Preparation method of anti-cracking waterproofing agent suitable for long-distance water tunnel lining in cold regions

Abstract

The present application relates to a kind of preparation methods of anti-cracking waterproofing agent suitable for cold region long distance water tunnel lining, belong to concrete additive technical field.The present application grafts hydrophobic organosilicon segment to the surface of nano-aluminum oxide, and the reaction of thiol-modified polypropylene fiber and thiol-modified chondrites fibrite fiber is carried out through the epoxy group of the surface grafting of nano-aluminum oxide, to obtain aluminum oxide fiber composite, can nano-aluminum oxide, chondrites fibrite fiber and polypropylene fiber are bonded together by hydrophobic long chain, improve the binding force between three.Using the anti-cracking waterproofing agent including aluminum oxide fiber composite in concrete, long-chain silicon oil segment between nano-aluminum oxide, chondrites fibrite fiber and polypropylene fiber and the tannin acid polymer on the surface of polypropylene fiber can give aluminum oxide fiber composite certain elasticity, improve the anti-cracking property and frost resistance grade of concrete.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a crack-resistant waterproof agent suitable for lining of a long-distance water conveying tunnel in a cold region, and belongs to the technical field of concrete additives. BACKGROUND

[0002] Concrete is the most widely used building material in the field of civil engineering. In recent years, with the construction of super-long structures, underground structures and mass concrete structures, the use of concrete has further increased. Imperfect waterproof and drainage systems and the presence of concrete cracks can cause groundwater to come into contact with engineering concrete, resulting in leakage problems, which seriously interfere with the normal operation of the project. In order to improve the strength of concrete, a large amount of admixtures are usually added to concrete, which greatly reduces the water-cement ratio of concrete, and further makes the free water in concrete become less and less, causing the concrete to be prone to plastic shrinkage and surface cracks.

[0003] In order to improve the waterproof and impermeable performance of concrete, the current method is to add fibers, waterproof agents and expanding agents to the concrete. The fibers in the concrete can interlock and interconnect to form a fiber mesh, increase the adsorption force between the concrete aggregates, significantly improve the crack resistance of the concrete, and reduce the plastic shrinkage cracks. The waterproof additive can significantly optimize the waterproofness and resistance to penetration of the concrete. The expansion agent can improve the self-expanding property of the concrete and reduce the micro-cracks caused by shrinkage. For example, Chinese patent document CN109053023A discloses an expansion fiber crack-resistant waterproof agent, which is composed of the following raw materials in mass percentage: anti-cracking expansion agent 10-30%, microbead powder 20-40%, coal gangue 30-45%, modified basalt fiber 0.5-5%, cellulose graft shell poly 0.4-2%, early strength agent 1-2%, water reducing agent 0.5-1.0%, and defoaming agent 0.1-0.2%. The expansion fiber crack-resistant waterproof agent can play a role in superimposed shrinkage compensation in concrete, effectively avoid micro-cracks caused by different reasons at different ages of concrete, prevent and inhibit the generation and development of cracks, and can improve the flexural strength, impermeability and frost resistance of concrete. However, with the increasingly harsh environment of concrete, such as the long-distance water conveying tunnel project in the cold region with low temperature all year round, the expansion fiber crack-resistant waterproof agent cannot meet the use requirements.

[0004] Therefore, it is urgent to develop a crack-resistant waterproof agent to further improve the crack-resistant waterproof and impermeable and frost-resistant performance of concrete to meet the use requirements of lining of a long-distance water conveying tunnel in a cold region. SUMMARY

[0005] The application aims to provide a preparation method of a crack-resistant waterproof agent suitable for lining of a long-distance water conveying tunnel in a cold region, to solve the problem of deviation of the crack-resistant waterproof and impermeable and frost-resistant performance of concrete.

[0006] The application provides a preparation method of a crack-resistant waterproof agent for long-distance water tunnel lining in cold regions, and comprises the following steps: uniformly mixing calcium sulfate, calcium oxide, iron oxide and an aluminum oxide fiber compound to obtain the crack-resistant waterproof agent for long-distance water tunnel lining in cold regions; the mass ratio of the calcium sulfate, the calcium oxide, the iron oxide and the aluminum oxide fiber compound is 30-40:5-8:3-4:10-15; and the preparation method of the aluminum oxide fiber compound is as follows:

[0007] (1) reacting end double bond end epoxy group silicone oil and triethoxysilane to obtain epoxy silicone oil modified silane coupling agent; the structure of the end double bond end epoxy group silicone oil is as follows:

[0008] ;

[0009] The structure of the epoxy silicone oil modified silane coupling agent is as follows:

[0010] ;

[0011] (2) reacting the epoxy silicone oil modified silane coupling agent and nano-alumina to obtain epoxy silicone oil modified nano-alumina; the average particle size of the nano-alumina is 40-70 nm;

[0012] (3) reacting 3-mercaptopropyl triethoxysilane and flogopite fiber to obtain mercapto modified inorganic fiber;

[0013] (4) reacting tannic acid and polypropylene fiber to obtain phenolic compound modified polypropylene fiber; then, reacting the phenolic compound modified polypropylene fiber and 3-mercaptopropyl triethoxysilane to obtain mercapto modified polypropylene fiber;

[0014] (5) reacting the epoxy silicone oil modified nano-alumina, the mercapto modified inorganic fiber and the mercapto modified polypropylene fiber to obtain an aluminum oxide fiber compound; the mass ratio of the mercapto modified inorganic fiber and the mercapto modified polypropylene fiber is 3-5:2-3, and the ratio of the sum of the molar amounts of mercapto groups in the mercapto modified inorganic fiber and the mercapto modified polypropylene fiber to the molar amount of epoxy groups in the epoxy silicone oil modified nano-alumina is 1.2-1.4:1.

[0015] Preferably, the end double bond end epoxy group silicone oil is prepared by mixing and reacting end epoxy group silicone oil and acrylic acid under the catalysis of tetrabutylammonium bromide at 90-100 DEG C for 5-7 h; the molar ratio of the epoxy groups in the end epoxy group silicone oil to the acrylic acid is 2:1.

[0016] Preferably, the number average molecular weight of the end epoxy group silicone oil is 1500-3000.

[0017] Preferably, the end double bond end epoxy group silicone oil and triethoxysilane are reacted with chloroplatinic acid as catalyst and p-hydroxyanisole as polymerization inhibitor, the reaction temperature is 85-95℃, the reaction time is 6-8h; the molar ratio of double bond in the end double bond end epoxy group silicone oil to triethoxysilane is 1:1.02-1.05, the mass of p-hydroxyanisole is 0.2-0.5% of the mass of the end double bond end epoxy group silicone oil, and the mass of chloroplatinic acid is 0.007-0.01% of the mass of the end double bond end epoxy group silicone oil.

[0018] Preferably, the method for reacting the epoxy silicone oil modified silane coupling agent and nano alumina is as follows: the epoxy silicone oil modified silane coupling agent, ethanol and water are mixed in a mass ratio of 10:30-40:5-8, then the pH is adjusted to 4-5 with hydrochloric acid, and then the ethanol dispersion liquid of nano alumina with a mass fraction of 15-20% is added, and the mixture is heated to 70-80℃ and mixed for 7-10h to obtain the epoxy silicone oil modified nano alumina; the mass ratio of the epoxy silicone oil modified silane coupling agent to nano alumina is 10:2-3.

[0019] Preferably, the method for reacting the 3-mercaptopropyl triethoxysilane and the serpentine fiber is as follows: the 3-mercaptopropyl triethoxysilane, ethanol and water are mixed in a mass ratio of 7:30-40:5-8, then the pH is adjusted to 4-5 with hydrochloric acid, and then the ethanol dispersion liquid of the serpentine fiber with a mass fraction of 0.4-0.7% is added, and the mixture is heated to 70-80℃ and mixed for 5-8h to obtain the mercapto modified inorganic fiber; the mass ratio of the 3-mercaptopropyl triethoxysilane to the serpentine fiber is 2-3:1, the average length of the serpentine fiber is 7-10μm, and the average diameter is 30-50nm.

[0020] Preferably, the method for reacting the tannic acid and the polypropylene fiber is as follows: the trimethylol aminomethyl methane, sodium chloride, tannic acid and water are mixed in a mass ratio of 0.5:2.5:0.5:150-180 to obtain a mixed solution, then the pH of the mixed solution is adjusted to 8-9 to obtain a modified solution, and then the polypropylene fiber is immersed in the modified solution and subjected to oscillation reaction at a speed of 200-250r / min for 24-30h to obtain the phenolic compound modified polypropylene fiber.

[0021] Preferably, the average diameter of the polypropylene fiber is 30-50μm, and the average length is 15-20mm.

[0022] Preferably, the method for reacting the phenolic compound modified polypropylene fiber and 3-mercaptopropyl triethoxysilane is as follows: 3-mercaptopropyl triethoxysilane, ethanol and water are mixed in a mass ratio of 8:30-40:5-8, then the pH is adjusted to 4-5 with hydrochloric acid, an ethanol dispersion of the phenolic compound modified polypropylene fiber with a mass fraction of 5-8% is added, heated to 70-80°C, mixed and reacted for 5-8 hours to obtain the mercapto-modified polypropylene fiber; the mass ratio of 3-mercaptopropyl triethoxysilane to the phenolic compound modified polypropylene fiber is 3-5:1.

[0023] Preferably, when the epoxy silicone oil modified nano-alumina, the mercapto-modified inorganic fiber and the mercapto-modified polypropylene fiber are reacted, tetrabutylammonium fluoride is used as a catalyst, the reaction temperature is 50-60°C, the reaction time is 6-8 hours, and the mass of tetrabutylammonium fluoride is 0.05-0.08% of the mass of the epoxy silicone oil modified nano-alumina.

[0024] Compared with the prior art, the present application has the following advantages:

[0025] (1) In the present application, the hydrophobic silicone chain segment is grafted to the surface of nano-alumina, and the mercapto-modified serpentine fiber and the mercapto-modified polypropylene fiber are reacted through the mercapto group and the epoxy group grafted on the surface of nano-alumina to obtain an alumina fiber composite. The nano-alumina, the serpentine fiber and the polypropylene fiber are bonded together through the hydrophobic long chain, thereby improving the bonding force among the three. When the anti-cracking waterproof agent including the alumina fiber composite is used in concrete, the silicon oil molecular chain connecting the nano-alumina, the serpentine fiber and the polypropylene fiber contains a large number of hydrophilic hydroxyl groups. The lipophilic silicone chain segment and the hydrophilic hydroxyl group cooperate with each other to form a good surface active system, thereby improving the dispersibility of the alumina fiber composite in the aqueous concrete slurry. The serpentine fiber and the polypropylene fiber form a branched network structure with the nano-alumina as the center core point, thereby improving the dispersion uniformity of the serpentine fiber and the polypropylene fiber, avoiding the disorder, intersection and entanglement of linear fibers, improving the contact area with the concrete, and further improving the support to the main structure of the concrete. When an external force is applied, the cracking of the concrete is reduced.

[0026] (2) Since the nano-alumina, the fibrous serpentine fiber and the polypropylene fiber are bonded together by chemical bonds, the three can form a stable anchoring structure, improve the tensile strength, the bending strength, the waterproof performance and the maximum water permeation pressure of the concrete; the hydrophobic long chain among the three can further improve the waterproof performance and the maximum water permeation pressure of the concrete. In addition, the tannin acid polymer deposited on the surface of the polypropylene fiber can improve the wettability and dispersibility of the oleophilic polypropylene fiber in the concrete slurry, and can improve the surface roughness of the polypropylene fiber, improve the embedding strength and affinity of the polypropylene fiber with the concrete, and further improve the strength, waterproofness and impermeability of the concrete. Finally, the long-chain silicone oil segment between the nano-alumina, the fibrous serpentine fiber and the polypropylene fiber and the tannin acid polymer on the surface of the polypropylene fiber can impart a certain elasticity to the alumina fiber composite, improve the crack resistance and frost resistance grade of the concrete. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The nuclear magnetic hydrogen spectrum of the end double bond end epoxy group silicone oil prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0028] The following examples are intended to further illustrate the content of the present application, but not to limit the protection scope of the present application.

[0029] Example 1

[0030] The preparation method of the anti-cracking waterproof agent suitable for the lining of long-distance water tunnel in cold regions of the present embodiment comprises the following steps:

[0031] (1) Put the end epoxy group silicone oil, acrylic acid, tetrabutylammonium bromide and acetone into a reaction kettle, heat to 90℃, stir for 5h, reduce to room temperature, remove acetone by reduced pressure distillation, obtain a concentrated liquid, purify the concentrated liquid by column chromatography, obtain the end double bond end epoxy group silicone oil; wherein the molar ratio of the epoxy group in the end epoxy group silicone oil and the acrylic acid is 2:1, the mass of the tetrabutylammonium bromide is 0.5% of the mass of the end epoxy group silicone oil, the mass of the acetone is 40% of the mass of the end epoxy group silicone oil, the eluent used in the column chromatography purification is composed of methanol and dichloromethane with a volume ratio of 0.5:25; the number average molecular weight of the end epoxy group silicone oil is 1500, and the structure is as follows: ;

[0032] The nuclear magnetic hydrogen spectrum of the end double bond end epoxy group silicone oil is shown in Figure 1 , and the structure is as follows: .

[0033] (2) Put end double bond end epoxy group silicone oil, p-hydroxyanisole, chloroplatinic acid and toluene into a reaction kettle, stir uniformly, introduce nitrogen into the reaction kettle, heat and control the temperature of the material in the reaction kettle at 85℃, add triethoxysilane into the reaction kettle under stirring, after the addition is completed, stir for 6h, remove toluene by distillation under reduced pressure, to obtain an epoxy silicone oil modified silane coupling agent; wherein the molar ratio of double bond in the end double bond end epoxy group silicone oil to triethoxysilane is 1:1.02, the mass of p-hydroxyanisole is 0.2% of the mass of the end double bond end epoxy group silicone oil, the mass of chloroplatinic acid is 0.007% of the mass of the end double bond end epoxy group silicone oil, and the mass of toluene is 40% of the mass of the end double bond end epoxy group silicone oil; the structure of the epoxy silicone oil modified silane coupling agent is as follows: .

[0034] (3) Put the epoxy silicone oil modified silane coupling agent, ethanol and deionized water with a mass ratio of 10:30:5 into a reaction kettle, then add hydrochloric acid into the reaction kettle, adjust the pH of the material in the reaction kettle to 4, then add an ethanol dispersion solution of nano-aluminum oxide with a mass fraction of 15% into the reaction kettle, heat the material in the reaction kettle to 70℃, and stir for reflux reaction for 7h, then filter, wash the filter cake with ethanol, and obtain an epoxy silicone oil modified nano-aluminum oxide; wherein the mass ratio of the epoxy silicone oil modified silane coupling agent to the nano-aluminum oxide is 10:2, and the average particle size of the nano-aluminum oxide is 40nm.

[0035] (4) Put 3-mercaptopropyl triethoxysilane, ethanol and deionized water with a mass ratio of 7:30:5 into a reaction kettle, then add hydrochloric acid into the reaction kettle, adjust the pH of the material in the reaction kettle to 4, then add an ethanol dispersion solution of fibrous serpentine fiber with a mass fraction of 0.4% into the reaction kettle, heat the material in the reaction kettle to 70℃, and stir for reflux reaction for 5h, then filter, wash the filter cake with ethanol, and obtain a mercapto modified inorganic fiber; wherein the mass ratio of 3-mercaptopropyl triethoxysilane to fibrous serpentine fiber is 2:1, the average length of the fibrous serpentine fiber is 7μm, and the average diameter is 30nm.

[0036] (5) Put trimethylol aminomethyl methane, sodium chloride, tannic acid and water with a mass ratio of 0.5:2.5:0.5:150 into a stirring kettle, stir until the solids are fully dissolved to obtain a mixed solution, adjust the pH of the mixed solution to 8 by using 0.1mol / L hydrochloric acid to obtain a modified solution; immerse polypropylene fibers in the modified solution, place them on a shaking bed oscillator for oscillation, the rotation speed is 200r / min, after oscillation for 24h, take out the polypropylene fibers, wash them with deionized water, and dry to obtain phenolic compound modified polypropylene fibers; the average diameter of the polypropylene fibers is 30μm, and the average length is 15mm.

[0037] (6) 3-mercaptopropyl triethoxysilane, ethanol and deionized water with a mass ratio of 8:30:5 are added into a reaction kettle, hydrochloric acid is further added into the reaction kettle, the pH of the materials in the reaction kettle is adjusted to 4, then the ethanol dispersion liquid of the phenolic compound modified polypropylene fiber with a mass fraction of 5% is added into the reaction kettle, the materials in the reaction kettle are heated to 70 DEG C, reflux stirring reaction is carried out for 5 hours, filtration is carried out, the filter cake is washed with ethanol, and the mercapto-modified polypropylene fiber is obtained; wherein the mass ratio of 3-mercaptopropyl triethoxysilane and the phenolic compound modified polypropylene fiber is 3:1.

[0038] (7) The epoxy silicone oil modified nano alumina, the mercapto-modified inorganic fiber, the mercapto-modified polypropylene fiber and ethanol are ultrasonically dispersed to obtain a mixed liquid, then tetrabutylammonium fluoride is added into the mixed liquid, stirring is carried out at room temperature for 25 min, then heating is carried out to 50 DEG C, stirring reaction is carried out for 6 h, ethanol is removed by distillation under reduced pressure, and the alumina fiber composite is obtained after drying; wherein the mass ratio of the mercapto-modified inorganic fiber and the mercapto-modified polypropylene fiber is 3:2, the ratio of the sum of the molar amounts of the mercapto groups in the mercapto-modified inorganic fiber and the mercapto-modified polypropylene fiber to the molar amount of the epoxy groups in the epoxy silicone oil modified nano alumina is 1.2:1, the mass of tetrabutylammonium fluoride is 0.05% of the mass of the epoxy silicone oil modified nano alumina, and the mass ratio of the epoxy silicone oil modified nano alumina and ethanol is 1:3.

[0039] (8) The calcium sulfate, calcium oxide, iron oxide and the alumina fiber composite are uniformly stirred to obtain the anti-cracking waterproof agent suitable for the lining of long-distance water conveying tunnels in cold regions; wherein the mass ratio of the calcium sulfate, calcium oxide, iron oxide and the alumina fiber composite is 30:5:3:10.

[0040] Example 2

[0041] The preparation method of the anti-cracking waterproof agent suitable for the lining of long-distance water conveying tunnels in cold regions in the example comprises the following steps:

[0042] (1) The epoxy-terminated silicone oil, acrylic acid, tetrabutylammonium bromide and acetone are added into a reaction kettle, heating is carried out to 95 DEG C, stirring reaction is carried out for 6 h, the temperature is reduced to room temperature, acetone is removed by distillation under reduced pressure, a concentrated liquid is obtained, column chromatography purification is carried out on the concentrated liquid, and the epoxy-terminated silicone oil with double bonds is obtained; wherein the molar ratio of the epoxy groups in the epoxy-terminated silicone oil to the acrylic acid is 2:1, the mass of tetrabutylammonium bromide is 0.8% of the mass of the epoxy-terminated silicone oil, the mass of acetone is 45% of the mass of the epoxy-terminated silicone oil, the eluent used in column chromatography purification is composed of methanol and dichloromethane with a volume ratio of 0.5:25; the number average molecular weight of the epoxy-terminated silicone oil is 2000, and the structure is as follows: ;

[0043] The structure of the epoxy-terminated silicone oil with double bonds is as follows: .

[0044] (2) Put end double bond end epoxy group silicone oil, p-hydroxyanisole, chloroplatinic acid and toluene into the reaction kettle, stir uniformly, introduce nitrogen into the reaction kettle, heat and control the temperature of the material in the reaction kettle at 90℃, add triethoxysilane into the reaction kettle under stirring, after the end of the drop, stir for 7h, remove toluene by reduced pressure distillation, obtain epoxy silicone oil modified silane coupling agent; wherein the molar ratio of double bond in end double bond end epoxy group silicone oil and triethoxysilane is 1:1.03, the mass of p-hydroxyanisole is 0.3% of the mass of end double bond end epoxy group silicone oil, the mass of chloroplatinic acid is 0.009% of the mass of end double bond end epoxy group silicone oil, the mass of toluene is 45% of the mass of end double bond end epoxy group silicone oil; the structure of epoxy silicone oil modified silane coupling agent is as follows: .

[0045] (3) Put epoxy silicone oil modified silane coupling agent, ethanol and deionized water with a mass ratio of 10:35:7 into the reaction kettle, then add hydrochloric acid into the reaction kettle, adjust the pH of the material in the reaction kettle to 4.5, then add 17% mass fraction of nano alumina ethanol dispersion into the reaction kettle, heat the material in the reaction kettle to 75℃, stir and reflux for 8h, filter, wash the filter cake with ethanol, obtain epoxy silicone oil modified nano alumina; wherein the mass ratio of epoxy silicone oil modified silane coupling agent and nano alumina is 10:2.5, the average particle size of nano alumina is 55nm.

[0046] (4) Put 3-mercaptopropyl triethoxysilane, ethanol and deionized water with a mass ratio of 7:35:7 into the reaction kettle, then add hydrochloric acid into the reaction kettle, adjust the pH of the material in the reaction kettle to 4.5, then add 0.6% mass fraction of chrysotile fiber ethanol dispersion into the reaction kettle, heat the material in the reaction kettle to 75℃, stir and reflux for 7h, filter, wash the filter cake with ethanol, obtain mercapto modified inorganic fiber; wherein the mass ratio of 3-mercaptopropyl triethoxysilane and chrysotile fiber is 2.5:1, the average length of chrysotile fiber is 8μm, and the average diameter is 40nm.

[0047] (5) Put trimethylol aminomethyl methane, sodium chloride, tannic acid and water with a mass ratio of 0.5:2.5:0.5:170 into the stirring kettle, stir until the solids are fully dissolved, obtain a mixed solution, adjust the pH of the mixed solution to 8 with 0.1mol / L hydrochloric acid, obtain a modified solution; immerse the polypropylene fiber in the modified solution, place it on a shaking bed oscillator for oscillation, the speed is 220r / min, after oscillation for 27h, take out the polypropylene fiber, wash it with deionized water, dry to obtain phenolic compound modified polypropylene fiber; the average diameter of the polypropylene fiber is 40μm, and the average length is 18mm.

[0048] (6) 3-mercaptopropyl triethoxysilane, ethanol and deionized water with a mass ratio of 8:35:7 are added into a reaction kettle, hydrochloric acid is further added into the reaction kettle, the pH of the materials in the reaction kettle is adjusted to 4.5, then the phenolic compound modified polypropylene fiber ethanol dispersion liquid with a mass fraction of 7% is added into the reaction kettle, the materials in the reaction kettle are heated to 75 ℃, and reflux reaction is carried out for 6 h under stirring, then filtration is performed, the filter cake is washed with ethanol, and mercapto-modified polypropylene fiber is obtained; wherein the mass ratio of 3-mercaptopropyl triethoxysilane and the phenolic compound modified polypropylene fiber is 4:1.

[0049] (7) The epoxy silicone oil modified nano alumina, the mercapto-modified inorganic fiber, the mercapto-modified polypropylene fiber and ethanol are ultrasonically dispersed to obtain a mixed liquid, then tetrabutylammonium fluoride is added into the mixed liquid, stirring is performed at room temperature for 30 min, then heating is performed to 55 ℃, and reaction is performed for 7 h under stirring, then ethanol is removed by distillation under reduced pressure, and the alumina fiber composite is obtained after drying; wherein the mass ratio of the mercapto-modified inorganic fiber and the mercapto-modified polypropylene fiber is 4:2.5, the ratio of the sum of the molar amounts of the mercapto groups in the mercapto-modified inorganic fiber and the mercapto-modified polypropylene fiber to the molar amount of the epoxy groups in the epoxy silicone oil modified nano alumina is 1.3:1, the mass of tetrabutylammonium fluoride is 0.06% of the mass of the epoxy silicone oil modified nano alumina, and the mass ratio of the epoxy silicone oil modified nano alumina and ethanol is 1:4.

[0050] (8) The calcium sulfate, calcium oxide, iron oxide and the alumina fiber composite are uniformly stirred to obtain a crack-resistant waterproofing agent suitable for lining of long-distance water conveying tunnels in cold regions; wherein the mass ratio of the calcium sulfate, the calcium oxide, the iron oxide and the alumina fiber composite is 35:7:3.5:12.

[0051] Example 3

[0052] The preparation method of the crack-resistant waterproofing agent suitable for lining of long-distance water conveying tunnels in cold regions in the example comprises the following steps:

[0053] (1) The terminal epoxy silicone oil, acrylic acid, tetrabutylammonium bromide and acetone are added into a reaction kettle, heating is performed to 100 ℃, reaction is performed for 7 h under stirring, then the temperature is reduced to room temperature, acetone is removed by distillation under reduced pressure, a concentrated liquid is obtained, the concentrated liquid is purified by column chromatography, and terminal double bond terminal epoxy silicone oil is obtained; wherein the molar ratio of the epoxy groups in the terminal epoxy silicone oil to the acrylic acid is 2:1, the mass of tetrabutylammonium bromide is 1% of the mass of the terminal epoxy silicone oil, the mass of acetone is 50% of the mass of the terminal epoxy silicone oil, the eluent used in column chromatography purification is composed of methanol and dichloromethane with a volume ratio of 0.5:25; the number average molecular weight of the terminal epoxy silicone oil is 3000, and the structure is as follows: ;

[0054] The structure of the terminal double bond terminal epoxy silicone oil is as follows: .

[0055] (2) Put end double bond end epoxy group silicone oil, p-hydroxyanisole, chloroplatinic acid and toluene into a reaction kettle, stir uniformly, introduce nitrogen into the reaction kettle, heat and control the temperature of the material in the reaction kettle at 95℃, add triethoxysilane into the reaction kettle under stirring, after the end of the drop, stir for 8h, remove toluene by distillation under reduced pressure, to obtain an epoxy silicone oil modified silane coupling agent; wherein the molar ratio of double bond in end double bond end epoxy group silicone oil and triethoxysilane is 1:1.05, the mass of p-hydroxyanisole is 0.5% of the mass of end double bond end epoxy group silicone oil, the mass of chloroplatinic acid is 0.01% of the mass of end double bond end epoxy group silicone oil, and the mass of toluene is 50% of the mass of end double bond end epoxy group silicone oil; the structure of the epoxy silicone oil modified silane coupling agent is as follows: .

[0056] (3) Put the epoxy silicone oil modified silane coupling agent, ethanol and deionized water with a mass ratio of 10:40:8 into a reaction kettle, then add hydrochloric acid into the reaction kettle, adjust the pH of the material in the reaction kettle to 5, then add the ethanol dispersion liquid of nano-aluminum oxide with a mass fraction of 20% into the reaction kettle, heat the material in the reaction kettle to 80℃, and stir for 10h, then filter, wash the filter cake with ethanol, and obtain an epoxy silicone oil modified nano-aluminum oxide; wherein the mass ratio of the epoxy silicone oil modified silane coupling agent and the nano-aluminum oxide is 10:3, and the average particle size of the nano-aluminum oxide is 70nm.

[0057] (4) Put 3-mercaptopropyl triethoxysilane, ethanol and deionized water with a mass ratio of 7:40:8 into a reaction kettle, then add hydrochloric acid into the reaction kettle, adjust the pH of the material in the reaction kettle to 5, then add the ethanol dispersion liquid of fibrous serpentine fiber with a mass fraction of 0.7% into the reaction kettle, heat the material in the reaction kettle to 80℃, and stir for 8h, then filter, wash the filter cake with ethanol, and obtain a mercapto modified inorganic fiber; wherein the mass ratio of 3-mercaptopropyl triethoxysilane and fibrous serpentine fiber is 3:1, the average length of fibrous serpentine fiber is 10μm, and the average diameter is 50nm.

[0058] (5) Put trimethylol aminomethane, sodium chloride, tannic acid and water with a mass ratio of 0.5:2.5:0.5:180 into a stirring kettle, stir until the solids are fully dissolved, to obtain a mixed liquid, adjust the pH of the mixed liquid to 9 by using 0.1mol / L hydrochloric acid, to obtain a modified liquid; immerse the polypropylene fiber in the modified liquid, place it on a shaking bed oscillator for oscillation, the rotation speed is 250r / min, after oscillation for 30h, take out the polypropylene fiber, wash it with deionized water, and dry to obtain a phenolic compound modified polypropylene fiber; the average diameter of the polypropylene fiber is 50μm, and the average length is 20mm.

[0059] (6) adding 3-mercaptopropyl triethoxysilane, ethanol and deionized water with a mass ratio of 8:40:8 into a reaction kettle, then adding hydrochloric acid into the reaction kettle, adjusting the pH of the materials in the reaction kettle to 5, then adding the ethanol dispersion liquid of the phenolic compound modified polypropylene fiber with a mass fraction of 8% into the reaction kettle, heating the materials in the reaction kettle to 80℃, and stirring to reflux for 8h, filtering, washing the filter cake with ethanol, and obtaining the mercapto-modified polypropylene fiber; wherein the mass ratio of 3-mercaptopropyl triethoxysilane and the phenolic compound modified polypropylene fiber is 5:1.

[0060] (7) ultrasonic dispersing epoxy silicone oil modified nano alumina, mercapto-modified inorganic fiber, mercapto-modified polypropylene fiber and ethanol to obtain a mixed liquid, then adding tetrabutylammonium fluoride into the mixed liquid, stirring at room temperature for 35min, then heating to 60℃, stirring to react for 8h, removing ethanol by reduced pressure distillation, and drying to obtain the alumina fiber composite; wherein the mass ratio of the mercapto-modified inorganic fiber and the mercapto-modified polypropylene fiber is 5:3, the ratio of the sum of the molar amounts of the mercapto groups in the mercapto-modified inorganic fiber and the mercapto-modified polypropylene fiber to the molar amount of the epoxy groups in the epoxy silicone oil modified nano alumina is 1.4:1, the mass of tetrabutylammonium fluoride is 0.08% of the mass of the epoxy silicone oil modified nano alumina, and the mass ratio of the epoxy silicone oil modified nano alumina and ethanol is 1:5.

[0061] (8) stirring calcium sulfate, calcium oxide, iron oxide and the alumina fiber composite uniformly to obtain the anti-cracking waterproof agent suitable for the lining of long-distance water conveying tunnels in cold regions; wherein the mass ratio of calcium sulfate, calcium oxide, iron oxide and the alumina fiber composite is 40:8:4:15.

[0062] Comparative Example 1

[0063] The preparation method of the anti-cracking waterproof agent suitable for the lining of long-distance water conveying tunnels in cold regions of the present comparative example is only different from the preparation method of the anti-cracking waterproof agent suitable for the lining of long-distance water conveying tunnels in cold regions of Example 1 in that the tannic acid in step (5) of the preparation method of the anti-cracking waterproof agent suitable for the lining of long-distance water conveying tunnels in cold regions of the present comparative example is replaced by dopamine.

[0064] Comparative Example 2

[0065] The preparation method of the anti-cracking waterproof agent suitable for the lining of long-distance water conveying tunnels in cold regions of the present comparative example is only different from the preparation method of the anti-cracking waterproof agent suitable for the lining of long-distance water conveying tunnels in cold regions of Example 1 in that the tannic acid in step (5) of the preparation method of the anti-cracking waterproof agent suitable for the lining of long-distance water conveying tunnels in cold regions of the present comparative example is replaced by resorcinol.

[0066] Comparative Example 3

[0067] The preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of the present comparative example differs from the preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of Example 1 only in that the fibrous serpentine fibers are replaced by sepiolite mineral fibers in step (4) of the preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of the present comparative example.

[0068] Comparative Example 4

[0069] The preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of the present comparative example differs from the preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of Example 1 only in that the fibrous serpentine fibers are replaced by basalt fibers in step (4) of the preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of the present comparative example.

[0070] Comparative Example 5

[0071] The preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of the present comparative example differs from the preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of Example 1 only in that the average particle size of the nano-aluminum oxide is 20 nm in step (3) of the preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of the present comparative example.

[0072] Comparative Example 6

[0073] The preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of the present comparative example differs from the preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of Example 1 only in that the average particle size of the nano-aluminum oxide is 100 nm in step (3) of the preparation method of the anti-cracking waterproofing agent for lining of long-distance water conveying tunnels in cold regions of the present comparative example.

[0074] Effect Example

[0075] In order to evaluate the application effect of the anti-cracking waterproofing agent prepared in the application in the lining of water conveying tunnels in cold regions, the anti-cracking waterproofing agents prepared in each example and the comparative example are applied to the preparation of concrete. The cement used in the preparation of the concrete is ordinary Portland cement (the mark is P.O42.5), and the concrete is prepared by stirring and mixing cement, sand, gravel and water in a mass ratio of 300:900:950:170. The fineness modulus of the sand is 2.8, the average particle size of the gravel is 10 mm, and the dosage of the anti-cracking waterproofing agent in the concrete is 7%. The concrete without the addition of the anti-cracking waterproofing agent and the concrete with the addition of the anti-cracking waterproofing agent are prepared into concrete test blocks, and the setting time, compressive strength, flexural strength, limited expansion rate, bleeding rate ratio, penetration height ratio, 48h water absorption ratio, crack reduction coefficient, maximum water permeation pressure and frost resistance grade of the concrete are tested. Among them, the setting time is tested according to the method in the standard GB1346-2011, and the average value of the test results is taken as the final result, with each test piece being tested repeatedly for 3 times; the compressive strength and the flexural strength are tested according to the method in the standard GB-T50081-2002, and the average value of the test results is taken as the final result, with each test piece being tested repeatedly for 3 times; the limited expansion rate is tested according to the method in the standard GB / T 23439-2017, and the average value of the test results is taken as the final result, with each test piece being tested repeatedly for 3 times; the bleeding rate ratio, the penetration height ratio and the 48h water absorption ratio are tested according to the method in the standard JC-474-1999, and the average value of the test results is taken as the final result, with each test piece being tested repeatedly for 3 times; the crack reduction coefficient is tested according to the method in the standard CECS 38-2004, and the average value of the test results is taken as the final result, with each test piece being tested repeatedly for 3 times; the maximum water permeation pressure and the frost resistance grade are tested according to the method in the standard GB / T 50082-2009, and the average value of the test results is taken as the final result, with each test piece being tested repeatedly for 3 times. Among them, the frost resistance grade is represented by the maximum number of freeze-thaw cycles that the test block with an age of 28d can withstand after being saturated with water, and the compressive strength decreases by not more than 25% and the mass loss is not more than 5%.

[0076] The test results of the setting time, compressive strength, flexural strength and limited expansion rate of the concrete corresponding to the anti-cracking waterproofing agents prepared in each example and the comparative example are shown in Table 1. The test results of the bleeding rate ratio, penetration height ratio, 48h water absorption ratio, crack reduction coefficient, maximum water permeation pressure and frost resistance grade of the concrete corresponding to the anti-cracking waterproofing agents prepared in each example and the comparative example are shown in Table 2.

[0077] Table 1 The setting time, compressive strength, flexural strength and limited expansion rate of the concrete corresponding to the anti-cracking waterproofing agents prepared in each example and the comparative example

[0078]

[0079] Table 2: Bleeding ratio, penetration height ratio, 48h water absorption ratio, crack reduction coefficient, maximum water permeation pressure and frost resistance grade of the concrete corresponding to the anti-cracking waterproofing agent prepared in each example and comparative example

[0080]

[0081] As can be seen from the test results in Table 1 and Table 2, the anti-cracking waterproofing agent prepared in the present application can effectively improve the tensile strength, flexural strength, waterproof performance, crack resistance, impermeability and frost resistance of the concrete, which shows that the hydrophobic silicone segment is grafted to the surface of the nano-alumina, and the mercapto-modified serpentine fiber and the mercapto-modified polypropylene fiber are reacted through the mercapto group and the epoxy group grafted to the surface of the nano-alumina, so that the nano-alumina, the serpentine fiber and the polypropylene fiber are bonded together through the hydrophobic long chain, thereby improving the bonding force among them. When the anti-cracking waterproofing agent prepared in the present application is used in the concrete, the silicon oil molecular chain connecting the nano-alumina, the serpentine fiber and the polypropylene fiber contains a large number of hydrophilic hydroxyl groups, and the lipophilic silicone segment and the hydrophilic hydroxyl group cooperate with each other to form a good surface active system, thereby improving the dispersibility of the alumina fiber composite in the water-based concrete slurry. The serpentine fiber and the polypropylene fiber form a branched network structure with the nano-alumina as the center core point, thereby improving the dispersion uniformity of the serpentine fiber and the polypropylene fiber, avoiding the disorder, intersection and entanglement of the linear fibers, improving the contact area with the concrete, and further improving the support to the main structure of the concrete. When subjected to external force, the cracking of the concrete is reduced. At the same time, since the nano-alumina, the serpentine fiber and the polypropylene fiber are bonded together through chemical bonds, the three can form a stable anchoring structure, thereby improving the tensile strength, flexural strength, waterproof performance and maximum water permeation pressure of the concrete; the hydrophobic long chain among the three can further improve the waterproof performance and maximum water permeation pressure of the concrete. In addition, the tannin acid polymer deposited on the surface of the polypropylene fiber can improve the wettability and dispersibility of the lipophilic polypropylene fiber in the concrete slurry, and can improve the surface roughness of the polypropylene fiber, thereby improving the embedding strength and affinity of the polypropylene fiber with the concrete, and further improving the strength, waterproofness and impermeability of the concrete. Finally, the long-chain silicon oil segment between the nano-alumina, the serpentine fiber and the polypropylene fiber and the tannin acid polymer on the surface of the polypropylene fiber can endow the alumina fiber composite with certain elasticity, thereby improving the crack resistance and frost resistance grade of the concrete.

[0082] From Example 1 and Comparative Examples 1-2, it can be seen that after the tannin acid polymer deposited on the surface of the polypropylene fiber is replaced by a polydopamine or a resorcinol polymer, the comprehensive performance of the concrete is reduced, which may be due to the fact that the number of phenolic hydroxyl groups in the polymer formed by the dopamine or resorcinol is small, and the affinity with the concrete slurry is poor, so that the polypropylene fiber cannot be well dispersed in the concrete, and thus cannot play the corresponding role.

[0083] From Example 1 and Comparative Examples 3-4, it can be seen that after the chrysotile fiber is replaced by sepiolite mineral fiber or basalt fiber, the comprehensive performance of the concrete is also reduced, which may be due to the fact that the adsorption capacity of the sepiolite mineral fiber and the basalt fiber is too strong, and when the sepiolite mineral fiber and the basalt fiber are used together with the polypropylene fiber coated with the tannin acid polymer, the sepiolite mineral fiber and the basalt fiber will form a strong adsorption effect on the phenolic hydroxyl groups and other groups on the surface of the tannin acid polymer, so that the polypropylene fiber cannot be well dispersed and cannot form a divergent structure, resulting in a decrease in the overall performance.

[0084] From Example 1 and Comparative Examples 5-6, it can be seen that when the particle size of the nano-alumina is increased or decreased, the comprehensive performance of the concrete is significantly reduced, which shows that the particle size of the nano-alumina is crucial to the performance of the alumina fiber composite. When the particle size of the nano-alumina is too large, a good balanced system cannot be formed between the chrysotile fiber, the polypropylene fiber and the nano-alumina, so that the chrysotile fiber and the polypropylene fiber cannot be well dispersed in the concrete and form a network divergent structure with the nano-alumina, and thus the role of the alumina fiber composite is weakened; when the particle size of the nano-alumina is too small, it cannot form a good central core point, so that the chrysotile fiber and the polypropylene fiber are easily moved and entangled, and cannot form a good network divergent structure, which also leads to a decrease in the performance of the concrete.

Claims

1. A method for preparing an anti-cracking waterproofing agent suitable for lining long-distance water tunnels in cold regions, characterized in that: The following steps are involved: Calcium sulfate, calcium oxide, iron oxide, and an alumina fiber composite are mixed to obtain an anti-cracking waterproofing agent suitable for lining long-distance water transmission tunnels in cold regions; the mass ratio of the calcium sulfate, calcium oxide, iron oxide, and alumina fiber composite is 30-40:5-8:3-4:10-15; the preparation method of the alumina fiber composite is as follows: (1) Double bond-terminated epoxy-terminated silicone oil and triethoxysilane are reacted to obtain epoxy silicone oil-modified silane coupling agent; the structure of double bond-terminated epoxy-terminated silicone oil is as follows: ； The structure of epoxy silicone oil modified silane coupling agent is as follows: ； (2) reacting an epoxy silicone oil-modified silane coupling agent with nano-alumina to obtain epoxy silicone oil-modified nano-alumina; the average particle size of the nano-alumina is 40 to 70 nm; (3) reacting 3-mercaptopropyltriethoxysilane with chrysotile fiber to obtain mercapto-modified inorganic fiber; (4) reacting tannic acid with polypropylene fiber to obtain phenolic compound modified polypropylene fiber; then reacting the phenolic compound modified polypropylene fiber with 3-mercaptopropyltriethoxysilane to obtain mercapto modified polypropylene fiber; (5) Epoxy silicone oil modified nano-alumina, mercapto modified inorganic fiber and mercapto modified polypropylene fiber are reacted to obtain an alumina fiber composite; the mass ratio of mercapto modified inorganic fiber and mercapto modified polypropylene fiber is 3~5:2~3, and the ratio of the sum of the molar amounts of mercapto groups in the mercapto modified inorganic fiber and mercapto modified polypropylene fiber to the molar amount of epoxy groups in the epoxy silicone oil modified nano-alumina is 1.2~1.4:

1.

2. The method for preparing the anti-cracking waterproofing agent suitable for lining of long-distance water tunnels in cold regions according to claim 1, characterized in that: The double-bond-terminated epoxy-terminated silicone oil is prepared by mixing epoxy-terminated silicone oil and acrylic acid under the catalysis of tetrabutylammonium bromide at 90-100° C. for 5-7 hours; the molar ratio of epoxy group to acrylic acid in the epoxy-terminated silicone oil is 2:

1.

3. The method for preparing the anti-cracking waterproofing agent suitable for lining of long-distance water tunnels in cold regions according to claim 2, characterized in that: The number average molecular weight of the epoxy-terminated silicone oil is 1500-3000.

4. The method for preparing the anti-cracking waterproofing agent suitable for lining of long-distance water tunnels in cold regions according to claim 1, characterized in that: When the double-bond-terminated epoxy-terminated silicone oil and triethoxysilane react, chloroplatinic acid is used as a catalyst, p-hydroxyanisole is used as a polymerization inhibitor, the reaction temperature is 85-95° C., and the reaction time is 6-8 hours. The molar ratio of the double bond and triethoxysilane in the double-bond-terminated epoxy-terminated silicone oil is 1:1.02-1.05, the mass of p-hydroxyanisole is 0.2-0.5% of the mass of the double-bond-terminated epoxy-terminated silicone oil, and the mass of chloroplatinic acid is 0.007-0.01% of the mass of the double-bond-terminated epoxy-terminated silicone oil.

5. The method for preparing the anti-cracking waterproof agent suitable for lining of long-distance water tunnels in cold regions according to claim 1, characterized in that: The method for reacting an epoxy silicone oil-modified silane coupling agent and nano-alumina is as follows: uniformly mix the epoxy silicone oil-modified silane coupling agent, ethanol, and water in a mass ratio of 10:30-40:5-8, then adjust the pH to 4-5 with hydrochloric acid, add an ethanol dispersion of nano-alumina with a mass fraction of 15-20%, heat to 70-80°C, and mix for 7-10 hours to obtain epoxy silicone oil-modified nano-alumina; the mass ratio of the epoxy silicone oil-modified silane coupling agent to the nano-alumina is 10:2-3.

6. The method for preparing the anti-cracking waterproofing agent suitable for lining of long-distance water tunnels in cold regions according to claim 1, characterized in that: The method for reacting 3-mercaptopropyltriethoxysilane with chrysotile fibers is as follows: 3-mercaptopropyltriethoxysilane, ethanol, and water are mixed at a mass ratio of 7:30-40:5-8, and then the pH is adjusted to 4-5 with hydrochloric acid. Then, an ethanol dispersion of chrysotile fibers with a mass fraction of 0.4-0.7% is added, and the mixture is heated to 70-80°C and mixed for reaction for 5-8 hours to obtain mercapto-modified inorganic fibers. The mass ratio of 3-mercaptopropyltriethoxysilane to chrysotile fibers is 2-3:1, and the average length of the chrysotile fibers is 7-10 μm and the average diameter is 30-50 nm.

7. The method for preparing the anti-cracking waterproof agent suitable for lining of long-distance water tunnels in cold regions according to claim 1, characterized in that: The method for reacting tannic acid with polypropylene fiber is as follows: tris(hydroxymethyl)aminomethane, sodium chloride, tannic acid, and water are mixed in a mass ratio of 0.5:2.5:0.5:150-180 to obtain a mixed solution, and then the pH of the mixed solution is adjusted to 8-9 to obtain a modified solution; The polypropylene fiber is immersed in the modification liquid and subjected to an oscillation reaction at a rotation speed of 200-250 r / min for 24-30 hours to obtain the phenolic compound modified polypropylene fiber.

8. The method for preparing the anti-cracking waterproofing agent suitable for lining of long-distance water tunnels in cold regions according to claim 7, characterized in that: The polypropylene fibers have an average diameter of 30-50 μm and an average length of 15-20 mm.

9. The method for preparing the anti-cracking waterproof agent suitable for lining of long-distance water tunnels in cold regions according to claim 1, characterized in that: The method for reacting phenolic compound-modified polypropylene fiber and 3-mercaptopropyltriethoxysilane is as follows: 3-mercaptopropyltriethoxysilane, ethanol and water in a mass ratio of 8:30-40:5-8 are mixed uniformly, and then the pH is adjusted to 4-5 with hydrochloric acid, and then an ethanol dispersion of phenolic compound-modified polypropylene fiber with a mass fraction of 5-8% is added, and the mixture is heated to 70-80° C. and mixed and reacted for 5-8 hours to obtain mercapto-modified polypropylene fiber; the mass ratio of 3-mercaptopropyltriethoxysilane to phenolic compound-modified polypropylene fiber is 3-5:

1.

10. The method for preparing the anti-cracking waterproof agent suitable for lining of long-distance water tunnels in cold regions according to claim 1, characterized in that: When epoxy silicone oil modified nano-alumina, mercapto modified inorganic fiber and mercapto modified polypropylene fiber are reacted, tetrabutylammonium fluoride is used as a catalyst, the reaction temperature is 50-60°C, the reaction time is 6-8 hours, and the mass of tetrabutylammonium fluoride is 0.05-0.08% of the mass of epoxy silicone oil modified nano-alumina.

Images