High-durability aluminoferrite cement-based self-compacting concrete and preparation method thereof

Abstract

The invention discloses high-durability aluminoferrite cement-based self-compacting concrete and a preparation method thereof, and belongs to the technical field of maritime work concrete.The high-durability aluminoferrite cement-based self-compacting concrete is prepared from 60-70 parts of freeze-thaw-resistant clinker, 20-30 parts of chlorine-resistant steel slag micro powder, 8-13 parts of high-strength corrosion-resistant desulfurized gypsum, 0.8-1.3 parts of an additive, 88-124 parts of coarse aggregate, 76-116 parts of fine aggregate and 22-38 parts of water. According to the freeze-thaw-resistant clinker, the freezing resistance of concrete is enhanced by reducing the porosity and the pore diameter. The desulfurized gypsum subjected to crystal form regulation and control enhances the sulfate corrosion resistance of the concrete. The PAA / QCS-CA hydrogel enables the early strength of the concrete to be rapidly increased, accelerates the construction progress, and ensures that the airport pavement can be rapidly put into use. The high-strength corrosion-resistant desulfurized gypsum can promote early hydration of the cement and improve the early strength.

Description

Technical Field

[0001] The present invention relates to the technical field of marine engineering concrete, and particularly relates to a high-durability ferroaluminate cement-based self-compacting concrete and a preparation method thereof. Background Art

[0002] In the construction and maintenance of seaside airports or military bases, airport pavements face extremely harsh service environments. The huge loads generated by aircraft takeoffs and landings act repeatedly on the pavement, requiring the pavement concrete to have high strength and high durability. At the same time, the unique climate and geological conditions in coastal areas cause airport pavements to be continuously eroded by seawater and attacked by salt spray. In particular, during the low-temperature period in winter, the pavement is frequently affected by freeze-thaw cycles. The water in the pores inside the concrete freezes and expands when it gets cold, and then melts and shrinks. Repeatedly like this, microcracks are generated in the concrete structure. At the same time, the salts in seawater continuously crystallize and precipitate in the pores of the pavement concrete, with volume expansion, further exacerbating the damage to the internal structure of the concrete, resulting in serious diseases such as cracks, spalling, and strength reduction on the pavement.

[0003] Workability and compactness are the prerequisite conditions for ensuring the strength and durability of concrete. The pavements of airports or military bases have extremely high requirements for the compactness of concrete. Ordinary concrete usually needs to use internal vibrators or screed vibrators to discharge the gas in the concrete mixture, so as to improve the compactness of the concrete. Self-compacting concrete is a kind of concrete that can flow and compact under its own gravity, can be completely filled even in the presence of dense steel bars, and can obtain good homogeneity at the same time, and does not require additional vibration. Ferroaluminate cement has the characteristics of rapid hardening and early strength, good volume stability, and no chemical corrosion. It has been applied in real sea projects in complex environments such as the ocean for more than 40 years. On-site core sampling shows that the concrete structure is intact and dense, without corrosion damage, and the strength does not decrease but increases instead. Engineering practice shows that ferroaluminate cement is an effective measure to solve the marine corrosion of concrete structures. Therefore, developing high-durability ferroaluminate cement-based self-compacting concrete for the construction and maintenance of seaside airports or military bases has very important engineering application value and social significance. Summary of the Invention

[0004] In view of the above-mentioned drawbacks existing in the prior art, the present invention provides a high-durability ferroaluminate cement-based self-compacting concrete and a preparation method thereof.

[0005] To achieve the above object, the present invention is realized through the following technical solutions:

[0006] A high-durability ferroaluminate cement-based self-compacting concrete, by weight, comprises the following components:

[0007] 60-70 parts of freeze-thaw resistant clinker;

[0008] 20 - 30 parts of chlorine - resistant steel slag powder;

[0009] 8 - 13 parts of high - strength and corrosion - resistant desulfurized gypsum;

[0010] 0.8 - 1.3 parts of admixture;

[0011] 88 - 124 parts of coarse aggregate;

[0012] 76 - 116 parts of fine aggregate;

[0013] 22 - 38 parts of water;

[0014] The freeze - thaw resistant clinker is obtained by wind - selection and impurity removal of calcareous, aluminous and ferrous raw materials, grinding and modification with spodumene and potassium sulfate powder, stirring and homogenization, and high - temperature calcination;

[0015] The chlorine - resistant steel slag powder is obtained by composite acid etching and aging;

[0016] The high - strength and corrosion - resistant desulfurized gypsum is obtained by composite modification with ferrous sulfate and borax, stirring, sieving and homogenization, and surface compounding with nano - zinc oxide.

[0017] Furthermore, the admixture includes a viscosity - increasing and water - reducing agent, a thickening agent and an air - entraining agent with a mass ratio of 1 - 1.5:0.05 - 0.1:0.01 - 0.05;

[0018] The viscosity - increasing and water - reducing agent is obtained by swelling HPMC and then shearing with polycarboxylic acid mother liquor, PAA / QCS - CA hydrogel and nano - silica by heating.

[0019] A preparation method of the high - durability ferroaluminate cement - based self - compacting concrete as described above, comprising the following steps:

[0020] Step 1: Chlorine - resistance modification of steel slag powder;

[0021] A1. Citric acid - malic acid composite acid etching;

[0022] Soak the steel slag with a mixed solution of citric acid and malic acid to obtain acid - etched steel slag;

[0023] A2. Ion implantation strengthening;

[0024] Use an ion implantation device to implant lithium ions into the acid - etched steel slag to obtain strengthened steel slag;

[0025] A3. High - temperature roasting - airflow pulverization and homogenization;

[0026] Roast the A2 strengthened steel slag and pulverize it to obtain homogenized steel slag;

[0027] A4. Surface coating with polymethyltriethoxysilane;

[0028] Completely immerse A3 homogenized steel slag in an ethanol solution of polymethyltriethoxysilane, stir, and then dry it.

[0029] A5. Classification - aging treatment;

[0030] Remove coarse particles and fine powder from the steel slag coated in A4 through an air classifier, and conduct aging treatment to obtain anti-chlorine steel slag micropowder.

[0031] Step Two: Crystal form regulation of desulfurized gypsum;

[0032] B1. High-temperature calcination - water washing for impurity removal;

[0033] Calcine the desulfurized gypsum, and wash it with water to remove impurities such as soluble salts and unreacted limestone.

[0034] B2. Composite modification with ferrous sulfate - borax;

[0035] Add ferrous sulfate and borax to the desulfurized gypsum after impurity removal in B1 and grind them together to obtain crystal form regulated gypsum.

[0036] B3. Stirring - sieving for homogenization;

[0037] Stir and sieve the crystal form regulated gypsum in B2 to obtain homogenized desulfurized gypsum.

[0038] B4. Surface compounding with nano-zinc oxide;

[0039] Ultrasonically disperse the homogenized desulfurized gypsum in B3 and nano-zinc oxide in absolute ethanol, and dry it to obtain high-strength and corrosion-resistant desulfurized gypsum.

[0040] Step Three: Frost resistance modification of ferroaluminate cement;

[0041] C1. Pneumatic separation for impurity removal;

[0042] Remove light impurities and dust from the raw material of ferroaluminate cement through a pneumatic separation device.

[0043] C2. Synergistic modification with spodumene - potassium sulfate;

[0044] Add spodumene and potassium sulfate to the raw material and grind them to obtain modified cement raw material.

[0045] C3. Stir to obtain homogenized raw material;

[0046] C4. Calcination;

[0047] Calcine the homogenized raw material in C3 to obtain freeze-thaw resistant clinker.

[0048] Step Four: Gradient compounding of water reducing agents;

[0049] D1. Swelling; Add HPMC to warm water and stir until it completely dissolves to form a transparent colloid.

[0050] D2. Compound; sequentially add the polycarboxylic acid mother liquor and the pre-swollen PAA / QCS-CA hydrogel aqueous solution, stir, add the nano-silica pre-dispersed in the ethanol solution, and continue to stir until the particles are uniform;

[0051] D3. Crosslink; increase the temperature and perform high-speed shearing to obtain a viscosity-increasing water reducing agent;

[0052] Step Five, step-by-step compounding;

[0053] E1. Premixing of cementitious materials;

[0054] Mix the freeze-thaw resistant clinker, chloride-resistant steel slag micro-powder and high-strength corrosion-resistant desulfurized gypsum to obtain a cementitious material;

[0055] E2. Addition and mixing of admixtures;

[0056] Add admixtures to the cementitious material and stir evenly;

[0057] E3. Addition and stirring of aggregates;

[0058] Add coarse and fine aggregates to the viscosity-increasing cementitious material and uniformly mix to obtain a concrete mixture;

[0059] E4. Addition of water and final stirring;

[0060] Add water to the concrete mixture to obtain high-durability ferroaluminate cement-based self-compacting concrete.

[0061] Furthermore, step one is specifically: A1. Use a mixed solution of 4-7% citric acid and 2-4% malic acid to soak the steel slag at 45-65°C for 2-3 hours to obtain acid-etched steel slag;

[0062] A2. Using an ion implantation device, inject lithium ions at a dose of - ions / into the acid-etched steel slag to obtain strengthened steel slag;

[0063] A3. Roast the A2 strengthened steel slag at 600-800°C for 1-2 hours; crush it through an air flow mill to obtain homogenized steel slag, and control the particle size D50 after crushing to be 15-25 μm;

[0064] A4. Completely immerse the A3 homogenized steel slag in an ethanol solution of 0.6-1.2% polymethyltriethoxysilane, stir for 1.5-2.5 hours and then dry;

[0065] A5. Remove the coarse particles and fine powder of the A4-coated steel slag through an air classifier with a classification particle size of 20-35 μm, and place it in an environment with a relative humidity of 60%-80% and a temperature of 20-30°C for 3-5 days for aging treatment to obtain chloride-resistant steel slag micro-powder.

[0066] Further, step two is specifically as follows: B1. Calcinate the desulfurized gypsum at 150 - 200 °C for 1 - 2 h, and wash it with water to remove soluble salts and impurities such as unreacted limestone;

[0067] B2. Add 0.8 - 1.5% ferrous sulfate and 0.2 - 0.4% borax to the desulfurized gypsum after impurity removal in B1, and grind them together to obtain crystal form - regulated gypsum;

[0068] B3. Put the crystal form - regulated gypsum in B2 into a stirring device, stir it at a speed of 150 - 250 r / min for 20 - 30 min, and sieve it through a 100 - 200 - mesh sieve to obtain homogenized desulfurized gypsum;

[0069] B4. Ultrasonically disperse the homogenized desulfurized gypsum in B3 and 0.3 - 0.5% nano - zinc oxide with a particle size of 30 - 40 nm in absolute ethanol for 40 - 70 min, and obtain composite gypsum after drying;

[0070] Further, step three is specifically as follows: C1. Remove light impurities and dust from the raw material of ferroaluminate cement through a pneumatic separation device;

[0071] C2. Add 3 - 5% spodumene and 0.6 - 1.1% potassium sulfate to the raw material and grind it to obtain modified cement raw material;

[0072] C3. Put the strengthened raw material in C2 into a planetary stirring device, stir it at a speed of 250 - 350 r / min for 30 - 45 min to obtain homogenized raw material;

[0073] C4. Calcinate the homogenized raw material in C3 at 1300 - 1400 °C to obtain freeze - thaw resistant clinker.

[0074] Further, step four is specifically as follows: D1. Add HPMC to warm water at 25 - 35 °C, stir it at a stirring speed of 60 - 100 r / min for 20 - 40 min until it is completely dissolved to form a transparent colloid;

[0075] D2. Sequentially add polycarboxylic acid mother liquor and the pre - swollen PAA / QCS - CA hydrogel aqueous solution, stir it at a speed of 150 - 250 r / min for 25 - 35 min, add nano - silica pre - dispersed in ethanol solution, and continue to stir until the particles are uniform;

[0076] D3. Heat up to 45 - 60 °C, and perform high - speed shearing at 250 - 350 r / min for 15 - 25 min to obtain a thickening and water - reducing agent.

[0077] Further, Step 5 is specifically as follows: E1. Mix the freeze-thaw resistant clinker, anti-chlorine steel slag powder, and high-strength corrosion-resistant desulfurized gypsum to obtain a cementitious material, and stir at a speed of 100-150 r / min for 5-10 min;

[0078] E2. Add an admixture to the cementitious material, stir at a speed of 150-200 r / min, and stir for 8-12 min;

[0079] E3. Add coarse and fine aggregates to the thickened cementitious material and uniformly mix to obtain a concrete mixture;

[0080] E4. Slowly add water to the concrete mixture to obtain a high-durability ferroaluminate cement-based self-compacting concrete.

[0081] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0082] 1. By incorporating spodumene, the present invention can refine the raw material particles, increase the specific surface area, and enhance the reaction activity during grinding modification. Potassium sulfate can reduce the negative impact of impurities in the raw materials. The synergistic effect of the two enables the raw materials to fully react and recombine during the subsequent calcination process, improving the compactness of the cement hydration products, reducing the porosity and pore size, and enhancing the frost resistance of the concrete.

[0083] 2. After crystal form regulation, the desulfurized gypsum in the present invention has regular crystal morphology and uniform particle distribution. During the cement hydration process, ettringite is generated to fill the pores and form a dense protective layer, preventing the intrusion of external sulfate ions, thereby improving the sulfate erosion resistance of the concrete, effectively resisting the erosion of seawater sulfate ions, and preventing the damage and diseases of the internal structure of the concrete. The PAA / QCS-CA hydrogel has high water retention and water absorption, can provide a good wet environment for the hydration of desulfurized gypsum, and promote its hydration reaction. The active groups of its molecular chain can interact with the hydration products of desulfurized gypsum to form a denser protective layer, enhancing the sulfate erosion resistance performance of the concrete. The compounding of the two has a synergistic effect, providing more reliable protection for airport pavements and extending the service life.

[0084] 3. The desulfurized gypsum after crystal form regulation has better particle gradation and fluidity in the concrete. Its regular crystal morphology and uniform particle size distribution improve the rheological properties of the concrete, reduce the stirring resistance, make the slurry more uniform, and improve the fluidity and stability. During pouring, the concrete can smoothly fill complex forms and areas with dense steel bars, not only improving the construction operability and quality, but also reducing the risk of diseases caused by non-compaction.

[0085] 4. The unique molecular structure of the PAA / QCS-CA hydrogel can accelerate the cement hydration reaction. Its active groups interact with the cement hydration products, promoting the early hydration of cement, generating a large amount of hydration products, and rapidly enhancing the strength of concrete. At the same time, it can also seal the capillary pores, reduce water evaporation, provide a good humidity environment for continuous hydration, enable the rapid growth of the early strength of concrete, speed up the construction progress, and ensure the rapid commissioning of the airport pavement. The high-strength and corrosion-resistant desulfurized gypsum can promote the early hydration of cement and improve the early strength; the PAA / QCS-CA hydrogel optimizes the microstructure of concrete and enhances the density and strength development rate. The two are compounded and act synergistically, significantly improving the rapid hardening and early strength performance of concrete, ensuring that the pavement can withstand the aircraft takeoff and landing loads, and providing a solid foundation for airport operation. Detailed implementation mode

[0086] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, rather than all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0087] Embodiment 1: This embodiment provides a preparation method for a high-durability ferroaluminate cement-based self-compacting concrete, including the following steps:

[0088] Step 1. Chloride resistance modification of steel slag powder;

[0089] A1. Citric acid-malic acid composite acid etching;

[0090] Soak the steel slag in a mixed solution of 7% citric acid and 4% malic acid (pH = 3.8) at 65 °C for 3 h (liquid-solid ratio 5.5:1) to obtain acid-etched steel slag. The chelating effect of citric acid accelerates the dissolution of iron rust, and the hydroxyl group of malic acid enhances the affinity with the steel slag surface. The two work together to increase the exposure rate of active sites on the steel slag surface;

[0091] A2. Aging treatment;

[0092] Carry out aging treatment in an environment with a relative humidity of 80% and a temperature of 30 °C for 5 days to make the performance of the steel slag more stable, and obtain chloride-resistant steel slag powder;

[0093] Step 2. Crystal form regulation of desulfurized gypsum;

[0094] B1. High-temperature calcination - water washing and impurity removal;

[0095] Calcine the desulfurized gypsum at 200 °C for 2 h to remove part of the crystal water and volatile impurities, and wash with water to remove soluble salts and unreacted limestone and other impurities to improve the purity of the desulfurized gypsum;

[0096] B2. Composite modification with ferrous sulfate - borax;

[0097] Add 1.5% ferrous sulfate and 0.4% borax to the desulfurized gypsum after impurity removal in B1 and grind them together to obtain crystal form - regulated gypsum. The ferrous ions in ferrous sulfate can participate in the hydration reaction of gypsum and change the crystal growth environment; borax can delay the hydration rate of gypsum and promote the directional growth of AFt crystals;

[0098] B3. Stirring - sieving homogenization;

[0099] Put the crystal form - regulated gypsum in B2 into a stirring device and stir at a speed of 250 r / min for 30 min, then sieve it through a 200 - mesh sieve to obtain homogenized desulfurized gypsum, removing large - particle agglomerates and ensuring the uniformity of gypsum particles;

[0100] B4. Surface compounding with nano - zinc oxide;

[0101] Ultrasonically disperse the homogenized desulfurized gypsum in B3 and 0.5% nano - zinc oxide (particle size 40 nm) in absolute ethanol (power 350 W) for 70 min, and then dry to obtain composite gypsum; nano - zinc oxide can fill the pores of gypsum, improving its impermeability and antibacterial properties; obtain high - strength and corrosion - resistant desulfurized gypsum;

[0102] Step 3. Frost - resistance modification of ferroaluminate cement;

[0103] C1. Pneumatic separation for impurity removal;

[0104] Remove light impurities and dust from the raw material of ferroaluminate cement (calcareous raw material, aluminous raw material and ferrous raw material with a mass ratio of 5:2:3) through a pneumatic separation device;

[0105] C2. Synergistic modification with spodumene - potassium sulfate;

[0106] Add 5% spodumene (lithium ions generated by the decomposition of spodumene during calcination can participate in the hydration reaction and change the structure of hydration products) and 1.1% potassium sulfate (potassium sulfate can promote the formation of ettringite and improve the frost - resistance performance) to the raw material and grind to obtain modified cement raw material;

[0107] C3. Stirring homogenization;

[0108] Put the modified cement raw material in C2 into a planetary stirring device and stir at a speed of 350 r / min for 45 min to obtain homogenized raw material, making the raw material and additives fully mixed evenly and ensuring the consistency of performance in each part;

[0109] C4. Calcination;

[0110] Calcine the C3 homogeneous raw material at 1400 °C to obtain freeze-thaw resistant clinker; make the internal structure of the clinker more dense and improve its freeze-thaw cycle resistance;

[0111] Step Four: Gradient compounding of water reducing agents;

[0112] D1. Swelling: Add HPMC (hydroxypropyl methyl cellulose ether) to warm water at 35 °C and stir at a speed of 100 r / min for 40 min until it is completely dissolved to form a transparent colloid;

[0113] D2. Compound: Sequentially add polycarboxylic acid mother liquor and pre-swollen PAA / QCS-CA hydrogel aqueous solution, stir at a speed of 250 r / min for 35 min, add nano-silica pre-dispersed in ethanol solution, and continue to stir until the particles are uniform;

[0114] The PAA / QCS-CA hydrogel is selected from Chen Runlan, Liang Ziyi, Wang Xinyue, etc. Preparation and properties of acrylic acid / chitosan quaternary ammonium salt-citric acid tough wet adhesion hydrogel [J]. Journal of Fujian Normal University (Natural Science Edition), 2024, 40(06): 1-8.

[0115] The ratio of the polycarboxylic acid mother liquor, PAA / QCS-CA hydrogel, HPMC and nano-silica is 1.5:0.1:0.3:0.2;

[0116] D3. Crosslinking: Raise the temperature to 60 °C and carry out high-speed shearing at 350 r / min for 25 min to obtain a viscosity-increasing water reducing agent;

[0117] Step Five: Stepwise compounding;

[0118] E1. Premixing of cementitious materials;

[0119] Mix 70 parts of freeze-thaw resistant clinker, 30 parts of chloride-resistant steel slag micro powder and 13 parts of high-strength and corrosion-resistant desulfurized gypsum to obtain a cementitious material, and stir at a speed of 150 r / min for 10 min to make the three cementitious materials fully mixed and uniform. During the stirring process, the active components of the chloride-resistant steel slag micro powder and the high-strength and corrosion-resistant desulfurized gypsum interact with the freeze-thaw resistant clinker to form a preliminary hydration product skeleton, providing a basis for subsequent compounding;

[0120] E2. Addition and mixing of admixtures;

[0121] Add 1.3 parts of admixtures to the cementitious material, with a stirring speed of 200 r / min and a stirring time of 12 min to ensure that the admixtures are uniformly dispersed in the cementitious material to obtain a viscosity-increasing cementitious material; the admixtures include a viscosity-increasing water reducing agent, a thickening agent and an air-entraining agent with a mass ratio of 1.5:0.1:0.05;

[0122] Thickening agent: Hydroxypropyl methylcellulose is used to increase the viscosity of the concrete, improve its segregation resistance and self-compacting property;

[0123] E3. Aggregate addition and mixing;

[0124] Coarse and fine aggregates are added to the thickening cementitious material;

[0125] Coarse aggregate: Crushed stones with a particle size of 20 mm are selected, and the mud content does not exceed 1%;

[0126] Fine aggregate: Medium sand with a fineness modulus of 3.0 is used, and the mud content does not exceed 3%;

[0127] 124 parts of coarse aggregate are added and stirred at a speed of 220 r / min for 5 min, then 116 parts of fine aggregate are added and stirring continues for 8 min to uniformly mix the coarse and fine aggregates with the cementitious material, obtaining a concrete mixture;

[0128] E4. Water addition and final mixing;

[0129] 38 parts of water are slowly added to the concrete mixture to obtain high-durability ferroaluminate cement-based self-compacting concrete. During the water addition process, the stirring speed is maintained at 250 r / min and the stirring time is 15 min to allow the water to fully participate in the hydration reaction and ensure that the fluidity, cohesiveness and water retention of the concrete reach the best state.

[0130] Example 2: This example provides a preparation method of high-durability ferroaluminate cement-based self-compacting concrete, including the following steps:

[0131] Step 1. Chloride resistance modification of steel slag powder;

[0132] A1. Citric acid-malic acid composite acid etching;

[0133] A mixed solution of 4% citric acid and 2% malic acid (pH = 2.8) is used to soak the steel slag at 45 °C for 2 h (liquid-solid ratio 3.5:1) to obtain acid-etched steel slag. The chelating effect of citric acid accelerates the dissolution of iron rust, and the hydroxyl group of malic acid enhances the affinity with the steel slag surface. The two work together to increase the exposure rate of active sites on the steel slag surface;

[0134] A2. Aging treatment;

[0135] The steel slag is placed in an environment with a relative humidity of 60% and a temperature of 20 °C for 3 days for aging treatment to make the steel slag performance more stable, obtaining chloride-resistant steel slag powder;

[0136] Step 2. Crystal form regulation of desulfurized gypsum;

[0137] B1. High-temperature calcination - water washing and impurity removal;

[0138] Calcine the desulfurized gypsum at 150 °C for 1 h to remove part of the crystal water and volatile impurities, wash it with water to remove soluble salts and impurities such as unreacted limestone, and improve the purity of the desulfurized gypsum;

[0139] B2. Composite modification with ferrous sulfate - borax;

[0140] Add 0.8% ferrous sulfate and 0.2% borax to the desulfurized gypsum after impurity removal in B1 and grind them together to obtain crystal form - controlled gypsum. The ferrous ions in ferrous sulfate can participate in the hydration reaction of gypsum and change the crystal growth environment; borax can delay the hydration rate of gypsum and promote the directional growth of AFt crystals;

[0141] B3. Stirring - sieving homogenization;

[0142] Put the crystal form - controlled gypsum in B2 into a stirring device and stir it at a speed of 150 r / min for 20 min, then sieve it through a 100 - mesh sieve to obtain homogenized desulfurized gypsum, removing large - particle agglomerates and ensuring the uniformity of gypsum particles;

[0143] B4. Surface compounding with nano - zinc oxide;

[0144] Disperse the homogenized desulfurized gypsum in B3 and 0.3% nano - zinc oxide (particle size 30 nm) ultrasonically (power 250 W) in absolute ethanol for 40 min, and then dry it to obtain composite gypsum; nano - zinc oxide can fill the pores of gypsum, improve its impermeability and antibacterial properties; obtain high - strength and corrosion - resistant desulfurized gypsum;

[0145] Step three: Frost - resistance modification of ferrite cement;

[0146] C1. Pneumatic separation for impurity removal;

[0147] Remove light impurities and dust from the raw material of ferrite cement (calcareous raw material, aluminous raw material and ferrous raw material with a mass ratio of 5:2:3) through a pneumatic separation device;

[0148] C2. Synergistic modification with spodumene - potassium sulfate;

[0149] Add 3% spodumene (lithium ions generated by the decomposition of spodumene during calcination can participate in the hydration reaction and change the structure of hydration products) and 0.6% potassium sulfate (potassium sulfate can promote the formation of ettringite and improve the frost - resistance performance) to the raw material and grind it to obtain modified cement raw material;

[0150] C3. Stirring for homogenization;

[0151] Put the modified cement raw material in C2 into a planetary stirring device and stir it at a speed of 250 r / min for 30 min to obtain homogenized raw material, making the raw material and additives fully mixed evenly to ensure the consistency of the properties of each part;

[0152] C4. Calcination;

[0153] Calcine the C3 homogenous raw material at 1300 °C to obtain freeze-thaw resistant clinker; make the internal structure of the clinker more dense and improve its freeze-thaw cycle resistance;

[0154] Step Four: Gradient compounding of water reducing agents;

[0155] D1. Swelling: Add HPMC (hydroxypropyl methyl cellulose ether) to warm water at 25 °C and stir at a speed of 60 r / min for 20 min until it is completely dissolved to form a transparent colloid;

[0156] D2. Compound: Add polycarboxylic acid mother liquor and pre-swollen PAA / QCS-CA hydrogel aqueous solution in sequence, stir at a speed of 150 r / min for 25 min, add nano-silica pre-dispersed in ethanol solution, and continue to stir until the particles are uniform;

[0157] The PAA / QCS-CA hydrogel is selected from Chen Runlan, Liang Ziyi, Wang Xinyue, etc. Preparation and properties of acrylic acid / chitosan quaternary ammonium salt-citric acid tough wet adhesion hydrogel [J]. Journal of Fujian Normal University (Natural Science Edition), 2024, 40(06): 1-8.

[0158] The ratio of the polycarboxylic acid mother liquor, PAA / QCS-CA hydrogel, HPMC and nano-silica is 1.5:0.1:0.3:0.2;

[0159] D3. Crosslinking: Heat up to 45 °C and carry out high-speed shearing at 250 r / min for 15 min to obtain a viscosity-increasing water reducing agent;

[0160] Step Five: Step-by-step compounding;

[0161] E1. Premixing of cementitious materials;

[0162] Mix 60 parts of freeze-thaw resistant clinker, 20 parts of chloride-resistant steel slag micro powder and 8 parts of high-strength corrosion-resistant desulfurized gypsum to obtain cementitious materials, stir at a speed of 100 r / min for 5 min to make the three cementitious materials fully mixed and uniform. During the stirring process, the active components of the chloride-resistant steel slag micro powder and the high-strength corrosion-resistant desulfurized gypsum interact with the freeze-thaw resistant clinker to form a preliminary hydration product skeleton, providing a basis for subsequent compounding;

[0163] E2. Addition and mixing of admixtures;

[0164] Add 0.8 part of admixture to the cementitious materials, the stirring speed is 150 r / min, and the stirring time is 8 min to ensure that the admixture is evenly dispersed in the cementitious materials to obtain a viscosity-increasing cementitious material; the admixture includes a viscosity-increasing water reducing agent, a thickening agent and an air-entraining agent with a mass ratio of 1:0.05:0.01;

[0165] Thickening agent: Hydroxypropyl methylcellulose is used to increase the viscosity of concrete, improve its segregation resistance and self-compacting property;

[0166] E3. Aggregate addition and mixing;

[0167] Coarse and fine aggregates are added to the thickening cementitious material;

[0168] Coarse aggregate: Crushed stones with a particle size of 5 mm are selected, and the mud content does not exceed 1%;

[0169] Fine aggregate: Medium sand with a fineness modulus of 2.3 is used, and the mud content does not exceed 3%;

[0170] 88 parts of coarse aggregate are added and stirred at a speed of 180 r / min for 3 min, then 76 parts of fine aggregate are added and stirring continues for 5 min to uniformly mix the coarse and fine aggregates with the cementitious material, obtaining a concrete mixture;

[0171] E4. Water addition and final mixing;

[0172] 22 parts of water are slowly added to the concrete mixture to obtain high-durability ferroaluminate cement-based self-compacting concrete. During the water addition process, the stirring speed is maintained at 200 r / min and the stirring time is 10 min to allow the water to fully participate in the hydration reaction, ensuring that the fluidity, cohesiveness and water retention of the concrete reach the optimal state.

[0173] Example 3: This example provides a preparation method of high-durability ferroaluminate cement-based self-compacting concrete, including the following steps:

[0174] Step 1. Chloride resistance modification of steel slag powder;

[0175] A1. Citric acid - malic acid composite acid etching;

[0176] A mixed solution of 6% citric acid and 3% malic acid (pH = 3.2) is used to soak the steel slag at 58 °C for 2.5 h (liquid-solid ratio 4.8:1) to obtain acid-etched steel slag. The chelating effect of citric acid accelerates the dissolution of iron rust, and the hydroxyl group of malic acid enhances the affinity with the steel slag surface. The two work together to increase the exposure rate of active sites on the steel slag surface;

[0177] A2. Aging treatment;

[0178] The steel slag is placed in an environment with a relative humidity of 70% and a temperature of 25 °C for 5 days for aging treatment to make the performance of the steel slag more stable, obtaining chloride-resistant steel slag powder;

[0179] Step 2. Crystal form regulation of desulfurized gypsum;

[0180] B1. High-temperature calcination - water washing and impurity removal;

[0181] Calcine the desulfurized gypsum at 180 °C for 2 h to remove some crystal water and volatile impurities, wash it with water to remove soluble salts and impurities such as unreacted limestone, and improve the purity of the desulfurized gypsum;

[0182] B2. Composite modification with ferrous sulfate - borax;

[0183] Add 1.3% ferrous sulfate and 0.3% borax to the desulfurized gypsum after impurity removal in B1 and grind them together to obtain crystal form - controlled gypsum. The ferrous ions in ferrous sulfate can participate in the hydration reaction of gypsum and change the crystal growth environment; borax can delay the hydration rate of gypsum and promote the directional growth of AFt crystals;

[0184] B3. Stirring - sieving homogenization;

[0185] Put the crystal form - controlled gypsum in B2 into a stirring device and stir it at a speed of 220 r / min for 22 min, then sieve it through a 180 - mesh sieve to obtain homogenized desulfurized gypsum, removing large - particle agglomerates and ensuring the uniformity of gypsum particles;

[0186] B4. Surface compounding with nano - zinc oxide;

[0187] Ultrasonically disperse the homogenized desulfurized gypsum in B3 and 0.4% nano - zinc oxide (particle size 38 nm) in absolute ethanol (power 300 W) for 50 min, and then dry it to obtain composite gypsum; nano - zinc oxide can fill the pores of gypsum and improve its impermeability and antibacterial properties; obtain high - strength and corrosion - resistant desulfurized gypsum;

[0188] Step three. Frost - resistance modification of ferroaluminate cement;

[0189] C1. Pneumatic separation for impurity removal;

[0190] Remove light impurities and dust from the raw material of ferroaluminate cement (calcareous raw material, aluminous raw material and ferrous raw material with a mass ratio of 5:2:3) through a pneumatic separation device;

[0191] C2. Synergistic modification with spodumene - potassium sulfate;

[0192] Add 4% spodumene (lithium ions generated by the decomposition of spodumene during calcination can participate in the hydration reaction and change the structure of hydration products) and 0.9% potassium sulfate (potassium sulfate can promote the formation of ettringite and improve the frost - resistance performance) to the raw material and grind it to obtain modified cement raw material;

[0193] C3. Stirring for homogenization;

[0194] Put the modified cement raw material in C2 into a planetary stirring device and stir it at a speed of 320 r / min for 41 min to obtain homogenized raw material, making the raw material and additives fully mixed evenly and ensuring the consistency of the performance of each part;

[0195] C4. Calcination;

[0196] Calcine the C3 homogeneous raw material at 1380 °C to obtain freeze-thaw resistant clinker, making the internal structure of the clinker more dense and improving its freeze-thaw cycle resistance ability;

[0197] Step Four: Gradient compounding of water reducing agents;

[0198] D1. Swelling: Add HPMC (hydroxypropyl methyl cellulose ether) into warm water at 33 °C, stir at a speed of 80 r / min for 30 min until it is completely dissolved to form a transparent colloid;

[0199] D2. Compound: Add polycarboxylic acid mother liquor and pre-swollen PAA / QCS-CA hydrogel aqueous solution in sequence, stir at a speed of 210 r / min for 26 min, add nano-silica pre-dispersed in ethanol solution, and continue to stir until the particles are uniform;

[0200] The PAA / QCS-CA hydrogel is selected from Chen Runlan, Liang Ziyi, Wang Xinyue, etc. Preparation and properties of acrylic acid / chitosan quaternary ammonium salt-citric acid tough wet adhesion hydrogel [J]. Journal of Fujian Normal University (Natural Science Edition), 2024, 40(06): 1-8.

[0201] The ratio of the polycarboxylic acid mother liquor, PAA / QCS-CA hydrogel, HPMC and nano-silica is 1.5:0.1:0.3:0.2;

[0202] D3. Crosslinking: Heat up to 52 °C and perform high-speed shearing at 320 r / min for 21 min to obtain a viscosity-increasing water reducing agent;

[0203] Step Five: Step-by-step compounding;

[0204] E1. Premixing of cementitious materials;

[0205] Mix 67 parts of freeze-thaw resistant clinker, 28 parts of chloride-resistant steel slag powder and 11 parts of high-strength corrosion-resistant desulfurized gypsum to obtain cementitious materials, stir at a speed of 130 r / min for 8 min to make the three cementitious materials fully mixed evenly. During the stirring process, the active components of chloride-resistant steel slag powder and high-strength corrosion-resistant desulfurized gypsum interact with the freeze-thaw resistant clinker to form a preliminary hydration product skeleton, providing a basis for subsequent compounding;

[0206] E2. Addition and mixing of admixtures;

[0207] Add 1.1 parts of admixtures to the cementitious materials, stir at a speed of 180 r / min for 10 min to ensure that the admixtures are evenly dispersed in the cementitious materials to obtain viscosity-increasing cementitious materials; The admixtures include a viscosity-increasing water reducing agent, a thickening agent and an air-entraining agent with a mass ratio of 1.2:0.08:0.03;

[0208] Thickening agent: Hydroxypropyl methylcellulose is used to increase the viscosity of the concrete, improve its segregation resistance and self-compacting property;

[0209] E3. Aggregate addition and mixing;

[0210] Coarse and fine aggregates are added to the viscosity-increasing cementitious material;

[0211] Coarse aggregate: Crushed stones with a particle size of 10 mm are selected, and the mud content does not exceed 1%;

[0212] Fine aggregate: Medium sand with a fineness modulus of 3.0 is used, and the mud content does not exceed 3%;

[0213] 120 parts of coarse aggregate are added and mixed at a speed of 200 r / min for 5 min, then 98 parts of fine aggregate are added and mixing continues for 6 min to make the coarse and fine aggregates and the cementitious material evenly mixed, obtaining a concrete mixture;

[0214] E4. Water addition and final mixing;

[0215] 32 parts of water are slowly added to the concrete mixture to obtain high-durability ferroaluminate cement-based self-compacting concrete. During the water addition process, the mixing speed is maintained at 230 r / min and the mixing time is 12 min to allow the water to fully participate in the hydration reaction and ensure that the fluidity, cohesiveness and water retention of the concrete reach the optimal state.

[0216] Comparative example 1: The difference between this comparative example and Example 3 is that when preparing the freeze-thaw resistant clinker, it does not go through the steps of grinding and modifying with spodumene and potassium sulfate powder.

[0217] Step three is specifically: C1. The ferroaluminate cement raw meal is passed through a pneumatic separation device to remove light impurities and dust;

[0218] C2. The raw meal is ground;

[0219] C3. The raw meal is mixed to obtain a homogenized raw meal;

[0220] C4. The homogenized raw meal is calcined to obtain clinker.

[0221] Comparative example 2: The difference between this comparative example and Example 3 is that PAA / QCS-CA hydrogel is not added during the preparation of the viscosity-increasing water reducing agent.

[0222] Comparative example 3: The difference between this comparative example and Example 3 is that desulfurized gypsum is directly selected and its crystal form is not regulated.

[0223] Comparative example 4: The difference between this comparative example and Example 3 is that steel slag powder is directly selected and its chloride resistance modification is not carried out.

[0224] Comparative Example 5: The difference between this comparative example and Example 3 is that PAA / QCS-CA hydrogel was not added during the preparation of the tackifier water reducer, and the crystal form of the desulfurized gypsum was not regulated.

[0225] Experimental Example 1: Frost resistance test;

[0226] According to the rapid freezing method in the Standard for Test Methods of Long-Term Performance and Durability of Concrete (GB / T 50082-2024), prismatic specimens with dimensions of 100 mm × 100 mm × 400 mm were prepared, with 3 specimens in each group, and the number of cycles was ≥ 300 times. The mass loss rate (%) and the retained dynamic elastic modulus (%) were measured.

[0227] The results are shown in Table 1:

[0228] Table 1

[0229]

[0230] Analysis of the data in the above table shows that by adding spodumene and potassium sulfate powder for grinding modification, stirring and homogenization, and high-temperature calcination to the raw meal, the frost resistance of the concrete was significantly improved.

[0231] Experimental Example 2: Salt crystallization erosion test;

[0232] Referring to the sulfate erosion resistance test method (sodium sulfate solution immersion method) in the Standard for Test Methods of Long-Term Performance and Durability of Concrete (GB / T 50082-2024), cubic specimens with dimensions of 100 mm × 100 mm × 100 mm were prepared, with 6 specimens in each group. The immersion solution was: 5% solution, and the immersion cycle was: soak for 24 h → dry for 24 h, and the drying temperature was (60 ± 5) °C, with 150 cycles. The mass loss rate Rm1 (%), surface crack width L (mm), and compressive strength loss rate Rp (%) were measured.

[0233] The results are shown in Table 2:

[0234] Table 2

[0235]

[0236] Analysis of the data in the above table shows that regulating the crystal form of the desulfurized gypsum can significantly improve the sulfate erosion resistance of the concrete. Although the PAA / QCS-CA hydrogel itself cannot improve the sulfate erosion resistance, its compounding with high-strength corrosion-resistant desulfurized gypsum can produce a synergistic effect on the sulfate erosion resistance of the concrete.

[0237] Experimental Example 3: Chloride ion penetration resistance test;

[0238] According to the electric flux method in the Standard for Test Methods of Long-Term Performance and Durability of Concrete (GB / T 50082-2024), prepare: cylindrical specimens with dimensions of Φ100mm×50mm, 3 specimens in each group, test voltage: 60V, test time: 6h, and calculate the electric flux Φ (C).

[0239] The results are shown in Table 3:

[0240] Table 3

[0241]

[0242] Analysis of the data in the above table shows that the steel slag powder with resistance to chlorine obtained by composite acid etching and aging has played a significant role in improving the chloride ion penetration resistance of concrete.

[0243] Experimental Example 4: Self-compacting property detection;

[0244] According to the Technical Specification for Application of Self-compacting Concrete (JGJ / T 283-2012), test the slump flow loss rate SF% and V-funnel filling time T (s) for 1h.

[0245] Among them, the smaller the slump flow loss rate and the shorter the V-funnel filling time, the better the fluidity of the surface concrete, which can flow smoothly in the formwork and fill every corner, including those with complex shapes. Even in areas with dense steel bars, it can fully fill the gaps between the steel bars by virtue of its own fluidity.

[0246] The results are shown in Table 4:

[0247] Table 4

[0248]

[0249] Analysis of the data in the above table shows that by controlling the crystal form of desulfurized gypsum, it can improve the self-compacting performance of concrete. The better the fluidity of the surface concrete, it can flow smoothly in the formwork with complex shapes and fill every corner. Even in areas with dense steel bars, it can fully fill the gaps between the steel bars by virtue of its own fluidity.

[0250] Experimental Example 5: Quick-setting and early-strength performance detection;

[0251] According to the Standard for Test Methods of Physical and Mechanical Properties of Concrete (GB / T50081-2019), prepare cubic specimens with dimensions of 100mm×100mm×100mm, 3 specimens in each group, and test the compressive strength P (MPa) at the ages of 1d, 3d, and 7d.

[0252] The results are shown in Table 5:

[0253] Table 5

[0254]

[0255] Analysis of the data in the above table shows that the PAA / QCS-CA hydrogel enables the early strength of concrete to grow rapidly, can quickly reach a relatively high strength, can significantly shorten the project duration, and accelerate the construction progress. After the PAA / QCS-CA hydrogel is compounded with high-strength and corrosion-resistant desulfurized gypsum, a synergistic effect is produced on improving the rapid hardening and early strength performance of concrete.

[0256] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly durable ferroaluminate cement-based self-compacting concrete, characterized in that, By weight, it includes the following components: 60 - 70 parts of frost - resistant and thaw - resistant clinker; 20 - 30 parts of chlorine - resistant steel slag micro - powder; 8 - 13 parts of high - strength and corrosion - resistant desulfurized gypsum; 0.8 - 1.3 parts of admixture; 88 - 124 parts of coarse aggregate; 76 - 116 parts of fine aggregate; 22 - 38 parts of water; The frost - resistant and thaw - resistant clinker is obtained by removing impurities through air separation from calcareous, aluminous, and ferrous raw materials, grinding and modifying with spodumene and potassium sulfate powder, stirring and homogenizing, and high - temperature calcination; The chlorine - resistant steel slag micro - powder is obtained through composite acid etching and aging; The high - strength and corrosion - resistant desulfurized gypsum is obtained through composite modification with ferrous sulfate and borax, stirring, sieving, and homogenizing, and surface compounding with nano - zinc oxide.

2. The highly durable ferroaluminate cement-based self-compacting concrete according to claim 1, characterized in that, The admixture includes a viscosity - increasing and water - reducing agent, a thickening agent, and an air - entraining agent with a mass ratio of 1 - 1.5:0.05 - 0.1:0.01 - 0.05; The viscosity - increasing and water - reducing agent is obtained by swelling HPMC and then stirring and heating with polycarboxylic acid mother liquor, PAA / QCS - CA hydrogel, and nano - silicon dioxide under shear; 3. A method for preparing a highly durable ferroaluminate cement-based self-compacting concrete as described in claim 1 or 2, characterized in that, It includes the following steps: Step 1: Chlorine - resistance modification of steel slag micro - powder; A1. Composite acid etching with citric acid - malic acid; Soak steel slag with a mixed solution of citric acid and malic acid to obtain acid - etched steel slag; A2. Aging treatment to obtain chlorine - resistant steel slag micro - powder; Step 2: Crystal form regulation of desulfurized gypsum; B1. High - temperature calcination - water washing to remove impurities; Calcine the desulfurized gypsum at a low temperature and wash it with water to remove soluble salts and unreacted limestone and other impurities; B2. Composite modification with ferrous sulfate - borax; Add ferrous sulfate and borax to the desulfurized gypsum after impurity removal in B1 and grind them together to obtain crystal - form - regulated gypsum; B3. Stirring - sieving and homogenizing; Stir and sieve the crystal - form - regulated gypsum in B2 to obtain homogenized desulfurized gypsum; B4. Surface compounding with nano - zinc oxide; Ultrasonically disperse the homogenized desulfurized gypsum in B3 and nano - zinc oxide in absolute ethanol, and dry to obtain high - strength and corrosion - resistant desulfurized gypsum; Step 3: Frost - resistance modification of ferroaluminate cement; C1. Air separation to remove impurities; Remove light impurities and dust from the raw material of ferroaluminate cement through an air separation device; C2. Synergistic modification with spodumene - potassium sulfate; Add spodumene and potassium sulfate to the raw material and grind to obtain modified cement raw material; C3. Stirring and homogenizing; C4. Calcination to obtain frost - resistant and thaw - resistant clinker; Step 4: Gradient compounding of water - reducing agents; D1. Swelling; Add HPMC to warm water and stir until completely dissolved to form a transparent colloid; D2. Compound; Sequentially add polycarboxylic acid mother liquor, the pre - swollen aqueous solution of PAA / QCS - CA hydrogel, stir, add nano - silicon dioxide pre - dispersed in ethanol solution, and continue to stir until the particles are uniform; D3. Cross - linking; Raise the temperature and perform high - speed shearing to obtain a viscosity - increasing and water - reducing agent; Step 5: Step - by - step compounding; E1. Premixing of gelling materials; Mix the frost - resistant and thaw - resistant clinker, chlorine - resistant steel slag micro - powder, and high - strength and corrosion - resistant desulfurized gypsum to obtain a gelling material; E2. Addition and mixing of admixtures; Add the admixture to the gelling material and stir evenly; E3. Addition and stirring of aggregates; Add coarse and fine aggregates to the viscosity - increasing gelling material and mix evenly to obtain a concrete mixture; E4. Addition of water and final stirring; Add water to the concrete mixture to obtain high - durability ferroaluminate cement - based self - compacting concrete.

4. The preparation method of the high-durability ferroaluminate cement-based self-compacting concrete according to claim 3, characterized in that, Step 1 is specifically as follows: A1. Soak steel slag in a mixed solution of 4 - 7% citric acid and 2 - 4% malic acid at 45 - 65°C for 2 - 3 h to obtain acid-etched steel slag; A2. Place it in an environment with a relative humidity of 60% - 80% and a temperature of 20 - 30°C for 3 - 5 days for aging treatment to obtain chloride-resistant steel slag micropowder.

5. The highly durable ferroaluminate cement-based self-compacting concrete according to claim 3 and its preparation method are characterized in that, Step 2 is specifically as follows: B1. Calcinate desulfurized gypsum at 150 - 200°C for 1 - 2 h, and wash it with water to remove soluble salts and impurities such as unreacted limestone; B2. Add 0.8 - 1.5% ferrous sulfate and 0.2 - 0.4% borax to the desulfurized gypsum after impurity removal in B1 and grind them together to obtain crystal form-controlled gypsum; B3. Put the crystal form-controlled gypsum in B2 into a stirring device, stir at a speed of 150 - 250 r / min for 20 - 30 min, and screen it through a 100 - 200 mesh sieve to obtain homogenized desulfurized gypsum; B4. Ultrasonically disperse the homogenized desulfurized gypsum in B3 and 0.3 - 0.5% nano-zinc oxide with a particle size of 30 - 40 nm in absolute ethanol for 40 - 70 min, and obtain high-strength and corrosion-resistant desulfurized gypsum after drying.

6. The preparation method of the highly durable ferroaluminate cement-based self-compacting concrete according to claim 3, characterized in that, Step 3 is specifically as follows: C1. Remove light impurities and dust from the raw material of ferroaluminate cement through a pneumatic separation device; C2. Add 3 - 5% spodumene and 0.6 - 1.1% potassium sulfate to the raw material and grind it to obtain modified cement raw material; C3. Put the raw material in C2 into a planetary stirring device, stir at a speed of 250 - 350 r / min for 30 - 45 min to obtain homogenized raw material; C4. Calcinate the homogenized raw material in C3 at 1300 - 1400°C to obtain freeze-thaw resistant clinker.

7. The preparation method of the high-durability ferroaluminate cement-based self-compacting concrete according to claim 3, characterized in that, Step 4 is specifically as follows: D1. Add HPMC to warm water at 25 - 35°C, stir at a speed of 60 - 100 r / min for 20 - 40 min until it is completely dissolved to form a transparent colloid; D2. Add polycarboxylic acid mother liquor and pre-swollen PAA / QCS-CA hydrogel aqueous solution in sequence, stir at a speed of 150 - 250 r / min for 25 - 35 min, add nano-silica pre-dispersed in ethanol solution, and continue to stir until the particles are uniform; D3. Raise the temperature to 45 - 60°C, and perform high-speed shearing at 250 - 350 r / min for 15 - 25 min to obtain a viscosity-increasing water reducer.

8. The preparation method of the high-durability ferroaluminate cement-based self-compacting concrete according to claim 3, characterized in that, Step 5 is specifically as follows: E1. Mix the freeze-thaw resistant clinker, chloride-resistant steel slag micropowder and high-strength and corrosion-resistant desulfurized gypsum to obtain a cementitious material, and stir at a speed of 100 - 150 r / min for 5 - 10 min; E2. Add an admixture to the cementitious material, with a stirring speed of 150 - 200 r / min and a stirring time of 8 - 12 min; E3. Add fine and coarse aggregates to the viscosity-increasing cementitious material and mix them evenly to obtain a concrete mixture; E4. Slowly add water to the concrete mixture to obtain high-durability ferroaluminate cement-based self-compacting concrete.

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