Concrete repairing material as well as preparation method and application thereof

Abstract

The invention discloses a concrete repairing material as well as a preparation method and application thereof. The concrete repairing material comprises the following components: cement, fine sand, fly ash, silane coupling agent modified nano cellulose, carboxyl-terminated hyperbranched polyamide, a water reducing agent and a defoaming agent. The concrete repairing material prepared by the scheme of the invention can be cured in a short time, has good compressive strength, breaking strength and tensile bonding strength, low dry shrinkage rate and high corrosion resistance, and can be used for industrial large-scale application.

Description

Technical Field

[0001] This invention belongs to the field of concrete, specifically relating to a concrete repair material, its preparation method, and its application. Background Technology

[0002] In urban roads, cement concrete pavement accounts for over 95%. Over long-term use, due to the severe pressure from heavy vehicles on the concrete surface, coupled with aging and corrosion, cracks appear, and in some cases, entire sections of the concrete pavement may even peel off. Repair and maintenance of damaged pavement are necessary. If addressed promptly, simply repairing and maintaining the concrete surface can significantly extend its service life and reduce operating costs.

[0003] At present, although a lot of research has been carried out and many results have been achieved in the field of concrete crack repair materials at home and abroad, some are still in the research and development stage. Most of the crack repair materials that have been put into use are organic materials, mainly used for the repair of cracks in building concrete. These repair materials not only have strict requirements on the crack interface state, are expensive, and are prone to aging, but also have complex synthesis processes, which are not conducive to promotion and are even more difficult to meet the requirements of repairing cracks in cement concrete pavement. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a concrete repair material.

[0005] The present invention also proposes a method for preparing the above-mentioned concrete repair material.

[0006] The present invention also proposes the application of the above-mentioned concrete repair materials.

[0007] According to one aspect of the present invention, a concrete repair material is provided, the concrete repair material comprising the following components: cement, fine sand, fly ash, silane coupling agent modified nanocellulose, carboxyl-terminated hyperbranched polyamide, water-reducing agent and defoamer.

[0008] In some embodiments of the present invention, the concrete repair material comprises, by weight: 180-300 parts cement, 350-450 parts fine sand, 20-40 parts fly ash, 2-10 parts silane coupling agent modified nanocellulose, 2-10 parts carboxyl-terminated hyperbranched polyamide, 2-5 parts water-reducing agent, and 0.1-2 parts defoamer.

[0009] In some embodiments of the present invention, the concrete repair material comprises, by weight: 200-250 parts cement, 380-420 parts fine sand, 25-35 parts fly ash, 4-8 parts silane coupling agent modified nanocellulose, 2-6 parts carboxyl-terminated hyperbranched polyamide, 2-4 parts water-reducing agent, and 0.5-2 parts defoamer.

[0010] In some embodiments of the present invention, the concrete repair material comprises, by weight: 210-230 parts cement, 390-410 parts fine sand, 28-32 parts fly ash, 5-8 parts silane coupling agent modified nanocellulose, 3-5 parts carboxyl-terminated hyperbranched polyamide, 2-4 parts water-reducing agent, and 0.8-1.2 parts defoamer.

[0011] In some specific embodiments, by weight, the concrete contains 180 parts, 200 parts, 220 parts, 240 parts, 260 parts, 280 parts, 300 parts, or any value between thereof; fine sand contains 350 parts, 370 parts, 390 parts, 410 parts, 430 parts, 450 parts, or any value between thereof; fly ash contains 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, or any value between thereof; silane coupling agent modified nanocellulose contains 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, or any value between thereof; water-reducing agent contains 2 parts, 3 parts, 4 parts, or any value between thereof; and defoamer contains 0.5 parts, 1 part, 2 parts, or any value between thereof.

[0012] In some embodiments, the cement is selected from one or more of ordinary silicate cement, early-strength silicate cement, or sulfoaluminate cement.

[0013] In some embodiments, the fine sand is selected from natural fine sand.

[0014] In some embodiments, the fine sand has a fineness modulus of 1.6-2.2 and a mud content of ≤3wt%.

[0015] In some embodiments, the preparation method of the silane coupling agent modified nanocellulose is as follows:

[0016] (1) Disperse nanocellulose in a solvent to obtain a nanocellulose suspension;

[0017] (2) Add the silane coupling agent to the nanocellulose suspension and disperse it by ultrasonication to obtain the dispersed product;

[0018] (3) The dispersed product is filtered and dried sequentially to obtain the final product.

[0019] In some embodiments of the present invention, the silane coupling agent includes, but is not limited to, methyltrimethoxysilane.

[0020] In some embodiments of the present invention, the mass ratio of the silane coupling agent to the nanocellulose is 1:(3-5); specifically, it can be 1:3, 1:4, or 1:5.

[0021] In some embodiments of the present invention, the ultrasonic dispersion time is 30-50 min.

[0022] In some embodiments of the present invention, the ultrasonic dispersion time is 35-45 min.

[0023] In some embodiments of the present invention, the ultrasonic dispersion time is 38-42 min.

[0024] In some embodiments of the present invention, the temperature of the ultrasonic dispersion is 40-60°C.

[0025] In some embodiments of the present invention, the temperature of the ultrasonic dispersion is 45-55°C.

[0026] In some embodiments of the present invention, the temperature of the ultrasonic dispersion is 48-52°C.

[0027] In some embodiments, the water-reducing agent is selected from one or more of naphthalene-based water-reducing agents or polycarboxylate water-reducing agents.

[0028] In some embodiments, the defoamer includes silicone defoamers or polyether defoamers.

[0029] According to a second aspect of the present invention, a method for preparing the above-mentioned concrete repair material is provided, the method comprising the following steps: mixing the above-mentioned components to obtain the material.

[0030] According to a third aspect of the invention, an application of the above-described concrete repair material is provided, wherein the application is in the preparation of concrete.

[0031] In some embodiments of the present invention, the concrete has any of the following functions:

[0032] 1) High compressive strength;

[0033] 2) High flexural strength;

[0034] 3) Corrosion resistant;

[0035] 4) High tensile bond strength;

[0036] 5) Low shrinkage rate.

[0037] In some embodiments of the present invention, the application is in the preparation of concrete repair materials.

[0038] According to a fourth aspect of the present invention, a method for repairing concrete cracks is provided, the method comprising the following steps: applying the above-mentioned concrete repair material to repair concrete cracks.

[0039] According to some embodiments of the present invention, at least the following beneficial effects are achieved: The concrete repair material prepared by the present invention comprises the following components: cement, fine sand, fly ash, silane coupling agent modified nanocellulose, carboxyl-terminated hyperbranched polyamide, water-reducing agent, and defoamer; wherein, fly ash reacts with calcium hydroxide in cement to form stable hydration products, thereby improving the density and corrosion resistance of concrete; the silane coupling agent modified nanocellulose, through modification with silane coupling agent, enhances the compatibility between nanocellulose and cement matrix, improves the adhesion between the two, and can effectively improve the mechanical properties, crack resistance, toughness, and reduce shrinkage of the repair material; the carboxyl-terminated hyperbranched polyamide can improve the bonding performance of concrete, reduce the agglomeration of cement particles, enhance the mechanical properties of cement matrix, and synergistically reduce the ground crack shrinkage of concrete, improve flexural strength and corrosion resistance, together with silane coupling agent modified nanocellulose. Through the synergistic effect of the components, a concrete repair material that can be prepared in a short time, has good compressive strength, flexural strength, tensile bond strength, low drying shrinkage, and high corrosion resistance can be prepared for large-scale industrial application. Detailed Implementation

[0040] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0041] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0042] In the description of this invention, the use of terms such as "first," "second," etc., is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0043] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0044] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has 'a' parts by mass and component B has 'b' parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (where K is any number representing a multiplier). It is important to understand that, unlike mass fractions, the sum of the mass parts of all components is not limited to 100 parts.

[0045] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0046] Material:

[0047] The silicate cement is ordinary silicate cement P·O 42.5.

[0048] The fly ash is Grade I fly ash, purchased from Jining Hengzhi New Building Materials Co., Ltd.;

[0049] The fine sand is single-graded dry natural river sand with a fineness modulus of 1.6-2.2 and a mud content of ≤3wt%, provided by Beijing Hengying Environmental Protection Technology Co., Ltd.

[0050] Nanocellulose, specifically nanocellulose CNF, was purchased from Wuhan Kangqiong Biomedical Co., Ltd.

[0051] The carboxyl-terminated hyperbranched polyamide was prepared according to the method of Example 1 in Patent Publication No. CN102382314B.

[0052] The polycarboxylate superplasticizer is a high-efficiency polycarboxylate superplasticizer produced by Chongqing Kezhijie New Materials Co., Ltd., with a solid content of 23%.

[0053] The defoamer is 8850 defoamer.

[0054] Example 1

[0055] This embodiment prepares a concrete repair material, which is composed of the following raw materials in parts by weight: 220 parts of 42.5 silicate cement, 400 parts of fine sand, 30 parts of fly ash, 6 parts of silane coupling agent modified nanocellulose, 5 parts of carboxyl-terminated hyperbranched polyamide, 3 parts of polycarboxylate superplasticizer, and 1 part of 8850 defoamer.

[0056] The preparation method of silane coupling agent modified nanocellulose is as follows:

[0057] (1) Slowly disperse nanocellulose in 50 times its weight of deionized water, stir evenly to form a nanocellulose suspension;

[0058] (2) Add the silane coupling agent (methyltrimethoxysilane) to the nanocellulose suspension (the mass ratio of silane coupling agent to nanocellulose is 1:4), and set the solution temperature to 50℃.

[0059] (3) The above mixed solution is fully dispersed by ultrasonication for 40 minutes;

[0060] (4) The dispersed product was filtered and dried at 60°C to obtain silane coupling agent modified nanocellulose.

[0061] The concrete repair material is prepared by mixing the above-mentioned 42.5 silicate cement, fine sand, fly ash, silane coupling agent modified nanocellulose, carboxyl-terminated hyperbranched polyamide, polycarboxylate superplasticizer, and 8850 defoamer in a certain proportion.

[0062] Method of using the concrete repair material:

[0063] (1) Clean up the dust, dirt and oil stains in the area to be repaired, which may affect the bonding strength between the repair material and the area to be repaired; remove loose and broken concrete blocks, and widen or deepen narrow cracks or shallow surface pits; wet the area to be repaired with clean water.

[0064] (2) Mix the concrete repair material with water at a weight ratio of 100:18, spread it evenly on the repair area, smooth it out, and then compact it with a plate vibrator.

[0065] Example 2

[0066] This embodiment prepares a concrete repair material composed of the following raw materials in parts by weight: 220 parts of 42.5 silicate cement, 400 parts of fine sand, 30 parts of fly ash, 5 parts of silane coupling agent modified nanocellulose, 6 parts of carboxyl-terminated hyperbranched polyamide, 3 parts of polycarboxylate superplasticizer, and 1 part of 8850 defoamer.

[0067] The specific preparation and usage methods are the same as in Example 1.

[0068] Example 3

[0069] This embodiment prepares a concrete repair material, which is composed of the following raw materials in parts by weight: 220 parts of 42.5 silicate cement, 400 parts of fine sand, 30 parts of fly ash, 8 parts of silane coupling agent modified nanocellulose, 3 parts of carboxyl-terminated hyperbranched polyamide, 3 parts of polycarboxylate superplasticizer, and 1 part of 8850 defoamer.

[0070] The specific preparation and usage methods are the same as in Example 1.

[0071] Comparative Example 1

[0072] This comparative example prepared a concrete repair material, which differs from Example 1 only in that it does not contain silane coupling agent modified nanocellulose.

[0073] The specific preparation and usage methods are the same as in Example 1.

[0074] Comparative Example 2

[0075] This comparative example prepared a concrete repair material, which differs from Example 1 only in that it does not contain carboxyl-terminated hyperbranched polyamide.

[0076] The specific preparation and usage methods are the same as in Example 1.

[0077] Comparative Example 3

[0078] This comparative example prepared a concrete repair material, which differed from Example 1 only in that the silane coupling agent modified nanocellulose was replaced with an equal amount of unmodified nanocellulose.

[0079] The specific preparation and usage methods are the same as in Example 1.

[0080] Test case

[0081] Compressive strength, flexural strength and corrosion resistance tests

[0082] The concrete repair materials prepared in each example and comparative example were tested according to the test methods specified in JC / T 2381-2016 and GB / T50082-2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete".

[0083] Table 1

[0084]

[0085] The results are shown in Table 1. As can be seen from the table, the concrete repair material prepared by the present invention can be cured in a short time and has good compressive strength, flexural strength, tensile bond strength, low shrinkage rate and high corrosion resistance.

[0086] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A concrete repair material, characterized in that, The concrete repair material comprises the following components: cement, fine sand, fly ash, silane coupling agent modified nanocellulose, carboxyl-terminated hyperbranched polyamide, water reducing agent and defoaming agent.

2. The concrete repair material of claim 1, wherein, The concrete repair material comprises, by weight: cement 180-300 parts, fine sand 350-450 parts, fly ash 20-40 parts, silane coupling agent modified nanocellulose 2-10 parts, carboxyl-terminated hyperbranched polyamide 2-10 parts, water reducing agent 2-5 parts and defoaming agent 0.1-2 parts.

3. The concrete repair material of claim 1, wherein, The cement is selected from one or more of ordinary portland cement, early strength portland cement or sulphoaluminate cement; And / or, the fine sand is selected from natural fine sand; Preferably, the fine sand has a fineness modulus of 1.6-2.2 and a clay content ≤3wt%.

4. The concrete repair material of claim 1, wherein, The preparation method of the silane coupling agent modified nanocellulose is as follows: (1) dispersing nanocellulose in a solvent to obtain a nanocellulose suspension; (2) adding a silane coupling agent to the nanocellulose suspension, ultrasonic dispersion to obtain a dispersed product; (3) sequentially filtering and drying the dispersed product to obtain the silane coupling agent modified nanocellulose. Preferably, the mass ratio of the silane coupling agent to the nanocellulose is 1:(3-5).

5. The concrete repair material of claim 1, wherein, The water reducing agent is selected from one or more of naphthalene-based water reducing agent or polycarboxylic acid water reducing agent; And / or, the defoaming agent comprises silicone defoaming agent or polyether defoaming agent.

6. A method of preparing a concrete repair material as claimed in any one of claims 1 to 5, characterised in that, The preparation method comprises the following steps: mixing the above components to obtain the concrete repair material.

7. Use of the concrete repair material according to any one of claims 1-5 in the preparation of concrete.

8. Use according to claim 7, characterized in that, The concrete has any one of the following functions: 1) high compressive strength; 2) high flexural strength; 3) corrosion resistance; 4) high tensile bond strength; 5) low shrinkage.

9. Use of the concrete repair material according to any one of claims 1-5 in the preparation of concrete repair material.

10. A method of repairing a concrete crack, characterized by, The method comprises the following steps: using the concrete repair material according to any one of claims 1-5 for concrete crack repair.

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