High-performance aging-resistant concrete and preparation method thereof

Abstract

The application discloses high-performance anti-aging concrete and a preparation method thereof, and belongs to the technical field of concrete materials, and comprises the following raw materials in parts by weight: cement 500-700 parts, modified fiber 50-70 parts, fly ash 110-160 parts, sand 600-800 parts, gravel 900-1100 parts, defoaming agent 5-10 parts, water reducing agent 10-20 parts, modified asphalt 40-60 parts and water 250-350 parts. The high-performance anti-aging concrete has the advantages that the modified asphalt and the modified fiber are added, the two together strengthen the interface of hardened concrete, greatly improve the mechanical properties of the concrete, and the 2-hydroxy-4-n-octyloxybenzophenone light absorber is introduced into the modified asphalt and the gamma-glycidoxypropyltrimethoxysilane adhesive is added into the modified fiber, so that the anti-aging performance and the anti-pulverization performance of the concrete outdoors are improved, and the high-performance anti-aging concrete has a good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of concrete materials technology, specifically relating to a high-performance aging-resistant concrete and its preparation method. Background Technology

[0002] In modern architecture, concrete is the most widely used and consumed structural material. Because of its ease of molding, convenient transportation, high plasticity, and high strength, concrete is widely used in building and foundation construction. As the most widely used building material, concrete plays an irreplaceable role and function in modern construction, water conservancy, ports, highways, and bridges.

[0003] With the continuous development of concrete constituent materials, people's performance requirements for concrete are no longer limited to compressive strength. Instead, based on strength alone, greater emphasis is placed on the balance and coordination of comprehensive indicators such as durability, deformation performance, fire and explosion resistance, water resistance, toughness, corrosion resistance, thermal insulation, health and environmental protection, and cost reduction. The requirements for various concrete performance indicators are more explicit, detailed, and specific than before. Simultaneously, improvements in construction equipment and the continuous emergence and promotion of new construction techniques have enabled concrete technology to adapt to different design, construction, and usage requirements, resulting in rapid development.

[0004] Chinese patent application number 201610801767.3 discloses a method for preparing fiber-reinforced high-damping polymer concrete. The concrete in this method comprises cement, water, fly ash, sand, crushed stone, polymer emulsion, high-efficiency water-reducing agent, defoamer, dispersant, and PVA fiber. The aforementioned patent uses a dispersant to increase the dispersibility of the polymer emulsion in cement-based concrete. However, because the polymer emulsion and cement-based cementitious materials easily compete for active silica in cementitious silicates, incomplete cement hydration and cement particle aggregation occur, leading to voids in the concrete, poor concrete hardness, and poor waterproofing performance.

[0005] Therefore, researching and developing a type of concrete with high strength and aging resistance is of great importance for delaying concrete corrosion and extending its service life. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a high-performance aging-resistant concrete and its preparation method. This concrete has good density, strong crack resistance and impact resistance, prevents cracking, and is not prone to pulverization under long-term use, thus exhibiting good durability.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A high-performance, aging-resistant concrete, by weight, comprises the following raw materials: 500-700 parts cement, 50-70 parts modified fiber, 110-160 parts fly ash, 600-800 parts sand, 900-1100 parts crushed stone, 5-10 parts defoamer, 10-20 parts water-reducing agent, 100-150 parts modified asphalt, and 250-350 parts water.

[0009] Preferably, the cement is one or more of 42.5 ordinary Portland cement, 52.5 ordinary Portland cement, and 42.5 rapid-hardening sulfoaluminate cement; the fineness modulus of the sand is 1.6-2.2, and the average particle size is 0.15-0.25 mm; the particle size of the crushed stone is 6-10 mm.

[0010] Preferably, the defoamer is one or more of polyether defoamers, silicone defoamers, and polyether-modified polysiloxane defoamers; the water-reducing agent is one of sodium methylene dinaphthalene sulfonate and polycarboxylate water-reducing agents.

[0011] Preferably, the method for preparing the modified fiber includes the following steps:

[0012] (a) Glass fiber and lignin fiber are mixed evenly, and then impregnated in sodium hydroxide solution. After impregnation, the mixture is filtered, washed and dried to obtain pretreated fiber.

[0013] (b) The pretreated fiber obtained in step (a) was added to anhydrous ethanol, followed by the addition of aminopropyltriethoxysilane and trihexyltetradecylphosphine chloride. The mixture was stirred and reacted. After the reaction was completed, the mixture was filtered, washed and dried to obtain the mixed fiber.

[0014] (c) Add γ-glycidyl etheroxypropyltrimethoxysilane to anhydrous ethanol and stir until homogeneous. Then add polyester fiber and the mixed fiber obtained in step (b), and ball mill. After ball milling, dry to obtain the modified fiber.

[0015] Preferably, in step (a), the mass ratio of glass fiber to lignin fiber is 1:1-3; the mass concentration of the sodium hydroxide solution is 4-8%, and the impregnation time is 5-10 h; in step (b), the mass ratio of the pretreated fiber, aminopropyltriethoxysilane, and trihexyltetradecylphosphine chloride is 100:3-6:5-10; and the stirring reaction temperature is 50-80℃, and the reaction time is 3-5 h.

[0016] Preferably, in step (c), the mass ratio of polyester fiber, γ-glycidyl etheroxypropyltrimethoxysilane, and mixed fiber is 20-30:2-5:40-60; the ball milling speed is 1000-2000 r / min, and the ball milling time is 1-2 h.

[0017] Preferably, the method for preparing the modified asphalt includes the following steps:

[0018] S1. Add hydrotalcite to distilled water and stir at room temperature for 1-3 hours. Then add octadecyltrimethylammonium chloride and reflux at 60-80°C for 2-4 hours. After the reaction is complete, filter, wash and dry to obtain a solid product. Then add the obtained solid product to anhydrous ethanol, followed by cellulose ether and 2-hydroxy-4-n-octyloxybenzophenone. Stir and react. After the reaction is complete, rotary evaporate to obtain modified hydrotalcite.

[0019] S2. Add octylphenol polyoxyethylene ether to water and stir evenly. Then add sodium fatty alcohol polyoxyethylene ether sulfate and stir evenly. Adjust the pH value to 3-5 with hydrochloric acid to obtain a mixture. Heat petroleum asphalt to melt. Then, the modified hydrotalcite, mixture and SBS rubber powder obtained in step S1 are sheared and emulsified in a dispersion emulsifier to obtain modified asphalt.

[0020] Preferably, in step S1, the mass ratio of hydrotalcite to octadecyltrimethylammonium chloride is 100:3-5; the mass ratio of the solid product, cellulose ether, and 2-hydroxy-4-n-octyloxybenzophenone is 100:5-10:10-15; the stirring reaction temperature is 70-90℃, and the time is 3-5h; in step S2, the mass ratio of octylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether sodium sulfate, and water is 1-3:3-5:50-70; the mass ratio of asphalt, modified hydrotalcite, mixture, and SBS rubber powder is 100:10-20:30-50:5-10; the melting temperature is 160-180℃; and the shear emulsification reaction temperature is 160-180℃, and the emulsification time is 0.5-2h.

[0021] This invention also protects a method for preparing the aforementioned high-performance aging-resistant concrete, comprising the following steps:

[0022] (1) Weigh each raw material according to the formula, and mix cement, fly ash, sand and crushed stone to obtain a solid mixture;

[0023] (2) Add water, defoamer and water-reducing agent to the solid mixture obtained in step (1) and stir evenly to obtain a slurry mixture;

[0024] (3) Add the modified asphalt and modified fiber to the slurry mixture obtained in step (2), and stir to obtain the high-performance aging-resistant concrete.

[0025] Preferably, the stirring speed in step (2) is 200-300 r / min and the stirring time is 15-30 min; the stirring speed in step (3) is 300-400 r / min and the stirring time is 10-20 min.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The high-performance aging-resistant concrete prepared by this invention first modifies hydrotalcite by inserting octadecyltrimethylammonium chloride into the interlayer spaces of the hydrotalcite to increase the interlayer spacing. On the one hand, the uniformly dispersed hydrotalcite layers can extend the oxygen diffusion path, significantly increasing the anti-aging performance of the asphalt. On the other hand, it also facilitates the subsequent entry of 2-hydroxy-4-n-octyloxybenzophenone into the interlayer spaces of the hydrotalcite. Then, octylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether sodium sulfate are added to prepare an aqueous solution. The aqueous solution, 2-hydroxy-4-n-octyloxybenzophenone, modified hydrotalcite, SBS rubber powder and asphalt are blended and modified. - Octyloxybenzophenone has excellent UV resistance, which can greatly improve the outdoor aging performance of asphalt. At the same time, the addition of octylphenol polyoxyethylene ether organically modifies the surface and edges of the hydrotalcite flakes, thereby changing the inherent hydrophilic properties of hydrotalcite, improving the organic compatibility between hydrotalcite and asphalt, making it more tightly bonded to the asphalt, and the modified hydrotalcite is more evenly dispersed in the asphalt. In addition, sodium fatty alcohol polyoxyethylene ether sulfate can simultaneously emulsify the asphalt, and the addition of SBS toughens and modifies the asphalt, so that the asphalt undergoes an emulsification reaction during modification, resulting in higher stability. After the modified asphalt is added to the concrete formula, the mechanical strength and aging resistance of the concrete can be improved.

[0028] (2) The high-performance aging-resistant concrete provided by this invention incorporates polyester fibers with advantages such as soft texture and high tensile strength of monofilaments. Adding these fibers to concrete can provide excellent reinforcement, improve the interlocking ability within the concrete, inhibit the generation and development of microcracks, and enhance the low-temperature crack resistance of the concrete. Through blending modification of glass fibers and lignin fibers, they are first alkaline activated to increase the porosity of the lignin and the activity of its surface hydroxyl groups. Subsequently, trihexyltetradecylphosphine chloride and aminopropyltriethoxysilane are added, allowing the aminopropyltriethoxysilane to react with the glass fibers. Siloxanes are grafted onto the surfaces of fibers and lignin fibers, while trihexyltetradecylphosphine chloride is used as a surfactant to make the fibers more evenly dispersed in concrete. This overcomes the problem of fibers easily clumping together during the mixing process with concrete, which leads to inconsistent strength in different parts of the concrete and reduces the overall strength of the concrete. Finally, polyester fibers and γ-glycidoxypropyltrimethoxysilane are added and ball-milled to adhere the lignin fibers and glass fibers to the surface of the polyester fibers. Under the action of silane, the modified fibers are not easy to fall off, reducing the phenomenon of concrete pulverization.

[0029] (3) The high-performance aging-resistant concrete provided by the present invention strengthens the interface of the hardened concrete by adding modified asphalt and modified fiber, which greatly improves the mechanical properties of the concrete. At the same time, the 2-hydroxy-4-n-octyloxybenzophenone light absorber introduced into the modified asphalt and the γ-glycidyl etheroxypropyltrimethoxysilane binder added into the modified fiber improve the outdoor aging resistance and powdering resistance of the concrete, and has good application prospects. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0031] The fly ash was purchased from Shijiazhuang Yuanjing Mineral Products Co., Ltd., and its mesh size was 325 mesh.

[0032] The polyether defoamer was purchased from Shandong Juneng Chemical Co., Ltd., and its brand name is JN-306.

[0033] The silicone defoamer was purchased from Sichuan Wanbang Qingyuan Environmental Technology Co., Ltd., and its brand name is WB521.

[0034] The polyether-modified polysiloxane defoamer was purchased from Dongguan Defeng Defoamer Co., Ltd., and its brand name is DF-2684.

[0035] The polycarboxylate superplasticizer was purchased from Liaoning Kelong Fine Chemical Co., Ltd., and its brand name is SP409.

[0036] The sodium methylene dinaphthalene sulfonate was purchased from Shandong Xiangzhao New Material Co., Ltd.

[0037] The petroleum asphalt is 90# petroleum asphalt;

[0038] The glass fiber was purchased from Taian Senyang Composite Materials Co., Ltd., with a fiber diameter of 9-13μm and a length of 3mm;

[0039] The lignin fibers were purchased from Taian Haoda New Materials Co., Ltd., with a diameter of 15-20 μm and a length of 3 mm;

[0040] The polyester fiber was purchased from Taian Senyang Composite Materials Co., Ltd., with a fiber diameter of 10-25μm and a length of 12mm;

[0041] The hydrotalcite was purchased from Jinan Zian Chemical Co., Ltd., and the particle size was 5-20μm.

[0042] The cellulose ether was purchased from Mitsui Chemicals (Shandong) Co., Ltd., and is hydroxyethyl cellulose ether.

[0043] The sodium fatty alcohol polyoxyethylene ether sulfate was purchased from Shandong Chuangying Chemical Co., Ltd.

[0044] The octylphenol polyoxyethylene ether was purchased from Jinan Jingbang New Materials Co., Ltd., and its product name is OP-10.

[0045] Example 1

[0046] A method for preparing high-performance aging-resistant concrete includes the following steps:

[0047] (1) Weigh each raw material according to the formula, and mix 60kg of 42.5 rapid hardening sulfoaluminate cement, 13kg of fly ash, 70kg of sand and 100kg of crushed stone to obtain a solid mixture;

[0048] (2) Add 30 kg of water, 0.8 kg of polyether modified polysiloxane defoamer and 1.5 kg of polycarboxylate water-reducing agent to the solid mixture obtained in step (1), and stir at 250 r / min for 25 min to obtain a slurry mixture;

[0049] (3) Add 13 kg of modified asphalt and 6 kg of modified fiber to the slurry mixture obtained in step (2), and stir for 15 min at a speed of 350 r / min to obtain the high-performance aging-resistant concrete.

[0050] The fineness modulus of the sand is 1.6-2.2, and the average particle size is 0.15-0.25 mm; the particle size of the crushed stone is 6-10 mm.

[0051] The method for preparing modified fibers includes the following steps:

[0052] (a) Mix 100g of glass fiber and 200g of lignin fiber evenly, then add 800mL of sodium hydroxide solution with a mass concentration of 6% and soak for 8h. After soaking, filter, wash and dry to obtain pretreated fiber.

[0053] (b) Add the pretreated fiber (100g) obtained in step (a) to 600mL of anhydrous ethanol, then add 5g of aminopropyltriethoxysilane and 8g of trihexyltetradecylphosphine chloride, stir at 70°C for 4h, filter, wash and dry after the reaction is complete to obtain mixed fiber;

[0054] (c) Add 4g of γ-glycidoxypropyltrimethoxysilane to 40mL of anhydrous ethanol and stir until homogeneous. Then add 25g of polyester fiber and 50g of the mixed fiber obtained in step (b). Ball mill at 1500r / min for 1.5h. After ball milling, dry to obtain the modified fiber.

[0055] The method for preparing the modified asphalt includes the following steps:

[0056] S1. 100g of hydrotalcite was added to 800mL of distilled water and stirred at room temperature for 2h. Then 4g of octadecyltrimethylammonium chloride was added and refluxed at 70℃ for 3h. After the reaction was completed, the product was filtered, washed and dried to obtain a solid product. Then 100g of the obtained solid product was added to 700mL of anhydrous ethanol, followed by 8g of cellulose ether and 13g of 2-hydroxy-4-n-octyloxybenzophenone. The product was stirred at 80℃ for 4h. After the reaction was completed, the ethanol was removed by rotary evaporation to obtain modified hydrotalcite.

[0057] S2. Add 2g of octylphenol polyoxyethylene ether to 100mL of water and stir until homogeneous. Then add 4g of fatty alcohol polyoxyethylene ether sodium sulfate and stir until homogeneous. Adjust the pH value to 4 with hydrochloric acid to obtain a mixture. Heat 100g of petroleum asphalt to 170℃ until melted. Then, add 15g of modified hydrotalcite, 40g of the mixture, and 8g of SBS rubber powder obtained in step S1 and perform a shear emulsification reaction in a dispersing emulsifier. The temperature of the shear emulsification reaction is 170℃ and the emulsification time is 1h to obtain modified asphalt.

[0058] Example 2

[0059] A method for preparing high-performance aging-resistant concrete includes the following steps:

[0060] (1) Weigh each raw material according to the formula, and mix 50kg of 42.5 ordinary Portland cement, 11kg of fly ash, 60kg of sand and 90kg of crushed stone to obtain a solid mixture;

[0061] (2) Add 25kg of water, 0.5kg of organosilicon defoamer and 1kg of sodium methylene dinaphthalene sulfonate to the solid mixture obtained in step (1), and stir at 200r / min for 15min to obtain a slurry mixture;

[0062] (3) Add 10 kg of modified asphalt and 5 kg of modified fiber to the slurry mixture obtained in step (2), and stir for 10 min at a speed of 300 r / min to obtain the high-performance aging-resistant concrete.

[0063] The fineness modulus of the sand is 1.6-2.2, and the average particle size is 0.15-0.25 mm; the particle size of the crushed stone is 6-10 mm.

[0064] The method for preparing modified fibers includes the following steps:

[0065] (a) Mix 100g of glass fiber and 100g of lignin fiber evenly, then add 800mL of sodium hydroxide solution with a mass concentration of 4% and soak for 5h. After soaking, filter, wash and dry to obtain pretreated fiber.

[0066] (b) Add the pretreated fiber (100g) obtained in step (a) to 600mL of anhydrous ethanol, then add 3g of aminopropyltriethoxysilane and 5g of trihexyltetradecylphosphine chloride, stir at 50°C for 3h, filter, wash and dry after the reaction is complete to obtain mixed fiber;

[0067] (c) Add 2g of γ-glycidoxypropyltrimethoxysilane to 40mL of anhydrous ethanol and stir until homogeneous. Then add 20g of polyester fiber and 40g of the mixed fiber obtained in step (b). Ball mill at 1000r / min for 1h. After ball milling, dry to obtain the modified fiber.

[0068] The method for preparing the modified asphalt includes the following steps:

[0069] S1. 100g of hydrotalcite was added to 800mL of distilled water and stirred at room temperature for 1h. Then, 3g of octadecyltrimethylammonium chloride was added and refluxed at 60℃ for 2h. After the reaction was completed, the product was filtered, washed and dried to obtain a solid product. Then, 100g of the obtained solid product was added to 700mL of anhydrous ethanol, followed by 5g of cellulose ether and 10g of 2-hydroxy-4-n-octyloxybenzophenone. The product was stirred at 70℃ for 3h. After the reaction was completed, the ethanol was removed by rotary evaporation to obtain modified hydrotalcite.

[0070] S2. Add 1g of octylphenol polyoxyethylene ether to 100mL of water and stir until homogeneous. Then add 3g of fatty alcohol polyoxyethylene ether sodium sulfate and stir until homogeneous. Adjust the pH value to 3 with hydrochloric acid to obtain a mixture. Heat 100g of petroleum asphalt to 160℃ until melted. Then, add 10g of modified hydrotalcite, 30g of the mixture, and 5g of SBS rubber powder obtained in step S1 and perform a shear emulsification reaction in a dispersing emulsifier. The temperature of the shear emulsification reaction is 160℃ and the emulsification time is 0.5h to obtain modified asphalt.

[0071] Example 3

[0072] A method for preparing high-performance aging-resistant concrete includes the following steps:

[0073] (1) Weigh each raw material according to the formula, and mix 70kg of 52.5 ordinary Portland cement, 16kg of fly ash, 80kg of sand and 110kg of crushed stone to obtain a solid mixture;

[0074] (2) Add 35kg water, 1kg polyether defoamer and 2kg sodium methylene dinaphthalene sulfonate to the solid mixture obtained in step (1), and stir at 300r / min for 30min to obtain a slurry mixture;

[0075] (3) Add 15 kg of modified asphalt and 7 kg of modified fiber to the slurry mixture obtained in step (2), and stir for 20 min at a speed of 400 r / min to obtain the high-performance aging-resistant concrete.

[0076] The fineness modulus of the sand is 1.6-2.2, and the average particle size is 0.15-0.25 mm; the particle size of the crushed stone is 6-10 mm.

[0077] The method for preparing modified fibers includes the following steps:

[0078] (a) Mix 100g of glass fiber and 300g of lignin fiber evenly, then add 800mL of sodium hydroxide solution with a mass concentration of 8% and soak for 10h. After soaking, filter, wash and dry to obtain pretreated fiber.

[0079] (b) Add the pretreated fiber (100g) obtained in step (a) to 600mL of anhydrous ethanol, then add 6g of aminopropyltriethoxysilane and 10g of trihexyltetradecylphosphine chloride, stir the reaction at 80°C for 5h, filter, wash and dry after the reaction is completed to obtain mixed fiber;

[0080] (c) Add 5g of γ-glycidyl oxypropyltrimethoxysilane to 40mL of anhydrous ethanol and stir until homogeneous. Then add 30g of polyester fiber and 60g of the mixed fiber obtained in step (b). Ball mill at 2000r / min for 2h. After ball milling, dry to obtain the modified fiber.

[0081] The method for preparing the modified asphalt includes the following steps:

[0082] S1. 100g of hydrotalcite was added to 800mL of distilled water and stirred at room temperature for 3h. Then 5g of octadecyltrimethylammonium chloride was added and refluxed at 80℃ for 4h. After the reaction was completed, the product was filtered, washed and dried to obtain a solid product. Then 100g of the obtained solid product was added to 700mL of anhydrous ethanol, followed by 10g of cellulose ether and 15g of 2-hydroxy-4-n-octyloxybenzophenone. The product was stirred at 90℃ for 5h. After the reaction was completed, the ethanol was removed by rotary evaporation to obtain modified hydrotalcite.

[0083] S2. Add 3g of octylphenol polyoxyethylene ether to 100mL of water and stir until homogeneous. Then add 5g of fatty alcohol polyoxyethylene ether sodium sulfate and stir until homogeneous. Adjust the pH value to 5 with hydrochloric acid to obtain a mixture. Heat 100g of petroleum asphalt to 180℃ until melted. Then, add 20g of modified hydrotalcite, 50g of the mixture, and 10g of SBS rubber powder obtained in step S1 and perform a shear emulsification reaction in a dispersing emulsifier. The temperature of the shear emulsification reaction is 180℃ and the emulsification time is 2h to obtain modified asphalt.

[0084] Comparative Example 1

[0085] A method for preparing high-performance aging-resistant concrete includes the following steps:

[0086] (1) Weigh each raw material according to the formula, and mix 60kg of 42.5 rapid hardening sulfoaluminate cement, 13kg of fly ash, 70kg of sand and 100kg of crushed stone to obtain a solid mixture;

[0087] (2) Add 30 kg of water, 0.8 kg of polyether modified polysiloxane defoamer and 1.5 kg of polycarboxylate water-reducing agent to the solid mixture obtained in step (1), and stir at 250 r / min for 25 min to obtain a slurry mixture;

[0088] (3) Add 13 kg of asphalt and 6 kg of modified fiber to the slurry mixture obtained in step (2), and stir for 15 min at a speed of 350 r / min to obtain the high-performance aging-resistant concrete.

[0089] The fineness modulus of the sand is 1.6-2.2, and the average particle size is 0.15-0.25 mm; the particle size of the crushed stone is 6-10 mm.

[0090] The method for preparing modified fibers includes the following steps:

[0091] (a) Mix 100g of glass fiber and 200g of lignin fiber evenly, then add 800mL of sodium hydroxide solution with a mass concentration of 6% and soak for 8h. After soaking, filter, wash and dry to obtain pretreated fiber.

[0092] (b) Add the pretreated fiber (100g) obtained in step (a) to 600mL of anhydrous ethanol, then add 5g of aminopropyltriethoxysilane and 8g of trihexyltetradecylphosphine chloride, stir at 70°C for 4h, filter, wash and dry after the reaction is complete to obtain mixed fiber;

[0093] (c) Add 4g of γ-glycidoxypropyltrimethoxysilane to 40mL of anhydrous ethanol and stir until homogeneous. Then add 25g of polyester fiber and 50g of the mixed fiber obtained in step (b). Ball mill at 1500r / min for 1.5h. After ball milling, dry to obtain the modified fiber.

[0094] Comparative Example 2

[0095] A method for preparing high-performance aging-resistant concrete includes the following steps:

[0096] (1) Weigh each raw material according to the formula, and mix 60kg of 42.5 rapid hardening sulfoaluminate cement, 13kg of fly ash, 70kg of sand and 100kg of crushed stone to obtain a solid mixture;

[0097] (2) Add 30 kg of water, 0.8 kg of polyether modified polysiloxane defoamer and 1.5 kg of polycarboxylate water-reducing agent to the solid mixture obtained in step (1), and stir at 250 r / min for 25 min to obtain a slurry mixture;

[0098] (3) Add 13 kg of modified asphalt and 6 kg of mixed fiber to the slurry mixture obtained in step (2), and stir for 15 min at a speed of 350 r / min to obtain the high-performance aging-resistant concrete.

[0099] The fineness modulus of the sand is 1.6-2.2, and the average particle size is 0.15-0.25 mm; the particle size of the crushed stone is 6-10 mm.

[0100] The mixed fiber is composed of glass fiber, lignin fiber and polyester fiber mixed evenly in a mass ratio of 10:20:15.

[0101] The method for preparing the modified asphalt includes the following steps:

[0102] S1. 100g of hydrotalcite was added to 800mL of distilled water and stirred at room temperature for 2h. Then 4g of octadecyltrimethylammonium chloride was added and refluxed at 70℃ for 3h. After the reaction was completed, the product was filtered, washed and dried to obtain a solid product. Then 100g of the obtained solid product was added to 700mL of anhydrous ethanol, followed by 8g of cellulose ether and 13g of 2-hydroxy-4-n-octyloxybenzophenone. The product was stirred at 80℃ for 4h. After the reaction was completed, the ethanol was removed by rotary evaporation to obtain modified hydrotalcite.

[0103] S2. Add 2g of octylphenol polyoxyethylene ether to 100mL of water and stir until homogeneous. Then add 4g of fatty alcohol polyoxyethylene ether sodium sulfate and stir until homogeneous. Adjust the pH value to 4 with hydrochloric acid to obtain a mixture. Heat 100g of petroleum asphalt to 170℃ until melted. Then, add 15g of modified hydrotalcite, 40g of the mixture, and 8g of SBS rubber powder obtained in step S1 and perform a shear emulsification reaction in a dispersing emulsifier. The temperature of the shear emulsification reaction is 170℃ and the emulsification time is 1h to obtain modified asphalt.

[0104] Compressive strength: The concrete prepared in Examples 1-3 and Comparative Examples 1-2 was made into multiple cubic specimens with a side length of 150 mm. They were cured in a standard curing room at 20 °C and 90% relative humidity. After curing for 28 days, the compressive strength was tested. The load loading rate was controlled at 0.6 MPa / s. The specific test results are shown in Table 1.

[0105] Flexural strength: A beam-shaped specimen of 150mm×150mm×550mm was cured for 28 days at a temperature of 20±3℃ and a relative humidity of over 90%, and then failed under a double-support load with a clear span of 450mm. The flexural strength value was calculated according to the specified method.

[0106] This experiment selected three specimens from each of the above embodiments and tested the flexural strength F of each specimen. n The average flexural strength F of the three specimens in this example was calculated. Sn F Sn With F n The allowable difference is ±10%. If the difference between the two values ​​is within ±10%, then the flexural strength of this set of embodiments is F. Sn Conversely, if the result is not satisfactory, then the experiment should be repeated.

[0107] Both the compressive strength and flexural strength mentioned above can be tested using a universal testing machine. The calculation methods for both are common knowledge to those skilled in the art, and will not be elaborated upon here.

[0108] Freeze-thaw resistance test: Concrete specimens prepared according to Examples 1-3 and Comparative Examples 1-2 were used in accordance with GB / T 50082-2009 (Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete). The specimens were 100mm×100mm×100mm in size and cured for 24 days at 20℃ and relative humidity above 90%. After curing, the specimens were removed and immersed in water at 20℃ for 4 days before the freeze-thaw test was started. Then, the freeze-thaw cycle test was carried out according to the slow freezing method mentioned in GB / T 50082-2009, and the maximum number of freeze-thaw cycles was used for evaluation. The test results are shown in Table 1.

[0109] Table 1

[0110] project Compressive strength / MPa Flexural strength / MPa Maximum number of freeze-thaw cycles / times Example 1 69.4 16.2 315 Example 2 66.5 15.6 303 Example 3 68.3 16.8 306 Comparative Example 1 48.1 10.7 208 Comparative Example 2 46.9 11.3 223

[0111] As shown in Table 1, the high-performance aging-resistant concrete prepared in Examples 1-3 of this invention exhibits good compressive and flexural strength, with a maximum compressive strength of up to 69.4 MPa and a maximum flexural strength of up to 16.8 MPa, while also possessing excellent freeze-thaw resistance. In contrast, in Comparative Example 1, the lack of modification of the asphalt, and in Comparative Example 2, the lack of modification of the mixed fibers, both resulted in uneven dispersion, poor compatibility, or poor aging resistance of the concrete materials, leading to instability in the concrete system and varying degrees of performance degradation.

[0112] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-performance, aging-resistant concrete, characterized in that, By weight, it includes the following raw materials: 500-700 parts cement, 50-70 parts modified fiber, 110-160 parts fly ash, 600-800 parts sand, 900-1100 parts crushed stone, 5-10 parts defoamer, 10-20 parts water-reducing agent, 100-150 parts modified asphalt, and 250-350 parts water. The method for preparing the modified fiber includes the following steps: (a) Glass fiber and lignin fiber are mixed evenly, and then impregnated in sodium hydroxide solution. After impregnation, the mixture is filtered, washed and dried to obtain pretreated fiber. (b) The pretreated fiber obtained in step (a) was added to anhydrous ethanol, followed by the addition of aminopropyltriethoxysilane and trihexyltetradecylphosphine chloride. The mixture was stirred and reacted. After the reaction was completed, the mixture was filtered, washed and dried to obtain the mixed fiber. (c) Add γ-glycidyl etheroxypropyltrimethoxysilane to anhydrous ethanol and stir until homogeneous. Then add polyester fiber and the mixed fiber obtained in step (b), and ball mill. After ball milling, dry to obtain the modified fiber. The method for preparing the modified asphalt includes the following steps: S1. Add hydrotalcite to distilled water and stir at room temperature for 1-3 hours. Then add octadecyltrimethylammonium chloride and reflux at 60-80°C for 2-4 hours. After the reaction is complete, filter, wash and dry to obtain a solid product. Then add the obtained solid product to anhydrous ethanol, followed by cellulose ether and 2-hydroxy-4-n-octyloxybenzophenone. Stir and react. After the reaction is complete, rotary evaporate to obtain modified hydrotalcite. S2. Add octylphenol polyoxyethylene ether to water and stir evenly. Then add sodium fatty alcohol polyoxyethylene ether sulfate and stir evenly. Adjust the pH value to 3-5 with hydrochloric acid to obtain a mixture. Heat petroleum asphalt to melt. Then, the modified hydrotalcite, mixture and SBS rubber powder obtained in step S1 are sheared and emulsified in a dispersion emulsifier to obtain modified asphalt.

2. The high-performance aging-resistant concrete according to claim 1, characterized in that, The cement is one or more of 42.5 ordinary Portland cement, 52.5 ordinary Portland cement, and 42.5 rapid-hardening sulfoaluminate cement; the fineness modulus of the sand is 1.6-2.2, and the average particle size is 0.15-0.25 mm; the particle size of the crushed stone is 6-10 mm.

3. The high-performance aging-resistant concrete according to claim 1, characterized in that, The defoamer is one or more of polyether defoamers, silicone defoamers, and polyether-modified polysiloxane defoamers; the water-reducing agent is one of sodium methylene dinaphthalene sulfonate and polycarboxylate water-reducing agents.

4. The high-performance aging-resistant concrete according to claim 1, characterized in that, In step (a), the mass ratio of glass fiber to lignin fiber is 1:1-3; the mass concentration of sodium hydroxide solution is 4-8%, and the impregnation time is 5-10h; in step (b), the mass ratio of pretreated fiber, aminopropyltriethoxysilane, and trihexyltetradecylphosphine chloride is 100:3-6:5-10; the stirring reaction temperature is 50-80℃, and the reaction time is 3-5h.

5. The high-performance aging-resistant concrete according to claim 1, characterized in that, In step (c), the mass ratio of polyester fiber, γ-glycidyl etheroxypropyltrimethoxysilane, and mixed fiber is 20-30:2-5:40-60; the ball milling speed is 1000-2000 r / min, and the ball milling time is 1-2 h.

6. The high-performance aging-resistant concrete according to claim 1, characterized in that, In step S1, the mass ratio of hydrotalcite and octadecyltrimethylammonium chloride is 100:3-5; the mass ratio of the solid product, cellulose ether, and 2-hydroxy-4-n-octyloxybenzophenone is 100:5-10:10-15; the stirring reaction temperature is 70-90℃, and the time is 3-5h; in step S2, the mass ratio of octylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether sodium sulfate, and water is 1-3:3-5:50-70; the mass ratio of asphalt, modified hydrotalcite, mixture, and SBS rubber powder is 100:10-20:30-50:5-10; the melting temperature is 160-180℃; and the shear emulsification reaction temperature is 160-180℃, and the emulsification time is 0.5-2h.

7. A method for preparing high-performance aging-resistant concrete as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) Weigh each raw material according to the formula, and mix cement, fly ash, sand and crushed stone to obtain a solid mixture; (2) Add water, defoamer, and water-reducing agent to the solid mixture obtained in step (1), and stir evenly to obtain a slurry mixture; (3) Add the modified asphalt and modified fiber to the slurry mixture obtained in step (2), and stir to obtain the high-performance aging-resistant concrete.

8. The method for preparing high-performance aging-resistant concrete according to claim 7, characterized in that, The stirring speed in step (2) is 200-300 r / min and the stirring time is 15-30 min; the stirring speed in step (3) is 300-400 r / min and the stirring time is 10-20 min.