Freeze-thaw-resistant self-repairing epoxy resin grouting material for repairing tunnel lining in severe cold area and preparation method

Abstract

The invention discloses a freeze-thaw-resistant self-repairing epoxy resin grouting material for repairing tunnel linings in severe cold areas and a preparation method of the freeze-thaw-resistant self-repairing epoxy resin grouting material. The grouting material is formed by mixing modified epoxy resin, a diluent, a modified curing agent, self-repairing microcapsules and an accelerant, wherein the modified epoxy resin is a mixture of bisphenol A epoxy resin, hydrogenated epoxy resin and vanillin epoxy resin; the diluent is an active diluent formed by mixing 1, 2-cyclohexyldialkyl glycidyl ether, furfural and acetone; the modified curing agent is a binary mixture of polyethyleneimine and cardanol aldehyde amine; the self-repairing microcapsule is a silicon dioxide coated polyurethane microcapsule. The prepared epoxy grouting material is low in viscosity, high in low-temperature reaction speed, excellent in low-temperature curing performance and good in freeze-thaw environment durability, and can be widely applied to seepage-proofing reinforcement of tunnel linings and related buildings in severe cold areas.

Description

Technical Field

[0001] The present invention relates to a polymer grouting material and a preparation method thereof, and particularly to an anti-freeze-thaw self-healing epoxy resin grouting material for tunnel lining repair in cold regions and a preparation method thereof. Background Art

[0002] Cracks in tunnel lining concrete are the most common diseases in traffic tunnels. Especially in high-altitude and cold regions, due to large day-night temperature differences and long freeze-thaw cycles, water seepage frequently occurs during the rainy season and structural cracking is serious in winter, resulting in a significant reduction in the service life of tunnel projects and huge potential safety hazards. For cracks in tunnel linings in cold regions, if not effectively controlled, it will further accelerate the damage area of the lining structure, reduce the mechanical properties of the lining structure and degrade its durability, threatening tunnel operation.

[0003] Polymer grouting is one of the most effective methods for dealing with leakage in traffic tunnel linings. As a polymer, epoxy resin is widely used in the repair projects of railway and highway tunnel linings due to its excellent physical and mechanical properties. However, the traditional epoxy resin material has high requirements for environmental temperature during curing and forming (30 - 180°C), and is often only suitable for grouting reinforcement at normal temperature. In cold regions where the temperature is below 0°C, due to construction condition limitations, the curing speed of conventional epoxy resin grouting materials is slow, and they may not even be completely cured for a long time, unable to meet the engineering application requirements in cold environments. In addition, in cold regions, the freeze-thaw cycle process has a long period, and the material expands and contracts frequently due to heat, and the traditional epoxy resin is brittle and has insufficient corrosion resistance, often causing secondary peeling and cracking from the concrete surface, and it is difficult to meet the engineering application requirements. Summary of the Invention

[0004] Aiming at the problems of difficult curing, slow curing and poor weather resistance of traditional epoxy resin grouting materials in cold regions, the present invention provides an anti-freeze-thaw self-healing epoxy resin grouting material for tunnel lining repair in cold regions and a preparation method thereof. This epoxy resin grouting material has properties such as fast curing at low temperature, anti-freeze-thaw, anti-ultraviolet and weather resistance.

[0005] The object of the present invention is achieved through the following technical solutions:

[0006] An anti-freeze-thaw self-healing epoxy resin grouting material for tunnel lining repair in cold regions is prepared by mixing the following raw materials in parts by weight: 30 - 60 parts of modified epoxy resin, 10 - 20 parts of diluent, 9 - 18 parts of modified curing agent, 10 - 20 parts of self-healing microcapsules, 1 - 2 parts of accelerator, wherein:

[0007] The modified epoxy resin is a mixture of bisphenol A epoxy resin, hydrogenated epoxy resin and vanillin epoxy resin, and the mass ratio of bisphenol A epoxy resin, hydrogenated epoxy resin and vanillin epoxy resin is 3 - 6:2 - 5:1 - 2;

[0008] The diluent is an active diluent composed of 1,2-cyclohexanedimethanol diglycidyl ether, furfural, and acetone, and the mass ratio of 1,2-cyclohexanedimethanol diglycidyl ether, furfural, and acetone is 1-2:1-2:1;

[0009] The modified curing agent is a binary mixture of polyethyleneimine and cardanol phenolic amine, and the mass ratio of polyethyleneimine and cardanol phenolic amine is 3-1:1;

[0010] The self-healing microcapsules are silicon dioxide-coated polyurethane microcapsules;

[0011] The accelerator is triethylbenzylammonium chloride or 2,4,6-tris(dimethylaminomethyl)phenol.

[0012] A preparation method of the above-mentioned freeze-thaw resistant self-healing epoxy grouting material for tunnel lining repair in cold regions includes the following steps:

[0013] Step (1) Preparation of vanillin epoxy resin: Vanillin and polyglycidyl ether react at a molar ratio of 1:1 at 80-150 °C for 5-10 h, and are naturally cooled to obtain vanillin-based epoxy resin;

[0014] Step (2) Preparation of self-healing microcapsules: Tetraethoxysilane is adjusted to pH 2 with oxalic acid, then stirred and mixed with polyurethane prepolymer to form an emulsion, and further adjusted to pH 10 with 0.1 mol / L ammonia water solution to obtain a microcapsule suspension, which is allowed to stand and age, centrifuged, and dried at 80-100 °C to obtain silicon dioxide-coated polyurethane microcapsules;

[0015] Step (3) Heat bisphenol A epoxy resin, hydrogenated epoxy resin, and vanillin epoxy resin to 80-100 °C, and keep stirring and reacting for 1-2 h to obtain modified epoxy resin;

[0016] Step (4) Weigh 1,2-cyclohexanedimethanol diglycidyl ether, furfural, and acetone, and stir at room temperature for 0.5-2 hours to prepare an active diluent;

[0017] Step (5) Mix the self-healing microcapsules, active diluent, and modified epoxy resin evenly according to the mass ratio of 1-2:1-2:3-6 to prepare liquid A;

[0018] Step (6) Mix polyethyleneimine and cardanol phenolic amine evenly at room temperature according to the mass ratio of 3-1:1 to obtain a modified curing agent;

[0019] Step (7) Add an accelerator to the modified curing agent and mix evenly at room temperature to prepare liquid B;

[0020] Step (8) Mix liquid A and liquid B in a mass ratio of 5-10:1-2, and stir evenly to obtain an anti-freeze-thaw self-healing epoxy resin grouting material for repairing tunnel linings in cold regions.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The anti-freeze-thaw self-healing epoxy resin grouting material for repairing tunnel linings in cold regions of the present invention is formed by compounding modified epoxy resin with phenolic amine curing agent, diluent, and self-healing microcapsules. The present invention modifies epoxy resin with biomass vanillin, which not only greatly improves the low-temperature curing speed, but also effectively improves the toughness of epoxy resin and reduces the initial viscosity of epoxy resin.

[0023] 2. The self-healing microcapsules improve the flexibility of epoxy resin through nano-toughening. At the same time, when cracks appear in epoxy resin during damage, polyurethane prepolymer is released, and after rapid reaction with water molecules, crack self-healing occurs, significantly improving the anti-freeze-thaw and anti-aging properties of epoxy resin.

[0024] 3. The epoxy grouting material prepared by the present invention has low viscosity, fast low-temperature reaction speed, excellent low-temperature curing performance, good durability in freeze-thaw environment, and can be widely used in the anti-seepage reinforcement of tunnel linings and related buildings in cold regions. Specific Embodiments

[0025] The technical solutions of the present invention will be further described below in conjunction with embodiments, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be covered by the protection scope of the present invention.

[0026] Example 1:

[0027] This example provides a preparation method of an anti-freeze-thaw self-healing epoxy resin grouting material for repairing tunnel linings in cold regions, and the method includes the following steps:

[0028] (1) Preparation of vanillin epoxy resin: Weigh 100 parts of vanillin and 120 parts of polyglycidyl ether, react at 80 °C for 5 h, and cool naturally to obtain vanillin-based epoxy resin.

[0029] (2) Preparation of self-healing microcapsules: Adjust the pH of 50 parts of tetraethoxysilane to 2 with 0.1 mol / L oxalic acid, then stir and mix it with 100 parts of polyurethane prepolymer to form an emulsion. Further adjust the pH of the emulsion to 10 with 0.1 mol / L ammonia water solution to obtain a microcapsule suspension, let it stand for aging, centrifuge, and dry at 80 °C to obtain silica-coated polyurethane microcapsules.

[0030] (3) Weigh 300 parts of bisphenol A epoxy resin E51, 100 parts of hydrogenated epoxy resin, and 100 parts of vanillin epoxy resin, heat them to 80 °C, stir and react for 2 h, and cool to room temperature to obtain the modified epoxy resin.

[0031] (4) Weigh 100 parts of 1,2-cyclohexanedimethanol glycidyl ether, 100 parts of furfural, and 100 parts of acetone, stir at room temperature for 1 hour to prepare the active diluent.

[0032] (5) Mix 20 parts of self-healing microcapsules, 20 parts of active diluent, and 60 parts of modified epoxy resin evenly to obtain Liquid A.

[0033] (6) Mix 90 parts of polyethyleneimine and 90 parts of cardanol phenolic amine evenly at room temperature to obtain the modified curing agent; add 20 parts of the accelerator 2,4,6-tris(dimethylaminomethyl)phenol to it and mix evenly at room temperature to obtain Liquid B.

[0034] (7) Weigh 50 parts of Liquid A and 10 parts of Liquid B, mix them evenly to prepare the anti-freeze-thaw self-healing epoxy grouting material for repairing tunnel linings in cold regions, and the performance test results are shown in Table 1.

[0035] Example 2:

[0036] The difference between this example and Example 1 is that in step (5), 20 parts of self-healing microcapsules, 20 parts of active diluent, and 50 parts of modified epoxy resin are weighed and mixed evenly to prepare the anti-freeze-thaw self-healing epoxy grouting material for repairing tunnel linings in cold regions, and the performance test results are shown in Table 1.

[0037] Example 3:

[0038] The difference between this example and Example 1 is that in step (5), 20 parts of self-healing microcapsules, 20 parts of active diluent, and 40 parts of modified epoxy resin are weighed and mixed evenly to prepare the anti-freeze-thaw self-healing epoxy grouting material for repairing tunnel linings in cold regions, and the performance test results are shown in Table 1.

[0039] Example 4:

[0040] The difference between this example and Example 1 is that in step (7), 50 parts of Liquid A and 15 parts of Liquid B are weighed and mixed evenly to prepare the anti-freeze-thaw self-healing epoxy grouting material for repairing tunnel linings in cold regions, and the performance test results are shown in Table 1.

[0041] Example 5:

[0042] The difference between this example and Example 1 is that in step (7), 50 parts of Liquid A and 20 parts of Liquid B are weighed and mixed evenly to prepare the anti-freeze-thaw self-healing epoxy grouting material for repairing tunnel linings in cold regions, and the performance test results are shown in Table 1.

[0043] Comparative example:

[0044] The difference between this example and Example 1 is that in step (5), 0 parts of self-healing microcapsules, 10 parts of reactive diluent and 50 parts of modified epoxy resin are weighed and mixed evenly to prepare an anti-freezing and thawing self-healing epoxy resin grouting material for repairing tunnel linings in cold regions. The performance test results are shown in Table 1.

[0045] Table 1 Performance test results of examples and comparative examples

[0046]

[0047]

[0048] It can be seen from Table 1 that Example 4 has the most excellent comprehensive performance, with a temperature of -10°C, an initial viscosity of 180 mPa·s, an initial setting time of 120 min, a dry bond strength of 3.2 MPa after 30 days of freeze-thaw cycles at -10°C to 40°C, and a damage repair rate of 86%, meeting the long-term reinforcement requirements for tunnel linings in cold regions.

Claims

1. A freeze-thaw resistant self-repairing epoxy resin grouting material for tunnel lining repair in severe cold regions, characterized in that The grouting material is mixed by the following raw materials in parts by weight: 30-60 parts of modified epoxy resin, 10-20 parts of diluent, 9-18 parts of modified curing agent, 10-20 parts of self-repairing microcapsules, and 1-2 parts of accelerator, wherein: the modified epoxy resin is a mixture of bisphenol A epoxy resin, hydrogenated epoxy resin, and vanillin epoxy resin, and the mass ratio of bisphenol A epoxy resin, hydrogenated epoxy resin, and vanillin epoxy resin is 3-6:2-5:1-2; the diluent is an active diluent mixed with 1,2-cyclohexane diglycidyl ether, furfural, and acetone, and the mass ratio of 1,2-cyclohexane diglycidyl ether, furfural, and acetone is 1-2:1-2:1; the modified curing agent is a binary mixture of polyethyleneimine and cashew phenol aldehyde amine, and the mass ratio of polyethyleneimine to cashew phenol aldehyde amine is 3-1:1; the self-repairing microcapsules are silica-coated polyurethane microcapsules.

2. The anti-freeze-thaw self-repairing epoxy resin grouting material for tunnel lining repair in severe cold regions according to claim 1 is characterized in that The accelerator is triethylbenzylammonium chloride or 2,4,6-tris(dimethylaminomethyl)phenol.

3. A method for preparing the freeze-thaw resistant self-repairing epoxy resin grouting material for repairing tunnel lining in severe cold regions according to any one of claims 1 to 2, characterized in that The method comprises the following steps: Step (1) Preparation of vanillin epoxy resin: vanillin and polyglycidyl ether are reacted at a molar ratio of 1:1 at 80-150° C. for 5-10 hours, and naturally cooled to obtain a vanillin-based epoxy resin; Step (2) Preparation of self-repairing microcapsules: tetraethoxysilane is adjusted to pH 2 with oxalic acid, and then stirred and mixed with a polyurethane prepolymer to form an emulsion, and the pH of the emulsion is further adjusted to 10 with a 0.1 mol / L ammonia solution to obtain a microcapsule suspension, which is allowed to stand for aging, centrifuged, and dried at 80-100° C. to obtain silica-coated polyurethane microcapsules; Step (3) heating the bisphenol A epoxy resin, hydrogenated epoxy resin and vanillin epoxy resin to 80-100° C., stirring and reacting for 1-2 hours to obtain a modified epoxy resin; Step (4) weighing 1,2-cyclohexane diglycidyl ether, furfural, and acetone, stirring at room temperature for 0.5 to 2 hours to prepare a reactive diluent; Step (5) mixing the self-repairing microcapsules, the active diluent and the modified epoxy resin to obtain liquid A; Step (6) uniformly mixing polyethyleneimine and cardanol aldehyde amine at room temperature to obtain a modified curing agent; Step (7) adding an accelerator to the modified curing agent and mixing them uniformly at room temperature to obtain liquid B; Step (8) Mix the liquid A and the liquid B in step A, stir them evenly to obtain the freeze-thaw resistant self-repairing epoxy resin grouting material for repairing tunnel lining in severe cold regions.

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