A C70 high performance concrete

Abstract

The application relates to a C70 high-performance concrete and relates to the concrete field, which comprises the following components in mass fractions: cement 300-400 parts, mineral powder 100-120 parts, medium sand 500-600 parts, gravel 800-900 parts, methyl cellulose ether 3-5 parts, modified toughening and durability agent 80-120 parts, composite modified fiber 30-40 parts and water 120-150 parts. The application has the effects of improving the anti-cracking performance, the compressive performance and the tensile performance of the concrete, the concrete can keep good working performance for a long time, and the concrete has good durability.

Description

Technical Field

[0001] This application relates to the field of concrete, and in particular to a C70 high-performance concrete. Background Technology

[0002] High-performance concrete has become an important direction in concrete technology development in recent years. Technicians improve the physical and mechanical properties, workability, and structural performance of concrete by selecting raw materials and designing mix proportions. High-quality materials and strict production processes are used to create concrete that is easy to pour, does not segregate, has stable mechanical properties, high early strength, and is tough. It is particularly suitable for high-rise buildings, bridges, and building structures exposed to harsh environments.

[0003] However, high-strength concrete can experience durability issues under long-term use and harsh environments. High-strength concrete expands and contracts with temperature changes, and its shrinkage is greater than that of ordinary concrete. This generates internal stress, leading to cracks and affecting its durability, thus requiring improvement. Summary of the Invention

[0004] To improve the durability of high-strength concrete, this application provides a C70 high-performance concrete.

[0005] This application provides a C70 high-performance concrete using the following technical solution: A C70 high-performance concrete comprises the following components in parts by weight: 300-400 parts cement 100-120 parts of mineral powder 500-600 portions of medium sand 800-900 pieces of crushed stone 3-5 parts of methylcellulose ether Modified toughening and durability agent 80-120 parts 30-40 parts of composite modified fiber 120-150 parts water.

[0006] By adding modified toughening and durability agents, the strength of concrete can be increased, its crack resistance can be improved, and thus the durability of C70 high-performance concrete can be enhanced. The composite modified fibers, through modification treatment, improve fiber dispersibility and compatibility, which helps the composite fibers better enhance the crack resistance and impact resistance of concrete. The composite modified fibers can work synergistically with the modified toughening and durability agents to improve the tensile strength, compressive strength, and durability of C70 concrete. Through the mutual cooperation and synergistic effect of the various components in the above formula, the prepared C70 concrete has good crack resistance, tensile strength, and compressive strength, can maintain good workability for a long time, and has good durability.

[0007] Preferably, the raw materials for preparing the modified toughening and durability agent include graphene oxide-terminated polyoxyethylene ether, composite monomers, and modified fly ash.

[0008] Graphene oxide-terminated polyoxyethylene ether has good dispersibility and reactivity. It can polymerize with composite monomers and modified fly ash to form a cross-linked network, which improves the toughness and strength of C70 high-performance concrete, thereby enhancing its crack resistance and durability. Modified fly ash has good dispersibility and compatibility. As a rigid skeleton in the polymer network, the modified fly ash gives the network structure obtained by combining organic and inorganic components good toughness and crack resistance, which can improve the compressive strength, tensile strength and durability of C70 concrete.

[0009] Preferably, the raw materials for preparing the graphene oxide-terminated polyoxyethylene ether include tocotrienol polyoxyethylene ether and activated graphene oxide.

[0010] By end-capping activated graphene oxide with tocotrienol polyoxyethylene ether, graphene oxide can achieve good dispersibility after the end-capping reaction due to the steric hindrance effect brought by the tocotrienol polyoxyethylene ether. The tocotrienol polyoxyethylene ether has abundant active groups and good reactivity. It can undergo cross-linking polymerization with other components in the modified toughening and durability agent to form a polymer network with high toughness and strength, thereby improving the crack resistance, compressive strength and tensile strength of C70 concrete.

[0011] Preferably, the raw materials for preparing the tocotrienol polyoxyethylene ether include tocotrienol and ethylene oxide.

[0012] Tocotrienols react with ethylene oxide to produce tocotrienol polyoxyethylene ethers. Tocotrienols can regulate the hydration reaction of concrete, slow down the shrinkage rate of concrete, and thus reduce the generation of cracks in concrete. Tocotrienols can also react with cementitious matrix, which increases the bonding performance of polymer network and other components in concrete, thereby improving the compressive strength and density of concrete.

[0013] Preferably, the mass ratio of the tocotrienol polyoxyethylene ether to the activated graphene oxide is 1:(0.003-0.005).

[0014] The modified toughening and durable agent prepared according to the above mass ratio has good durability, compressive strength and tensile strength.

[0015] Preferably, the composite monomers include acrylic acid, acrylamide, and 2-acrylamide-2-methylpropanesulfonic acid.

[0016] Acrylic acid and graphene oxide-terminated polyoxyethylene ether undergo in-situ polymerization, while acrylamide and 2-acrylamide-2-methylpropanesulfonic acid also polymerize to form a three-dimensional cross-linked polymer network. Modified fly ash is uniformly dispersed within this network, creating a structure that interweaves a rigid skeleton with a flexible network. This polymer network enables a synergistic effect between the two, improving the density and toughness of concrete by filling the micropores. This enhances the stability and shrinkage resistance of the concrete system, thereby increasing its compressive strength, tensile strength, and durability. 2-Acrylamide-2-methylpropanesulfonic acid, as a functional monomer, enhances the compatibility of the modified toughening and durability agent, improves the impermeability of the polymer network, reduces the penetration of harmful substances, slows down hydration, and lowers the likelihood of concrete cracking.

[0017] Preferably, the raw materials for preparing the composite modified fiber include composite fiber, silane-modified nano-alumina, and alkynyl polyethylene glycol acrylate.

[0018] Composite fibers exhibit excellent crack resistance. Silane-modified nano-alumina, through silane modification, improves the dispersibility of nano-alumina, allowing for better compatibility with composite fibers and enhancing the tensile and compressive strength of the composite modified fibers. Acetyl polyethylene glycol acrylate enhances the compatibility and dispersibility of composite modified fibers, improving the uniformity and stability of concrete. Acetyl polyethylene glycol acrylate also exhibits good reactivity, increasing the active sites of composite modified fibers, enabling the fiber network and polymer network to better combine and synergistically enhance the crack resistance, compressive strength, and tensile strength of C70 concrete.

[0019] Preferably, the composite fiber includes chopped basalt fiber, polyvinyl alcohol fiber, and polyacrylonitrile fiber.

[0020] Short-cut basalt fibers, polyvinyl alcohol fibers, and polyacrylonitrile fibers can effectively control the propagation of concrete cracks and improve the crack resistance of concrete. Through the complementary properties of the three composite fibers, they form a fiber network structure in concrete, disperse external forces, increase internal strength, and work synergistically with the polymer network formed by the modified toughening and durability agent to improve the durability, compressive strength, and tensile strength of C70 concrete.

[0021] Preferably, the mass ratio of the composite fiber, silanized nano-alumina, and alkynyl polyethylene glycol acrylate is 1:(0.008-0.016):0.05.

[0022] The composite modified fibers prepared according to the above mass ratio have good dispersibility and reactivity, which can further improve the durability, compressive strength and tensile strength of concrete.

[0023] Preferably, the C70 high-performance concrete is prepared using the following steps: Cement, mineral powder, modified toughening and durability agent, composite modified fiber and water are mixed evenly to obtain cement premix; Medium sand, crushed stone, methyl cellulose ether and composite modified fiber are mixed and dispersed into cement premix to obtain concrete mix; after the concrete mix is ​​poured and cured, C70 high-performance concrete is obtained.

[0024] The concrete prepared according to the above steps has good durability, compressive strength and tensile strength.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. By adding modified toughening and durability agents, the strength of concrete can be increased, its crack resistance can be improved, and thus the durability of C70 high-performance concrete can be enhanced. The composite modified fibers, through modification treatment, improve fiber dispersibility and compatibility, which helps the composite fibers better enhance the crack resistance and impact resistance of concrete. The composite modified fibers can work synergistically with the modified toughening and durability agents to improve the tensile strength, compressive strength, and durability of C70 concrete. Through the mutual cooperation and synergistic effect between the various components in the above formula, the prepared C70 concrete has good crack resistance, tensile strength, and compressive strength, can maintain good workability for a long time, and has good durability.

[0026] 2. Graphene oxide-terminated polyoxyethylene ether has good dispersibility and reactivity. It can polymerize with composite monomers and modified fly ash to form a cross-linked network, which improves the toughness and strength of C70 high-performance concrete, thereby improving crack resistance and durability. Modified fly ash has good dispersibility and compatibility. As a rigid skeleton in the polymer network, the network structure obtained by combining organic and inorganic components has good toughness and crack resistance, which can improve the compressive strength, tensile strength and durability of C70 concrete.

[0027] 3. Composite fibers exhibit excellent crack resistance; silane-modified nano-alumina, through silane modification, improves the dispersibility of nano-alumina, allowing for better compatibility with composite fibers and enhancing the tensile and compressive strength of the composite modified fibers; alkynyl polyethylene glycol acrylate enhances the compatibility and dispersibility of composite modified fibers, improving the uniformity and stability of concrete. Alkynyl polyethylene glycol acrylate possesses good reactivity, increasing the active sites of the composite modified fibers, enabling the fiber network and polymer network to better combine and synergistically enhance the crack resistance, compressive strength, and tensile strength of C70 concrete. Detailed Implementation

[0028] This application discloses a C70 high-performance concrete. All raw materials, unless otherwise specified, are commercially available. The following detailed description, in conjunction with embodiments, further illustrates this application: Raw material specifications: Tocotrienol (CAS No.: 25612-59-3), ethylene oxide (CAS No.: 75-21-8), graphene oxide purchased from CarbonFeng Technology, EDC 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (CAS No.: 25952-53-8), N-hydroxysuccinimide (CAS No.: 6066-82-6), citric acid (CAS No.: 77-92-9), acrylic acid (CAS No.: 79-10-7), acrylamide (CAS No.: 79-06-1), 2-acrylamido-2-methylpropanesulfonic acid (CAS No.: 15214-89-8), initiator ammonium persulfate (CAS No.: 7727-54-0), crosslinking agent N,N'-methylenebisacrylamide (CAS No.: 110-26-9), succinic anhydride (CAS No.: 25612-59-3), ethylene oxide (CAS No.: 75-21-8), graphene oxide purchased from CarbonFeng Technology, EDC 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (CAS No.: 25952-53-8), N-hydroxysuccinimide (CAS No.: 6066-82-6), citric acid (CAS No.: 77-92-9), ammonium persulfate (CAS No.: 7727-54-0), crosslinking agent N,N'-methylenebisacrylamide (CAS No.: 110-26-9), succinic anhydride (CAS No.: 25612-59-3), ethylene oxide (CAS No.: 75-21-8), graphene oxide (CAS No.: 75-21-8), ethylene oxide (CAS No.: The following materials were used: silane coupling agent KH-550 (CAS No.: 919-30-2), N,N-dimethylformamide (CAS No.: 68-12-2), chopped basalt fiber (purchased from Shandong Hongsheng New Material Co., Ltd.), polyvinyl alcohol fiber (purchased from Shandong Hongsheng New Material Co., Ltd.), polyacrylonitrile fiber (purchased from Tianyi Engineering Fiber), alkynyl polyethylene glycol acrylate (purchased from Carbon Water Technology), silicate cement PO42.5, mineral powder S95, fly ash grade I, medium sand fineness modulus 2.8, average particle size 0.3mm, crushed stone 5-20mm continuously graded granite crushed stone, methyl cellulose ether (CAS No.: 9004-67-5), polyoxyethylene ether (CAS No.: 9004-95-9), and early-strength high-efficiency water-reducing agent FDN-1 (purchased from Hefei Yongyuan Building Materials Co., Ltd.).

[0029] Example 1 Preparation of modified toughening and durability agents 9.6 kg of tocotrienol and 0.1 kg of sodium hydride were added to a high-pressure reactor. After sealing, stirring was started at 500 rpm. The reactor was evacuated and the air inside was replaced with nitrogen three times. After heating to 120°C, 10.3 kg of ethylene oxide was introduced over 2 hours, with the pressure controlled below 200 kPa. The reaction was carried out for 1 hour, and the product was discharged to obtain tocotrienol polyoxyethylene ether. 0.1 kg of graphene oxide, 0.1 kg of EDC, and 0.02 kg of N-hydroxysuccinimide were mixed and dispersed in 200 kg of N,N-dimethylformamide to obtain an activation solution. The activation solution was activated at 40°C for 2 hours. After centrifugation, the supernatant was removed to obtain activated graphene oxide. 9.97 kg of tocotrienol polyoxyethylene ether and 0.03 kg of activated graphene oxide were dispersed in deionized water and reacted at 500 rpm for 3 h in a water bath at 40 °C to obtain the product. The product was washed with deionized water and ethanol and then dried under vacuum at 40 °C to obtain graphene oxide-terminated polyoxyethylene ether.

[0030] 150 kg of fly ash and 0.5 kg of citric acid were dispersed in 200 L of deionized water to obtain a fly ash modification solution. The solution was stirred at 500 rpm for 2 h in a 60 °C water bath. The filtered solid was dried in an 80 °C oven for 6 h to obtain modified fly ash. 6 kg of graphene oxide-terminated polyoxyethylene ether, 9 kg of composite monomer, and 135 kg of fly ash were mixed in a mixing vessel. The mass ratio of acrylic acid, acrylamide, and 2-acrylamide-2-methylpropanesulfonic acid in the composite monomer was 1:7.5:4. 0.75 kg of initiator, 1.5 kg of crosslinking agent, and 70 kg of deionized water were added to the mixing vessel. The temperature in the mixing vessel was controlled at 40 °C, and the mixture was stirred at 200 rpm for 10 min. The crude product was obtained by filtration. The crude product was washed with deionized water and ethanol, and then vacuum dried at 40 °C to obtain a modified toughening and durability agent.

[0031] Preparation of composite modified fibers 0.01 kg of succinic anhydride and 0.022 kg of silane coupling agent were mixed and dispersed in 1 L of N,N-dimethylformamide. The mixture was stirred at 200 rpm for 3 h in an 80 °C water bath to obtain a modified solution. 1 kg of nano-alumina was dispersed in 20 L of N,N-dimethylformamide and ultrasonically dispersed for 0.5 h. Then, 20 L of deionized water was added to obtain an alumina dispersion. The alumina dispersion was added to the modified solution and stirred at 500 rpm for 3 h in a 40 °C water bath. The precipitate obtained by centrifugation was washed with deionized water and dried in an 80 °C oven for 6 h to obtain silane-modified nano-alumina.

[0032] 47.26 kg of composite fiber and 0.38 kg of silane-modified nano-alumina were mixed and dispersed in 100 L of a solution containing ethanol and deionized water at a mass ratio of 4:1 to obtain a suspension. The mass ratio of short-cut basalt fiber, polyvinyl alcohol fiber and polyacrylonitrile fiber in the composite fiber was 2:0.5:1.5. After ultrasonic oscillation for 30 min, 2.36 kg of alkynyl polyethylene glycol acrylate was added to the suspension. The mixture was stirred at 500 rpm for 2 h in a 60 °C water bath. After filtration, a mixed product was obtained. The mixed product was dried in an oven at 80 °C for 8 h to obtain the composite modified fiber.

[0033] Preparation of C70 high-performance concrete 300 kg of cement, 100 kg of mineral powder, 80 kg of modified toughening and durability agent and 120 kg of water are mixed evenly to obtain cement premix; 500 kg of medium sand, 800 kg of crushed stone, 3 kg of methyl cellulose ether and 30 kg of composite modified fiber are mixed and dispersed into cement premix to obtain concrete mix; after pouring the concrete mix, it is cured to obtain C70 high performance concrete.

[0034] Example 2 Preparation of modified toughening and durability agents 9.6 kg of tocotrienol and 0.1 kg of sodium hydride were added to a high-pressure reactor. After sealing, stirring was started at 500 rpm. The reactor was evacuated and the air inside was replaced with nitrogen three times. After heating to 120°C, 10.3 kg of ethylene oxide was introduced over 2 hours, with the pressure controlled below 200 kPa. The reaction was carried out for 1 hour, and the product was discharged to obtain tocotrienol polyoxyethylene ether. 0.1 kg of graphene oxide, 0.1 kg of EDC, and 0.02 kg of N-hydroxysuccinimide were mixed and dispersed in 200 kg of N,N-dimethylformamide to obtain an activation solution. The activation solution was activated at 40°C for 2 hours. After centrifugation, the supernatant was removed to obtain activated graphene oxide. 9.95 kg of tocotrienol polyoxyethylene ether and 0.05 kg of activated graphene oxide were dispersed in deionized water and reacted at 500 rpm for 3 h in a water bath at 40 °C to obtain the product. The product was washed with deionized water and ethanol and then dried under vacuum at 40 °C to obtain graphene oxide-terminated polyoxyethylene ether.

[0035] 150 kg of fly ash and 0.5 kg of citric acid were dispersed in 200 L of deionized water to obtain a fly ash modification solution. The solution was stirred at 500 rpm for 2 h in a 60 °C water bath. The filtered solid was dried in an 80 °C oven for 6 h to obtain modified fly ash. 6 kg of graphene oxide-terminated polyoxyethylene ether, 9 kg of composite monomer, and 135 kg of fly ash were mixed in a mixing vessel. The mass ratio of acrylic acid, acrylamide, and 2-acrylamide-2-methylpropanesulfonic acid in the composite monomer was 1:7.5:4. 0.75 kg of initiator, 1.5 kg of crosslinking agent, and 70 kg of deionized water were added to the mixing vessel. The temperature in the mixing vessel was controlled at 40 °C, and the mixture was stirred at 200 rpm for 10 min. The crude product was obtained by filtration. The crude product was washed with deionized water and ethanol, and then vacuum dried at 40 °C to obtain a modified toughening and durability agent.

[0036] Preparation of composite modified fibers 0.01 kg of succinic anhydride and 0.022 kg of silane coupling agent were mixed and dispersed in 1 L of N,N-dimethylformamide. The mixture was stirred at 200 rpm for 3 h in an 80 °C water bath to obtain a modified solution. 1 kg of nano-alumina was dispersed in 20 L of N,N-dimethylformamide and ultrasonically dispersed for 0.5 h. Then, 20 L of deionized water was added to obtain an alumina dispersion. The alumina dispersion was added to the modified solution and stirred at 500 rpm for 3 h in a 40 °C water bath. The precipitate obtained by centrifugation was washed with deionized water and dried in an 80 °C oven for 6 h to obtain silane-modified nano-alumina.

[0037] 46.9 kg of composite fiber and 0.75 kg of silane-modified nano-alumina were mixed and dispersed in 100 L of a solution containing ethanol and deionized water at a mass ratio of 4:1 to obtain a suspension. The mass ratio of short-cut basalt fiber, polyvinyl alcohol fiber and polyacrylonitrile fiber in the composite fiber was 2:0.5:1.5. After ultrasonic oscillation for 30 min, 2.35 kg of alkynyl polyethylene glycol acrylate was added to the suspension. The mixture was stirred at 500 rpm for 2 h in a 60 °C water bath. After filtration, a mixed product was obtained. The mixed product was dried in an oven at 80 °C for 8 h to obtain the composite modified fiber.

[0038] Preparation of C70 high-performance concrete 400 kg of cement, 120 kg of mineral powder, 120 kg of modified toughening and durability agent and 150 kg of water are mixed evenly to obtain cement premix; 600 kg of medium sand, 900 kg of crushed stone, 5 kg of methyl cellulose ether and 40 kg of composite modified fiber are mixed and dispersed into cement premix to obtain concrete mix; after pouring the concrete mix, it is cured to obtain C70 high performance concrete.

[0039] Example 3 Preparation of modified toughening and durability agents 9.6 kg of tocotrienol and 0.1 kg of sodium hydride were added to a high-pressure reactor. After sealing, stirring was started at 500 rpm. The reactor was evacuated and the air inside was replaced with nitrogen three times. After heating to 120°C, 10.3 kg of ethylene oxide was introduced over 2 hours, with the pressure controlled below 200 kPa. The reaction was carried out for 1 hour, and the product was discharged to obtain tocotrienol polyoxyethylene ether. 0.1 kg of graphene oxide, 0.1 kg of EDC, and 0.02 kg of N-hydroxysuccinimide were mixed and dispersed in 200 kg of N,N-dimethylformamide to obtain an activation solution. The activation solution was activated at 40°C for 2 hours. After centrifugation, the supernatant was removed to obtain activated graphene oxide. 9.96 kg of tocotrienol polyoxyethylene ether and 0.04 kg of activated graphene oxide were dispersed in deionized water and reacted at 500 rpm for 3 h in a water bath at 40 °C to obtain the product. The product was washed with deionized water and ethanol and then dried under vacuum at 40 °C to obtain graphene oxide-terminated polyoxyethylene ether.

[0040] 150 kg of fly ash and 0.5 kg of citric acid were dispersed in 200 L of deionized water to obtain a fly ash modification solution. The solution was stirred at 500 rpm for 2 h in a 60 °C water bath. The filtered solid was dried in an 80 °C oven for 6 h to obtain modified fly ash. 6 kg of graphene oxide-terminated polyoxyethylene ether, 9 kg of composite monomer, and 135 kg of fly ash were mixed in a mixing vessel. The mass ratio of acrylic acid, acrylamide, and 2-acrylamide-2-methylpropanesulfonic acid in the composite monomer was 1:7.5:4. 0.75 kg of initiator, 1.5 kg of crosslinking agent, and 70 kg of deionized water were added to the mixing vessel. The temperature in the mixing vessel was controlled at 40 °C, and the mixture was stirred at 200 rpm for 10 min. The crude product was obtained by filtration. The crude product was washed with deionized water and ethanol, and then vacuum dried at 40 °C to obtain a modified toughening and durability agent.

[0041] Preparation of composite modified fibers 0.01 kg of succinic anhydride and 0.022 kg of silane coupling agent were mixed and dispersed in 1 L of N,N-dimethylformamide. The mixture was stirred at 200 rpm for 3 h in an 80 °C water bath to obtain a modified solution. 1 kg of nano-alumina was dispersed in 20 L of N,N-dimethylformamide and ultrasonically dispersed for 0.5 h. Then, 20 L of deionized water was added to obtain an alumina dispersion. The alumina dispersion was added to the modified solution and stirred at 500 rpm for 3 h in a 40 °C water bath. The precipitate obtained by centrifugation was washed with deionized water and dried in an 80 °C oven for 6 h to obtain silane-modified nano-alumina.

[0042] 47.08 kg of composite fiber and 0.56 kg of silane-modified nano-alumina were mixed and dispersed in 100 L of a solution containing ethanol and deionized water at a mass ratio of 4:1 to obtain a suspension. The mass ratio of short-cut basalt fiber, polyvinyl alcohol fiber and polyacrylonitrile fiber in the composite fiber was 2:0.5:1.5. After ultrasonic oscillation for 30 min, 2.36 kg of alkynyl polyethylene glycol acrylate was added to the suspension. The mixture was stirred at 500 rpm for 2 h in a 60 °C water bath. After filtration, a mixed product was obtained. The mixed product was dried in an 80 °C oven for 8 h to obtain the composite modified fiber.

[0043] Preparation of C70 high-performance concrete 350 kg of cement, 110 kg of mineral powder, 100 kg of modified toughening and durability agent, and 135 kg of water are mixed evenly to obtain a cement premix; 550 kg of medium sand, 850 kg of crushed stone, 4 kg of methyl cellulose ether, and 35 kg of composite modified fiber are mixed and dispersed into the cement premix to obtain a concrete mix; the concrete mix is ​​poured and cured to obtain C70 high-performance concrete.

[0044] Example 4 Example 4 is based on Example 3. The only difference between Example 4 and Example 3 is that in Example 4, the amount of tocotrienol polyoxyethylene ether used in the preparation of the modified toughening and durability agent is 9.99 kg and the amount of activated graphene oxide used is 0.01 kg.

[0045] Example 5 Example 5 is based on Example 3. The only difference between Example 5 and Example 3 is that in Example 5, the amount of tocotrienol polyoxyethylene ether used in preparing the modified toughening and durability agent is 9.93 kg and the amount of activated graphene oxide used is 0.07 kg.

[0046] Example 6 Example 6 is based on Example 3. The only difference between Example 6 and Example 3 is that in Example 6, the tocotrienol polyoxyethylene ether used in the preparation of the modified toughening and durability agent is replaced with polyoxyethylene ether.

[0047] Example 7 Example 7 is based on Example 3. The only difference between Example 7 and Example 3 is that in Example 7, the activated graphene oxide used in the preparation of the modified toughening and durability agent is replaced with graphene oxide.

[0048] Example 8 Example 8 is based on Example 3. The only difference between Example 8 and Example 3 is that in Example 8, graphene oxide-terminated polyoxyethylene ether is replaced with polyoxyethylene ether.

[0049] Example 9 Example 9 is based on Example 3. The only difference between Example 9 and Example 3 is that 2-acrylamide-2-methylpropanesulfonic acid is not added when preparing the modified toughening and durable agent in Example 9.

[0050] Example 10 Example 10 is based on Example 3. The only difference between Example 10 and Example 3 is that in Example 10, modified fly ash is replaced with fly ash when preparing the modified toughening and durability agent.

[0051] Example 11 Example 11 is based on Example 3. The only difference between Example 11 and Example 3 is that in Example 11, the silane-modified nano-alumina used in the preparation of composite fibers is replaced with nano-alumina.

[0052] Example 12 Example 12 is based on Example 3. The only difference between Example 12 and Example 3 is that in Example 12, alkynyl polyethylene glycol acrylate is not added when preparing the composite fiber, and the balance is made up with composite fiber.

[0053] Example 13 Example 13 is based on Example 3. The only difference between Example 13 and Example 3 is that in Example 13, the composite fiber is replaced with short-cut basalt fiber when preparing the composite fiber.

[0054] Example 14 Example 14 is based on Example 3. The only difference between Example 14 and Example 3 is that in Example 14, the composite fiber is replaced with short-cut basalt fiber and polyvinyl alcohol fiber when preparing the composite fiber.

[0055] Example 15 Example 15 is based on Example 3. The only difference between Example 15 and Example 3 is that in Example 15, the amount of composite fiber is 47.44 kg, the amount of silane-modified nano-alumina is 0.19 kg, and the amount of alkynyl polyethylene glycol acrylate is 2.37 kg.

[0056] Example 16 Example 16 is based on Example 3. The only difference between Example 16 and Example 3 is that in Example 16, the amount of composite fiber is 46.73 kg, the amount of silane-modified nano-alumina is 0.93 kg, and the amount of alkynyl polyethylene glycol acrylate is 2.34 kg.

[0057] Comparative Example 1 Comparative Example 1 is based on Example 3. The only difference between Comparative Example 1 and Example 3 is that the modified toughening and durability agent in Comparative Example 1 is replaced with the early strength high-efficiency water-reducing agent FDN-1.

[0058] Comparative Example 2 Comparative Example 2 is based on Example 3. The only difference between Comparative Example 2 and Example 3 is that the composite fiber in Comparative Example 2 is replaced with polyacrylonitrile fiber.

[0059] Performance testing The standard GB / T50081-2016 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" was selected as the standard. Cube specimens with a side length of 150 mm were prepared as test samples. After curing, the 7-day and 28-day compressive strength and 28-day splitting tensile strength of the specimens were tested. After 28 days of curing, the number of cracks per unit area and the crack area were measured. Three samples were prepared for each specimen, and the average value was taken after measurement. The results were recorded in Table 1.

[0060] Table 1. Test results of compressive strength, splitting tensile strength and crack resistance of C70 high-performance concrete. As shown in Table 1, the 7-day compressive strength of Examples 1-3 is greater than 74.5 MPa, the 28-day compressive strength is greater than 86.7 MPa, the 28-day tensile strength is greater than 9.1 MPa, and the number of cracks is less than 5.2 per m. 2 The cracked area is less than 88mm 2 / m 2 This demonstrates that the C70 high-performance concrete prepared in this application has good durability, compressive strength, and tensile strength.

[0061] As shown in Table 1, the only difference between Examples 4 and 5 and Example 3 is that the mass ratio of tocotrienol polyoxyethylene ether to activated graphene oxide in Example 4 is 1:0.001, and the mass ratio of tocotrienol polyoxyethylene ether to activated graphene oxide in Example 5 is 1:0.007. Compared with Example 3, the durability, compressive strength, and tensile strength of concrete in Examples 4 and 5 are all reduced. This is because the mass ratio of tocotrienol polyoxyethylene ether to activated graphene oxide is not within the specified range. Too much or too little activated graphene oxide will affect the dispersion and reactivity of graphene oxide-terminated polyoxyethylene ether, and thus affect the strength and stability of the polymer network formed by the modified toughening and durability agent, thereby reducing the durability, compressive strength, and tensile strength of concrete.

[0062] As shown in Table 1, the differences between Examples 6, 7, 8, 9, and 10 and Example 3 are only as follows: In Example 6, the tocotrienol polyoxyethylene ether used in preparing the modified toughening and durability agent was replaced with polyoxyethylene ether; in Example 7, the activated graphene oxide used in preparing the modified toughening and durability agent was replaced with graphene oxide; in Example 8, the graphene oxide-terminated polyoxyethylene ether was replaced with polyoxyethylene ether; in Example 9, 2-acrylamide-2-methylpropanesulfonic acid was not added when preparing the modified toughening and durability agent; and in Example 10, the modified fly ash was replaced with fly ash. Compared with Example 3, the durability, compressive strength, and tensile strength of concrete in Examples 6, 7, 8, 9, and 10 all decreased. This is because of the changes in the synthesis of the modified toughening and durability agent. The components were replaced. When polyoxyethylene ether lacks the tocotrienol structure, the ability of the modified toughening and durability agent to regulate the hydration of concrete is weakened. When graphene oxide lacks activation, the end-capping reaction is difficult to occur, the dispersibility of graphene oxide decreases, and the synergistic effect with modified fly ash is weakened. When both tocotrienol and graphene oxide are lacking, the performance is further weakened. Without the addition of 2-acrylamide-2-methylpropanesulfonic acid, the synergistic effect of the components in the polymer network is weakened. When modified fly ash is replaced with fly ash, the dispersibility of fly ash decreases, and it will agglomerate in the polymer network, affecting the toughness and strength of the polymer network, reducing the gain effect on concrete, and thus reducing the durability, compressive strength and tensile strength of concrete.

[0063] As shown in Table 1, the differences between Examples 11, 12, 13, and 14 and Example 3 are only as follows: In Example 11, the silane-modified nano-alumina used in preparing the composite fiber was replaced with nano-alumina; in Example 12, no alkynyl polyethylene glycol acrylate was added during the preparation of the composite fiber, and the remainder was made up with composite fiber; in Example 13, the composite fiber was replaced with chopped basalt fiber; and in Example 14, the composite fiber was replaced with chopped basalt fiber and polyvinyl alcohol fiber. Compared with Example 3, Examples 11, 12, 13, and 14 show improved concrete durability. Durability, compressive strength, and tensile strength all decreased. This is because the components used to prepare the composite modified fibers were changed. The nano-alumina lacked modification treatment with acid anhydride and silane coupling agent, resulting in decreased dispersibility and weakened bonding performance with the fibers. Without the addition of alkynyl polyethylene glycol acrylate, the dispersibility of the composite modified fibers decreased, the number of active sites decreased, and the synergistic effect with the polymer network decreased. Replacing the components of the compounded fibers would destroy the synergistic effect between the fibers, and the synergistic effect between the fiber network and the polymer network would decrease, thus reducing the durability, compressive strength, and tensile strength of the concrete.

[0064] As shown in Table 1, the only difference between Examples 15 and 16 and Example 3 is that the mass ratio of composite fiber, silanized nano-alumina, and alkynyl polyethylene glycol acrylate in Example 15 is 1:0.004:0.05, while the mass ratio in Example 16 is 1:0.02:0.05. Compared with Example 3, the durability, compressive strength, and tensile strength of concrete in Examples 15 and 16 are all reduced. This is because the mass ratio of composite fiber, silanized nano-alumina, and alkynyl polyethylene glycol acrylate is not within the specified range. Too much or too little silanized nano-alumina will affect the dispersibility of the composite modified fiber and its connection performance with the polymer network, thereby affecting the synergistic effect between the two, resulting in a decrease in the durability, compressive strength, and tensile strength of the concrete.

[0065] As shown in Table 1, the only difference between Comparative Example 1 and Example 3 is that the modified toughening and durability agent in Comparative Example 1 was replaced with the early-strength high-efficiency water-reducing agent FDN-1. Compared with Example 3, the durability, compressive strength, and tensile strength of the concrete in Comparative Example 1 all decreased significantly. This is because replacing the modified toughening and durability agent with the early-strength high-efficiency water-reducing agent FDN-1 lacks the toughening modification of graphene oxide and modified fly ash, and also lacks the polymer network structure. This reduces the toughening effect on the concrete and weakens the regulation of the hydration reaction, thus significantly reducing the durability, compressive strength, and tensile strength of the concrete.

[0066] As shown in Table 1, the only difference between Comparative Example 2 and Example 3 is that the composite fiber in Comparative Example 2 was replaced with polyacrylonitrile fiber. Compared with Example 3, the durability, compressive strength, and tensile strength of the concrete in Comparative Example 2 all decreased significantly. This is because replacing the composite modified fiber with polyacrylonitrile fiber lacks the compounding effect between fibers and the modification treatment of silane-modified nano-alumina and alkynyl polyethylene glycol acrylate, resulting in decreased reactivity and compatibility. At the same time, the synergistic effect of the cellulose network and polymer network is weakened, thus the durability, compressive strength, and tensile strength of the concrete all decreased significantly.

[0067] This specific embodiment is merely an explanation of this application and is not intended to limit it. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification but must be determined according to the scope of the claims.

Claims

1. A C70 high performance concrete, characterized by: The components include the following parts by mass: 300-400 parts cement 100-120 parts of mineral powder 500-600 portions of medium sand 800-900 pieces of crushed stone 3-5 parts of methylcellulose ether Modified toughening and durability agent 80-120 parts 30-40 parts of composite modified fiber 120-150 parts water; The raw materials for preparing the modified toughening and durability agent include graphene oxide-terminated polyoxyethylene ether, composite monomers, and modified fly ash; the graphene oxide-terminated polyoxyethylene ether reacts with the composite monomers and modified fly ash to form a cross-linked network; The raw materials for preparing the graphene oxide-terminated polyoxyethylene ether include tocotrienol polyoxyethylene ether and activated graphene oxide. The raw materials for preparing the tocotrienol polyoxyethylene ether include tocotrienol and ethylene oxide; The mass ratio of the tocotrienol polyoxyethylene ether to the activated graphene oxide is 1:(0.003-0.005). The composite monomers include acrylic acid, acrylamide, and 2-acrylamide-2-methylpropanesulfonic acid; The raw materials for preparing the composite modified fiber include composite fiber, silane-modified nano-alumina, and alkynyl polyethylene glycol acrylate. The composite fiber includes chopped basalt fiber, polyvinyl alcohol fiber, and polyacrylonitrile fiber; The mass ratio of the composite fiber, silanized nano-alumina, and alkynyl polyethylene glycol acrylate is 1:(0.008-0.016):0.05; The composite modified fiber is prepared by the following steps: the composite fiber and silane-modified nano-alumina are mixed and dispersed in a solution of ethanol and deionized water at a mass ratio of 4:1 to obtain a suspension. After ultrasonic oscillation, alkynyl polyethylene glycol acrylate is added to the suspension and stirred at 500 rpm for 2 hours under a water bath at 60°C. After filtration, a mixed product is obtained and dried in an oven at 80°C to obtain the composite modified fiber.

2. The C70 high performance concrete according to claim 1, characterized in that: The C70 high-performance concrete is prepared using the following steps: Cement, mineral powder, modified toughening and durability agent and water are mixed evenly to obtain cement premix; Medium sand, crushed stone, methyl cellulose ether and composite modified fiber are mixed and dispersed into cement premix to obtain concrete mix; After the concrete mix is ​​poured and cured, C70 high-performance concrete is obtained.

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