Preparation method of anti-cracking epoxy resin concrete
By using resveratrol-modified epoxy resin and polyurethane prepolymer for chemical crosslinking, as well as sodium oleate-modified basalt fiber, the problem of easy cracking of concrete structures under load, temperature difference and environmental erosion was solved, and the mechanical properties and durability of concrete were improved.
Patent Information
- Application Number
- CN202511116577.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-11
- Publication Date
- 2025-12-26
AI Technical Summary
Existing concrete structures are prone to cracking under load, shrinkage, temperature difference and environmental erosion. In particular, cracks expand in cold or saline-alkali corrosive environments, affecting structural durability. Ordinary epoxy resin concrete has poor impact resistance and is prone to secondary cracking.
By using resveratrol-modified epoxy resin and polyurethane prepolymer for chemical crosslinking, combined with sodium oleate-modified basalt fiber, the dispersibility and corrosion resistance of the fiber in the concrete matrix are improved, thus preparing crack-resistant epoxy resin concrete.
It improves the mechanical properties and crack resistance of concrete, enhances the corrosion resistance of fibers, extends the service life of reinforced concrete, and reduces the occurrence of cracks.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of concrete, and particularly relates to a preparation method of anti-cracking epoxy resin concrete. BACKGROUND
[0002] Cracks are generated in concrete structures in the process of use due to load, shrinkage, temperature difference and environmental erosion, which significantly reduces the structural durability. Especially in the environment of high cold, large temperature difference or salt and alkali corrosion, the crack expansion caused by freeze-thaw cycle can cause large-area spalling of concrete, threatening the safety of engineering. The ordinary cement-based filler is difficult to adapt to repeated frost heaving stress, and the repair effect is short-lived. The conventional epoxy resin concrete has the problems of low impact resistance and high brittleness, and is easy to cause secondary cracking under external force. Therefore, it is urgent to develop a simple process and excellent performance modification method of epoxy resin concrete to improve the anti-cracking performance and durability of the concrete.
[0003] In order to solve the above problems and improve the mechanical properties of the epoxy resin concrete, the present application provides a preparation method of anti-cracking epoxy resin concrete. SUMMARY
[0004] The present application aims to provide a preparation method of anti-cracking epoxy resin concrete to solve the problems in the prior art.
[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: A preparation method of anti-cracking epoxy resin concrete comprises the following steps: Step one: take epoxy chloropropane and white hulless bran, heat to 108-110 DEG C, stir for 2-3h, drop sodium hydroxide aqueous solution, stir for 5-6h, add ferric chloride, stir until the color of the system is unchanged, cool to 25-30 DEG C, extract, wash, dry, rotary evaporation, and obtain epoxy resin; Step two: take polyurethane prepolymer and epoxy resin, stir for 1-2h, and obtain modified epoxy resin; Step three: take cement, fine aggregate, coarse aggregate, fly ash, silica fume, modified epoxy resin, epoxy modified basalt fiber, water reducing agent, curing agent, diluent, deionized water, mix uniformly, and obtain concrete slurry; Step four: take the concrete slurry, pour, vibration and pressure molding, store for 22-26h, demold, and maintain for 28 days, and obtain anti-cracking epoxy resin concrete.
[0006] More preferably, the concrete slurry comprises the following ingredients by weight fraction: 100-110 parts of cement, 120-125 parts of fine aggregate, 150-165 parts of coarse aggregate, 30-35 parts of fly ash, 20-22 parts of silica fume, 9-12 parts of modified epoxy resin, 6-8 parts of epoxy modified basalt fiber, 5-6 parts of water reducing agent, 3-4 parts of curing agent, 2-2.5 parts of diluent, and 22-24 parts of deionized water.
[0007] More preferably, the preparation method of the polyurethane prepolymer comprises the following steps: taking hydrogen-containing fluorosilicone oil and platinum vinylsiloxane catalyst, purging with helium, stirring, heating to 90-95℃, adding epoxy resin, stirring for 3-4h, heating to 150-152℃, adding lithium n-butoxide and diphenylmethane diisocyanate, stirring for 3-4h, adding 1,2,7,8-diepoxyoctane, and stirring for 2-3h to obtain the polyurethane prepolymer.
[0008] More preferably, the preparation method of the epoxy resin comprises the following steps: taking epoxy chloropropane and white wine, heating to 108-110℃, stirring for 2-3h, adding sodium hydroxide aqueous solution dropwise, stirring for 5-6h, adding ferric chloride, stirring until the color of the system does not change, cooling to 25-30℃, and extracting, washing, drying, and rotary evaporation to obtain the epoxy resin.
[0009] More preferably, the preparation method of the epoxy modified basalt fiber comprises the following steps: taking sodium oleate modified fiber and ethanol, ultrasonic dispersion to obtain a sodium oleate modified fiber solution; taking γ-glycidyl ether oxypropyltrimethoxysilane, ethanol, and deionized water, stirring uniformly, adding the sodium oleate modified fiber solution, heating to 60-65℃, stirring for 1-2h, filtering, washing, and drying to obtain the epoxy modified basalt fiber.
[0010] More preferably, the preparation method of the sodium oleate modified fiber comprises the following steps: taking sodium oleate and deionized water, stirring uniformly, heating to 50-55℃, adding basalt fiber, stirring for 1-2h, filtering, washing, and drying to obtain the sodium oleate modified fiber.
[0011] More preferably, the basalt fiber has a length of 1-3mm and a diameter of 5-10µm.
[0012] More preferably, in step two, the mass ratio of the polyurethane prepolymer to the epoxy resin is (20-25):(80-100).
[0013] Compared with the prior art, the present application has the following advantages: 1. The present application uses resveratrol to prepare epoxy resin, resveratrol molecules contain rigid stilbene structure and three phenolic hydroxyl groups, which can improve the heat resistance and mechanical properties of epoxy resin. The present application uses resveratrol to prepare polyurethane prepolymer, then mixes the polyurethane prepolymer and epoxy resin to prepare modified epoxy resin, which reinforces the short board of poor toughness of epoxy resin, chemical crosslinking occurs between polyurethane prepolymer and epoxy resin, which improves the crosslinking density of epoxy resin, improves the compatibility of the two, and improves the mechanical properties of concrete.
[0014] 2. The present application uses sodium oleate to modify basalt fiber, improve the corrosion resistance of basalt fiber, block the invasion of chloride ions, reduce the corrosion of steel bars, and improve the service life of reinforced concrete; however, the modification of sodium oleate can improve the hydrophobicity of basalt fiber, which can easily lead to the problem that basalt fiber is not easy to disperse in the concrete matrix and the anti-cracking performance is poor. The present application further modifies the epoxy resin to improve the dispersibility of basalt fiber in the concrete matrix, thereby improving the anti-cracking property of concrete. DETAILED DESCRIPTION
[0015] The technical solutions in the embodiments of the present application will be described below clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0016] The source and model involved in the present application are not specially limited, and exemplary include: hydrogen-containing fluorosilicone oil: model: KX-203, available from Guangzhou Kanglunxi Chemical Technology Co., Ltd.; platinum vinylsiloxane catalyst: model: 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum(0), available from Aldrich; basalt fiber: length: 1-3mm, diameter: 5-10µm; available from Shijiazhuang Mayue Building Material Co., Ltd.; cement: ordinary portland cement, P.O52.5, available from Jinan Mingzhou Chemical Co., Ltd.; silica fume from Sichuan Evin New Material Co., Ltd., model: 960U; fine aggregate: machine-made sand, silica content >98.5%, particle size 1-3mm, available from Shijiazhuang Xubang Mineral Product Processing Co., Ltd.; coarse aggregate: crushed stone, particle size 15-20mm, crushing value 10.5%, apparent density 2715 parts / m 3Water reducing agent: polycarboxylic acid water reducing agent, available from Nanjing Hongqian Environmental Protection Engineering Co., Ltd., water reducing rate of 25%, fineness of 3%; fly ash: available from Hebei Kexu Building Material Co., Ltd.; curing agent: available from Changzhou Youxi High Polymer Material Co., Ltd., model: UR-6290; diluent: available from Anhui Xinyuan Science and Technology Co., Ltd., model: XY686; epoxy resin: E44, available from Balin Petrochemical; butyl glycidyl ether: model: 501, available from Jinan Quanli New Material Co., Ltd.
[0017] Example 1: A preparation method of anti-cracking epoxy resin concrete, comprising the following steps: Step one: Preparation of epoxy resin by using white resveratrol: Take 110g of epoxy chloropropane, 45g of white resveratrol, heat to 109℃, stir for 2.5h, add 100mL of 20% sodium hydroxide aqueous solution dropwise, stir for 5.5h, add 2g of ferric trichloride, stir until the color of the system does not change, cool to 28℃, extract with 100mL of dichloromethane, wash the organic phase, dry, rotary evaporation to obtain epoxy resin; Step two: Preparation of polyurethane prepolymer by using white resveratrol: Take 220g of hydrogen-containing fluorosilicone oil, 0.012g of platinum vinyl siloxane catalyst, pass helium gas, stir, heat to 92℃, add 24g of epoxy resin prepared in step one, stir for 3.5h, heat to 151℃, add 0.2g of n-butyllithium, 50g of diphenylmethane diisocyanate, stir for 3.5h, add 12g of 1,2,7,8-epoxyoctane, stir for 2.5h, to obtain polyurethane prepolymer; Step three: Preparation of epoxy modified basalt fiber: S1: Sodium oleate modified fiber: Take 0.2g of sodium oleate, 300mL of deionized water, stir uniformly, heat to 52℃, add 12g of basalt fiber, stir for 1.5h, filter, wash, dry to obtain sodium oleate modified fiber; S2: Take 3g of sodium oleate modified fiber, 10mL of ethanol, ultrasonic dispersion to obtain sodium oleate modified fiber solution; take 6g of γ-glycidyl ether propyltrimethoxysilane, 120mL of ethanol, 5mL of deionized water, stir uniformly, add sodium oleate modified fiber solution, heat to 62℃, stir for 1.5h, filter, wash, dry to obtain epoxy modified basalt fiber; Step four: Preparation of anti-cracking epoxy resin concrete: S1: Take 20g of polyurethane prepolymer, 80g of epoxy resin, stir for 1.5h to obtain modified epoxy resin; S2: Take cement, fine aggregate, coarse aggregate, fly ash, silica fume, modified epoxy resin, epoxy modified basalt fiber, water reducing agent, curing agent, diluent, deionized water, mix evenly, get concrete slurry; The concrete slurry comprises the following ingredients, in terms of weight fraction: 105 parts of cement, 122 parts of fine aggregate, 160 parts of coarse aggregate, 32 parts of fly ash, 21 parts of silica fume, 11 parts of modified epoxy resin, 7 parts of epoxy modified basalt fiber, 5.5 parts of water reducing agent, 3.5 parts of curing agent, 2.2 parts of diluent, 23 parts of deionized water; S3: Take the concrete slurry, pour, and perform vibration and pressure forming under a vacuum degree of 0.3 MPa, with a pressure of 150 KN, a time of 90 s, and a vibration force of 120 KN; store for 24 h, demold, and maintain at 25℃ in an environment with a relative humidity greater than 95% for 28 days to obtain the anti-cracking epoxy resin concrete.
[0018] Example 2: A preparation method of an anti-cracking epoxy resin concrete, comprising the following steps: Step one: Preparation of epoxy resin by using white resveratrol: Take 110 g of epoxy chloropropane and 45 g of white resveratrol, heat to 108℃, stir for 2 h, add 100 mL of 20% sodium hydroxide aqueous solution dropwise, stir for 5 h, add 2 g of ferric trichloride, stir until the color of the system does not change, cool to 25℃, extract with 100 mL of dichloromethane, wash the organic phase, dry, and rotary evaporate to obtain the epoxy resin; Step two: Preparation of polyurethane prepolymer by using white resveratrol: Take 220 g of hydrogen-containing fluorosilicone oil and 0.012 g of platinum vinyl siloxane catalyst, pass helium gas, stir, heat to 90℃, add 24 g of the epoxy resin prepared in step one, stir for 3 h, heat to 150℃, add 0.2 g of n-butyllithium, 50 g of diphenylmethane diisocyanate, stir for 3 h, add 12 g of 1,2,7,8-diepoxyoctane, and stir for 2 h to obtain the polyurethane prepolymer; Step three: Preparation of epoxy modified basalt fiber: S1: Sodium oleate modified fiber: Take 0.2 g of sodium oleate and 300 mL of deionized water, stir evenly, heat to 50℃, add 12 g of basalt fiber, stir for 1 h, filter, wash, and dry to obtain the sodium oleate modified fiber; S2: Take 3 g of sodium oleate modified fiber and 10 mL of ethanol, ultrasonic dispersion to obtain a sodium oleate modified fiber solution; take 6 g of γ-glycidyl ether propyltrimethoxysilane, 120 mL of ethanol, and 5 mL of deionized water, stir evenly, add the sodium oleate modified fiber solution, heat to 60℃, stir for 1 h, filter, wash, and dry to obtain the epoxy modified basalt fiber; Step four: preparation of anti-cracking epoxy resin concrete: S1: take 20g polyurethane prepolymer, 80g epoxy resin, stir 1h, get modified epoxy resin; S2: take cement, fine aggregate, coarse aggregate, fly ash, silica fume, modified epoxy resin, epoxy modified basalt fiber, water reducing agent, curing agent, diluent, deionized water, mix evenly, get concrete slurry; The concrete slurry comprises the following ingredients, calculated by weight fraction: 100 parts of cement, 120 parts of fine aggregate, 150 parts of coarse aggregate, 30 parts of fly ash, 20 parts of silica fume, 9 parts of modified epoxy resin, 6 parts of epoxy modified basalt fiber, 5 parts of water reducing agent, 3 parts of curing agent, 2 parts of diluent, 22 parts of deionized water; S3: take the concrete slurry, pour, and perform vibration and pressure forming under a vacuum degree of 0.3MPa, with a pressure of 150KN, a time of 90s, and a vibration force of 120KN; store for 24h, demold, and maintain at 25℃ in an environment with a relative humidity greater than 95% for 28 days, to obtain the anti-cracking epoxy resin concrete.
[0019] Example 3: a preparation method of an anti-cracking epoxy resin concrete, comprising the following steps: Step one: preparation of epoxy resin by using resveratrol: Take 110g of epoxy chloropropane and 45g of resveratrol, heat to 110℃, stir for 3h, add 100mL of 20% sodium hydroxide aqueous solution dropwise, stir for 6h, add 2g of ferric trichloride, stir until the color of the system does not change, cool to 30℃, extract with 100mL of dichloromethane, wash the organic phase, dry, and rotary evaporate to obtain the epoxy resin; Step two: preparation of polyurethane prepolymer by using resveratrol: Take 220g of hydrogen-containing fluorosilicone oil and 0.012g of platinum vinyl siloxane catalyst, pass helium gas, stir, heat to 95℃, add 24g of the epoxy resin prepared in step one, stir for 4h, heat to 152℃, add 0.2g of lithium n-butyl alcohol, 50g of diphenyl methane diisocyanate, stir for 4h, add 12g of 1,2,7,8-diepoxyoctane, stir for 3h, to obtain the polyurethane prepolymer; Step three: preparation of epoxy modified basalt fiber: S1: sodium oleate modified fiber: Take 0.2g of sodium oleate and 300mL of deionized water, stir evenly, heat to 55℃, add 12g of basalt fiber, stir for 2h, filter, wash, and dry to obtain the sodium oleate modified fiber; S2: 3 g of sodium oleate modified fiber, 10 mL of ethanol were taken, and ultrasonic dispersion was performed to obtain a sodium oleate modified fiber solution; 6 g of gamma-glycidoxypropyltrimethoxysilane, 120 mL of ethanol, and 5 mL of deionized water were taken, stirred uniformly, and then the sodium oleate modified fiber solution was added; the temperature was increased to 65°C, and stirring was performed for 2 h; filtration, washing, and drying were performed to obtain epoxy modified basalt fiber; Step four: preparation of anti-cracking epoxy resin concrete: S1: 20 g of polyurethane prepolymer and 80 g of epoxy resin were taken and stirred for 2 h to obtain modified epoxy resin; S2: cement, fine aggregate, coarse aggregate, fly ash, silica fume, modified epoxy resin, epoxy modified basalt fiber, water reducing agent, curing agent, diluent, and deionized water were mixed uniformly to obtain a concrete slurry; The concrete slurry comprises the following ingredients, and the weight fraction is as follows: 110 parts of cement, 125 parts of fine aggregate, 165 parts of coarse aggregate, 35 parts of fly ash, 22 parts of silica fume, 12 parts of modified epoxy resin, 8 parts of epoxy modified basalt fiber, 6 parts of water reducing agent, 4 parts of curing agent, 2.5 parts of diluent, and 24 parts of deionized water; S3: The concrete slurry was taken, poured, and subjected to vibration and pressure molding under a vacuum degree of 0.3 MPa; the pressure was 150 KN, the time was 90 s, the vibration force was 120 KN; storage was performed for 24 h, demolding was performed, and curing was performed at 25°C and a relative humidity of greater than 95% for 28 days to obtain anti-cracking epoxy resin concrete.
[0020] Comparative Example 1: polyurethane prepolymer prepared without adding resveratrol, and the rest was the same as in Example 1: Step one: preparation of epoxy resin with resveratrol: 110 g of epoxy chloropropane and 45 g of resveratrol were taken, the temperature was increased to 109°C, stirring was performed for 2.5 h, 100 mL of 20% sodium hydroxide aqueous solution was added dropwise, stirring was performed for 5.5 h, 2 g of ferric trichloride was added, stirring was performed until the color of the system did not change, the temperature was decreased to 28°C, 100 mL of dichloromethane was added for extraction, the organic phase was washed, dried, and rotary evaporated to obtain epoxy resin; Step two: preparation of polyurethane prepolymer: 220 g of hydrogen-containing fluorosilicone oil and 0.012 g of platinum vinyl siloxane catalyst were taken, helium was passed, stirring was performed, the temperature was increased to 92°C, 24 g of butyl glycidyl ether was added, stirring was performed for 3.5 h, the temperature was increased to 151°C, 0.2 g of lithium n-butyl alcohol and 50 g of diphenylmethane diisocyanate were added, stirring was performed for 3.5 h, 12 g of 1,2,7,8-diepoxyoctane was added, and stirring was performed for 2.5 h to obtain polyurethane prepolymer; Step three: preparation of epoxy modified basalt fiber: S1: sodium oleate modified fiber: Take 0.2g sodium oleate, 300mL deionized water, stir evenly, warm up to 52℃, add 12g basalt fiber, stir for 1.5h, filter, wash, dry, get sodium oleate modified fiber; S2: take 3g sodium oleate modified fiber, 10mL ethanol, ultrasonic dispersion, get sodium oleate modified fiber solution; take 6g of γ-glycidyl ether propyl trimethoxysilane, 120mL ethanol, 5mL deionized water, stir evenly, add sodium oleate modified fiber solution, warm up to 62℃, stir for 1.5h, filter, wash, dry, get epoxy modified basalt fiber; Step four: preparation of anti-cracking epoxy resin concrete: S1: take 20g polyurethane prepolymer, 80g epoxy resin, stir for 1.5h, get modified epoxy resin; S2: take cement, fine aggregate, coarse aggregate, fly ash, silica fume, modified epoxy resin, epoxy modified basalt fiber, water reducing agent, curing agent, diluent, deionized water, mix evenly, get concrete slurry; The concrete slurry includes the following ingredients, in terms of weight fraction: 105 parts of cement, 122 parts of fine aggregate, 160 parts of coarse aggregate, 32 parts of fly ash, 21 parts of silica fume, 11 parts of modified epoxy resin, 7 parts of epoxy modified basalt fiber, 5.5 parts of water reducing agent, 3.5 parts of curing agent, 2.2 parts of diluent, 23 parts of deionized water; S3: take the concrete slurry, pour, perform vibration and pressure forming under a vacuum degree of 0.3MPa, pressure is 150KN, time is 90s, vibration force is 120KN; seal for 24h, demold, cure for 28 days in an environment of 25℃ and relative humidity greater than 95%, get anti-cracking epoxy resin concrete.
[0021] Comparative example 2: prepare epoxy resin without using resveratrol, the rest is the same as example 1: Step one: resveratrol preparation of polyurethane prepolymer: Take 220g hydrogen-containing fluorosilicone oil, 0.012g platinum vinylsiloxane catalyst, pass helium, stir, warm up to 92℃, add 24g epoxy resin E44, stir for 3.5h, warm up to 151℃, add 0.2g n-butoxy lithium, 50g diphenylmethane diisocyanate, stir for 3.5h, add 12g 1,2,7,8-diepoxyoctane, stir for 2.5h, get polyurethane prepolymer; Step two: preparation of epoxy modified basalt fiber: S1: sodium oleate modified fiber: Take 0.2g sodium oleate, 300mL deionized water, stir evenly, heat to 52℃, add 12g basalt fiber, stir for 1.5h, filter, wash, dry, get sodium oleate modified fiber; S2: take 3g sodium oleate modified fiber, 10mL ethanol, ultrasonic dispersion, get sodium oleate modified fiber solution; take 6g of γ-glycidyl ether propyl trimethoxysilane, 120mL ethanol, 5mL deionized water, stir evenly, add sodium oleate modified fiber solution, heat to 62℃, stir for 1.5h, filter, wash, dry, get epoxy modified basalt fiber; Step three: preparation of anti-cracking epoxy resin concrete: S1: take 20g polyurethane prepolymer, 80g epoxy resin E44, stir for 1.5h, get modified epoxy resin; S2: take cement, fine aggregate, coarse aggregate, fly ash, silica fume, modified epoxy resin, epoxy modified basalt fiber, water reducing agent, curing agent, diluent, deionized water, mix evenly, get concrete slurry; The concrete slurry includes the following ingredients, in terms of weight fraction: 105 parts of cement, 122 parts of fine aggregate, 160 parts of coarse aggregate, 32 parts of fly ash, 21 parts of silica fume, 11 parts of modified epoxy resin, 7 parts of epoxy modified basalt fiber, 5.5 parts of water reducing agent, 3.5 parts of curing agent, 2.2 parts of diluent, 23 parts of deionized water; S3: take the concrete slurry, pour, perform vibration and pressure forming under vacuum degree of 0.3MPa, pressure is 150KN, time is 90s, vibration force is 120KN; seal for 24h, demold, cure for 28 days under the environment of 25℃, relative humidity greater than 95%, get anti-cracking epoxy resin concrete.
[0022] Comparative example 3: do not modify basalt fiber with epoxy, the rest is the same as example 1: Step one: preparation of epoxy resin by resveratrol: Take 110g of epoxy chloropropane, 45g of resveratrol, heat to 109℃, stir for 2.5h, add 100mL of 20% sodium hydroxide aqueous solution dropwise, stir for 5.5h, add 2g of ferric chloride, stir until there is no color change in the system, cool to 28℃, extract with 100mL of dichloromethane, wash the organic phase, dry, rotary evaporation, get epoxy resin; Step two: preparation of polyurethane prepolymer by resveratrol: Take 220 g of hydrogen-containing fluorosilicone oil, 0.012 g of platinum vinylsiloxane catalyst, pass helium, stir, heat to 92℃, add 24 g of epoxy resin prepared in step one, stir for 3.5 h, heat to 151℃, add 0.2 g of n-butyllithium, 50 g of diphenylmethane diisocyanate, stir for 3.5 h, add 12 g of 1,2,7,8-epoxyoctane, stir for 2.5 h, to obtain a polyurethane prepolymer; Step three: preparation of sodium oleate modified fiber: Take 0.2 g of sodium oleate, 300 mL of deionized water, stir until uniform, heat to 52℃, add 12 g of basalt fiber, stir for 1.5 h, filter, wash, dry to obtain sodium oleate modified fiber; Step four: preparation of anti-cracking epoxy resin concrete: S1: Take 20 g of polyurethane prepolymer, 80 g of epoxy resin, stir for 1.5 h to obtain modified epoxy resin; S2: Take cement, fine aggregate, coarse aggregate, fly ash, silica fume, modified epoxy resin, sodium oleate modified fiber, water reducing agent, curing agent, diluent, deionized water, mix uniformly to obtain concrete slurry; The concrete slurry includes the following ingredients, in terms of weight fraction: 105 parts of cement, 122 parts of fine aggregate, 160 parts of coarse aggregate, 32 parts of fly ash, 21 parts of silica fume, 11 parts of modified epoxy resin, 7 parts of sodium oleate modified fiber, 5.5 parts of water reducing agent, 3.5 parts of curing agent, 2.2 parts of diluent, 23 parts of deionized water; S3: Take the concrete slurry, pour, and perform vibration and pressure molding under a vacuum degree of 0.3 MPa, with a pressure of 150 KN, a time of 90 s, and a vibration force of 120 KN; seal for 24 h, demold, and cure for 28 days in an environment of 25℃ and a relative humidity greater than 95%, to obtain anti-cracking epoxy resin concrete.
[0023] Experiment: The anti-cracking epoxy resin concrete prepared from Example 1-Example 3, Comparative Example 1-Comparative Example 3 was made into a sample of 150mmx150mmx150mm, and the compressive strength and flexural strength were tested according to GB / T 50081-2019. The sample was intermittently aged in a constant temperature and humidity test chamber with a relative humidity of 85% and a temperature of 55℃, 8 ultraviolet lamps with a rated power of 12W were arranged, the sample was placed in the test chamber for aging for 12h, then the relative humidity in the sample chamber was adjusted to 60% and the temperature was adjusted to 25℃, and the ultraviolet lamps were turned off for 12h, every 24h was a cycle, after 30 cycles, the compressive strength and flexural strength of the sample were tested; a flat test mold of 600mmx400mmx100mm was prepared, a bent wave-shaped stress restraint strip was used to provide restraint, the anti-cracking epoxy resin concrete was coated in the test mold, vibrated for 1min, and the surface was smoothed, and the anti-cracking grade was evaluated under the condition of 25℃ and relative humidity of 65%, and an electric fan was used to continuously blow for 24h, and the wind speed was 8m / s, and the data obtained are shown in Table 1: Table 1
[0024] Conclusion: From the comparison of the data in the table, it can be seen that the polyurethane prepolymer prepared without adding resveratrol in Comparative Example 1 has poor compatibility between the polyurethane prepolymer and the epoxy resin, the mechanical properties of the concrete decrease, and the anti-cracking performance is poor. In Comparative Example 2, the epoxy resin is not prepared using resveratrol, the mechanical properties of the concrete decrease, and the anti-cracking performance is poor. In Comparative Example 3, the basalt fiber is not modified with epoxy, which improves the dispersibility of the basalt fiber in the concrete matrix, thereby improving the anti-cracking property of the concrete. In Examples 1-3 of the present application, resveratrol is used to prepare the epoxy resin, the resveratrol molecule contains a rigid stilbene structure and three phenolic hydroxyl groups, which can improve the mechanical properties of the epoxy resin. The resveratrol is used to prepare the polyurethane prepolymer, and then the polyurethane prepolymer and the epoxy resin are mixed to prepare the modified epoxy resin, chemical crosslinking occurs between the polyurethane prepolymer and the epoxy resin, which improves the crosslinking density of the epoxy resin, improves the compatibility between the two, and improves the mechanical properties of the concrete. In the present application, sodium oleate is used to modify the basalt fiber, which improves the corrosion resistance of the basalt fiber, blocks the invasion of chloride ions, reduces the corrosion of steel bars, and improves the service life of reinforced concrete; however, the modification of sodium oleate improves the hydrophobicity of the basalt fiber, which easily leads to poor dispersibility of the basalt fiber in the concrete matrix and poor anti-cracking performance. The basalt fiber is modified with epoxy in the present application, which improves the dispersibility of the basalt fiber in the concrete matrix, thereby improving the anti-cracking property of the concrete.
[0025] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. The embodiments should therefore be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims
1. A method for preparing crack-resistant epoxy resin concrete, characterized in that: Includes the following steps: Step 1: Take epichlorohydrin and resveratrol, heat to 108-110℃, stir for 2-3 hours, add sodium hydroxide aqueous solution dropwise, stir for 5-6 hours, add ferric chloride, stir until the color of the system does not change, cool to 25-30℃, extract, wash, dry, and rotary evaporate to obtain epoxy resin. Step 2: Take polyurethane prepolymer and epoxy resin, stir for 1-2 hours to obtain modified epoxy resin; Step 3: Take cement, fine aggregate, coarse aggregate, fly ash, silica fume, modified epoxy resin, epoxy modified basalt fiber, water-reducing agent, curing agent, diluent, and deionized water, mix them evenly to obtain concrete slurry; Step 4: Take concrete slurry, pour it, vibrate and press it into shape, seal it for 22-26 hours, demold it, and cure it for 28 days to obtain crack-resistant epoxy resin concrete.
2. The method for preparing crack-resistant epoxy resin concrete according to claim 1, characterized in that: The concrete slurry comprises the following components, by weight: 100-110 parts cement, 120-125 parts fine aggregate, 150-165 parts coarse aggregate, 30-35 parts fly ash, 20-22 parts silica fume, 9-12 parts modified epoxy resin, 6-8 parts epoxy modified basalt fiber, 5-6 parts water-reducing agent, 3-4 parts curing agent, 2-2.5 parts diluent, and 22-24 parts deionized water.
3. The method for preparing crack-resistant epoxy resin concrete according to claim 1, characterized in that: The preparation method of the polyurethane prepolymer is as follows: take hydrofluoric silicone oil and platinum vinylsiloxane catalyst, pass helium gas, stir, heat to 90-95℃, add epoxy resin, stir for 3-4h, heat to 150-152℃, add lithium n-butoxide and diphenylmethane diisocyanate, stir for 3-4h, add 1,2,7,8-diepoxyoctane, stir for 2-3h, and obtain polyurethane prepolymer.
4. The method for preparing crack-resistant epoxy resin concrete according to claim 3, characterized in that: The preparation method of the epoxy resin is as follows: take epichlorohydrin and resveratrol, heat to 108-110℃, stir for 2-3 hours, add sodium hydroxide aqueous solution dropwise, stir for 5-6 hours, add ferric chloride, stir the reaction until the color of the system does not change, cool to 25-30℃, extract, wash, dry and rotary evaporate to obtain epoxy resin.
5. The method for preparing crack-resistant epoxy resin concrete according to claim 2, characterized in that: The preparation method of the epoxy-modified basalt fiber is as follows: take sodium oleate modified fiber and ethanol, and disperse them by ultrasonication to obtain sodium oleate modified fiber solution; take γ-glycidoxypropyltrimethoxysilane, ethanol and deionized water, stir evenly, add sodium oleate modified fiber solution, heat to 60-65℃, stir for 1-2 hours, filter, wash and dry to obtain epoxy-modified basalt fiber.
6. The method for preparing crack-resistant epoxy resin concrete according to claim 5, characterized in that: The method for preparing sodium oleate modified fiber is as follows: take sodium oleate and deionized water, stir evenly, heat to 50-55℃, add basalt fiber, stir for 1-2 hours, filter, wash and dry to obtain sodium oleate modified fiber.
7. The method for preparing crack-resistant epoxy resin concrete according to claim 6, characterized in that: The basalt fibers are 1-3 mm in length and 5-10 µm in diameter.
8. The method for preparing crack-resistant epoxy resin concrete according to claim 1, characterized in that: In step two, the mass ratio of polyurethane prepolymer to epoxy resin is (20-25):(80-100).