Functional mineral admixture as well as preparation method and application thereof

Abstract

The invention relates to a functional mineral admixture and a preparation method and application thereof, the functional mineral admixture comprises 20-30 parts of basalt fiber powder; 20-30 parts of alumina wear-resistant ceramic powder; 45 to 55 parts of polymeric alcohol amine modified calcium aluminoferrite powder; 2-4 parts of non-encrypted dispersed silica powder; 2-4 parts of water repellent powder; the functional mineral admixture is prepared by taking polyalkylol amine modified calcium aluminoferrite powder as an anti-abrasion reaction component A, compounding aluminum oxide wear-resistant ceramic powder, basalt fiber powder and non-densified dispersed silica powder as an anti-abrasion reinforcing component B, weighing the anti-abrasion reaction component A, the anti-abrasion reinforcing component B and water repellent powder according to the proportion, and stirring. Compared with the prior art, when the functional mineral admixture is doped into concrete, the abrasion resistance of the concrete can be greatly improved, the used materials are environment-friendly and pollution-free, and the functional mineral admixture can be widely applied to concrete engineering such as airports, wharfs, power station dams and river banks.

Description

Technical Field

[0001] This invention relates to the field of concrete materials technology, and in particular to a functional mineral admixture, its preparation method, and its application. Background Technology

[0002] In hydraulic concrete environments such as dam spillways, sand-laden water flows can cause damage to the concrete surface through impact, friction, and cutting, leading to problems such as abrasion, erosion, porosity, and cavitation. These problems not only pose safety hazards to the hydraulic engineering structure but also result in high costs and difficult repairs for subsequent maintenance.

[0003] Currently, over 70% of the concrete dams in operating hydropower stations in China suffer from erosion damage, which seriously affects the durability of the concrete and the functionality of the project. Therefore, solving the problem of concrete's resistance to erosion is now urgent.

[0004] Traditional erosion-resistant admixtures are primarily composed of silica fume. Their improvement in erosion resistance works by using secondary hydration to densify the microstructure of concrete and reduce microscopic defects. However, as an erosion-resistant mineral admixture, silica fume has a limited overall effect on improving the erosion resistance of concrete. Furthermore, the addition of silica fume can increase concrete shrinkage, potentially leading to shrinkage cracks; it also promotes early hydration heat release, posing risks such as temperature difference cracks to large-volume hydraulic concrete structures.

[0005] Given the shortcomings of traditional methods, many researchers have proposed new approaches to improve the abrasion resistance of concrete. Among them, the scheme with patent application number CN117985965A mainly uses active components such as fly ash, slag powder, and nano-silica, as well as components that regulate volume shrinkage, such as shrinkage-reducing agents and expansion agents. This scheme primarily improves the abrasion resistance of concrete indirectly by reducing shrinkage cracks through the secondary hydration effect of the active components and the regulation of volume stability by shrinkage-reducing and expansion agents. However, this patent does not directly evaluate the effect on improving abrasion resistance.

[0006] Patent application CN119306438A utilizes tungsten slag and ultrafine tungsten slag powder, leveraging the high hardness and wear resistance of tungsten slag to improve the erosion resistance of hydraulic concrete, achieving a certain degree of improvement. However, tungsten slag is an industrial waste generated during the production of ammonium tungstate, typically containing various toxic components such as lead, mercury, arsenic, and molybdenum, as well as chemical components like sodium carbonate and sodium hydroxide. If tungsten slag is used in hydraulic concrete, these pollutants are easily dispersed during concrete erosion and service life, posing significant environmental safety hazards, which limits the application of this method.

[0007] In addition, the patent application with patent number CN118724535A mainly uses copper-plated steel fibers with a length of 12-13mm to improve the impact and abrasion resistance of concrete. However, steel fiber reinforced concrete has problems such as high cost and poor workability, and it will also change the shape and properties of concrete, which limits its application in hydraulic concrete. Summary of the Invention

[0008] The purpose of this invention is to provide a functional mineral admixture, its preparation method and application, to improve the impact and abrasion resistance of concrete, and the materials used are environmentally friendly and pollution-free.

[0009] The objective of this invention can be achieved through the following technical solutions: One objective of this invention is to provide a functional mineral admixture comprising the following components in the indicated weight ratios: 20-30g of basalt fiber powder; Alumina wear-resistant ceramic powder 20~30; Polyolamine-modified calcium aluminoferrite powder 45~55; Unrefined dispersed silica powder 2~4; Water-repellent powder 2~4; Among them, the polymerized alkanolamine-modified calcium aluminoferrite powder is used as the impact and abrasion resistant reaction component A, and the alumina wear-resistant ceramic powder, basalt fiber powder, and non-dense dispersed silica powder are compounded as the impact and abrasion resistant reinforcing component B.

[0010] Preferably, the basalt fiber powder has a diameter of 7-20 μm, an aspect ratio of ≥10, a tensile strength of ≥4000 MPa, an elastic modulus of ≥100 GPa, and an elongation at break of ≥3%.

[0011] The basalt fiber powder used in this invention is a product obtained by shaving and grinding continuous basalt filaments. At the microscopic level, it consists of fine fiber particles with an aspect ratio greater than 10 and possesses excellent mechanical properties. This basalt fiber powder can act as a bridge in the system, not only improving the tensile strength of the cementitious substrate but also significantly enhancing its deformation capacity, thereby improving the energy absorption capacity of concrete under external forces, i.e., its impact and abrasion resistance. Compared to glass fiber, basalt fiber powder has stronger resistance to alkali corrosion in the alkaline environment of cement-based materials (pH value typically higher than 12.4), thus exhibiting superior long-term service performance. Furthermore, because the density of basalt is close to that of concrete aggregate, the fiber powder can achieve good dispersion in concrete; and compared to conventional 6-20mm long fibers, it functions in concrete in a near-powder form, without negatively impacting the flowability of the concrete.

[0012] Preferably, the alumina wear-resistant ceramic powder is α-Al2O3 alumina wear-resistant ceramic powder.

[0013] Preferably, the alumina content is ≥99% by mass, the α-phase alumina content is ≥95%, and the bulk density is ≥3.65 g / cm³. 3 Mohs hardness ≥ 9.0, Rockwell hardness ≥ 85 HRA, Vickers hardness ≥ 8 GPa, compressive strength ≥ 850 MPa, flexural strength ≥ 290 MPa, fracture toughness KIC ≥ 4.8 MPa·m 1 / 2。

[0014] Preferably, the alumina wear-resistant ceramic powder has a fineness of 150-200 mesh.

[0015] Preferably, the fineness of the polymerized alkanolamine-modified calcium aluminoferrite powder is 300-400 μm. 2 / kg.

[0016] More preferably, the 28-day compressive strength of the polymerized alkanolamine-modified calcium aluminoferrite powder is ≥42.5 MPa.

[0017] Preferably, the polyolamine-modified calcium aluminoferrite powder is obtained by co-milling calcium aluminoferrite monoore and polyolamine.

[0018] Preferably, the mass of the polymeric alkanolamine is 0.3‰ to 0.5‰ of the mass of calcium aluminoferrite ore.

[0019] Preferably, the polymeric alcohol amine is selected from one or more of triethanolamine, triisopropanolamine, and diethanol monoisopropanolamine.

[0020] Preferably, the chemical formula of the calcium aluminoferrite monoore is Ca2Al. x Fe 2-x O5, where x ranges from 0.2 to 0.6.

[0021] In this invention, the calcium aluminoferrite (Ca2Al) x Fe 2-x The value of x for O5 ranges from 0.2 to 0.6, for the following reasons: Calcium aluminoferrite (Ca2Al) x Fe 2-x The activity of O5 is closely related to the Al / Fe ratio. When x is below 0.2, calcium aluminoferrite (Ca2Al) x Fe 2-x The mineral phase structure of O5 is relatively stable, resulting in low hydration activity and a low degree of reaction in the early stages of hydration. While the hydration products such as iron-calcium aluminate and iron colloid produced in the reaction can play an anti-abrasion role in the system, the effect is limited. When x is higher than 0.6, with the increase of Al phase doping, calcium aluminoferrite (Ca2Al)... x Fe2-x The Fermi level of O5 decreases, and its reactivity increases rapidly. This not only leads to excessively rapid heat generation in the early stage of hydration, increasing the risk of temperature difference cracks caused by concentrated heat of hydration; but also the excessively rapid formation rate of hydration products in the early stage reduces the density of the structure formed by the interweaving of hydration products, which is not conducive to improving impact resistance and wear resistance.

[0022] In this invention, alkanolamines and calcium aluminoferrite are co-milled. During this process, the alkanolamines not only act as grinding aids but also react with Fe... 3+ And Al 3+ A complexation reaction occurs, thereby increasing the Fe concentration in the solution. 3+ And Al 3+ The degree of supersaturation. This effect not only increases the solubility and reactivity of calcium aluminoferrite, but also promotes the formation of calcium aluminoferrite hydration products, thereby improving the anti-wear effect.

[0023] Preferably, the SiO2 mass percentage content in the un-densified dispersed silicon micropowder is greater than 99%, and the specific surface area is greater than 20 m². 2 / g.

[0024] Preferably, the hydrophobic agent is a polysiloxane hydrophobic agent based on an organosilicon powder resin.

[0025] More preferably, the polysiloxane hydrophobic agent is an organosilicon powder resin that appears as a light white, flowing powder. Its main components are siloxane compounds, along with dispersion and adsorption mixtures.

[0026] In this invention, the water-repellent agent plays a role in the system to improve the water penetration resistance of hydraulic concrete, reduce the intrusion and transmission of various corrosive media with water as the medium in the hydraulic concrete, and thus improve the durability and service performance of the hydraulic concrete under the impact of water flow.

[0027] The second objective of this invention is to provide a method for preparing the aforementioned functional mineral admixture, comprising the following steps: S1: Calcium aluminoferrite and polymeric alcohol amine are ground together according to the formula to obtain anti-impact abrasion reaction component A; S2. Alumina wear-resistant ceramic powder, basalt fiber powder and non-dense dispersed silica powder are mixed according to the formula to obtain a mixed powder. The mixed powder is dispersed in water, stirred and ultrasonicated to obtain a uniform slurry, and vacuum dried to constant weight to obtain agglomerated powder. The agglomerated powder is then dispersed using a powder deagglomeration and dispersing machine to prepare impact and abrasion-resistant reinforcing component B. S3. Take the anti-impact reaction component A, anti-impact reinforcement component B, and water-repellent powder according to the proportion, and mix them with a dry mortar mixer for 8-12 minutes to obtain the functional mineral admixture.

[0028] Preferably, in step S1, the preparation process of the calcium aluminoferrite monoore is as follows: S1.1 Weigh analytical grade CaCO3, Al2O3 and Fe2O3 as raw materials according to stoichiometric ratio, mix the three and grind them together to prepare raw material. The residue of the raw material on an 80μm square mesh sieve should be controlled below 10%. S1.2 Add water at a ratio of 5-7% of the raw material mass and mix evenly, then press into raw material blocks; place the raw material blocks in an oven at 90-120℃ and dry until constant weight; S1.3. After drying, the raw material blocks are pre-fired at 850-950℃ for 30-40 minutes. After pre-firing, the temperature is raised to 1280-1320℃ to complete the calcination. S1.4 After calcination, the sample is taken out and left to stand for 35-45 minutes, and then quenched by rapid air cooling to obtain clinker. S1.5 Grind the above clinker to a specific surface area of ​​350-400 m². 2 / kg can be used to produce calcium aluminoferrite monoore.

[0029] More preferably, in step S1.2, water is added at a ratio of 6% of the raw material mass and mixed evenly, and then pressed into raw material blocks.

[0030] More preferably, in step S1.2, the drying temperature is 105°C.

[0031] More preferably, in step S1.3, the pre-firing temperature is 850-950℃.

[0032] Preferably, in step S2, the preparation process of the basalt fiber powder is as follows: basalt is used as raw material, melted at 1450-1500℃ and drawn into fibers, and then the continuous fiber filaments are cut, ground and sieved to finally obtain the basalt fiber powder.

[0033] Preferably, in step S2, the alumina wear-resistant ceramic powder is prepared as follows: using alumina with a mass fraction greater than 99% and a particle size of 70-120μm as raw material, it is first sintered at a high temperature of 1200-1500℃ for 2-4 hours, and after sintering, it is cooled to finally process it into α-type alumina wear-resistant ceramic powder with a mesh size of 150-200 and a near-spherical shape.

[0034] More preferably, the sintering temperature is 1450°C and the sintering time is 3 hours.

[0035] More preferably, the mass ratio of the mixed powder to water is 1:4-6, and more preferably 1:5.

[0036] More preferably, the mixing time of the dry mortar mixer is 10 minutes.

[0037] The third objective of this invention is to provide an application of the aforementioned functional mineral admixture in concrete.

[0038] More preferably, the functional mineral admixture is widely used in concrete engineering projects such as airports, docks, power plant dams, and river embankments.

[0039] More preferably, the concrete containing functional mineral admixtures can be used as hydraulic concrete and has high resistance to erosion and abrasion.

[0040] Preferably, the amount of the functional mineral admixture in concrete is 5% to 10% based on the total weight of the cementitious materials.

[0041] More preferably, the dosage is an externally added dosage.

[0042] More preferably, the application of the functional mineral admixture in concrete includes the following steps: when mixing concrete, the functional mineral admixture is added at an additional 5% to 10% of the total amount of cementitious materials, and then (impact-resistant) concrete is prepared through molding, demolding and curing.

[0043] More preferably, the application of the functional mineral admixture in concrete can be implemented according to the following steps: S1. Calcium aluminoferrite (chemical formula Ca2Al) prepared by grinding, mixing, drying, calcining, and extremely cooling analytically pure CaCO3, Al2O3, and Fe2O3. x Fe 2-x O5, where x ranges from 0.2 to 0.6, and a polymeric alcohol amine (triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, or one or more) in a mass ratio of 0.03% to 0.05% are placed together in a ball mill and ground to 300-400 μL. 2 / kg fineness, to obtain anti-impact and abrasion reactive component A; S2. Alumina wear-resistant ceramic powder, basalt fiber powder, and non-dense dispersed silica powder are mixed at a mass ratio of 20~30:20~30:2-4. Water at a mass ratio of 5 times or more is used as the dispersion medium. The mixed powder is added to the water and stirred. After ultrasonic dispersion, a uniform slurry is formed. The slurry is dried to constant weight in a vacuum drying oven. The dried agglomerated powder is then dispersed using a powder deagglomeration and dispersing machine to prepare impact and abrasion-resistant reinforcing component B. S3. Take the anti-impact reaction component A, anti-impact reinforcing component B, and water-repellent powder according to the production raw material formula, and force-stir for 10 minutes using a dry mortar mixer to obtain the functional mineral admixture of the present invention. S4. During the mixing process of concrete, the functional mineral admixture mentioned above is added at a dosage of 5% to 10% of the total amount of cementitious materials. After molding, demolding and curing, impact-resistant concrete can be obtained.

[0044] This invention is the first to propose a functional mineral admixture composed of basalt fiber powder, alumina wear-resistant ceramic powder, calcium aluminoferrite powder, polymeric alkanolamine, non-dense dispersed silica powder, and a water-repellent agent powder to improve the impact and abrasion resistance of concrete. In this invention, the components work synergistically: the non-dense dispersed silica powder combined with alumina wear-resistant ceramic powder forms a high-hardness, wear-resistant phase; the non-dense dispersed silica powder combined with basalt fiber powder achieves microstructural toughening of hydraulic concrete; the polymeric alkanolamine-modified calcium aluminoferrite powder generates highly impact- and wear-resistant hydration products; and the water-repellent agent effectively prevents external water intrusion.

[0045] Compared to conventional methods that enhance concrete strength and improve its abrasion resistance by adjusting water-cement ratio, sand ratio, and paste-aggregate ratio, this invention, based on the synergistic effect of the aforementioned multiple aspects, successfully avoids the problems of increased brittleness and limited improvement in abrasion resistance caused by simply increasing concrete strength, achieving a significant improvement in the abrasion resistance of concrete. Furthermore, the materials used do not contain hazardous waste such as tungsten slag, making them environmentally friendly and reliable. Hydraulic concrete prepared using this functional mineral admixture exhibits a significantly increased abrasion resistance ratio to 130%-160% and a compressive strength ratio to over 110%, while the overall material is environmentally friendly and pollution-free.

[0046] Compared with the currently widely used technology that uses silica fume as an impact and abrasion resistant additive, the functional mineral admixture of this invention, when added to concrete, exhibits good volume stability and can avoid excessive concrete shrinkage caused by the addition of silica fume, thereby reducing the generation of shrinkage cracks.

[0047] Furthermore, compared to traditional methods of enhancing concrete's impact and abrasion resistance using silica powder, fibers, etc., the material of this invention only requires the addition of powder during construction, making the process more convenient and efficient. It not only effectively improves the impact and abrasion resistance and durability of concrete, ensuring the stability of the project under water flow impact and significantly extending its service life, but also reduces the frequency of subsequent maintenance. Regarding later maintenance costs, products using this functional mineral admixture have significantly lower maintenance costs compared to products without this material, resulting in a longer service life and lower later maintenance costs.

[0048] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention provides a functional mineral admixture by compounding basalt fiber powder, alumina wear-resistant ceramic powder, calcium aluminoferrite powder, polyolamine, non-dense dispersed silica powder and water-repellent powder. When this admixture is added to concrete, it can significantly improve the impact and abrasion resistance of concrete, and the materials used are environmentally friendly and pollution-free.

[0049] (2) In this invention, the polymerized alkanolamine-modified calcium aluminoferrite powder is used as the anti-impact abrasion reaction component A, which is obtained by co-milling alkanolamine and calcium aluminoferrite. The calcium aluminoferrite contains Ca2Al... x Fe 2-x The x value of O5 is limited to the range of 0.2-0.6, which gives calcium aluminoferrite a certain hydration activity. Modification with polymeric alcohol amines can further promote the formation of calcium aluminoferrite hydration products. These hydration products have high impact and wear resistance, thereby improving the impact and wear resistance of concrete.

[0050] (3) In this invention, alumina wear-resistant ceramic powder, basalt fiber powder, and non-dense dispersed silica powder are used as impact and abrasion resistant reinforcing component B. Among them, the alumina wear-resistant ceramic powder is α-Al2O3 alumina wear-resistant ceramic powder with a Mohs hardness of up to 9; the basalt fiber powder is a fine fiber particle with an aspect ratio greater than 10, with excellent mechanical properties, which can improve the tensile strength, deformation capacity and impact and abrasion resistance of cement substrate through bridging effect; the non-dense dispersed silica powder combined with alumina wear-resistant ceramic powder forms a high-hardness wear-resistant phase, and the non-dense dispersed silica powder combined with basalt fiber powder realizes micro-toughening of hydraulic concrete, which can further improve the impact and abrasion resistance.

[0051] (4) The water-repellent agent in this invention is a polysiloxane water-repellent agent system of organosilicon powder resin, which can effectively improve the water penetration resistance of hydraulic concrete and improve the durability and service performance of hydraulic concrete under water flow impact.

[0052] (5) Based on the synergistic effect of multiple aspects, the present invention has achieved an excellent improvement in the impact resistance of concrete. The hydraulic concrete prepared by this functional mineral admixture has a significantly improved impact resistance strength ratio to 130%-160% and a compressive strength ratio to over 110%. Moreover, the material as a whole does not contain hazardous waste such as tungsten slag, and has the characteristics of being environmentally friendly and pollution-free. It conforms to the principles of green chemistry and is widely applicable to concrete projects such as airports, docks, power station dams, and river embankments. Attached Figure Description

[0053] Figure 1 The following are actual images of concrete samples after impact and abrasion tests: (a) Comparative Example 1; (b) Example 1. Detailed Implementation

[0054] This embodiment is implemented based on the technical solution of the present invention, and provides detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiment.

[0055] Unless otherwise specified, the reagents, methods, instruments, and equipment used in this invention are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0056] A functional mineral admixture comprises the following components in parts by weight: 20-30g of basalt fiber powder; Alumina wear-resistant ceramic powder 20~30; Polyolamine-modified calcium aluminoferrite powder 45~55; Unrefined dispersed silica powder 2~4; Water-repellent powder 2~4; Among them, the polymerized alkanolamine-modified calcium aluminoferrite powder is used as the impact and abrasion resistant reaction component A, and the alumina wear-resistant ceramic powder, basalt fiber powder, and non-dense dispersed silica powder are compounded as the impact and abrasion resistant reinforcing component B.

[0057] The diameter of the basalt fiber powder is 7-20μm, the aspect ratio is ≥10, the tensile strength of the precursor fiber is ≥4000MPa, the elastic modulus is ≥100GPa, and the elongation at break is ≥3%.

[0058] The alumina wear-resistant ceramic powder is α-Al₂O₃ alumina wear-resistant ceramic powder, wherein the mass percentage content of α-phase alumina is ≥95%, and the bulk density is ≥3.65 g / cm³. 3 Mohs hardness ≥ 9.0, Rockwell hardness ≥ 85 HRA, Vickers hardness ≥ 8 GPa, compressive strength ≥ 850 MPa, flexural strength ≥ 290 MPa, fracture toughness KIC ≥ 4.8 MPa·m 1 / 2 The fineness is 150-200 mesh.

[0059] The fineness of the polyolamine-modified calcium aluminoferrite powder is 300-400 μm. 2 / kg, the polyolamine-modified calcium aluminoferrite powder is obtained by co-milling calcium aluminoferrite ore and polyolamine, wherein the mass of the polyolamine is 0.3‰~0.5‰ of the mass of calcium aluminoferrite ore.

[0060] The polymeric alkanolamine is selected from any one or more of triethanolamine, triisopropanolamine, and diethanolmonoisopropanolamine, and the chemical formula of the calcium aluminoferrite monoore is Ca2Al. x Fe 2-x O5, where x ranges from 0.2 to 0.6.

[0061] The SiO2 mass percentage content of the un-densified dispersed silica powder is greater than 99%, and the specific surface area is greater than 20m². 2 / g.

[0062] The water-repellent agent is a polysiloxane water-repellent agent, which is an organosilicon powder resin.

[0063] The preparation method of the aforementioned functional mineral admixture includes the following steps: S1: Calcium aluminoferrite and polymeric alcohol amine are ground together according to the formula to obtain anti-impact abrasion reaction component A; S2. Alumina wear-resistant ceramic powder, basalt fiber powder and non-dense dispersed silica powder are mixed according to the formula to obtain a mixed powder. The mixed powder is dispersed in water, stirred and ultrasonicated to obtain a uniform slurry, and vacuum dried to constant weight to obtain agglomerated powder. The agglomerated powder is then dispersed using a powder deagglomeration and dispersing machine to prepare impact and abrasion-resistant reinforcing component B. S3. Take the anti-impact reaction component A, anti-impact reinforcement component B, and water-repellent powder according to the proportion, and mix them with a dry mortar mixer for 8-12 minutes to obtain the functional mineral admixture.

[0064] In step S1, the preparation process of calcium aluminoferrite monoore is as follows: S1.1 Weigh analytical grade CaCO3, Al2O3 and Fe2O3 as raw materials according to stoichiometric ratio, mix the three and grind them together to prepare raw material. The residue of the raw material on an 80μm square mesh sieve should be controlled below 10%. S1.2 Add water at a ratio of 5-7% of the raw material mass and mix evenly, then press into raw material blocks; place the raw material blocks in an oven at 90-120℃ and dry until constant weight; S1.3. After drying, the raw material blocks are pre-fired at 850-950℃ for 30-40 minutes. After pre-firing, the temperature is raised to 1280-1320℃ to complete the calcination. S1.4 After calcination, the sample is taken out and left to stand for 35-45 minutes, and then quenched by rapid air cooling to obtain clinker. S1.5 Grind the above clinker to a specific surface area of ​​350-400 m². 2 / kg can be used to produce calcium aluminoferrite monoore.

[0065] In step S2, the preparation process of basalt fiber powder is as follows: basalt is used as raw material, melted at 1450-1500℃ and drawn into fibers, and then the continuous fiber filaments are cut, ground and sieved to finally obtain the basalt fiber powder.

[0066] In step S2, the alumina wear-resistant ceramic powder is prepared as follows: using alumina with a mass fraction greater than 99% and a particle size of 70-120μm as raw material, it is first sintered at a high temperature of 1200-1500℃ for 2-4 hours. After sintering, it is cooled and finally processed into α-type alumina wear-resistant ceramic powder with a mesh size of 150-200 and a near-spherical shape.

[0067] When the above-mentioned functional mineral admixtures are used to prepare concrete, the dosage of the functional mineral admixtures in the concrete is 5% to 10% based on the total weight of the cementitious materials.

[0068] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0069] Example 1: Functional mineral admixtures were prepared according to the following steps: S1, calcium aluminoferrite monomineralic Ca2Al 0.5 Fe 1.5 O5, along with 0.03% (by mass) diethanolmonoisopropanolamine, was ground together in a ball mill to a powder concentration of 350 μL. 2 / kg fineness, to obtain anti-impact and abrasion reactive component A; S2. Alumina wear-resistant ceramic powder, basalt fiber powder, and non-dense dispersed silica powder are mixed in a mass ratio of 25:25:2.5. Water is used as a dispersion medium, and the mixed powder is added to the water. After stirring, the mixture is ultrasonically dispersed to form a uniform slurry. The slurry is dried to constant weight in a vacuum drying oven. The dried agglomerated powder is then dispersed using a powder deagglomeration and dispersing machine to prepare impact and abrasion-resistant reinforcing component B. S3. According to the production raw material formula, measure the anti-impact reaction component A, anti-impact reinforcing component B, and water-repellent powder in a ratio of 52.5:50:3, and use a dry powder mortar mixer to forcibly mix for 10 minutes to obtain the functional mineral admixture. S4. During the mixing process of concrete, the functional mineral admixture mentioned above is added at a dosage of 8% of the total amount of cementitious materials. After molding, demolding, and curing, impact-resistant concrete can be obtained.

[0070] The basalt fiber powder has a fiber diameter of 7-20 micrometers, an aspect ratio ≥10, a tensile strength of 4200 MPa, an elastic modulus of 102 GPa, and an elongation at break of 3.1%. The alumina wear-resistant ceramic powder has an alumina content of 97% and a bulk density of 3.68 g / cm³. 3 Mohs hardness 9.0, Rockwell hardness 88 HRA, Vickers hardness 8.2 GPa, compressive strength 860 MPa, flexural strength 310 MPa, fracture toughness KIC 4.9 MPa·m 1 / 2The fineness is 180 mesh. The chemical formula of calcium aluminoferrite monoore is Ca2Al. 0.5 Fe 1.5 O5.

[0071] Example 2: Functional mineral admixtures were prepared according to the following steps: S1, calcium aluminoferrite monomineralic Ca2Al 0.2 Fe 1.8 O5, along with 0.03% (by mass) diethanolmonoisopropanolamine, was ground together in a ball mill to a powder concentration of 360 μL. 2 / kg fineness, to obtain anti-impact and abrasion reactive component A; S2. Alumina wear-resistant ceramic powder, basalt fiber powder, and non-dense dispersed silica powder are mixed in a mass ratio of 20:30:2.5. Water is used as a dispersion medium, and the mixed powder is added to the water. After stirring, the mixture is ultrasonically dispersed to form a uniform slurry. The slurry is dried to constant weight in a vacuum drying oven. The dried agglomerated powder is then dispersed using a powder deagglomeration and dispersing machine to prepare impact and abrasion-resistant reinforcing component B. S3. According to the production raw material formula, measure the anti-impact reaction component A, anti-impact reinforcing component B, and water-repellent powder in a ratio of 52.5:45:2, and use a dry powder mortar mixer to forcibly mix for 10 minutes to obtain the functional mineral admixture. S4. During the mixing process of concrete, the functional mineral admixture mentioned above is added at a dosage of 8% of the total amount of cementitious materials. After molding, demolding, and curing, impact-resistant concrete can be obtained.

[0072] The basalt fiber powder has a fiber diameter of 7-20 micrometers, an aspect ratio ≥10, a tensile strength of 4200 MPa, an elastic modulus of 102 GPa, and an elongation at break of 3.1%. The alumina wear-resistant ceramic powder has an alumina content of 97% and a bulk density of 3.68 g / cm³. 3 Mohs hardness 9.0, Rockwell hardness 88 HRA, Vickers hardness 8.2 GPa, compressive strength 860 MPa, flexural strength 310 MPa, fracture toughness KIC 4.9 MPa·m 1 / 2 The fineness is 180 mesh. The chemical formula of calcium aluminate monomineralic ore is Ca2Al. 0.2 Fe 1.8 O5.

[0073] Example 3: Functional mineral admixtures were prepared according to the following steps: S1, calcium aluminoferrite monomineralic Ca2Al 0.6 Fe 1.4 O5, along with 0.03% (by weight) of diethanolmonoisopropanolamine, was ground together in a ball mill to a powder concentration of 380 μL.2 / kg fineness, to obtain anti-impact and abrasion reactive component A; S2. Alumina wear-resistant ceramic powder, basalt fiber powder, and non-dense dispersed silica powder are mixed in a mass ratio of 20:30:2.5. Water is used as a dispersion medium, and the mixed powder is added to the water. After stirring, the mixture is ultrasonically dispersed to form a uniform slurry. The slurry is dried to constant weight in a vacuum drying oven. The dried agglomerated powder is then dispersed using a powder deagglomeration and dispersing machine to prepare impact and abrasion-resistant reinforcing component B. S3. According to the production raw material formula, measure the anti-impact reaction component A, anti-impact reinforcing component B, and water-repellent powder in a ratio of 42.5:55:2, and use a dry powder mortar mixer to forcibly mix for 10 minutes to obtain the functional mineral admixture. S4. During the mixing process of concrete, the functional mineral admixture is added at a dosage of 10% of the total amount of cementitious materials. After molding, demolding and curing, impact-resistant concrete can be obtained.

[0074] The basalt fiber powder has a fiber diameter of 7-20 micrometers, an aspect ratio ≥10, a tensile strength of 4200 MPa, an elastic modulus of 102 GPa, and an elongation at break of 3.1%. The alumina wear-resistant ceramic powder has an alumina content of 97% and a bulk density of 3.68 g / cm³. 3 Mohs hardness 9.0, Rockwell hardness 88 HRA, Vickers hardness 8.2 GPa, compressive strength 860 MPa, flexural strength 310 MPa, fracture toughness KIC 4.9 MPa·m 1 / 2 The fineness is 180 mesh. The chemical formula for calcium aluminoferrite monoore is Ca2Al. 0.6 Fe 1.4 O5.

[0075] Comparative Example 1: This comparative example serves as the baseline test group. Concrete without added abrasion-resistant agents was subjected to the same molding and curing processes, and its compressive strength and abrasion resistance were tested.

[0076] Comparative Example 2: This comparative example is a control experiment of Example 1, carried out according to the same steps and conditions as Example 1. The difference is that this comparative example uses 8% silica fume as a mineral admixture to improve the impact and abrasion resistance of concrete.

[0077] Comparative Example 3: This comparative example serves as a control experiment for Example 1, conducted according to the same steps, raw materials, and conditions as Example 1. The only difference is that basalt fiber powder is replaced with basalt powder obtained by grinding, and the specific surface area of ​​the basalt powder is 380 m². 2 / kg.

[0078] Comparative Example 4: This comparative example serves as a control experiment for Example 1, conducted according to the same steps, raw materials, and conditions as Example 1. The difference lies in that the calcium aluminoferrite powder in this comparative example has the chemical formula Ca2Al. x Fe 2-x O5, where x takes the value of 0, that is, Ca2FeO5 is used, and Ca2FeO5 is directly ball-milled without using alcohol amine as a grinding aid for grinding.

[0079] Comparative Example 5: This comparative example is a control experiment of Example 1, and is carried out according to the same steps, raw materials and conditions as Example 1. The only difference is that in this comparative example, the alumina wear-resistant ceramic powder α-Al2O3 is replaced with β-Al2O3 of the same fineness.

[0080] Comparative Example 6: This comparative example is a control experiment of Example 1, carried out according to the same steps, raw materials and conditions as Example 1. The only difference is that in this comparative example, the alumina wear-resistant ceramic powder, calcium aluminoferrite, basalt fiber powder, non-dense dispersed silica powder and water-repellent powder are composed in a mass ratio of 80:10:10:2.5:3.

[0081] The collected composite mineral admixtures are to be tested.

[0082] Comparative Example 7: This comparative example is a control experiment of Example 1, carried out according to the same steps, raw materials and conditions as Example 1. The only difference is that in this comparative example, the alumina wear-resistant ceramic powder, calcium aluminoferrite, basalt fiber powder, non-dense dispersed silica powder and water-repellent powder are composed in a mass ratio of 10:10:80:2.5:3.

[0083] Comparative Example 8: This comparative example is a control experiment of Example 1, carried out according to the same steps, raw materials and conditions as Example 1. The only difference is that in this comparative example, the alumina wear-resistant ceramic powder, calcium aluminoferrite, basalt fiber powder, non-dense dispersed silica powder and hydrophobic agent powder are composed in a mass ratio of 10:80:10:2.5:3.

[0084] Performance testing of functional mineral admixtures: The mix proportions of the reference concrete used for testing are shown in Table 1. The slump of the reference concrete was 80-100 mm, and the air content was 4.5 ± 1%. During the test, functional mineral admixtures were added to the concrete using an external admixture method, with the admixture dosage being 5%-10% of the cementitious material dosage. The water content of the concrete remained constant. By adjusting the dosages of sand, aggregate, and admixtures, the concrete achieved the same slump and air content as the reference concrete. After mixing, 150 mm × 150 mm × 150 mm compressive strength specimens and 300 mm diameter, 100 mm high flat cylindrical impact and abrasion resistance specimens were formed. The specimens were cured under standard conditions for 28 days before performance testing.

[0085] Table 1. Standard Concrete Mix Proportion Table

[0086] According to Section 5.21 of the "Test Procedure for Hydraulic Concrete" SL / T 352-2020, the impact and abrasion resistance of the reference concrete and the concrete with functional mineral admixtures are tested respectively. The impact and abrasion resistance ratio is obtained by comparing the impact and abrasion resistance of the reference concrete with that of the tested concrete. According to Sections 5.1 and 5.2 of the "Test Procedure for Hydraulic Concrete" SL / T 352-2020, the compressive strength of the reference concrete and the concrete with functional mineral admixtures are tested respectively. The compressive strength ratio is obtained by comparing the compressive strength of the reference concrete with that of the tested concrete.

[0087] Table 2 Performance Test Results of Composite Mineral Admixtures

[0088] As can be seen from Examples 1 to 3 in Table 2, when the dosage of the functional mineral admixture of the present invention is 5-10%, the impact and abrasion resistance ratio of the concrete is more than 130% and the compressive strength ratio is more than 110% compared with the reference concrete.

[0089] As can be seen from the comparison between Example 1 and Comparative Examples 1 and 2 in Table 2, when traditional silica fume is used as the mineral admixture, although the compressive strength ratio has a significant effect, the impact and abrasion strength ratio is only about 116%, far lower than the value of over 130% achieved using the technical solution of this invention. As can be seen from the comparison between Example 1 and Comparative Example 3 in Table 2, when ordinary basalt powder is used instead of the basalt fiber powder solution of this invention, the impact and abrasion strength ratio decreases significantly due to the loss of the bridging and toughening effect of basalt fiber powder at the microscopic level. As can be seen from the comparison between Example 1 and Comparative Example 4 in Table 2, when the chemical composition and preparation process of the calcium aluminoferrite powder of this invention are not adopted, the compressive strength ratio and impact and abrasion strength ratio of the obtained mineral admixture both decrease significantly due to the instability of the calcium aluminoferrite mineral phase and the loss of the effect of amines on promoting the dissolution and reaction of key elements. As can be seen from the comparison between Example 1 and Comparative Example 5 in Table 2, when the wear-resistant ceramic powder of α-phase alumina without the present invention is used, the alumina cannot provide wear-resistant particles and high-hardness components in the composition and hydraulic concrete, thus significantly reducing the impact and abrasion resistance. Through Example 1 and Comparative Examples 6, 7, and 8, it is evident that the impact and abrasion resistance functional mineral admixtures not formulated according to the mixing ratio of the present invention cannot simultaneously achieve the technical indicators of a compressive strength ratio greater than 110% and an impact and abrasion resistance ratio of 130%.

[0090] Figure 1 (b) Figure 1 (a) are actual images of concrete samples after impact and abrasion tests in Example 1 and Comparative Example 1, respectively. It can be clearly seen that the concrete prepared by the functional mineral admixture of the present invention has superior impact and abrasion resistance.

[0091] In summary, the functional mineral admixture prepared according to the present invention can meet the requirements of compressive strength ratio greater than 110% and abrasion resistance ratio of 130%, which can effectively improve the abrasion resistance of hydraulic concrete and extend the service life of hydraulic concrete in silty water flow.

[0092] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A functional mineral admixture, characterized in that, The components include the following parts by weight: 20-30g of basalt fiber powder; Alumina wear-resistant ceramic powder 20~30; Polyolamine-modified calcium aluminoferrite powder 45~55; Unrefined dispersed silica powder 2~4; Water-repellent powder 2~4; Among them, the polymerized alkanolamine-modified calcium aluminoferrite powder is used as the impact and abrasion resistant reaction component A, and the alumina wear-resistant ceramic powder, basalt fiber powder, and non-dense dispersed silica powder are compounded as the impact and abrasion resistant reinforcing component B.

2. The functional mineral admixture according to claim 1, characterized in that, The basalt fiber powder has a diameter of 7-20 μm, an aspect ratio of ≥10, a tensile strength of ≥4000 MPa, an elastic modulus of ≥100 GPa, and an elongation at break of ≥3%.

3. The functional mineral admixture according to claim 1, characterized in that, The alumina wear-resistant ceramic powder is α-Al2O3 alumina wear-resistant ceramic powder, wherein the mass percentage content of α-phase alumina is ≥95%, and the bulk density is ≥3.65 g / cm³. 3 Mohs hardness ≥ 9.0, Rockwell hardness ≥ 85 HRA, Vickers hardness ≥ 8 GPa, compressive strength ≥ 850 MPa, flexural strength ≥ 290 MPa, fracture toughness KIC ≥ 4.8 MPa·m 1 / 2 The fineness is 150-200 mesh.

4. The functional mineral admixture according to claim 1, characterized in that, The fineness of the polyolamine-modified calcium aluminate powder is 300-400 μm. 2 / kg, the polyolamine-modified calcium aluminoferrite powder is obtained by co-milling calcium aluminoferrite ore and polyolamine, wherein the mass of the polyolamine is 0.3‰~0.5‰ of the mass of calcium aluminoferrite ore.

5. A functional mineral admixture according to claim 4, characterized in that, The polymeric alkanolamine is selected from any one or more of triethanolamine, triisopropanolamine, and diethanolmonoisopropanolamine, and the chemical formula of the calcium aluminoferrite monoore is Ca2Al. x Fe 2-x O5, where x ranges from 0.2 to 0.

6.

6. A functional mineral admixture according to claim 4, characterized in that, The un-densified dispersed silicon micropowder has a SiO2 mass percentage content greater than 99% and a specific surface area greater than 20m². 2 / g.

7. The functional mineral admixture according to claim 1, characterized in that, The hydrophobic agent is a polysiloxane hydrophobic agent, which is an organosilicon powder resin.

8. A method for preparing a functional mineral admixture as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Calcium aluminoferrite and polymeric alcohol amine are ground together according to the formula to obtain anti-impact abrasion reaction component A; S2. Alumina wear-resistant ceramic powder, basalt fiber powder and non-dense dispersed silica powder are mixed according to the formula to obtain a mixed powder. The mixed powder is dispersed in water, stirred and ultrasonicated to obtain a uniform slurry, and vacuum dried to constant weight to obtain agglomerated powder. The agglomerated powder is then dispersed using a powder deagglomeration and dispersing machine to prepare impact and abrasion-resistant reinforcing component B. S3. Take the anti-impact reaction component A, anti-impact reinforcement component B, and water-repellent powder according to the proportion, and mix them with a dry mortar mixer for 8-12 minutes to obtain the functional mineral admixture.

9. The application of a functional mineral admixture as described in any one of claims 1-7 in concrete.

10. The application according to claim 9, characterized in that, The amount of the functional mineral admixture in concrete is 5% to 10% based on the total weight of the cementitious materials.

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