperature for 2-4 hours, filter, and dry at 60-80℃ for 3-5 hours to obtain a two-component nano-modified machined sand; The functionalized fiber-reinforced material comprises the following components: polyvinyl alcohol fiber, polypropylene fiber, and basalt fiber, with a weight ratio of (0.5-1):(0.3-0.7):(0.2-0.5), and a fiber length of 3-12 mm. The manufactured sand is one or a mixture of several of the following: 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%; The organosilicon-modified polyether end-capping agent is prepared by reacting polydimethylsiloxane and polyether at a weight ratio of 1:(2-4) at 110-130℃ for 3-5 hours under the action of a catalyst. The preparation method of the waterproofing and repair material for building expansion joints includes the following steps: B1. Under nitrogen protection, nano-modified polyurethane acrylate, bio-based modified acrylate, and modified lignin are mixed, heated to 60-70℃, and stirred for 20-30 minutes; B2. Heating to 130-150℃, environmentally friendly asphalt is added, and stirred for 15-25 minutes; B3. Cooling to 50-60℃, organosilicon-modified polyether end-capping agent is added, stirred for 10-20 minutes, and cooled to room temperature to obtain the matrix material; B4. High-performance silicate cement, expansive inorganic mineral combination, and two-component nano-modified manufactured sand are thoroughly mixed for 2-4 minutes to obtain the solid component; B5. The solid component is mixed with the matrix material, microcapsule self-healing component is added, and stirred at low speed at 35-45℃ for 2-3 minutes. Then, functionalized fiber reinforcement material and multifunctional composite catalyst system are added, stirred for 3-5 minutes, and finally ultrasonic treatment is performed for 1-2 minutes to promote uniform dispersion of the components, thus obtaining the waterproofing and repair material.

2. The waterproofing and repair material for building expansion joints according to claim 1, characterized in that, The multifunctional composite catalyst system comprises the following components: organic amine catalyst, organic peroxide and metal chelate, in a weight ratio of (0.2-0.4):(0.1-0.3):(0.2-0.5).