High-performance concrete in plateau environment with large temperature difference and preparation method thereof

Abstract

The application discloses high-performance concrete in a highland large-temperature-difference environment and a preparation method thereof, relates to the field of concrete, and solves the problems of accelerated performance deterioration of concrete under strong freezing and thawing and short service life of part of engineering by stirring cement, coarse and fine aggregates, a water reducing agent, a bubble stabilizer and mixing water, dispersively adding fly ash, silicon powder and a water retaining agent in the stirring process; the high hydrophobicity of the water retaining agent and the bubble stabilizer and high-intensity prevention of ice crystal growth are utilized to reduce the destructive power of the concrete structure caused by the change of ice formation and thawing of water components in the pore structure of the concrete, the ice layer can be thawed under the highland condition, the ice layer cannot be formed, and other methods do not waste manpower and material resources and cause damage to the concrete; the water reducing agent is added to reduce the porosity of the concrete, especially capillary porosity, so that the durability of the concrete is improved.

Description

Technical Field

[0001] This invention relates to the field of concrete, specifically to a high-performance concrete and its preparation method for high-altitude environments with large temperature differences. Background Technology

[0002] High-altitude regions are characterized by thin air, low air pressure, high annual average radiation, large daily temperature differences, dry climate with little rain and strong winds, and widespread seasonal permafrost. Under these conditions, concrete is constantly subjected to the effects of high altitude, strong winds, snow, ice, and frost, with more than 300 freeze-thaw cycles per year. During the day, strong solar radiation causes the ice in the concrete to melt, while at night, the temperature drops, causing the pore water in the concrete to freeze and expand. Under the strong freeze-thaw action, the performance of concrete deteriorates rapidly, and some projects have a service life of less than two years. Therefore, freeze-thaw damage has become the primary issue for the durability of concrete in high-altitude regions. Cement concrete is a non-homogeneous system composed of coarse and fine aggregates, cement, water, and gases contained within it. The high-altitude environment inevitably affects the degree of action of concrete raw materials, thereby reducing concrete performance, increasing harmful pores inside the concrete, accelerating the erosion of various water and gas environments, and ultimately significantly reducing the impermeability of concrete.

[0003] The impermeability of cement concrete is mainly improved through three aspects: crack resistance, increased density, and optimized pore structure. Common methods include using air-entraining, waterproof, or impermeable admixtures to completely block the capillary channels in the concrete, thereby improving impermeability. For every 1000m increase in altitude, the relative atmospheric pressure decreases by 12%, and in most plateau areas, the atmospheric pressure is only 30%-50% of that in plains areas. Under these conditions, the stability of air bubbles deteriorates, and their lifespan is shortened by about 50%. The dosage of air-entraining agents increases exponentially, making air entrainment in concrete difficult, and the air content is only about 50% of that at atmospheric pressure. The time loss increases by about 3 times, which greatly weakens the concrete's ability to resist freeze-thaw damage. The concrete is also prone to segregation and bleeding, which increases pumping resistance, reduces concrete strength, and reduces the number of air bubbles per unit volume to only about 35% of that at normal pressure. This seriously reduces the concrete's durability properties such as freeze resistance, causing the concrete to absorb water and freeze inside. The melting water from the ice will cause the concrete to peel off. In addition, since the concrete surface often freezes in high-altitude areas, failure to remove the ice will seriously affect personal safety. However, the use of various de-icing substances and methods on the ice surface may not only affect the quality of the concrete structure, but also consume a lot of manpower and resources. Summary of the Invention

[0004] To overcome the aforementioned technical problems, the present invention aims to provide a high-performance concrete and its preparation method for high-altitude environments with large temperature differences.

[0005] (1) First, mix cement, coarse and fine aggregates, water-reducing agent, bubble stabilizer and mixing water. During the mixing process, add fly ash, silica fume and water-retaining agent separately. Then add polyether modified organosilicon additive and mix evenly to obtain high-performance concrete in the high-altitude large temperature difference environment. This solves the problem that the performance of concrete deteriorates faster under strong freeze-thaw action and the service life of some projects is less than two years.

[0006] (2) Tetramethylhexanediamine was dissolved in a round-bottom flask containing methanol. Methyl 4-pentenoate was added dropwise to a constant pressure dropping funnel to obtain intermediate A. Intermediate A was dissolved in a round-bottom flask containing methanol. Then tetramethylhexanediamine was added and reacted under water bath conditions to obtain intermediate B. Intermediate B was added to a three-necked round-bottom flask containing chloroform. Triethylamine acid-binding agent was added to the three-necked flask. 4-(trifluoromethyl)benzenesulfonyl fluoride was added to the three-necked flask to react and obtain the water-retaining agent. This solved the problems of high mud content in concrete sand and gravel, high content of manufactured sand and gravel and stone powder, low adhesive content, low grade, bleeding, grouting, poor sand exposure in flowing concrete, and water line problems after pumped concrete set.

[0007] (3) Weigh ethylene glycolamine and dissolve it in N,N-dimethylacetamide, then transfer it to a three-necked flask. Weigh 3-n-propylglutaric anhydride and dissolve it in N,N-dimethylacetamide to a constant-pressure dropping funnel, then add it dropwise to a three-necked flask to obtain intermediate C. Add intermediate C to the three-necked flask, add a catalyst and a dehydrating agent to the three-necked flask, weigh 1,3,5-cyclohexanetriol, dissolve it in N,N-dimethylacetamide, transfer it to a constant-pressure dropping funnel, and add it dropwise to a three-necked flask to obtain intermediate D. Weigh intermediate D and dissolve it in N,N-dimethylacetamide, then transfer it to a three-necked flask to obtain intermediate D. The mixture was transferred to a three-necked flask, where a catalyst and dehydrating agent were added. Rosin acid was weighed and dissolved in N,N-dimethylacetamide, and then added dropwise to the three-necked flask using a constant-pressure dropping funnel to obtain the bubble stabilizer. This stabilizer solves the problem of decreased bubble stability and reduced number of bubbles per unit volume in high-altitude environments, which severely reduces the durability of concrete, such as its frost resistance. This leads to internal water absorption and freezing of the concrete, and failure to remove the ice can seriously affect personal safety. However, the use of various de-icing substances and methods on the ice surface can not only affect the quality of the concrete structure but also consume a lot of manpower and resources.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] A high-performance concrete for high-altitude environments with large temperature differences comprises the following components in parts by weight:

[0010] 28-40 parts cement, 15-20 parts fly ash, 5-10 parts silica fume, 58-90 parts fine aggregate, 98-170 parts coarse aggregate, 0.5-1.4 parts water-reducing agent, 0.05-3.0 parts bubble stabilizer, 0.5-1 part water-retaining agent, 0.05-2 parts polyether-modified organosilicon additive, and 10-22 parts mixing water;

[0011] The high-performance concrete for this high-altitude, high-temperature-difference environment is prepared through the following process:

[0012] S1: First, mix the cement, coarse and fine aggregates, water-reducing agent, air-bubble stabilizer and mixing water;

[0013] S2: Fly ash, silica fume and water-retaining agent are added separately during the mixing process. After mixing for 3-6 hours, polyether-modified organosilicon additives are added and mixed evenly to obtain high-performance concrete for high-altitude environments with large temperature differences.

[0014] As a further aspect of the present invention: the water-retaining agent is prepared by the following steps:

[0015] S21: Dissolve tetramethylhexanediamine in a round-bottom flask containing methanol and stir at 25-30℃ for 15-30 min to ensure thorough mixing. Add methyl 4-pentenoate to a constant-pressure dropping funnel at a dropping rate of 10-30 s / drop. After the addition is complete, place the reaction mixture in a constant-temperature magnetically stirred water bath at 25-30℃ and react for 24-36 h. After the reaction is complete, remove the solvent methanol and excess methyl acrylate by vacuum distillation at 50℃ and 133.3 Pa to obtain intermediate A.

[0016] The chemical reaction formula is as follows:

[0017]

[0018] S22: Dissolve intermediate A in a round-bottom flask containing methanol and stir at 25-30℃ for 15-30 min to ensure complete dissolution. Then add tetramethylhexanediamine and stir until homogeneous. React the reaction mixture in a water bath at 25-30℃ for 24-36 h. Remove the methanol in the reaction mixture by rotary evaporation at 50℃ and 133.3 Pa to obtain intermediate B.

[0019] The chemical reaction formula is as follows:

[0020]

[0021] S23: Under a nitrogen atmosphere, intermediate B is added to a three-necked round-bottom flask containing chloroform and stirred for 15-30 min to dissolve it completely. Then, triethylamine acid-binding agent is added to the three-necked flask and stirring is continued for 15-30 min. Then, 4-(trifluoromethyl)benzenesulfonyl fluoride is added to the three-necked flask under an ice-water bath at 0-4℃ and reacted for 2-5 h. The temperature is raised to 40-60℃ and the reaction is continued for 6-8 h. The mixture is then vacuum dried in an oven at 80-100℃ for 12-24 h to obtain the water-retaining agent.

[0022] The chemical reaction formula is as follows:

[0023]

[0024]

[0025] As a further aspect of the present invention: the ratio of tetramethylhexanediamine, methanol, and methyl 4-pentenoate in step S21 is 26.7g:50mL:141.9g.

[0026] As a further aspect of the present invention: the ratio of intermediate A, methanol, and tetramethylhexanediamine used in step S22 is 83.5g:100mL:289.5g.

[0027] As a further aspect of the present invention: the ratio of intermediate B, chloroform, triethylamine acid binder, and 4-(trifluoromethyl)benzenesulfonyl fluoride in step S23 is 3.8g:20mL:0.9g:22.8g.

[0028] As a further aspect of the present invention: the bubble stabilizer is prepared by the following steps:

[0029] S61: Weigh ethylene glycolamine and dissolve it in N,N-dimethylacetamide. Stir to dissolve and transfer to a three-necked flask. Purge with nitrogen and turn on the magnetic stirrer. Weigh 3-n-propylglutaric anhydride and dissolve it in N,N-dimethylacetamide. Transfer to a constant pressure dropping funnel and add it dropwise to the three-necked flask. Control the dropping rate at 2-3 drops / s. After the addition is complete, place the mixture at room temperature for 8-10 hours. After the reaction is complete, use a rotary evaporator to remove the solvent and unreacted monomer by vacuum distillation to obtain intermediate C.

[0030] The chemical reaction formula is as follows:

[0031]

[0032] S62: Add intermediate C to a three-necked flask, turn on the magnetic stirrer, introduce nitrogen gas, add p-toluenesulfonic acid as a catalyst and toluene as a dehydrating agent to the three-necked flask, weigh 1,3,5-cyclohexanetriol, dissolve it completely with N,N-dimethylacetamide, transfer it to a constant pressure dropping funnel, add it dropwise to the three-necked flask, and start heating to 150-180℃ at the same time. Turn on the reflux condenser, and reflux will be generated in the spherical condenser. After the dropwise addition is completed, keep the temperature constant and continue the reaction for 24-36 hours until no liquid drips. Remove the solvent by vacuum distillation using a rotary evaporator to obtain intermediate D;

[0033] The chemical reaction formula is as follows:

[0034]

[0035]

[0036] S63: Weigh intermediate D, dissolve it completely in N,N-dimethylacetamide, transfer it to a three-necked flask, turn on the stirrer, introduce nitrogen gas, add p-toluenesulfonic acid as a catalyst and toluene as a dehydrating agent to the three-necked flask, weigh rosin acid, dissolve it in N,N-dimethylacetamide with stirring, and add it dropwise to the three-necked flask using a constant pressure dropping funnel, heat to 220-250℃ to react, turn on the cooling water, and continue the reaction for 12-24 hours until no more droplets fall, then remove the solvent by vacuum distillation to obtain the bubble stabilizer.

[0037] The chemical reaction formula is as follows:

[0038]

[0039] As a further embodiment of the present invention: the ratio of ethylene glycolamine to 3-n-propylglutaric anhydride in step S61 is 77.1g:156.2g; the catalyst in step S62 is p-toluenesulfonic acid; the dehydrating agent is toluene; and the ratio of intermediate C, catalyst, dehydrating agent, and 1,3,5-cyclohexanetriol is 232.3g:0.10g:36mL:132.2g.

[0040] As a further aspect of the present invention: the catalyst in step S63 is p-toluenesulfonic acid, the dehydrating agent is toluene, and the ratio of intermediate D, catalyst, dehydrating agent and rosin acid is 245.6g:3g:20mL:204g.

[0041] As a further aspect of the present invention: the fine aggregate is manufactured sand, the coarse aggregate is crushed stone, the water-reducing agent is one or more of the following: high-performance polycarboxylate water-reducing agent, naphthalene-based high-efficiency water-reducing agent and aminosulfonate-based high-efficiency water-reducing agent, mixed in any proportion, and the mixing water is river water.

[0042] A method for preparing high-performance concrete under high-altitude and large temperature difference environments includes the following steps:

[0043] S1: First, mix the cement, coarse and fine aggregates, water-reducing agent, air-bubble stabilizer and mixing water;

[0044] S2: Fly ash, silica fume and water-retaining agent are added separately during the mixing process. After mixing for 3-6 hours, polyether-modified organosilicon additives are added and mixed evenly to obtain high-performance concrete for high-altitude environments with large temperature differences.

[0045] The beneficial effects of this invention are:

[0046] (1) This invention is made by mixing cement, coarse and fine aggregates, water-reducing agent, bubble stabilizer and mixing water, and dispersing fly ash, silica powder and water-retaining agent during the mixing process, and then adding polyether modified organosilicon additives. After mixing evenly, high-performance concrete under the large temperature difference environment of the plateau is obtained. The high hydrophobicity of water-retaining agent and bubble stabilizer strongly inhibits the growth of ice crystals, reduces the destructive force on the concrete structure caused by the changes in the freezing and thawing of water in the pore structure of the concrete, can melt the ice layer under plateau conditions, so that it cannot form an ice layer, and there is no waste of manpower and material resources or damage to the concrete as with other methods. By adding water-reducing agent, the porosity of the concrete is reduced, especially the capillary porosity, thereby improving the durability of the concrete.

[0047] (2) Tetramethylhexanediamine was dissolved in a round-bottom flask containing methanol. Methyl 4-pentenoate was added dropwise to a constant-pressure dropping funnel to obtain intermediate A. Intermediate A was dissolved in a round-bottom flask containing methanol, and then tetramethylhexanediamine was added. The reaction was carried out under water bath conditions to obtain intermediate B. Under a nitrogen atmosphere, intermediate B was added to a three-necked round-bottom flask containing chloroform. Triethylamine acid-binding agent was then added to the three-necked flask. 4-(trifluoromethyl)benzenesulfonyl fluoride was added to the three-necked flask to react and obtain the water-retaining agent. This water-retaining agent has a highly reactive dendritic macromolecular structure, and its three-dimensional structure and branching gaps provide... It provides ample space and has active end groups such as hydroxyl, amino, and ester bonds that can provide more reaction sites, making the various components of concrete more dispersed and stable. This water-retaining agent can significantly reduce concrete water loss, and the organic molecules can improve the adhesion of concrete, ensuring that concrete does not segregate during the storage process. It can give concrete good workability, wrapping properties, and fluidity, without segregation or bleeding, and improve the surface tension of the colloid without adversely affecting the fluidity of concrete. It does not entrain air or retard setting, and can ensure that there is no bleeding on the surface of concrete during the hardening process. It is widely compatible with water-reducing agents such as ethers, esters, naphthalenes, and aliphatic agents, and does not separate when compounded.

[0048] (3) Weigh ethylene glycolamine and dissolve it in N,N-dimethylacetamide, then transfer it to a three-necked flask. Weigh 3-n-propylglutaric anhydride and dissolve it in N,N-dimethylacetamide, then transfer it to a constant-pressure dropping funnel and add it dropwise to a three-necked flask to obtain intermediate C. Add intermediate C to the three-necked flask, add a catalyst and a dehydrating agent to the three-necked flask, weigh 1,3,5-cyclohexanetriol, dissolve it in N,N-dimethylacetamide, transfer it to a constant-pressure dropping funnel, and add it dropwise to a three-necked flask to obtain intermediate D. Weigh intermediate D, dissolve it in N,N-dimethylacetamide, transfer it to a three-necked flask, add a catalyst and a dehydrating agent to the three-necked flask, and weigh rosin acid... N,N-dimethylacetamide is dissolved and added dropwise to a three-necked flask using a constant-pressure dropping funnel to obtain the bubble stabilizer. This bubble stabilizer can introduce bubbles into concrete and can remain stably present inside the hardened concrete without breaking. After the bubble stabilizer forms an adsorption layer on the surface, it can be regarded as forming a film. Due to the intermolecular attraction, the bubbles in this film have good mechanical strength. After the bubble stabilizer molecules are regularly distributed on both sides of the formed molecular liquid film, the like charges of the molecules generate repulsive forces, making it difficult for the bubbles to approach each other due to repulsion, thus providing conditions for bubble stability and achieving the purpose of improving bubble stability. Detailed Implementation

[0049] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0050] Example 1:

[0051] This embodiment describes a high-performance concrete for high-altitude environments with large temperature differences, comprising the following components by weight:

[0052] 28 parts cement, 15 parts fly ash, 5 parts silica fume, 58 parts fine aggregate, 98 parts coarse aggregate, 0.5 parts water-reducing agent, 0.05 parts bubble stabilizer, 1 part water-retaining agent, 0.05 parts polyether-modified organosilicon additive, and 10 parts mixing water.

[0053] The high-performance concrete for this high-altitude, high-temperature-difference environment is prepared through the following process:

[0054] S1: First, mix the cement, coarse and fine aggregates, water-reducing agent, air-bubble stabilizer and mixing water;

[0055] S2: Fly ash, silica fume and water-retaining agent are added separately during the mixing process, and the mixture is stirred for 3 hours. Then, polyether-modified organosilicon additives are added and stirred evenly to obtain high-performance concrete for this high-altitude environment with large temperature difference.

[0056] The water-retaining agent is prepared by the following steps:

[0057] S21: Dissolve 26.7 g of tetramethylhexanediamine in a round-bottom flask containing 50 mL of methanol, and stir at 25 °C for 15 min to ensure thorough mixing. Add 141.9 g of methyl 4-pentenoate to a constant pressure dropping funnel at a dropping rate of 10 s / drop. After the addition is complete, place the reaction mixture in a constant temperature magnetically stirred water bath at 25 °C and react for 24 h. After the reaction is complete, remove the solvent methanol and excess methyl acrylate by vacuum distillation at 50 °C and 133.3 Pa to obtain intermediate A.

[0058] S22: Dissolve 83.5g of intermediate A in a round-bottom flask containing 100mL of methanol, stir at 25℃ for 15min to ensure complete dissolution, then add 289.5g of tetramethylhexanediamine, stir evenly, and react the reaction mixture in a water bath at 25℃ for 24h. Remove the methanol in the reaction mixture by rotary evaporation at 50℃ and 133.3Pa to obtain intermediate B;

[0059] S23: Under a nitrogen atmosphere, 3.8 g of intermediate B was added to a three-necked round-bottom flask containing 20 mL of chloroform and stirred for 15 min to dissolve it completely. Then, 0.9 g of triethylamine acid-binding agent was added to the three-necked flask and stirred for another 15 min. Then, under an ice-water bath at 0 °C, 22.8 g of 4-(trifluoromethyl)benzenesulfonyl fluoride was added to the three-necked flask and reacted for 2 h. The temperature was raised to 40 °C and the reaction was continued for 6 h. The mixture was then vacuum dried in an oven at 80 °C for 12 h to obtain the water-retaining agent.

[0060] The bubble stabilizer is prepared by the following steps:

[0061] S61: Weigh 77.1g of ethylene glycolamine and dissolve it in 100mL of N,N-dimethylacetamide. Stir to dissolve and transfer to a three-necked flask. Purge with nitrogen gas and turn on the magnetic stirrer. Weigh 156.2g of 3-n-propylglutaric anhydride and dissolve it in 100mL of N,N-dimethylacetamide. Transfer to a constant pressure dropping funnel and add it dropwise to the three-necked flask. Control the dropping rate at 2 drops / s. After the addition is complete, let it react at room temperature for 8 hours. After the reaction is complete, remove the solvent and unreacted monomer by vacuum distillation using a rotary evaporator to obtain intermediate C.

[0062] S62: Add 232.3g of intermediate C to a three-necked flask, turn on the magnetic stirrer, and introduce nitrogen gas. Add 0.10g of p-toluenesulfonic acid as a catalyst and 36mL of toluene as a dehydrating agent to the three-necked flask. Weigh 132.2g of 1,3,5-cyclohexanetriol and dissolve it completely in 100mL of N,N-dimethylacetamide. Transfer the solution to a constant pressure dropping funnel and add it dropwise to the three-necked flask. Simultaneously, start heating to 150℃ and turn on the reflux condenser. Reflux is generated in the spherical condenser. After the addition is complete, keep the temperature constant and continue the reaction for 24h until no liquid drips. Remove the solvent by vacuum distillation using a rotary evaporator to obtain intermediate D.

[0063] S63: Weigh 245.6g of intermediate D, dissolve it completely in 100mL of N,N-dimethylacetamide, transfer it to a three-necked flask, turn on the stirrer, introduce nitrogen gas, add 3g of p-toluenesulfonic acid as a catalyst and 20mL of toluene as a dehydrating agent to the three-necked flask, weigh 204g of rosin acid, dissolve it in 100mL of N,N-dimethylacetamide by stirring, and add it dropwise to the three-necked flask using a constant pressure dropping funnel, heat to 220℃ and react, turn on the cooling water, continue the reaction for 12h until no more droplets fall, then remove the solvent by vacuum distillation to obtain the bubble stabilizer.

[0064] Example 2:

[0065] This embodiment describes a high-performance concrete for high-altitude environments with large temperature differences, comprising the following components by weight:

[0066] 28 parts cement, 15 parts fly ash, 5 parts silica fume, 80 parts fine aggregate, 150 parts coarse aggregate, 0.5 parts water-reducing agent, 1.0 part bubble stabilizer, 0.5 parts water-retaining agent, 0.05 parts polyether-modified organosilicon additive, and 10 parts mixing water;

[0067] The high-performance concrete for this high-altitude, high-temperature-difference environment is prepared through the following process:

[0068] S1: First, mix the cement, coarse and fine aggregates, water-reducing agent, air-bubble stabilizer and mixing water;

[0069] S2: Fly ash, silica fume and water-retaining agent are added separately during the mixing process, and the mixture is stirred for 3 hours. Then, polyether-modified organosilicon additives are added and stirred evenly to obtain high-performance concrete for this high-altitude environment with large temperature difference.

[0070] The water-retaining agent is prepared by the following steps:

[0071] S21: Dissolve 26.7 g of tetramethylhexanediamine in a round-bottom flask containing 50 mL of methanol, and stir at 25 °C for 15 min to ensure thorough mixing. Add 141.9 g of methyl 4-pentenoate to a constant pressure dropping funnel at a dropping rate of 10 s / drop. After the addition is complete, place the reaction mixture in a constant temperature magnetically stirred water bath at 25 °C and react for 24 h. After the reaction is complete, remove the solvent methanol and excess methyl acrylate by vacuum distillation at 50 °C and 133.3 Pa to obtain intermediate A.

[0072] S22: Dissolve 83.5g of intermediate A in a round-bottom flask containing 100mL of methanol, stir at 25℃ for 15min to ensure complete dissolution, then add 289.5g of tetramethylhexanediamine, stir evenly, and react the reaction mixture in a water bath at 25℃ for 24h. Remove the methanol in the reaction mixture by rotary evaporation at 50℃ and 133.3Pa to obtain intermediate B;

[0073] S23: Under a nitrogen atmosphere, 3.8 g of intermediate B was added to a three-necked round-bottom flask containing 20 mL of chloroform and stirred for 15 min to dissolve it completely. Then, 0.9 g of triethylamine acid-binding agent was added to the three-necked flask and stirred for another 15 min. Then, under an ice-water bath at 0 °C, 22.8 g of 4-(trifluoromethyl)benzenesulfonyl fluoride was added to the three-necked flask and reacted for 2 h. The temperature was raised to 40 °C and the reaction was continued for 6 h. The mixture was then dried under vacuum in an oven at 100 °C for 24 h to obtain the water-retaining agent.

[0074] The bubble stabilizer is prepared by the following steps:

[0075] S61: Weigh 77.1g of ethylene glycolamine and dissolve it in 100mL of N,N-dimethylacetamide. Stir to dissolve and transfer to a three-necked flask. Purge with nitrogen gas and turn on the magnetic stirrer. Weigh 156.2g of 3-n-propylglutaric anhydride and dissolve it in 100mL of N,N-dimethylacetamide. Transfer to a constant pressure dropping funnel and add it dropwise to the three-necked flask. Control the dropping rate at 3 drops / s. After the addition is complete, let it react at room temperature for 10h. After the reaction is complete, remove the solvent and unreacted monomer by vacuum distillation using a rotary evaporator to obtain intermediate C.

[0076] S62: Add 232.3g of intermediate C to a three-necked flask, turn on the magnetic stirrer, and introduce nitrogen gas. Add 0.10g of p-toluenesulfonic acid as a catalyst and 36mL of toluene as a dehydrating agent to the three-necked flask. Weigh 132.2g of 1,3,5-cyclohexanetriol and dissolve it completely in 100mL of N,N-dimethylacetamide. Transfer the solution to a constant pressure dropping funnel and add it dropwise to the three-necked flask. At the same time, start heating to 180℃ and turn on the reflux condenser. Reflux is generated in the spherical condenser. After the addition is complete, keep the temperature constant and continue the reaction for 36h until no liquid drips. Remove the solvent by vacuum distillation using a rotary evaporator to obtain intermediate D.

[0077] S63: Weigh 245.6g of intermediate D, dissolve it completely in 100mL of N,N-dimethylacetamide, transfer it to a three-necked flask, turn on the stirrer, introduce nitrogen gas, add 3g of p-toluenesulfonic acid as a catalyst and 20mL of toluene as a dehydrating agent to the three-necked flask, weigh 204g of rosin acid, dissolve it in 100mL of N,N-dimethylacetamide by stirring, and add it dropwise to the three-necked flask using a constant pressure dropping funnel, heat to 250℃ and react, turn on the cooling water, continue the reaction for 24h until no more droplets fall, then remove the solvent by vacuum distillation to obtain the bubble stabilizer.

[0078] Example 3:

[0079] This embodiment describes a high-performance concrete for high-altitude environments with large temperature differences, comprising the following components by weight:

[0080] 40 parts cement, 20 parts fly ash, 10 parts silica fume, 90 parts fine aggregate, 170 parts coarse aggregate, 1.4 parts water-reducing agent, 3.0 parts bubble stabilizer, 1 part water-retaining agent, 2 parts polyether-modified organosilicon additive, and 22 parts mixing water;

[0081] The high-performance concrete for this high-altitude, high-temperature-difference environment is prepared through the following process:

[0082] S1: First, mix the cement, coarse and fine aggregates, water-reducing agent, air-bubble stabilizer and mixing water;

[0083] S2: Fly ash, silica fume and water-retaining agent are added separately during the mixing process, and the mixture is stirred for 6 hours. Then, polyether-modified organosilicon additives are added and stirred evenly to obtain high-performance concrete for this high-altitude environment with large temperature difference.

[0084] The water-retaining agent is prepared by the following steps:

[0085] S21: Dissolve 26.7 g of tetramethylhexanediamine in a round-bottom flask containing 50 mL of methanol, and stir at 30 °C for 30 min to ensure thorough mixing. Add 141.9 g of methyl 4-pentenoate to a constant pressure dropping funnel at a dropping rate of 30 s / drop. After the addition is complete, place the reaction mixture in a 30 °C constant temperature magnetically stirred water bath and react for 36 h. After the reaction is complete, remove the solvent methanol and excess methyl acrylate by vacuum distillation at 50 °C and 133.3 Pa to obtain intermediate A.

[0086] S22: Dissolve 83.5g of intermediate A in a round-bottom flask containing 100mL of methanol, stir at 30℃ for 30min to ensure complete dissolution, then add 289.5g of tetramethylhexanediamine, stir evenly, and react the reaction mixture in a 30℃ water bath for 36h. Remove the methanol in the reaction mixture by rotary evaporation at 50℃ and 133.3Pa to obtain intermediate B;

[0087] S23: Under a nitrogen atmosphere, 3.8 g of intermediate B was added to a three-necked round-bottom flask containing 20 mL of chloroform and stirred for 30 min to dissolve it completely. Then, 0.9 g of triethylamine acid-binding agent was added to the three-necked flask and stirred for another 30 min. Then, under an ice-water bath at 4 °C, 22.8 g of 4-(trifluoromethyl)benzenesulfonyl fluoride was added to the three-necked flask and reacted for 5 h. The temperature was raised to 60 °C and the reaction was continued for 8 h. The mixture was then vacuum dried in an oven at 100 °C for 24 h to obtain the water-retaining agent.

[0088] The bubble stabilizer is prepared by the following steps:

[0089] S61: Weigh 77.1g of ethylene glycolamine and dissolve it in 100mL of N,N-dimethylacetamide. Stir to dissolve and transfer to a three-necked flask. Purge with nitrogen gas and turn on the magnetic stirrer. Weigh 156.2g of 3-n-propylglutaric anhydride and dissolve it in 100mL of N,N-dimethylacetamide. Transfer to a constant pressure dropping funnel and add it dropwise to the three-necked flask. Control the dropping rate at 3 drops / s. After the addition is complete, let it react at room temperature for 10h. After the reaction is complete, remove the solvent and unreacted monomer by vacuum distillation using a rotary evaporator to obtain intermediate C.

[0090] S62: Add 232.3g of intermediate C to a three-necked flask, turn on the magnetic stirrer, and introduce nitrogen gas. Add 0.10g of p-toluenesulfonic acid as a catalyst and 36mL of toluene as a dehydrating agent to the three-necked flask. Weigh 132.2g of 1,3,5-cyclohexanetriol and dissolve it completely in 100mL of N,N-dimethylacetamide. Transfer the solution to a constant pressure dropping funnel and add it dropwise to the three-necked flask. At the same time, start heating to 180℃ and turn on the reflux condenser. Reflux is generated in the spherical condenser. After the addition is complete, keep the temperature constant and continue the reaction for 36h until no liquid drips. Remove the solvent by vacuum distillation using a rotary evaporator to obtain intermediate D.

[0091] S63: Weigh 245.6g of intermediate D, dissolve it completely in 100mL of N,N-dimethylacetamide, transfer it to a three-necked flask, turn on the stirrer, introduce nitrogen gas, add 3g of p-toluenesulfonic acid as a catalyst and 20mL of toluene as a dehydrating agent to the three-necked flask, weigh 204g of rosin acid, dissolve it in 100mL of N,N-dimethylacetamide by stirring, and add it dropwise to the three-necked flask using a constant pressure dropping funnel, heat to 250℃ and react, turn on the cooling water, continue the reaction for 24h until no more droplets fall, then remove the solvent by vacuum distillation to obtain the bubble stabilizer.

[0092] Comparative Example 1:

[0093] The difference between Comparative Example 1 and Example 1 is that no bubble stabilizing agent is added;

[0094] Comparative Example 2:

[0095] The difference between Comparative Example 2 and Example 1 is that no water-retaining agent is added;

[0096] Comparative Example 3:

[0097] Comparative Example 3 used commercially available concrete.

[0098] Performance testing

[0099] The concrete of Examples 1-3 and Comparative Examples 1-3 was tested, and the pressure impermeability test design level was P6;

[0100]

[0101] The test results are shown in the table below:

[0102] As shown in the table above, the compressive strength of Example 7d reached 60.2-60.4 MPa, the 7d compressive strength of Comparative Example 1 was 38.8 MPa, the 7d compressive strength of Comparative Example 2 was 36.4 MPa, and the 7d compressive strength of Comparative Example 3 was 48.5 MPa. The compressive strength of Example 10d reached 73.4-73.6 MPa, the 10d compressive strength of Comparative Example 1 was 53.4 MPa, the 10d compressive strength of Comparative Example 2 was 51.2 MPa, and the 10d compressive strength of Comparative Example 3 was 56.4 MPa. The compressive strength of Example 28d reached 79.3-79.5 MPa, the 28d compressive strength of Comparative Example 1 was 57.3 MPa, the 28d compressive strength of Comparative Example 2 was 54.2 MPa, and the 28d compressive strength of Comparative Example 3 was 59.8 MPa. The elastic modulus of Example 7d reached 3.37 × 10⁻⁶ MPa. 4 MPa, the 7-day elastic modulus of Comparative Example 1 is 2.69 × 10 MPa. 4 MPa, the 7-day elastic modulus of Comparative Example 2 is 2.64 × 10 MPa. 4 MPa, the 7-day elastic modulus of Comparative Example 3 is 2.98 × 10 MPa. 4 MPa, the elastic modulus of Example 10d reached 3.57 × 10 MPa. 4 MPa, the 10d elastic modulus of Comparative Example 1 is 2.82 × 10 MPa. 4 MPa, the 10d elastic modulus of Comparative Example 2 is 2.80 × 10 MPa. 4 MPa, the 10d elastic modulus of Comparative Example 3 is 3.04 × 10 MPa. 4 MPa, the elastic modulus of Example 28d reached 3.72 × 10 MPa. 4 MPa, the 28-day elastic modulus of Comparative Example 1 is 3.03 × 10 MPa. 4 MPa, the 28-day elastic modulus of Comparative Example 2 is 3.00 × 10 MPa. 4 MPa, the 28-day elastic modulus of Comparative Example 3 is 3.37 × 10 MPa. 4 MPa. All data in the examples are better than those in the comparative examples, indicating that the water-retaining agent and bubble stabilizer prepared by the present invention, when added to concrete, give the concrete material superior mechanical properties.

[0103] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0104] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A high-performance concrete for high-altitude environments with large temperature differences, characterized in that, Includes the following components by weight: 28-40 parts cement, 15-20 parts fly ash, 5-10 parts silica fume, 58-90 parts fine aggregate, 98-170 parts coarse aggregate, 0.5-1.4 parts water-reducing agent, 0.05-3.0 parts bubble stabilizer, 0.5-1 part water-retaining agent, 0.05-2 parts polyether-modified organosilicon additive, and 10-22 parts mixing water; The high-performance concrete for this high-altitude, high-temperature-difference environment is prepared through the following process: S1: First, mix the cement, coarse and fine aggregates, water-reducing agent, air-bubble stabilizer and mixing water; S2: Fly ash, silica fume and water-retaining agent are added separately during the mixing process, and then polyether-modified organosilicon additives are added and mixed evenly to obtain high-performance concrete for this high-altitude environment with large temperature difference. The water-retaining agent is prepared by the following steps: S21: Tetramethylhexanediamine was dissolved in a round-bottom flask containing methanol, and methyl 4-pentenoate was added dropwise to a constant-pressure dropping funnel. After the reaction was completed, intermediate A was obtained. S22: Dissolve intermediate A in a round-bottom flask containing methanol, stir to dissolve, then add tetramethylhexanediamine, and react under water bath conditions to obtain intermediate B; S23: Under a nitrogen atmosphere, intermediate B is added to a three-necked round-bottom flask containing chloroform and stirred to dissolve. Then, triethylamine acid-binding agent is added to the three-necked flask and stirring is continued. Then, under ice-water bath conditions, 4-(trifluoromethyl)benzenesulfonyl fluoride is added to the three-necked flask to react and obtain the water-retaining agent. The ratio of tetramethylhexanediamine, methanol, and methyl 4-pentenoate in step S21 is 26.7g:50mL:141.9g; In step S22, the ratio of intermediate A, methanol, and tetramethylhexanediamine is 83.5g:100mL:289.5g. In step S23, the ratio of intermediate B, chloroform, triethylamine acid binder, and 4-(trifluoromethyl)benzenesulfonyl fluoride is 3.8 g: 20 mL: 0.9 g: 22.8 g. The bubble stabilizer is prepared by the following steps: S61: Weigh ethylene glycolamine and dissolve it in N,N-dimethylacetamide, stir to dissolve, transfer to a three-necked flask, introduce nitrogen gas, turn on the magnetic stirrer, weigh 3-n-propylglutaric anhydride and dissolve it in N,N-dimethylacetamide, transfer to a constant pressure dropping funnel, add it dropwise to the three-necked flask, and after the reaction is complete, intermediate C is obtained; S62: Add intermediate C to a three-necked flask, turn on the magnetic stirrer, introduce nitrogen gas, add catalyst and dehydrating agent to the three-necked flask, weigh 1,3,5-cyclohexanetriol, dissolve it with N,N-dimethylacetamide, transfer it to a constant pressure dropping funnel, and add it dropwise to the three-necked flask to obtain intermediate D; S63: Weigh intermediate D and dissolve it in N,N-dimethylacetamide, transfer it to a three-necked flask, turn on the stirrer, introduce nitrogen gas, add catalyst and dehydrating agent to the three-necked flask, weigh rosin acid and dissolve it in N,N-dimethylacetamide, and add it dropwise to the three-necked flask using a constant pressure dropping funnel to obtain the bubble stabilizer; In step S61, the ratio of ethylene glycolamine to 3-n-propylglutaric anhydride is 77.1g:156.2g. In step S62, the catalyst is p-toluenesulfonic acid, the dehydrating agent is toluene, and the ratio of intermediate C, catalyst, dehydrating agent, and 1,3,5-cyclohexanetriol is 232.3g:0.10g:36mL:132.2g. The catalyst in step S63 is p-toluenesulfonic acid, the dehydrating agent is toluene, and the ratio of intermediate D, catalyst, dehydrating agent and rosin acid is 245.6g:3g:20mL:204g.

2. The high-performance concrete for high-altitude environments with large temperature differences according to claim 1, characterized in that, The fine aggregate is manufactured sand, the coarse aggregate is crushed stone, the water-reducing agent is one or a mixture of two or more of the following: high-performance polycarboxylate water-reducing agent, naphthalene-based high-efficiency water-reducing agent, and aminosulfonate-based high-efficiency water-reducing agent, in any proportion, and the mixing water is river water.

3. A method for preparing high-performance concrete under high-altitude, large-temperature-difference conditions according to any one of claims 1-2, characterized in that, Includes the following steps: S1: First, mix the cement, coarse and fine aggregates, water-reducing agent, air-bubble stabilizer and mixing water; S2: Fly ash, silica fume and water-retaining agent are added separately during the mixing process, and then polyether-modified organosilicon additives are added and mixed evenly to obtain high-performance concrete for high-altitude environments with large temperature differences.

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