CN115490470B

CN115490470B - High-performance concrete with large-doping-amount undisturbed red mud and preparation process thereof

Info

Publication number: CN115490470B
Application number: CN202211442359.5A
Authority: CN
Inventors: 赵连地
Original assignee: Shandong Jiaotong University
Current assignee: Shandong Jiaotong University
Priority date: 2022-11-18
Filing date: 2022-11-18
Publication date: 2023-03-24
Anticipated expiration: 2042-11-18
Also published as: CN115490470A

Abstract

The invention discloses a high-performance concrete with large-volume undisturbed red mud and a preparation process thereof, belonging to the technical field of building materials and comprising the following components in parts by weight: 15-28 parts of red mud, 12-18 parts of P.O42.5 grade cement, 5-10 parts of blast furnace slag powder, 5-10 parts of steel slag micro powder, 5-8 parts of metal ion solution, 20-30 parts of natural crushed stone, 10-20 parts of natural sand, 4-6 parts of inorganic active excitant, 0.15-0.3 part of organic active excitant, 0.5-1.0 part of high-performance water reducer, 0.5-1.5 parts of composite colloidal polymer dispersant and 3-10 parts of water. The fresh red mud doping amount of the invention adopting the undisturbed Bayer process is 500kg/m ³ The compressive strength of the prepared high-performance concrete reaches C60 and above; is suitable for occasions with high impermeability and high corrosion resistance requirements. Has wide application prospect in the aspects of ocean protection, artificial reef island, municipal pipe gallery and the like.

Description

High-performance concrete with large-doping-amount undisturbed red mud and preparation process thereof

Technical Field

The invention relates to the field of concrete, in particular to high-performance concrete with large-volume undisturbed red mud and a preparation process thereof.

Background

The resource recovery difficulty is large due to small particle size and high alkalinity of the red mud particles, particularly the Bayer process red mud. After about ten years of research and development and exploration, environment-friendly products such as red mud extraction valuable components, building material products, cementing materials for mine filling, roadbed materials, production desulfurizer, water purifying agents, flocculating agents, denitration carriers, steelmaking auxiliary materials and the like are basically formed at present. Most technologies are still in a laboratory stage or an individual pilot stage, only industrialization for producing building materials, roadbed materials and red mud iron selection starts, but the scale is not large and the technologies are not popularized, the main reasons are high cost, expansion cracking and alkali reaction, the appearance and durability of products are affected, in addition, the radioactivity of the red mud baking-free brick is high, the internal and external irradiation indexes IRa and Ir are both more than 1.0 under general conditions, and the application range of the red mud baking-free brick is limited. Therefore, social recognition is low. Bayer process red mud as a filling material (a controllable low-strength backfill material), red mud-based foam concrete, sintered bricks, cement clinker and the like all need to consume a large amount of energy, and the mixing amount is low.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the technical problems, the invention provides a high-performance concrete with large-doping-amount undisturbed red mud and a preparation process thereof.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:

the high-performance concrete with the large-doping-amount undisturbed red mud comprises the following components in parts by weight:

15-28 parts of red mud, 12-18 parts of P.O42.5 grade cement, 5-10 parts of blast furnace slag powder, 5-10 parts of steel slag micro powder, 5-8 parts of metal ionic solution, 20-30 parts of natural crushed stone, 10-20 parts of natural sand, 4-6 parts of inorganic active excitant, 0.15-0.3 part of organic active excitant, 0.5-1.0 part of high-performance water reducer, 0.5-1.5 parts of composite colloidal polymer dispersant and 3-10 parts of water, wherein the metal ionic solution is silica sol loaded metal ionic solution.

Preferably, the composition comprises the following components in parts by weight:

20 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 6 parts of steel slag micro powder, 6 parts of metal ionic solution, 25 parts of natural macadam, 13 parts of natural sand, 4 parts of inorganic activity excitant, 0.25 part of organic activity excitant, 1.0 part of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 3 parts of water.

Preferably, the metal ionic solution contains Fe ³⁺ And Ca ²⁺ Two kinds of metal ions.

Preferably, the metal ion type solution is prepared from 500g of silica sol, 15-30ml of calcium chloride aqueous solution and analytically pure anhydrous FeCl ₃ 40-50g of the mixture is prepared; the particle size of the silica sol is 9-11nm, and the concentration of the calcium chloride aqueous solution is 1-3 g/ml.

Preferably, the inorganic activity excitant comprises, by weight, 40-50 parts of alkali metal silicate, 15-25 parts of alkali metal hydroxide, 5-10 parts of sodium thiosulfate, 5-10 parts of sulfate, 10-15 parts of high-calcium solid waste material and 0-5 parts of hydrotalcite.

Preferably, the alkali metal silicate is any one of potassium silicate and sodium silicate; the alkali metal hydroxide is any one of sodium hydroxide and potassium hydroxide; the high-calcium solid waste material is any one of carbide slag, desulfurized gypsum, titanium gypsum and phosphogypsum; the sulfate is any one of sodium sulfate and potassium sulfate.

Preferably, the organic activating activator is any one of triethanolamine, polyol, polyalcohol amine and triisopropanolamine, and the high-performance water reducing agent is any one of a polycarboxylic acid water reducing agent, a naphthalene water reducing agent and a sulfamate water reducing agent.

Preferably, the composite colloidal polymer dispersant is a mixture of a maleic anhydride copolymer and polyphosphate, and the weight ratio of the maleic anhydride polymer to the polyphosphate is 50:50.

preferably, the maleic anhydride polymer is a polymer of maleic anhydride and tetrafluoroethylene, and the weight ratio of the maleic anhydride to the tetrafluoroethylene is 1:870.

the preparation process of the high-performance concrete with the large-doping-amount undisturbed red mud is characterized by comprising the following steps of:

s1: respectively preparing a composite colloidal polymer dispersant, a metal ion type solution and an inorganic activity excitant for later use, and preparing the rest raw materials in place;

s2: mixing and dissolving a metal ion type solution, a high-performance water reducing agent, an organic activity excitant and water, and stirring to obtain a mixed solution; (all the above are liquid additives, mixing is favorable for homogenizing, and then the liquid additives are mixed into the red mud slurry to improve the dispersion homogeneity and activity excitation of the red mud.)

S3: putting the red mud of the undisturbed Bayer process into a vibrating stirrer, adding a composite colloidal polymer dispersant, stirring for at least 90s, adding a stirring solution, and continuously stirring for 60s to obtain red mud slurry;

s4: putting cement, mineral powder, steel slag micro powder and an inorganic active excitant into the red mud slurry, and stirring to obtain cement-based red mud composite slurry;

s5: the natural broken stone and the natural sand are put into the cement-based red mud composite slurry and stirred to obtain the uniformly mixed high-performance undisturbed red mud concrete with large doping amount.

The invention has the beneficial effects that:

firstly, the invention adopts the red mud of the undisturbed Bayer process, the fresh red mud is fine enough and has no agglomeration phenomenon,the fine particles are spherical or ellipsoidal and the resulting "morphology effect" will increase the fluidity of the slurry. With the increasing of the medium particle size, the fluidity of the slurry is increased. Under the superposition effect of inorganic activity excitant and organic activity excitant, the red mud contains Al ³⁺ 、Si ⁴⁺ It is easier to depolymerize and leach in finer particles than in coarse particles, providing more beneficial components for repolymerization and crystallization.

Secondly, the high alkalinity of the red mud can depolymerize the vitreous body in the blast furnace slag powder and the steel slag micro powder, and accelerate the hydration reaction of the cement and the blast furnace slag powder under the participation of the inorganic active excitant.

Thirdly, the inorganic active excitant can depolymerize the silicon-aluminum component in the raw material to generate aluminum-oxygen tetrahedron and silicon-oxygen tetrahedron, wherein the superfine calcium carbonate (calcium carbonate contained in carbide slag, desulfurized gypsum, titanium gypsum and phosphogypsum) has a nucleation effect, can promote the geopolymerization reaction process of the slurry and improve the crystallinity of the hydration product. The concrete can not only quickly adjust the setting rate of the concrete and has good setting accelerating effect on the cement, but also can enable the performance of the concrete to generate qualitative leap and enhance the strength of the cement red mud composite concrete.

The silicate in the inorganic activity excitant not only can provide an alkaline environment for hydration reaction, but also can be directly used as a silicate crystal to provide basic elements, namely dicalcium silicate, tricalcium silicate and the like are formed; the high-calcium solid waste in the inorganic activity excitant can not only provide an alkaline environment for hydration reaction, but also directly provide calcium ions and provide effective elements for volcanic ash reaction; the sulfate in the inorganic active excitant, such as sodium thiosulfate and sodium sulfate, can accelerate the hydration process of cement, and the sodium sulfate can also accelerate the generation of hydration product calcium sulphoaluminate, thereby accelerating the hydration hardening speed of cement.

Fourthly, the blast furnace slag powder and the steel slag micro powder both contain soluble SiO ₂ 、Al ₂ O ₃ And the like, and water and lime (Ca (OH) generated in hydration reaction) at normal temperature ₂ ) Slow reaction to form insoluble and stable calcium aluminosilicate, i.e. pozzolanic reaction. Active SiO ₂ 、A1 ₂ O ₃ With C in cement ₃ S and C ₂ Ca (OH) produced by hydration of S ₂ And high calcium solid waste reaction in the inorganic active excitant further forms hydrated calcium silicate products which are filled in the pores of the cement concrete, greatly improves the compactness of the cement concrete and simultaneously leads Ca (OH) with lower strength ₂ The crystal is converted into hydrated calcium silicate gel with higher strength, and a series of performances of the red mud-based cement concrete, such as impermeability, frost resistance, corrosion resistance and the like, are remarkably improved.

Fifthly, the organic activity excitant can not only accelerate the hydration reaction of cement, improve the early strength of concrete, but also increase the impermeability of concrete.

And sixthly, the metal ion type solution and the cement hydrate to play a synergistic effect and a superposition effect. The metal ion solution in the components is used as a polymerization reaction catalyst or an inducer and an activation stabilizer, the silica sol is a binder, has the characteristics of strong binding power and excellent dispersibility, and under the coordination of the composite colloidal polymer dispersant, the red mud concrete cohesiveness is enhanced and more homogeneous, and in addition, the supported ferric trichloride (FeCl) ₃ /SiO ₂ ) The product is an important iron catalyst or a heterogeneous catalytic system, and the main component of the tetracalcium aluminoferrite often has the advantages of high reaction speed, good selectivity, simple post-treatment, no need of solvent for reaction and the like, so that the hydration product is promoted to be converted into a more stable hydration product with high strength. Therefore, the method has unique advantages in multi-molecule tandem reaction.

Silica sol loaded calcium chloride (CaCl) in metal ion type solutions ₂ /SiO ₂ ) Has the functions of an early strength agent and provides more calcium ions and active SiO ₂ In the hydration reaction process, the calcareous component has the hydration promotion process, the silica sol micelle is a nano-grade material, has larger adsorption capacity and good dispersibility, can be fully filled into solid matters, ensures that concrete is more compact, and in addition, active SiO ₂ Can participate in hydration reaction to form dicalcium silicate and tricalcium silicate in alkaline environment, and can form with other cementing materialsThe synergistic supplement effect improves the mechanical strength of the cementing material, and the impermeability, freeze-thaw resistance and corrosion resistance of the red mud high-performance concrete are enhanced.

Seventhly, the added composite colloidal polymer dispersing agent can enable a polymer system obtained after tetrafluoroethylene monomer polymerization to have strong adsorption coating property, functional groups such as-OH, COOH and the like can be adsorbed on the surfaces of particles, and the physical and chemical properties of a solid-liquid interface and the interaction among the particles are obviously changed through electrostatic repulsion and steric hindrance, so that red mud particles are coated and isolated from water, and bound water in the red mud is further dissociated; the composite polyphosphate can prevent the sedimentation and the agglomeration of solid particles, leads the red mud to be in a stable suspension state, leads the red mud, the cement and other minerals to have higher dispersion fluidity under the action of vibration, is favorable for the acceleration of the depolymerization-repolymerization-precipitation process, has full hydration reaction and greatly reduces the bleeding property.

Eighth, researches find that the adsorbability of the unique structure of the zeolite and the small amount of boron contained in the zeolite can effectively shield neutron rays, and are the root cause of radiation protection; ba atoms in the barite can cause a part of rays to generate a photoelectric effect, an electron pair effect and a Compton effect, so that the energy of the rays is attenuated; the steel slag micro powder has high density and contains boron element, so the effect can be generated, and partial radioactivity is shielded.

The fresh red mud doping amount of the invention adopting the undisturbed Bayer process is 500kg/m ³ The compressive strength of the prepared high-performance concrete reaches C60 and above; under natural curing, the high-performance concrete structural part disclosed by the invention has no crack generation after being observed for 6 months, and the freeze-thaw resistant cycle times are not lower than 300; the chlorine ion permeability resistance, 56d age and 6h total conductive quantity (C) are less than or equal to 1000; the anti-permeability grade reaches P12; the concrete not only consumes a large amount of red mud, but also is suitable for occasions with high impermeability and high corrosion resistance requirements. Has wide application prospect in the aspects of ocean protection, artificial reef island, municipal pipe gallery and the like.

The invention finally realizes the large-scale comprehensive utilization of the Bayer process red mud, particularly the cooperative resource utilization of the Bayer process red mud and bulk solid wastes such as steel slag micro powder, blast furnace slag powder, recycled aggregate and the like, can reduce the production pressure of waste production enterprises and upstream and downstream thereof, occupy a large amount of land for storage, raise dust, pollute water sources, soil sources, influence ecological potential threats and the like, change the harm into the benefit, is used for rapid and large resource utilization of concrete engineering in various industries, can replace natural resources, reduce the excavation of the natural resources, protect ecological resources and have wide social benefits, obvious economic benefits and ecological environmental benefits.

Drawings

FIG. 1 is a concrete molding specimen of example 1;

FIG. 2 is a cross section of the concrete of example 1 after the test of compressive strength.

Detailed Description

The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The preparation process of the high-performance concrete with large doping amount of undisturbed red mud comprises the following steps:

s1: respectively preparing a composite colloidal polymer dispersant, a metal ion type solution and an inorganic activity excitant for later use, and preparing the rest raw materials in place.

Preparation method of A metal ion type solution

A1: selecting commercially available high-quality silica sol (manufactured by Zhejiang Deliver micro-nano technology Limited company, type: sodium type, specification: JN 10-30/1) with particle size range of 9-11nm and solid content of 30 +/-1%, and weighing 500g; the silica sol has higher specific surface area and can be used for catalyst manufacture and catalyst carriers;

a2: pouring the mixture into a 1000ml flask, heating the mixture in a constant temperature furnace at constant temperature of 100 +/-10 ℃;

a3: adding a calcium chloride solution with the concentration of 1g/ml to 3g/ml into the solution obtained in the step A2, wherein the total mass of calcium chloride is 20g, heating to 100-120 ℃, uniformly stirring by using a glass rod for at least 60 times/min, and stirring until the liquid is homogeneous and has no precipitate;

a4: extract of Chinese medicinal materialsQuasi-weighing powder 50g FeCl ₃ Pouring into a flask, continuously starting a peristaltic pump, uniformly stirring for at least 60 times/min until the upper part and the lower part become light yellow homogeneous sol;

a5: cooling to room temperature.

Preparation method of B inorganic activity excitant

The inorganic activity excitant comprises 47 parts of sodium silicate nonahydrate, 20 parts of sodium hydroxide, 10 parts of sodium thiosulfate, 10 parts of sodium sulfate, 10 parts of carbide slag and 3 parts of hydrotalcite;

b1: preparing a certain mass part of carbide slag, drying the carbide slag in a forced air drying oven at 105 +/-5 ℃, and drying the carbide slag at constant temperature within 30min until the mass difference is within 1 g;

b2: carrying out ultra-pure ultra-fine processing on the carbide slag by mass by adopting a jet mill to ensure that the fineness of the carbide slag reaches more than 6000 meshes;

b3: adding weighed and dried sodium silicate nonahydrate, sodium hydroxide, sodium thiosulfate and sodium sulfate to perform ultra-pure ultra-fine processing, so that the fineness of the sodium silicate nonahydrate, the sodium hydroxide, the sodium thiosulfate and the sodium sulfate can reach more than 6000 meshes;

b4: and (2) adding a certain part of sodium silicate nonahydrate, sodium hydroxide, sodium thiosulfate and sodium sulfate into the mixed solution at one time by adopting an air flow mixer, and mixing for 5-10min to obtain the nanoscale inorganic active excitant.

Preparation method of C composite colloidal polymer dispersant

C1: dissolving tetrafluoroethylene and maleic anhydride in anhydrous ethanol in a ratio of 1:870, taking sodium peroxide as an initiator, polymerizing at the temperature of 70-80 ℃ and under the pressure of 5-8MPa, and fully stirring for 3-5h; generating a maleic anhydride polymer;

c2: spray drying the maleic anhydride polymer at 85-90 deg.C to obtain brown powder, i.e. maleic anhydride copolymer;

c3: mixing maleic anhydride copolymer and sodium tripolyphosphate according to a weight ratio of 50:50, and then the compound colloidal polymer dispersant can be obtained.

S2: mixing and dissolving the metal ion type solution, the sulfamate high-efficiency water reducing agent, the organic activity excitant and water, and stirring for 1-5min at normal temperature to obtain a mixed solution;

s3: adopting a strong vibration stirrer, measuring the water content, then accurately metering, putting the red mud in an undisturbed Bayer process, simultaneously adding a composite colloidal polymer dispersant, strongly stirring and vibrating for 5-10min, then adding a stirring solution, and continuously stirring for 1-5min to obtain red mud slurry;

s4: accurately metering cement, mineral powder, steel slag micropowder and inorganic active excitant, adding into the red mud slurry, and stirring for 1-5min to obtain cement-based red mud composite slurry;

s5: accurately metering coarse and fine aggregates, putting the aggregates into the cement-based red mud composite slurry, and stirring for 1-2min to obtain the uniformly mixed high-performance undisturbed red mud concrete with large doping amount;

s6, placing the high-performance concrete with the large amount of the undisturbed red mud into pressure-resistant, bending-resistant, freezing-resistant and seepage-resistant test moulds respectively, standing for 1d, then removing the moulds, placing the test blocks into a standard curing box, curing for at least 28d, and testing various performance indexes.

The workability of the high-performance concrete with the large-doping-amount undisturbed red mud is tested according to the standard of the performance test method of common concrete mixtures (GB/T50080-2016);

the high-performance concrete test piece with large amount of undisturbed red mud is manufactured according to the test specification of highway engineering cement and cement concrete (JTG 3420-2020);

the performance test of the high-performance concrete with the large-doping-amount undisturbed red mud is carried out according to the standard of test methods for long-term performance and durability of common concrete (GB/T50082-2009);

the performance indexes of the high-performance concrete with the large-doping-amount undisturbed red mud refer to technical Specifications for highway, bridge and culvert construction (JTG/T3650-2020) and technical Specifications for high-performance concrete application (CECS 207: 2006).

Example 1:

the high-performance concrete with the large-doped undisturbed red mud comprises the following components in parts by weight:

20 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 6 parts of steel slag micro powder, 5 parts of metal ionic solution, 25 parts of natural macadam, 13 parts of natural sand, 4 parts of inorganic activity excitant, 0.25 part of organic activity excitant, 1.0 part of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 4 parts of water.

And (3) detection results: the slump of the concrete is 180mm; after removal, see fig. 1 for details. The test block is well formed, no obvious bubbles, holes and cracks exist, no appearance defects such as alkali resistance exist, the 28d compressive strength is 66.5MPa, the breaking strength is 7.1MPa, the anti-permeability grade is P12, a quick freezing method (freezing for 2 hours and melting for 1 hour) is adopted, and when the mass loss is 5%, the repeated freezing and thawing cycle times are 350 times. After the test, the internal section is homogeneous and compact, and has no quality defects such as voids and the like, which is detailed in figure 2. Therefore, the indexes all meet the corresponding grade requirement of C60 high-performance concrete in the technical Specification for highway, bridge and culvert construction (JTG/T3650-2020) and the technical Specification for high-performance concrete application (CECS 207: 2006).

In addition, the internal and external radiation indexes IRa and Ir of the test piece in the embodiment are respectively 0.24 and 0.36 which are both less than 1.0, the chlorine ion permeability resistance in the 56d age and the total conductive quantity (C) of 6h are 915, and the test piece meets the requirements of the current national standard.

Example 2:

16 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 6 parts of steel slag micro powder, 5 parts of metal ionic solution, 25 parts of natural macadam, 17 parts of natural sand, 4 parts of inorganic activity excitant, 0.25 part of organic activity excitant, 1.0 part of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 4 parts of water.

And (3) detection results: the slump of the concrete is 190mm; after the mold is removed, the test block is well formed, no obvious air bubbles, holes and cracks exist, no appearance defects such as alkali resistance exist, the 28d compressive strength is 79.3MPa, the breaking strength is 7.6MPa, the anti-permeability grade is P12, a quick freezing method (freezing for 2 hours and melting for 1 hour) is adopted, and when the mass loss is 5%, the repeated freezing and thawing cycle times are 372. Therefore, under the conditions of reducing the mixing amount of the red mud and increasing the aggregate, the leaching of the silicon-aluminum components in the red mud is easier, the dissolving-crystallizing-precipitating effects of the red mud, the mineral powder and the like are more obvious, the indexes are superior to those in example 1, and the requirements of the corresponding grade of the C70 high-performance concrete in technical Specifications for highway bridge and culvert construction (JTG/T3650-2020) and technical Specifications for high-performance concrete application (CECS 207: 2006) are met.

In addition, the internal and external radiation indexes IRa and Ir of the test piece in the embodiment are respectively 0.15 and 0.29, both are less than 1.0, the chlorine ion permeability resistance in the 56d age and the total conductive quantity (C) in 6h are 850, and the requirements of the current national standard are met.

Example 3:

30 parts of red mud, 15 parts of P.O42.5-grade cement, 5 parts of blast furnace slag powder, 3 parts of steel slag micro powder, 6 parts of metal ion type solution, 20 parts of natural macadam, 10 parts of natural sand, 4 parts of inorganic activity excitant, 0.25 part of organic activity excitant, 1.0 part of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 5 parts of water.

And (3) detection results: the concrete slump is only 140mm; after the mould is removed, the test block is well formed, no obvious appearance defects such as bubbles, holes, cracks and the like exist, and the alkali reaction phenomenon exists locally after 28 days; the 28d compressive strength is 46.5MPa, the flexural strength is 5.1MPa, the impermeability grade is P10, a quick freezing method (freezing for 2h and thawing for 1 h) is adopted, and when the mass loss is 5%, the repeated freezing-thawing cycle times are 225. Therefore, under the condition of increasing the doping amount of the red mud, each index is weaker than that in the example 1, the main reason is that the leaching of the silicoaluminophosphate component in the red mud is difficult along with the increase of the doping amount of the red mud, and the degree of the participation of the inert minerals such as hematite and the like in the hydration reaction is lower. Therefore, the indexes can meet the corresponding grade requirement of C40 high-performance concrete in technical Specification for highway, bridge and culvert construction (JTG/T3650-2020), but the repeated freezing and thawing cycle times do not meet the corresponding requirement in technical Specification for high-performance concrete application (CECS 207: 2006).

Example 4:

20 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 6 parts of steel slag micro powder, 8 parts of metal ionic solution, 25 parts of natural macadam, 12 parts of natural sand, 4 parts of inorganic active excitant, 0.25 part of organic active excitant, 1.5 parts of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 1.5 parts of water.

And (3) detection results: the concrete slump is 185mm; after the mold is removed, the test block is well formed, no obvious air bubbles, holes and cracks exist, no appearance defects such as alkali resistance exist, the 28d compressive strength is 70.6MPa, the breaking strength is 7.5MPa, the anti-permeability grade is P12, a quick freezing method (freezing for 2 hours and melting for 1 hour) is adopted, and when the mass loss is 5%, the repeated freezing and thawing cycle times are 377 times. Therefore, when the mixing amount of the metal ion type solution is increased and the using amount of water is reduced, the mineral dissolution-crystallization-precipitation process in the concrete is accelerated due to the increase of the metal ions, so that the indexes are all superior to those in example 1, and the corresponding grade requirements of the C60 high-performance concrete in technical Specifications for highway and bridge construction (JTG/T3650-2020) and technical Specifications for high-performance concrete application (CECS 207: 2006) are met.

In addition, the internal and external irradiation indexes IRa and Ir of the test piece in this example are 0.31 and 0.44, respectively, both of which are less than 1.0, and meet the requirements of the current national standard.

Example 5:

20 parts of red mud, 15 parts of P.O42.5 grade cement, 6 parts of blast furnace slag powder, 6 parts of steel slag micro powder, 3 parts of metal ion type solution, 24 parts of natural macadam, 12 parts of natural sand, 4 parts of inorganic activity excitant, 0.25 part of organic activity excitant, 1.0 part of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 6 parts of water.

And (3) detection results: the concrete slump is 175mm; after the mould is removed, the test block is well formed, has no obvious appearance defects such as bubbles, holes and the like, but has slight cracks and local alkali resistance; the 28d compressive strength is 52.6MPa, the flexural strength is 5.2MPa, the impermeability grade is P10, a quick freezing method (freezing for 2h and thawing for 1 h) is adopted, and when the mass loss is 5%, the repeated freezing-thawing cycle times are 284 times. Therefore, when the doping amount of the metal ion type solution is reduced and the using amount of water is increased, the metal ions are reduced, so that the mineral dissolution-crystallization-precipitation process in the concrete is reduced, and all indexes are weaker than those in example 1, and the corresponding grade requirements of the freezing-thawing cycle times of the high-performance concrete in technical Specification for high-performance concrete application (CECS 207: 2006) cannot be met.

Example 6:

20 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 4 parts of steel slag micro powder, 5 parts of metal ionic solution, 25 parts of natural macadam, 13 parts of natural sand, 6 parts of inorganic activity excitant, 0.25 part of organic activity excitant, 1.0 part of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 4 parts of water.

And (3) detection results: the concrete slump is 165mm; after the mold is removed, the test block is well formed, no obvious air bubbles, holes and cracks exist, no appearance defects such as alkali resistance exist, the 28d compressive strength is 68.7MPa, the breaking strength is 7.2MPa, the anti-permeability grade is P12, a quick freezing method (freezing for 2 hours and melting for 1 hour) is adopted, and when the mass loss is 5%, the repeated freezing and thawing cycle times are 358 times. Therefore, the activity of the mineral powder, the steel slag micro powder and the red mud can be improved under the conditions of increasing the mixing amount of the inorganic active excitant and reducing the steel slag micro powder, the indexes are superior to those of the embodiment 1, and the corresponding grade requirements of the C60 high-performance concrete in technical Specifications for highway, bridge and culvert construction (JTG/T3650-2020) and technical Specifications for high-performance concrete application (CECS 207: 2006) are met.

In addition, the internal and external irradiation indexes IRa and Ir of the test piece in this example are 0.41 and 0.43, respectively, both of which are less than 1.0, and meet the requirements of the current national standard.

Example 7:

20 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 6 parts of steel slag micro powder, 5 parts of metal ionic solution, 26 parts of natural macadam, 14 parts of natural sand, 2 parts of inorganic activity excitant, 0.25 part of organic activity excitant, 1.0 part of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 4 parts of water.

And (3) detection results: the concrete slump is 185mm; after the mold is removed, the test block is well formed, no obvious air bubbles, holes and cracks exist, no appearance defects such as alkali resistance exist, the 28d compressive strength is 53.3MPa, the breaking strength is 5.7MPa, the anti-permeability grade is P10, a quick freezing method (freezing for 2 hours and melting for 1 hour) is adopted, and when the mass loss is 5%, the repeated freezing and thawing cycle times are 312 times. Therefore, under the condition of reducing the mixing amount of the inorganic active excitant, the activity of the red mud can not be fully excited, and the red mud can not play a role in polymerization and crystallization, so that the indexes are weaker than those in example 1, and the corresponding grade requirements of C60 high-performance concrete in technical Specification for Highway bridge and culvert construction (JTG/T3650-2020) and technical Specification for high-performance concrete application (CECS 207: 2006) can not be met.

Example 8:

20 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 4 parts of steel slag micro powder, 5 parts of metal ionic solution, 25 parts of natural macadam, 13 parts of natural sand, 6 parts of inorganic activity excitant, 0.25 part of organic activity excitant, 1.3 parts of high-performance water reducer, 0.45 part of composite colloidal polymer dispersant and 4 parts of water.

And (3) detection results: the slump of the concrete is only 85mm, and the requirement of transportation of a concrete transport vehicle cannot be met; it can be seen that compared with example 1, the composite colloidal polymer dispersant in this example is reduced, and the colloidal substances (iron hydroxide, etc.) in the red mud play a great retarding role, and even if the amount of the water reducing agent is increased, the overall workability is too poor.

Example 9:

20 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 4 parts of steel slag micro powder, 5 parts of metal ionic solution, 25 parts of natural macadam, 13 parts of natural sand, 6 parts of inorganic activity excitant, 0.25 part of organic activity excitant, 1.0 part of high-performance water reducer, 1.5 parts of composite colloidal polymer dispersant and 3.25 parts of water.

And (3) detection results: the concrete slump is 215mm, and the concrete pumping requirement is met; therefore, the addition of the composite colloidal polymer dispersant can achieve good particle wrapping and dispersing effects on colloidal substances in the red mud, and the overall workability is better than that of example 1 even if the amount of water is reduced.

In addition, the internal and external irradiation indexes IRa and Ir of the test piece in this example are 0.21 and 0.32, respectively, both of which are less than 1.0, and meet the requirements of the current national standard.

Example 10:

20 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 4 parts of steel slag micro powder, 5 parts of metal ionic solution, 25 parts of natural macadam, 13 parts of natural sand, 6 parts of inorganic activity excitant, 0.35 part of organic activity excitant, 1.0 part of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 3.9 parts of water.

And (3) detection results: the concrete slump is 170mm; after the mould is removed, the test block is well formed, obvious air bubbles, holes and cracks are avoided, appearance defects such as alkali resistance and the like are avoided, the 28d compressive strength is 67.5MPa, the breaking strength is 7.2MPa, the anti-permeability grade is P12, a quick freezing method (freezing for 2 hours and melting for 1 hour) is adopted, and when the mass loss is 5%, the number of repeated freezing and thawing cycles is 334. Therefore, the activity of the mineral powder, the steel slag micro powder and the red mud can be excited under the conditions of increasing the mixing amount of the organic active exciting agent and reducing the using amount of water, the indexes are superior to those of example 1, and the requirements of C60 high-performance concrete on the corresponding grade in technical Specification for highway, bridge and culvert construction (JTG/T3650-2020) and technical Specification for high-performance concrete application (CECS 207: 2006) are met.

In addition, the internal and external irradiation indexes IRa and Ir of the test piece in this example are 0.17 and 0.25, respectively, both of which are less than 1.0, and meet the requirements of the current national standard.

Example 11:

20 parts of red mud, 15 parts of P.O42.5-grade cement, 6 parts of blast furnace slag powder, 4 parts of steel slag micro powder, 5 parts of metal ionic solution, 25 parts of natural macadam, 13 parts of natural sand, 6 parts of inorganic activity excitant, 0.10 part of organic activity excitant, 1.0 part of high-performance water reducer, 0.75 part of composite colloidal polymer dispersant and 4.15 parts of water.

And (3) detection results: the slump of the concrete is 200mm; after the mold is removed, the test block is well formed, no obvious air bubbles, holes and cracks exist, no appearance defects such as alkali resistance exist, the 28d compressive strength is 62.2MPa, the breaking strength is 5.8MPa, the anti-permeability grade is P10, a quick freezing method (freezing for 2 hours and melting for 1 hour) is adopted, and when the mass loss is 5%, the repeated freezing and thawing cycle times are 315 times. Therefore, under the conditions of reducing the mixing amount of the organic active exciting agent and increasing the using amount of water, the slump is increased, but the strength, the impermeability and the frost resistance are weaker than those of the example 1, and the organic active exciting agent reduces the influence on the activity of the mineral powder, the steel slag micro powder and the red mud.

In addition, the internal and external irradiation indexes IRa and Ir of the test piece in this example are 0.52 and 0.67, respectively, both of which are less than 1.0, and meet the requirements of the current national standard.

It is to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The high-performance concrete with the large-doped undisturbed red mud is characterized by comprising the following components in parts by weight:

15-28 parts of red mud, 12-18 parts of P.O42.5 grade cement, 5-10 parts of blast furnace slag powder, 5-10 parts of steel slag micro powder, 5-8 parts of metal ionic solution, 20-30 parts of natural crushed stone, 10-20 parts of natural sand, 4-6 parts of inorganic active excitant, 0.15-0.3 part of organic active excitant, 0.5-1.0 part of high-performance water reducer, 0.5-1.5 parts of composite colloidal polymer dispersant and 3-10 parts of water, wherein the metal ionic solution is metal ionic solution loaded by silica sol; the metal ion type solution contains Fe ³⁺ And Ca ²⁺ Two kinds of metal ions; the organic activating excitant is any one of triethanolamine, polyalcohol amine and triisopropanolamine, and the high-performance water reducing agent is any one of polycarboxylic acid water reducing agent, naphthalene water reducing agent and sulfamate water reducing agent;

the preparation method of the metal ion type solution comprises the following steps:

a1: selecting high-quality silica sol sold in the market, wherein the silica sol is produced by Zhejiang Deliver micro-nano technology Limited company and has the model number: sodium type, specification: JN10-30/1, the particle size range of the silica sol is 9-11nm, the solid content is 30 +/-1%, and the weight is weighed to be 500g; the silica sol has higher specific surface area and can be used for catalyst manufacture and catalyst carriers;

a4: accurately weighing 50g of FeCl3 powder, pouring the powder into a flask, continuously starting a peristaltic pump, uniformly stirring for at least 60 times/min until the upper part and the lower part become light yellow homogeneous sol;

a5: cooling to room temperature;

the preparation method of the inorganic activity excitant comprises the following steps:

the inorganic active excitant comprises 47 parts of sodium silicate nonahydrate, 20 parts of sodium hydroxide, 10 parts of sodium thiosulfate, 10 parts of sodium sulfate, 10 parts of carbide slag and 3 parts of hydrotalcite;

b4: adding sodium silicate nonahydrate, sodium hydroxide, sodium thiosulfate and sodium sulfate in a certain proportion by using an air flow mixer at one time, and mixing for 5-10min to obtain a nano-scale inorganic active excitant;

the preparation method of the composite colloidal polymer dispersant comprises the following steps:

c3: mixing maleic anhydride copolymer and sodium tripolyphosphate according to a weight ratio of 50:50, and mixing to obtain the composite colloidal polymer dispersant.

2. The high-performance concrete with the heavily doped undisturbed red mud of claim 1, which is characterized by comprising the following components in parts by weight:

3. The preparation process of the high-performance undisturbed red mud concrete with large doping amount according to any one of the claims 1 to 2, which is characterized by comprising the following steps:

s1: respectively preparing a composite colloidal polymer dispersant, a metal ion type solution and an inorganic activity excitant for later use, and preparing other raw materials in place;

s2: mixing and dissolving a metal ion type solution, a high-performance water reducing agent, an organic activity excitant and water, and stirring to obtain a mixed solution;

s3: putting the red mud of the undisturbed Bayer process into a vibrating stirrer, adding a composite colloidal polymer dispersant, stirring for at least 90s, adding a certain amount of stirring solution, and continuously stirring for 60s to obtain red mud slurry;