High-performance anti-aging concrete and preparation method thereof

Abstract

The invention discloses high-performance anti-aging concrete and a preparation method thereof, and belongs to the technical field of concrete materials, the high-performance anti-aging concrete comprises the following raw materials by weight: 500-700 parts of cement, 50-70 parts of modified fiber, 110-160 parts of fly ash, 600-800 parts of sand, 900-1100 parts of gravel, 5-10 parts of an antifoaming agent, 10-20 parts of a water reducer, 40-60 parts of modified asphalt, and 250-350 parts of water. According to the high-performance anti-aging concrete provided by the invention, the modified asphalt and the modified fibers are added and jointly have a reinforcing effect on a hardened interface of the concrete, so that the mechanical property of the concrete is greatly improved; due to the fact that the 2-hydroxy-4-n-octyloxybenzophenone light absorber is introduced into the modified asphalt and the gamma-glycidyl ether oxypropyl trimethoxy silane adhesive is added into the modified fiber, the outdoor aging resistance and pulverization resistance of the concrete are improved, and the concrete has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete materials, and in particular relates to high-performance aging-resistant concrete and a preparation method thereof. Background Art

[0002] In modern architecture, concrete is the most widely used and largest amount of building structural material. Concrete is widely used in buildings and infrastructure because of its characteristics of easy molding, convenient transportation, high plasticity and high strength. As the most widely used building material, concrete plays an irreplaceable role and function in modern construction, water conservancy, ports, roads and bridges.

[0003] With the continuous development of concrete materials, people's performance requirements for concrete are not limited to compressive strength, but on the basis of strength, they pay more attention to the balance and coordination of comprehensive indicators such as durability, deformation performance, fire and explosion resistance, water seepage resistance, toughness, corrosion resistance, thermal insulation, health and environmental protection, and cost reduction. The requirements for various performance indicators of concrete are clearer, more detailed and specific than before. At the same time, the improvement of construction equipment level and the continuous emergence and promotion of new construction technology have enabled concrete technology to adapt to different design, engineering and use requirements, and it has developed rapidly.

[0004] Chinese patent application No. 201610801767.3 discloses a method for preparing fiber-reinforced high-damping polymer concrete, in which the concrete includes cement, water, fly ash, sand, crushed stone, polymer emulsion, high-efficiency water reducer, defoamer, dispersant and PVA fiber. The above patent uses a dispersant to increase the dispersibility of polymer emulsion in cement-based concrete. However, because polymer emulsion and cement-based cementitious materials easily compete for active silica in cement-based silicate, cement hydration is incomplete, cement particles aggregate, and then voids are formed between concrete, concrete hardness is poor, and anti-seepage and waterproofing effects are poor.

[0005] Therefore, it is particularly important to research and develop a concrete with high strength and aging resistance in order to delay the corrosion of concrete and increase its service life. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a high-performance aging-resistant concrete and a preparation method thereof. The concrete has good compactness, strong crack resistance and impact resistance, and prevents cracking. At the same time, it is not easy to pulverize under long-term use and has good durability.

[0007] To achieve the above object, the present invention provides the following technical solutions:

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

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

[0010] Preferably, the defoamer is one or more of a polyether defoamer, a silicone defoamer, and a polyether-modified polysiloxane defoamer; and the water reducer is one of sodium methylene dinaphthalene sulfonate and a polycarboxylic acid-based water reducer.

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

[0012] (a) mixing glass fiber and lignin fiber uniformly, then adding them into a sodium hydroxide solution for impregnation, filtering, washing and drying after the impregnation is completed to obtain pretreated fiber;

[0013] (b) adding the pretreated fiber obtained in step (a) into anhydrous ethanol, and then adding aminopropyltriethoxysilane and trihexyltetradecylphosphine chloride, stirring to react, and filtering, washing, and drying after the reaction is completed to obtain a mixed fiber;

[0014] (c) adding γ-glycidyloxypropyltrimethoxysilane to anhydrous ethanol, stirring evenly, then adding polyester fiber and the mixed fiber obtained in step (b), ball milling, and drying after ball milling to obtain the modified fiber.

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

[0016] Preferably, in step (c), the mass ratio of the polyester fiber, γ-glycidyloxypropyltrimethoxysilane and the 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 comprises the following steps:

[0018] S1. Adding hydrotalcite to distilled water, stirring at room temperature for 1-3 hours, then adding octadecyltrimethylammonium chloride, reflux reacting at 60-80° C. for 2-4 hours, filtering, washing, and drying after the reaction is completed to obtain a solid product; then adding the obtained solid product to anhydrous ethanol, followed by adding cellulose ether and 2-hydroxy-4-n-octyloxybenzophenone, stirring to react, and performing rotary evaporation after the reaction is completed to obtain a modified hydrotalcite;

[0019] S2, adding octylphenol polyoxyethylene ether into water and stirring evenly, then adding fatty alcohol polyoxyethylene ether sodium sulfate, stirring evenly and adjusting the pH value to 3-5 with hydrochloric acid to obtain a mixed solution; heating petroleum asphalt to melt, then subjecting the modified hydrotalcite, mixed solution and SBS rubber powder obtained in step S1 to shear emulsification reaction in a dispersing emulsifier to obtain modified asphalt.

[0020] Preferably, in step S1, the mass ratio of the 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°C and the time is 3-5h; the mass ratio of octylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether sodium sulfate and water in step S2 is 1-3:3-5:50-70; the mass ratio of asphalt, modified hydrotalcite, mixed solution and SBS rubber powder is 100:10-20:30-50:5-10; the melting temperature is 160-180°C; the temperature of the shear emulsification reaction is 160-180°C and the emulsification time is 0.5-2h.

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

[0022] (1) Weighing various raw materials according to the formula, mixing cement, fly ash, sand, and crushed stone to obtain a solid mixture;

[0023] (2) adding water, a defoaming agent, and a water reducing agent to the solid mixture obtained in step (1), and stirring to obtain a slurry mixture;

[0024] (3) Adding modified asphalt and modified fiber to the slurry mixture obtained in step (2), and stirring 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 the present invention comprises the following steps: firstly, hydrotalcite is modified by inserting octadecyltrimethylammonium chloride between the layers of the hydrotalcite to perform intercalation modification, thereby increasing the interlayer spacing of the hydrotalcite. On the one hand, the uniformly dispersed hydrotalcite layers can extend the diffusion path of oxygen, thereby greatly increasing the anti-aging performance of asphalt. On the other hand, it is also beneficial for subsequent 2-hydroxy-4-n-octyloxybenzophenone to enter between the layers of the hydrotalcite. Then, octylphenol polyoxyethylene ether and sodium sulfate of fatty alcohol polyoxyethylene ether are added to prepare an aqueous solution. The aqueous solution, 2-hydroxy-4-n-octyloxybenzophenone, modified hydrotalcite, SBS rubber powder and asphalt are mixed and modified. 2-hydroxy-4-n-octyloxybenzophenone is added to the modified hydrotalcite layer to form an aqueous solution. - n-Octyloxybenzophenone has excellent UV resistance and can greatly improve the outdoor aging performance of asphalt. At the same time, the added octylphenol polyoxyethylene ether organically modifies the surface and edge of the hydrotalcite layer, thereby changing the inherent hydrophilicity of the hydrotalcite, improving the organic compatibility of the hydrotalcite with asphalt, making it more tightly combined with asphalt, and the modified hydrotalcite is more evenly dispersed in the asphalt; and the sodium sulfate of fatty alcohol polyoxyethylene ether can emulsify the asphalt at the same time, and the addition of SBS to the asphalt for toughening modification makes the asphalt undergo an emulsification reaction while being modified, and has 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 the present invention has the advantages of soft texture and high single-filament tensile strength. The polyester fiber added to the concrete can play a good reinforcement effect, improve the bite ability inside the concrete, inhibit the generation and development of microcracks, and improve the low-temperature crack resistance of the concrete; by blending and modifying the glass fiber and the lignin fiber, firstly alkali-activating them to increase the porosity inside the lignin and the hydroxyl activity on the surface, and then adding trihexyltetradecylphosphine chloride and aminopropyltriethoxysilane, so that the aminopropyltriethoxysilane and the glass fiber are bonded to each other. Siloxane is grafted onto the surface of the fiber and lignin fiber, and trihexyltetradecylphosphonium chloride is used as a surfactant to make the fiber dispersed more evenly in the concrete, thereby overcoming the problem that the fiber is prone to agglomeration during the mixing process with the concrete, which leads to inconsistent strength of various parts of the concrete and reduces the overall strength of the concrete; finally, polyester fiber and γ-glycidyloxypropyltrimethoxysilane are added for ball milling to adhere the lignin fiber and the glass fiber to the surface of the polyester fiber. Under the action of silane, the modified fiber is not easy to fall off, thereby reducing the phenomenon of concrete pulverization.

[0029] (3) The high-performance aging-resistant concrete provided by the present invention has a strengthening effect on 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, due to the introduction of 2-hydroxy-4-octyloxybenzophenone light absorber in the modified asphalt and γ-glycidyloxypropyltrimethoxysilane adhesive in the modified fiber, the outdoor aging resistance and powdering resistance of the concrete are improved, and the concrete has good application prospects. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The fly ash was purchased from Shijiazhuang Yuanjing Mineral Products Co., Ltd., with a mesh size of 325 mesh;

[0032] The polyether defoamer was purchased from Shandong Juneng Chemical Co., Ltd. with the brand name JN-306;

[0033] The organosilicon defoamer was purchased from Sichuan Wanbang Qingyuan Environmental Technology Co., Ltd., with the brand name WB521;

[0034] The polyether-modified polysiloxane defoamer was purchased from Dongguan Defeng Defoamer Co., Ltd. with the brand name DF-2684;

[0035] The polycarboxylic acid water reducer was purchased from Liaoning Kelong Fine Chemical Co., Ltd., with the brand name SP409;

[0036] The sodium methylene dinaphthalene sulfonate was purchased from Shandong Xiangzhao New Materials 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 9-13 μm and a length of 3 mm;

[0039] The lignin fiber was 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 10-25 μm and a length of 12 mm;

[0041] The hydrotalcite was purchased from Jinan Zi'an Chemical Co., Ltd., with a particle size of 5-20 μm;

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

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

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

[0045] Example 1

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

[0047] (1) Weighing the raw materials according to the formula, 60 kg of 42.5 fast-hardening sulphoaluminate cement, 13 kg of fly ash, 70 kg of sand, and 100 kg of crushed stone were mixed and stirred to obtain a solid mixture;

[0048] (2) adding 30 kg of water, 0.8 kg of a polyether-modified polysiloxane defoamer, and 1.5 kg of a polycarboxylic acid-based water reducer to the solid mixture obtained in step (1), and stirring at a speed of 250 r / min for 25 min to obtain a slurry mixture;

[0049] (3) 13 kg of modified asphalt and 6 kg of modified fiber were added to the slurry mixture obtained in step (2), and stirred at a rotation speed of 350 r / min for 15 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 the modified fiber comprises the following steps:

[0052] (a) 100 g of glass fiber and 200 g of lignin fiber were mixed uniformly, and then added into 800 mL of 6% sodium hydroxide solution and immersed for 8 h. After the immersion was completed, the pretreated fiber was filtered, washed, and dried to obtain the pretreated fiber;

[0053] (b) adding the pretreated fiber (100 g) obtained in step (a) into 600 mL of anhydrous ethanol, and then adding 5 g of aminopropyltriethoxysilane and 8 g of trihexyltetradecylphosphine chloride, stirring and reacting at 70° C. for 4 h, filtering, washing and drying after the reaction is completed to obtain a mixed fiber;

[0054] (c) adding 4 g of γ-glycidyloxypropyltrimethoxysilane to 40 mL of anhydrous ethanol and stirring evenly, then adding 25 g of polyester fiber and the mixed fiber (50 g) obtained in step (b), ball milling at 1500 r / min for 1.5 h, and drying after ball milling to obtain the modified fiber.

[0055] The preparation method of the modified asphalt comprises the following steps:

[0056] S1. Add 100 g of hydrotalcite to 800 mL of distilled water, stir at room temperature for 2 h, then add 4 g of octadecyltrimethylammonium chloride, reflux at 70 ° C for 3 h, filter, wash and dry the mixture after the reaction is completed to obtain a solid product; then add the obtained solid product (100 g) to 700 mL of anhydrous ethanol, then add 8 g of cellulose ether and 13 g of 2-hydroxy-4-n-octyloxybenzophenone, stir at 80 ° C for 4 h, and after the reaction is completed, remove the ethanol by rotary evaporation to obtain a modified hydrotalcite;

[0057] S2. Add 2 g of octylphenol polyoxyethylene ether to 100 mL of water and stir evenly, then add 4 g of fatty alcohol polyoxyethylene ether sodium sulfate, stir evenly and adjust the pH value to 4 with hydrochloric acid to obtain a mixed solution; heat 100 g of petroleum asphalt to 170° C. until it is melted, then subject the modified hydrotalcite (15 g) obtained in step S1, 40 g of the mixed solution and 8 g of SBS rubber powder to a shear emulsification reaction in a dispersing emulsifier, the shear emulsification reaction temperature is 170° C., and the emulsification time is 1 h to obtain modified asphalt.

[0058] Example 2

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

[0060] (1) Weighing the raw materials according to the formula, 50 kg of 42.5 ordinary Portland cement, 11 kg of fly ash, 60 kg of sand, and 90 kg of crushed stone were mixed and stirred to obtain a solid mixture;

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

[0062] (3) 10 kg of modified asphalt and 5 kg of modified fiber were added to the slurry mixture obtained in step (2), and stirred at a rotation speed of 300 r / min for 10 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 the modified fiber comprises the following steps:

[0065] (a) 100 g of glass fiber and 100 g of lignin fiber were mixed uniformly, and then added into 800 mL of a 4% sodium hydroxide solution and immersed for 5 h. After the immersion was completed, the pretreated fiber was filtered, washed, and dried to obtain the pretreated fiber;

[0066] (b) adding the pretreated fiber (100 g) obtained in step (a) into 600 mL of anhydrous ethanol, and then adding 3 g of aminopropyltriethoxysilane and 5 g of trihexyltetradecylphosphine chloride, stirring and reacting at 50° C. for 3 h, filtering, washing and drying after the reaction is completed to obtain a mixed fiber;

[0067] (c) adding 2 g of γ-glycidyloxypropyltrimethoxysilane to 40 mL of anhydrous ethanol and stirring evenly, then adding 20 g of polyester fiber and the mixed fiber (40 g) obtained in step (b), ball milling at 1000 r / min for 1 h, and drying after ball milling to obtain the modified fiber.

[0068] The preparation method of the modified asphalt comprises the following steps:

[0069] S1. Add 100 g of hydrotalcite to 800 mL of distilled water, stir at room temperature for 1 h, then add 3 g of octadecyltrimethylammonium chloride, reflux at 60 ° C for 2 h, filter, wash and dry the mixture after the reaction is completed to obtain a solid product; then add the obtained solid product (100 g) to 700 mL of anhydrous ethanol, then add 5 g of cellulose ether and 10 g of 2-hydroxy-4-n-octyloxybenzophenone, stir at 70 ° C for 3 h, and after the reaction is completed, remove the ethanol by rotary evaporation to obtain a modified hydrotalcite;

[0070] S2. Add 1 g of octylphenol polyoxyethylene ether to 100 mL of water and stir evenly, then add 3 g of fatty alcohol polyoxyethylene ether sodium sulfate, stir evenly and adjust the pH value to 3 with hydrochloric acid to obtain a mixed solution; heat 100 g of petroleum asphalt to 160° C. until it is melted, then subject the modified hydrotalcite (10 g) obtained in step S1, 30 g of the mixed solution and 5 g of SBS rubber powder to a shear emulsification reaction in a dispersing emulsifier, the shear emulsification reaction temperature is 160° C., and the emulsification time is 0.5 h to obtain modified asphalt.

[0071] Example 3

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

[0073] (1) Weighing the raw materials according to the formula, 70 kg of 52.5 ordinary Portland cement, 16 kg of fly ash, 80 kg of sand, and 110 kg of crushed stone were mixed and stirred to obtain a solid mixture;

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

[0075] (3) 15 kg of modified asphalt and 7 kg of modified fiber were added to the slurry mixture obtained in step (2), and stirred at a rotation speed of 400 r / min for 20 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 preparation method of the modified fiber comprises the following steps:

[0078] (a) 100 g of glass fiber and 300 g of lignin fiber were mixed uniformly, and then added into 800 mL of 8% sodium hydroxide solution and immersed for 10 h. After the immersion, the mixture was filtered, washed, and dried to obtain pretreated fiber;

[0079] (b) adding the pretreated fiber (100 g) obtained in step (a) into 600 mL of anhydrous ethanol, and then adding 6 g of aminopropyltriethoxysilane and 10 g of trihexyltetradecylphosphine chloride, stirring and reacting at 80° C. for 5 h, filtering, washing and drying after the reaction is completed to obtain a mixed fiber;

[0080] (c) adding 5 g of γ-glycidyloxypropyltrimethoxysilane to 40 mL of anhydrous ethanol and stirring evenly, then adding 30 g of polyester fiber and the mixed fiber (60 g) obtained in step (b), ball milling at 2000 r / min for 2 h, and drying after ball milling to obtain the modified fiber.

[0081] The preparation method of the modified asphalt comprises the following steps:

[0082] S1. Add 100 g of hydrotalcite to 800 mL of distilled water, stir at room temperature for 3 h, then add 5 g of octadecyltrimethylammonium chloride, reflux at 80 ° C for 4 h, filter, wash and dry the mixture after the reaction is completed to obtain a solid product; then add the obtained solid product (100 g) to 700 mL of anhydrous ethanol, then add 10 g of cellulose ether and 15 g of 2-hydroxy-4-n-octyloxybenzophenone, stir at 90 ° C for 5 h, and after the reaction is completed, remove the ethanol by rotary evaporation to obtain a modified hydrotalcite;

[0083] S2. Add 3 g of octylphenol polyoxyethylene ether to 100 mL of water and stir evenly, then add 5 g of sodium sulfate of fatty alcohol polyoxyethylene ether, stir evenly and adjust the pH value to 5 with hydrochloric acid to obtain a mixed solution; heat 100 g of petroleum asphalt to 180° C. until it is melted, then subject the modified hydrotalcite (20 g) obtained in step S1, 50 g of the mixed solution and 10 g of SBS rubber powder to a shear emulsification reaction in a dispersing emulsifier, the shear emulsification reaction temperature is 180° C., and the emulsification time is 2 h to obtain modified asphalt.

[0084] Comparative Example 1

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

[0086] (1) Weighing the raw materials according to the formula, 60 kg of 42.5 fast-hardening sulphoaluminate cement, 13 kg of fly ash, 70 kg of sand, and 100 kg of crushed stone were mixed and stirred to obtain a solid mixture;

[0087] (2) adding 30 kg of water, 0.8 kg of a polyether-modified polysiloxane defoamer, and 1.5 kg of a polycarboxylic acid-based water reducer to the solid mixture obtained in step (1), and stirring at a speed of 250 r / min for 25 min to obtain a slurry mixture;

[0088] (3) 13 kg of asphalt and 6 kg of modified fiber were added to the slurry mixture obtained in step (2), and stirred at a rotation speed of 350 r / min for 15 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 preparation method of the modified fiber comprises the following steps:

[0091] (a) 100 g of glass fiber and 200 g of lignin fiber were mixed uniformly, and then added into 800 mL of 6% sodium hydroxide solution and immersed for 8 h. After the immersion was completed, the pretreated fiber was filtered, washed, and dried to obtain the pretreated fiber;

[0092] (b) adding the pretreated fiber (100 g) obtained in step (a) into 600 mL of anhydrous ethanol, and then adding 5 g of aminopropyltriethoxysilane and 8 g of trihexyltetradecylphosphine chloride, stirring and reacting at 70° C. for 4 h, filtering, washing and drying after the reaction is completed to obtain a mixed fiber;

[0093] (c) adding 4 g of γ-glycidyloxypropyltrimethoxysilane to 40 mL of anhydrous ethanol and stirring evenly, then adding 25 g of polyester fiber and the mixed fiber (50 g) obtained in step (b), ball milling at 1500 r / min for 1.5 h, and drying after ball milling to obtain the modified fiber.

[0094] Comparative Example 2

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

[0096] (1) Weighing the raw materials according to the formula, 60 kg of 42.5 fast-hardening sulphoaluminate cement, 13 kg of fly ash, 70 kg of sand, and 100 kg of crushed stone were mixed and stirred to obtain a solid mixture;

[0097] (2) adding 30 kg of water, 0.8 kg of a polyether-modified polysiloxane defoamer, and 1.5 kg of a polycarboxylic acid-based water reducer to the solid mixture obtained in step (1), and stirring at a speed of 250 r / min for 25 min to obtain a slurry mixture;

[0098] (3) 13 kg of modified asphalt and 6 kg of mixed fiber were added to the slurry mixture obtained in step (2), and stirred at a rotation speed of 350 r / min for 15 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 formed by uniformly mixing glass fiber, lignin fiber and polyester fiber in a mass ratio of 10:20:15.

[0101] The preparation method of the modified asphalt comprises the following steps:

[0102] S1. Add 100 g of hydrotalcite to 800 mL of distilled water, stir at room temperature for 2 h, then add 4 g of octadecyltrimethylammonium chloride, reflux at 70 ° C for 3 h, filter, wash and dry the mixture after the reaction is completed to obtain a solid product; then add the obtained solid product (100 g) to 700 mL of anhydrous ethanol, then add 8 g of cellulose ether and 13 g of 2-hydroxy-4-n-octyloxybenzophenone, stir at 80 ° C for 4 h, and after the reaction is completed, remove the ethanol by rotary evaporation to obtain a modified hydrotalcite;

[0103] S2. Add 2 g of octylphenol polyoxyethylene ether to 100 mL of water and stir evenly, then add 4 g of fatty alcohol polyoxyethylene ether sodium sulfate, stir evenly and adjust the pH value to 4 with hydrochloric acid to obtain a mixed solution; heat 100 g of petroleum asphalt to 170° C. until it is melted, then subject the modified hydrotalcite (15 g) obtained in step S1, 40 g of the mixed solution and 8 g of SBS rubber powder to a shear emulsification reaction in a dispersing emulsifier, the shear emulsification reaction temperature is 170° C., and the emulsification time is 1 h to obtain modified asphalt.

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

[0105] Flexural strength: After curing for 28 days at a temperature of 20+3℃ and a relative humidity of more than 90%, a beam specimen of 150mm×150mm×550mm is destroyed under the action of a double-support load with a clear span of 450mm, and the flexural strength value is calculated according to the prescribed method;

[0106] In this test, three specimens from each of the above embodiments were selected to test the flexural strength F of each specimen. n , and calculate the average flexural strength F of the three specimens in this embodiment Sn , where F Sn With F n The allowable difference is ±10%. If the difference between the two values ​​is within ±10%, the flexural strength of the embodiment is F. Sn Otherwise, the group of experiments should be repeated.

[0107] The above-mentioned compressive strength and flexural strength can be tested by a universal testing machine. The calculation methods of both are common knowledge of technicians in this field and will not be described in detail here.

[0108] Freeze-thaw resistance test: According to GB / T 50082-2009 (standard for test methods for long-term performance and durability of ordinary concrete), test specimens were made with the concrete prepared in Examples 1-3 and Comparative Examples 1-2. The size of the test specimens was 100 mm×100 mm×100 mm. The specimens were cured for 24 days at 20°C and a relative humidity of more than 90%. The test specimens were then taken out and immersed in water at 20°C 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 freeze-thaw times / 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 can be seen from Table 1, the high-performance aging-resistant concrete prepared in Examples 1-3 of the present invention has good compressive strength 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, and also has excellent freeze-thaw resistance. However, since the asphalt in Comparative Example 1 was not modified and the mixed fiber in Comparative Example 2 was not modified, the concrete materials were unevenly dispersed or had poor compatibility or poor aging resistance, resulting in an unstable concrete system, resulting in varying degrees of performance degradation.

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

Claims

1. A high performance aging resistant concrete, characterized in that: Calculated by weight, the raw materials include: 500-700 parts of cement, 50-70 parts of modified fiber, 110-160 parts of fly ash, 600-800 parts of sand, 900-1100 parts of crushed stone, 5-10 parts of defoaming agent, 10-20 parts of water reducing agent, 100-150 parts of modified asphalt and 250-350 parts of water.

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 fast-hardening sulphoaluminate cement; the fineness modulus of the sand is 1.6-2.2, and the average particle size is 0.15-0.25mm; the particle size of the crushed stone is 6-10mm.

3. The high performance aging resistant concrete according to claim 1, characterized in that: The defoamer is one or more of a polyether defoamer, an organosilicon defoamer, and a polyether-modified polysiloxane defoamer; the water reducer is one of sodium methylene dinaphthalene sulfonate and a polycarboxylic acid-based water reducer.

4. The high performance aging resistant concrete according to claim 1, characterized in that: The method for preparing the modified fiber comprises the following steps: (a) mixing glass fiber and lignin fiber uniformly, then adding them into a sodium hydroxide solution for impregnation, filtering, washing and drying after the impregnation to obtain pretreated fiber; (b) adding the pretreated fiber obtained in step (a) into anhydrous ethanol, and then adding aminopropyltriethoxysilane and trihexyltetradecylphosphonium chloride, stirring to react, and filtering, washing, and drying after the reaction is completed to obtain a mixed fiber; (c) adding γ-glycidyloxypropyltrimethoxysilane to anhydrous ethanol, stirring evenly, then adding polyester fiber and the mixed fiber obtained in step (b), ball milling, and drying after ball milling to obtain the modified fiber.

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

6. The high performance aging resistant concrete according to claim 4, characterized in that: In step (c), the mass ratio of the polyester fiber, γ-glycidyloxypropyltrimethoxysilane and the 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.

7. The high performance aging resistant concrete according to claim 1, characterized in that: The preparation method of the modified asphalt comprises the following steps: S1. Adding hydrotalcite to distilled water, stirring at room temperature for 1-3 hours, then adding octadecyltrimethylammonium chloride, reflux reacting at 60-80° C. for 2-4 hours, filtering, washing, and drying after the reaction is completed to obtain a solid product; then adding the obtained solid product to anhydrous ethanol, followed by adding cellulose ether and 2-hydroxy-4-n-octyloxybenzophenone, stirring to react, and performing rotary evaporation after the reaction is completed to obtain a modified hydrotalcite; S2, adding octylphenol polyoxyethylene ether into water and stirring evenly, then adding fatty alcohol polyoxyethylene ether sodium sulfate, stirring evenly and adjusting the pH value to 3-5 with hydrochloric acid to obtain a mixed solution; heating petroleum asphalt to melt, then subjecting the modified hydrotalcite, mixed solution and SBS rubber powder obtained in step S1 to shear emulsification reaction in a dispersing emulsifier to obtain modified asphalt.

8. The high performance aging resistant concrete according to claim 7, characterized in that: The mass ratio of the hydrotalcite and octadecyltrimethylammonium chloride in step S1 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°C and the time is 3-5h; the mass ratio of octylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether sodium sulfate and water in step S2 is 1-3:3-5:50-70; the mass ratio of asphalt, modified hydrotalcite, mixed solution and SBS rubber powder is 100:10-20:30-50:5-10; the melting temperature is 160-180°C; the temperature of the shear emulsification reaction is 160-180°C and the emulsification time is 0.5-2h.

9. A method for preparing high-performance aging-resistant concrete according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Weighing the raw materials according to the formula, mixing cement, fly ash, sand and gravel to obtain a solid mixture; (2) adding water, a defoaming agent and a water reducing agent to the solid mixture obtained in step (1), and stirring to obtain a slurry mixture; (3) Adding modified asphalt and modified fiber to the slurry mixture obtained in step (2), and stirring to obtain the high-performance aging-resistant concrete.

10. The method for preparing high-performance aging-resistant concrete according to claim 9, 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.