An interfacial adhesive, its preparation method and use

Abstract

The application discloses an interface adhesive as well as a preparation method and application thereof, and belongs to the technical field of concrete. A component A contains E-51 epoxy resin, elastic modulus enhancer a (a composite of single-sulfur calcium sulphoaluminate and high-sulfur calcium sulphoaluminate) and bonding enhancer b (nanoscale gel), etc.; a component B is a polyamide curing agent and a modified aromatic amine curing agent. The adhesive has an elastic modulus of about 40 GPa, is between UHPC and NC, can relieve interface stress concentration, can permeate and block microcracks at the same time, and can significantly improve bonding strength and durability. When the adhesive is prepared, the component A and the component B are stirred respectively, are mixed in proportion, and are vacuum degassed, and the adhesive is obtained. When the adhesive is constructed, the adhesive is coated on the surface of existing ordinary concrete first, and then an ultrahigh performance concrete reinforcing layer is poured.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of concrete, and particularly relates to an interfacial bonding agent as well as a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of the construction industry, ordinary concrete (NC) has become an important material for buildings and structures due to its good load-bearing performance, wide applicability, and convenience of local materials. However, over time, the load-bearing capacity and service life of ordinary concrete will gradually decrease. In addition, due to the influence of natural forces and improper construction and maintenance, ordinary concrete structures are prone to various diseases. For such disease structures, it is costly to demolish and rebuild, and reinforcement and repair is a more economical and effective disposal scheme.

[0003] As a cement-based material with ultra-high strength and ultra-high durability, ultra-high performance concrete (UHPC) is a promising new type of reinforcement material. In reinforcement engineering, it is crucial to form a reliable and firm bonding interface between UHPC and the existing ordinary concrete matrix. The quality of this bonding performance directly determines the safety and durability of the reinforcement engineering, and is also the key to the wide application of UHPC in the reinforcement field.

[0004] The interfacial bonding agent is a key material for improving and enhancing the bonding performance between the reinforcement material (such as UHPC) and the base material (such as the existing NC). After the reinforcement layer is poured, the shrinkage of the newly poured concrete will be constrained by the existing structure, thereby generating tensile stress at the interface. When this tensile stress exceeds the bonding strength of the new and old concrete interface, cracks or even cracking may occur at the interface. Harmful substances from the outside can enter the interior of the structure through these cracks, seriously damaging the durability of the reinforced structure. In addition, when the reinforced structure is subjected to external loads, the bonding interface is often in a complex state of multiple stress coupling. However, the commonly used epoxy structural adhesive has defects such as insufficient bonding strength, large temperature shrinkage deformation, low elastic modulus, high brittleness, and poor durability, which seriously restricts the safety and durability of the reinforcement engineering, and also limits the application and development of UHPC as a reinforcement material.

[0005] Therefore, it is of great significance to develop an interfacial bonding agent that can significantly improve the bonding reliability between UHPC and the existing ordinary concrete, in order to promote the wide application and development of UHPC in reinforcement engineering. SUMMARY

[0006] In view of the above technical problems, the present application provides an interfacial bonding agent as well as a preparation method and application thereof. The interfacial bonding agent can effectively improve the bonding strength of ultra-high performance concrete and existing concrete, and has the characteristics of small temperature shrinkage deformation, large elastic modulus, strong toughness, and strong durability.

[0007] To achieve the above object, the present application provides the following technical scheme:

[0008] One of the objects of the present application is to provide an interfacial adhesive comprising component A and component B.

[0009] The component A comprises, in parts by mass: 900-1100 parts of E-51 bisphenol A type epoxy resin, 100-140 parts of butyl glycidyl ether diluent, 20-50 parts of silane coupling agent, 150-250 parts of elastic modulus enhancer a, 150-250 parts of adhesion enhancer b, 15-30 parts of 2,4,6-tris(dimethylaminomethyl)phenol accelerator, 150-250 parts of nano-silica, and 200-300 parts of silicon micro powder.

[0010] The component B comprises, in parts by mass: 150-250 parts of polyamide curing agent and 100-200 parts of modified aromatic amine curing agent.

[0011] The elastic modulus enhancer a is a composite of single-sulfur type calcium aluminate sulfate and high-sulfur type calcium aluminate sulfate; and the adhesion enhancer b is a nanoscale gel.

[0012] The elastic modulus of ultra-high performance concrete is usually 45-55 GPa, while the elastic modulus of ordinary concrete is usually 30-35 GPa. The difference in elastic modulus is significant, and under the action of temperature change or external force, local stress peaks are easily generated near the interface, leading to deformation incoordination, and further causing the failure of traditional structural adhesion and the shedding of the interface. Compared with conventional structural adhesives, the core innovation of the interface adhesive of the present application lies in the addition of a unique elastic modulus enhancer a in the A component. The component contains single-sulfur calcium sulphoaluminate and high-sulfur calcium sulphoaluminate. The single-sulfur calcium sulphoaluminate has a layered structure composed of positively charged main layers and interlayer anions. After the epoxy resin macromolecules enter the layer, a strong van der Waals force is generated between the layer, and the epoxy resin and the curing agent undergo crosslinking polymerization reaction in the layer, and nanoscale composite occurs with the single-sulfur calcium sulphoaluminate layered structure. At the same time, due to the needle-like or rod-like structure of the high-sulfur calcium sulphoaluminate, the elastic modulus of the cured epoxy resin is greatly improved. This synergistic effect significantly improves the elastic modulus of the cured product, which reaches about 40 GPa. This key feature enables the adhesive of the present application to play an ideal role as a transition layer between UHPC and NC, with an elastic modulus between the two, effectively relieving the stress concentration at the interface and significantly reducing the risk of cracking and shedding of the adhesive due to fatigue, aging or stress mismatch. In addition, the adhesive of the present application also has the advantages of small surface tension and low viscosity, and can fully penetrate into the surface micropores and cracks of UHPC and NC. The adhesion enhancer b (a nanoscale gel) in the A component plays a key role in this regard, which can effectively seal the pores and microcracks on the surface of the concrete, and optimize the transition interface between the adhesive and the concrete aggregate. More importantly, it promotes the uniform dispersion of nanosilica, silica fume and unhydrated cement particles in the concrete and the dense secondary hydration reaction, thereby significantly improving the bonding strength and toughness of the interface adhesive.

[0013] Further, the mass ratio of the A component to the B component is (1-3) : 1.

[0014] Further, the preparation method of the elastic modulus enhancer a comprises the following steps: dissolving calcium nitrate tetrahydrate and aluminum nitrate nonahydrate in deionized water, adjusting the pH to alkaline, adding sodium sulfate solution dropwise under nitrogen protection, 25-45℃ and 300-400r / min stirring, and continuing to react after the dropwise addition is completed; after the reaction is completed, the solvent is removed by reduced pressure distillation, and the white precipitate is obtained by washing and drying.

[0015] Still further, the mass ratio of the calcium nitrate tetrahydrate, the aluminum nitrate nonahydrate and the deionized water is (80-120) : (70-90) : 600.

[0016] Still further, the sodium sulfate solution is prepared by mixing sodium sulfate and deionized water in a mass ratio of (10-20) : 300.

[0017] Further, the preparation method of the adhesion enhancer b comprises the following steps: dissolving calcium nitrate tetrahydrate and sodium metasilicate in deionized water, adding a suspension stabilizer dropwise under stirring at 70-80 DEG C and 2000-5000 r / min, continuing to react after the dropwise addition is completed, and neutralizing to pH=7 to obtain a milky white liquid.

[0018] Further, the mass ratio of the calcium nitrate tetrahydrate, the sodium metasilicate and the deionized water is (80-120):(20-30):300; and the suspension stabilizer is prepared from xanthan gum, triethanolamine and deionized water in a mass ratio of 1:(2-4):500.

[0019] The second object of the application is to provide a preparation method of an interfacial adhesive, comprising the following steps:

[0020] The A component raw materials are weighed according to the proportion, manually stirred to a viscous state, and then mechanically stirred at a speed of 1000-2000 r / min for 3-5 min;

[0021] The B component raw materials are weighed according to the proportion, manually stirred to a viscous state, and then mechanically stirred at a speed of 500-1000 r / min for 3-5 min;

[0022] The A component and the B component are mixed, constant temperature stirring is carried out at a speed of 1000-2000 r / min for 3-5 min, and vacuum degassing is carried out for 3-5 min to obtain the interfacial adhesive.

[0023] The third object of the application is to provide an application of the interfacial adhesive in the reinforcement of an ultra-high performance concrete-existing ordinary concrete interface.

[0024] Further, the interfacial adhesive is coated on the surface of the existing ordinary concrete during construction, and then the ultra-high performance concrete reinforcing layer is poured.

[0025] Compared with the prior art, the application has the following advantages and technical effects:

[0026] The interfacial adhesive of the application effectively alleviates the deformation incoordination between the ultra-high performance concrete and the existing ordinary concrete through elastic modulus matching, greatly reduces the interface cracking risk, and significantly enhances the overall adhesion of the new and old concretes through the unique nanoscale gel component which can penetrate into the matrix micropores, block defects and form a dense interface. The adhesive itself has the characteristics of low viscosity and long operation period, and is convenient to construct; meanwhile, the adhesive has excellent moisture and heat resistance and aging resistance, can maintain high strength and toughness in a long-term service environment, and provides a reliable and durable interface connection solution for reinforcement engineering. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which constitute a part of this specification, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this specification. The embodiments of the application, and their

[0028] Figure 1 UHPC-NC specimens prepared according to the present application. DETAILED DESCRIPTION

[0029] Various example embodiments of the application will now be described in detail with reference to the accompanying drawings. The detailed description is made in connection with the drawings, but is not intended to limit the application. The application is described in connection with the drawings, but is not intended to limit the application.

[0030] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Additionally, the use of "including," "comprising," "having," "containing," and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless otherwise indicated, the use of the approximately or about symbol (e.g., ~) is meant to encompass ± 10% of the recited value.

[0031] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice of the present application. All documents mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict between the present specification and any document incorporated by reference, the present specification will control.

[0032] Various modifications and changes can be made to the specific embodiments of the application described herein without departing from the scope or spirit of the application. Other embodiments of the application will be apparent to those of ordinary skill in the art from the description and examples presented herein. The description and examples are illustrative of the application and are not intended to limit the scope of the application in any way.

[0033] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" or variants thereof are open-ended, and include one or more steps, integers, compositions or elements listed thereafter, but not to the exclusion of any additions thereof.

[0034] The embodiments of the present application provide an interfacial adhesive, comprising a component A and a component B;

[0035] The A component comprises, by mass parts: 900-1100 parts (as an example, such as 900 parts, 1000 parts or 1100 parts) of E-51 bisphenol A type epoxy resin, 100-140 parts (as an example, such as 100 parts, 120 parts or 140 parts) of butyl glycidyl ether diluent, 20-50 parts of silane coupling agent (as an example, such as 20 parts, 35 parts or 50 parts), 150-250 parts of elastic modulus enhancer a (as an example, such as 150 parts, 200 parts or 250 parts), 150-250 parts of adhesive enhancer b (as an example, such as 150 parts, 200 parts or 250 parts), 15-30 parts of 2,4,6-tris (dimethylaminomethyl) phenol accelerator (as an example, such as 15 parts, 20 parts or 30 parts), 150-250 parts of nano-silica (as an example, such as 150 parts, 200 parts or 250 parts) and 200-300 parts of silicon micro powder (as an example, such as 200 parts, 250 parts or 300 parts);

[0036] The B component comprises, by mass parts: 150-250 parts (as an example, such as 150 parts, 200 parts or 250 parts) of polyamide curing agent and 100-200 parts (as an example, such as 100 parts, 150 parts or 200 parts) of modified aromatic amine curing agent;

[0037] The elastic modulus enhancer a is a composite of calcium sulphoaluminate of single sulfur type and calcium sulphoaluminate of high sulfur type; and the adhesive enhancer b is a nano-level gel.

[0038] In some optional embodiments of the present application, the mass ratio of the A component to the B component is (1-3) : 1. For example, in the following preferred embodiments of the present application, the mass ratio of the A component to the B component is 1:1, 2:1 or 3:1.

[0039] In some optional embodiments of the present application, the preparation method of the elastic modulus enhancer a comprises the following steps: dissolving 80-120 parts (as an example, such as 80 parts, 100 parts or 120 parts) of calcium nitrate tetrahydrate, 70-90 parts (as an example, such as 70 parts, 80 parts or 90 parts) of aluminum nitrate nonahydrate in 600 parts of deionized water, adjusting the pH to 11-13 (as an example, such as 11, 12 or 13) with a 30 wt.% NaOH solution, adding a sodium sulfate solution (consisting of 10-20 parts of sodium sulfate and 300 parts of deionized water, as an example, such as 10 parts of sodium sulfate, 15 parts of sodium sulfate or 20 parts of sodium sulfate) dropwise under nitrogen protection, 25-45℃ (as an example, such as 25℃, 35℃ or 45℃), 300-400 r / min (as an example, such as 300 r / min, 350 r / min or 400 r / min) stirring, the dropwise adding time is 4-8 h (as an example, such as 4 h, 6 h or 8 h), and the reaction is continued for 24-72 h (as an example, such as 24 h, 48 h or 72 h) after the dropwise adding is completed; after the reaction is completed, the solvent is removed by reduced pressure distillation, the white precipitate is obtained by washing with deionized water and anhydrous ethanol alternately for 4 times to remove soluble salts, and vacuum drying at 60℃ for 24 h.

[0040] In some optional embodiments of the present application, the preparation method of the bonding enhancer b comprises the following steps: dissolving 80-120 parts (as an example, such as 80 parts, 100 parts or 120 parts) of calcium nitrate tetrahydrate, 20-30 parts (as an example, such as 20 parts, 25 parts or 30 parts) of sodium metasilicate in 300 parts of deionized water, adding a suspension stabilizer (consisting of 1 part of 200,000 viscosity xanthan gum, 2-4 parts of triethanolamine and 500 parts of deionized water, as an example, such as 2 parts of triethanolamine, 3 parts of triethanolamine or 4 parts of triethanolamine) dropwise under stirring at 70-80℃ (as an example, such as 70℃, 75℃ or 80℃), 2000-5000 r / min (as an example, such as 2000 r / min, 3000 r / min or 5000 r / min), the dropwise adding time is 3 h, the reaction is continued for 2 h after the dropwise adding is completed, and the solution is neutralized to pH=7 with a 30 wt.% NaOH solution after the reaction is completed, to obtain a milky white liquid.

[0041] The present application also provides a preparation method of an interfacial bonding agent, comprising the following steps:

[0042] (1) the A component raw materials are weighed according to the proportion, manually stirred to a viscous state, and then mechanically stirred at a speed of 1000-2000 r / min (as an example, such as 1000 r / min, 1500 r / min or 2000 r / min) for 3-5 min (as an example, such as 3 min or 5 min);

[0043] The B component raw materials are weighed according to the proportion, and after manual stirring to a viscous state, mechanical stirring is carried out at a speed of 500-1000 r / min (for example, 500 r / min, 800 r / min or 1000 r / min) for 3-5 min (for example, 3 min or 5 min);

[0044] (2) Mixing A component and B component, constant temperature stirring at 1000-2000 r / min (for example, 1000 r / min, 1500 r / min or 2000 r / min) for 3-5 min (for example, 3 min or 5 min), vacuum degassing for 3-5 min (for example, 3 min or 5 min) to obtain an interfacial adhesive. The interfacial adhesive is prepared, poured into the corresponding mold, vibrated uniformly, demolded after 1d curing and placed in a cool place, and the elastic modulus thereof is tested by a universal material testing machine to be 38-42 GPa.

[0045] The interfacial adhesive provided by the application can be applied in the reinforcement of the interface between super high performance concrete and existing ordinary concrete. When the interfacial adhesive is constructed, it is coated on the surface of the existing ordinary concrete, and then the super high performance concrete reinforcing layer is poured.

[0046] Unless otherwise specified, the "room temperature" in the application refers to 25±2℃.

[0047] Unless otherwise specified, the "parts" in the application refer to mass parts.

[0048] The raw materials used in the application are all purchased on the market: E-51 bisphenol A type epoxy resin (CYD-128 model of Henan Yinghui Chemical Product Co., Ltd.); butyl glycidyl ether diluent (501 model of Guangzhou Qianan Chemical Co., Ltd.); silane coupling agent (KH-560 model of Shandong Huachen New Material Co., Ltd.); elastic modulus enhancer a, adhesion enhancer b, 2,4,6-tris (dimethylaminomethyl) phenol accelerator (DMP-30 model of the same blue new energy technology development (Shandong) group Co., Ltd.); nano silicon dioxide (A200 model of Shanghai Kaijin Chemical Co., Ltd.); silicon powder (8000 mesh model of Tao Yi New Material (Guangzhou) Co., Ltd.); polyamide curing agent (model 650 of Guangzhou Haibong Chemical Co., Ltd.); modified aromatic amine curing agent (H-113 model of Shandong Moore Chemical Co., Ltd.).

[0049] The technical solutions of the application are further described below through examples.

[0050] Example 1

[0051] A preparation method of an interfacial adhesive, the steps are as follows:

[0052] S1, preparation of A component:

[0053] (1) Preparation of elastic modulus enhancer a: In a reactor equipped with a stirrer, a dropping device and a heating device, 80 parts of calcium nitrate tetrahydrate, 70 parts of aluminum nitrate nonahydrate and 600 parts of deionized water were added, the pH of the solution was adjusted to 11 with a 30 wt.% NaOH solution, the temperature was controlled at 25°C, nitrogen was introduced for protection, the rotation speed was set at 300 r / min, and the sodium sulfate solution (consisting of 10 parts of sodium sulfate and 300 parts of deionized water) was started to be added dropwise, the dropping time was 4 h, after the dropping was completed, the stirring was continued for 24 h, after the reaction was completed, the solvent was removed by vacuum distillation to obtain a white precipitate, which was washed with deionized water and anhydrous ethanol alternately for 4 times to remove soluble salts, and vacuum dried at 60°C for 24 h to obtain the elastic modulus enhancer a;

[0054] (2) Preparation of adhesion enhancer b: In a reactor equipped with a high-speed stirrer, a dropping device and a heating device, 80 parts of calcium nitrate tetrahydrate, 20 parts of sodium metasilicate and 300 parts of deionized water were added, the temperature was controlled at 70°C, the rotation speed was set at 2000 r / min, and the suspension stabilizer (consisting of 1 part of 200,000 viscosity xanthan gum, 2 parts of triethanolamine and 500 parts of deionized water) was started to be added dropwise, the dropping time was 3 h, after the dropping was completed, the stirring was continued for 2 h, after the reaction was completed, the solution was neutralized to pH 7 with a 30 wt.% NaOH solution to obtain the milky white adhesion enhancer b;

[0055] (3) Preparation of component A: 900 parts of E-51 bisphenol A type epoxy resin, 100 parts of butyl glycidyl ether diluent, 20 parts of silane coupling agent, 150 parts of elastic modulus enhancer a, 150 parts of adhesion enhancer b, 15 parts of 2,4,6-tris(dimethylaminomethyl) phenol accelerator, 150 parts of nano silicon dioxide and 200 parts of silicon powder were mixed, first manually stirred to a viscous state, and then mechanically stirred at a speed of 1000 r / min for 3 min to obtain component A;

[0056] S2, Preparation of component B:

[0057] Component B was prepared by mixing 150 parts of polyamide curing agent and 100 parts of modified aromatic amine curing agent, first manually stirring to a viscous state, and then mechanically stirring at a speed of 500 r / min for 3 min;

[0058] S3, Component A and component B were mixed in a mass ratio of 1:1, and then vacuum degassed for 3 min after constant temperature stirring at a speed of 1000 r / min for 3 min to obtain the interfacial adhesive.

[0059] The interfacial adhesive was poured into the corresponding mold, vibrated uniformly, demolded after curing for 1 d and placed in a cool place, and the elastic modulus was tested by a universal material testing machine to be 38 GPa.

[0060] Example 2

[0061] A method for preparing an interfacial adhesive, steps as follows:

[0062] S1, preparation of component A:

[0063] (1) Preparation of elastic modulus enhancer a: in a reactor equipped with a stirrer, a dropping device and a heating device, 120 parts of calcium nitrate tetrahydrate, 90 parts of aluminum nitrate nonahydrate and 600 parts of deionized water were added, the pH of the solution was adjusted to 13 with 30 wt.% NaOH solution, the temperature was controlled at 45℃, nitrogen was introduced for protection, the rotation speed was set at 400 r / min, and sodium sulfate solution (sodium sulfate solution was composed of 20 parts of sodium sulfate and 300 parts of deionized water) was started to be added dropwise, the dropping time was 8 h, after the dropping was completed, the stirring was continued for 72 h, after the reaction was completed, the solvent was removed by reduced pressure distillation to obtain white precipitate, which was washed with deionized water and anhydrous ethanol alternately for 4 times to remove soluble salts, and vacuum dried at 60℃ for 24 h to obtain elastic modulus enhancer a;

[0064] (2) Preparation of bonding enhancer b: in a reactor equipped with a high-speed stirrer, a dropping device and a heating device, 120 parts of calcium nitrate tetrahydrate, 30 parts of sodium metasilicate and 300 parts of deionized water were added, the temperature was controlled at 80℃, the rotation speed was set at 5000 r / min, and the suspension stabilizer (the suspension stabilizer was composed of 1 part of 200,000 viscosity xanthan gum, 4 parts of triethanolamine and 500 parts of deionized water) was started to be added dropwise, the dropping time was 3 h, after the dropping was completed, the stirring was continued for 2 h, after the reaction was completed, the solution was neutralized to pH 7 with 30 wt.% NaOH solution, and a milky white bonding enhancer b was obtained;

[0065] (3) Preparation of component A: 1100 parts of E-51 bisphenol A type epoxy resin, 140 parts of butyl glycidyl ether diluent, 50 parts of silane coupling agent, 250 parts of elastic modulus enhancer a, 250 parts of bonding enhancer b, 30 parts of 2,4,6-tris (dimethylaminomethyl) phenol accelerator, 250 parts of nano silicon dioxide and 300 parts of silicon powder were mixed, first manually stirred to viscous state, and then mechanically stirred at a rotation speed of 2000 r / min for 5 min to obtain component A;

[0066] S2, preparation of component B:

[0067] The 250 parts of polyamide curing agent and 200 parts of modified aromatic amine curing agent were mixed, first manually stirred to viscous state, and then mechanically stirred at a rotation speed of 1000 r / min for 5 min to obtain component B;

[0068] S3, component A and component B were mixed in a mass ratio of 3:1, and then vacuum degassed for 5 min after constant temperature stirring at a rotation speed of 2000 r / min for 5 min to obtain an interfacial adhesive.

[0069] The interface adhesive is poured into a corresponding mold, vibrated uniformly, demolded after curing for 1 d, and placed in a cool place. A universal material testing machine is used to test the elastic modulus, which is 41 GPa.

[0070] Example 3

[0071] A preparation method of an interface adhesive, steps are as follows:

[0072] S1, preparation of component A:

[0073] (1) Preparation of elastic modulus enhancer a: in a reactor provided with a stirrer, a dropping device and a heating device, 100 parts of calcium nitrate tetrahydrate, 80 parts of aluminum nitrate nonahydrate and 600 parts of deionized water are added, the pH of the solution is adjusted to 12 with a 30wt.% NaOH solution, the temperature is controlled at 35℃, nitrogen is introduced for protection, the rotation speed is set to 350r / min, sodium sulfate solution (sodium sulfate solution is composed of 15 parts of sodium sulfate and 300 parts of deionized water) is started to be added dropwise, the dropping time is 6h, after the dropping is completed, the stirring is continued for 48h, after the reaction is completed, the solvent is removed by reduced pressure distillation to obtain white precipitate, which is washed with deionized water and anhydrous ethanol alternately for 4 times to remove soluble salts, and vacuum dried at 60℃ for 24h to obtain the elastic modulus enhancer a;

[0074] (2) Preparation of bonding enhancer b: in a reactor provided with a high-speed stirrer, a dropping device and a heating device, 100 parts of calcium nitrate tetrahydrate, 25 parts of sodium metasilicate and 300 parts of deionized water are added, the temperature is controlled at 75℃, the rotation speed is set to 3000r / min, the suspension stabilizer (the suspension stabilizer is composed of 1 part of 200,000 viscosity xanthan gum, 3 parts of triethanolamine and 500 parts of deionized water) is started to be added dropwise, the dropping time is 3h, after the dropping is completed, the stirring is continued for 2h, after the reaction is completed, the solution is neutralized to pH 7 with a 30wt.% NaOH solution, and the milky white bonding enhancer b is obtained;

[0075] (3) Preparation of component A: 1000 parts of E-51 bisphenol A type epoxy resin, 120 parts of butyl glycidyl ether diluent, 35 parts of silane coupling agent, 200 parts of elastic modulus enhancer a, 200 parts of bonding enhancer b, 20 parts of 2,4,6-tris (dimethylaminomethyl) phenol accelerator, 200 parts of nano silicon dioxide and 250 parts of silicon powder are mixed, first manually stirred to viscous state, and then mechanically stirred at a rotation speed of 1500r / min for 5min to obtain component A;

[0076] S2, preparation of component B:

[0077] 200 parts of polyamide curing agent and 150 parts of modified aromatic amine curing agent are mixed, first manually stirred to viscous state, and then mechanically stirred at a rotation speed of 800r / min for 5min to obtain component B;

[0078] S3, mixing A component and B component according to the mass ratio of 2:1, and stirring at 1500 r / min for 5 min, then vacuum degassing for 5 min to obtain the interfacial adhesive.

[0079] Pouring the interfacial adhesive into the corresponding mold, vibrating uniformly, demolding after curing for 1 d and placing in a cool place, and testing the elastic modulus of 42 GPa by using a universal material testing machine.

[0080] Example 4

[0081] A preparation method of an interfacial adhesive, the steps being as follows:

[0082] S1, preparation of A component:

[0083] (1) Preparation of elastic modulus enhancer a: in a reactor equipped with a stirrer, a dropping device and a heating device, 100 parts of calcium nitrate tetrahydrate, 80 parts of aluminum nitrate nonahydrate and 600 parts of deionized water were added, the solution pH was adjusted to 12 with 30 wt.% NaOH solution, the temperature was controlled at 35℃, nitrogen was introduced for protection, the rotation speed was set at 350 r / min, sodium sulfate solution (sodium sulfate solution was composed of 15 parts of sodium sulfate and 300 parts of deionized water) was started to be added dropwise, the dropping time was 6 h, after the dropping was completed, stirring was continued for 48 h, after the reaction was completed, the solvent was removed by reduced pressure distillation to obtain white precipitate, which was washed with deionized water and anhydrous ethanol alternately for 4 times to remove soluble salts, and vacuum dried at 60℃ for 24 h to obtain elastic modulus enhancer a;

[0084] (2) Preparation of bonding enhancer b: in a reactor equipped with a high-speed stirrer, a dropping device and a heating device, 100 parts of calcium nitrate tetrahydrate, 25 parts of sodium metasilicate and 300 parts of deionized water were added, the temperature was controlled at 75℃, the rotation speed was set at 3000 r / min, suspension stabilizer (suspension stabilizer was composed of 1 part of 200,000 viscosity xanthan gum, 3 parts of triethanolamine and 500 parts of deionized water) was started to be added dropwise, the dropping time was 3 h, after the dropping was completed, stirring was continued for 2 h, after the reaction was completed, the solution was neutralized to pH 7 with 30 wt.% NaOH solution to obtain milky white bonding enhancer b;

[0085] (3) Preparation of A component: 1000 parts of E-51 bisphenol A type epoxy resin, 120 parts of butyl glycidyl ether diluent, 35 parts of silane coupling agent, 200 parts of elastic modulus enhancer a, 200 parts of bonding enhancer b, 20 parts of 2,4,6-tris (dimethylaminomethyl) phenol accelerator, 200 parts of nano silicon dioxide and 250 parts of silicon powder were mixed, first manually stirred to viscous state, then mechanically stirred at 1500 r / min for 5 min to obtain A component;

[0086] S2, preparation of B component:

[0087] Mix 200 parts of polyamide curing agent and 150 parts of modified aromatic amine curing agent, first manually stir to viscous, then mechanically stir at 800 r / min for 5 min, to obtain component B;

[0088] S3, mix component A and component B according to the mass ratio of 3:1, and stir at 1500 r / min for 5 min, then vacuum degassing for 5 min to obtain the interfacial adhesive.

[0089] Pour the interfacial adhesive into the corresponding mold, vibrate uniformly, cure for 1 d, then demold and place in a cool place, and use a universal material testing machine to test the elastic modulus, which is 39 GPa.

[0090] Comparative Example 1

[0091] The same as Example 3, except that the elastic modulus enhancer a in step S1 is replaced by the same mass of epoxy resin toughening agent (NA03 type of Dongguan Nawei Nanometer Material Technology Co., Ltd.).

[0092] Comparative Example 2

[0093] The same as Example 3, except that the bonding enhancer b in step S2 is removed.

[0094] Comparative Example 3

[0095] A method for preparing an interfacial adhesive, the steps are as follows:

[0096] S1, preparation of component A:

[0097] (1) Preparation of elastic modulus enhancer a: the same as Example 3;

[0098] (2) Preparation of bonding enhancer b: the same as Example 3;

[0099] (3) Preparation of component A: mix 1400 parts of E-51 bisphenol A type epoxy resin, 120 parts of butyl glycidyl ether diluent, 35 parts of silane coupling agent, 200 parts of elastic modulus enhancer a, 200 parts of bonding enhancer b, 20 parts of 2,4,6-tris(dimethylaminomethyl) phenol accelerator, 50 parts of nano silicon dioxide and 50 parts of silicon powder, first manually stir to viscous, then mechanically stir at 1500 r / min for 5 min, to obtain component A;

[0100] S2, selection of component B:

[0101] Use 350 parts of polyamide curing agent as component B;

[0102] S3, mix component A and component B according to the mass ratio of 2:1, and stir at 1500 r / min for 5 min, then vacuum degassing for 5 min to obtain the interfacial adhesive.

[0103] Comparative Example 4

[0104] The same as Example 3, except that in step S3, the mass ratio of component A to component B is 4:1.

[0105] Interface adhesive performance test:

[0106] The interface adhesive performance test is performed in accordance with the relevant provisions of GB / T 50367-2013 “Code for Design of Strengthening of Concrete Structures”, GB / T 2567-2021 “Test Methods for Resin Casts”, and GB / T 7124-2008 “Determination of Tensile Shear Strength of Adhesives (Rigid Materials to Rigid Materials)”. The glue solution is prepared, the sample is formed, and the curing temperature is 23±2℃, and the relative humidity is 50±5%. The initial viscosity of the interface adhesive, the tensile strength, the compressive strength, the bending strength, and the elastic modulus of the sample after 7 days of molding are tested, and the UHPC-NC specimen is subjected to 7-day and 90-day tensile strength, splitting strength, shear strength, and 90-day temperature and humidity aging test.

[0107] The use effect of the interface adhesive is verified by the tensile strength, splitting strength, and shear strength. The preparation method of the UHPC-NC specimen is as follows:

[0108] The raw materials of the ordinary concrete (NC) are: Esheng P·O 42.5 cement, fly ash F class I, machine-made sand with a fineness modulus of 2.8, 5mm-25mm continuous gradation gravel, and an admixture dosage of 1.0wt% of the cement mass, as shown in Table 1. The admixture is mixed by mixing polycarboxylic acid water reducer (six-carbon type P6), slump retaining agent (six-carbon type C3), retarder (sodium gluconate), air entraining agent (triterpene saponin), and water in a mass ratio of 300:100:20:1:579.

[0109] Table 1 C50 ordinary concrete mix proportion (kg / m 3 )

[0110] Cement Fly ash Machine-made sand Crushed stone Water Admixture 385 95 731 1143 141 4.8

[0111] The raw materials of the ultra-high performance concrete (UHPC) are: Esheng P·O 52.5 cement, composite admixture, expansive agent, quartz sand, steel fiber, water, and admixture; wherein the composite admixture is composed of silica fume, first-grade fly ash, and mineral powder in a mass ratio of 3:2:2; the expansive agent is UEA expansive agent with aluminum sulfate, aluminum oxide, and potassium aluminum sulfate as the main expansive source; the quartz sand is composed of 20-40 mesh, 40-70 mesh, and 70-120 mesh quartz sand in a mass ratio of 2:2:1; the steel fiber is copper-plated micro-fiber steel fiber 0.2±0.02mm non-flat type. The admixture dosage is 1.5% of the total mass of the cement, composite admixture, and expansive agent. The specific see Table 2.

[0112] Table 2. Mix proportion of UHPC (kg / m 3 )

[0113] Cement Composite admixture Expanding agent Quartz sand Water Steel fiber Admixture 754 280 66 1010 187 157 16.5

[0114] UHPC-NC specimen preparation:

[0115] According to the above formula, first cast C50 concrete components, and after natural environment maintenance for 28 days, the interface is treated, the interface is brushed with steel brush, until the sand particles can be seen, then washed with clean water, and after natural drying, first brush the interface adhesive prepared in Example 3 for the first time, brush the second time after 30 minutes, the thickness of each brushing is controlled in the range of 1-1.5mm, then cast UHPC, and respectively stand at room temperature for 7 days and 90 days. The universal testing machine is used to test according to GB50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", and the specific test results are shown in Table 3.

[0116] Among them, the size of the oblique shear specimen is a prism 100mmx100mmx300mm, the size of the splitting specimen is a standard cylinder of φ150mmx300mm, and the NC and UHPC parts are both half cylinders; the tensile specimen is 100mmx100mmx300mm; the specific size is shown in Figure 1 .

[0117] Table 3. Performance test results of interface adhesive

[0118] Test item Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Initial viscosity / mPa-s 77 76 64 85 164 124 191 232 Workable time / h 1.2 1.8 1.5 1.7 0.8 0.6 1 1.1 7-day tensile strength / MPa 49.4 54.6 62.5 50.3 38.2 31.7 42.5 40.6 7-day compressive strength / MPa 92.2 108.4 115.8 102.6 72.3 65.4 86.7 78.5 7-day flexural strength / MPa 83.8 98.2 102.6 87.4 68.5 51.3 76.6 71.6 7-day elastic modulus / GPa 37.9 40.9 42.0 39.1 31.6 28.2 33.6 30.4 7-day normal temperature UHPC-NC tensile strength / MPa 7.8 8.7 9.2 8.1 4.1 3.9 5.3 4.7 7-day normal temperature UHPC-NC splitting strength / MPa 9.4 10.2 11.5 9.7 4.8 4.3 5.9 5.3 7-day normal temperature UHPC-NC shear strength / MPa 37.2 43.3 45.2 39.5 18.7 15.2 26.1 22.6 90-day normal temperature UHPC-NC tensile strength / MPa 9.9 10.6 11.4 10.3 6.1 5.4 6.7 6.3 90-day normal temperature UHPC-NC splitting strength / MPa 11.2 12.6 13.8 11.5 6.9 5.6 7.8 7.2 90-day normal temperature UHPC-NC shear strength / MPa 41.6 47.9 51.1 46.4 15.3 12.1 26.5 23.5 90-day temperature and humidity aging UHPC-NC strength reduction rate / % 1.7 1.4 1.2 1.5 21.5 23.4 9.9 8.9

[0119] As can be seen from Table 3, the interface adhesive prepared in the examples of the application has the advantages of low initial viscosity, long operable time, high stiffness, high strength, strong adhesion and good aging resistance. Compared with the data of Comparative Examples 1-4, the interface adhesive prepared in Examples 1-4 has low initial viscosity, longer operable time, higher tensile strength, compressive strength and bending strength at 7 days, higher UHPC-NC tensile strength, splitting strength and shear strength at 7 days and 90 days, and slower decrease of UHPC-NC shear strength at 90 days.

[0120] The above is only a preferred specific embodiment of the application, but the protection scope of the application is not limited thereto, any changes or replacements within the technical range disclosed by the application can be easily thought by those skilled in the art, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. An interfacial adhesive, characterized in that, It includes component A and component B; the mass ratio of component A to component B is (1-3):1; By weight, component A comprises: 900-1100 parts of E-51 bisphenol A type epoxy resin, 100-140 parts of butyl glycidyl ether diluent, 20-50 parts of silane coupling agent, 150-250 parts of elastic modulus reinforcing agent a, 150-250 parts of adhesive reinforcing agent b, 15-30 parts of 2,4,6-tris(dimethylaminomethyl)phenol accelerator, 150-250 parts of nano silica and 200-300 parts of silica powder; By weight, component B comprises: 150-250 parts polyamide curing agent and 100-200 parts modified aromatic amine curing agent; Wherein, the elastic modulus reinforcing agent a is a complex of monosulfide calcium sulfoaluminate and high-sulfide calcium sulfoaluminate; The bonding enhancer b is a nanoscale gel, and its preparation method includes the following steps: dissolving calcium nitrate tetrahydrate and sodium metasilicate in deionized water, adding a suspension stabilizer dropwise under stirring at 70-80℃ and 2000-5000r / min, continuing the reaction after the addition is complete, and neutralizing to pH=7 to obtain a milky white liquid.

2. The interfacial adhesive according to claim 1, characterized in that, The preparation method of the elastic modulus enhancer a includes the following steps: dissolving calcium nitrate tetrahydrate and aluminum nitrate nonahydrate in deionized water, adjusting the pH to alkaline, and adding sodium sulfate solution dropwise under nitrogen protection, at 25-45℃ and 300-400r / min stirring. After the addition is complete, the reaction continues. After the reaction is completed, the solvent is removed by vacuum distillation, and the product is washed and dried to obtain a white precipitate.

3. The interfacial adhesive according to claim 2, characterized in that, The mass ratio of the calcium nitrate tetrahydrate, aluminum nitrate nonahydrate, and deionized water is (80-120):(70-90):

600.

4. The interfacial adhesive according to claim 2, characterized in that, The sodium sulfate solution is prepared by mixing sodium sulfate and deionized water in a mass ratio of (10-20):

300.

5. The interfacial adhesive according to claim 1, characterized in that, The mass ratio of the calcium nitrate tetrahydrate, sodium metasilicate, and deionized water is (80-120):(20-30):300; and / or, The suspension stabilizer is prepared from xanthan gum, triethanolamine and deionized water in a mass ratio of 1:(2-4):

500.

6. A method for preparing an interfacial adhesive as described in any one of claims 1-5, characterized in that, Includes the following steps: Weigh out the raw materials of component A according to the formula, stir manually until viscous, and then mechanically stir at 1000-2000 r / min for 3-5 minutes; Weigh out the raw materials of component B according to the formula, stir manually until viscous, and then mechanically stir at 500-1000 r / min for 3-5 minutes. Mix components A and B, stir at a constant temperature of 1000-2000 r / min for 3-5 min, and then degas under vacuum for 3-5 min to obtain the interface binder.

7. The application of an interface adhesive as described in any one of claims 1-5 in the reinforcement of the interface between ultra-high performance concrete and existing ordinary concrete.

8. The application according to claim 7, characterized in that, During construction, the interface adhesive is applied to the surface of existing ordinary concrete, and then an ultra-high performance concrete reinforcement layer is poured.

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