A high-performance cement-based repair material and preparation method thereof

Abstract

The invention discloses a high-performance cement-based repair material and a preparation method thereof. The cement-based repair material comprises components A and B. Component A comprises 550-600 parts of cement, 650-700 parts of fly ash, 550-600 parts of quartz sand, 100-150 parts of modified epoxy resin, 350-400 parts of water, and 6-8 parts of a water reducer. Component B comprises 10-20 parts of a synergistic curing agent, 20-30 parts of modified carbon nanotubes, and 5-10 parts of isooctyltriethoxysilane. When components A and B are mixed and added to a cement material to be repaired, the modified epoxy resin is cured to generate stable filling at the gaps. The modified epoxy resin has a comb-like structure, and the synergistic curing agent has a hyperbranched structure. After reacting with the modified epoxy resin, a hyperbranched network can be formed. Molecules of the synergistic curing agent contain dynamic crosslinking of borate and imide bonds, thereby enhancing the mechanical properties of the cement material.

Description

Technical Field

[0001] The present invention relates to the technical field of cement-based repair material preparation, and in particular to a high-performance cement-based repair material and a preparation method thereof. Background Art

[0002] Since its advent, concrete materials have been widely used in various buildings and structures due to their excellent mechanical properties and good economy. Traditional cement-based materials are usually used in the main parts of buildings in engineering construction, such as tunnel bodies, dam bodies of water conservancy projects, and beams and columns of construction projects. The safety and stability of these engineering projects are closely related to the normal lives of the people. However, due to uneven settlement, stress concentration, external erosion and other reasons, the main structure of cement-based materials will suffer from cracks, fractures and surface peeling. In order to solve these problems, cement-based repair materials have been introduced. Traditional cement-based repair materials have low fluidity and short setting time, which cannot fully fill cement gaps, and the mechanical bite force with the repaired area is not high. They will fall off after long-term use, and the mechanical properties of the repaired cement-based materials will be greatly reduced, resulting in poor repair effect. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-performance cement-based repair material and a preparation method thereof, which solves the problems of high fluidity but short setting time of cement-based repair materials at the current stage and poor mechanical properties after curing.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for preparing a high-performance cement-based repair material comprises the following steps:

[0006] Step A1: Epoxy resin E-51 and polyethylene glycol are mixed, stirred at a speed of 120-150 r / min and a temperature of 120-125° C., and trifluoroacetic acid is added to react for 4-6 hours to produce a water-based epoxy resin. The water-based epoxy resin, n-decanoic acid, p-toluenesulfonic acid, and DMF are uniformly mixed, and reacted at a speed of 200-300 r / min and a temperature of 115-120° C. for 4-6 hours to produce a modified epoxy resin.

[0007] Step A2: mixing carbon nanotubes and mixed acid, reacting at a speed of 60-80 r / min and a temperature of 100-110° C. for 3-5 hours, and then washing with deionized water until neutral to obtain carboxylated carbon nanotubes; mixing carboxylated carbon nanotubes, KH550, dicyclohexylcarbodiimide and toluene, and reacting at a speed of 120-150 r / min and a temperature of 25-30° C. for 1-1.5 hours to obtain modified carbon nanotubes;

[0008] Step A3: Weigh the following raw materials in parts by weight: 550-600 parts of cement, 650-700 parts of fly ash, 550-600 parts of quartz sand, 100-150 parts of modified epoxy resin, 350-400 parts of water and 6-8 parts of water reducer, mix them evenly to prepare component A, weigh the following raw materials in parts by weight: 10-20 parts of synergistic curing agent, 20-30 parts of modified carbon nanotubes and 5-10 parts of isooctyltriethoxysilane, mix them evenly to prepare component B, mix components A and B evenly to prepare a high-performance cement-based repair material.

[0009] Furthermore, the molar ratio of the epoxy resin E-51 and polyethylene glycol described in step A1 is 2:1, the amount of trifluoroacetic acid is 1.5‰ of the mass of the epoxy resin E-51, the molar ratio of the alcoholic hydroxyl group on the water-based epoxy resin and n-decanoic acid is 1:1, and the amount of p-toluenesulfonic acid is 1% of the mass of n-decanoic acid.

[0010] Furthermore, the carbon nanotubes and the mixed acid used in step A2 are used in a ratio of 1 g:80 mL. The mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1. The molar ratio of the carboxyl groups on the carboxylated carbon nanotubes, KH550, and dicyclohexylcarbodiimide is 1:1:1.2.

[0011] Furthermore, the synergistic curing agent is prepared by the following steps:

[0012] Step B1: Polyethylene glycol, p-formylbenzoic acid, 4-dimethylaminopyridine and toluene are uniformly mixed and reacted at a speed of 120-150 r / min and a temperature of 115-120°C for 2-3 hours to obtain intermediate 1. Intermediate 1, ethylenediamine, p-toluenesulfonic acid and DMF are mixed and reacted at a speed of 200-300 r / min and a temperature of 50-60°C for 3-5 hours to obtain intermediate 2;

[0013] Step B2: Pentaerythritol, caffeic acid, 4-dimethylaminopyridine and toluene are uniformly mixed, and the mixture is reacted at a speed of 120-150 r / min and a temperature of 115-120°C for 3-5 hours to obtain intermediate 3. Intermediate 3, 4-formylphenylboronic acid, tetraphenylpalladium, triethylamine and DMF are uniformly mixed, and nitrogen protection is introduced, and the mixture is reacted at a speed of 60-80 r / min and a temperature of 60-80°C for 10-15 hours to obtain intermediate 4;

[0014] Step B3: Intermediate 2, intermediate 4, p-toluenesulfonic acid and DMF are mixed, and the reaction is carried out at a speed of 200-300 r / min and a temperature of 50-60°C for 6-8 hours to obtain intermediate 5. Intermediate 5, mercaptoethanol, benzophenone and DMF are mixed uniformly, and the reaction is carried out at a speed of 150-200 r / min, a temperature of 25-30°C and irradiation with 365nm ultraviolet light for 1-1.5 hours to obtain a synergistic curing agent.

[0015] Furthermore, the molar ratio of polyethylene glycol to p-formylbenzoic acid in step B1 is 1:2, the amount of 4-dimethylaminopyridine used is 1% of the mass of p-hydroxybenzoic acid, and the molar ratio of intermediate 1 to ethylenediamine is 1:2.

[0016] Furthermore, the molar ratio of pentaerythritol and caffeic acid in step B2 is 1:4, the amount of 4-dimethylaminopyridine is 1% of the mass of caffeic acid, and the amount ratio of the intermediate 3,4-formylphenylboronic acid, tetraphenylpalladium and triethylamine is 1:1:0.01:1.5.

[0017] Furthermore, the molar ratio of intermediate 2 and intermediate 4 in step B3 is 4:1, the amount of p-toluenesulfonic acid is 1.5% of the mass of intermediate 2, the molar ratio of the double bond on intermediate 5 to mercaptoethanol is 1:1, and the amount of benzophenone is 1‰ of the mass of mercaptoethanol.

[0018] Beneficial effects of the present invention: A high-performance cement-based repair material disclosed in the present invention includes component A and component B, component A includes the following raw materials: cement, fly ash, quartz sand, modified epoxy resin, water and a water reducer, component B includes the following raw materials: a synergistic curing agent, modified carbon nanotubes and isooctyltriethoxysilane, the modified epoxy resin uses epoxy resin E-51 and polyethylene glycol as raw materials, under the action of trifluoroacetic acid, the epoxy group on the epoxy resin E-51 reacts with the hydroxyl group on the polyethylene glycol to prepare a water-based epoxy resin, the water-based epoxy resin is esterified with n-decanoic acid, so that the hydroxyl group on the side chain of the water-based epoxy resin reacts with the carboxyl group on the n-decanoic acid to prepare the modified epoxy resin, the modified carbon nanotubes are treated with a mixed acid so that carboxyl groups are grafted onto the surface to prepare carboxylated carbon nanotubes, the carboxylated carbon nanotubes are reacted with KH550, so that the carboxyl group on the carboxylated carbon nanotubes reacts with the amino group on the KH550 to prepare the modified carbon nanotubes.

[0019] The synergistic curing agent uses polyethylene glycol and p-formylbenzoic acid as raw materials, and the hydroxyl group on the polyethylene glycol reacts with the carboxyl group on the p-formylbenzoic acid to prepare intermediate 1; the intermediate 1 is reacted with ethylenediamine, and the aldehyde group on the intermediate 1 reacts with the amino group to form an amino end capping to prepare intermediate 2; pentaerythritol and caffeic acid are reacted, and the hydroxyl group on the pentaerythritol reacts with the carboxyl group on the caffeic acid to prepare intermediate 3; the intermediate 3 is reacted with 4-formylphenylboronic acid, and the catechol on the intermediate 3 reacts with the boronic acid group on the 4-formylphenylboronic acid to prepare intermediate 4; the intermediate 2 and the intermediate 4 are reacted, and the amino group on the intermediate 2 reacts with the aldehyde group on the intermediate 4 to prepare intermediate 5; the intermediate 5 is reacted with mercaptoethanol, and the double bond on the intermediate 5 reacts with the sulfhydryl group on the mercaptoethanol to prepare the synergistic curing agent.

[0020] When components A and B are mixed and added to the cement material that needs to be repaired, the modified epoxy resin, synergistic curing agent and isooctyltriethoxysilane will flow into the gap, and the modified carbon nanotubes will also be embedded in the wider gap. Under the action of water, isooctyltriethoxysilane and the siloxane on the modified carbon nanotubes are hydrolyzed to produce silanol groups that are grafted to each other and grafted with the hydroxyl groups on the side chains of the modified synergist and the hydroxyl groups on the surface of the cement material. The amino groups in the synergistic curing agent will react with the epoxy groups on the modified epoxy resin, and then solidify, producing stable filling in the gap. The side chains of the modified epoxy resin contain long-chain alkyl groups and the main chain to form a comb-like structure, while the synergistic curing agent is a hyperbranched structure. After reacting with the modified epoxy resin, it can form a hyperbranched grid. The synergistic curing agent molecules contain dynamic crosslinking of borate and imine bonds, thereby enhancing the mechanical properties of the cement material. DETAILED DESCRIPTION

[0021] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0022] Example 1: A method for preparing a high-performance cement-based repair material, comprising the following steps:

[0023] Step A1: Epoxy resin E-51 and polyethylene glycol were mixed, stirred at a speed of 120 r / min and a temperature of 120° C., and trifluoroacetic acid was added to react for 4 hours to prepare a water-based epoxy resin. The water-based epoxy resin, n-decanoic acid, p-toluenesulfonic acid, and DMF were uniformly mixed, and reacted at a speed of 200 r / min and a temperature of 115° C. for 4 hours to prepare a modified epoxy resin.

[0024] Step A2: mixing carbon nanotubes and mixed acid, reacting at a speed of 60 r / min and a temperature of 100° C. for 3 hours, and then washing with deionized water until neutral to obtain carboxylated carbon nanotubes; mixing carboxylated carbon nanotubes, KH550, dicyclohexylcarbodiimide and toluene, and reacting at a speed of 120 r / min and a temperature of 25° C. for 1 hour to obtain modified carbon nanotubes;

[0025] Step A3: Weigh the following raw materials in parts by weight: 550 parts of cement, 650 parts of fly ash, 550 parts of quartz sand, 100 parts of modified epoxy resin, 350 parts of water and 6 parts of water reducer, mix them evenly to prepare component A, weigh the following raw materials in parts by weight: 10 parts of synergistic curing agent, 20 parts of modified carbon nanotubes and 5 parts of isooctyltriethoxysilane, mix them evenly to prepare component B, mix components A and B evenly to prepare a high-performance cement-based repair material.

[0026] The molar ratio of the epoxy resin E-51 and polyethylene glycol described in step A1 is 2:1, the amount of trifluoroacetic acid used is 1.5‰ of the mass of the epoxy resin E-51, the molecular weight of the polyethylene glycol is 1000, the molar ratio of the alcoholic hydroxyl group on the waterborne epoxy resin and n-decanoic acid is 1:1, and the amount of p-toluenesulfonic acid used is 1% of the mass of n-decanoic acid.

[0027] The carbon nanotubes and the mixed acid used in step A2 are used in a ratio of 1 g:80 mL. The mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1. The molar ratio of the carboxyl groups on the carboxylated carbon nanotubes, KH550, and dicyclohexylcarbodiimide is 1:1:1.2.

[0028] The cement described in step A3 is P•O42.5 cement, and the water reducer is polycarboxylic acid high-efficiency water reducing agent with a solid content of 30% and a water reducing efficiency of 35%.

[0029] The synergistic curing agent is prepared by the following steps:

[0030] Step B1: Polyethylene glycol, p-formylbenzoic acid, 4-dimethylaminopyridine and toluene were mixed uniformly, and the mixture was reacted at a speed of 120 r / min and a temperature of 115°C for 2 h to obtain intermediate 1. Intermediate 1, ethylenediamine, p-toluenesulfonic acid and DMF were mixed, and the mixture was reacted at a speed of 200 r / min and a temperature of 50°C for 3 h to obtain intermediate 2;

[0031] Step B2: Pentaerythritol, caffeic acid, 4-dimethylaminopyridine and toluene were mixed uniformly, and the mixture was reacted at a speed of 120 r / min and a temperature of 115°C for 3 hours to obtain intermediate 3. Intermediate 3, 4-formylphenylboronic acid, tetraphenylpalladium, triethylamine and DMF were mixed uniformly, and nitrogen protection was introduced. The mixture was reacted at a speed of 60 r / min and a temperature of 60°C for 10 hours to obtain intermediate 4;

[0032] Step B3: Intermediate 2, intermediate 4, p-toluenesulfonic acid and DMF were mixed, and the reaction was carried out at a speed of 200 r / min and a temperature of 50°C for 6 hours to obtain intermediate 5. Intermediate 5, mercaptoethanol, benzophenone and DMF were mixed uniformly, and the reaction was carried out at a speed of 150 r / min, a temperature of 25°C and irradiation with 365 nm ultraviolet light for 1 hour to obtain a synergistic curing agent.

[0033] The molar ratio of polyethylene glycol to p-formylbenzoic acid in step B1 is 1:2, the amount of 4-dimethylaminopyridine is 1% of the mass of p-hydroxybenzoic acid, the molecular weight of polyethylene glycol is 1000, and the molar ratio of intermediate 1 to ethylenediamine is 1:2.

[0034] The molar ratio of pentaerythritol and caffeic acid in step B2 is 1:4, the amount of 4-dimethylaminopyridine is 1% of the mass of caffeic acid, and the amount ratio of the intermediate 3,4-formylphenylboronic acid, tetraphenylpalladium and triethylamine is 1:1:0.01:1.5.

[0035] The molar ratio of intermediate 2 and intermediate 4 in step B3 is 4:1, the amount of p-toluenesulfonic acid is 1.5% of the mass of intermediate 2, the molar ratio of the double bond on intermediate 5 to mercaptoethanol is 1:1, and the amount of benzophenone is 1‰ of the mass of mercaptoethanol.

[0036] Example 2: A method for preparing a high-performance cement-based repair material, comprising the following steps:

[0037] Step A1: Epoxy resin E-51 and polyethylene glycol were mixed, stirred at a speed of 120 r / min and a temperature of 125° C., and trifluoroacetic acid was added to react for 5 hours to prepare a water-based epoxy resin. The water-based epoxy resin, n-decanoic acid, p-toluenesulfonic acid, and DMF were uniformly mixed, and reacted at a speed of 200 r / min and a temperature of 120° C. for 5 hours to prepare a modified epoxy resin.

[0038] Step A2: mixing carbon nanotubes and mixed acid, reacting at a speed of 60 r / min and a temperature of 105° C. for 4 hours, and then washing with deionized water until neutral to obtain carboxylated carbon nanotubes; mixing carboxylated carbon nanotubes, KH550, dicyclohexylcarbodiimide and toluene, and reacting at a speed of 120 r / min and a temperature of 25° C. for 1.5 hours to obtain modified carbon nanotubes;

[0039] Step A3: Weigh the following raw materials in parts by weight: 580 parts of cement, 680 parts of fly ash, 580 parts of quartz sand, 130 parts of modified epoxy resin, 380 parts of water and 7 parts of water reducer, mix them evenly to prepare component A, weigh the following raw materials in parts by weight: 15 parts of synergistic curing agent, 25 parts of modified carbon nanotubes and 8 parts of isooctyltriethoxysilane, mix them evenly to prepare component B, mix components A and B evenly to prepare a high-performance cement-based repair material.

[0040] The molar ratio of the epoxy resin E-51 and polyethylene glycol described in step A1 is 2:1, the amount of trifluoroacetic acid used is 1.5‰ of the mass of the epoxy resin E-51, the molecular weight of the polyethylene glycol is 1000, the molar ratio of the alcoholic hydroxyl group on the waterborne epoxy resin and n-decanoic acid is 1:1, and the amount of p-toluenesulfonic acid used is 1% of the mass of n-decanoic acid.

[0041] The carbon nanotubes and the mixed acid used in step A2 are used in a ratio of 1 g:80 mL. The mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1. The molar ratio of the carboxyl groups on the carboxylated carbon nanotubes, KH550, and dicyclohexylcarbodiimide is 1:1:1.2.

[0042] The cement described in step A3 is P•O42.5 cement, and the water reducer is polycarboxylic acid high-efficiency water reducing agent with a solid content of 30% and a water reducing efficiency of 35%.

[0043] The synergistic curing agent is prepared by the following steps:

[0044] Step B1: Polyethylene glycol, p-formylbenzoic acid, 4-dimethylaminopyridine and toluene were mixed uniformly, and the mixture was reacted at a speed of 120 r / min and a temperature of 120°C for 2.5 hours to obtain intermediate 1. Intermediate 1, ethylenediamine, p-toluenesulfonic acid and DMF were mixed, and the mixture was reacted at a speed of 200 r / min and a temperature of 55°C for 4 hours to obtain intermediate 2;

[0045] Step B2: Pentaerythritol, caffeic acid, 4-dimethylaminopyridine and toluene were mixed uniformly, and the mixture was reacted at a speed of 150 r / min and a temperature of 115°C for 4 hours to obtain intermediate 3. Intermediate 3, 4-formylphenylboronic acid, tetraphenylpalladium, triethylamine and DMF were mixed uniformly, and nitrogen protection was introduced. The mixture was reacted at a speed of 60 r / min and a temperature of 70°C for 15 hours to obtain intermediate 4;

[0046] Step B3: Intermediate 2, intermediate 4, p-toluenesulfonic acid and DMF were mixed, and the reaction was carried out at a speed of 200 r / min and a temperature of 55°C for 7 hours to obtain intermediate 5. Intermediate 5, mercaptoethanol, benzophenone and DMF were mixed uniformly, and the reaction was carried out at a speed of 150 r / min, a temperature of 30°C and irradiation with 365 nm ultraviolet light for 1.2 hours to obtain a synergistic curing agent.

[0047] The molar ratio of polyethylene glycol to p-formylbenzoic acid in step B1 is 1:2, the amount of 4-dimethylaminopyridine is 1% of the mass of p-hydroxybenzoic acid, the molecular weight of polyethylene glycol is 1000, and the molar ratio of intermediate 1 to ethylenediamine is 1:2.

[0048] The molar ratio of pentaerythritol and caffeic acid in step B2 is 1:4, the amount of 4-dimethylaminopyridine is 1% of the mass of caffeic acid, and the amount ratio of the intermediate 3,4-formylphenylboronic acid, tetraphenylpalladium and triethylamine is 1:1:0.01:1.5.

[0049] The molar ratio of intermediate 2 and intermediate 4 in step B3 is 4:1, the amount of p-toluenesulfonic acid is 1.5% of the mass of intermediate 2, the molar ratio of the double bond on intermediate 5 to mercaptoethanol is 1:1, and the amount of benzophenone is 1‰ of the mass of mercaptoethanol.

[0050] Example 3: A method for preparing a high-performance cement-based repair material, comprising the following steps:

[0051] Step A1: Epoxy resin E-51 and polyethylene glycol were mixed, stirred at a speed of 150 r / min and a temperature of 125° C., and trifluoroacetic acid was added to react for 6 hours to prepare a water-based epoxy resin. The water-based epoxy resin, n-decanoic acid, p-toluenesulfonic acid, and DMF were uniformly mixed, and reacted at a speed of 300 r / min and a temperature of 120° C. for 6 hours to prepare a modified epoxy resin.

[0052] Step A2: mixing carbon nanotubes and mixed acid, reacting at a speed of 80 r / min and a temperature of 110° C. for 5 hours, and then washing with deionized water until neutral to obtain carboxylated carbon nanotubes; mixing carboxylated carbon nanotubes, KH550, dicyclohexylcarbodiimide and toluene, and reacting at a speed of 150 r / min and a temperature of 30° C. for 1.5 hours to obtain modified carbon nanotubes;

[0053] Step A3: Weigh the following raw materials in parts by weight: 600 parts of cement, 700 parts of fly ash, 600 parts of quartz sand, 150 parts of modified epoxy resin, 400 parts of water and 8 parts of water reducer, mix them evenly to prepare component A, weigh the following raw materials in parts by weight: 20 parts of synergistic curing agent, 30 parts of modified carbon nanotubes and 10 parts of isooctyltriethoxysilane, mix them evenly to prepare component B, mix components A and B evenly to prepare a high-performance cement-based repair material.

[0054] The molar ratio of the epoxy resin E-51 and polyethylene glycol described in step A1 is 2:1, the amount of trifluoroacetic acid used is 1.5‰ of the mass of the epoxy resin E-51, the molecular weight of the polyethylene glycol is 1000, the molar ratio of the alcoholic hydroxyl group on the waterborne epoxy resin and n-decanoic acid is 1:1, and the amount of p-toluenesulfonic acid used is 1% of the mass of n-decanoic acid.

[0055] The carbon nanotubes and the mixed acid used in step A2 are used in a ratio of 1 g:80 mL. The mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1. The molar ratio of the carboxyl groups on the carboxylated carbon nanotubes, KH550, and dicyclohexylcarbodiimide is 1:1:1.2.

[0056] The cement described in step A3 is P•O42.5 cement, and the water reducer is polycarboxylic acid high-efficiency water reducing agent with a solid content of 30% and a water reducing efficiency of 35%.

[0057] The synergistic curing agent is prepared by the following steps:

[0058] Step B1: Polyethylene glycol, p-formylbenzoic acid, 4-dimethylaminopyridine and toluene were mixed uniformly, and the mixture was reacted at a speed of 150 r / min and a temperature of 120°C for 3 hours to obtain intermediate 1. Intermediate 1, ethylenediamine, p-toluenesulfonic acid and DMF were mixed, and the mixture was reacted at a speed of 300 r / min and a temperature of 60°C for 5 hours to obtain intermediate 2;

[0059] Step B2: Pentaerythritol, caffeic acid, 4-dimethylaminopyridine and toluene were mixed uniformly, and the mixture was reacted at a speed of 150 r / min and a temperature of 120°C for 5 hours to obtain intermediate 3. Intermediate 3, 4-formylphenylboronic acid, tetraphenylpalladium, triethylamine and DMF were mixed uniformly, and nitrogen protection was introduced. The mixture was reacted at a speed of 80 r / min and a temperature of 80°C for 15 hours to obtain intermediate 4;

[0060] Step B3: Intermediate 2, intermediate 4, p-toluenesulfonic acid and DMF were mixed and reacted at a speed of 300 r / min and a temperature of 60°C for 8 hours to obtain intermediate 5. Intermediate 5, mercaptoethanol, benzophenone and DMF were mixed uniformly and reacted at a speed of 200 r / min, a temperature of 30°C and irradiation with 365 nm ultraviolet light for 1-1.5 hours to obtain a synergistic curing agent.

[0061] The molar ratio of polyethylene glycol to p-formylbenzoic acid in step B1 is 1:2, the amount of 4-dimethylaminopyridine is 1% of the mass of p-hydroxybenzoic acid, the molecular weight of polyethylene glycol is 1000, and the molar ratio of intermediate 1 to ethylenediamine is 1:2.

[0062] The molar ratio of pentaerythritol and caffeic acid in step B2 is 1:4, the amount of 4-dimethylaminopyridine is 1% of the mass of caffeic acid, and the amount ratio of the intermediate 3,4-formylphenylboronic acid, tetraphenylpalladium and triethylamine is 1:1:0.01:1.5.

[0063] The molar ratio of intermediate 2 and intermediate 4 in step B3 is 4:1, the amount of p-toluenesulfonic acid is 1.5% of the mass of intermediate 2, the molar ratio of the double bond on intermediate 5 to mercaptoethanol is 1:1, and the amount of benzophenone is 1‰ of the mass of mercaptoethanol.

[0064] Comparative Example 1: Compared with Example 1, this comparative example uses carbon nanotubes instead of modified carbon nanotubes, and the remaining steps are the same.

[0065] Comparative Example 2: Compared with Example 1, this comparative example uses aqueous epoxy resin instead of modified epoxy resin, and the remaining steps are the same.

[0066] Comparative Example 3: Compared with Example 1, this comparative example uses ethylene glycol instead of pentaerythritol, and the remaining steps are the same.

[0067] Comparative Example 4: Compared with Example 1, this comparative example uses intermediate 5 instead of the synergistic curing agent, and the remaining steps are the same.

[0068] The cement-based repair materials prepared in Examples 1-3 and Comparative Examples 1-4 were tested for fluidity according to the standard of JC / T1083-2008, for setting time according to the standard of GB / T1346-2011, and for compressive strength according to the standard of GB / T17671-2021. The test results are shown in Table 1 below.

[0069]

[0070] It can be seen from the above table that the present application has excellent fluidity, a long setting time, and better mechanical properties.

[0071] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a high-performance cement-based repair material, characterized by: The specific steps include: Step A1: Epoxy resin E-51 and polyethylene glycol are mixed and stirred, and trifluoroacetic acid is added to react to prepare a water-based epoxy resin. The water-based epoxy resin, n-decanoic acid, p-toluenesulfonic acid, and DMF are mixed and reacted to prepare a modified epoxy resin; Step A2: After the carbon nanotubes and the mixed acid are mixed and reacted, the mixture is washed with deionized water until neutral to obtain carboxylated carbon nanotubes; and the carboxylated carbon nanotubes, KH550, dicyclohexylcarbodiimide and toluene are mixed and reacted to obtain modified carbon nanotubes; Step A3: Weigh the following raw materials in parts by weight: 550-600 parts of cement, 650-700 parts of fly ash, 550-600 parts of quartz sand, 100-150 parts of modified epoxy resin, 350-400 parts of water, and 6-8 parts of water reducer, and mix them evenly to prepare component A. Weigh the following raw materials in parts by weight: 10-20 parts of synergistic curing agent, 20-30 parts of modified carbon nanotubes, and 5-10 parts of isooctyltriethoxysilane, and mix them evenly to prepare component B. Component A and component B are evenly mixed to prepare a high-performance cement-based repair material. The synergistic curing agent is prepared by the following steps: Step B1: polyethylene glycol, p-formylbenzoic acid, 4-dimethylaminopyridine and toluene are mixed and reacted to obtain intermediate 1, and intermediate 1, ethylenediamine, p-toluenesulfonic acid and DMF are mixed and reacted to obtain intermediate 2; Step B2: Pentaerythritol, caffeic acid, 4-dimethylaminopyridine and toluene are mixed to react to obtain intermediate 3, and intermediate 3, 4-formylphenylboronic acid, tetraphenylpalladium, triethylamine and DMF are mixed uniformly, and nitrogen protection is introduced to react to obtain intermediate 4; Step B3: Intermediate 2, intermediate 4, p-toluenesulfonic acid and DMF are mixed and reacted to obtain intermediate 5, and intermediate 5, mercaptoethanol, benzophenone and DMF are mixed and reacted to obtain a synergistic curing agent.

2. The method for preparing a high-performance cement-based repair material according to claim 1, characterized in that: The molar ratio of the epoxy resin E-51 and polyethylene glycol described in step A1 is 2:1, and the molar ratio of the alcoholic hydroxyl group on the waterborne epoxy resin and n-decanoic acid is 1:

1.

3. The method for preparing a high-performance cement-based repair material according to claim 1, characterized in that: The carbon nanotubes and the mixed acid used in step A2 are used in a ratio of 1 g:80 mL. The mixed acid is prepared by mixing concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:

1. The molar ratio of the carboxyl groups on the carboxylated carbon nanotubes, KH550, and dicyclohexylcarbodiimide is 1:1:1.

2.

4. The method for preparing a high-performance cement-based repair material according to claim 1, characterized in that: The molar ratio of polyethylene glycol to p-formylbenzoic acid in step B1 is 1:2, and the molar ratio of intermediate 1 to ethylenediamine is 1:

2.

5. The method for preparing a high-performance cement-based repair material according to claim 1, characterized in that: The molar ratio of pentaerythritol and caffeic acid in step B2 is 1:4, and the usage ratio of the intermediate 3,4-formylphenylboronic acid, tetraphenylpalladium and triethylamine is 1:1:0.01:1.

5.

6. The method for preparing a high-performance cement-based repair material according to claim 1, characterized in that: The molar ratio of intermediate 2 to intermediate 4 in step B3 is 4:1, and the molar ratio of the double bond on intermediate 5 to mercaptoethanol is 1:

1.

7. A high-performance cement-based repair material, characterized by: Prepared according to any one of claims 1 to 6.

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