Chemical corrosion resistant aluminoferrite cement concrete and preparation method thereof

Abstract

The invention relates to the technical field of building materials, and discloses chemical-corrosion-resistant aluminoferrite cement concrete and a preparation method thereof.The molecular structure of sodium alginate is rich in carboxyl, sodium alginate can generate coordination crosslinking with Ca < 2 + > and Al < 3 + > in blast furnace slag to form hydrogel of a three-dimensional structure, the hydrogel and an original covalent network form a compact dual-network structure, and the chemical-corrosion-resistant aluminoferrite cement concrete is prepared. External ions are not easy to diffuse, and the corrosion resistance of the concrete is enhanced; the organic silicon fluorine epoxy modified acrylic emulsion can form a waterproof layer on the surface of the concrete to prevent erosion factors from entering in a physical barrier manner, so that the corrosion resistance of the concrete is further improved; the cross-linking density of the whole mixed network is also increased through interpenetration and interpenetration of the organic hydrogel and the inorganic filler, the mechanical strength and the anti-permeability performance of the concrete material are further improved through inner doping and outer coating processes, and the concrete material is low in cost, environmentally friendly and easy to industrially produce.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, in particular to chemical corrosion resistant ferroaluminate cement concrete and a preparation method thereof. Background Art

[0002] Concrete is the most widely used and largest-volume civil engineering material today. However, concrete is porous and heterogeneous and is a typical brittle material with defects such as poor toughness and large drying shrinkage. Compared with its compressive strength, concrete is more easily "broken". Currently, concrete buildings and components are often subject to surface corrosion due to various external forces during use. If this situation is not handled in time, the scope of corrosion will continue to expand. In some oceans, saline-alkali lands, groundwater or environments where deicing salt is sprayed on the surface, concrete structures are often corroded and damaged by surrounding harmful ions and have poor resistance to chemical corrosion. At the same time, due to the presence of pores inside the concrete, it is possible for water to penetrate, which in turn causes damage to the concrete interior, resulting in a reduction in the strength of the concrete structure, thereby affecting the life and use of the concrete. Therefore, the development of a concrete that is resistant to chemical corrosion has become a hot topic of current research.

[0003] Ferroaluminate cement is a cement clinker made of ferrous materials, bauxite and silicate, which is calcined to obtain anhydrous calcium sulfoaluminate, dicalcium silicate and calcium aluminate as the main mineral components, and then ground into a suitable amount of limestone and gypsum. It has excellent durability and is a very environmentally friendly building material. However, ferroaluminate cement concrete has a high risk of temperature cracking due to its rapid hydration and concentrated hydration heat release. In addition, although ferroaluminate cement concrete can achieve certain anti-corrosion performance, for specific application environments such as western saline-alkali, oceans or sewage pools in sewage treatment plants, it has higher requirements for the performance of waterproof and anti-corrosion materials, and needs to withstand the erosion of high-salt and high-alkaline environments for a long time to maintain stable performance. The existing concrete often cannot meet the above requirements.

[0004] The currently commonly used alumina-ferrocement has a general bonding strength with old concrete components, and the interface is prone to cracking and leakage. External moisture and harmful corrosive media will enter the interior of the concrete through the cracks, inducing various corrosion damages, which seriously limits its scope of use. The present invention prepares alumina-ferrocement concrete with excellent chemical corrosion resistance by preparing blast furnace slag cementitious materials and organic silicon fluorine epoxy modified acrylic emulsion, and adopts a combination of "internal mixing" and "external coating", thereby significantly improving the mechanical properties and durability of the concrete. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a chemical corrosion resistant aluminoaluminate cement concrete and a preparation method thereof, which significantly improves the corrosion resistance and waterproof and crack resistance of the aluminoaluminate cement concrete.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A chemical corrosion resistant ferroaluminate cement concrete comprises the following components in parts by weight: 320-360 parts of ferroaluminate cement, 150-170 parts of tap water, 1050-1150 parts of coarse aggregate, 700-750 parts of fine aggregate, 70-90 parts of fly ash, 3-8 parts of polycarboxylate high-efficiency water reducing agent, 2-4 parts of early strength agent, 1-5 parts of blast furnace slag cementitious material, 3-15 parts of organosilicon fluoride epoxy modified acrylic emulsion and 10-15 parts of expansion agent.

[0008] The preparation method of blast furnace slag cementitious material is as follows: adding 8-12 mol / L sodium hydroxide solution to commercially available liquid water glass with a modulus of 3.3, mixing and stirring evenly, preparing an alkali activator with a modulus of 1.6 and standing for use; weighing sodium alginate and particle-grade blast furnace slag in a mass ratio of 1: (360-450), adding them to the alkali activator, stirring at room temperature for 5-10 minutes, and obtaining the blast furnace slag cementitious material.

[0009] Preferably, the particle size of the granular blast furnace slag is 0.03-0.05 mm, and its chemical composition includes: 35.4% CaO, 33.2% SiO2, 12.5% ​​Al2O3, 9.0% MgO, 2.4% TiO2, 1.5% Fe2O3 and other substances.

[0010] Preferably, the early strength agent is any one of triethanolamine, water glass or sodium aluminate; and the expansion agent is calcium sulfoaluminate expansion agent.

[0011] Preferably, the coarse aggregate is crushed stone with a particle size of 5-25 mm, and the fine aggregate is quartz sand with a particle size of 0.6-0.9 mm.

[0012] Preferably, the preparation method of the organosilicon-fluorine-epoxy modified acrylic emulsion is:

[0013] Step (1), under nitrogen atmosphere, add bis(dimethyl(vinyl)silyl)amine and ethanol to a reaction flask, stir evenly, add perfluorooctyl bromide and sodium hydride, stir to react, after the reaction is completed, vacuum distillation, column chromatography purification, to obtain an alkenyl organosilicon fluorine monomer. The preparation reaction formula is as follows:

[0014]

[0015] Step (2), under a nitrogen atmosphere, add isopropanol, 1 / 3 of the total mass of methacrylic acid, butyl acrylate, epoxy resin E-44 and alkenyl organosilicon fluorine monomer into a reaction flask, after complete dissolution, add 1 / 3 of the mass of azobisisobutyronitrile, heat to 75-90° C. and react for 20-40 min, add the remaining 2 / 3 of the mass of methacrylic acid, butyl acrylate, epoxy resin E-44 and alkenyl organosilicon fluorine monomer and azobisisobutyronitrile dropwise, continue to react for 2-4 h, cool to 45-55° C., add triethylamine for neutralization, add deionized water for dispersion under high-speed stirring, and obtain an organosilicon fluorine epoxy modified acrylic emulsion.

[0016] Preferably, in step (1), the mass ratio of bis(dimethyl(vinyl)silyl)amine, ethanol, perfluorooctyl bromide and sodium hydride is 1:(15-30):(2.2-3):(0.15-0.25).

[0017] Preferably, in step (1), the reaction temperature is 60-80° C. and the reaction time is 24-48 h.

[0018] Preferably, in step (2), the mass ratio of isopropanol, methacrylic acid, butyl acrylate, epoxy resin E-44, alkenyl organosilicone fluorine monomer, and azobisisobutyronitrile is 100:(9-15):(25-40):(5-10):(3-15):(0.6-1.2).

[0019] Preferably, the preparation method is: pour ferroaluminate cement, coarse aggregate, fine aggregate, fly ash, and blast furnace slag cementitious material into a concrete mixer and dry mix for 50-80 seconds. After mixing evenly, add tap water and early strength agent, mix and stir for 1-2 minutes, then add polycarboxylate water reducer, organosilicon fluorine epoxy modified acrylic emulsion and expansion agent, stir for 2-3 minutes, mix evenly, pour into a standard mold, vibrate compact, and naturally cure after molding to obtain chemical corrosion resistant ferroaluminate cement concrete.

[0020] Preferably, the temperature of natural curing is 20-30°C and the humidity is 90-95%.

[0021] By adopting the above technical solution, the beneficial effects of the present invention are:

[0022] The invention firstly reacts bis(dimethyl(vinyl)silyl)amine and perfluorooctyl bromide under the action of sodium hydride to obtain an olefinic organosilicon fluorine monomer, then polymerizes with methacrylic acid, epoxy resin and the like to obtain an organosilicon fluorine epoxy modified acrylic emulsion, then crosslinks and modifies alkalized blast furnace slag using sodium alginate to obtain a blast furnace slag cementitious material, and finally evenly mixes ferroaluminate cement, blast furnace slag cementitious material, organosilicon fluorine epoxy modified acrylic emulsion and the like to obtain a ferroaluminate cement concrete resistant to chemical corrosion.

[0023] In blast furnace slag cementitious materials, the internal Si-O and Al-O covalent bonds of blast furnace slag are broken under the action of alkaline activators, releasing silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons, which are further polycondensed and reconstructed in alkaline solutions to form a three-dimensional covalent network structure connected by Si-O-Al or Si-O-Si covalent bonds; at the same time, the molecular structure of sodium alginate is rich in carboxyl groups, which can react with Ca in blast furnace slag. 2+ 、Al 3+ Coordination cross-linking is produced to form a hydrogel with a three-dimensional structure. Therefore, the original covalent network and the newly formed coordination cross-linking network play a synergistic role, making the cross-linking network more uniform, enhancing the stability of the gelling molecular structure, thereby forming a dense "double network" structure, making it difficult for external ions to diffuse, and enhancing the corrosion resistance of the concrete; on the other hand, the silicone fluoroepoxy modified acrylic emulsion contains fluorinated groups with good hydrophobic properties and silicone with resistance to chemical solvents, which can form a waterproof layer on the concrete surface, preventing the entry of erosion factors in a physical barrier manner, and further improving the corrosion resistance of the concrete.

[0024] Silicone fluorine epoxy modified acrylic emulsion can form a hydrophobic protective layer on the concrete surface to prevent the expansion of surface cracks; blast furnace slag cementitious materials can increase the anti-seepage performance, thereby preventing the entry of external liquids and the formation of material microcracks, making the internal structure of the concrete stable. The mutual penetration and interpenetration of the organic hydrogel and inorganic filler network also increase the cross-linking density of the entire mixed network. Through the combination of "internal mixing" and "external coating" processes, the material strength, deformation resistance and anti-seepage performance are improved. It can be used in the reinforcement of concrete structures with high requirements on strength and anti-seepage and the repair of water leakage. The raw materials utilize waste fly ash, blast furnace slag, etc., which are low-cost, environmentally friendly and easy to industrialize. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0026] Unless otherwise specified, “parts” in the present invention refer to “parts by weight”.

[0027] The particle size of the granular blast furnace slag is 0.03-0.05mm, and its chemical composition includes: 35.4% CaO, 33.2% SiO2, 12.5% ​​Al2O3, 9.0% MgO, 2.4% TiO2, 1.5% Fe2O3 and other substances.

[0028] Bis(dimethyl(vinyl)silyl)amine, CAS number is 7691-02-3.

[0029] Perfluorooctyl bromide, CAS number is 423-55-2.

[0030] Example 1

[0031] (1) Under a nitrogen atmosphere, 30 parts of bis(dimethyl(vinyl)silyl)amine and 750 parts of ethanol were added to a reaction flask, and after stirring, 72 parts of perfluorooctyl bromide and 11.4 parts of sodium hydride were added. The reaction was carried out at 70° C. for 32 h, and the mixture was distilled under reduced pressure and purified by column chromatography. The mobile phase was ethyl acetate and petroleum ether in a ratio of 1:3 to obtain an alkenyl organosilicon fluorine monomer.

[0032] (2) Under a nitrogen atmosphere, 100 parts of isopropanol, 4 parts of methacrylic acid, 9 parts of butyl acrylate, 2 parts of epoxy resin E-44 and 1 part of alkenyl organosilicon fluorine monomer were added to a reaction flask. After complete dissolution, 0.3 parts of azobisisobutyronitrile were added, the temperature was raised to 85°C for reaction for 30 min, 8 parts of methacrylic acid, 18 parts of butyl acrylate, 4 parts of epoxy resin E-44 and 2 parts of alkenyl organosilicon fluorine monomer and 0.6 parts of azobisisobutyronitrile were added dropwise, the reaction was continued for 3 h, the temperature was lowered to 50°C, triethylamine was added for neutralization, and deionized water was added under high-speed stirring to disperse to obtain an organosilicon fluorine epoxy modified acrylic emulsion.

[0033] (3) adding 10 mol / L sodium hydroxide solution to commercially available liquid water glass with a modulus of 3.3, mixing and stirring uniformly to prepare an alkali activator with a modulus of 1.6, and setting aside for use; weighing 15 parts of sodium alginate and 5700 parts of graded blast furnace slag, adding them to the alkali activator, stirring at room temperature for 8 minutes, and obtaining a blast furnace slag cementitious material.

[0034] (4) 350 parts of ferroaluminate cement, 1100 parts of crushed stone with a particle size of 20 mm, 720 parts of quartz sand with a particle size of 0.8 mm, 70 parts of fly ash, and 1 part of blast furnace slag cementitious material were poured into a concrete mixer and dry mixed for 75 seconds. After mixing evenly, 170 parts of tap water and 3 parts of triethanolamine were added and mixed for 1 minute. Subsequently, 3 parts of polycarboxylic acid water reducer, 3 parts of organosilicon fluorine epoxy modified acrylic emulsion, and 15 parts of calcium sulfoaluminate expansion agent were added and stirred for 3 minutes. After mixing evenly, the mixture was poured into a standard mold, vibrated to compact, and naturally cured after molding. The temperature of natural curing was 25° C. and the humidity was 90%, thereby obtaining chemical corrosion resistant ferroaluminate cement concrete.

[0035] Example 2

[0036] (1) Under a nitrogen atmosphere, 60 parts of bis(dimethyl(vinyl)silyl)amine and 900 parts of ethanol were added to a reaction flask, and after stirring, 132 parts of perfluorooctyl bromide and 9 parts of sodium hydride were added. The reaction was carried out at 80° C. for 24 h, and the mixture was distilled under reduced pressure and purified by column chromatography. The mobile system was ethyl acetate and petroleum ether in a ratio of 1:3 to obtain an alkenyl organosilicon fluorine monomer.

[0037] (2) Under a nitrogen atmosphere, 100 parts of isopropanol, 3 parts of methacrylic acid, 9 parts of butyl acrylate, 2.5 parts of epoxy resin E-44 and 2 parts of alkenyl organosilicon fluorine monomer were added to a reaction flask. After they were completely dissolved, 0.2 parts of azobisisobutyronitrile were added. The temperature was raised to 90°C for reaction for 35 minutes. 6 parts of methacrylic acid, 18 parts of butyl acrylate, 5 parts of epoxy resin E-44 and 4 parts of alkenyl organosilicon fluorine monomer and 0.4 parts of azobisisobutyronitrile were added dropwise. The reaction was continued for 2 hours. The temperature was lowered to 55°C, triethylamine was added for neutralization, and deionized water was added for dispersion under high-speed stirring to obtain an organosilicon fluorine epoxy modified acrylic emulsion.

[0038] (3) adding 8 mol / L sodium hydroxide solution to commercially available liquid water glass with a modulus of 3.3, mixing and stirring uniformly to prepare an alkali activator with a modulus of 1.6, and setting aside for use; weighing 10 parts of sodium alginate and 3600 parts of graded blast furnace slag, adding them to the alkali activator, stirring at room temperature for 5 minutes, and obtaining a blast furnace slag cementitious material.

[0039] (4) 320 parts of ferroaluminate cement, 1050 parts of crushed stone with a particle size of 10 mm, 700 parts of quartz sand with a particle size of 0.6 mm, 80 parts of fly ash, and 3 parts of blast furnace slag cementitious material were poured into a concrete mixer and dry mixed for 50 seconds. After being mixed evenly, 165 parts of tap water and 2 parts of water glass were added and mixed and stirred for 1.5 minutes. Then, 4.5 parts of polycarboxylate water reducer, 6 parts of organosilicon fluorine epoxy modified acrylic emulsion, and 10 parts of calcium sulfoaluminate expansion agent were added and stirred for 2.5 minutes. After being mixed evenly, the mixture was poured into a standard mold, vibrated and compacted, and naturally cured after molding. The temperature of natural curing was 30° C. and the humidity was 95%, thereby obtaining chemical corrosion resistant ferroaluminate cement concrete.

[0040] Example 3

[0041] (1) Under a nitrogen atmosphere, 20 parts of bis(dimethyl(vinyl)silyl)amine and 600 parts of ethanol were added to a reaction flask, and after stirring, 60 parts of perfluorooctyl bromide and 5 parts of sodium hydride were added. The reaction was carried out at 60° C. for 48 h, and the mixture was distilled under reduced pressure and purified by column chromatography. The mobile phase was ethyl acetate and petroleum ether in a ratio of 1:3 to obtain an alkenyl organosilicon fluorine monomer.

[0042] (2) Under a nitrogen atmosphere, 100 parts of isopropanol, 5 parts of methacrylic acid, 13 parts of butyl acrylate, 3 parts of epoxy resin E-44 and 3 parts of alkenyl organosilicon fluorine monomer were added to a reaction flask. After they were completely dissolved, 0.4 parts of azobisisobutyronitrile were added, the temperature was raised to 75°C and the reaction was carried out for 40 minutes. 10 parts of methacrylic acid, 26 parts of butyl acrylate, 6 parts of epoxy resin E-44 and 6 parts of alkenyl organosilicon fluorine monomer and 0.8 parts of azobisisobutyronitrile were added dropwise, the reaction was continued for 4 hours, the temperature was lowered to 45°C, triethylamine was added for neutralization, and deionized water was added under high-speed stirring to disperse to obtain an organosilicon fluorine epoxy modified acrylic emulsion.

[0043] (3) Add 12 mol / L sodium hydroxide solution to commercially available liquid water glass with a modulus of 3.3, mix and stir evenly, prepare an alkali activator with a modulus of 1.6, and set aside for use; weigh 8 parts of sodium alginate and 3150 parts of graded blast furnace slag, add them to the alkali activator, stir at room temperature for 10 minutes, and obtain a blast furnace slag cementitious material.

[0044] (4) 360 parts of ferroaluminate cement, 1150 parts of crushed stone with a particle size of 5 mm, 750 parts of quartz sand with a particle size of 0.9 mm, 85 parts of fly ash, and 3 parts of blast furnace slag cementitious material were poured into a concrete mixer and dry mixed for 80 seconds. After mixing evenly, 160 parts of tap water and 4 parts of sodium aluminate were added and mixed and stirred for 2 minutes. Then, 5.5 parts of polycarboxylic acid water reducer, 9 parts of organosilicon fluorine epoxy modified acrylic emulsion, and 12 parts of calcium sulfoaluminate expansion agent were added and stirred for 2 minutes. After mixing evenly, the mixture was poured into a standard mold, vibrated and compacted, and naturally cured after molding. The temperature of natural curing was 20° C. and the humidity was 90%, thereby obtaining chemical corrosion resistant ferroaluminate cement concrete.

[0045] Example 4

[0046] (1) Under a nitrogen atmosphere, 15 parts of bis(dimethyl(vinyl)silyl)amine and 390 parts of ethanol were added to a reaction flask, and after stirring, 42 parts of perfluorooctyl bromide and 3.3 parts of sodium hydride were added. The reaction was carried out at 75° C. for 35 h, and the mixture was distilled under reduced pressure and purified by column chromatography. The mobile phase was ethyl acetate and petroleum ether in a ratio of 1:3 to obtain an alkenyl organosilicon fluorine monomer.

[0047] (2) Under a nitrogen atmosphere, 100 parts of isopropanol, 3.5 parts of methacrylic acid, 10 parts of butyl acrylate, 2 parts of epoxy resin E-44 and 4 parts of alkenyl organosilicon fluorine monomer were added to a reaction flask. After they were completely dissolved, 0.3 parts of azobisisobutyronitrile were added. The temperature was raised to 90°C for reaction for 35 minutes. 7 parts of methacrylic acid, 20 parts of butyl acrylate, 4 parts of epoxy resin E-44 and 8 parts of alkenyl organosilicon fluorine monomer and 0.6 parts of azobisisobutyronitrile were added dropwise. The reaction was continued for 3 hours. The temperature was lowered to 50°C, triethylamine was added for neutralization, and deionized water was added under high-speed stirring to disperse the organic silicone fluorine epoxy modified acrylic emulsion.

[0048] (3) adding 11 mol / L sodium hydroxide solution to commercially available liquid water glass with a modulus of 3.3, mixing and stirring uniformly to prepare an alkaline activator with a modulus of 1.6, and setting aside for use; weighing 5 parts of sodium alginate and 2100 parts of graded blast furnace slag, adding them to the alkaline activator, stirring at room temperature for 90 minutes, and obtaining a blast furnace slag cementitious material.

[0049] (4) 340 parts of ferroaluminate cement, 1120 parts of crushed stone with a particle size of 25 mm, 730 parts of quartz sand with a particle size of 0.8 mm, 70 parts of fly ash, and 5 parts of blast furnace slag cementitious material were poured into a concrete mixer and dry mixed for 80 seconds. After mixing evenly, 155 parts of tap water and 3.5 parts of triethanolamine were added and mixed and stirred for 1.5 minutes. Subsequently, 7 parts of polycarboxylic acid water reducer, 15 parts of organosilicon fluorine epoxy modified acrylic emulsion, and 14 parts of calcium sulfoaluminate expansion agent were added and stirred for 2 minutes. After mixing evenly, the mixture was poured into a standard mold, vibrated and compacted, and naturally cured after molding. The temperature of natural curing was 25° C. and the humidity was 95%, thereby obtaining chemical corrosion resistant ferroaluminate cement concrete.

[0050] Example 5

[0051] (1) Under a nitrogen atmosphere, 10 parts of bis(dimethyl(vinyl)silyl)amine and 250 parts of ethanol were added to a reaction flask, and after stirring, 26 parts of perfluorooctyl bromide and 2.2 parts of sodium hydride were added. The reaction was carried out at 75° C. for 24 h, and the mixture was distilled under reduced pressure and purified by column chromatography. The mobile phase was ethyl acetate and petroleum ether in a ratio of 1:3 to obtain an alkenyl organosilicon fluorine monomer.

[0052] (2) Under a nitrogen atmosphere, 100 parts of isopropanol, 5 parts of methacrylic acid, 13 parts of butyl acrylate, 3 parts of epoxy resin E-44 and 5 parts of alkenyl organosilicon fluorine monomer were added to a reaction flask. After they were completely dissolved, 0.4 parts of azobisisobutyronitrile were added, the temperature was raised to 85°C and the reaction was carried out for 35 minutes. 10 parts of methacrylic acid, 27 parts of butyl acrylate, 6 parts of epoxy resin E-44 and 10 parts of alkenyl organosilicon fluorine monomer and 0.8 parts of azobisisobutyronitrile were added dropwise, the reaction was continued for 4 hours, the temperature was lowered to 50°C, triethylamine was added for neutralization, and deionized water was added under high-speed stirring to disperse the organic silicone fluorine epoxy modified acrylic emulsion.

[0053] (3) Add 12 mol / L sodium hydroxide solution to commercially available liquid water glass with a modulus of 3.3, mix and stir evenly, prepare an alkali activator with a modulus of 1.6, and set aside for use; weigh 2 parts of sodium alginate and 790 parts of graded blast furnace slag, add them to the alkali activator, stir at room temperature for 6 minutes, and obtain a blast furnace slag cementitious material.

[0054] (4) 350 parts of ferroaluminate cement, 1150 parts of crushed stone with a particle size of 20 mm, 750 parts of quartz sand with a particle size of 0.8 mm, 90 parts of fly ash, and 5 parts of blast furnace slag cementitious material were poured into a concrete mixer and dry mixed for 75 seconds. After mixing evenly, 150 parts of tap water and 4 parts of water glass were added and mixed and stirred for 10 minutes. Then, 8 parts of polycarboxylic acid water reducer, 15 parts of organosilicon fluorine epoxy modified acrylic emulsion and 1.5 parts of calcium sulfoaluminate expansion agent were added and stirred for 15 minutes. After mixing evenly, the mixture was poured into a standard mold, vibrated and compacted, and naturally cured after molding. The temperature of natural curing was 25° C. and the humidity was 95%, thereby obtaining chemical corrosion resistant ferroaluminate cement concrete.

[0055] Comparative Example 1

[0056] 350 parts of ferroaluminate cement, 1100 parts of crushed stone with a particle size of 20 mm, 720 parts of quartz sand with a particle size of 0.8 mm, 70 parts of fly ash and 1 part of blast furnace slag are poured into a concrete mixer and dry mixed for 75 seconds. After mixing evenly, 170 parts of tap water and 3 parts of triethanolamine are added and mixed and stirred for 1 minute. Subsequently, 3 parts of polycarboxylic acid water reducer, 3 parts of organosilicon fluorine epoxy modified acrylic emulsion and 15 parts of calcium sulfoaluminate expansion agent are added and stirred for 3 minutes. After mixing evenly, the mixture is poured into a standard mold, vibrated to compact, and naturally cured after molding. The temperature of natural curing is 25°C and the humidity is 90% to obtain ferroaluminate cement concrete.

[0057] Comparative Example 2

[0058] 350 parts of ferroaluminate cement, 1100 parts of crushed stone with a particle size of 20 mm, 720 parts of quartz sand with a particle size of 0.8 mm, 70 parts of fly ash and 1 part of blast furnace slag are poured into a concrete mixer and dry mixed for 75 seconds. After mixing evenly, 170 parts of tap water and 3 parts of triethanolamine are added and mixed and stirred for 1 minute. Then, 3 parts of polycarboxylate water reducer and 15 parts of calcium sulfoaluminate expansion agent are added and stirred for 3 minutes. After mixing evenly, the mixture is poured into a standard mold, vibrated to compact, and naturally cured after molding. The temperature of natural curing is 25°C and the humidity is 90% to obtain ferroaluminate cement concrete.

[0059] Comparative Example 3

[0060] 350 parts of ferroaluminate cement, 1100 parts of crushed stone with a particle size of 20 mm, 720 parts of quartz sand with a particle size of 0.8 mm, and 70 parts of fly ash are poured into a concrete mixer and dry mixed for 75 seconds. After mixing evenly, 170 parts of tap water and 3 parts of triethanolamine are added, mixed and stirred for 1 minute, and then 3 parts of polycarboxylic acid water reducer and 15 parts of calcium sulfoaluminate expansion agent are added, stirred for 3 minutes, and after mixing evenly, poured into a standard mold, vibrated to compact, and naturally cured after molding. The temperature of natural curing is 25°C and the humidity is 90% to obtain ferroaluminate cement concrete.

[0061] Concrete expansion rate test: concrete with a curing age of 28 days was prepared into a sample with a size of 100mm×100mm×515mm, and placed in a magnesium sulfate solution with a sulfate concentration of 6.22 parts / L to test the expansion rate of the concrete in the sulfate solution.

[0062] Chloride ion diffusion coefficient determination: The concrete with curing age of 28 days was prepared into The sample was placed in a 4 mol / L sodium chloride solution, and then the sample was vacuum treated for water retention. The chloride ion diffusion coefficient of concrete was tested using the chloride ion diffusion coefficient determination method.

[0063] Table 1 Corrosion resistance test

[0064]

[0065]

[0066] The expansion rate of concrete against sulfate erosion is directly related to the durability and stability of concrete. When concrete is exposed to an environment containing sulfate, sulfate ions will penetrate into the concrete and react chemically with certain components in the concrete, causing the concrete performance to gradually deteriorate. Therefore, the smaller the expansion rate, the better. In concrete, the smaller the chloride ion diffusion coefficient, the slower the diffusion rate of chloride ions in the concrete, which means that the concrete has a stronger ability to resist chloride ion erosion, thereby better protecting internal structures such as steel bars from corrosion and extending the service life of the concrete structure.

[0067] From the test results in the above table, it can be seen that with the increase of the content of blast furnace slag cementitious material and organosilicon fluorine epoxy modified acrylic emulsion in concrete, the corrosion resistance of ferroaluminate cement concrete is gradually enhanced. The expansion rate of Example 5 in sulfate solution is only 0.015%, and the chloride ion diffusion coefficient is 1.32×10 -12 m 2 / s, has good chemical corrosion resistance; this is because on the one hand, the internal Si-O and Al-O covalent bonds of blast furnace slag in blast furnace slag cementitious materials are broken under the action of alkaline activators, releasing silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons, which are further condensed and reconstructed in alkaline solutions to form a three-dimensional covalent network structure connected by Si-O-Al or Si-O-Si covalent bonds; at the same time, the molecular structure of sodium alginate is rich in carboxyl groups, which can react with Ca in blast furnace slag. 2+ 、Al 3+Coordination cross-linking is produced to form a hydrogel with a three-dimensional structure. Therefore, the original covalent network and the newly formed coordination cross-linking network play a synergistic role, making the cross-linking network more uniform, enhancing the stability of the gelling molecular structure, thereby forming a dense "double network" structure, making it difficult for external ions to diffuse, and enhancing the corrosion resistance of the concrete; on the other hand, the silicone fluoroepoxy modified acrylic emulsion contains fluorinated groups with good hydrophobic properties and silicone with resistance to chemical solvents, which can form a waterproof layer on the concrete surface, preventing the entry of erosion factors in a physical barrier manner, and further improving the corrosion resistance of the concrete.

[0068] The blast furnace slag in Comparative Example 1 has not been modified with sodium alginate, and can only be used as a mineral admixture to fill the voids in the concrete without forming a cross-linked network structure; in Comparative Example 2, no silicone-fluorinated epoxy-modified acrylic emulsion is added, and the concrete surface cannot be effectively filled; Comparative Example 3 does not contain blast furnace slag cementitious materials and silicone-fluorinated epoxy-modified acrylic emulsion, and has the worst chemical corrosion resistance.

[0069] Compressive strength: The test was carried out with reference to GB / T 50081-2019 "Standard for Test Methods for Physical and Mechanical Properties of Concrete", the curing age was 28 days, the sample size was 150mm×150mm×150mm, and the concrete pressure testing machine had a given loading rate of 0.8MPa / s.

[0070] Water penetration resistance test: Referring to GB / T 50082-2009 "Standard for test methods for long-term performance and durability of ordinary concrete", the water penetration height method is used to test the water penetration resistance of concrete. The concrete with a curing age of 28 days is made into a truncated cone with an upper inner diameter of 175mm, a lower inner diameter of 185mm, and a height of 250mm, and placed in a concrete permeameter for water penetration resistance test.

[0071] Table 2 Concrete performance test

[0072] Compressive strength(MPa) Water seepage height (cm) Example 1 65.3 12.5 Example 2 73.5 10.8 Example 3 80.2 8.3 Example 4 82.3 7.5 Example 5 84.1 7.4 Comparative Example 1 53.8 13.9 Comparative Example 2 45.0 16.1 Comparative Example 3 32.4 18.0

[0073] Silicone fluorine epoxy modified acrylic emulsion can form a hydrophobic protective layer on the concrete surface to prevent the expansion of surface cracks; blast furnace slag cementitious materials can increase the anti-seepage performance, thereby preventing the entry of external liquids and the formation of material microcracks, making the internal structure of the concrete stable. The mutual penetration and interpenetration of the organic hydrogel and inorganic filler network also increase the cross-linking density of the entire mixed network. Through the "internal mixing" and "external coating" processes, the material strength, deformation resistance and anti-seepage performance are improved. It can be used in the fields of ocean, saline-alkali and military emergency repair and construction in extreme environments with high requirements for strength and corrosion resistance. The raw materials used are waste fly ash, blast furnace slag, etc., which are low-cost, environmentally friendly and easy to industrialize.

[0074] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application; the methods used in the present application are conventional methods unless otherwise specified.

Claims

1. A chemical corrosion resistant ferroaluminate cement concrete, characterized in that: The alumina-ferrocement concrete comprises the following components in parts by weight: 320-360 parts of alumina-ferrocement, 150-170 parts of tap water, 1050-1150 parts of coarse aggregate, 700-750 parts of fine aggregate, 70-90 parts of fly ash, 3-8 parts of polycarboxylate high-efficiency water reducing agent, 2-4 parts of early strength agent, 1-5 parts of blast furnace slag cementitious material, 3-15 parts of organosilicon fluoride epoxy modified acrylic emulsion and 10-15 parts of expansion agent; The preparation method of the blast furnace slag cementitious material comprises the following steps: adding 8-12 mol / L sodium hydroxide solution to commercially available liquid water glass with a modulus of 3.3, mixing and stirring evenly, preparing an alkali activator with a modulus of 1.6 and allowing the alkali activator to stand for use; weighing sodium alginate and particle-grade blast furnace slag in a mass ratio of 1:(360-450), adding the mixture to the alkali activator, and stirring at room temperature for 5-10 minutes to obtain the blast furnace slag cementitious material.

2. The chemical corrosion resistant ferroaluminate cement concrete according to claim 1, characterized in that: The particle size of the graded blast furnace slag is 0.03-0.05 mm, and its chemical composition includes: 35.4% CaO, 33.2% SiO2, 12.5% ​​Al2O3, 9.0% MgO, 2.4% TiO2, 1.5% Fe2O3 and other substances.

3. The chemical corrosion resistant ferroaluminate cement concrete according to claim 1, characterized in that: The early strength agent is any one of triethanolamine, water glass or sodium aluminate; the expansion agent is calcium sulphoaluminate expansion agent.

4. The chemical corrosion resistant ferroaluminate cement concrete according to claim 1, characterized in that: The coarse aggregate is crushed stone with a particle size of 5-25 mm, and the fine aggregate is quartz sand with a particle size of 0.6-0.9 mm.

5. The chemical corrosion resistant ferroaluminate cement concrete according to claim 1, characterized in that: The preparation method of the organosilicon-fluorine epoxy modified acrylic emulsion is: Step (1), under a nitrogen atmosphere, add bis(dimethyl(vinyl)silyl)amine and ethanol to a reaction flask, stir evenly, add perfluorooctyl bromide and sodium hydride, stir to react, and after the reaction is completed, perform vacuum distillation and column chromatography purification to obtain an alkenyl organosilicone fluorine monomer; Step (2), under a nitrogen atmosphere, add isopropanol, 1 / 3 of the total mass of methacrylic acid, butyl acrylate, epoxy resin E-44 and alkenyl organosilicon fluorine monomer into a reaction flask, after complete dissolution, add 1 / 3 of the mass of azobisisobutyronitrile, heat to 75-90° C. and react for 20-40 min, add the remaining 2 / 3 of the mass of methacrylic acid, butyl acrylate, epoxy resin E-44 and alkenyl organosilicon fluorine monomer and azobisisobutyronitrile dropwise, continue to react for 2-4 h, cool to 45-55° C., add triethylamine for neutralization, add deionized water for dispersion under high-speed stirring, and obtain an organosilicon fluorine epoxy modified acrylic emulsion.

6. The chemical corrosion resistant ferroaluminate cement concrete according to claim 5, characterized in that: In the step (1), the mass ratio of bis(dimethyl(vinyl)silyl)amine, ethanol, perfluorooctyl bromide and sodium hydride is 1:(15-30):(2.2-3):(0.15-0.25).

7. The chemical corrosion resistant ferroaluminate cement concrete according to claim 5, characterized in that: In the step (1), the reaction temperature is 60-80° C. and the reaction time is 24-48 h.

8. The chemical corrosion resistant ferroaluminate cement concrete according to claim 5, characterized in that: In the step (2), the mass ratio of isopropyl alcohol, methacrylic acid, butyl acrylate, epoxy resin E-44, alkenyl organosilicone fluorine monomer, and azobisisobutyronitrile is 100:(9-15):(25-40):(5-10):(3-15):(0.6-1.2).

9. A method for preparing chemical corrosion resistant ferroaluminate cement concrete according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: pouring ferroaluminate cement, coarse aggregate, fine aggregate, fly ash and blast furnace slag cementitious material into a concrete mixer and dry mixing for 50-80 seconds, adding tap water and an early strength agent after mixing evenly, mixing and stirring for 1-2 minutes, then adding a polycarboxylate water reducer, an organosilicon fluorine epoxy modified acrylic emulsion and an expansion agent, stirring for 2-3 minutes, pouring into a standard mold after mixing evenly, vibrating and compacting, and naturally curing after forming to obtain ferroaluminate cement concrete resistant to chemical corrosion.

10. The method for preparing chemical corrosion resistant ferroaluminate cement concrete according to claim 9, characterized in that: The temperature of the natural curing is 20-30° C., and the humidity is 90-95%.

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