High-performance two-component epoxy pouring adhesive for concrete underwater cracks and preparation method of high-performance two-component epoxy pouring adhesive

Abstract

The invention relates to the technical field of building materials for concrete, in particular to a high-performance two-component epoxy pouring adhesive for underwater cracks of concrete and a preparation method of the high-performance two-component epoxy pouring adhesive for the underwater cracks of the concrete. The epoxy pouring adhesive which is low in viscosity, high in underwater bonding strength, free of whitening underwater, excellent in mechanical property, high in chemical corrosion resistance and super-hydrophobic is prepared by taking epoxy resin as a main component, taking bisphenol A epoxy resin, bisphenol F epoxy resin and an epoxy coupling agent as well as adopting a specially-made modified amine curing agent and an amino coupling agent as curing agent components. The method can be used for repair engineering of various concrete underwater crack environments and concrete wet crack environments.

Description

Technical Field

[0001] The invention relates to the technical field of concrete building materials, in particular to a high-performance two-component epoxy grouting adhesive for underwater cracks in concrete and a preparation method thereof. Background Art

[0002] Concrete structures (such as bridges, buildings, water conservancy and hydropower projects, and tunnels) often develop cracks due to long-term exposure to environmental erosion, water pressure, and other factors, seriously impacting the project's safety, durability, and aesthetics. While conventional epoxy crack caulking adhesives offer excellent stability, low shrinkage, room-temperature curing, and strong adhesion, they suffer from significant drawbacks in humid environments or those exposed to prolonged water immersion. These include insufficient water resistance leading to interfacial delamination, difficulty in underwater curing resulting in whitening, and insufficient toughness that prevents them from adapting to the dynamic deformation of concrete cracks. Engineering investigations have shown that concrete crack repairs using conventional epoxy caulking adhesives often require repair within less than a year.

[0003] Chinese invention patent CN109957367A discloses a method for preparing a modified epoxy resin concrete crack grouting adhesive, which uses epoxy-terminated nitrile rubber to impart a certain toughness and exhibit good mechanical and adhesive properties in dry concrete crack repair. However, it lacks waterproofing and is not suitable for repairing wet concrete cracks and underwater cracks. Chinese invention patent CN104817992A discloses a novel two-component epoxy resin adhesive for crack grouting and a method for preparing the same. The grouting adhesive can be cured at low temperatures, has low viscosity, and high strength, but is still not suitable for repairing wet concrete cracks and underwater cracks. Chinese invention patent CN114561177A discloses an epoxy grouting adhesive for repairing wet concrete cracks and a method for preparing the same. By adding hydrophilic ether bonds and -SO3Na groups to the epoxy resin, the resin's hydrophilicity is improved. The grouting adhesive can meet the requirements for repairing wet concrete cracks, but the use of a ketimine curing agent in the curing agent system results in a whitening phenomenon, resulting in reduced adhesion and making it impossible to repair underwater concrete cracks.

[0004] In order to address the common moisture cracks or underwater cracks in concrete, it is necessary to break through the technical limitations of conventional epoxy grouting adhesives and develop epoxy grouting adhesives with good toughness, good bonding properties, excellent mechanical properties, and the ability to adapt to moisture cracks and underwater cracks in concrete. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a high-performance two-component epoxy grouting adhesive for underwater cracks in concrete. The two-component epoxy grouting adhesive consists of a resin component and a curing agent component. A modified epoxy resin is prepared by introducing a hydrophobic group using a long-chain alkane and then grafting it with an epoxy resin side chain. The modified epoxy resin is then grafted with a coupling agent. The epoxy grouting adhesive is combined with bisphenol A epoxy resin, bisphenol F epoxy resin and an epoxy coupling agent, and a specially modified amine curing agent and an amino coupling agent are used as the curing agent component to prepare an epoxy grouting adhesive with low viscosity, high underwater bonding strength, no whitening underwater, excellent mechanical properties, strong chemical corrosion resistance and super hydrophobicity. The epoxy grouting adhesive can be used for repair projects in various concrete underwater crack environments and concrete wet crack environments.

[0006] Specifically, the high-performance two-component epoxy grouting adhesive for underwater concrete cracks of the present invention is composed of a resin component and a curing agent component in a mass ratio of (2-4):1.

[0007] Preferably, the resin component is composed of the following raw materials in parts by weight: 10-20 parts of modified epoxy resin, 20-45 parts of bisphenol A epoxy resin, 30-55 parts of bisphenol F epoxy resin, 10-15 parts of reactive diluent, 1-3 parts of toughening agent, 0.1-1.5 parts of epoxy coupling agent, 0.1-1.5 parts of defoaming agent, and 1-3 parts of wetting and dispersing agent. The modified epoxy resin is prepared by introducing a long-chain alkane into a hydrophobic group, grafting it with an epoxy resin side chain, and then grafting it with a coupling agent.

[0008] Among the resin components of the present invention, the modified epoxy resin has super-hydrophobicity, can achieve complete underwater curing, and also has excellent mechanical properties. The addition of bisphenol A epoxy resin can reduce costs to a certain extent. The addition of bisphenol F epoxy resin can reduce the viscosity of the system on the one hand, and can achieve the non-crystallization of the resin system at low temperatures on the other hand. The addition of the three resins has a good synergistic effect in improving the underwater curing ability and mechanical properties. The addition of the active diluent can participate in the curing reaction and reduce the viscosity of the system. The addition of the epoxy coupling agent can participate in the curing reaction and achieve the combination of organic and inorganic, so that the grouting glue and concrete have higher bonding strength. The addition of the toughening agent can enhance the toughness of the system and prevent the glue from cracking. The addition of the wetting dispersant can better achieve the grouting glue to more easily infiltrate the concrete surface, thereby enhancing the bonding strength.

[0009] Preferably, the curing agent component is composed of the following raw materials in parts by weight: 30-40 parts of a modified amine curing agent and 1-2.5 parts of an amino coupling agent. The modified amine curing agent is prepared by mixing fluorosilicone grafted polyetheramine and hydrophobic nano-silica and then adding ethylene glycol diglycidyl ether.

[0010] In the curing agent component of the present invention, the modified amine curing agent can achieve complete underwater curing, no whitening, and good mechanical properties. The amino coupling agent can also achieve film-forming cross-linking of the resin and realize the combination of organic and inorganic, so that it has better adhesion to the concrete surface.

[0011] Preferably, the modified epoxy resin preparation process is as follows: C18 alcohol and PDMS-OH are mixed in a molar ratio of 1: (0.9-1.1), and a catalyst DMAP of (0.5-0.7)% by mass of both is added, and the reaction is carried out in vacuum to generate C18-PDMS ester. The unreacted monomer is removed by vacuum distillation to obtain a hydrophobic long-chain siloxane ester. The hydrophobic long-chain siloxane ester is reacted with epoxy resin AG-80 in a mass ratio of 1: (0.3-0.6) under alkaline conditions, and γ-glycidyloxypropyltrimethoxysilane of (10-15)% by mass of both is added, and the reaction is carried out at 80-90° C. for 2-3 hours to generate an epoxy resin-C18-PDMS network structure. 100-120 parts of the epoxy resin-C18-PDMS network structure are dissolved in toluene, 6-10 parts of KH550 are added, 0.7-0.9 parts of the catalyst boron trifluoride ethylamine are added dropwise, the reaction is stirred, and the solvent is removed by vacuum distillation to obtain the product.

[0012] Preferably, the vacuum reaction is carried out at 110-130° C. for 7-9 hours, and the stirring reaction is carried out at 70-90° C. for 5-8 hours.

[0013] Preferably, the preparation process of the modified amine curing agent is as follows: 100-110 parts of polyetheramine, 10-20 parts of KH550, and 0.1-0.9 parts of titanate are stirred under heat preservation, 30-40 parts of perfluorooctyltriethoxysilane are added, the temperature is increased for reaction, and the fluorosilicone grafted polyetheramine is obtained after reduced pressure degassing, 25-40 parts of hydrophobic nano-silica are added, high-speed shearing is performed, 25-35 parts of ethylene glycol diglycidyl ether are added, and the mixture is mixed evenly to obtain the product.

[0014] Preferably, the heat preservation stirring is stirring at 70-85° C. for 5-8 hours, the temperature rise reaction is reacting at 115-130° C. for 7-9 hours, and the high-speed shearing is high-speed shearing at 2800-3100 r / min for 40-55 minutes.

[0015] The present invention graft-modifies epoxy resin by first introducing hydrophobic groups on long-chain alkyl monomers, then grafting the hydrophobically modified alkyl monomers onto the epoxy resin, reducing the molecular polarity, and then performing ring-opening grafting with epoxy-containing silane coupling agents to form a silicon-oxygen bond network, thereby enhancing underwater anti-penetration capabilities and achieving a hydrophobic group density gradient distribution. On the other hand, the present invention graft-modifies polyetheramine by covalently grafting fluorosilane onto the main chain of the curing agent. The polyether chain segments and long fluorocarbon chains are synergistically toughened, and the polyamine groups provide a high-strength cross-linked network. Combined with hydrophobic nano-silica, hydrophobic-mechanical synergy is achieved.

[0016] Preferably, the bisphenol A epoxy resin is E-51.

[0017] Preferably, the bisphenol F epoxy resin is REF-170 bisphenol F epoxy resin.

[0018] Preferably, the reactive diluent is at least one of alkyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, benzyl glycidyl ether, ethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and propylene glycol diglycidyl ether.

[0019] Preferably, the toughening agent is at least one of dioctyl phthalate, carboxyl-terminated nitrile rubber, hydroxyl-terminated nitrile rubber, and liquid polysulfide rubber.

[0020] Preferably, the epoxy coupling agent is glycidoxypropyltrimethoxysilane.

[0021] Preferably, the defoaming agent is a polysiloxane compound.

[0022] Preferably, the amino coupling agent is at least one of aminopropyltriethoxysilane, aminoethylaminopropyltrimethoxysilane, and aminoethylaminopropylmethyldimethoxysilane.

[0023] The present invention also relates to a method for preparing the high-performance two-component epoxy grouting adhesive for underwater cracks in concrete, which specifically comprises the following steps:

[0024] 1) Weigh each raw material by weight,

[0025] 2) Mix the modified epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, reactive diluent, and epoxy coupling agent evenly, add toughening agent, defoaming agent, and wetting dispersant and mix evenly to obtain the resin component, and store.

[0026] 3) Evenly mix the modified amine curing agent and amino coupling agent to obtain the curing agent component and store it.

[0027] The present invention has the following technical advantages:

[0028] 1. Low viscosity: The mixed viscosity of component A and component B is less than 300mPa·s (at 25°C);

[0029] 2. Good tensile properties: elongation at break ≥ 2.5%, tensile strength ≥ 60MPa;

[0030] 3. Excellent bonding performance: The tensile bonding strength of steel to C45 wet concrete is ≥3.5MPa, and the concrete fails in a cohesive manner;

[0031] 4. Excellent mechanical properties: compressive strength ≥95MPa;

[0032] 5. Good volume stability: basically no shrinkage during curing. DETAILED DESCRIPTION

[0033] In order to characterize the technical effect of the present invention, epoxy potting glue was prepared and its performance was tested. During the test, the resin component and the curing agent component were used in a mass ratio of 3:1, E-51 bisphenol A epoxy resin was selected, REF-170 bisphenol F epoxy resin was selected, ethylene glycol diglycidyl ether was selected as the reactive diluent, carboxyl-terminated nitrile rubber was selected as the toughening agent, glycidoxypropyl trimethoxysilane was selected as the epoxy coupling agent, polysiloxane compound was selected as the defoaming agent, and aminopropyl triethoxysilane was selected as the amino coupling agent. The preparation process of the modified epoxy resin is as follows: C 18 Alcohol and PDMS-OH were mixed in a molar ratio of 1:1, and 0.6% of the weight of the two catalysts DMAP was added. The mixture was reacted at 120 ° C in vacuum for 8 h to generate C 18 -PDMS ester, unreacted monomers were removed by vacuum distillation to obtain hydrophobic long-chain siloxane ester, the hydrophobic long-chain siloxane ester was reacted with epoxy resin AG-80 at a mass ratio of 1:0.5 under alkaline conditions, 12% of the mass of both γ-glycidyloxypropyltrimethoxysilane was added, and the reaction was carried out at 80°C for 3h to generate an epoxy resin-C18-PDMS network structure, 110 parts of the epoxy resin-C18-PDMS network structure was dissolved in toluene, 8 parts of KH550 were added, and 0.8 parts of catalyst boron trifluoride ethyl was added dropwise Amine, stirred at 80 ° C for 6 hours, and the solvent was removed by reduced pressure distillation to obtain the modified amine curing agent. The preparation process of the modified amine curing agent is as follows: 100 parts of polyetheramine, 15 parts of KH550, and 0.5 parts of titanate are stirred at 80 ° C for 6 hours, 35 parts of perfluorooctyl triethoxysilane are added, the temperature is raised to 120 ° C for reaction 8 hours, and the fluorine-silicon grafted polyetheramine is obtained after reduced pressure degassing, and 30 parts of hydrophobic nano-silica are added, 3000r / min high-speed shearing is carried out for 50 minutes, and 30 parts of ethylene glycol diglycidyl ether are added and mixed evenly to obtain the product.

[0034] During the test, the mixed viscosity was tested in accordance with GB / T 50728-2011, the tensile strength and elongation at break were tested in accordance with GB / T 2567-2008, the compressive strength was tested in accordance with GB / T 50728-2011, the steel-to-steel tensile shear strength was tested in accordance with GB / T 7124-2008, and the tensile bond strength of steel to C45 wet concrete was tested in accordance with GB / T 50728-2011.

[0035] Example 1

[0036] Epoxy potting glue, the resin component is composed of the following raw materials in parts by weight: 15 parts of modified epoxy resin, 40 parts of bisphenol A epoxy resin, 30 parts of bisphenol F epoxy resin, 10 parts of reactive diluent, 3 parts of toughening agent, 1 part of epoxy coupling agent, 1.5 parts of defoaming agent, 2 parts of wetting and dispersing agent; the curing agent component is composed of the following raw materials in parts by weight: 35 parts of modified amine curing agent, 1.5 parts of amino coupling agent.

[0037] After testing, the mixed viscosity (25℃) was 268mPa·s, the tensile strength was 68.35MPa, the elongation at break was 3.75%, the compressive strength was 99.15MPa, the steel-to-steel tensile shear strength was 19MPa, and the tensile bond strength of steel to C45 wet concrete was 3.90MPa.

[0038] Example 2

[0039] Epoxy potting glue, the resin component is composed of the following raw materials in parts by weight: 20 parts of modified epoxy resin, 30 parts of bisphenol A epoxy resin, 40 parts of bisphenol F epoxy resin, 13 parts of reactive diluent, 2 parts of toughening agent, 1.1 parts of epoxy coupling agent, 1.5 parts of defoaming agent, 2 parts of wetting and dispersing agent; the curing agent component is composed of the following raw materials in parts by weight: 35 parts of modified amine curing agent, 2 parts of amino coupling agent.

[0040] After testing, the mixed viscosity (25℃) was 244mPa·s, the tensile strength was 72.08MPa, the elongation at break was 4.10%, the compressive strength was 102.1MPa, the steel-to-steel tensile shear strength was 23MPa, and the tensile bond strength of steel to C45 wet concrete was 4.25MPa.

[0041] Comparative Example 1

[0042] Epoxy potting glue, the resin component is composed of the following raw materials in parts by weight: 40 parts of bisphenol A epoxy resin, 50 parts of bisphenol F epoxy resin, 13 parts of reactive diluent, 2 parts of toughening agent, 1.1 parts of epoxy coupling agent, 1.5 parts of defoaming agent, 2 parts of wetting and dispersing agent; the curing agent component is composed of the following raw materials in parts by weight: 35 parts of modified amine curing agent, 2 parts of amino coupling agent.

[0043] After testing, the mixed viscosity (25℃) was 300mPa·s, the tensile strength was 59.6MPa, the elongation at break was 2.52%, the compressive strength was 90.6MPa, the steel-to-steel tensile shear strength was 16MPa, and the tensile bond strength of steel to C45 wet concrete was 3.55MPa.

[0044] Comparative Example 2

[0045] Epoxy potting glue, the resin component is composed of the following raw materials in parts by weight: 20 parts of modified epoxy resin, 30 parts of bisphenol A epoxy resin, 40 parts of bisphenol F epoxy resin, 13 parts of active diluent, 2 parts of toughening agent, 1.5 parts of defoaming agent, 2 parts of wetting and dispersing agent; the curing agent component is composed of the following raw materials in parts by weight: 35 parts of modified amine curing agent, 2 parts of amino coupling agent.

[0046] After testing, the mixed viscosity (25℃) was 250mPa·s, the tensile strength was 66.36MPa, the elongation at break was 3.60%, the compressive strength was 93.6MPa, the steel-to-steel tensile shear strength was 18MPa, and the tensile bond strength of steel to C45 wet concrete was 3.30MPa.

[0047] Comparative Example 3

[0048] Epoxy potting glue, the resin component is composed of the following raw materials in parts by weight: 20 parts of modified epoxy resin, 30 parts of bisphenol A epoxy resin, 40 parts of bisphenol F epoxy resin, 13 parts of reactive diluent, 2 parts of toughening agent, 1.1 parts of epoxy coupling agent, 1.5 parts of defoaming agent, 2 parts of wetting and dispersing agent; the curing agent component is composed of the following raw materials in parts by weight: 35 parts of polyetheramine curing agent, 2 parts of amino coupling agent.

[0049] After testing, the mixed viscosity (25℃) was 265mPa·s, the tensile strength was 63.82MPa, the elongation at break was 3.47%, the compressive strength was 94.18MPa, the steel-to-steel tensile shear strength was 19MPa, and the tensile bond strength of steel to C45 wet concrete was 3.46MPa.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-performance two-component epoxy grouting adhesive for underwater concrete cracks, characterized in that: It is composed of resin component and curing agent component in a mass ratio of (2-4):

1. The resin component is composed of the following raw materials in parts by weight: 10-20 parts of modified epoxy resin, 20-45 parts of bisphenol A epoxy resin, 30-55 parts of bisphenol F epoxy resin, 10-15 parts of reactive diluent, 1-3 parts of toughening agent, 0.1-1.5 parts of epoxy coupling agent, 0.1-1.5 parts of defoaming agent, and 1-3 parts of wetting and dispersing agent. The modified epoxy resin is prepared by introducing a long-chain alkane into a hydrophobic group, grafting it with the epoxy resin side chain, and then grafting it with the coupling agent. The curing agent component is composed of the following raw materials in parts by weight: 30-40 parts of a modified amine curing agent and 1-2.5 parts of an amino coupling agent. The modified amine curing agent is prepared by mixing fluorosilicone grafted polyetheramine and hydrophobic nano-silica and then adding ethylene glycol diglycidyl ether.

2. The high-performance two-component epoxy grouting adhesive for underwater cracks in concrete according to claim 1, characterized in that: The modified epoxy resin preparation process is as follows: 18 Alcohol and PDMS-OH were mixed in a molar ratio of 1:(0.9-1.1), and a catalyst DMAP (0.5-0.7)% by weight of both was added and reacted in vacuum to generate C 18 -PDMS ester, unreacted monomers are removed by vacuum distillation to obtain hydrophobic long-chain siloxane ester, the hydrophobic long-chain siloxane ester is reacted with epoxy resin AG-80 at a mass ratio of 1: (0.3-0.6) under alkaline conditions, and γ-glycidyloxypropyltrimethoxysilane (10-15)% by mass of both is added, and the reaction is carried out at 80-90°C for 2-3h to produce epoxy resin-C 18 -PDMS network structure, 100-120 parts of epoxy resin-C 18 -PDMS network structure is dissolved in toluene, 6-10 parts of KH550 are added, 0.7-0.9 parts of catalyst boron trifluoride ethylamine are added dropwise, the mixture is stirred for reaction, and the solvent is removed by distillation under reduced pressure to obtain the product.

3. The high-performance two-component epoxy grouting adhesive for underwater concrete cracks according to claim 2, characterized in that: The vacuum reaction is carried out at 110-130°C for 7-9 hours, and the stirring reaction is carried out at 70-90°C for 5-8 hours.

4. The high-performance two-component epoxy grouting adhesive for underwater concrete cracks according to claim 1, characterized in that: The preparation process of the modified amine curing agent comprises the following steps: stirring 100-110 parts of polyetheramine, 10-20 parts of KH550, and 0.1-0.9 parts of titanate under heat preservation, adding 30-40 parts of perfluorooctyltriethoxysilane, heating for reaction, degassing under reduced pressure to obtain fluorosilicone grafted polyetheramine, continuously adding 25-40 parts of hydrophobic nano-silica, shearing at high speed, adding 25-35 parts of ethylene glycol diglycidyl ether, and mixing uniformly to obtain the modified amine curing agent.

5. The high-performance two-component epoxy grouting adhesive for underwater concrete cracks according to claim 4, characterized in that: The heat preservation stirring is stirring at 70-85°C for 5-8 hours, the temperature rise reaction is reacting at 115-130°C for 7-9 hours, and the high-speed shearing is high-speed shearing at 2800-3100 r / min for 40-55 minutes.

6. The high-performance two-component epoxy grouting adhesive for underwater concrete cracks according to claim 1, characterized in that: The bisphenol A epoxy resin is E-51, and the bisphenol F epoxy resin is REF-170 bisphenol F epoxy resin.

7. The high-performance two-component epoxy grouting adhesive for underwater cracks in concrete according to claim 1, characterized in that: The active diluent is at least one of alkyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, benzyl glycidyl ether, ethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and propylene glycol diglycidyl ether; and the toughening agent is at least one of dioctyl phthalate, carboxyl-terminated nitrile rubber, hydroxyl-terminated nitrile rubber, and liquid polysulfide rubber.

8. The high-performance two-component epoxy grouting adhesive for underwater cracks in concrete according to claim 1, characterized in that: The epoxy coupling agent is glycidoxypropyltrimethoxysilane, and the defoaming agent is a polysiloxane compound.

9. The high-performance two-component epoxy grouting adhesive for underwater cracks in concrete according to claim 1, characterized in that: The amino coupling agent is at least one of aminopropyltriethoxysilane, aminoethylaminopropyltrimethoxysilane, and aminoethylaminopropylmethyldimethoxysilane.

10. The method for preparing the high-performance two-component epoxy grouting adhesive for underwater cracks in concrete according to any one of claims 1 to 9, characterized in that: The steps include: 1) Weigh each raw material by weight, 2) Mix the modified epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, reactive diluent, and epoxy coupling agent evenly, add toughening agent, defoaming agent, and wetting dispersant and mix evenly to obtain the resin component, and store. 3) Evenly mix the modified amine curing agent and amino coupling agent to obtain the curing agent component and store it.