Composite air entraining agent for plateau concrete and preparation method and application thereof

Abstract

The present invention discloses a composite air entraining agent for plateau concrete and a preparation method and application thereof, belonging to the technical field of concrete. The composite air entraining agent for plateau concrete comprises the following raw materials by weight: 30-50 parts of modified air entraining agent, 5-15 parts of hard water resistant component, 1-5 parts of foam stabilizer and 30-50 parts of water. The composite air entraining agent for plateau concrete of the present invention can not only improve the working performance, crack resistance and durability of concrete, but also increase the uniformity and impermeability of concrete, effectively reduce various problems that occur in the construction process of concrete, and improve the overall quality of concrete structure. By using the composite air entraining agent for plateau concrete of the present invention, the concrete mix ratio can be optimized, the amount of admixture can be reduced, the construction cost can be reduced, and the concrete can have better working performance and improve construction efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete, and in particular relates to a composite air entraining agent for plateau concrete and a preparation method and application thereof. Background Art

[0002] There are more and more concrete projects in the Qinghai-Tibet Plateau. The construction of major projects such as the Qinghai-Tibet Highway and the Sichuan-Tibet Railway has put forward higher requirements for the durability of plateau concrete. In engineering, air entraining agents are often added to improve the pore structure of concrete and enhance the durability of concrete. However, the low pressure and low temperature climate environment in the plateau will reduce the air content of concrete and deteriorate the pore structure. Increasing the amount of air entraining agent can increase the air content of concrete, but it will increase the cost and cause large bubbles to remain in the hardened concrete, and the pore structure will still deteriorate.

[0003] The commonly used air-entraining agents are as follows: (1) Rosin: simple preparation, low price, good foaming property, large bubbles, etc.; (2) Alkylbenzene sulfonate: good foaming property, large bubbles, poor foam stability, etc.; (3) Saponin: good water solubility, easy deliquesce, good bubble structure, etc.; (4) Fatty acids and their salts: poor foaming property, small bubbles, etc. The above-mentioned types of air-entraining agents have their own shortcomings and poor adaptability in plateau concrete. Due to the low air pressure, the air-entraining agent dosage is high, the foaming property is poor, the bubbles are easy to break, and the foam stability is poor, resulting in poor foaming and foam stability. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a composite air-entraining agent for plateau concrete and its preparation method and application. In view of the climatic characteristics of low temperature and low pressure in plateau areas, the composite air-entraining agent for plateau concrete of the present invention has better adaptability and stability, and can play a better effect in plateau environments. The composite air-entraining agent for plateau concrete of the present invention can not only improve the working performance, crack resistance and durability of concrete, but also increase the uniformity and impermeability of concrete, effectively reduce various problems that occur in the construction process of concrete, and improve the overall quality of concrete structures. By using the composite air-entraining agent for plateau concrete of the present invention, the concrete mix ratio can be optimized, the amount of admixtures can be reduced, the construction cost can be reduced, and the concrete can have better working performance and improve construction efficiency.

[0005] To achieve the above object, the present invention provides a composite air-entraining agent for plateau concrete, which comprises the following raw materials in parts by weight:

[0006] 30-50 parts of modified air entraining agent, 5-15 parts of hard water resistant component, 1-5 parts of foam stabilizer and 30-50 parts of water.

[0007] Furthermore, the modified air entraining agent is prepared from rosin, tall oil and triterpenoid saponin through addition modification and graft esterification reaction.

[0008] Further, the rosin includes rosin resin, rosin resin acid (abietic acid, neoabietic acid or longifolia abietic acid), rosin amine (dehydroabietic acid) and abietic alcohol (tetrahydroabietic alcohol) and derivatives thereof;

[0009] The triterpenoid saponin is composed of aglycones, aglycones and monosaccharides, each aglycones is composed of two connected aglycones, each aglycone is connected to three or more monosaccharides, and together they form a pentacyclic triterpenoid spatial structure, which has good water solubility and strong foam stabilizing ability. However, the air entraining performance of triterpenoid saponin is poor, so the present invention utilizes rosin, tall oil, and triterpenoid saponin to prepare a modified air entraining agent through addition modification and graft esterification reaction, which can solve the problem that the air entraining performance of triterpenoid saponin is poor. At the same time, the modified air entraining agent has better foam stabilizing performance, solubility and air entraining ability, improves the bubble liquid film structure, increases the molecular layer thickness and density, and further improves the foam stabilizing performance.

[0010] Furthermore, the preparation method of the modified air-entraining agent comprises the following steps:

[0011] The rosin, tall oil and triterpenoid saponin are put into a reaction kettle, heated to 130°C until the reactants are melted, and then the mixture is stirred evenly, and the temperature is continued to be raised to 170°C, p-toluenesulfonic acid is added and nitrogen is passed through, stirred, and kept warm, and unsaturated dibasic acid is added to carry out graft esterification reaction to generate graft esterification products, and then alkylphenol polyoxyethylene ether and polyethylene glycol are added, and the temperature is raised to 210°C and kept warm. After the reaction is completed, the temperature is lowered to 65°C, and the obtained reactants are neutralized with acid and alkali, and the pH is adjusted to 9-10. At the same time, tap water is added dropwise to control the solid content of the obtained solution to 50%, and the modified air entraining agent is obtained.

[0012] Furthermore, the weight ratio of the rosin, tall oil and triterpenoid saponin is 7:1:1;

[0013] The weight ratio of p-toluenesulfonic acid to rosin is (0.5-1):70;

[0014] The weight ratio of the unsaturated dibasic acid, alkylphenol polyoxyethylene ether and polyethylene glycol is 20:20:3.

[0015] Furthermore, the unsaturated dibasic acid includes at least one of maleic acid, fumaric acid and maleic anhydride.

[0016] Furthermore, the preparation method of the modified air-entraining agent is:

[0017] 70 parts of rosin, 10 parts of tall oil and 10 parts of triterpenoid saponin were put into a reactor, and the temperature was raised to 130°C. After the reactants were melted, the temperature was further raised to 170°C, 0.5-1 parts of p-toluenesulfonic acid were added and nitrogen was passed through, stirring was started, and the temperature was kept for 1.5 hours. 20 parts of maleic acid were added and the reaction was carried out for 2.5 hours to carry out graft esterification reaction to generate graft esterification products. 20 parts of alkylphenol polyoxyethylene ether and 3 parts of polyethylene glycol were added, the temperature was raised to 210°C and the temperature was kept for 3 hours. After the reaction, the temperature was lowered to 65°C, deionized water and 30% sodium hydroxide solution were uniformly added dropwise, and the pH was adjusted to 9 to obtain a modified air entraining agent. The concentration of the modified air entraining agent was 50wt%.

[0018] Further, the hard water resistant component is sodium lauryl sulfate, alkyl glucoside, cocamidopropyl betaine, cocamidopropyl hydroxysulfobetaine or cocamidopropyl amine oxide. For example, the alkyl glucoside can be n-hexyl glucoside.

[0019] Furthermore, the foam stabilizer is polyacrylamide, polyvinyl alcohol, cellulose, modified silicone resin polyether emulsion or non-ionic foam stabilizer. The non-ionic foam stabilizer is dodecyl dimethyl amine oxide or alkyl alcohol amide. The cellulose is hydroxyethyl cellulose.

[0020] Furthermore, the preparation method of the modified silicone resin polyether emulsion is: subjecting methyl silicone resin to a hydrosilylation reaction with terminal hydroxyl olefin methyl polyether to obtain a polyether modified silicone resin, subjecting the polyether modified silicone resin to a ring-opening reaction with maleic anhydride at 130° C., and then dripping 30% sodium hydroxide solution to adjust the pH to 7, thereby obtaining a modified silicone resin polyether emulsion with a solid content of 50%.

[0021] The present invention also provides a method for preparing the composite air-entraining agent for plateau concrete, comprising the following steps:

[0022] The modified air-entraining agent is added to the hard water resistant component under stirring conditions, and a foam stabilizer and water are added, stirred evenly, and diluted to a concentration of 1-5wt% to obtain the composite air-entraining agent for plateau concrete.

[0023] Furthermore, the preparation method of the composite air-entraining agent for plateau concrete is:

[0024] At room temperature and at a rotation speed of 200 rpm, 30-50 parts of modified air-entraining agent are added to 5-15 parts of hard water resistant components and stirred for 10-15 minutes, followed by adding 1-5 parts of foam stabilizer and 30-50 parts of deionized water, and stirring is continued for 20-30 minutes. The mixture is diluted to a concentration of 1-5wt%, and the composite air-entraining agent for plateau concrete can be obtained.

[0025] The present invention also provides application of the composite air entraining agent for plateau concrete in preparing plateau concrete.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] For air entrainment of concrete in plateau areas, the main difficulty to be overcome is that under low pressure, the stability of bubbles is lower than that in normal pressure environment, the air entrainment amount decreases, and the bubble diameter increases, resulting in faster escape of bubbles in concrete. At the same time, there are a large number of saline soils and salt lakes distributed in the western plateau area, and the calcium and magnesium ion content in the water is relatively high. Hard water will inhibit the foaming ability of the air entraining agent. The modified air entraining agent provided by the present invention utilizes the foam stabilizing performance brought by the five-ring spatial structure of triterpenoid saponins themselves, and the modified rosin improves its solubility and air entraining capacity, improves the bubble liquid film structure, increases the molecular layer thickness and density, and further improves the foam stabilizing performance. At the same time, composite foam stabilizers (such as polyacrylamide, polyvinyl alcohol, cellulose, silicone polyether emulsions, non-ionic foam stabilizers, etc.) can effectively reduce the gas-liquid interfacial tension under low pressure on the plateau, further enhance the stability of bubbles, and hard water resistant components (such as sodium dodecyl sulfate, alkyl glucoside, cocamidopropyl betaine, cocamidopropyl hydroxysulfobetaine, cocamidopropyl amine oxide, etc.) can effectively resist the problem of hard water in plateau areas being difficult to entrain air. The composite air entraining agent of the present invention utilizes the synergistic effect of the three components to further reduce the CMC value, improve the problem of plateau concrete being difficult to entrain air and poor bubble stability, enable it to play the best effect, and avoid common problems in concrete construction as much as possible. DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0030] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0031] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0032] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0033] In the embodiments of the present invention, "parts" are "parts by weight" unless otherwise specified, and normal temperature refers to "25±2°C".

[0034] The raw materials of the present invention are all purchased. As an example, sodium lauryl sulfate (CAS No.: 151-21-3), n-hexyl glucoside (CAS No.: 110615-47-9), cocoyl glucoside (CAS No.: 125590-73-0), cocamidopropyl betaine (CAS No.: 61789-40-0), cocamidopropyl hydroxysulfobetaine (CAS No.: 68139-30-0) and cocamidopropylamine oxide (CAS No.: 68155-09-9) are all purchased from Shandong Yousuo Chemical Technology Co., Ltd.; maleic acid (CAS No.: 110-16-7), fumaric acid (CAS No.: 110-17-8), maleic anhydride (CAS No.: 108-31-6), alkylphenol polyoxyethylene ether (CAS No.: 14409-72-4), polyethylene glycol (CAS No.: 25322-68-3), polyacrylamide (CAS No.: 9003-05-8), hydroxyethyl cellulose (CAS No.: 9004-62-0), triterpenoid saponin (CAS No.: 110786-71-5), rosin resin (CAS No.: 8050-09-7), tall oil (CAS No.: 8002-26-4), rosin acid (CAS No.: 514-10-3), rosin amine (CAS No.: 35928-32-6) and sodium rosinate (CAS No.: 14351-66-7) were purchased from Aladdin Reagent (Shanghai) Co., Ltd.; rosin alcohol (CAS No.: 3772-55-2) was purchased from Shanghai Pupu Biopharmaceutical Technology Co., Ltd.; triterpenoid saponin air-entraining agent ST and rosin thermopolymer air-entraining agent SX were purchased from Shandong Yousuo Chemical Technology Co., Ltd.

[0035] In an embodiment of the present invention, the preparation method of the modified silicone resin polyether emulsion is as follows: methyl silicone resin and terminal hydroxyl methyl polyether are subjected to a silylation reaction to obtain a polyether modified silicone resin, the polyether modified silicone resin and maleic anhydride are subjected to a ring-opening reaction at 130°C, and then 30% sodium hydroxide solution is added dropwise to adjust the pH to 7, thereby obtaining a modified silicone resin polyether emulsion with a solid content of 50%.

[0036] The technical solution of the present invention is further illustrated by the following embodiments.

[0037] Example 1

[0038] Preparation of modified air-entraining agent: 70 parts of rosin resin, 10 parts of tall oil and 10 parts of triterpenoid saponin were put into a reactor, and the temperature was raised to 130°C. After the reactants were melted, the temperature was continued to be raised to 170°C, 0.8 parts of p-toluenesulfonic acid were added and nitrogen was passed through, stirring was turned on, and the temperature was kept for 1.5 hours. 20 parts of maleic acid were added and reacted for 2.5 hours to carry out graft esterification reaction to generate graft esterification products, and then 20 parts of alkylphenol polyoxyethylene ether and 3 parts of polyethylene glycol were added, the temperature was raised to 210°C and kept for 3 hours, and the temperature was lowered to 65°C after the reaction, and deionized water and 30% sodium hydroxide solution were uniformly added dropwise, and the pH was adjusted to 9 to obtain a modified air-entraining agent. The concentration of the modified air-entraining agent was 50wt%.

[0039] Preparation of composite air-entraining agent for plateau concrete: At room temperature and a rotation speed of 200 rpm, add 50 parts of the modified air-entraining agent prepared above to 15 parts of the hard water resistant component sodium dodecyl sulfate and stir for 12 minutes, then add 3 parts of foam stabilizer hydroxyethyl cellulose and 32 parts of deionized water, continue stirring for 25 minutes, and dilute to a concentration of 1wt% to obtain a composite air-entraining agent solution FYQ-1 for plateau concrete.

[0040] Example 2

[0041] Preparation of modified air-entraining agent: 70 parts of rosin acid, 10 parts of tall oil and 10 parts of triterpenoid saponins were put into a reactor, and the temperature was raised to 130°C. After the reactants were melted, the temperature was continued to be raised to 170°C, 1 part of p-toluenesulfonic acid was added and nitrogen was passed through, stirring was turned on, and the temperature was kept for 1.5 hours. 20 parts of maleic acid were added and reacted for 2.5 hours to carry out graft esterification reaction to generate graft esterification products, and then 20 parts of alkylphenol polyoxyethylene ether and 3 parts of polyethylene glycol were added, the temperature was raised to 210°C and kept for 3 hours, and the temperature was lowered to 65°C after the reaction, and deionized water and 30% sodium hydroxide solution were uniformly added dropwise, and the pH was adjusted to 9 to obtain a modified air-entraining agent. The concentration of the modified air-entraining agent was 50wt%.

[0042] Preparation of composite air-entraining agent for plateau concrete: At room temperature and a rotation speed of 200 rpm, add 50 parts of the modified air-entraining agent prepared above to 10 parts of the hard water resistant component sodium dodecyl sulfate and stir for 15 minutes, then add 3 parts of foam stabilizer hydroxyethyl cellulose and 37 parts of deionized water, continue stirring for 20 minutes, and dilute to a concentration of 1wt% to obtain the composite air-entraining agent solution FYQ-2 for plateau concrete.

[0043] Example 3

[0044] Preparation of modified air-entraining agent: 70 parts of rosin amine, 10 parts of tall oil and 10 parts of triterpenoid saponin were put into a reactor, and the temperature was raised to 130°C. After the reactants were melted, the temperature was further raised to 170°C, 0.5 parts of p-toluenesulfonic acid were added and nitrogen was passed through, stirring was started, and the temperature was kept for 1.5 hours. 20 parts of maleic acid were added and reacted for 2.5 hours to carry out graft esterification reaction to generate graft esterification products, and then 20 parts of alkylphenol polyoxyethylene ether and 3 parts of polyethylene glycol were added, the temperature was raised to 210°C and kept for 3 hours, and the temperature was lowered to 65°C after the reaction, and deionized water and 30% sodium hydroxide solution were uniformly added dropwise, and the pH was adjusted to 9 to obtain a modified air-entraining agent. The concentration of the modified air-entraining agent was 50wt%.

[0045] Preparation of composite air-entraining agent for plateau concrete: At room temperature and a rotation speed of 200 rpm, add 50 parts of the modified air-entraining agent prepared above to 5 parts of the hard water resistant component sodium dodecyl sulfate and stir for 10 minutes, then add 3 parts of foam stabilizer hydroxyethyl cellulose and 42 parts of deionized water, continue stirring for 30 minutes, and dilute to a concentration of 1wt% to obtain the composite air-entraining agent solution FYQ-3 for plateau concrete.

[0046] Example 4

[0047] Preparation of modified air-entraining agent: 70 parts of rosin alcohol, 10 parts of tall oil and 10 parts of triterpenoid saponin were put into a reactor, and the temperature was raised to 130°C. After the reactants were melted, the temperature was continued to be raised to 170°C, 0.8 parts of p-toluenesulfonic acid was added and nitrogen was passed through, stirring was turned on, and the temperature was kept for 1.5 hours. 20 parts of maleic acid were added and reacted for 2.5 hours to carry out graft esterification reaction to generate graft esterification products, and then 20 parts of alkylphenol polyoxyethylene ether and 3 parts of polyethylene glycol were added, the temperature was raised to 210°C and kept for 3 hours, and the temperature was lowered to 65°C after the reaction, and deionized water and 30% sodium hydroxide solution were uniformly added dropwise, and the pH was adjusted to 9 to obtain a modified air-entraining agent. The concentration of the modified air-entraining agent was 50wt%.

[0048] Preparation of composite air-entraining agent for plateau concrete: At room temperature and a rotation speed of 200 rpm, add 40 parts of the modified air-entraining agent prepared above to 5 parts of the hard water resistant component n-hexyl glucoside and stir for 10 minutes, then add 1 part of foam stabilizer hydroxyethyl cellulose and 39 parts of deionized water, continue stirring for 25 minutes, and dilute to a concentration of 1wt% to obtain a composite air-entraining agent solution FYQ-4 for plateau concrete.

[0049] Example 5

[0050] Preparation of modified air-entraining agent: 70 parts of sodium rosin acid, 10 parts of tall oil and 10 parts of triterpenoid saponin were put into a reactor, and the temperature was raised to 130°C. After the reactants were melted, the temperature was continued to be raised to 170°C, 0.8 parts of p-toluenesulfonic acid were added and nitrogen was passed through, stirring was turned on, and the temperature was kept for 1.5 hours. 20 parts of maleic acid were added and reacted for 2.5 hours to carry out graft esterification reaction to generate graft esterification products, and then 20 parts of alkylphenol polyoxyethylene ether and 3 parts of polyethylene glycol were added, the temperature was raised to 210°C and kept for 3 hours, and the temperature was lowered to 65°C after the reaction, and deionized water and 30% sodium hydroxide solution were uniformly added dropwise, and the pH was adjusted to 9 to obtain a modified air-entraining agent. The concentration of the modified air-entraining agent was 50wt%.

[0051] Preparation of composite air-entraining agent for plateau concrete: At room temperature and a rotation speed of 200 rpm, 40 parts of the modified air-entraining agent prepared above are added to 10 parts of the hard water resistant component coconut glucoside and stirred for 10 minutes. Subsequently, 1 part of the foam stabilizer hydroxyethyl cellulose and 49 parts of deionized water are added, and stirring is continued for 25 minutes. The composite air-entraining agent solution FYQ-5 for plateau concrete is obtained by diluting the mixture to a concentration of 1 wt%.

[0052] The performance of the concrete prepared with the composite air-entraining agent for plateau concrete prepared in the above embodiments was tested with reference to the test method in DL / T5150-2017 "Test Procedure for Hydraulic Concrete", with ST and SX air-entraining agents used as controls. In each embodiment, 0.004%-0.0065% of the mass of the cementitious material was added with a composite air-entraining agent for plateau concrete.

[0053] The test raw materials used in the performance test of composite air-entraining agent are as follows:

[0054] Cement: Huaxin Cement (Tibet) Co., Ltd. PO42.5 cement, specific surface area 345m 2 / kg;

[0055] Fly ash: Qingtongxia Power Plant Class I ash, fineness 45μm, sieve residue 9.0%;

[0056] Sand: Medium sand from the gravel and concrete production line of the 9th Engineering Bureau of China Hydropower, fineness modulus 2.49, stone powder content 15.0%;

[0057] Stone: Crushed stone from the sandstone and concrete system production line of the 9th Engineering Bureau of China Hydropower, small stone (5-20mm), medium stone (20-40mm), large stone (40-80mm), the weight ratio of small stone: medium stone: large stone = 30:40:30.

[0058] Concrete mix ratio during performance testing (kg / m 3 )See Table 1.

[0059] Table 1 Concrete mix ratio (kg / m3 )

[0060]

[0061] The test results of concrete properties are shown in Table 2.

[0062] Table 2 Concrete performance test results

[0063]

[0064] From the test results, it can be seen that compared with ST and SX, the air entraining effect and 1-hour air content change of the five composite air-entraining agents prepared in the embodiments of the present invention are smaller in plateau areas, and the compressive strength ratio data are also significantly better than ST and SX. This shows that under the same conditions, the composite air-entraining agent of the present invention has improved foaming and foam stability, and has a good application prospect in plateau concrete.

[0065] Example 6

[0066] The preparation method of the modified air entraining agent is the same as that in Example 1.

[0067] Preparation of composite air-entraining agent for plateau concrete: At room temperature and at a rotation speed of 200 rpm, add 30 parts of modified air-entraining agent to 10 parts of hard water resistant component cocamidopropyl betaine and stir for 12 minutes, then add 3 parts of foam stabilizer polyacrylamide and 40 parts of deionized water, continue stirring for 25 minutes, and dilute to a concentration of 1wt% to obtain the composite air-entraining agent solution FYQ-6 for plateau concrete.

[0068] Example 7

[0069] The preparation method of the modified air entraining agent is the same as that in Example 1.

[0070] Preparation of composite air-entraining agent for plateau concrete: At room temperature and at a rotation speed of 200 rpm, add 30 parts of modified air-entraining agent to 10 parts of hard water resistant component cocamidopropylamine oxide and stir for 12 minutes, then add 3 parts of foam stabilizer polyethylene glycol and 50 parts of deionized water, continue stirring for 25 minutes, and dilute to a concentration of 1wt% to obtain the composite air-entraining agent solution FYQ-7 for plateau concrete.

[0071] Example 8

[0072] The preparation method of the modified air entraining agent is the same as that in Example 1.

[0073] Preparation of composite air-entraining agent for plateau concrete: At room temperature and at a rotation speed of 200 rpm, add 30 parts of modified air-entraining agent to 10 parts of hard water resistant component cocamidopropyl hydroxysulfobetaine and stir for 12 minutes, then add 3 parts of modified silicone resin polyether emulsion and 40 parts of deionized water, continue stirring for 25 minutes, and dilute to a concentration of 1wt% to obtain the composite air-entraining agent solution FYQ-8 for plateau concrete.

[0074] Example 9

[0075] The same as Example 1, except that the foam stabilizer for preparing the composite air-entraining agent for plateau concrete is dodecyl dimethyl amine oxide, the addition amount is 5 parts, and the obtained composite air-entraining agent solution for plateau concrete is recorded as FYQ-9.

[0076] Comparative Example 1 (rosin air-entraining agent)

[0077] The preparation method of the air-entraining agent for plateau concrete is as follows: at room temperature and at a rotation speed of 200 rpm, 50 parts of rosin resin are added to 15 parts of hard water resistant component sodium dodecyl sulfate and stirred for 12 minutes, followed by adding 3 parts of foam stabilizer hydroxyethyl cellulose and 32 parts of deionized water, and stirring is continued for 25 minutes. The composite air-entraining agent solution for plateau concrete is diluted to a concentration of 1wt% to obtain the solution.

[0078] Comparative Example 2 (Triterpenoid saponin air-entraining agent)

[0079] The preparation method of the air-entraining agent for plateau concrete is as follows: at room temperature and at a rotation speed of 200 rpm, 50 parts of triterpenoid saponins are added to 15 parts of the hard water resistant component sodium dodecyl sulfate and stirred for 12 minutes, followed by adding 3 parts of foam stabilizer hydroxyethyl cellulose and 32 parts of deionized water, and continuing stirring for 25 minutes. The mixture is diluted to a concentration of 1wt% to obtain a composite air-entraining agent solution for plateau concrete.

[0080] Comparative Example 3

[0081] The preparation method of the modified air entraining agent is the same as that in Example 1.

[0082] The preparation method of the air entraining agent for plateau concrete is the same as that of Example 1, except that the hard water resistant component sodium dodecyl sulfate is not added.

[0083] The performance test results of Examples 6-9 and Comparative Examples 1-3 (testing methods are the same as above) are shown in Table 3.

[0084] Table 3 Concrete performance test results

[0085]

[0086] The above embodiments of the present invention show good use effects. The composite air-entraining agent of the present invention has good air-entraining, foam-stabilizing and dispersing properties when used in plateau areas, is easy to construct, and is economical and practical. Whether added alone or compounded in a water-reducing agent, it can be evenly dispersed. At the same time, the composite air-entraining agent of the present invention has good low-temperature solubility and admixture compatibility, and has good air-entraining and foam-stabilizing properties.

[0087] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A composite air entraining agent for plateau concrete, characterized in that: According to weight parts, it includes the following raw materials: 30-50 parts of modified air entraining agent, 5-15 parts of hard water resistant component, 1-5 parts of foam stabilizer and 30-50 parts of water; The modified air entraining agent is prepared by addition modification and graft esterification reaction of rosin, tall oil and triterpenoid saponin, comprising the following steps: mixing the rosin, tall oil and triterpenoid saponin, heating to 130° C., stirring the mixture evenly, continuing to heat to 170° C., adding p-toluenesulfonic acid and passing nitrogen, stirring, keeping warm, adding unsaturated dibasic acid, reacting, adding alkylphenol polyoxyethylene ether and polyethylene glycol, heating to 210° C. and keeping warm, cooling to 65° C. after the reaction is completed, neutralizing the obtained reactant with acid and alkali, adjusting the pH to 9-10, and simultaneously dripping water to control the solid content of the obtained solution to 50%, thereby obtaining the modified air entraining agent; The weight ratio of the rosin, tall oil and triterpenoid saponin is 7:1:1; The weight ratio of the unsaturated dibasic acid, alkylphenol polyoxyethylene ether and polyethylene glycol is 20:20:3; The hard water resistant component is sodium lauryl sulfate, alkyl glucoside, cocamidopropyl betaine, cocamidopropyl hydroxysulfobetaine or cocamidopropylamine oxide; The foam stabilizer is polyacrylamide, polyvinyl alcohol, cellulose, modified silicone resin polyether emulsion or non-ionic foam stabilizer.

2. The composite air entraining agent for plateau concrete according to claim 1, characterized in that: The rosin includes rosin resin, rosin resin acid, rosin amine or rosin alcohol and derivatives thereof.

3. The composite air entraining agent for plateau concrete according to claim 1, characterized in that: The unsaturated dibasic acid includes at least one of maleic acid, fumaric acid and maleic anhydride.

4. A method for preparing the composite air-entraining agent for plateau concrete according to any one of claims 1 to 3, characterized in that: The following steps are involved: The modified air-entraining agent is added to the hard water resistant component under stirring conditions, and a foam stabilizer and water are added, stirred evenly, and diluted to a concentration of 1-5wt% to obtain the composite air-entraining agent for plateau concrete.

5. Use of the composite air-entraining agent for plateau concrete according to any one of claims 1 to 3 in the preparation of plateau concrete.

Images